Buildings Branch 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 (416) 5857385 July 28, 1988 MEMORANDUM TO: David Hodgson Director Buildings Branch George Wildish Manager Buildings Branch FROM: Ali Arlani Technical Policy Advisor RE: Deterioration of Parking Garages _____________________________________________________________ The Advisory Committee has completed its mandate which included the review of CSA Standard S41387 (Durable Parking Structures) for new parking garages as well as the production of an Advisory Document on the Deterioration, Repair, and Maintenance of Parking Garages. With respect to new construction, the Committee's recommendations regarding CSA Standard S41387 were accepted and was part of the new Code Amendment Package which became effective starting May 20, 1988. In addition, CSA has recalled its Technical Committee to review the Advisory Committee's recommendations. With respect to existing parking structures, the report is now complete and consists of six chapters which address the magnitude of the problem. The report includes an overview chapter; three technical chapters consisting of inspection

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techniques, repair methods, and maintenance and monitoring procedures; as well as two final chapters dealing with enforcement procedures and communication strategies. A copy of this report is attached for your approval. /2

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2 A draft version of the report containing three technical chapters has been available to the public upon request. During the past six months, the Branch has distributed over 400 copies of the draft report in response to industry requests. In addition, members of the Project Coordinating Team have met with many interest groups and have been involved in advisory panels, consumer panels and technical seminars in this field. Due to the high demand for the draft report, I recommend that the three technical chapters (2, 3, & 4) of the final report become public document. We have already initiated the process of an impact study to establish the best method of dealing with this problem. The impact study will be completed over the next three months and include consultation with such interest groups as nonprofit housing agencies, municipalities, building owners, rent review, condominium managers, property managers, Minimum Residential Property Standards Board, CIPREC, CMHC, BOMA, etc. With respect to communication strategies, it is imperative that a pamphlet, outlining the serious problem of parking garage deterioration, be prepared and distributed to owners/property managers, condominium owners and their board members. It would be beneficial to participate in the activities of parking garage projects that are currently being undertaken by other provincial, federal and standard writing organizations. Ali Arlani

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REPORT OF THE ADVISORY COMMITTEE ON THE DETERIORATION, REPAIR AND MAINTENANCE OF PARKING GARAGES Ministry of Housing July 1988 Ontario Buildings Branch

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REPORT OF THE ADVISORY COMMITTEE ON THE DETERIORATION, REPAIR AND MAINTENANCE OF PARKING GARAGES Ministry of Housing Ontario Buildings Branch

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EXECUTIVE SUMMARY In November 1986, the Ministry of Housing formed an Advisory Committee from leading specialists within the Province of Ontario to address matters relating to the deterioration of the provincial stock of parking structures, estimated to be in excess of 3000 structures. The Committee's mandate was to prepare a report, with recommendations, where necessary, to address the $1 billion plus provincial problem of chloride-induced damage to existing parking garages. To ensure that new parking structures would not fail in a similar fashion, the Committee reviewed and recommended the inclusion of CSA Standard S413-87 (Durable Parking Structures) in the Ontario Building Code. The Ontario Building Code requires that new parking structures be designed according to this Standard, effective May 20, 1988. It is hoped that this report may enable the Ministry to put in perspective this technical study with one broader and more complex issue: the rehabilitation of the province's high-rise residential units. The Committee suggests that through the use of the methodology developed in this report for examining damaged parking garages, the province then can proceed to address the more complex technical but joint financial matter, facing it in the building rehabilitation issue. Rapid and progressive structural deterioration of parking structures is essentially caused by corrosion of the reinforcing steel in concrete or the steel tendons in post-tensioned or pre-tensioned concrete. Steel and steel composite structures are also susceptible to these degradation processes. In normally reinforced concrete structures, the corrosion product on the steel reinforcing bars expands to exert tensile forces on the immediate surrounding concrete leading to the concrete's delamination and fracture. The deterioration process is caused by chloride-based, deicing road salts which are carried into parking structures by user traffic. The combination of salt and water produces a salt-laden solution which penetrates the concrete floor slabs and initiates deterioration of unprotected steel by corroding the embedded reinforcing steel. Periodic inspections of parking garage structures are required to ensure the integrity of the load-carrying capacity of the suspended parking floor, as well as to gather information on the condition of the structure so that maintenance and/or repairs can be carried out in a timely and cost-effective manner. Inspection procedures and testing techniques used to assess the

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condition of the various garage components range from simple, straightforward techniques that require no special expertise (ie. visual walk-through inspection) to sophisticated techniques which require the services of a qualified professional engineer.

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Initial deterioration demands regular inspection and periodic repair while advanced deterioration requires major remedial action to redress and halt the deterioration process before structural failure occurs. Apart from executing required repairs at this time, a long-term solution and its implicated cost remain unknown. As such, an important first step is to develop a procedural guideline document based on current knowledge. Repair for the moment should be based on regularly detailed inspections and tests which are supervised by a suitably qualified engineer. Any reasonably effective method of addressing the problem in future must include assessments of initial repair costs; the cost of disruption of use during remedial work; the projected cost of continuing inspection and maintenance; and cost of future repairs. These assessments should include the possible impact of the Tax Act on property owners. Monitoring must form an integral part of effective repair and maintenance programs to ensure public safety and maintain the structural integrity of a garage. Monitoring, through frequent routine walk-through inspections should be conducted to record the progressive condition of the various structural components. Hence, a functional and cost-effective maintenance program can be initiated based on these surveys. In addition, a reserve fund and an orderly work schedule should be established to properly manage the financial impact of any maintenance program. Presently, there is no province-wide legislation requiring mandatory retrofit of damaged structures to ensure safety. Although Section 10 of the Building Code Act allows building officials to declare a structure "unsafe", no objective standard exists to define this term. Province-wide enforcement of mandatory retrofit for damaged parking structures might be ensured by two legislative means: 1) amendments to secure that end within the current provincial Building Code Act and 2) the introduction of new legislation governing certification or the issuing of permits for structures, with permits requiring renewal on a periodic basis. Before a choice is made between these approaches, it is recommended that an impact study be undertaken among all interested parties, and that the legislation on parallel problems by other jurisdictions be analyzed and evaluated. A communication strategy, developed by government and industry, must be implemented to widely inform the public about the nature and extent of the problem as well as the need for repair and maintenance programs. The two recommended levels of communication include: 1) a complete compilation of the Sub-committees' technical reports and of the Advisory Committee's conclusions as a whole; and 2) a summary of the deterioration problem and the recommended solutions in simple layman's terms. The drafts of both documents should be made available to industry and to the general public for comment. In addition, a publicity campaign should be launched to ensure the widest dissemination of the pertinent information in print, by means of advertising and by the organizing of seminars.

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GENERAL CONCLUSIONS o While a few parking structures are so badly damaged as to call for immediate and major remedial action,

deterioration, if irreversible in the remaining majority, can be considered a long-term problem. 1992 is the projected target date for arriving at a comprehensive repair and restoration program which is affordable, effective and enforceable.

o A workplan needs to be developed to allow for pertinent technical research (including the findings of the

present study being conducted by the Canadian Institute of Public Real Estate Companies); to produce additional material performance and supply data; to pursue relevant training programs; and to devise life cycle costing formulae for the various techniques and structures involved. The implementation of the activities outlined in this report may require a new organization.

o The period of time necessary to develop and execute a provincial work-plan will allow owners to fully

assess the economic impact of this problem on those directly affected - the corporate, public and private sectors. The use of the workplan will allow owners to conceive a universal economic framework to support and make viable the unavoidable costs of effectively dealing with it.

o The final major task to be confronted will be the choice and the framing of legislation not only of

enforcing measures to deal with this problem, but imposing the technical standards and regulating the financial framework needed to sustain them. While the present trend within the construction industry is towards deregulation, it must be recognized that this major, unanticipated and unavoidable problem will demand long-term solutions and emphatic legislative measures.

o Some of the future benefits deriving from this study and its consequences include:

(a) exploration of effective preventative measures to guard against similar problems in future parking garages.

(b) applying some of the findings to the problem of high-rise rehabilitation.

(c) increased building industry revenues from export activities, based on similar repair needs of other

countries.

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COMMITTEE MEMBERSHIP CHAIRMAN Alvin J. Houston - Canada Mortgage and Housing Corp. COORDINATORS Ali Arlani - Ministry of Housing Parvaneh B. Cody - Stanford Engineering Ltd. 1) THE DETERIORATION PROBLEM AND INSPECTION TECHNIQUES *Mr. T. Alexander - Construction Control Ltd. Mr. G. Litvan - IRC/NRC Mr. J. Cook - Proctor Redfern Group Mr. J. Ryell - Trow Group Mr. G. Coley - Corrosion Service Ltd. 2) REPAIR METHODS *Mr. J. Bickley - Trow/J.A. Bickley & Assoc. Mr. D. Manning - Min. of Trans. & Comm. Mr. H. Hakamaki - Cluett Royl Restoration Ltd. Mr. B. Halsall - Halsall Robt & Associates Ltd. Mr. P. Jeffs - Foseco Canada Inc. Mr. G. Coley - Corrosion Service Ltd. Mr. F. Edgecombe - The Soc. of the Plastics Industry 3) MAINTENANCE AND MONITORING PROCEDURES *Mr. D. Clark - Del Management Inc. Mr. E. Sanderson - OHC Mr. L. Sie - Morguard Investments Ltd. Mr. L. Peterfy - Toronto Parking Authority 4) ENFORCEMENT METHODS *Mr. B. Loudon, Q.C. - Housner, Henry, Loudon and Syron Mr. Y. Uzumeri - City of North York Mr. C. Proctor - Canada Mortgage and Housing Corp. Mr. G. Feher - Ministry of Housing 5) COMMUNICATION PROGRAM *Mr. M. Shirlaw - Construction Control Ltd. Mr. B. Nayyar - Ministry of Government Services Mr. B. Avard - PreCon

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Mr. M. Rich - Lortex Associates Mr. R. Querengesser - Private Owner OTHER MEMBERS Mr. R. Daniel - CIPREC Mr. J. Warren - Morrison Hershfield Inc. * Chairman

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TABLE OF CONTENTS

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EXECUTIVE SUMMARY .......................................... i COMMITTEE MEMBERSHIP ....................................... iv TABLE OF CONTENTS .......................................... v LIST OF TABLES ............................................. vii LIST OF FIGURES ........................................... viii CHAPTER 1.0 OVERVIEW .......................................... 1 1.1 INTRODUCTION ................................. 2 1.2 OUTPUTS ...................................... 3 1.3 FINDINGS ..................................... 3 1.4 CONCLUSIONS .................................. 5 1.5 RECOMMENDATIONS .............................. 7 1.6 DISCUSSION ................................... 8 1.7 RESEARCH NEEDS ............................... 12 1.8 DATA REPOSITORY .............................. 14 1.9 PUBLIC RESPONSE TO COMMUNICATION STRATEGY .... 14 2.0 THE DETERIORATION PROBLEM AND

INSPECTION TECHNIQUES ............................. 16 2.1 INTRODUCTION ................................. 17 2.2 SCOPE ........................................ 17 2.3 THE NATURE OF THE CORROSION PROCESS .......... 19 2.4 REPAIR OF DETERIORATED GARAGES ............... 21

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2.5 INSPECTION AND TESTING ....................... 23 2.6 SUMMARY OF COMMONLY USED INSPECTION PROCEDURES ........................ 26 2.7 ILLUSTRATIONS ................................ 27

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CHAPTER PAGE 3.0 REPAIR METHODS .................................... 41 3.1 INTRODUCTION ................................. 42 3.2 SAFETY ....................................... 43 3.3 ECONOMIC CONSIDERATIONS ...................... 43 3.4 SUMMARY OF REPAIR METHODS..................... 44 3.5 DECISION CRITERIA ............................ 45 3.6 EVALUATION OF ADVICE ......................... 45

3.7 CONSULTING ENGINEERING SERVICES .............. 46 3.8 REPAIR CONTRACTORS ........................... 47 3.9 EDUCATION .................................... 47 4.0 MAINTENANCE AND MONITORING PROCEDURES ............. 53 4.1 INTRODUCTION ................................. 54 4.2 SCOPE ........................................ 55 4.3 MONITORING PROCEDURES ........................ 59 4.4 MAINTENANCE ROUTINES ......................... 61 4.5 ILLUSTRATIONS ................................ 62 5.0 ENFORCEMENT PROCEDURES ............................ 72 5.1 INTRODUCTION ................................. 73 5.2 ISSUE ........................................ 73 5.3 SUMMARY OF EXISTING REGULATORY FRAMEWORK ..... 73 5.4 OPTIONS ...................................... 74 5.5 DISCUSSION ................................... 75

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5.6 RECOMMENDATIONS .............................. 78 6.0 DEVELOPMENT OF A COMMUNICATION STRATEGY ........... 79 6.1 INTRODUCTION ................................. 80 6.2 OBJECTIVE .................................... 80 6.3 THE COMMUNICATION STRATEGY ................... 82 LIST OF TABLES TABLE PAGE 2.1 Simple Testing and Inspection Procedures .............. 28 3.1 Parking Structure Repair Matrix ....................... 49 4.1 Planned Maintenance Schedule .......................... 63

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LIST OF FIGURES FIGURE PAGE 2.1 Localized collapse of garage roof slab ................ 32 2.2 Surface delamination of floor slab .................... 32 2.3 Surface scaling of floor slab

due to freezing and thawing ........................... 33 2.4 Surface delamination of floor slab

after removal of loose concrete ....................... 34 2.5 Delamination of column ................................ 35 2.6 Deterioration of garage exterior wall ................. 36 2.7 Delamination of beam .................................. 36 2.8 "Chain Drag" Identifying delaminated areas

in top surface of a floor slab ........................ 37 2.9 Testing compressive strength of concrete

sample removed from a floor slab ...................... 37 2.10 Removing sample of concrete from a

floor slab with a core drill .......................... 38 2.11 Testing repaired floor slab to determine the adhesion between the floor slab concrete

and the replacement concrete .......................... 39 3.1 Parking Structure Repair Matrix ....................... 48 4.1 Water leakage through crack in slab soffit ............ 65 4.2 Evidence of water leakage through garage roof slab .... 66 4.3 Suspended slab with water leakage ..................... 67 4.4 Water pond formation at base of column ................ 68 4.5 Spalled floor slab with exposed and

corroded reinforcing steel ............................ 69 4.6 Spalling at base of column with exposed

and corroded reinforcing steel ........................ 69

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4.7 Spalled support ledge face at expansion joint

with exposed reinforcing steel ........................ 70 4.8 Corroded and broken strands

of post-tensioning cable .............................. ............................ 70

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CHAPTER 1 OVERVIEW

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1.0 OVERVIEW 1.1 INTRODUCTION In November 1986, the Ministry of Housing formed an Advisory Committee from leading specialists within the Province of Ontario to address the issue of deteriorating parking garages. A deteriorated parking garage may be defined as a structure which can no longer function efficiently and effectively to meet the original design requirements. The Ministry advised the Committee that, with the thousands of garages in Ontario, varying widely in age, there was a need to coordinate resources to provide an orderly approach to redressing the chlorideinduced damage problem in existing garages. To ensure that new garages would not fail in a similar fashion, the Committee was to review the CSA Standard S41387 (Durable Parking Structures). The need for a communication strategy and realistic but enforceable legislation that took account of affected property owners in the province, were further measures to be considered by the Committee. Accordingly, this report contains a record of the deliberations of the Committee, in the form of Advisory Documents as Chapters 2 6. This Overview provides additional comments regarding the probable impact and benefits of any legislation enacted to address the estimated $1 billion plus provincial problem. It is hoped that the Overview may also enable the Ministry to put into perspective this focused technical study with one other broader and more complex issue: the rehabilitation of the province's highrise residential units. The Committee suggests that through the use of the methodology developed by this Committee to examine damaged parking garages, the province then can proceed to address the more complex technical but joint financial matters, facing it in the building rehabilitation issue. With regard to parking garages only, the Committee had two mandates. A)Pertaining to existing parking garages; prepare a report, with recommendations where necessary, covering the following subjects: Extent of the Deterioration Problem Types of Deterioration

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Inspection Techniques Repair Methods Monitoring Procedures Maintenance Requirements Alternative Enforcement Methods A Communication Program B)Pertaining to new parking garages; review the new CSA Standard S41387 (Durable Parking Structures), when it becomes available, and make recommendations regarding its adoption by the Ontario Building Code.

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1.2 OUTPUTS The Committee has fulfilled its first mandate with the formation of five Subcommittees, individually chaired by specialists in a particular activity, which provided the required advisory documents. These Subcommittees are: Problem Identification and Inspection Techniques Repair Methods Maintenance and Monitoring Procedures Enforcement Methods Communication Program The advisory documents prepared by the Subcommittees as formal outputs, address the needs of existing damaged garages or previously repaired garages and will be found as Chapters 2, 3, 4, 5, and 6 of this report. Pertaining to new parking structures, written submissions from building industry representatives were analyzed along with the Committee's review of CSA Standard S41387. As a result of the Committee's recommendation, this Standard is currently referenced in the Ontario Building Code. The following compendium of findings, conclusions and recommendations contains highlights from the Subcommittees' deliberations and provides a focus for the discussion that concludes this section. 1.3 FINDINGS One significant and possibly overriding finding from the deliberations of the full Committee, is the difficulty of introducing legislation that will be "workable" for all affected parties, when considering the wide range of financing mechanisms used in the construction and maintenance of the troubled buildings. Specific findings from the five Subcommittees follow: Problem Identification and Inspection Techniques: Damage from known concrete deterioration processes, such as sulphate attack, alkali aggregate reaction and freezing and thawing is generally not structurally significant nor

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sufficiently rapid or severe enough to become a significant part of the parking garage problem. Occurrences of these types of concrete deterioration are usually due to specific conditions existing in a particular garage. Rapid and progressive structural deterioration of parking garages is essentially caused by corrosion of the reinforcing steel in concrete or the steel tendons in posttensioned or pretensioned concrete. Structural deterioration due to corrosion can also be found in steel and steel composite structures. Periodic inspections of parking garage structures are required for reasons of safety, in connection with the loadcarrying capacity of suspended parking floors, or the need to gather information on the condition of the structure so that maintenance and/or repairs are carried out in a timely manner and a most costeffective way. Inspection procedures and testing techniques used to assess the condition of the various garage components range from simple, straightforward procedures, to sophisticated techniques which normally require the services of professional engineers. Repair Methods: Reliance must be placed on the experience and judgement of the individual or organization involved in the assessment and repair of the parking garage. Once methods having the most reasonable chance of effectiveness have been identified, consideration must be given to initial repair costs, the costs brought about by the interference with normal use during remedial work, and the expected future maintenance and repair costs. Maintenance and Monitoring Procedures: Although the history of modern parking garage structures is relatively short, it is known that ignoring delamination and spalling will, in most instances, permit the materials decay process to continue. Enforcement Methods: Existing legislation is not effective to ensure a provincewide, uniformly applied retrofit standard for existing structures.

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No provincial legislation exists which would require retrofit of existing structures on a mandatory basis across the province to ensure structural safety. Power under the Planning Act of this province rests with municipalities, which pass bylaws dealing with maintenance and occupancy. Enforcement of these bylaws vary throughout the province. Not all municipalities have adopted such bylaws. At present, there is a provision (Sec. 10) under the Building Code Act (BCA) of this province allowing building officials to take action where a building is structurally "unsafe". However, there is no objective standard at the present time to determine if a building is "unsafe".

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Communication Program: Two categories of property owners need to be reached, classified by their personal or group knowledge or access to applicable technical information. Many large owner groups have appropriate engineering personnel on hand, either on staff or as consultants; condominium owner groups and others may not be as well informed. The method by which the information is distributed is one key to its effectiveness in reaching all those who should be informed, while the form in which the information is reproduced is a key to its being readily understood. 1.4 CONCLUSIONS A major conclusion to be drawn from the overall committee work suggests that the Ministry should develop a communication plan in relation to deteriorating parking garages; the communication plan should encompass both a shortterm strategy and a longterm strategy. In the shortterm, a limited document based on the contents of Chapters 2 6 of this report should be developed prior to enacting legislation. A longterm plan of communication activity based on new understandings of the impact of any proposed legislation should then be considered. The literature indicates that unwanted chlorides can cause the onset of corrosion in steelreinforced concrete, and that continuing corrosion and delamination can be expected. Furthermore, within the lifetime of all parking structures, more than one cycle of repairs in any one structure may be expected. The Ministry should ensure that sufficient technical and economic research is completed before enacting legislation which may not now be sustainable in the courts. Specific conclusions from the five Subcommittees follow: Problem Identification and Inspection Techniques: Corrosion of steel in concrete typically takes place when the chloride concentration and moisture content exceed certain threshold values in the host concrete, and when oxygen is available. Inspection and testing procedures to determine the presence and the impact of this corrosion process may be divided into two

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categories, namely: (a) a simple "walk through" procedure that could result in the identification and definition of a problem, and preparation of records in the form of photographs and drawings detailing the visual appearance of the structure at the time of the "walk through" inspection are required;

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(b) a detailed inspection procedure with test methods carried out under the direction of a suitably experienced engineer to identify the extent of the deterioration. Repair Methods: Without much more research, such as the Canadian Institute of Public Real Estate Companies (CIPREC) Program, no standard recommendations can be developed for repairs. An interim guideline document could be produced based on the stateoftheart currently available. Maintenance and Monitoring Procedures: A trained observer will not be able to overcome problems in an existing structure, but he/she can help extend its useful life by setting up a meaningful maintenance program under the supervision of a trained person to monitor the conditions on a regular basis. Enforcement Methods: To ensure a provincewide standard of enforcement for retrofit of existing structures, two possibilities to consider are as follows: (a)mandatory retrofit under the BCA, recognizing that amendments must be made to the BCA and further regulations filed under that Act; (b)the certification of or issuing of permits for structures, requiring new legislation to authorize the issuing of permits relating to various types of structures, and the renewal of these permits on a periodic basis. Communication Program: Any communications strategy must reach all parties that have any involvement, direct or remote, with parking garages. The two distinct levels of expertise exhibited by this audience with regard to technical knowledge or understanding must be recognized. The communications strategy must identify the form of the written documentation and the method of publicizing and

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distributing it.

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1.5 RECOMMENDATIONS With upwards from 3,000 highrise residential, municipal and commercial parking garages in the Province of Ontario likely to have chlorideinduced corrosion problems in reinforced concrete structures, no single repair strategy will dominate. For the shortterm, the Subcommittees have provided the best technical knowledge currently available in Chapters 2 6 of this report. In the longterm, until all the troubled buildings are stabilized or are removed from the inventory, further technical research, materials supply, manpower training, economic studies, communications activity and legislative impacts must be collectively studied. A workplan needs to be developed. This workplan should cover the time period 1988 to 1992, highlighting the need for additional materials performance data, training programs and life cycle costing formulae developed for various repairs and differing buildings. Specific recommendations from the five Subcommittees follow: Repair Methods: In the shortterm, a guideline document based on the current stateoftheart should be developed by a consultant appointed by the Ministry. Subsequent to the completion of the CIPREC report and any other related research, a standard document for the repair of parking structures should be developed. Maintenance and Monitoring Procedures: Carry out a survey, identifying the type of structure, its components and the condition of those components, irrespective of building age and present condition. Based on these findings, a maintenance program should be established that is functional and cost effective as well as practical in order to complete the structure's economic life. Establish a reserve fund for orderly work schedules. Enforcement Methods: This Subcommittee does not recommend one or the other of the alternatives contained in its conclusions, but strongly recommends that an impact study be performed involving all

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interested parties. It is also recognized that if certification of or permit issuance for structures is to be adopted, there must be a clear and definitive standard for the certifying engineer to follow. A detailed analysis should be made of the legislation from various jurisdictions, other than municipal in scope, prior to the implementation of either of the recommended alternatives.

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Communication Program: Provide two distinct, but parallel publications; one to include the complete reports of the technical Subcommittees, the other to briefly summarize this information in layman's terms to satisfy both the technical and nontechnical audiences, regarding the extent of the parking garage problem and the vital need for repair and maintenance procedures. Produce documents uniform in style; the drafts of these documents to be reviewed by industry and the public. Engage a qualified consultant to ensure uniformity of style, develop suitable mailing lists, organize a suitable advertising campaign and hold seminars throughout the province. 1.6 DISCUSSION The Ontario Ministry of Housing already has underway a Building Industry Strategy Board directed to four traderelated objectives and one statutes and regulatory objective (1). The activities of the Parking Garage Advisory Committee reflect the need to introduce new legislation in one problem area deteriorating parking garages. This should not duplicate, overlap or conflict with existing enforcement practices at a time when the streamlining of existing building enforcement procedures is underway (2). Deteriorating parking garages is a subject of concern to municipalities, tenants, property owners and politicians. Prudent legislative procedures which would ensure reliable repairs that lend themselves to lowcost maintenance and monitoring practices are of interest to all parties. To this end, the Committee addressed five main subject areas and has provided the required advisory documents as Chapters 2 6. Additional issues were raised by the full Committee and the Subcommittees. These issues are not directly related to the mandates, but are believed to be of equal and separate importance, and worthy of inclusion in this document since ultimately most of these issues affect residential affordability. While the Ministry proceeds with specific recommendations regarding parking garages, the Committee asks it to also

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consider the implications of these activities in relation to one other major provincial activity: highrise regeneration. In the case of both parking garages and highrises, repairs are being proposed by municipalities. In some cases, the funds for these repairs are only available from the two senior levels of government.

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In a number of technical areas, the necessary research to ensure that the appropriate materials, products or systems are chosen to provide costeffective rehabilitation is not yet completed. The fundamental issue appears to be, therefore, notwithstanding any legislation that might be enacted or communication programs initiated; what can society, that is, property owners, through the tax system, afford to pay? For instance, the average age of over 50 percent of the province's highrise structures will exceed 20 years by 1990. Considerable funds may soon be needed for their upgrading and subsequent maintenance. Both private sector and public sector organizations will have to assess the factors affecting the service life of these buildings, many of which include structural parking garages. A particular dilemma for Ontario is that over 40 percent of its rental stock, accounting for over 430,000 dwelling units, will be involved in these technical and economic assessments. While some of these units have outdoor slabongrade parking that are unlikely to be affected by the proposed legislation, many other residential highrises with integral structural garages will be directly affected. Accordingly, overall economic assessments must take into account both deteriorating parking garages and other failed subsystems. In addition to parking garage problems, components of these highrise units which may also need to be upgraded are roof decks, envelope systems, windows, doors and associated balconies, and heating/cooling systems. Wiring and plumbing systems may also need evaluation. Most of the buildings have steelreinforced concrete cores. It is expected these cores will be structurally sound abovegrade and will readily lend themselves to renovation. The dominant question is what makes the best economic sense in tackling these renovations? One particular economic problem could be the consequences of rehabilitating roadsalt damaged, steelreinforced concrete parking garages forming the belowgrade sections of many buildings. The value of these buildings could be diminished as rental property if extensive repairs are necessary. The value of the land on which these buildings sit may suggest that demolition and reuse of the property for other purposes might be the best solution (3). Federally funded and directed research has provided information

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about saltdamaged parking garages and the failing envelope systems of highrise buildings. Through other research, we are attempting to understand the livingspace air quality needs of residential highrises once thermally upgraded envelope systems are put in place. We know less about potential freezethaw reactions, alkalireactivity and carbonationinduced corrosion of cladding systems. These three decay processes are timedependent phenomena. They take place over extended periods of time, perhaps over ten to twenty years or more, and can have adverse affects on structural or veneer concretes and masonry.

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Repair choices for parking garages must be made with an understanding of the future worth of the building. Implementation of various upgrading techniques need to be approached with caution by both public and private sector owners. The technical knowledge base about envelope performance is improving rapidly, the technology for new heating/cooling systems is changing while garage repair evaluations are not yet complete. Changing demographics must also be considered. It may place different demands on highrise residential units requiring rehabilitation, subsequently affecting their value. Evaluation criteria for a full range of repair systems (not just materials) need to be developed, including quality control on the jobsite. 1.6.1 Business Potential Notwithstanding its direct mandate to review the stateoftheart and make recommendations regarding repair and maintenance of existing parking garages and to construction of new garages, the Committee believes that these, essentially sitespecific activities, should be considered in the light of provincial, national, and export trade opportunities also. These trade opportunities can build on the research efforts of others but they must ensure that future research is carried out to remove the technical and economic uncertainties, as they currently exist. A successful, coordinated, technical and financial approach to resolving the parking garage issue could be of value in the four trade issues stated previously (1). For instance, the number of parking stalls in the province needs to be estimated. Private sector labour and material suppliers input is needed to assist the province in determining how to repair these garages costeffectively. Estimates for the supply/demand requirements for a 15 year period should be established. Funding mechanisms must be identified for repairs to damaged structures, if the costs of repairs exceed reserve funds, or are not financially sustainable under current tax legislation. The repair of existing structures and the building of new garages offer opportunities for many segments of Ontario industry. For example, the Plastics Industry believes that new

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materials and processes must be considered in both repair and new construction. The continuing use of conventional materials may lead to future problems. Materials should be chosen on the basis of their longterm value in use, not on initial cost alone. The Society of the Plastics Industry and its members have endeavoured to familiarize themselves in a general way with the current problem. Plastics are available for reinforcing steel coatings, deck sealants, long lasting expansion joints and corrosion resistant drains. The Plastics Industry is exploring means whereby its products may be tested in reallife situations. A further potentially valuable method for retarding the rate of corrosion in steelreinforced concrete is the application and use of cathodic protection (CP) systems. CP techniques have been applied for almost 100 years to a wide range of valuable capital structures and equipment. In the last twenty years, these techniques have proven successful on roadway bridges. These CP systems, proven beneficial on bridges, are being promoted for parking garages but technical uncertainties with regard to design and operating criteria need a system of monitoring and maintenance to resolve them. This latter, postinstallation activity of monitoring and maintenance can prove, at times, unexpectedly expensive. Uncontrolled use of this corrosion retarding technique in the wide range of parking properties in Ontario might cause unexpected financial or technical problems for some owners. 1.6.2 Financial Implications Many classes of property owners will be affected by any of the proposed new legislation which, by its nature, cannot be selective. The ability to pay for necessary repairs will vary among these owners which include: Social Housing, Public Housing, NonProfits, Coops, Condominiums, and Municipal and Commercial Parkades. At one end of the economic spectrum, federal, provincial and municipal housing agencies will need to go through extensive budgeting processes to respond financially to the impact of unclear legislation. Ultimately, however, it is expected this group of property owners will be able to pay the cost. At the other end of the economic spectrum are such organizations

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as CIPREC. These property owners believe their parking structures are not a risk in terms of public safety. As sound property managers, they have embarked on an extensive survey of the performance of existing repaired garages in their own portfolios. The prime motivation for CIPREC's activity in this area is economic. It is expected that these property owners will be able to pay for all future repairs, while seeking the best return on their current investment. The Committee recognizes that besides the two groups more able to afford repairs, a third category of owners exists, these are, individual owners of commercial or residential properties, coops, condominiums and nonprofit. The impact of any legislation on these owners deserves special attention. Because of the less organized nature of this category, special attention will also be necessary when structuring the communication strategy and developing costeffective repair criteria.

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The Ontario New Home Warranties Plan Act provides protection against financial loss from major structural defects resulting from any defect in workmanship or materials. If a builder fails to rectify valid claims of major structural defects filed within five years of an owner taking possession of a new home, the New Home Warranty Program administering the Act will correct the defect or pay for the damages out of the Guarantee Fund and revoke the builder's registration. Without registration, a builder is not permitted to build dwelling units for sale. The progressive corrosion of reinforcing steel in concrete parking structures and buildings (owned, for instance, by a condominium corporation) could be claimed as a major structural defect if it is the result of defects in material (concrete not air entrained as specified) or workmanship (concrete cover less than specified). The cost of rectifying this defect would be paid out of the Guarantee Fund. A series of claims of this type might be beyond the limits of the Guarantee Fund. For these reasons, it poses a very real threat to the stability of the shelter industry and warrants consideration by the Ontario Ministry of Housing as a related issue. 1.7 RESEARCH NEEDS Despite the significant economic importance of the parking garage problem, relatively little research has been carried out in this field. The urgency of the need to rehabilitate some deteriorated garages has forced consultants, contractors and owners to carry out repairs with essentially unproven methods. The new CSA Standard S41387 (Durable Parking Structures) specifies design requirements and construction practices for new garages. The specifications reflect the experience and current thinking of the very knowledgeable members of the Standard's Technical Committee but are not yet supported by physical test data and evaluation of the performance of existing garages. Even less information is available for the formulation of repair strategies of deteriorated garages. Accordingly, for saltdamaged parking garages alone, a great need exists for research in a number of areas, including steps to determine the following: cost effectiveness of the various repair methods

20

merit of cathodic protection physical and chemical properties of membranes for good performance when applied in parking garages physical and chemical properties of concrete sealers for good performance when applied in parking garages

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relative merits of repair strategies (major repairs periodically or ongoing intensive maintenance) relative merits of the various types of structural design definition of requirements for climatic conditions in the various regions of Canada effects of the microclimate prevailing in different types of garages development of a standard survey procedure for the evaluation of the condition of garages and the evaluation of the usefulness of tests presently utilized development of new instrumental methods for the evaluation of the condition of garages evaluation of the various types and methods for heating ramps evaluation of the corrosion resistance of drain units. The foregoing list is not in order of priority. A number of the above topics are addressed in a research project sponsored by CIPREC, CMHC, IRC, MOH, and PWC. Definitive results are expected from this study in 1992. However, it is clear that research should be carried out on a much greater scale. In view of the magnitude of the repair cost of the deteriorated garages, the savings to the economy resulting from worthwhile research could be substantial, and the funding of the research be justified and costeffective. Specifically, the Plastics Industry believes that a more definitive economic expression of the magnitude of problems in Ontario and the potential problem in Canada would stimulate additional research and development. In addition, such research would help the building industry's regulatory bodies which administer codes and standards, to understand the need to evaluate new concepts and products in an expeditious manner, and so encourage the invention of new materials and techniques specifically oriented to the construction and maintenance of parking structures. The level of funding for a broadly based program of such research, including support from materials suppliers, property

22

owners and input from at least two levels of government, would probably be in the order of 1 3 percent of the estimated $1 billion plus provincial problem.

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1.8 DATA REPOSITORY Design and performance data on concrete restoration are not well documented. Rehabilitation methods and materials used to remedy deteriorated concrete parking structures vary widely. Experience in this field is not widespread in the engineering community. A central data repository for design and performance information on remedial projects is essential to the evolution of improved cost effective concrete parkade restoration. Indications from the engineering design community, active in concrete rehabilitation, show cooperative support for this concept. 1.9 PUBLIC RESPONSE TO COMMUNICATION STRATEGY One of the Committee's mandates was to ensure public safety in all parking structures. Accordingly, the system of legislation proposed, together with its required inspection and enforcement programs and the related repair and maintenance activities, must all be directed to assure the public of longterm durability. Accordingly, whatever communication program is chosen regarding the awareness and safety of damaged parking garages, care must be taken to ensure that no unwarranted concern is raised particularly in the user public.

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REFERENCES 1."A Strategy for Ontario's Building Industry", Building Industry Strategy Secretariat, Ontario Ministry of Housing, 1986. 2."The Regulatory Reform Program Under The Ontario Building Industry Strategy", Buildings Branch, Ontario Ministry of Housing, 1986. 3."Conservation of Ontario's Highrise Rental Apartment Stock", A Discussion Paper Prepared by Clayton Research Associates Limited, on behalf of Housing Renovation & Energy Conservation Unit of The Ontario Ministry of Municipal Affairs & Housing, May 1984.

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CHAPTER 2 THE DETERIORATION PROBLEM AND INSPECTION TECHNIQUES

1

2.0 THE DETERIORATION PROBLEM AND INSPECTION TECHNIQUES 2.1 INTRODUCTION Corrosion of steel forming structural elements in parking garages is common and is primarily due to the effects of road salt. It is now evident that deterioration of concrete parking garages is occurring due to the rapid corrosion (rusting) of reinforcing steel caused by the progressive accumulation of salt in the concrete. It is now generally accepted that the standards and practices applied until recently in the design, construction and maintenance of these structures are inadequate to ensure their satisfactory service and performance. As a direct consequence, the majority of existing parking structures are subject to rapid and progressive deterioration, which may result in localized and unexpected structural failure unless repairs are carried out. Of particular concern are the roof slabs of underground parking garages. These are often buried beneath paving and landscaping materials that make the top surface of the concrete inaccessible for routine inspection. Localized failures of garage roof slabs become possible due to the progressive corrosion of reinforcing steel and the related delamination of the concrete. 2.2 SCOPE In this chapter, only problems relating to existing buildings are reviewed. Guidelines for the design of new parking structures are provided by CSA Standard S41387 (Durable Parking Structures). 2.2.1 Types of Parking Garages Parking garages may be located both above and below ground. They are constructed from a wide variety of structural systems, with the most common type being castinplace reinforced concrete. The basic structural element is a floor system supported by columns, beams and/or walls of different configurations. The more common types of garage structural systems are: o Reinforced Concrete Flat Slab

2

This type of structure consists of reinforced concrete columns supporting flat slabs that usually have drop panels at each column. It is a common design in buildings where space and height are at a premium.

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o Reinforced Concrete Beam and Slab This system is used to attain longer clear spans and is commonly utilized in the design of underground parking levels of buildings and independent structures. o Post-tensioned Structures Post-tensioning can be used in certain or all elements of structures in order to reduce construction depth and cracking of the members. o Precast Concrete Structures Standard T-beams or slabs are used to form the floors of the parking structure and may be supported by a variety of systems such as precast columns and walls, reinforced concrete columns and walls, or structural steel frames. These designs are used where long spans are required to minimize the number of columns. o Steel Structures Structural steel frames are used to support one or more types of floor systems, and include reinforced concrete, precast concrete slabs or T-beams, or metal deck with composite concrete floor. 2.2.2 The Deterioration Process The concrete component of parking garages, both under and above ground, may be affected by such deterioration processes as sulphate attack, alkali aggregate reaction, or freezing and thawing effects. This damage is generally not structurally significant and any related deterioration is not normally rapid or severe enough to become a substantial factor in the parking garage problem. Such kinds of concrete deterioration are usually due to specific conditions in a particular garage or locality and will not be reviewed in detail. Rapid and progressive structural deterioration of parking garages is mainly caused by corrosion of the reinforcing steel in the concrete, as already mentioned, or of the steel tendons in post-tensioned or pre-tensioned concrete.

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2.3 THE NATURE OF THE CORROSION PROCESS 2.3.1 Corrosion of Steel in Concrete Steel normally corrodes when exposed to moisture and oxygen in the air. Rust (iron oxide), the stable form of iron, is the form in which iron occurs in nature and to which it reverts unless additional measures are taken. Isolation from the environment by painting or coating is one protective measure that may be taken to prevent steel from corroding. This measure is effective when coatings with high dielectric properties are properly applied to steel. Reinforcing steel has been used successfully without the need for special protection because, in the alkaline environment created by the high lime content of concrete, a continuous protective film develops on the steel surface and prevents corrosion. Under such conditions, steel behaves more like a noble, noncorroding metal and is therefore said to have acquired "passivity". This passive, non-corroding state will exist while a high alkaline environment is maintained unless a "depassivator" destroys it. Depassivators break down the passivity or prevent its formation in concrete, consequently eliminating the beneficial effect of alkalinity and creating a condition for corrosion to occur. The chloride ion is a common and effective depassivator. Unfortunately, the chemicals now used as deicing agents on roads are almost all chloridebased, and include sodium and calcium chlorides. The carbonation of lime in concrete also results in the corrosion of reinforcing steel. As carbon dioxide is absorbed from the air, the alkalinity of the environment around the steel is reduced to the point where the passive state of the metal is terminated, thus allowing corrosion to occur. Galvanic corrosion occurs when two or more dissimilar metals in electrical contact are placed in a common environment that contains any moisture and/or dissolved salts. In such circumstances, one metal, the anode, will partly or completely corrode. For this reason, the use of dissimilar metals should be minimized. In parking garage decks, only metals galvanically compatible with reinforcing steel should be embedded in the

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concrete. The use of galvanized steel may accelerate the corrosion of reinforcing steel. Corrosion cells can also be formed between similar metal components if the environments surrounding the two metals are different, e.g. the concentrations of oxygen or other substances are different. Regardless of the source of steel corrosion, the result is deterioration of the reinforced concrete as the bond between the steel and the concrete is broken; furthermore, the build-up of rust leads to the development of stresses and cracking in the surrounding concrete. In its most common form, this deterioration results in the delamination of the concrete slab surface.

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Tendons in post-tensioned concrete structures, if embedded in mortar, represent a case that is merely a variation of the one described for reinforcing steel. Where grease or plastic sheaths surround the tendons, passivity does not necessarily develop and protection is based instead on isolation of the steel from moisture, oxygen and chlorides. Corrosion of tendons and their anchorages will have a most serious effect on the load carrying capacity and serviceability of the structure. In addition, the corrosion of tendons pose a serious hazard to garage users due to the potential for sudden eruption of the failed tendon from the slab. 2.3.2 Factors Affecting the Rate of Corrosion Corrosion of steel in concrete will usually occur when all of the following environmental conditions are present: o Soluble chloride ion concentration exceeds a certain threshold value o Moisture content of the concrete exceeds a certain threshold value o Oxygen is available o Suitable temperature The rate of deterioration depends on various factors. The presence of moisture and oxygen has to be sufficient to sustain the reaction. The rate of corrosion will generally increase with higher amounts of moisture, salts and oxygen in the environment. In practice, installing a waterproof membrane or applying a sealer to the top surface of a concrete slab is, in principle, considered to be beneficial. Good floor drainage provided by sloped surfaces and properly sited drains also lessens the probability of salt and water intrusion into the concrete. Factors governing the rate of delamination in concrete floor and roof slabs following construction are: oThe design and quality of construction of the slabs with regard to: Concrete cover over the top reinforcing steel

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Drainage Porosity of the concrete oThe environmental conditions in which the reinforced concrete exists (see above). During the first few years in the life of a parking structure, no delaminations may occur although moisture and salt are accumulating in the concrete at the location of the top reinforcing steel. To this point in time, passivity of the steel has been maintained. Once passivity is lost, corrosion commences.

8

Even though corrosion continues, no delaminations will occur until the corrosion product on the reinforcing bars creates tensile forces sufficient to exceed the tensile strength of the concrete. Hence, the steel can corrode without visual evidence. Assuming corrosion is not mitigated, delamination will subsequently occur rapidly. Thus delamination of concrete from the top surface of a normally reinforced concrete garage floor or roof slab follows three phases, namely: oDuring an initial period of a few years, there is normally no delamination. oDuring the following few years, there will be rapid delamination. oAfter this period of rapid delamination, a reduction in the rate of further delamination may occur under certain conditions. Delamination of the underside of concrete slabs occurs often, but normally much later than the onset of top surface delamination. As chlorides and moisture permeate from the top of the slab, top surface delamination usually occurs first. Underside delamination begins only when the chloride content around the bottom steel is sufficiently high and the necessary environmental conditions exist (delamination begins only when the passivity of the bottom steel is lost). Frequently, the corrosion initiates along the line of cracks in the concrete through which salt and moisture can easily penetrate. 2.4 REPAIR OF DETERIORATED GARAGES The measures beneficial in lessening the corrosion rate in an existing garage are limited in number. It is often either impractical, uneconomical or ineffective in an existing garage to apply measures which in a new garage that is uncontaminated with salt, yield excellent results. For example, seldom is it feasible to increase the concrete cover over the reinforcing steel, to remove embedded conduits or to replace all of the chloride contaminated concrete. The repair of deteriorated garages requires serious technical considerations and should only be undertaken by competent and

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suitably experienced consultants and contractors. The most common repair and mitigation method (hereinafter referred to as repair) at this time is to locally repair the deteriorated sections of the floor slab and then to install a waterproof membrane on the top surface of the slab to prevent further water and salt penetration into, and through, the floor slab. This repair procedure does not necessarily ensure against further deterioration of the concrete since unrepaired areas of structurally sound concrete may be salt contaminated and prone to deterioration.

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The effects of localized repair on the future performance of parking structures has been the subject of many studies. Some reports suggest that notwithstanding the limitations of a localized repair method incorporating a waterproofing membrane, repairs not only restore the garages but further deterioration, if it takes place, will progress, in the majority of cases, at a much reduced rate. The prospects of success of the repair are greatly enhanced if it is undertaken at early stages of deterioration. Other reports regarding the localized repair (including waterproofing) of the garage floor slabs indicate wide variation in performance of the rehabilitation system with significant additional deterioration occurring over a few years in some cases. Other options for the rehabilitation of garage floors may include one or a combination of the following: the application of cathodic protection to arrest the corrosion of the reinforcing steel, the construction of a concrete overlay on the top surface of the parking floors and replacement of corroded reinforcing bars with new coated bars. In developing a repair strategy, it is important to realize that certain measures reduce the options available for future repairs. For example, a requirement for cathodic protection is electric continuity of the reinforcing steel. Epoxy resin (a nonconductive material) used as an adhesive to repair or line new concrete may minimize the effectiveness of cathodic protection in this isolated area. Alternatively, however, failure to isolate the chloridefree replacement concrete from the surrounding chloride contaminated concrete and from the reinforcing steel by the application of an epoxy resin adhesive may encourage severe localized corrosion of the reinforcing steel located immediately adjacent to the repaired area. Similarly, the application of a sealer on the concrete surface may make it difficult to achieve good adhesion between a waterproofing membrane and the surface of the concrete, should one be installed at a later stage. These observations should not be construed as recommendations for any repairs. They merely emphasize that: 1.Once garage deterioration has passed a certain stage, periodic repairs must be anticipated. 2.Implementation of a specific method of repair may reduce the options available for future repairs.

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Effective rehabilitation of a deteriorated parking garage is a complex project, demanding much experience and knowledge by all those involved. Choice of a method of rehabilitation that will make effective use of resources in extending the service life of the structure must be based on a systematic approach that considers the characteristics of each method available and its effect on the structure's future performance and serviceability. Before a repair program can be instituted, a proper program of inspection, testing and data recording should take place.

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2.5 INSPECTION AND TESTING 2.5.1 Introduction The reasons for periodic inspection of parking garage structures are to detect deficiencies and deterioration, ranging from the need for safety (related to the load carrying capacity of suspended parking floors), to the need for timely information on the condition of the structures to ensure prompt and cost-effective maintenance and repair. This section reviews inspection procedures and testing techniques suitable for assessing the condition of the various components of garages. These range from basic and relatively simple procedures that demand no special expertise, to sophisticated inspection and testing techniques that normally might succeed only when used by the trained staff of a consulting engineer or other specialist. It is not intended here to deal with inspection routines followed in regular planned maintenance work, such as checking the effectiveness of drainage systems, ramp heating or snow removal; nor safety and security procedures essential to the prevention of equipment failure or the premature deterioration of structural elements of a parking garage. Environmental factors within parking garages are more severe in their effects than in most other buildings. In winter, extensively used road salt penetrates the concrete, causing corrosion of reinforcing steel; in addition, extremes of temperature and humidity within many garages tend to promote significant deterioration. For these reasons, maintenance and inspection of components of parking garages should be more rigorous than for other building components. 2.5.2 Structural Deficiencies Structural integrity is of prime concern in evaluating deterioration of garages. If impaired, it must be restored and measures must be instituted to maintain the structure in a safe condition. Structural distress may be defined as a condition where one or more elements of a building are so impaired that the structure's ability to carry its designed load safely cannot be assured.

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Structural distress may develop gradually in a parking garage as a result of corrosion of steel and related delamination of concrete. The distress may also be due to the presence of one or more of the following conditions: oImproper design or poor construction of any components of the structure leading to such deficiencies as: cracking of structural slabs - frequently experienced in the area of column supports.

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cracks in supporting members, in particular shear cracks in beams and supporting brackets or corbels. noticeable and undue deflection of any of the members. The cracking and deflections seen may be an indication of overstress that may be significant and potentially serious. o Thermal movements Most parking garages are subjected to expansion and contraction from temperature changes and these, combined with shrinkage and creep of concrete, can cause considerable distress if provision is not made to accommodate movements resulting from these factors. o Bearing failures Bearings support structural elements and allow thermal movements to take place. Failure of bearings can prevent the structure from acting as intended by the designer and can cause structural distress or failure. o Freezing and thawing Damage to concrete can be caused by freezing and thawing if the concrete is not properly air entrained. o Overloads Loads exceeding design loads occur particularly on upper decks without height restrictions, in landscaped areas where growing vegetation can considerably increase original and intended loads and where impact loads occur due to speed bumps, etc. o Foundation failure Foundation failure can allow differential settlements to occur in the supporting structure and lead to undue stress and cracking of members. o Corrosion of the reinforcing steel Corrosion of the reinforcing steel leads to loss of bond between

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the reinforcement and the concrete; this results in cracking of the concrete cover and impairment of structural integrity.

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o Corrosion of post-tensioning tendons Corrosion of tendons can lead to a reduced load carrying capacity of the structure and ultimately to collapse of the affected elements. It can also pose an immediate threat to garage users due to the potential for sudden failure. o Joint failure Joints are necessary to accommodate thermal movements and, if not properly designed and installed, can fail. Through the failed joint, salt-laden water can invade the concrete, a condition that may lead to corrosion. 2.5.3 Structural Components Components of a parking garage normally inspected and tested when the structure is being assessed for repair are: 1. Foundations Since these are commonly buried, they are not normally of significant concern. 2. Columns Supporting elements often exposed to corrosive materials and so in need of protection. 3. Walls Form barriers to external forces either above or below ground elevation and may be subject to corrosive materials from within and water leakage from outside. 4. Beams Horizontal supporting elements for slabs. 5. Slabs Members supporting vehicular or landscape loads (as roof slabs). 6. Brackets and corbels

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Often attached to columns and walls to support beams or slabs.

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2.5.4 Inspection and Testing Procedures Inspection and testing procedures may be divided into two categories: 1.Simple methods forming part of a "walk through" inspection, often carried out by maintenance or management personnel reporting to the owner, that could identify and define certain problems. Visual observation is appropriate as part of a "walk-through" inspection. 2.Detailed methods undertaken by a suitably experienced engineer, usually retained by the owner to prepare recommendations for rehabilitation of the garage. 2.6 SUMMARY OF COMMONLY USED INSPECTION PROCEDURES Table 2.1 lists the common inspection and testing methods used to assess the condition of components forming a parking garage. These procedures should always be accompanied by an inspection of the entire structure and the preparation of records in the form of photographs and drawings detailing the visual appearance of the structure at the time of inspection. 2.6.1 Other Considerations 1.In general, other reinforced concrete components in a parking garage such as concrete columns, walls, stairs, elevator shafts, and precast cladding are less affected by the damaging effects of salt and water than level floor slabs used for parking. Similar deficiencies do sometimes occur however, and the test methods noted above may be applied, for the most part, to all reinforced concrete components in the structure. 2.In some parking garages, extensive use is made of such steel structural components as floor beams, columns, and pan systems on the underside of slabs. The most common deficiencies are: Corrosion aggravated by wet conditions and chlorides. Cracking in the structure due to fatigue or poor fabrication. Distorted steel components due to overloading or collision damage.

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Pitting corrosion can cause a serious reduction in the load carrying capacity of steel components and can lead to fatigue cracking. Cracking of any kind in steel components can have the most serious consequences on the serviceability of the structure, as can bent, twisted or distorted components.

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3.Under most deterioration conditions, straightforward inspection and testing techniques are inappropriate for parking structure elements using post tensioning steel tendons as part of concrete construction. A visual "walk-through" inspection is unlikely to reveal deficiencies in the post tensioning system since the tendons and anchors are for the most part hidden. Any evidence of corrosion, cracking, or delaminations in the area of anchors or "burst-thru" of tendons on the top or underside of the slab, indicates most serious consequences in the load carrying capacity and serviceability of the structure. 4.Delaminations in concrete and debonding of waterproofing system layers can be detected by striking the surface and noting a change in the sound emitted. The chain drag method is more suitable for large areas of top surface. As the chain is moved from side to side along the surface, a change in the normal ringing sound to a duller sound would normally indicate a delaminated concrete area or a debonded membrane area. 2.6.2 Detailed and Specialized Inspection and Testing Techniques A detailed condition survey of the parking structure, using specialized inspection and testing techniques, is essential in the process of determining the extent of deterioration, the effect of any deterioration on the present and the future serviceability of the structure, the optimum strategy for maintenance and rehabilitation of the parking garage and the various technical and financial issues related to rehabilitation. A detailed condition survey also has special importance for systems such as post-tensioned concrete where straightforward inspection and testing are unlikely to identify any deficiencies. Recording of all technical test data derived from the condition survey is important. Subsequent repair strategy will be based on this technical data, which may also be needed to resolve possible disputes. Detailed condition surveys must be carried out by technical staff experienced in such work, normally consulting engineers. A number of guidelines (some written for highway structures) are available and would be useful in the planning and carrying out of detailed condition surveys. These references are listed in

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Appendix 2A. 2.7 ILLUSTRATIONS Photographic illustrations of typical failure modes in steelreinforced concrete structures and current investigative techniques are shown on pages 32 39.

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TABLE 2.1 SIMPLE INSPECTION & TESTING PROCEDURES +)))))))))))))))))))))))))0)))))))))))))))))))))))))))))))0)))))))))))))))))))))))0)))))))))))))))))))))))))))))))))))))), * Component * Deficiency * Test Method * Likely Consequence of Deficiency * /)))))))))))))))))))))))))3)))))))))))))))))))))))))))))))3)))))))))))))))))))))))3))))))))))))))))))))))))))))))))))))))1 *1. Top surface of roof * Speed bump damage. * Visual * Localized structural distress of * *slab supporting over- * * * the roof slab due to impact loads * *burden materials (under- * * * from vehicle wheels. * *ground parking garage). * * * * * * * * Distress could result in the * * * * * development of cracks visible on * * * * * underside of the roof slab. * * * * * * * * Excess depth of overburden * Test pit and reference* Structural distress of the roof * * * materials. * to design drawings. * slab. * * * * * * * * * * Distress could result in the * * * * * development of cracks visible on * * * * * the underside of the roof slab. * * * * * * * * Localized failure of the * Test pit and visual * 1. Water penetration through the * * * membrane. * observation. * roof slab. * * * * * 2. Accumulation of salt in the * * * * * concrete under paved areas. * * * * * 3. Corrosion of the reinforcing * * * * * steel and delamination of the * * * * * concrete. * * * * * * * * Unbonded membrane. * Test pit and visual * Combined with localized failure of * * * * observation. * the membrane, conditions exist for:* * * * * 1. Water penetration through the * * * * * roof slab. * * * * * 2. Accumulation of salt in the * * * * * concrete under paved area. * * * * * * * * Corroded reinforcing steel and* Removal of overburden * Local reduction in load carrying * * * delaminated concrete. * materials from small * capacity of the roof slab. * * * * area of roof slab. * * * * * * * * * * Visual observations * * * * * with sounding (1) * * * * * hammer, steel rod or * * * * * chain. * * .)))))))))))))))))))))))))2)))))))))))))))))))))))))))))))2)))))))))))))))))))))))2))))))))))))))))))))))))))))))))))))))-

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TABLE 2.1 (cont'd) SIMPLE INSPECTION & TESTING PROCEDURES +)))))))))))))))))))))))))0)))))))))))))))))))))))))))))))0)))))))))))))))))))))))0)))))))))))))))))))))))))))))))))))))), * Component * Deficiency * Test Method * Likely Consequence of Deficiency * /)))))))))))))))))))))))))3)))))))))))))))))))))))))))))))3)))))))))))))))))))))))3))))))))))))))))))))))))))))))))))))))1 *2. Underside of: * Wet or damp areas. * Visual * Deteriorated concrete in slab. * *Roof Slab, Suspended * * * Deteriorated joints. * *Parking Levels, Ramps. * * * Failure of waterproofing membrane. * * * * * Failure of drainage system. * * * * * * * * Continuous, relatively * Visual plus magnify- * Leakage of water and salt * * * straight, narrow or hairline * ing glass and ruler/ * solutions. Corrosion of reinforc- * * * cracks in the concrete (less * scale. * ing steel. * * * than 0.3 mm wide). * * * * * * * * * * Continuous, relatively * Visual plus magnify- * Leakage of water and salt * * * straight, medium or wide * ing glass and ruler/ * solutions. Corrosion of reinforc- * * * cracks in the concrete (more * scale. * ing steel. If this deficiency is * * * than 0.3 wide) * * accompanied by pronounced deflect- * * * * * ion in concrete slab then load * * * * * capacity of floor system may be * * * * * significantly reduced. * * * * * * * * Rust stains. * Visual * Corrosion of reinforcing steel or * * * * * other metals embedded in the * * * * * concrete. * * * * * * * * Delaminated concrete (concrete* Visual with sounding * Corrosion of reinforcing steel or * * * layer may have dropped off * (1) using hammer * other metals embedded in the * * * exposing fractured face in * or steel rod. * concrete. * * * concrete and reinforcing * * * * * steel). * * Large area of delaminated concrete * * * * * may significantly reduce the load * * * * * capacity of the floor. * * * * * * .)))))))))))))))))))))))))2)))))))))))))))))))))))))))))))2)))))))))))))))))))))))2))))))))))))))))))))))))))))))))))))))-

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TABLE 2.1 (cont'd) SIMPLE INSPECTION & TESTING PROCEDURES +)))))))))))))))))))))))))0)))))))))))))))))))))))))))))))0)))))))))))))))))))))))0)))))))))))))))))))))))))))))))))))))), * Component * Deficiency * Test Method * Likely Consequence of Deficiency * /)))))))))))))))))))))))))3)))))))))))))))))))))))))))))))3)))))))))))))))))))))))3))))))))))))))))))))))))))))))))))))))1 *3. Top Surface of: * Delaminated concrete (concrete* Visual with sounding * Corrosion of reinforcing steel. * *Suspended Parking Levels * layer may have been removed * (1) using hammer, * * *Ramps, Floor on Grade, * exposing fractured face in * steel rod or chain. * Potholing of concrete surface. * *(Exposed Concrete * concrete and reinforcing * * * *Surface). * steel). * * Large areas of delaminated concrete* * * * * may significantly reduce the load * * * * * capacity of the floor. * * * * * * * * Scaled concrete. * Visual * Continued deterioration of concrete* * * * * slab from top surface downwards. * * * * * * * * Continuous, relatively * Visual plus magnify- * Leakage of water and salt * * * straight, narrow or hairline * ing glass and ruler/ * solutions. Corrosion of reinforc- * * * cracks in the concrete (less * scale. * ing steel. * * * than 0.3 mm wide). * * * * * * * * * * * * If this deficiency is accompanied * * * * * by pronounced deflection in * * * * * concrete slab then load capacity * * * * * of floor system may be signifi- * * * * * cantly reduced. * * * * * * * * Continuous, relatively * Visual plus magnify- * Leakage of water and salt * * * straight, medium or wide * ing glass and ruler/ * solutions. Corrosion of reinforc- * * * cracks in the concrete (more * scale. * ing steel. If this deficiency is * * * than 0.3 mm wide). * * accompanied by pronounced deflect- * * * * * ion in concrete slab then load * * * * * capacity of floor system may be * * * * * significantly reduced. * * * * * * * * * * * .)))))))))))))))))))))))))2)))))))))))))))))))))))))))))))2)))))))))))))))))))))))2))))))))))))))))))))))))))))))))))))))-

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TABLE 2.1 (cont'd) SIMPLE INSPECTION & TESTING PROCEDURES +)))))))))))))))))))))))))0)))))))))))))))))))))))))))))))0)))))))))))))))))))))))0)))))))))))))))))))))))))))))))))))))), * Component * Deficiency * Test Method * Likely Consequence of Deficiency * /)))))))))))))))))))))))))3)))))))))))))))))))))))))))))))3)))))))))))))))))))))))3))))))))))))))))))))))))))))))))))))))1 *4. Top surface of: * Debonding of membrane. * Visual with sound- * Local penetration of water and * *Suspended Parking Levels,* * ings (1) * salt into concrete. * *Floor on Grade. (Concrete* * * * *surface covered with a * * * Cracking and disintegration of * *waterproofing membrane * * * membrane. * *plus a wearing course). * * * * * * * * * * * Blisters and blow-ups in * Visual with sound- * Failure of membrane. Corrosion of * * * membrane which may or may * ings (1) * reinforcing steel. Delaminated * * * not be accompanied by * * concrete. * * * obvious delaminated concrete.* * * * * * * * * * Cracks in membrane. * Visual with sound- * Local penetration of water and salt* * * * ings * into concrete. If this deficiency * * * * * is a reflective crack from the * * * * * concrete slab leakage of water and * * * * * salt solutions will result. * * * * * * * * Deformation of wearing course* Visual * Disintegration of wearing course * * * over membrane. * * and membrane. * * * * * * * * Loss of wearing course. * Visual * Disintegration of membrane. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * .)))))))))))))))))))))))))2)))))))))))))))))))))))))))))))2)))))))))))))))))))))))2))))))))))))))))))))))))))))))))))))))-

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FIGURE 2.1 Localized collapse of garage roof slab.

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FIGURE 2.2 Surface delamination of floor slab. FIGURE 2.3 Surface scaling of floor slab due to freezing and thawing.

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FIGURE 2.4 Surface delamination of floor slab after removal of loose concrete.

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FIGURE 2.5 Delamination of column.

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FIGURE 2.6 Deterioration of garage exterior wall. FIGURE 2.7

31

Delamination of beam.

32

FIGURE 2.8 "Chain Drag" Identifying delaminated areas in top surface of a floor slab.

33

FIGURE 2.9 Testing compressive strength of concrete sample removed from a floor slab. FIGURE 2.10 Removing sample of concrete from a floor slab with a core drill.

34

FIGURE 2.11 Testing repaired floor slab to determine the adhesion between the floor slab concrete and the replacement concrete.

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APPENDIX 2A U.S. Sources 1. "Detecting Defects and Deterioration in Highway Structures". NCHRP Report #118, July 1985 Transportation Research Board National Research Council Washington, D.C. 2. "Guide for Making a Condition Survey of Concrete in Service". ACI Committee 201 Report 201, 1R-68 (Revised 1984) American Concrete Institute Detroit, Michigan. 3. "State-of-the-Art Report on Parking Structures" ACI Committee Report ACI-362R-85 American Concrete Institute Detroit, Michigan. Canadian Sources 4. "Bridge Deck Rehabilitation Manual, Part One: Condition Surveys", 1983 Ontario Ministry of Transportation and Communications Downsview, Ontario. 5. "Repair Techniques for Concrete Bridge Components", 1986 Roads and Transportation Association of Canada Ottawa, Ontario. 6. "Condition Survey", Total Building Performance Evaluation Public Works Canada, Architectural & Building Sciences October, 1986.

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CHAPTER 3 REPAIR METHODS

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3.0 REPAIR METHODS 3.1 INTRODUCTION From measurements of the extent of delamination and active corrosion that are sometimes coupled with load tests, reasonable judgement can be made about the present safety and serviceability of a garage. Judgement may also be made, on the basis of historical data on similar structures, about the probable rate of deterioration. There are, however, wide variations between conditions within a garage which cannot be readily explained or predicted. Predictions will therefore depend greatly upon the experience and skill of the investigating engineer. Before deciding on the need for repair, and the type and extent required, it is necessary to consider the safety and the long-term cost-effectiveness of the methods to be chosen. Fortunately, very few cases of structural failure in parking structures have occurred in Ontario. Top surfaces of garage slabs will often become so broken up that continued use dictates that some remedial action is taken before loss of structural strength becomes dangerous. Owners, municipalities, and engineers have generally ensured that some repairs are carried out before a structure is significantly weakened. However, there has only been very limited scientific assessment of the sustained effectiveness of the various repair methods adopted. The more experience is accumulated, the more uneven results are found to be, and less assurance is felt about the effectiveness of treatment methods thought to represent "state-of-the-art". There is no simple answer to any one problem, and, since each parking structure usually has several different conditions of deterioration, prudent and cost-effective treatment demands resolution of the many interlocking technical and economic considerations.

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3.2 SAFETY Safety must be the primary repair consideration. An experienced structural engineer can analyze a parking structure, making pertinent assumptions about the reduced effectiveness of corroded reinforcement, and can carry out load tests, as laid down in the Ontario Building Code, to determine the fitness of a structure to carry a stipulated load. The analysis depends on accuracy in judging reinforcement loss, and a prudent engineer will err on the side of caution. Load tests can only provide results for limited areas at specific times. The areas prudently selected for load tests would be those that were judged to be severely weakened, based on visual inspection or other tests. With proper engineering judgement, this approach is reasonable in assessing the safety of normally reinforced concrete structures. It could be less satisfactory as a method of assessing the safety of some pre-stressed structures where loss of strength can develop more suddenly and dangerously. A load test cannot determine how long a structure will remain adequately safe, but it can be used to justify the continued use of a garage, which appears to be severely weakened, while remedial work is being devised. It may also be useful in verifying how effective a repair technique has proved in restoring structural adequacy. 3.3ECONOMIC CONSIDERATIONS When selecting an appropriate repair strategy, all factors should be carefully analyzed to provide a balanced solution to the repair problem in terms of cost, physical compatibility and durability or performance. The primary economic objective in any repair assessment is to make comparisons among the several technical alternatives available before investing repair dollars. A rational comparison of the alternatives will assist in ensuring that the method finally selected will provide optimal return for the repair funds available. There would appear to be little benefit in carrying out a complete structural repair without initiating suitable surface treatment to provide the necessary protection during normal daily operations. Life cycle costing studies will be used in these analyses. When setting out the repair alternatives, care must be taken not to give undue weight to one alternative because of personal preferences. All alternatives must be examined in

3

equal detail; failure to do so will lead to a situation where comparisons are not based upon equivalent premises and the economic outcome could be unreliable. One other economic area which should be examined is the area of taxation and its implications for the garage owner. In the case of major real estate companies, capital cost allowances are available to offset depreciation of the structure. In addition, repair costs that are incurred during the normal course of operations are fully deductible against revenues. Under current legislation, there is no incentive for the developer to construct high risk areas of a structure to much higher standards that might reduce the risk of deterioration.

4

Life cycle cost (LCC) studies will show that in many instances the developer is further ahead, from a financial viewpoint, if he constructs the garage area to the established code and accepts a major repair after five years. He is able to offset repair costs against revenues as a single expense and recover any other losses from tenants in the form of increased rental revenues. It may, however, be harder to find tenants for buildings under frequent repair. Taxation option is not available to condominium owners, who must therefore consider differently the many technical/cost repair options. 3.4SUMMARY OF REPAIR METHODS Repair methods which have been used include: 1.Removal of all delaminated concrete, reparation with patches, and the application of surface protection (or cathodic protection). 2.Removal either of all contaminated concrete or of all concrete in areas of high negative half-cell readings, replacement with new concrete, usually with the application of surface protection. 3.Removal of delaminated or all contaminated concrete, and application of a new overlay, such as glass-fibre reinforced concrete. 4.Repair of deteriorated concrete, surface application of top surface protection to minimize moisture penetration and leakage, and application of a cathodic protection system on the underside or the top surface of the slab. See Appendix 3A for a summary statement on the role of cathodic protection. 5.Routing out of cracks and sealing from the top surface, or injecting from below. 6.Total slab removal or the removal of the total top layer of concrete and reinforcement and replacement, using quality-controlled concrete, epoxy-coated rebars and some type of surface protection. There are many variations within the first four methods listed. Generally, delaminated concrete is removed completely; frequently any replaced reinforcing bars are epoxy-coated; sometimes an epoxy bonding agent is used for adhesion of the

5

replacement patch and to provide some electrical isolation; sometimes special additives to reduce permeability and/or conductivity are introduced into the patch concrete. Many surface treatments are available, both sealers and membranes, all with different characteristics, assets, and problems. Various treatments have been used when bottom bars in slabs are corroding, and when column bars are corroding and causing delamination.

6

Experience is accumulating among owners, consultants and contractors, on the performance, over time, of many of the cited treatments, and combinations of such treatments. The benefit of this experience should be sought whenever accessible in deciding on treatment methods for any deteriorated garage. Once methods offering the most reasonable chance of meeting the owner's needs have been identified, consideration must be given to initial repair costs, costs due to disruption of use during the remedial work, and costs of anticipated maintenance and repair. The timing of work should also to be studied, measuring the cost-benefits of delay against projected increase in deterioration that will occur meanwhile. A decision on the most appropriate repair method involves consideration of safety, serviceability, interference in use during repair, as well as short-term and long-term costs. An experienced consultant can provide advice to owners, building managers, municipal authorities and others involved so that, through informed discussion, the most appropriate treatment(s) for each garage can be selected. 3.5 DECISION CRITERIA The decision factors to be considered in evaluating different repair solutions include: 1. Public Safety Considerations 2. Intended Remaining Service Life 3. Life Cycle Costs of Opinions 4. Cash Flow Limitations 5. Any Proposed Change in Use A graphical depiction of the decision matrix faced by owners is attached as Figure 3.1 (Parking Structure Repair Matrix). Extracts from this figure are shown in Table 3.1. This Table does not include construction details required in the design of repair solutions for a parking structure (ie. joints, drainage, utilities, etc.). The initial and maintenance costs vary for different repair solutions. Solutions with higher initial costs may be beneficial in the long term (because of lower maintenance

7

costs); however, they may not be feasible because of cash flow limitations. On the other hand, some solutions may provide very economical alternatives, however these alternatives carry higher maintenance costs. 3.6EVALUATION OF ADVICE So far, no peer-reviewed data on the in-service performance of repair systems and materials, on an extensive scale or over long duration, have been published. There are no national standards that address the problems of repairing parking structures, and until more reliable historical data are generally available, it is unlikely that such standards could be usefully defined. For the moment, reliance must be placed on the experience and judgement of the individual or organization involved in the assessment and repair of the parking garage. 3.7 CONSULTING ENGINEERING SERVICES Correct diagnosis of the types and extent of deterioration is essential. For procedures, refer to the Sub-committee document on "The Deterioration Problem and Inspection Techniques". It is important that repair methods be used that are appropriate to the design of the structure in question, the environment to which it is subjected, and the service life and functions required by the owner. The services described in the previous two paragraphs must be provided by a consulting engineer, with the appropriate structural and repair expertise and experience. Names of suitable firms may be obtained from: The Association of Professional Engineers of Ontario 1155 Yonge Street Suite 101 Toronto, Ontario M4T 2Y5 Telephone Number: (416) 961-1100 The Consulting Engineers of Ontario 86 Overlea Boulevard

8

Suite 403 Toronto, Ontario M4H 1C6 Telephone Number: (416) 425-8027 It is recommended that an owner should obtain and review the following information from a consulting engineer before authorizing his appointment: 1. Similar work carried out in the past. 2. Staff organization, qualifications, experience and numbers. 3. References. 4. Technical committee involvement. 5. Structural knowledge. 6. Published work. 7. Range of methods and materials involved. 8. Resources. 3.8 REPAIR CONTRACTORS There is an association of repair contractors in Ontario at the following address: Concrete Restoration Association of Ontario 1 Sparks Avenue Willowdale, Ontario M2H 2W1 Telephone Number: (416) 499-4000 This association has a standard warranty which it recommends and will make available to owners. It will also provide information on commercial practice and fair contract procedures. It is recommended that an owner or his consultants obtain and review the following information from a repair contractor before authorizing his appointment: 1. Similar work carried out in the past. 2. Staff organization, qualifications, experience and numbers. 3. References. 4. Corporate connections. 5. Technical committee involvement. 6. Range of methods and materials involved. 7. Resources. 8. Bonding capability.

9

9. Proportions and types of work done by main contractor. 10. Proportions and types of work done by sub-contractor. 3.9EDUCATION Several organizations hold, or have held, seminars related to parking structure restoration. These are of value to owners, consultants and contractors. Foremost is the American Concrete Institute, with some relevant seminars to be held each year. The address of the American Concrete Institute, for details of educational seminars and documents, is as follows: American Concrete Institute P.O. Box 19150 22400 West Seven Mile Road Detroit, Michigan U.S.A. 48219 Telephone Number: (313) 532-2600 APPENDIX 3A A Summary on the Role of Cathodic Protection (CP) of Reinforcing Steel in Parking Garages Cathodic protection, a well developed and extensively used electrochemical technique for controlling corrosion of steel structures in a wide variety of aqueous environments, has been proven over the last decade by numerous government research groups to be equally effective on reinforcing steel. Specific development of cathodic protection systems for reinforced concrete structures has been rapid since it was initially tried in the early '70's. The most common type of cathodic protection system for parking garages consists of wire primary anodes embedded in a conductive coating that is applied, after suitable surface preparation, to the soffit side of the reinforced slab. The life of the system is directly proportional to the coating thickness which is typically 16 mils.

10

The primary advantage of cathodic protection over the more common restoration methods is that corrosion can be halted thereby minimizing the need for future restoration work as long as the system is continually operating. Remote monitoring can be incorporated to ensure that the system remains operational thereby extending the useful life of the parking garage. The installed cost of a cathodic protection system is marginally greater than the cost of a high quality membrane; however, surface protection is generally required in conjunction with the CP System. Operating costs are small since the electrical power requirements are in the order of .01 watts per square foot surface area. There is no performance history or lifespan data published for these systems. REFERENCES 1.Robinson, R.C., Cathodic Protection of Steel in Concrete, ACI Publication, SP49, Corrosion of Metal in Concrete, First Printing, June 1975. 2.Slater, John E., Corrosion of Metals in Association with Concrete, American Society for Testing and Materials, STP 818, December 1983. 3.Cathodic Protection of Concrete Bridge Structures, NCHRP Project 1219, National Cooperative Highway Research Program, September 1980. 4.Ward, P.M., Cathodic Protection: A User's Perspective, American Society for Testing and Materials, STP 629, June 1977, pp. 14.

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APPENDIX 3B Publications on Parking Structure Repair 1.ACI Committee 222 "Corrosion of Metals in Concrete", ACI Journal, January-February 1986, pages 3 to 32. 2.ACI Committee 362 "State-of-the-Art Report on Parking Structures", ACI Journal, July-August 1985, pages 544 to 578. 3."Back-To-The-Basics Repair of Concrete", Seminar Course Manual, SCM-13 (86), ACI, 1986. 4. "Parking Structures" ACI Compilation No. 3, C-3, 1980. 5. "Design of Concrete Parking Structures", ACI, SCM 12-86, 1986. 6."Concrete Repair Restoration", ACI Compilation No. 5, C-5, 1986. 7. "Structural Repair - Corrosion Damage and Control", ACI, SCM 8-85, 1985. 8."Interim Guidelines, Investigation, Repairs, Design and Construction of Parking Structures", ACI - Ontario Chapter, August 1981. 9."Deterioration of Parking Structures: Extent, Causes, and Repair Considerations", CMHC, 1987. Sources: 1 - 7 AMERICAN CONCRETE INSTITUTE P.O. Box 19150 22400 West Seven Mile Road Detroit, Michigan, U.S.A. 48219 8 AMERICAN CONCRETE INSTITUTE - ONTARIO CHAPTER 365 Bloor Street East Suite 1402 Toronto, Ontario M4W 3L4

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9 CANADA MORTGAGE AND HOUSING CORPORATION 682 Montreal Road Ottawa, Ontario K1A 0P7

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TABLE 3.1* PARKING STRUCTURE REPAIR MATRIX - EXTRACTS FROM FIGURE 3.1 +))))))))))))))))))))))))))))))))0)))))))))0))))))))))))))))))))))))0))))))))))))))))))))), * * * * * * Level of Repair/Deterioration *Solution * Replacement Material * Mitigation Method * * * * * * /))))))))))))))))))))))))))))))))3)))))))))3))))))))))))))))))))))))3)))))))))))))))))))))1 * * * * * * I. Total Replacement * 1 * Compatible Concrete + * Waterproofing System* * * * Epoxy-Coated Rebars * * * * * * * * * 2 * Compatible Concrete + * Sealer * * * * Epoxy-Coated Rebars * * * * * * * * * 3 * Low Chloride Permeable* Concrete Overlay * * * * Concrete + * - Silica Fume * * * * Epoxy-Coated Rebars * - Latex Modified * * * * * - Iowa Overlay * * * * * - Polymer Modified * * * * * - Fibre Modified * * * * * * * * 4 * Compatible Concrete * Cathodic Protection * * * * * + Sealer * * * * * * G44444444444444444444444444444444P444444444P444444444444444444444444P444444444444444444444I * * * * * * II. Remove All Contaminated * 1 * Compatible Concrete + * Waterproofing System* * Concrete * * Epoxy Coated Rebars * * * * * * * * * 2 * Compatible Concrete + * Sealer * * * * Epoxy-Coated Rebars * * * * * * * * * 3 * Low Chloride Permeable* Concrete Overlay * * * * Concrete + * - Silica Fume * * * * Epoxy-Coated Rebars * - Latex Modified * * * * * - Iowa Overlay * * * * * - Polymer Modified * * * * * - Fibre Modified *

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* * * * * * * 4 * Compatible Concrete * Cathodic Protection * * * * * + Sealer * * * * * * * * * * * B44444444444444444444444444444444N444444444N444444444444444444444444N444444444444444444444A

15

* * * * * * * * * G44444444444444444444444444444444P444444444P444444444444444444444444P444444444444444444444I * * * * * * III. Remove All Concrete * 1 * Compatible Concrete + * Waterproofing System* * to Below Top Steel * * Epoxy-Coated Rebars * * * * * * * * * 2 * Compatible Concrete + * Sealer * * * * Epoxy-Coated Rebars * * * * * * * * * 3 * Low Chloride Permeable* Concrete Overlay * * * * Concrete + * - Silica Fume * * * * Epoxy-Coated Rebars * - Latex Modified * * * * * - Iowa Overlay * * * * * - Polymer Modified * * * * * - Fibre Modified * * * * * * * * 4 * Compatible Concrete * Cathodic Protection * * * * * + Sealer * * * * * * .))))))))))))))))))))))))))))))))2)))))))))2))))))))))))))))))))))))2)))))))))))))))))))))-

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TABLE 3.1* (cont'd) PARKING STRUCTURE REPAIR MATRIX - EXTRACTS FROM FIGURE 3.1 +))))))))))))))))))))))))))))))))0)))))))))0))))))))))))))))))))))))0))))))))))))))))))))), * * * * * * Level of Repair/Deterioration *Solution * Replacement Material * Mitigation Method * * * * * * /))))))))))))))))))))))))))))))))3)))))))))3))))))))))))))))))))))))3)))))))))))))))))))))1 * * * * * * IV. Repair Delaminations Only * 1 * Compatible Concrete * Waterproofing System* * * * * * * * 2 * Compatible Concrete * Sealer * * * * * * * * 3 * Low Chloride Permeable* Concrete Overlay * * * * Concrete * - Silica Fume * * * * * - Latex Modified * * * * * - Iowa Overlay * * * * * - Polymer Modified * * * * * - Fibre Modified * * * * * * * * 4 * Compatible Concrete * Cathodic Protection * * * * * + Sealer * * * * * * G44444444444444444444444444444444P444444444P444444444444444444444444P444444444444444444444I * * * * * * V. Repair Cracks Only * 1 * N/A * Waterproofing System* * * * * * * * 2 * N/A * Sealer * * * * * * * * 3 * N/A * Cathodic Protection * * * * * * * * * * * G44444444444444444444444444444444P444444444P444444444444444444444444P444444444444444444444I * * * * * * VI. No Repairs - Monitor * 1 * N/A * N/A * * Structural Conditions * * * * * * * * * .))))))))))))))))))))))))))))))))2)))))))))2))))))))))))))))))))))))2)))))))))))))))))))))- *

This Table does not include construction details required in the design of repair solutions for a parking structure (ie. joints, drainage, utilities, etc.).

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18

CHAPTER 4 MAINTENANCE AND MONITORING PROCEDURES

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4.0 MAINTENANCE AND MONITORING PROCEDURES 4.1INTRODUCTION In this chapter, only those aspects of identifying, maintaining and monitoring related to the prevention of premature deterioration of the structure are included in a general manner for both unrepaired and repaired garages, types of structures, indoor or exposed environment. For other building elements, Reference 1 in Appendix 4A should be consulted. The following definitions are provided: IDENTIFYING: Before you can monitor a condition and/or maintain it, you first have to know what to look for. MONITORING: Refers to a scheduled routine of periodic inspection and recorded observations of the condition and physical appearance of the parking garage. MAINTENANCE: Refers to all tasks required to maintain the structure at a satisfactory level of service and to prevent serious deterioration of the parking slab and supporting members, which might result, in an extreme case, in partial structural collapse. The primary area of concern is the suspended floor slab in garages. Severity of exposure conditions of parking garages may vary with location, temperature (heated or unheated), levels of moisture and humidity and quantities of road salt used by municipalities. In addition to exposure conditions, the amount of maintenance and monitoring required may depend on materials, methods and design details in the construction or repair of the garage in question. The history of parking garages is relatively short and of repaired garages even shorter, incorporating materials and technologies that have yet to stand the test of time. Accordingly, a conservative approach to maintenance and to monitoring will protect the investment in the capital cost of construction and the additional costs of required repairs while also ensuring that the integrity of the structure is maintained and that public safety is protected. Effective maintenance can extend the useful life of the parking structure.

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4.2SCOPE 4.2.1 Structure Type Before identifying maintenance problems in a structure, it is necessary to identify, in general terms, what type of structure one is dealing with. This aspect is important when trying to assess the relevance of various problems, since a maintenance problem that may be minor in one type of structure may prove major in another. 4.2.1.1 Castinplace Reinforced Concrete The majority of structures in Ontario, particularly those underground, are of cast-in-place reinforced concrete. There are many sub-categories of this type of structure such as plate slab, flat slab and waffle slab. If the sub-category is known, it must be recorded. 4.2.1.2 Posttensioned Post-tensioned structures are constructed of cast-in-place concrete which is stressed after the concrete has gained strength. Here, steel wires of tendons may or may not be bonded to the concrete. 4.2.1.3 Pretensioned Pre-tensioned structures are precast with previously stressed steel wires embedded and bonded in the concrete. When the concrete is hardened the externally applied stressing force is released, which results in stress being applied to the member. Pre-tensioned structures usually have a continuous cast-in-place concrete topping. 4.2.1.4 Steel Steel structures are constructed of field-connected steel columns and beams with a cast-in-place concrete floor slab. 4.2.2Summary of Problems 4.2.2.1 Drainage

3

Inadequate slopes to drains or clogged drains subject the slab to prolonged saturation, resulting in scaling, delamination, spalling or leakage. Ice formed by ponding can be a safety hazard.

4

4.2.2.2 Cracking Cracking of concrete members, floors, roofs, walls, columns or beams can be caused by many factors, but the cracking itself is not necessarily detrimental to the structure. The moisture and salt that cracking allows to penetrate the slab, however, is potentially detrimental. Cracks that are wide and occur in patterns or in increasing size and frequency or length may indicate a serious structural problem. Cracks in post-tensioned or pre-tensioned structures may be more significant than in those of cast-in-place reinforced concrete. All suspect cracking should be referred to a professional structural engineer. 4.2.2.3 Scaling Scaling is a flaking or disintegration of the top surface of a concrete slab. Concrete scaling is caused by freeze-thaw action on wet concrete or prolonged periods of saturation, resulting from ponding. Eventually the scaling penetrates deeper into the concrete, exposing the aggregate. 4.2.2.4 Spalling Spalling can occur on the surface of any concrete element, but is most prevalent on the top surface of floor slabs. In parking structures, spalling is usually caused by a fracture plane or "delamination" at the level of the reinforcing steel, caused by salt-induced corrosion of the steel. Cracking of concrete slabs can allow access of moisture and salt to the underside of slabs, again resulting in soffit delamination and spalling. This phenomenon can occur wherever there is a source of water and salt, such as at the base of columns and walls and along support edges of leaking expansion joints. Spalled, but not fallen, concrete pieces on elevated members are a safety hazard and should be removed. 4.2.2.5 Leaking, Leaching, Rust Stains Water leaking through concrete elements can cause corrosion of steel members, resulting in rust staining of concrete surfaces, or leaching of cement constituents to cause white film or stalactites on slab soffits. 4.2.2.6 Expansion Joints Expansion joints are specific discontinuities set in concrete

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slabs to permit relative movements to take place. Joints should be surveyed from their readily accessible top side to identify areas of sealant failure or adjacent concrete deterioration. Water leakage may be identified from the underside also by rust stains or leaching. Support ledges or beams should be reviewed for spalling, which may be due to corrosion of reinforcement, as discussed in Section 4.2.2.4, or may be due to frictional forces resulting from seasonal thermally-induced movements and lack of friction-reducing material at the interface between the support ledge and the supported slab. Spalling caused by this phenomenon may reoccur each winter. Again, spalled concrete that has not fallen should be removed. 4.2.2.7 Control Joints, Construction Joints Control joints are either those tooled into the uncured concrete during the construction process or those immediately sawcut into the hardened concrete to control normal shrinkage. The joint creates a plane of weakness which results in a crack under the joint. A sealant is then placed in the joint. Construction joints are the interface between two adjacent concrete pours during construction. Often they are sealed against leakage by a rubber water stop that spans the joint at about mid-height, or the top surface may be sawcut and sealed, as with a control joint. 4.2.2.8 Electrical Fixtures Electrical fixtures in slab soffits should be inspected for evidence of corrosion or water leakage. Water leakage from electrical fixtures may be symptomatic of problems with water penetration through structural elements, particularly in roofs of underground garages. Water in the electrical fixtures or conduits can cause shorting of electrical circuits. 4.2.2.9 Waterproofing and Traffic Toppings Traffic topping systems, whether elastomeric or cementitious, should be inspected for cracking, tearing, wear, debonding and spalling. Damage to the membrane under a slab traffic topping, or on the roof or wall of an underground garage, is not visible but may be indicated by leakage, staining or leaching on the surface of the concrete. 4.2.2.10 Exposed Reinforcing Steel

6

Whenever steel reinforcement is exposed, whether it is on a slab surface or soffit, a wall, a column, a ledge, or a beam, the possibility of a significant structural problem is indicated and the advice of a professional structural engineer should be sought. 4.2.2.11 Posttensioned Structures Once started, deterioration in post-tensioned structures can progress more rapidly than in cast-in-place reinforced concrete structures. Evidence of scaling, leaking, leaching, staining, spalling and cracking should be investigated immediately. Posttensioning tends to reduce the amount of cracking, therefore the presence of cracking in a post-tensioned structure may be more serious than in one of cast-in-place reinforced concrete. Rust stains on concrete surfaces at locations of anchors or stressing heads (such as slab ends) should be recorded. A professional structural engineer should be consulted to evaluate the significance of any signs of deterioration.

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4.2.2.12 Pretensioned Structures Problems in pre-tensioned structures tend to be associated more with joints and connections than with salt-accelerated slab corrosion. All joints should be inspected for signs of leakage and staining. Connections, particularly bearing areas, should be inspected for evidence of direct physical distress, including cracking and spalling of the adjacent concrete. 4.2.2.13 Steel Structures In addition to inspecting concrete elements for cracks, leakage, staining, leaching and spalling, checking for signs of distress in steel members must also be made. These investigations should probe for cracks, excessive deflection, distortion or buckling of steel members, or in portions of members such as beam flanges or webs, and any damage to corrosion protection, whether paint or galvanizing. Welded, bolted and riveted connections should similarly be inspected for signs of distress. Garage owners are encouraged to budget in advance for probable future repair expenditures. For instance, condominiums in Ontario are required by the Condominium Act to provide a "reserve fund" for major repair and replacement of common elements. Repairs to the parking structure are included in this category. Unfortunately, there have been many instances of major repairs being required in condominium garages for which adequate reserve funding was not available. This incident has resulted in special assessments to unit owners of several hundreds of dollars and, in some instances, several thousands of dollars. Whether a structure has already undergone a major restoration or not, a reserve fund should be established. Repairs need not always be carried out in one continuous contract. Repairs are often staged over a number of years for technical and/or financial reasons, but, whether done in one year or several, adequate reserve funding will soften the financial burden. This ongoing financial aspect of monitoring and maintenance must also be related to the economic considerations outlined in the Introduction of Chapter 3 (Repair Methods).

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4.3MONITORING PROCEDURES Monitoring must form an integral part of maintenance and repair programs to ensure public safety and maintain the structural integrity of a garage. The condition of the parking garage may be monitored by regularly scheduled walk-through surveys of the structure. A conscientious observer carrying out the survey should look for plugged floor drains; surface deterioration both on tops and undersides of floor and roof slabs; water leaks or stains through floors or walls; cracks in floors, beams, columns or walls; and rusting of exposed steel. Findings should be recorded where applicable on floor plans. Initially, a professional consultant may be engaged to conduct a condition survey. The frequency and extent of monitoring will depend on the condition of the garage, economic considerations and the capabilities of in-house staff. The frequencies recommended for these walk-through surveys should be considered minimum. 4.3.1 Drainage On a semi-monthly basis, all floor drains and any sump pumps should be checked to ensure that they are clear of debris and operating as intended. Any ponded water should be removed and its location noted on plan for possible remedial drain installation. 4.3.2 Floor Slabs 4.3.2.1 Unprotected Slabs On an annual basis (preferably in spring), check and record extent and location of surface cracking, concrete spalling, surface scaling, exposed reinforcing bars, leak or rust stains on the soffit, and of leakage itself. 4.3.2.2 Protected Suspended Slabs For slabs with membrane protection, an annual spring check of the driving surface should be carried out to record areas of wear, cracking, peeling or bulging of the membrane. For slabs with protective sealers, an annual check should be carried out to identify areas requiring resealing of cracks.

9

Undersides of beams and slabs should be surveyed to identify and record the extent and location of cracks, leaks or water staining, rust stains or exposed reinforcement. A significant increase in the extent of damage observed may indicate the need of a qualified professional consultant to conduct a more thorough investigation.

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4.3.3 Roof Slabs Undersides of beams and slabs should be surveyed to identify and record the extent and location of cracks, leaks or water staining, rust stains or exposed reinforcement. A significant increase in the extent of damage observed may indicate the need of a qualified professional consultant to conduct a more thorough investigation. 4.3.4 SlabsonGrade Annually check and record location of cracks, or of water seepage through cracks or joints at columns or walls and of water ponding. 4.3.5 Joints Expansion Joints should be checked annually (in spring) for damage or deterioration. For those joints filled with flexible material, the location and condition of the material should be recorded and, if leaking has occurred, repair or replacement should be planned in accordance with manufacturer's recommendations. Damage or deterioration of support ledges should also be noted. Control Joints should be checked annually (in spring) for damage, deterioration or leakage. The location and condition of the joint material should be recorded and any consequent repair or replacement should be made in accordance with manufacturer's recommendations. Construction Joints should be checked annually (in spring) to ensure that leakage does not occur. If water stains or leakage are observed, repairs should be made immediately. 4.3.6 Walls and Columns Walls and columns should be checked annually for cracks, leaks, water or rust staining, exposed reinforcing bars, delaminated concrete or vehicle damage. All defects are to be recorded on plans and, if a significant increase in the damage has occurred, a qualified professional consultant should be engaged.

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4.3.7 Electronic Monitoring New technology utilizing microprocessor-based monitoring devices are currently being developed and tested. Parking garage owners and operators should try to keep abreast of such developments.

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4.4 MAINTENANCE ROUTINES 4.4.1 Cleaning 4.4.1.1 Sweeping Sweeping of parking areas, by hand or mechanical sweepers, is necessary to remove loose dirt, debris and crystallized road salt during winter months. Accumulations of oil or grease should be removed by use of a non-corrosive degreaser. Regular sweeping helps to prevent clogging of floor drains and additional penetration of slabs by chlorides. Slabs should always be swept before wash-down. Care should be taken that the weight of mechanical sweepers does not exceed the structural capacity of the floor slab. 4.4.1.2 Washing Slabs may be washed down using a low-pressure hose to remove dust, dissolved and undissolved road salt. However, regular washing during winter months may contribute to chloride penetration by washing dissolved salt into cracks and unprotected surfaces. 4.4.1.3 Floor Drains Floor drains should be cleaned regularly, and especially after washing down floors. Drains should be inspected for signs of corrosion and mechanical damage, since concrete deterioration frequently occurs in the vicinity of drains. 4.4.1.4 Sumps and Sump Pumps Inspect sumps for accumulations of sand and debris and keep them clear. Check operating effectiveness of sump pump periodically. 4.4.2 Maintenance of Driving Surfaces Unprotected slabs (without sealers or membranes) should be checked twice yearly for signs of spalling or delamination. Temporary patching may be adopted to sustain use of driving surfaces, but permanent repairs should be implemented as soon as possible. Slabs protected by sealers should be maintained by

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periodic reapplication according to manufacturer's recommendations. Waterproofing membranes should be checked for deterioration and repairs made in accordance with manufacturer's specifications.

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4.4.3 Painting Painted surfaces (handrails, doors, windows and frames, pipes and other metal equipment) should be maintained in good condition to guard against corrosion of exposed surfaces. It is particularly important to paint exposed steel structural components (columns, girders, beams, bracing, etc.) of a parking structure. 4.4.4 Joints A visual check of all joints should be carried out on a regular basis. The need to remove and replace expansion joint material and control joint material periodically can usually be determined by observation of water leaks. 4.4.5 General Comments Regular maintenance duties should be utilized to complement the monitoring program by encouraging regular reporting from maintenance personnel after completing their daily tasks. All personnel should be trained to recognize signs of distress in every area of the parking garage. 4.4.6Schedules and Checklists For a maintenance program to be effective, routines should be scheduled to meet the specific requirements and needs of the parking area. General checklists, similar to that shown in the following "Planned Maintenance Schedule" (Table 4.1) are particularly helpful in establishing a systematic maintenance program. The "Parking Garage Maintenance Manual" prepared by the Parking Consultants Council of the National Parking Association (2000 K Street, N.W., Suite 350, Washington, D.C.20006) contains a detailed maintenance program and checklist, which should be consulted by owners and operators of parking garages. 4.5 ILLUSTRATIONS The photographs on pages 65 70 illustrate some consequences of poor maintenance in steelreinforced concrete garages.

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TABLE 4.1 PLANNED MAINTENANCE SCHEDULE +)))))))))))))))))))))0)))))))))))))))))))))))))))0))))))))))))))))))))))))), * ITEM * CHECK POINTS * REMEDIAL MEASURES * /)))))))))))))))))))))3)))))))))))))))))))))))))))3)))))))))))))))))))))))))1 * * * * * Carbon Monoxide * Check monitor to ensure * If inoperable, notify * * Monitor * power is on and that it * management. * * * is in working order. * * * * * * /)))))))))))))))))))))3)))))))))))))))))))))))))))3)))))))))))))))))))))))))1 * * * * * Ventilation Fans * Check fans to ascertain * If inoperable, notify * * * that they are in working * management. * * * order. * * * * * * /)))))))))))))))))))))3)))))))))))))))))))))))))))3)))))))))))))))))))))))))1 * * * * * Light Fixtures * Check fixtures to verify * Notify maintenance * * * that all lamps are * staff of location of * * * operating. Check for * any problems. * * * water leakage adjacent to * * * * or at light fixtures. * * * * * * /)))))))))))))))))))))3)))))))))))))))))))))))))))3)))))))))))))))))))))))))1 * * * * * Sweeping and * Check all areas for * Sweep, scrub and * * Cleaning * debris and accumulation * remove oil or grease. * * * of oil or grease on * * * * waterproofed slabs. * * * * * *

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/)))))))))))))))))))))3)))))))))))))))))))))))))))3)))))))))))))))))))))))))1 * * * * * Mechanical Cleaning * All parking areas, aisles * Machine sweep and * * * and ramps; dust, debris * machine scrub all * * * and salt from vehicles * surfaces regularly. * * * will accumulate on slabs * Frequency of sweeping * * * and ramps. * and scrubbing to be * * * * determined with regard * * * * to usage (i.e. rate of * * * * accumulation of dust, * * * * salt, sand and debris). * * * * * /)))))))))))))))))))))3)))))))))))))))))))))))))))3)))))))))))))))))))))))))1 * * * * * Water Ponding * Check and note areas * Squeegee water into * * * where water is ponding. * nearest drain. Advise * * * * management for possible * * * * future drain install- * * * * ation. * /)))))))))))))))))))))3)))))))))))))))))))))))))))3)))))))))))))))))))))))))1 * * * * * Drains and Sump Pump* Check drains to ensure * Notify maintenance * * * that they are clear of * staff to clean up * * * debris. Check sump to * drains. Notify main- * * * ensure that the pump is * tenance staff if pump * * * operating. * is not operating. * * * * * .)))))))))))))))))))))2)))))))))))))))))))))))))))2)))))))))))))))))))))))))-

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TABLE 4.1 (cont'd) PLANNED MAINTENANCE SCHEDULE +))))))))))))))))))))))0)))))))))))))))))))))))))))0)))))))))))))))))))))))), * ITEM * CHECK POINTS * REMEDIAL MEASURES * /))))))))))))))))))))))3)))))))))))))))))))))))))))3))))))))))))))))))))))))1 * * * * * Trench Drains * Check trench drains at * Clean out trench * * * entrances, etc. to * drains and flush with * * * ensure they are clean. * water as necessary. * * * * * /))))))))))))))))))))))3)))))))))))))))))))))))))))3))))))))))))))))))))))))1 * * * * * Unprotected * Check top surface for * All defects are to be * * Suspended Slabs and * cracks, wearing or scaling* recorded on drawings. * * Ramps * of concrete surface, ex- * If extensive, notify * * * posed reinforcement and * management for con- * * * damage to seals in cracks * sultant referral. * * * or expansion joints. * * * * Check bottom surface for * * * * cracks and leaks. * * * * * * /))))))))))))))))))))))3)))))))))))))))))))))))))))3))))))))))))))))))))))))1 * * * * * Waterproofed * Check wearing course for * All defects are to be * * Suspended Slabs and * wear, cracking, peeling * recorded on drawings. * * Ramps. * or bulging. Check expan- * If extensive, notify * * * sion joints for condition * management for con- * * * of joint sealer. Check * sultant referral. * * * underside for water leak- * * * * age, rust staining or * * * * exposed reinforcement. * * * * * * /))))))))))))))))))))))3)))))))))))))))))))))))))))3))))))))))))))))))))))))1 * * * * * Walls and Columns * Check walls for cracks, * All defects are to be * * * exposed reinforcement or * recorded on drawings. * * * water leakage. Check * If extensive, notify * * * columns for rust staining,* management for con- * * * scaling or exposed * sultant referral. * * * reinforcement. * * * * * * /))))))))))))))))))))))3)))))))))))))))))))))))))))3))))))))))))))))))))))))1 * * * * * Slabs and Ramps on * Check slabs for cracks at * Record location of * * Grade * columns and water seepage * cracks and water seep- * * * through cracks around * age. If extensive, * * * columns and at the * notify management for * * * junction between the slab * consultant referral. * * * and walls. * * * * * * /))))))))))))))))))))))3)))))))))))))))))))))))))))3))))))))))))))))))))))))1

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* * * * * Painting * Check painted guard rails,* Apply touch-up paint * * * hand rails and piping. * to exposed metal * * * Check painted traffic * objects. Notify man- * * * lines used for traffic * agement when peeling * * * control or parking. Check* of painted lines on * * * for rust spots on metal * floor slab occurs. * * * items. * * .))))))))))))))))))))))2)))))))))))))))))))))))))))2))))))))))))))))))))))))-

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FIGURE 4.1 Water leakage through crack in slab soffit.

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FIGURE 4.2 Evidence of water leakage through garage roof slab.

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FIGURE 4.3 Suspended slab with water leakage.

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FIGURE 4.4 Water pond formation at base of column.

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FIGURE 4.5 Spalled floor slab surface with exposed and corroded reinforcing steel.

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FIGURE 4.6 Spalling at base of column with exposed and corroded reinforcing steel. FIGURE 4.7 Spalled support ledge face at expansion joint with exposed reinforcing steel.

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FIGURE 4.8 Corroded and broken strands of posttensioning cable.

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APPENDIX 4A 1.Parking Garage Maintenance Manual, prepared by the Parking Consultants Council, National Parking Association. 2.Deterioration of Parking Structures: Extent, Causes and Repair Considerations (Sec. 5.0), prepared for CMHC. 3.Parking Structure Deterioration: A survey and analysis of its extent and influencing factors prepared for CMHC, Sec. 4.0. 4. CSA Standard S41387 Durable Parking Structures Appendix D.

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CHAPTER 5 ENFORCEMENT PROCEDURES

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5.0ENFORCEMENT PROCEDURES 5.1INTRODUCTION The Committee on the Deterioration and Repair of Parking Garages struck a Subcommittee to examine methods of enforcement, in the event that the Committee as a whole was to recommend the setting of minimum standards for structural safety in existing parking garages. Should the Committee recommend the setting of minimum structural safety requirements, the most appropriate method of enforcement of those standards would be dependent upon a number of factors: 1.Whether the minimum standard is to be mandatory or voluntary. 2.Whether it is to apply to all existing buildings (retrofit) or only to those undergoing material alteration or repair. 3.Whether it is to apply to all buildings in the province of a certain description. 4.Whether it is to apply only to structures which can be demonstrated to be structurally "unsafe". See Section 10 of the Ontario Building Code Act (BCA). 5.2 ISSUE The issue to be dealt with by the whole Committee is whether the problem is serious enough to require a provincial mandatory minimum standard or whether it is essentially a local problem to be dealt with as a property standards matter by the municipalities under their maintenance and occupancy standards by-laws. 5.3SUMMARY OF EXISTING REGULATORY FRAMEWORK The Sub-committee identified and examined some of the methods which are currently available to deal with building standards. 1.The Building Code (a regulation under the BCA) provides certain structural requirements for "storage garages". These requirements must be met when existing buildings are being altered, if the work is to be considered "material alteration or

2

repair". This means that voluntary construction which constitutes a material alteration or repair to existing buildings must comply with the Building Code. This Sub-committee cannot comment on the issue as to whether or not the current Building Code adequately addresses the structural issues being considered by the Committee as a whole.

3

2.Section 10 of the BCA allows orders to be made by an inspector where an existing building is structurally "unsafe". This section is rarely used at present and puts the onus on the building official to demonstrate that the structure is unsafe. At present, there are no criteria against which to measure the safety of this type of structure. 3.Maintenance and occupancy standards by-laws can be passed by municipalities pursuant to Section 31 of the Planning Act. However, the ability of municipalities to deal with certain matters is limited by the BCA and the Fire Marshal's Act, as there is no current provincial "Property Standards Act". Maintenance and occupancy standards bylaws vary from municipality to municipality in substance and in process; this was graphically presented in the report done by the Residential Improvement Division of CMHC dated September, 1986. It also was shown that such bylaws vary significantly right across Canada. 4.There is current legislation of various sorts dealing with "licensing or permits". This sort of legislation is directed to specific components of buildings, most notably the Elevating Devices Act, or, to specific types of occupancies, for example, the Nursing Homes Act and Arenas are dealt with under the Ministry of Labour. There is no provincial legislation at present which would require "retrofit" on a mandatory basis across the province to ensure structural safety. Retrofit for fire safety is being addressed under the Fire Marshal's Act by means of amendments to the Fire Code. 5.4 OPTIONS The options which the Sub-committee has considered are: 5.4.1Mandatory Retrofit Under the BCA Mandatory retrofit for structural safety, enforceable across the province, could be accomplished under the general structure of the present BCA. However, this would require new regulations to be filed under the BCA which would deal with structural safety in existing buildings. This option would also require some amendments to the BCA itself pursuant to the Regulations Authority section.

4

5.4.2Permits Relating to Structures Mandatory retrofit across the province could be enforced by separate legislation with a "permit" type provision similar to the Elevating Devices Act.

5

5.4.3Specific Standards Bylaws A specific standards by-law could be drafted which could be adopted optionally by municipalities and enforced through their own maintenance and occupancy standards by-laws. 5.5 DISCUSSION 1.If the Committee as a whole recommends a minimum standard which would be mandatory and provincial in nature, then the BCA, with appropriate amendments and with the addition in the regulations of a "code for existing buildings" becomes an attractive approach because: (a)The legislation is to a large extent in place. It provides for the delegation of authority, the identification of building officials the description of procedures, appeal structures, protection of building officials from civil liability, etc. In short, a good deal of the necessary machinery is already contained in the BCA. (b)The method chosen to enforce the mandatory province-wide standards should probably not be significantly different from current established practice. (c)The use of the BCA may help in avoiding proliferation of legislation which we believe should be one of the goals in the legislative process. (d)The use of a new or different method of enforcement for parking garages alone distorts the picture; there are other building safety issues which, in the near future, or indeed presently, must be addressed including such things as exterior cladding, balconies and other new problems with respect to parking structures and highrise developments which are today newly emerging as problems for tomorrow. We therefore must not lose sight of other structural safety and related problems which can be accommodated by amendments and further regulations under the BCA. (e)We believe great care must be taken in drafting any amendments to the BCA to ensure that the implication of the new standards are reasonably applied. 2.If the standard is to be mandatory and provincial in scope, another method of enforcement is by issuing permits for

6

structures: (a)This would require inspections at the instigation of the owner for periodic renewal of permits.

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(b)This approach clearly assigns the initial responsibility for identifying the problems to the owner, who must apply for the permit and have the application supported by the independent opinion of a qualified engineer. (c)This approach would require new legislation to deal with the same procedural issues that have already been addressed in the BCA (for example, delegation of authority to issue permits, appeals procedures, protection of inspectors, etc.). (d)The concept of permits casts a large net, which may not be justified. Permits would be required for specifically identifiable occupancies and would apply to all buildings that fell within that type of occupancy. The good and the bad must similarly obtain the periodic permit with the attendant engineering report to support the application. (e)Every owner within the specified type of occupancy would have to incur the expense of hiring a professional to "certify" that the garage should be permitted for a further period. (f)Should such permits apply only to parking structures, or to the whole building, bearing in mind that the parking structure, very often located below ground in a highrise structure, may have a significant impact on the remainder of the building itself. While elevating devices are licensed, for example, it may well be that the licensing of such a unique component of a building is more viable and susceptible to this form of treatment than is a parking structure. (g)This proposal places an onus on private engineers and architects to "certify" that the garage should be permitted to continue. This, we believe, presents an insurance coverage problem for the professional engineer or architect, depending on what such engineer or architect is being called upon to certify. It may well be that if the certificate is to require the engineer to opine that the structure meets the current minimum standards as set forth in the relevant legislation, the problem may not be as significant as it would be if the engineer or architect is being asked to certify that the structure is "safe". (h)It may be repugnant to force owners to hire third parties, such as engineers or architects, to determine compliance with the desired property standards. In other words, should the onus be left with the owner or is there an obligation on government

8

to enforce its standards by identifying problems through the provincial or municipal inspectors.

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3.If the minimum standard is not found to be something which should be mandatory across the province, the provincial government, or a standards committee might draw up a model structural safety minimum standard for parking garages which the municipalities would be able to adopt, at their option, as part of their maintenance and occupancy standards by-laws. (a)The jurisdiction of the municipalities to perform this function must be further considered, both from a legal and a practical standpoint. We have referred above to the comprehensive report prepared by CMHC dealing with a review of legislation across Canada in support of municipal maintenance and occupancy standards by-laws. This report highlights the great proliferation of municipal legislation dealing with this subject throughout Canada and cautions that, although there is no dearth of Ontario legislation, there are concerns about complexities, overlaps and possible conflicts among the various pieces of legislation directed to buildings in general. It is recognized in that report, and we agree, that the maintenance and occupancy by-laws of the various municipalities are still a necessary and effective tool, at least at present. The report also recognizes the absence of any overall provincial standard to enforce building standards. If one is looking for a provincial standard, a great deal can be learned from some of the very active municipalities within Ontario, particularly the City of Toronto and North York, on the matter of enforcement, but we do not feel that the search for an overall provincial standard should be abandoned in favour of leaving the matter solely within the jurisdiction of municipal by-laws under The Planning Act. (b)It seems that the key is a standardization of criteria across the province. The by-laws and standards set thereunder may vary from municipality to municipality, creating a significant problem for owners and developers to own and develop in various municipalities. (c)The enforcement of such diverse by-laws and standards is in itself diverse, which may cause confusion in the long run, but certainly within the province of Ontario, key examples can be found where the maintenance and occupancy standards have been applied with great advantage to the community and significant problems have been identified and remedied with a minimum of confrontation between the municipalities and owners. The City of North York has been particularly successful in this regard and their procedure is commended and recommended for further

10

consideration.

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5.6RECOMMENDATIONS 1.This Sub-committee views its mandate to consider enforcement as a province-wide goal in the context of province-wide standards. Based on our study performed in a short space of time, we recommend that two methods of enforcement be considered: (a)A scheme of mandatory retrofit under the BCA recognizing that amendments must be made to the BCA and further regulations filed under that Act. (b)Permits relating to structures. This would require, we believe, new legislation to authorize the issuing of permits relating to various types of structures, in which permits would have to be renewed on a periodic basis. 2.In the time available, this Subcommittee does not presume to reach a conclusion on either (a) or (b) above at this time, but we feel our function in this preliminary process is to identify the two possible approaches that are available. 3.Before a reasoned decision can be reached on (a) or (b) above, we strongly recommend that an impact study be performed, as it is recognized that the concept of issuing permits for structures is novel and the implications far-reaching. We therefore recommend that a steering committee be set up to monitor the impact on the various interests affected and that such a steering committee be composed of the following interest groups: (a) the insurance industry (b) engineers and architects (c) developers and contractors (d) owners groups (e) parking authorities (f) the real estate industry in general 4.Furthermore, we strongly recommend a detailed analysis from the other jurisdictions within Canada, and perhaps the United States, which are provincial or nonmunicipal in scope. This would be similar to the study done by CMHC as previously mentioned, which confined itself to municipal legislation.

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CHAPTER 6 DEVELOPMENT OF A COMMUNICATION STRATEGY

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6.0 DEVELOPMENT OF A COMMUNICATION STRATEGY 6.1 INTRODUCTION The technical content of the Advisory Document on the Deterioration, Repair and Maintenance of Parking Garages has been well prepared to provide stateoftheart information concerning: (a) types of parking structures (b) the nature of the corrosion process (c) factors affecting the rate of corrosion (d) techniques for the inspection of deterioration (e)recommended cost effective repair methods consistent with level of deterioration (f)recommended subsequent monitoring and maintenance procedures In addition, recommendations have been prepared for the enforcement of these procedures. The combination of these distinct, but interrelated phases of the requirements for safe and satisfactory performance of parking garages produces a document which is complete in itself, one which will do much to deal effectively with the problem. However, even the finest, most uptodate information is of little value unless it is widely disseminated and well understood by all those who are directly or indirectly affected by its ramifications. Therefore, it is vital that a carefully coordinated communication strategy be set in motion to ensure that this end is effectively achieved. The technical and enforcement aspects of the advisory document have been prepared largely by industry and legal representatives in coordination with the Ministry of Housing through Buildings Branch staff. It is essential that the cooperative communication of government and industry be maintained throughout the development and implementation of the communication strategy. 6.2 OBJECTIVE 6.2.1 Scope

2

The prime objective of the communication program is to reach and inform all those who are connected, either directly or indirectly, with the parking garage deterioration problem. Basically, the communication strategy must be devised to effectively educate the public at large. At the very least, it must indicate the severity of the issue and the importance of remedial measures to that sector of the public which is likely to be affected directly, either financially or through disruption of daily life. In this instance, the public is composed of a crosssection of society representing a wide variety of interests. That part of the public that has direct financial involvement can be classified broadly as follows:

3

(a) developers (b) building owners (c) shopping centre owners (d) parking garage operators (e) condominium owners Others that are not involved through ownership but who are likely to be brought into the problem through other direct or indirect means are as follows: (a) consulting engineers (b) building officials (c) material suppliers (d) contractors 6.2.3 Current Attitudes and Understanding At present, many responsible corporate owners have engaged consultants and contractors to carry out repairs on what obviously could be considered badly deteriorated parking structures. To a much more limited extent, certain condominium owner groups have, at their own instigation, decided to follow the same procedure. However, lack of knowledge or perhaps even an awareness of the problem is shared by a large proportion of the public and certainly by the vast majority of condominium owners. The latter group, condominium owners, represents a nontechnical faction, as distinct from all other sectors to be considered by the communication strategy. Many of these other groups may, in fact, be comprised of technically oriented staff, or may have technical personnel on staff, or at the very least, be within arm's reach of such expertise. However, condominium owners are not likely to be in this relatively favorable position. In addition to being nontechnical, this group is unlike the others in that its financial resources are much more restrictive since the burden of the cost of repairs falls on individual owners. The same may be said for investor groups formed by professionals who have purchased buildings for rental income and/or capital gains (i.e. MURBS). 6.2.4 Focus of Strategy From the foregoing, it can readily be seen that as categorized

4

by technical expertise and direct financial involvement, there really are three distinct groups within the audience. These are: (a) condominium owners and investors in MURBS (b) corporate and government owners (c) design and repair firms

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6.3 THE COMMUNICATION STRATEGY 6.3.1 Publications In Section 6.2 it was outlined that three different interest groups have to be addressed regarding the problem of deterioration and repair of parking garages. The first group, condominium owners and investors in MURBS, represents a largely nontechnical faction and for whom financial involvement is likely to be particulary onerous. It is vital, in dealing with this group, that a level of awareness be achieved through a means that would not cause undue panic either through concern of imminent structural collapse or of financially crippling repair costs. It is felt that this large group needs to be informed of the seriousness of parking garage deterioration in a direct but nontechnical way. This could be done by explaining the basis of the corrosion process, the need for proper repair and the serious ramifications of neglecting the problem, without creating undue alarm. 6.3.1.1 Illustrative Booklet To this end, the Communications SubCommittee recommends the production of a small booklet having a title that suggests "How to Care for Your Parking Garage". The booklet should be written in nontechnical language so as to be readily understood by the layman. To make it more readable, there should be a liberal use of simple illustrations. Information to be included would be: (a) the corrosion process (b) visible and hidden results of corrosion (c) repair options (d) range of repair costs (e) maintenance procedures (f) legal requirements (g) financial considerations Although it is suggested that this booklet be written in simple terms, it is important not to lose sight of the overall seriousness of the subject matter. For example, in addition to illustrative sketches to explain the numerous technicalities, it would be wise to include in the preface, a photograph of a collapsed portion of a parking garage. Such a pictorial demonstration of destroyed property, including automobiles,

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would indicate the serious potential result of neglected maintenance. In addition to discussing a range of costs associated with various repair methods and maintenance procedures, the booklet should provide advice on the settingup and managing of a reserve fund for condominium owners.

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This fund would obviate the impact of the heavy burden of repair costs which individual owners may not have considered in their personal financial programs. The preparation of this booklet calls for a special talent. It is the recommendation of the Communications Subcommittee that the Ministry of Housing engage the services of a suitably qualified consultant who would act in the capacity of technical writer and illustrator. The work would include careful paraphrasing of the reports from the technical subcommittees on investigation, repair, maintenance and enforcement. Close liaison with each of the five Subcommittees is essential in order to prepare a firstclass document. 6.3.1.2 Technical Report The above booklet is especially designed for condominium owners and would be equally satisfactory for any other nontechnical individual or group. However, as far as corporate or government owners, or design and repair firms are concerned, a more indepth technical publication is required. This publication would be a Technical Report containing the complete content of each of the technical reports from the Subcommittee on investigation, repair and maintenance. Once again, the services of a suitably qualified consultant are recommended to compile this information in a unified document. Each of the above reports has been prepared by a separate Subcommittee using its own unique style and format. Some overall editing will have to be carried out in order to achieve uniformity of format throughout the complete document. 6.3.2 Industry Involvement To finalize these two publications and to ensure their practicality, acceptability and usefulness, a request for review and comments should be made of the technical community. As soon as it can possibly be arranged, draft copies should be circulated to as wide a technical audience as possible. On the list for comments should be consulting engineers, repair contractors and material suppliers. The request should seek helpful comments to be returned by a reasonable date. 6.3.3 Public Involvement In line with the above procedure within industry, an opportunity

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for comments should be provided to the public at large. In this instance, rather than providing copies of documents to a defined, specific mailing list, widespread publicity of the opportunity for comments should be promoted through newspaper notices as well as television and radio announcements. Copies of documents would be sent to all those who respond to these announcements, again with a realistic time period for the return of comments.

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6.3.4 Publicity Once the comments are received and the two documents are in the final printing stages, an appropriate preplanned publicity campaign should be ready for implementation. The final form of this campaign depends on two things: whether or not a charge is to be imposed on one or both of the publications. The cost of preparing the documents will be considerable as it includes consultants' fees, paper, printing charges, handling comments and postal fees. Consequently, the Ministry of Housing may desire to recoup some of these costs by charging for the report and booklet. One has to realize that wide distribution of the information may be influenced by this charge. On the other hand, the enforcement provisions are likely to require individuals and corporations to comply with the procedures covered by either of the publications, so that purchase cannot effectively by avoided. At present, all technical requirements for buildings (Codes and Standards) carry a purchase price. Notification of the wide audience is the object of an effective publicity program. The communication strategy must identify all the various groups that fall within the technical or nontechnical fields relating to involvement in the investigation and repair of deteriorated parking garages. A comprehensive mailing list must be assembled from lists of MURBS investors, tax rolls, real estate lists, New Home Warranty Lists, the Canadian Institute of Public Real Estate Companies, the Multiple Dwelling Standards Association, the Urban Development Institute, the Building Owners' and Managers' Association, the Metro Toronto Apartment Builders' Association, the Housing and Urban Development Association, consulting engineers, contractors and suppliers. Announcements should be made in newspapers, on television and on radio concerning the booklet. Announcements should also be placed in trade journals relating to all aspects of the building industry concerning the technical report. Again, notification should be sent to the comprehensive mailing list discussed earlier in this section. Finally, a series of seminars, similar to those conducted by the Buildings Branch of the Ministry of Housing concerning changes in the Ontario Building Code, should be conducted in major centres throughout the province. This massive undertaking involves the development of a communication strategy, the preparation of a comprehensive mailing list, the canvassing of industry and the public, and the

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preparation of questionnaires for comments and the handling of replies. Clearly, this task is beyond the capabilities of a small Subcommittee composed of individuals who are able to contribute brief periods from their already busy schedules.

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It is the serious recommendation of the Communications Subcommittee to place this task in the hands of an experienced consultant. This must be a unique firm which has a satisfactory track record in organizing and implementing a successful communication strategy. We have had the opportunity of reviewing the work of one such firm Ashton & Associates Ltd. of Ottawa. The work in question was carried out for the Canada Mortgage and Housing Corporation. It involved the preparation of a communication strategy, the implementation of an industry solicited survey, the assessment of the responses to the survey and the reporting of observations and conclusions. The topic involved was a technical one which tested the ability of the firm to grasp the problem at hand and deal with it effectively. In checking the credentials of Ashton & Associates Ltd., it was learned that one of the senior partners has previously been involved in structural engineering projects. We would have no hesitation in recommending the services of this consulting firm.

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Buildings Branch 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 (416) 585-7385

April 21, 1988 Mr. John Bickley Chairman, CSA S413-87 Technical Committee TROW INC. 1595 Clark Boulevard Brampton, Ontario L6T 4V1 Dear Mr. Bickley: The Buildings Branch has completed its review of the comments expressed by the Advisory Committee members and other industry participants regarding CSA Standard S413-87 (Durable Parking Structures). The Buildings Branch staff has already acted upon the Committee's recommendations made at the meeting of January 28, 1988. With respect to the acceptance of CSA Standard S413-87, the majority of Committee members recommended its inclusion in the Ontario Building Code. The Buildings Branch accepted the Advisory Committee's recommendation. A new clause on parking structures referencing CSA Standard S413-87 is part of the new Code Amendment Package which will become effective starting May 20, 1988. The Committee also recommended that a Clause entitled "Alternative Design Solutions" be included in the Ontario Building Code in order to permit the use of other design methods capable of performing the same level of protection as stipulated in the Standard. The Ontario Building Code has already recognized this concern which Clause 4.1.1.4.(1)(b) in Part 4 of the OBC addresses. This clause states: /2

1

- 2 - "Buildings and their structural members shall be designed by one of the following methods, (a) standard design procedures and practices provided by this Part and

any standards and specifications referred to therein, except in cases of conflict the provisions of the building code shall govern; or

(b) one of the following three bases of design, (i) analysis based on generally established theory, (ii) evaluation of a given full scale structure or a prototype by a loading

test, (iii) studies of model analogues, provided the design is carried out by a person qualified in the specific method applied and provided the design ensures a level of safety and performance at least equivalent to that provided for or implicit in design carried out by the methods referred to in Clause (a)." As well, the Buildings Branch will publish an explanatory article on parking garage requirements in the Building Action Newsletter later this Spring. The Committee requested that all recommendations with respect to the text of CSA Standard S413-87 be forwarded to CSA for future revision. I have attached a list of categorized comments provided by Committee members and other industry participants regarding this Standard. Your expeditious attention to this matter would be most appreciated. Should you have any questions, please do not hesitate to contact me. Sincerely, Ali Arlani Technical Policy Advisor Encl. cc. Zain Shah

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Buildings Branch 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 (416) 585-7385

April 20, 1988 Mr. Alvin J. Houston Canadian Mortgage and Housing Corporation National Office Research Division Montreal Road Ottawa, Ontario K1A 0P7 Dear Mr. Houston: The Buildings Branch has completed its review of the comments expressed by the Advisory Committee members and other industry participants regarding CSA Standard S413-87 (Durable Parking Structures). The Buildings Branch staff has already acted upon the Committee's recommendations made at the meeting of January 28, 1988. With respect to the acceptance of CSA Standard S413-87, the majority of Committee members recommended its inclusion in the Ontario Building Code. (The voting pattern also indicated that there were two negative votes and one vote pending). The Buildings Branch accepted the Advisory Committee's recommendation. A new clause on parking structures referencing CSA Standard S413-87 is part of the new Code Amendment Package which will become effective starting May 20, 1988. The Committee also recommended that a Clause entitled "Alternative Design Solutions" be included in the Ontario Building Code in order to permit the use of other design methods capable of performing the same level of protection as stipulated in the Standard. The Ontario Building Code has already recognized this concern which Clause 4.1.1.4.(1)(b) in Part 4 of the OBC addresses. This clause states: /2

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- 2 - "Buildings and their structural members shall be designed by one of the following methods, (a) standard design procedures and practices provided by this Part and

any standards and specifications referred to therein, except in cases of conflict the provisions of the building code shall govern; or

(b) one of the following three bases of design, (i) analysis based on generally established theory, (ii) evaluation of a given full scale structure or a prototype by a loading

test, (iii) studies of model analogues, provided the design is carried out by a person qualified in the specific method applied and provided the design ensures a level of safety and performance at least equivalent to that provided for or implicit in design carried out by the methods referred to in Clause (a)." As well, the Buildings Branch will publish an explanatory article on parking garage requirements in the Building Action Newsletter later this Spring. The Committee requested that all recommendations with respect to the text of CSA Standard S413-87 be forwarded to CSA for future revision. A list of categorized comments provided by Committee Members and other industry participants has been forwarded to the Chairman of CSA Standard S413-87 Technical Committee. Attached for your information is a copy of the Advisory Committee's categorized comments as well as a copy of the March 1988 Building Action Newsletter. Should you have any questions, please do not hesitate to contact me. Sincerely, Ali Arlani Technical Policy Advisor Encl. cc. L. Lithgow

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Buildings Branch 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 (416) 585-7585 Date Address Dear The Buildings Branch has compiled the results from the Advisory Committee's meeting on January 28, 1988 regarding CSA Standard S413-87 (Durable Parking Structures). The Branch has also categorized the comments submitted by Committee members regarding this standard. With respect to the acceptance of CSA Standard S413-87, the majority of Committee members conditionally recommended its inclusion in the Ontario Building Code. The voting pattern also indicated that there were two negative votes and one vote pending. The Committee recommended that a Clause entitled "Alternative Design Solutions" be included in CSA Standard S413-87 in order to permit the use of other design methods capable of performing the same level of protection as stipulated in the Standard. This alternative is also part of Clause ( - ) in Part 4 of the Ontario Building Code. The Buildings Branch will address this issue in the Building Action Newsletter later this Spring. The Committee also requested that all recommendations with respect to the text of CSA Standard S413-87 be forwarded to CSA for future revision. /2

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- 2 - At the request of several Committee members following the meeting, the Buildings Branch has decided to provide the Advisory Committee with categorized comments regarding CSA Standard S413-87. A copy of these categorized comments will be submitted to the Canadian Standards Association. Sincerely Ali Arlani Technical Policy Advisor Encl.

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Buildings Branch 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 (416) 585-6651 File #: R 10-PG March 4, 1988 Mr. Allan Baxter General Manager Ready Mixed Concrete Association of Ontario 325 Eddystone Avenue Downsview, Ontario M3N 1H8 Dear Mr. Baxter: Thank you for your letter dated February 3, 1988 concerning CSA Standard S413-87, Parking Structures. The concerns raised by the Ready Mixed Concrete Association of Ontario were presented by Mr. Tibor Pal and discussed at the meeting held on January 28, 1988. The issues raised by your Association as well as those of the Committee Members were recorded and will be forwarded to the CSA Review Committee requesting prompt consideration. Should you have any further questions, please contact Mr. Ali Arlani of the Buildings Branch at 585-7385. Sincerely, D. Hodgson Executive Director ex. BAXTER.1 RDG

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Buildings Branch 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 (416) 585-6651 March 4, 1988 Mr. Robert Maling Ontario New Home Warranty Program 600 Eglinton Avenue East Toronto, Ontario M4P 1P3 Dear Mr. Maling: Thank you for your letter of February 2, 1988 stating your concerns regarding the inclusion of CSA Standard S413-87 in the Ontario Building Code. With respect to voting procedures, the protocol of the Advisory Committee was such that only Committee members were permitted to vote. However, the vote by Ontario New Home Warranty Program for the inclusion of CSA Standard S413-87 in the Ontario Building Code was considered a negative vote. The voting pattern showed that there were two negative votes and one pending vote. Regarding the concerns raised by Mr. Tibor Pal and the Ready Mixed Concrete Association, these were discussed both before and during the meeting. We would like to note that CSA Standards CAN 23.1 and CAN 23.3, which are currently under review, would include the same requirements for concrete quality as CSA Standard S413-87. As you are aware, CAN 23.1 and CAN 23.3 have been used extensively in the design of concrete structures (Part 4 of Ontario Building Code). With respect to the distribution of Committee members' letters, the issue was raised in the meeting and it was agreed that all letters should be distributed among Committee members; however, after the meeting several Committee members contacted the Branch to request that original letters not be distributed. Instead, a list of categorized comments on CSA Standard S413-87 will be distributed soon. The CSA Committee will be asked to address these and other concerns. /2

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- 2 - The recommendations that were approved by the Advisory Committee are: 1. CSA Standard S413-87 should be referenced in the Ontario Building Code. 2. In addition, a clause called Alternative Design Solutions should be included

to permit the use of other design methods capable of providing the same level of protection as CSA Standard S413-87.

3. All recommendations with respect to the text of the CSA Standard should

be forwarded to CSA for future revision. Unfortunately, when I talked to you on the telephone, I was not aware of the special procedure that had been put in place for this particular amendment. While the new parking garage standard is an important amendment, it has been included with a package of "housekeeping changes" which is due to be processed in the near future. We were able to accelerate the processing of the amendment in this way because we established the special Advisory Committee on the Deterioration, Repair and Maintenance of Parking Garages. We believe that the Advisory Committee was well qualified to provide a careful review of the issues involved in this matter and that this was the most expeditious and appropriate process to follow in this case. Thank you for drawing your concerns to my attention. Sincerely, David Hodgson Director

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CATEGORIZED RESPONSES TO CSA STANDARD S413-87 GENERAL COMMENTS 1. The CSA should put a Revision Committee together to undertake

revisions as technical information and guidelines are developed. 2. CSA Standard is good enough to be considered as state-of-the-art,

but not for a frozen standard. Certain important items have been omitted.

3. Some requirements of CSA Standard S413-87 deviate substantially

from the existing standard. There is concern that the industry may not be able to deliver or that the cost may be prohibitive.

4. Legal interpretation of some requirements may differ from that

intended in the Standard. 5. CSA Standard S413-87 should be adopted with amendments to be

made at a later date. 6. The Committee of CSA Standard S413-87 should promptly consider

modifications to clarify the following aspects:

-Field-related labour activities -Forming systems -Durability of thermoset and thermoplastic materials

7. Specific design requirements should have been described in the

Standard instead of cross-referencing other standards such as CAN3-A23.3.

8. The protection systems in the Standard are controversial. Some

acknowledgement of future development of other acceptable methods or materials for protection should be included.

9. Construction, inspection and maintenance requirements should be

made as a follow-up mandatory requirement. Some requirements are very vague and some specific adjustments have to be made to suit.

10. CSA Standard S413-87 limits the viable options to owners and

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designers.

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DESIGN 1. Table 1 on page 27 of CSA Standard S413-87 relates various Protection Systems to specific types of

concrete structures. Some of these recommendations require the combination of systems even though these combinations have no proven field experience whatsoever. Much is still not known about the actual performance of most of these systems.

2. Modifications to Table 1 (Minimum Protection Systems for Floors and Roofs). (a) For Structural System 1b (Heavy Use Areas): Membrane + all reinforcing bars on top as well as

bottom to be epoxy-coated.

(b) For Structural System 2, add the following note: Bonded tendons should be encouraged in parking structures.

(c) Epoxy-coated steel bars should be used in both light and heavy-use areas.

(d) Increase minimum actual cover to top steel to at least 40 mm (Clause 7.2.5).

3. A number of flaws exist in this Standard, including a number of contradictions.

-Table 1 requires all cast-in place concrete to be protected by a membrane, yet this requirement cannot be met in Clause 7.2.9 for concrete on steel deck systems where one side of the slab must be free to breathe.

-Section 4.1 states that all parking structures shall be provided with protection against corrosion and water leakage, yet the use of a sealer is permitted in Table 1 despite the fact that Appendix A confirms that sealers do not prevent water leakage.

4. Table 1 emphasizes preventing water leakage rather than preventing corrosion. 5. Cathodic Protection should be added to the OBC as an alternative and not a mandatory requirement. It

could be proposed in addition to the minimum protection system as per Table 1 for floors and roofs. 6. Cathodic Protection protects against corrosion and should be included in the list of minimum protection

systems (Table 1).

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7. There is disagreement with CSA's viewpoint that application of Cathodic Protection to new parking

structures is innovative and under development. Cathodic Protection references used in Appendix B are outdated (1984 or earlier).

8. There is a contradiction with respect to Clause 7.8.1. If Cathodic Protection is not recommended for

rebar, why does this clause indicate that heating elements in ramps should be corrosion resistant or cathodically protected.

9. The minimum protection systems in Table 1 are probably maximum cost protection systems. 10. Recommendations with respect to Cathodic Protection: (a) Upgrade concrete quality and cover. (b) Apply Cathodic Protection when and where a rebar potential survey indicates a need. (c) Treat cracks with elastomeric filler and covering material where and when they appear. (d) The weakness of the foregoing most cost-effective procedure is that it entails a continuing responsibility

of a property manager or owner, and may not get done in the long run. 11. Water and drain pipes should be mentioned specifically in Clause 7.7.1 together with electrical conduits

as potential sources of corrosion related problems. 12. Section 4.1 states that all parking structures shall be provided with protection against corrosion and water

leakage. The structural elements of parking structures include walls, slabs and columns, yet there are no requirements for leakage protection of garage walls. Experience has shown that leakage through these walls is quite frequent.

13. The recommendations in Appendix G should be mandatory as opposed to the requirement specified in

Clause 7.2.8. Considering the extent of delamination at the base of columns in garages, a 100 mm upturn of the membrane is inadequate.

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MATERIALS 1. CSA has no effective means to qualify products or systems for the following: 2. With respect to Clause 6.1.3 and CSA Standard CAN3-A23.1 regarding a concrete supplier's

responsibility for quality of concrete, it would be difficult to maintain the precise air void spacing in the design mix due to possible alterations to the concrete during placement and curing. Other concerns include the following:

(a) Responsibility: A supplier should only be responsible for concrete quality until the point of

delivery. (The concrete delivered will satisfy specifications and yield).

(b) Air Void Structure: The air void structure is difficult to maintain.

(c) ASTM Standards: With respect to ASTM Standards referenced in Section 6.1.10 of CSA

Standard S413-87, identical hardened concrete core samples may yield different air void ratios depending on the magnification used in linear traverse testing.

3. With respect to Clause 6.1.4, since there are indications that some superplasticizing admixtures may result

in excessive shrinking and cracking, a cautionary note should be included in the Standard for the designer to evaluate the effects of admixtures on the quality of concrete.

4. Sealers are effective in reducing the ingress of water and de-icing salts. Quality sealers with a proven

track record that are correctly applied to a well-prepared surface is a technically viable alternative and economical protection system, provided a reliable maintenance and monitoring program is subsequently implemented.

5. A major issue regarding the use of sealers is the cracking of concrete. Although sealers do not bridge

cracks, cracks can be repaired before the application of a sealer. 6. Cracks can be present at the time of applying a protective systems, or they can occur after the system is in

place. Some membranes that pass test standards are not capable of bridging gaps that occur in the concrete several years after construction.

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7. Despite the statement made in Clause 6.6.1, Clause 6.6.3 requires the use of aluminum for floor drains.

This is a poor choice of first preference, when Appendix G, Clause 6.6.3 acknowledges the existence of controversy on this point.

(a) There have been problems involving drains with steel bodies or aluminum gratings in garages. (b There is an extremely serious problem in parking structures caused by corroding aluminum conduits

embedded in the concrete slab. (c) The performance of epoxy-coated cast iron drains, catch basins, manholes, etc. has been

satisfactory. There is disagreement with Appendix G which states that cast iron has not performed well in parking structures. The present policy of The Parking Authority of Toronto is to permit only epoxy-coated cast iron floor drains in garage structures.

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DEFINITIONS 1. In the definition of "Durable", what is meant by "design life" and "significant deterioration"? 2. With respect to Membrane Requirements for Crack Bridging, who determines crack width? After what

period of time is crack width determined? INSPECTION AND TESTING 1. With respect to Appendix D, how can the air void structure of the placed concrete be checked? CONSTRUCTION 1. It is difficult and expensive (especially in winter) to wet-cure Portland Cement Concrete at a temperature

of 10oC for a minimum of 3 days. OPERATION AND MAINTENANCE 1. In Appendix B (Cathodic Protection), the operation and maintenance requirements under B5.1 and B5.2

are quite general and must be clarified. 2. When a sealer is used, cracks which develop in concrete are easier to monitor and repair. RESPONSIBILITIES 1. Although Appendix F is not a mandatory part of the Standard, it raises some very difficult legal questions

and legal responsibilities which should be the subject to further input by those immediately affected.

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COMMITTEE COMMENTS ON CSA STANDARD S413-87 C. Proctor * CSA should create a Revision/Standing Committee to undertake revisions.

* Ministry should ask CSA to review the Advisory Committee's recommendation and make changes where necessary.

B. Halsall * CSA Standard is good enough to be considered as state-of the-art but not as a frozen

Standard.

* There are important omissions in the Standard (unspecified). M. Rich * There is much professional disagreement with the various protection systems in the

Standard.

* The Standard recommends combination of systems that have no proven record.

* CSA has no effective means to qualify products or systems.

* Without specific performance standards which are the norm with most CSA standards, confusion and abuse will occur.

* If the CSA Standard is accepted, further research and field experience would be

impossible.

* More research is required to find effective means to protect concrete. Sufficient funding is required to thoroughly investigate this subject; such a project should be coordinated with similar projects.

P. Cody * CSA Standard may cause unnecessary confusion among professionals.

* Its incorporation into the OBC will eliminate other available and acceptable design options.

T. Pal * Some requirements of the CSA Standard deviate substantially from the existing Standard;

there is concern that the industry may not be able to deliver or the cost may be prohibitive.

* Legal interpretation of some requirements may defer from that intended in the

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Standard.

* He asks what is meant by "design life" and "significant deterioration"?

* Materials (6.1.3): CSA Standard CAN3-23.1 regarding a concrete supplier's responsibility for the air void spacing in the design mix which may be altered during placing and curing.

* Corrosion and Leakage Protection (4): Requirements for leakage protection of

garage walls is not covered in the Standard. Their experience with garages has been that leakage through walls is quite frequent.

* Membrane Requirements for Crack Bridging : Who determines crack width? Is the

critical crack width after the long-term shrinkage has occurred.

* Construction (10): It is difficult and expensive to wet-cure Portland Cement concrete at a temperature of 10 C for a minimum of three days.

* Inspection and Testing (Appendix D): How can the air void structure of the placed

concrete be checked? B. K. Nayyar * Generally has the same minimum design requirements as the CSA Standard, but with some

modifications to Table 1. - For structural system (1b) a membrane + all reinforcing bars on top as well

as bottom to be epoxy coated.

-For structural system (2) Note: bonded tendons should be encouraged in parking structures.

* Inspection and Testing per Appendix D should be included in the OBC.

* A system should be introduced so that a competent professional could review if

proper maintenance is maintained.

* Construction, inspection and maintenance requirements should be made as a follow-up mandatory requirement. Some requirements are very vague and some specific adjustments have to be made to suit.

* Cathodic protection should be added to the OBC as an alternative and not a

mandatory requirement. It could be proposed in addition to the minimum protection system as per Table 1 for floors and roofs.

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* In Appendix B (Cathodic Protection) the operation and maintenance requirements

under B5.1 and B5.2 are quite general and must be clarified. J. Bickley * CSA Standard should be adopted with amendments to be made at a later date.

J. Warren * Agrees entirely with the Standard. P. Jeffs * Supports the need and concept for a standard to cover the design and construction of

durable parking garages; however, the document should not be included in the OBC in its present form.

* The new Standard limits the viable options to owners and designers.

* Sealers are effective in reducing the ingress of water and de-icing salts.

* Quality sealers with a proven track record and that are correctly applied to a well-

prepared surface is a technically viable alternative and economical protection system, provided a reliable maintenance and monitoring program is subsequently implemented.

* A major issue about the use of sealer is the cracking of concrete. Although sealers

do not bridge cracks, cracks can be repaired before the application of a sealer.

* Cracks can be present at the time of applying a protective system, or they can occur after the system is in place. Some membranes (although they pass test standards) do not bridge cracks that occur in the concrete several years after construction.

* When a sealer is used, cracks are easier to monitor and repair.

L. Peterfy * Document is a good start towards preventing rapid deterioration of parking garages.

* (6.1.4) Since some superplasticizing admixtures may result in excessive shrinkage and cracking, a cautionary note should be included in the Standard for the designer to evaluate the effect of admixtures on the quality of concrete.

* (6.6) Despite the statement made in 6.6.1 and 6.6.3 which requires the use of

aluminum for floor drains, Appendix G 6.6.3 acknowledges the existence of controversy on this point.

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* Cast-iron drains, catch basins, manholes have performed satisfactorily; however, drains with steel bodies or aluminum gratings have had problems.

* The recommendations in Appendix G should be mandatory as opposed to the

requirement specified in 7.2.8. From the extent of delamination at the base of the columns in their garages, it is clear that a 100mm upturn of the membrane is insufficient.

* Water and drain pipes should be referred to in 7.7.1 together with electrical

conduits as potential sources of corrosion related problems; hence, their embeddment in concrete should be avoided.

A. Houston * Proposes the adoption of CSA Standard if the Committee who drafted the Standard is

prepared to promptly consider modifications to clarify the following aspects:

-field related labour activities - forming systems - durability of thermoset and thermoplastic materials M. Shirlaw * The Standard is deficient in certain aspects, but it represents a first step in establishing

requirements for new parking garages.

* The Standard should be adopted as soon as possible in order to get ahead of the garage deterioration problem.

E. Sanderson * The requirements of the Standard are clear and concise.

* Specific design requirements should have been described in the Standard instead of cross-referencing other standards (eg. Can A.23.3).

* The protection systems in the Standard is controversial. Some acknowledgement

of future development of other acceptable methods or materials for protection should be included.

T. Alexander * He believes that a number of flaws exist, including a number of contradictions.

* Eg: Table 1 requires all cast-in-place concrete to be protected by a membrane, yet this requirement cannot be met in Clause 7.2.9 for concrete on steel deck systems where one side of the slab must be free to breathe.

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* Eg: 4.1 states that all parking structures shall be provided with protection against

corrosion and water leakage, yet the use of a sealer is permitted in Table 1 (Minimum Protection Systems for Floors and Roofs) despite the fact that Appendix A confirms that sealers do not prevent water leakage.

Y. Uzumeri * The CSA Standard is not the ultimate, but it should be considered as an excellent first

issue. R. Loudon * Although not an expert in this field, he feels that the problem is chronic enough to warrant

a standard developed by capable and experienced people.

* Although Appendix F is not a mandatory part of the Standard, it raises some very difficult legal questions and legal responsibilities which should be subject to further input by those immediately affected.

J. Ryell * Recommends the use of epoxy-coated steel in both light and heavy-use areas.

* Increase minimum actual cover to top steel to at least 40mm (7.2.5).

* Do not allow the use of unbonded tendons in post-tensioned concrete elements (Section 8).

R. Querengesser * Feels that Cathodic Protection (CP) should be included in CSA Standard as a "Stand Alone

System". R.A. Gummov * Table 1 emphasizes preventing water leakage rather than preventing corrosion.

* Cathodic Protection protects against corrosion and should be included in the list of minimum protection systems.

* Does not agree with CSA's viewpoint that application of Cathodic Protection to

new parking structures is innovative and under development. Cathodic Protection references used in Appendix B are outdated (1984 or earlier).

* If CP is not recommended for rebar, why does it ask that heating elements in ramps

be corrosion resistant or cathodically protected (7.8).

* Feels that minimum protection systems in Table 1 are probably maximum cost

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protection systems. Recommendations - Upgrade concrete quality and cover.

- Apply CP when and where a rebar potential survey indicates a need.

- Treats cracks with elastomeric filler and covering material where and when they appear.

* The weakness of the foregoing most cost-effective procedure is that it entails a continuing responsibility of a property manager or owner, and may not get done in the long run.

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GENERAL COMMENTS 1. The definition of "Design Life" and "Significant Deterioration" to be clarified. 2. Membrane Requirements for Crack Bridging : Who determines crack width? Is the critical crack width

after the long-term shrinkage has occurred. 3. Although Appendix F is not a mandatory part of the Standard, it raises some very difficult legal questions

and legal responsibilities which should be subject to further input by those immediately affected.

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MATERIALS 1. CSA has no effective means to qualify products or systems. 2. Materials (6.1.3): CSA Standard CAN3-23.1 regarding a concrete supplier's responsibility for the air void

spacing in the design mix which may be altered during placing and curing. 3. Inspection and Testing (Appendix D): How can the air void structure of the placed concrete be checked? 4. (6.1.4) Since some superplasticizing admixtures may result in excessive shrinkage and cracking, a

cautionary note should be included in the Standard for the designer to evaluate the effect of admixtures on the quality of concrete.

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RECOMMENDATIONS 1. CSA should create a Revision/Standing Committee to review the Advisory Committee's recommendation

and make changes where necessary.

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DESIGN 1. Generally the same minimum requirements as the CSA Standard, but with some modifications to Table 1. - For structural system (1b) a membrane + all reinforcing bars on top as well as bottom to be epoxy

coated.

-For structural system (2) Note: bonded tendons should be encouraged in parking structures.

2. Cathodic protection should be added to the OBC as an alternative and not a mandatory requirement. It could be proposed in addition to the minimum protection system as per Table 1 for floors and roofs.

3. Water and drain pipes should be referred to in 7.7.1 together with electrical conduits as potential sources

of corrosion related problems; hence, their embeddment in concrete should be avoided. 4. Consider modifications to forming systems, as their design and use affect durability of the finished

structures. 5. The protection systems in the Standard is controversial. Some acknowledgement of future development

of other acceptable methods or materials for protection should be included. 6. There are a number of contradictions in the CSA Standard.

* Eg: Table 1 requires all cast-in-place concrete to be protected by a membrane, yet this requirement cannot be met in Clause 7.2.9 for concrete on steel deck systems where one side of the slab must be free to breathe.

* Eg: 4.1 states that all parking structures shall be provided with protection against corrosion and

water leakage, yet the use of a sealer is permitted in Table 1 (Minimum Protection Systems for Floors and Roofs) despite the fact that Appendix A confirms that sealers do not prevent water leakage.

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CONSTRUCTION 1. Construction (10): It is difficult and expensive to wet-cure Portland Cement concrete at a temperature of

10 C for a minimum of three days.

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OPERATION AND MAINTENANCE 1. In Appendix B (Cathodic Protection) the operation and maintenance requirements under B5.1 and B5.2

are quite general and must be clarified.

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Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. A.J. Houston Research Officer Canadian Mortgage and Housing Corporation National Office Research Division Montreal Road Ottawa, Ontario K1A 0P7 Dear Mr. Houston: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance as chairman in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

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Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. Tony Alexander Construction Control Ltd. Consulting Engineers 100 Spy Court Markham, Ontario L3R 5H6 Dear Mr. Alexander: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

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Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. G. Litvan National Research Council Building Materials Ottawa, Ontario K1A OR6 Dear Mr. Litvan: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

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Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. Jeoff Cook Proctor and Redfern Group Consulting Engineers, Architects and Planners 45 Green Belt Drive Don Mills, Ontario M3C 3K3 Dear Mr. Cook: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

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Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. John Ryell Trow Group 1595 Clark Blvd. Brampton, Ontario L6T 4V1 Dear Mr. Ryell: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

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Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. Glen Coley Corrosion Service Ltd. 369 Rimrock Road Downsview, Ontario M3J 3G2 Dear Mr. Coley: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

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Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. Don Clark Del Management Inc. 4800 Dufferin Street Downsview, Ontario M3H 5S9 Dear Mr. Clark: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

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Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. John Bickley Trow Group 1595 Clark Blvd. Brampton, Ontario L6T 4V1 Dear Mr. Bickley: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

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Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. D. Manning Ministry of Transportation and Communication Research and Development Branch 1201 Wilson Avenue Downsview, Ontario M3M 1J8 Dear Mr. Manning: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

9

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. H. Hakamaki Cluett Royl Restoration Ltd. 43 Cosentino Drive Scarborough, Ontario M1P 3A3 Dear Mr. Hakamaki: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

10

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. B. Halsall Halsall Robt and Associates 20 Holly Street Toronto, Ontario M4S 3B1 Dear Mr. Halsall: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

11

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. P. Jeffs FOSECO Canada Inc. 361 Speedvale Ave. West Guelph, Ontario N1H 1C7 Dear Mr. Jeffs: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

12

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. J. Warren Morrison Hershfield Ltd. 4 Lansing Square North York, Ontario M2J 1T1 Dear Mr. Warren: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

13

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. Ronald A. Daniel Executive Director CIPREC 123 Edward Street Suite 1210 Toronto, Ontario M5G 1E2 Dear Mr. Daniel: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

14

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. Tibor Pal Dowdell, Pal, Ellis and Assoc. Ltd. 3471 Kingston Road Scarborough, Ontario M1M 1R4 Dear Mr. Pal: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

15

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. R. Querengesser 20 Biaf Road Richmond Hill, Ontario L4C 8T1 Dear Mr. Querengesser: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

16

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. Michael Rich Lortex Associates Unit 62 1250 Mississauga Valley Blvd. Mississauga, Ontario L5A 3R6 Dear Mr. Rich: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

17

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. Bill Avard Pre-Con 35 Rutherford Road South Brampton, Ontario L6W 3J4 Dear Mr. Avard: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

18

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. B. Nayyar Ministry of Government Services 77 Wellesley Street West Ferguson Block, N.W. Rm. 1080 Toronto, Ontario M7S 1N6 Dear Mr. Nayyar: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

19

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. M. Shirlaw Construction Control Ltd. 100 Spy Court Markham, Ontario L3R 5H6 Dear Mr. Shirlaw: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

20

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. Cliff Proctor CMHC (Material Evaluation) National Office Montreal Road Ottawa, Ontario K1A 0P7 Dear Mr. Proctor: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

21

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. Yaman Uzumeri Building Commissioner, City of North York 5100 Yonge Street Willowdale, Ontario M2N 5V7 Dear Mr. Uzumeri: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

22

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. B. Loudon Housner, Henry, Loudon and Syron Suite 2000 145 King Street West Toronto, Ontario M5H 2B6 Dear Mr. Loudon: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

23

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. L. Peterfy The Parking Authority of Toronto 33 Queen Street East Toronto, Ontario M5C 1R5 Dear Mr. Peterfy: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

24

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. Larry Sie Morguard Investments Ltd. 505 Consumers Road Willowdale, Ontario M2J 4V8 Dear Mr. Sie: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

25

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. Ed Sanderson Ministry of Housing 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 Dear Mr. Sanderson: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

26

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. Fred Edgecombe The Society of the Plastics Industry of Canada 1262 Don Mills Road Don Mills, Ontario M3B 2W7 Dear Mr. Edgecombe: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

27

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mrs. Pavenah B. Cody Stanford Engineering Ltd. 800 Arrow Road Unit 8 Weston, Ontario M9M 2Z8 Dear Parvenah: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

28

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. Ed Sanderson Ministry of Housing 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 Dear Mr. Sanderson: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit

29

Attachment

30

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-6668 April 6, 1989 Mr. Robert Maling Ontario New Home Warranty Program 600 Eglinton Avenue East Toronto, Ontario M4P 1P3 Dear Mr. Maling: I am pleased to present you with the published copies of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Structures". Once again, I would like to thank you for your valuable assistance in producing the report. It is hoped that this report will achieve its intent. This report is being made available in French and English to the general public through the Ontario Government Bookstore. Sincerely, Ali G. Arlani Assistant Manager Code Development Unit Attachment

31

Buildings Branch 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 (416) 585-7385 April 20, 1988 Mr. J.M. Warren Vice President Morrison Hershfield Limited 4 Lansing Square North York, Ontario M2J 1T1 Dear Mr. Warren: I have received your letter dated April 5, 1988 regarding the March 1988 Building Action Newsletter article on Parking Garage Deterioration. The omission of your name along with the name of another member of the Advisory Committee was an editorial error on the part of the Branch staff. The Buildings Branch will clarify this issue in the next edition of the Newsletter. Please accept my sincere apologies regarding this matter. Sincerely, Ali Arlani Technical Policy Advisor

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ADVISORY COMMITTEE ON THE DETERIORATION, REPAIR AND MAINTENANCE OF EXISTING PARKING GARAGES 1:00 P.M. JANUARY 28, 1988 777 BAY STREET, TORONTO ROOM 10B AGENDA

1. Opening Remarks (Chairman) 2. Remarks by David Hodgson, Executive Director

Building Programs 3. Report on Comments Received (A. Arlani) 4. Committee Discussion/Recommendations 5. Closing Remarks (Chairman) 6. Adjournment

1

RECOMMENDATIONS 1. The CSA Standard should be referenced in the Ontario Building Code for Parking

Garage Design. 2. In addition, a clause called Alternative Design Solutions should be included to permit the

use of other design methods capable of performing the same level of protection as the CSA Standard.

3. All recommendations with respect to the text of the CSA Standard should be forwarded

to CSA for future revision.

2

Buildings Branch 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 (416) 585-7385 January 25, 1988 Dear Sir: This is to confirm that the next Advisory Committee meeting on Deterioration of Parking Garages will be held on Thursday January 28, 1988, at 1:00 p.m. in Boardroom 10B, 777 Bay Street (10th Floor). A luncheon will be provided between 12:00 to 1:00 p.m. in the same location. Sincerely, Ali Arlani Technical Policy Advisor

3

Buildings Branch 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 (416) 585-7385 File #: R 10-PG December 17, 1987 Dear Sir: Enclosed for your review, I am sending you a copy of the CSA Standard S413-87 on Parking Structures. In order to formulate the Advisory Committee's recommendations with respect to new construction, I would like you to review this standard and to submit your recommendations on the appropriateness of this standard for inclusion in the Ontario Building Code. For your reference, I am also enclosing a copy of the report by ACI Committee 362. Once all submissions are received, the information will be compiled and a series of recommendations will be developed. These recommendations will be presented to a full Committee meeting which will take place on January 28, 1988 (tentative date). Hence, I would appreciate if you could send me your comments by January 22, 1988 at the latest. The Advisory Document on "The Deterioration, Repair and Maintenance of Existing Parking Garages" is in its final editing stage and will be mailed to you as soon as it is completed. I would like to take this opportunity to express the Ministry's appreciation for your active participation in this Advisory Committee. If you have any further questions, please do not hesitate to contact me. Sincerely, Ali Arlani Technical Policy Advisor encl.

4

ex. PARK1 RDG

5

Building Programs 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 (416) 585-6651 March 28, 1988 MEMORANDUM TO: Gardner Church Deputy Minister FROM: Executive Director Building Programs RE: Deterioration of Concrete Parking Structures _________________________________________________________ The Canadian Institute of Public Real Estate Companies (CIPREC) in cooperation with the National Research Council of Canada (NRC) initiated a project to investigate the Deterioration of Concrete Parking Structures. The participants in this joint project are CIPREC, NRC, Canadian Mortgage and Housing Corporation, Public Works Canada and the Ministry of Housing. During the past year, they have monitored the performance of different design solutions in 37 parking garages and are planning for an additional 32 projects in 1988/89. Our financial contribution for this project last year was $20,000. The total cost of the project for 1988/89 is estimated to be $140,000. We have been requested to renew our financial contribution for an amount of $40,000. This amount is required as a startup fund for the purchase of necessary materials and equipment. Attached for your signature is a copy of the contract for this project. I concur D. Hodgson Gardner Church

6

Deputy Minister 7

FROM : Ali Arlani TO: D. Hodgson RE: Parking Structures: Additional Costs Associated with CSA Standard S413-87. ________________________________________________________________ The cost of building associated with CSA Standard S413-87 is considered relative to the cost of current professional practice. CSA Standard S413-87 specifies different requirements for different applications. It specifies that membranes be used for light-use areas, while heavy-use areas require the addition of epoxy-coated rebars (refer to Table 1 - Minimum Protection Systems for Floors and Roofs). It should be noted that while the new CSA Standard calls for membranes, this is already a common feature of current professional practice for new construction. Below is a list of premium costs associated with protection systems specified in CSA Standard S413-87. 1. Membranes: Additional cost of $2.50 to $3.00 per square foot. 2. Sealers: Sealers are less expensive than quality membranes. 3. Epoxy-Coated Rebars: Estimated additional cost of $1.00 to $2.00 per square foot. 4. Concrete: There is a minimal cost increase since the quality of concrete currently

being used in good design practice is similar to that specified in CSA Standard S413-87.

5. Cathodic Protection: Additional cost of approximately $3.60 per square foot.

Although Cathodic Protection can be used as a stand-alone protection system for parking structures, its use is limited to Ramp Heating in CSA Standard S413-87 (see Section 7.8).

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- 2 - 6. Concrete Curing: There are costs associated with construction processes in terms of

properly curing concrete. The specifications set out in CSA Standard S413-87 require wet curing for 3 days at 10 C in order to obtain a quality cured concrete which maintains the properties originally incorporated in the design mix. At present, we are not able to estimate the possible additional cost per square foot for these measures.

The total cost for protection of a particular parking garage will vary according to the combination of protective systems called for in Table 1. Repair Costs: It is estimated that the average repair cost of a light-use residential

building is $7.00 to $8.00 per square foot. Repairs can be expected 5 to 10 years after the initial construction of a traditionally built parking structure.

Enclosures ex. PARKGAR.CST

9

MEETING WITH SARAH JONES / MONDAY AUGUST 15, 1988 RE: TECHNICAL REPORT ON PARKING STRUCTURES 1. a) Front cover of technical report needs Ministry Logo

(communications to provide assistance). b) Avoid use of colour picture - very expensive and will not

reproduce well. 2. a) Send technical report to commercial printer. - reproduction quality is superior - typesetting is required for front cover - may take up to ten days 3. a) Freelance writer will be very expensive to write brochure. - Buildings Branch will have to finance it. - Consult with CCR for possible financial assistance. 4. Sarah Jones submitted three recommendations regarding promotion of

Technical Report.

1) Communications will assist in writing press release and sending to all industry and trade publications.

- Communications has a mailing list. - Mailing cost is the only expense involved.

2) Organize a series (6) of workshops or regional seminars (ie: Toronto, Ottawa, etc.).

-Have some members of the Advisory Committee attend. - Sarah Jones to help organize.

3) Publicize in Building Action Newsletter.

5. Sarah Jones recommends that 1000 copies be printed.

- 300 for responses from industry and trade publications. - 300 for responses from Building Action Newsletter. - 300 for Seminars. - 100 for general inquiries.

6. Sarah Jones to inform us about the cost of producing 1000 copies

from commercial printer. 7. Report must be released simultaneously in both French and

10

English versions. - Talk to Gladys regarding technical translation costs. - Find out about time involvement to translate document.

11

Buildings Branch 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 (416) 585-7385 February 23, 1988 Mr. Alvin J. Houston Canadian Mortgage and Housing Corporation National Office Research Division Montreal Road Ottawa, Ontario K1A 0P7 Dear Mr. Houston: I have enclosed a copy of the Overview Chapter of the Advisory Document on the Deterioration, Repair, and Maintenance of Parking Garages. Please note the absence of three references at the end of this chapter. I apologize for the delay in sending this document to you. Sincerely, Ali Arlani Technical Policy Advisor

12

Buildings Branch 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 (416) 585-6651 August 22, 1988 Mr. Canadian Mortgage and Housing Corporation National Office Research Division Montreal Road Ottawa, Ontario K1A 0P7 Dear Mr. : The Buildings Branch would like to extend its gratitude to CMHC for generously donating the diligent services of Mr. Alvin Houston who served as Chairman of the Advisory Committee on the Deterioration of Parking Garages. Much of the credit for the successful completion of this project is owed to Mr. Houston's diplomacy and skilled assistance. As a result of high demand by industry for the Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Garages, the Buildings Branch has decided to make this report public. The public document will consist of the three technical chapters of this report which include: the deterioration problem and inspection techniques; repair methods; and maintenance and monitoring procedures. With the successful completion of this technical study on parking structure, the Buildings Branch is looking forward to applying the methodology used in this report to the highrise building rehabilitation issue. Once again, the Buildings Branch is seeking the assistance of CMHC in undertaking this project. Sincerely, David Hodgson Director

13

ex. RDG

14

Buildings Branch 2nd Floor 777 Bay Street Toronto, Ontario M5G 2E5 (416) 585-7385 Oct. 20, 1988 Mr. A.J. Houston Research Officer Canadian Mortgage and Housing Corporation National Office Research Division Montreal Road Ottawa, Ontario K1A 0P7 Dear Mr. Houston: Thank you for sending me the Terms of Reference for the Cathodic Protection-related project. I have completed my review of the document and wish to offer the following comments. First of all, I would like to express our full support for CMHC's initiatives in dealing with problem of repair and restoration of deteriorated buildings. Your participation as Chairman of the Advisory Committee on Parking Garages and your involvement in the CIPREC project has been critical. I hope that the Corporation will continue to play a key role in future activities. With regard to this particular project, although I agree with the set objectives, I see some difficulty in achieving them. As you know, there is no industry consensus on the method of preparation, application, operation and structural suitability for Cathodic Protection (CP) applications. In my view, any manual or guideline that is developed by a single consultant, may not be acceptable to the entire industry. As well, CMHC's position on this matter might be controversial. I would suggest two alternative directions for this project: i) to pressure the CP industry to formulate a standard guideline and

until such guideline is developed, the application of the CP system in public housing projects be restricted and

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15

- 2 - ii) to proceed with the development of a manual or guideline through CSA,

Ontario Research Foundation or an organization of similar stature. I trust that you will find my comments useful. Truly, Ali G. Arlani Technical Policy Advisor

16

Buildings Branch 777 Bay Street

2nd Floor Toronto, Ontario M5G 2E5

(416) 585-7385

File #: R 10-PG April 19, 1988 Mr. A. Atrens Property Manager ANDREJIS MANAGEMENT INC. 4701 Steeles Avenue West Suite 203 Weston, Ontario M9L 1X2 Dear Mr. Atrens: Thank you for your interest regarding the deterioration of parking garages. As requested, I have enclosed a copy of the "Advisory Document on the Deterioration, Repair and Maintenance of Existing Parking Garages". This preliminary draft report was presented at technical seminars held in Montreal and Toronto. These seminars were conducted by the Nova Scotia Institute of Technology during the latter part of 1987. The final document is expected to be completed by the end of May 1988. Thank you once again for your interest in this project. Should you have any questions, please do not hesitate to contact me. Sincerely, Ali Arlani Technical Policy Advisor encl. ex. ATRENS.1 RDG

17

Buildings Branch 777 Bay Street

2nd Floor Toronto, Ontario M5G 2E5

(416) 585-7385

File #: R 10-PG September 7, 1988 Mr. David Bach Daybue Contracting Ltd. 130 LePage Court Unit 15 Downsview, Ontario M3J 3J1 Dear Mr. Bach: Enclosed for your perusal is a copy of the "Report of the Advisory Committee on the Deterioration, Repair and Maintenance of Parking Garages". Please note that this document is not an official Ministry publication. We ask that you treat this report in confidentiality. Should you have any questions, please do not hesitate to contact me. Sincerely, Ali Arlani Technical Policy Advisor encl. ex. BACH.1 RDG

18

Buildings Branch 777 Bay Street

2nd Floor Toronto, Ontario M5G 2E5

(416) 585-7385

March 14, 1988 Mr. Richard Booth Ontario Hydro 700 University Avenue H-13 Toronto, Ontario M5G 1X6 Dear Mr. Booth: Thank you for your interest regarding the deterioration of parking garages. As requested, I have enclosed a copy of the "Advisory Document on the Deterioration, Repair and Maintenance of Existing Parking Garages". Please note that this preliminary report is incomplete, with the absence of an overview and two final chapters. Thank you once again for your interest in this project. Should you have any questions, please do not hesitate to contact me. Sincerely, Ali Arlani Technical Policy Advisor

19

Buildings Branch 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 (416) 585-6651 File #: R 10-PG February 18, 1988 Ms. Patricia Brown The Valhalla Companies Ltd. 300 The East Mall Suite 101 Toronto, Ontario M9B 6B7 Dear Ms. Brown: Thank you for your letter of February 8 regarding the advisory committee document on deterioration of parking garages. The final report is in its final editing stages and will be published within the next few weeks. I will forward you a copy of the document when it becomes available. Thank you for your interest in this project. Should you have any further questions concerning the document, please contact Mr. Ali Arlani at 585-7385. Sincerely, David Hodgson Director ex. BROWN.1 RDG

20

Buildings Branch 777 Bay Street

2nd Floor Toronto, Ontario M5G 2E5

(416) 585-7385

April 20, 1988 Ms. Patricia Brown Executive Assistant The Valhalla Companies Limited 300 The East Mall, Suite 101 Toronto, Ontario M9B 6B7 Dear Ms. Brown, Thank you for your interest regarding the deterioration of parking garages. As requested, I have enclosed a copy of the "Advisory Document on the Deterioration, Repair and Maintenance of Existing Parking Garages". This preliminary draft report was presented at technical seminars held in Montreal and Toronto. These seminars were conducted by the Nova Scotia Institute of Technology during the latter part of 1987. The final document is expected to be completed by the end of May 1988. Thank you once again for your interest in this project. Should you have any questions, please do not hesitate to contact me. Sincerely, Ali Arlani Technical Policy Advisor encl.

21

Buildings Branch 777 Bay Street

2nd Floor Toronto, Ontario M5G 2E5

(416) 585-7385

April 21, 1988 Mr. Olindo Chiocca Stolp Homes 4950 Yonge Street Suite 1501 North York, Ontario M2N 6K1 Dear Mr. Chiocca: Thank you for your interest regarding the deterioration of parking garages. As requested, I have enclosed a copy of the "Advisory Document on the Deterioration, Repair and Maintenance of Existing Parking Garages". This preliminary draft report was presented at technical seminars held in Montreal and Toronto. These seminars were conducted by the Nova Scotia Institute of Technology during the latter part of 1987. The final document is expected to be completed by the end of May 1988. Thank you once again for your interest in this project. Should you have any questions, please do not hesitate to contact me. Sincerely, Ali Arlani Technical Policy Advisor encl.

22

Buildings Branch 777 Bay Street

2nd Floor Toronto, Ontario M5G 2E5

(416) 585-7385

April 20, 1988 Mr. L. Hadjuk Canadian Portland Cement Association 365 Bloor Street East Suite 1900 Toronto, Ontario M4W 2L4 Dear Mr. Hadjuk: Thank you for your interest regarding the deterioration of parking garages. As requested, I have enclosed a copy of the "Advisory Document on the Deterioration, Repair and Maintenance of Existing Parking Garages". This preliminary draft report was presented at technical seminars held in Montreal and Toronto. These seminars were conducted by the Nova Scotia Institute of Technology during the latter part of 1987. The final document is expected to be completed by the end of May 1988. Thank you once again for your interest in this project. Should you have any questions, please do not hesitate to contact me. Sincerely, Ali Arlani Technical Policy Advisor encl.

23

Buildings Branch 777 Bay Street

2nd Floor Toronto, Ontario M5G 2E5

(416) 585-7385

File #: R 10-PG April 19, 1988 Mr. Dave Hawkins Clerk's Department Scarborough Civic Centre 150 Burrough Drive Scarborough, Ontario M1P 4N7 Dear Mr. Hawkins: Thank you for your interest regarding the deterioration of parking garages. As requested, I have enclosed a copy of the "Advisory Document on the Deterioration, Repair and Maintenance of Existing Parking Garages". This preliminary draft report was presented at technical seminars held in Montreal and Toronto. These seminars were conducted by the Nova Scotia Institute of Technology during the latter part of 1987. The final document is expected to be completed by the end of May 1988. Thank you once again for your interest in this project. Should you have any questions, please do not hesitate to contact me. Sincerely, Ali Arlani Technical Policy Advisor encl. ex. HAWKINS.1 RDG

24

Buildings Branch 777 Bay Street

2nd Floor Toronto, Ontario M5G 2E5

(416) 585-7385

File #: R 10-PG April 19, 1988 Mr. R.J. Martin Loss Control Superintendent Zurich Insurance Company 188 University Avenue Toronto, Ontario M5H 3C3 Dear Mr. Martin: Thank you for your interest regarding the deterioration of parking garages. As requested, I have enclosed a copy of the "Advisory Document on the Deterioration, Repair and Maintenance of Existing Parking Garages". This preliminary draft report was presented at technical seminars held in Montreal and Toronto. These seminars were conducted by the Nova Scotia Institute of Technology during the latter part of 1987. The final document is expected to be completed by the end of May 1988. Thank you once again for your interest in this project. Should you have any questions, please do not hesitate to contact me. Sincerely, Ali Arlani Technical Policy Advisor encl. ex. MARTIN.1 RDG

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Buildings Branch 777 Bay Street

2nd Floor Toronto, Ontario M5G 2E5

(416) 585-7385

March 14, 1988 Mr. Peperkorn Human Resources Branch 400 University Avenue 2nd Floor Toronto, Ontario Dear Mr. Peperkorn: Thank you for your interest regarding the deterioration of parking garages. As requested, I have enclosed a copy of the "Advisory Document on the Deterioration, Repair and Maintenance of Existing Parking Garages". Please note that this preliminary report is incomplete, with the absence of an overview and two final chapters. Thank you once again for your interest in this project. Should you have any questions, please do not hesitate to contact me. Sincerely, Ali Arlani Technical Policy Advisor encl.

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Buildings Branch 777 Bay Street

2nd Floor Toronto, Ontario M5G 2E5

(416) 585-7385

File #: R 10-PG April 19, 1988 Mr. R.J. Scorgie BREIVIK SCORGIE WASYLKO ARCHITECTS INC. 370 Queens Avenue London, Ontario N6B 1X6 Dear Mr. Scorgie: Thank you for your interest regarding the deterioration of parking garages. As requested, I have enclosed a copy of the "Advisory Document on the Deterioration, Repair and Maintenance of Existing Parking Garages". This preliminary draft report was presented at technical seminars held in Montreal and Toronto. These seminars were conducted by the Nova Scotia Institute of Technology during the latter part of 1987. The final document is expected to be completed by the end of May 1988. Thank you once again for your interest in this project. Should you have any questions, please do not hesitate to contact me. Sincerely, Ali Arlani Technical Policy Advisor encl. ex. SCORGIE.1 RDG

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Buildings Branch 777 Bay Street

2nd Floor Toronto, Ontario M5G 2E5

(416) 585-7385

April 26, 1988 Mr. Wranghan SALT INSTITUTE 77 Metcalfe Street. Suite 306 Ottawa, Ontario K1P 5L6 Dear Mr. Wranghan: Thank you for your interest regarding the deterioration of parking garages. As requested, I have enclosed a copy of the "Advisory Document on the Deterioration, Repair and Maintenance of Existing Parking Garages". This preliminary draft report was presented at technical seminars held in Montreal and Toronto. These seminars were conducted by the Nova Scotia Institute of Technology during the latter part of 1987. The final document is expected to be completed by the end of May 1988. Thank you once again for your interest in this project. Should you have any questions, please do not hesitate to contact me. Sincerely, Ali Arlani Technical Policy Advisor Encl.

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Buildings Branch 777 Bay Street

2nd Floor Toronto, Ontario M5G 2E5

(416) 585-7385

File #: R 10-PG April 20, 1988 Mr. Declan Whelan Atkinson Engineering 786 King Street East Hamilton, Ontario L8M 1A6 Dear Mr. Whelan: Thank you for your interest regarding the deterioration of parking garages. As requested, I have enclosed a copy of the "Advisory Document on the Deterioration, Repair and Maintenance of Existing Parking Garages". This preliminary draft report was presented at technical seminars held in Montreal and Toronto. These seminars were conducted by the Nova Scotia Institute of Technology during the latter part of 1987. The final document is expected to be completed by the end of May 1988. Thank you once again for your interest in this project. Should you have any questions, please do not hesitate to contact me. Sincerely, Ali Arlani Technical Policy Advisor encl. ex. WHELAN.1 RDG

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30

31

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COMMITTEE MEMBERS ON PARKING GARAGES Mr. Alvin J. Houston Canadian Mortgage and Housing Corporation National Office Research Division Montreal Road Ottawa, Ontario K1A 0P7 Tel: (613) 748-2000 Mr. Tony Alexander Construction Control Ltd. Consulting Engineers 100 Spy Court Markham, Ontario L3R 5H6 Tel: 479-9770 Mr. G. Litvan National Research Council Building Materials Ottawa, Ontario K1A OR6 Tel: (613) 993-1596 Mr. Jeoff Cook Proctor and Redfern Group Consulting Engineers, Architects and Planners 45 Green Belt Drive Don Mills, Ontario M3C 3K3 Tel: 445-3600 Mr. John Ryell Trow Group 1595 Clark Blvd.

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Brampton, Ontario L6T 4V1 Tel: 793-9800

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Mr. Glen Coley Corrosion Service Ltd. 369 Rimrock Road Downsview, Ontario M3J 3G2 Tel: 630-2600 Mr. John Bickley Trow Group 1595 Clark Blvd. Brampton, Ontario L6T 4V1 Tel: 793-9800 Mr. D. Manning Ministry of Transportation and Communication Research and Development Branch 1201 Wilson Avenue Downsview, Ontario M3M 1J8 Tel: 235-4688 Mr. H. Hakamaki Cluett Royl Restoration Ltd. 43 Cosentino Drive Scarborough, Ontario M1P 3A3 Tel: 293-9432 Mr. B. Halsall Halsall Robt and Associates 20 Holly Street Toronto, Ontario M4S 3B1

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Tel: 487-5256 Mr. P. Jeffs FOSECO Canada Inc. 361 Speedvale Ave. West Guelph, Ontario N1H 1C7 Tel: (519) 822-6440 Mr. Fred Edgecombe The Society of the Plastics Industry of Canada 1262 Don Mills Road Don Mills, Ontario M3B 2W7 Tel: 449-3444 Mr. Don Clark Del Management Inc. 4800 Dufferin Street Downsview, Ontario M3H 5S9 Tel: 661-3640 Mr. Ed Sanderson Ministry of Housing 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 Tel: 585-6347 Mr. Larry Sie New Location: Mr. Larry Sie Morguard Investments Ltd. Morguard Investments Ltd. 6 Cresent Road 505 Consumers Road Toronto, Ontario Willowdale, Ontario

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M4W 2K9 M2J 4V8 Tel: 967-0880 Tel: 496-2098 Mr. L. Peterfy The Parking Authority of Toronto 33 Queen Street East Toronto, Ontario M5C 1R5 Tel: 393-7275 Mr. B. Loudon Housner, Henry, Loudon and Syron Suite 2000 145 King Street West Toronto, Ontario M5H 2B6 Tel: 362-3411 Mr. Yaman Uzumeri Building Commissioner, City of North York 5100 Yonge Street Willowdale, Ontario M2N 5V7 Tel: 224-6411 Mr. Cliff Proctor CMHC (Material Evaluation) National Office Montreal Road Ottawa, Ontario K1A 0P7 (613) 748-2000

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Mr. George Feher Ministry of Housing 777 Bay Street 2nd Floor Toronto, Ontario M5G 2E5 Tel: 585-6664 Mr. M. Shirlaw (New Address) Canadian Portland Cement Association Mr. M. Shirlaw 365 Bloor Street East Construction Control Ltd. Suite 1900 100 Spy Court Toronto, Ontario Markham, Ontario M9W 3L4 L3R 5H6 Tel: 920-4566 Tel: 479-9770 Mr. B. Nayyar Ministry of Government Services 77 Wellesley Street West Ferguson Block, N.W. Rm. 1080 Toronto, Ontario M7S 1N6 Tel: 965-6718

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Mr. Bill Avard Pre-Con 35 Rutherford Road South Brampton, Ontario L6W 3J4 Tel: 457-4140 Mr. Michael Rich Lortex Associates Unit 62 1250 Mississauga Valley Blvd. Mississauga, Ontario L5A 3R6 Tel: 276-0505 Mr. R. Querengesser 20 Biaf Road Richmond Hill, Ontario L4C 8T1 Tel: 884-6818 --------------------------------------------------------------------- NON-COMMITTEE MEMBERS ON PARKING GARAGES Mr. L. Alejski (Retired Jan. 8/88) (Home Address) Carruthers and Wallace Mr. L. Alejski 250 Merton Street 10 Bracondale Hill Road Toronto, Ontario Toronto, Ontario M4S 1B7 M6G 3P4 Tel: 489-0052 Tel: 656-6160 Mr. N. Spasevski (Left company 5 months ago) Construction Project Manager

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Cadillac-Fairview Corporation 5th Floor 20 Queen Street West Toronto, Ontario M5H 3R4 Tel: 598-8200

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Mr. S. Manglacasale Construction Manager (High-rise) Bramalea Limited 1867 Yonge Street Toronto, Ontario M4S 1Y5 Tel: 487-3861 Mr. Tibor Pal Dowdell, Pal, Ellis and Assoc. Ltd. 3471 Kingston Road Scarborough, Ontario M1M 1R4 Tel: 292-9988 Mr. Ronald A. Daniel Executive Director CIPREC 123 Edward Street Suite 1210 Toronto, Ontario M5G 1E2 Tel: 598-0694 Mr. J. Warren Morrison Hershfield Ltd. 4 Lansing Square North York, Ontario M2J 1T1 Tel: 499-3110

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DÉTÉRIORATION DES GARAGES

RAPPORT DU

COMITÉ CONSULTATIF

SUR LA DÉTÉRIORATION,

LA RÉPARATION ET LA MAINTENANCE

DES GARAGES

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Ministère du Logement Direction ontarienne du bâtiment

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RAPPORT DU

COMITÉ CONSULTATIF

SUR LA DÉTÉRIORATION,

LA RÉPARATION ET LA MAINTENANCE

DES GARAGES

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Ministère du Logement juillet 1988 Direction ontarienne du bâtiment

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SOMMAIRE En novembre 1986, le ministère du Logement a constitué un comité consultatif de spécialistes dans la province de l'Ontario pour s'occuper des questions relatives à la détérioration des structures des garages de la province, dont le nombre dépasse 3 000. Le Comité était chargé de préparer un rapport, accompagné de recommandations, visant le cas échéant à réduire le problème que causent les dommages - s'élevant à plus d'un milliard de dollars - provoqués par le chlorure dans les garages. Afin de garantir que les garages neufs ne subissent pas ces mêmes détériorations, le Comité a étudié la norme ACNOR S413-87 (Structures durables de stationnement) et recommandé son inclusion dans le Code du bâtiment de l'Ontario. Ce code exige que les nouvelles structures de garage soient conçues conformément à cette norme, en vigueur depuis le 20 mai 1988. La détérioration rapide et progressive des structures de garage provient essentiellement de la corrosion des éléments d'armature d'acier noyés dans le béton ou des tendons d'acier dans le béton postcontraint ou précontraint. Les structures d'acier ou composites d'acier peuvent également subir ces détériorations. Dans les structures en béton armé normal, la corrosion des éléments d'armature en acier se propage en exerçant des contraintes dans les parties voisines immédiates en béton qui finissent pas s'écailler et se fissurer. La corrosion est causée par les sels à base de chlorure répandus sur les routes en hiver et que les véhicules entraînent dans les garages. La combinaison du sel et de l'eau donne une solution saline qui s'infiltre dans les dalles de plancher en béton et amorce la corrosion des éléments d'armature d'acier non protégés, noyés dans le béton. Les inspections périodiques des structures des garages sont nécessaires pour s'assurer du maintien de la capacité de charge d'un étage de stationnement suspendu. Ces inspections servent aussi à s'informer sur l'état de la structure de façon à procéder aux travaux d'entretien et/ou de réparation en temps utile et dans des conditions rentables. Les méthodes d'inspection et les techniques de vérification en usage pour évaluer l'état des divers éléments d'un garage vont des techniques directes et simples qui n'exigent aucune compétence spéciale (rondes d'inspection) aux techniques évoluées qui font appel au service d'un ingénieur qualifié. Un début de détérioration exige des inspections régulières et des réparations périodiques, alors qu'une détérioration avancée oblige à adopter des mesures élaborées pour l'enrayer et réparer les dommages avant la défaillance de la structure. En dehors de l'exécution des réparations requises à ce point, on ne connaît pas de solution à longue échéance, pas plus que les frais qu'elle occasionne. De ce fait, il faut d'abord s'employer à mettre sur pied une liste de directives basées sur les connaissances courantes. Pour le moment, les réparations doivent se baser sur des inspections et des vérifications détaillées et régulières, sous la direction d'un ingénieur qualifié. Toute méthode raisonnablement efficace pour remédier au problème à l'avenir doit comprendre des évaluations des frais initiaux de réparations, des pertes causées par le manque à gagner pendant les réparations, des frais prévus pour l'inspection, l'entretien et les réparations futures.

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La surveillance doit faire partie intégrante des programmes efficaces de réparation et d'entretien pour garantir la sécurité du public et préserver l'intégrité structurale d'un garage. On doit assurer la surveillance, par des rondes régulières et fréquentes, pour noter la détérioration progressive des divers éléments de la structure. On peut ainsi établir un programme de maintenance fonctionnel et rentable fondé sur ces inspections. De plus, il faut établir un fond de réserve et un programme de travail organisé pour amortir correctement les répercussions financières de tout programme de maintenance. CONCLUSIONS GÉNÉRALES o Quelques structures de garage sont endommagées à un point tel qu'elles doivent faire immédiatement l'objet

de travaux de réparations importants, mais on peut considérer la détérioration, qui est irréversible dans la plupart des autres cas, comme un problème à long terme. D'ici 1992, on compte mettre sur pied un programme complet de réparation et de remise en état rentable, applicable et efficace.

o On doit mettre sur pied un plan de travail qui permette une étude technique pertinente (y compris les

conclusions de l'étude actuelle de L'Institut canadien des compagnies immobilières publiques) pour obtenir des renseignements supplémentaires sur l'existence et le rendement des matériaux, pour entreprendre des programmes appropriés de formation et mettre sur pied des formules des coûts d'exploitation et d'entretien pour les diverses techniques et structures en cause.

o Le temps nécessaire à la mise au point et à l'exécution d'un plan de travail provincial permettra aux

propriétaires d'évaluer en détail les répercussions économiques de ce problème sur les intéressés que sont les sociétés et les secteurs public et privé. Avec la mise en oeuvre de ce plan, les propriétaires seront en mesure de créer un cadre économique universel pour justifier et rendre abordables les frais inévitables d'une solution efficace.

o Voici quelques-uns des avantages pour l'avenir qui découlent de cette étude et de ses conséquences:

a) la recherche de mesures préventives efficaces pour éviter des problèmes similaires dans les futurs garages;

b) l'application de certaines des conclusions au problème de la remise en état des grands immeubles;

c) l'augmentation des revenus de l'industrie du bâtiment par l'exportation, fondée sur l'existence de besoins similaires de réparations à l'étranger.

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MEMBRES DU COMITÉ PRÉSIDENT M. Alvin J. Houston - Société canadienne d'hypothèques et de logement COORDINATEURS M. Ali Arlani - Ministère du Logement Mme. Parvaneh B. Cody - Stanford Engineering Ltd. 1) PROBLEME DE LA DÉTÉRIORATION ET TECHNIQUES D'INSPECTION *M. T. Alexander - Construction Control Ltd. M. G. Litvan - IRC/NRC M. J. Cook - Proctor Redfern Group M. J. Ryell - Trow Group M. G. Coley - Corrosion Service Ltd. 2) MÉTHODES DE RÉPARATION *M. J. Bickley - Trow/J.A. Bickley & Assoc. M. D. Manning - Min. des Transports et Communications M. H. Hakamaki - Cluett Royl Restoration Ltd. M. B. Halsall - Halsall Robt & Associates Ltd. M. P. Jeffs - Foseco Canada Inc. M. G. Coley - Corrosion Service Ltd. M. F. Edgecombe - The Soc. of the Plastics Industry 3) MÉTHODES DE MAINTENANCE ET DE SURVEILLANCE *M. D. Clark - Del Management Inc. M. E. Sanderson - OHC M. L. Sie - Morguard Investments Ltd. M. L. Peterfy - Toronto Parking Authority 4) MÉTHODES D'APPLICATION *M. B. Loudon, c.r. - Housner, Henry, Loudon and Syron M. Y. Uzumeri - Ville de North York M. C. Proctor - Société canadienne d'hypothèques et de logement M. G. Feher - Ministère du Logement 5) PROGRAMME DE COMMUNICATION *M. M. Shirlaw - Construction Control Ltd. M. B. Nayyar - Min. des Services gouvernementaux

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M. B. Avard - PreCon M. M. Rich - Lortex Associates M. R. Querengesser - Propriétaire AUTRES MEMBRES

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M. R. Daniel - CIPREC M. J. Warren - Morrison Hershfield Inc. * Président TABLE DES MATIERES PAGE SOMMAIRE ................................................................. i MEMBRES DU COMITÉ ........................................................ iii TABLE DES MATIERES ....................................................... iv LISTE DES TABLEAUX ....................................................... vi LISTE DES ILLUSTRATIONS .................................................. vii CHAPITRE 1.0 PROBLEME DE LA DÉTÉRIORATION ET

TECHNIQUES D'INSPECTION ......................................... 1

1.1 AVANT-PROPOS ............................................... 2

1.2 PORTÉE ..................................................... 2

1.3 NATURE DU PROCESSUS DE CORROSION ........................... 3

1.4 RÉPARATION DES GARAGES DÉTÉRIORÉS .......................... 6

1.5 INSPECTION ET VÉRIFICATION ................................. 7

1.6 RÉSUMÉ DES MÉTHODES COURANTES D'INSPECTION.................. 11

1.7 ILLUSTRATIONS .............................................. 12 2.0 MÉTHODES DE RÉPARATION .......................................... 26

2.1 AVANT-PROPOS ............................................... 27

2.2 SÉCURITÉ ................................................... 27

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2.3 CONSIDÉRATIONS ÉCONOMIQUES ................................. 28

2.4 RÉSUMÉ DES MÉTHODES DE RÉPARATION .......................... 29

2.5 CRITERES DE DÉCISION ....................................... 30

2.6 ÉVALUATION DES CONSEILS .................................... 30

2.7 SERVICES D'UN INGÉNIEUR-CONSEIL ............................ 31

2.8 ENTREPRENEURS EN RÉPARATIONS ............................... 31

2.9 FORMATION .................................................. 32

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CHAPITRE PAGE 3.0 MÉTHODES DE MAINTENANCE ET DE SURVEILLANCE ....................... 38

3.1 AVANT-PROPOS ................................................ 39

3.2 PORTÉE ...................................................... 39

3.3 MÉTHODES DE SURVEILLANCE .................................... 43

3.4 ENTRETIEN COURANT ........................................... 45

3.5 ILLUSTRATIONS ............................................... 47

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LISTE DES TABLEAUX TABLEAU PAGE 1.1 Méthodes simples d'inspection et de vérification ................... 13 2.1 Matrice de réparation des structures de garage ..................... 34 3.1 Programme de maintenance planifiée ................................. 48

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LISTE DES ILLUSTRATIONS ILLUSTRATION PAGE 1.1 Effondrement localisé d'une dalle de toit de garage ................ 17 1.2 Désagrégation de la surface d'une dalle de plancher ................ 17 1.3 Écaillement de la surface d'une dalle de plancher, occasionné par le gel et le dégel .................................. 18 1.4 Désagrégation de la surface d'une dalle de plancher, après enlèvement du béton effrité .................................. 19 1.5 Désagrégation d'une colonne ........................................ 20 1.6 Détérioration du mur extérieur d'un garage ......................... 21 1.7 Désagrégation d'une poutre ......................................... 21 1.8 Passage de la chaîne pour identifier les parties désagrégées de la surface supérieure d'une dalle de béton ..................................................... 22 1.9 Test de résistance à l'écrasement d'un échantillon de béton prélevé dans une dalle de plancher ........................ 22 1.10 Prélèvement d'un échantillon de béton d'une dalle de plancher à l'aide d'une sondeuse à carottes ..................... 23 1.11 Test d'une dalle de plancher réparée pour déterminer l'adhérence entre le béton de la dalle et le béton de réparation .............................. 24 2.1 Matrice de réparation des structures de garage ..................... 33 3.1 Suintement d'eau par une fissure dans le coté plafond de la dalle ................................................ 51 3.2 Suintement d'eau par la dalle de toit du garage .................... 52 3.3 Suintement d'eau par la dalle suspendue ............................ 53 3.4 Formation d'une flaque d'eau à la base d'une colonne ............... 54

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3.5 Effritement d'une dalle de plancher avec acier d'armature exposé et corrodé ....................................... 55 3.6 Effritement à la base d'une colonne avec acier d'armature exposé et corrodé ................................. 55 3.7 Effritement du bord d'appui au joint de dilatation avec acier d'armature exposé ............................ 56 3.8 Filins de câble de postcontrainte corrodés et brisés ............... 56

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CHAPITRE 1 PROBLEME DE LA DÉTÉRIORATION ET TECHNIQUES D'INSPECTION

56

1.0 PROBLEME DE LA DÉTÉRIORATION ET TECHNIQUES D'INSPECTION 1.1 AVANT-PROPOS Dans les garages, la corrosion des éléments de structure en acier est fréquente et essentiellement causée par le sel utilisé sur les routes en hiver. Il est maintenant évident que la détérioration des garages en béton provient de la corrosion (rouille) rapide de l'acier d'armature causée par l'infiltration progressive du sel dans le béton. On admet généralement que les normes et les méthodes utilisées jusqu'à présent dans la conception, la construction et la maintenance de ces ouvrages ne permettent pas d'en tirer un service et un rendement satisfaisants. Par conséquent, la plupart des structures de garages subissent une détérioration rapide et progressive qui, à moins d'être enrayée par des réparations, peut entraîner des défaillances de structure localisées et inattendues. Il faut s'inquiéter en particulier des dalles de plafond des garages souterrains, car elles sont souvent enterrées sous une chaussée ou des aménagements paysagers qui empêchent l'inspection courante du béton. Les dalles peuvent s'affaiblir par endroits à cause de la corrosion progressive de l'acier d'armature et de la désagrégation du béton qui en découle. 1.2 PORTÉE Le présent chapitre n'aborde que les questions se rapportant aux immeubles déjà construits. On doit consulter la norme ACNOR S413-87 (structures durables de stationnement) pour la conception des nouvelles structures de garages. 1.2.1 Types de garages Un garage peut se trouver au-dessus ou au-dessous du sol. On peut construire un garage à l'aide de différents types de structures. Le plus courant est le béton armé coulé en place. L'étage soutenu par des colonnes, des poutres et/ou des murs de différentes configurations constitue l'élément de structure de base. Les types les plus courants de systèmes de structures de garages sont: o Dalles plates en béton armé

Ce type de structure comprend des colonnes en béton armé soutenant des dalles plates, généralement dotées de panneaux surbaissés aux colonnes. On emploie souvent cette structure quand la hauteur et l'espace sont limités.

o Poutres et dalles en béton armé

On utilise couramment ce système lorsqu'on veut des travées plus longues entre les colonnes pour la construction des garages souterrains des immeubles et des structures indépendantes.

o Structures postcontraintes

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On utilise la postcontrainte partiellement ou totalement dans les structures pour réduire la profondeur de construction et la fissuration des éléments de structure.

o Structures en béton préfabriqué

On utilise des poutres en T ou des dalles standard pour construire les étages d'un garage. On peut soutenir ces éléments à l'aide de systèmes comme les colonnes et murs préfabriqués, les colonnes et murs en béton armé ou les ossatures en acier.

On emploie ce mode de construction quand on doit avoir des travées longues pour réduire le nombre de colonnes.

o Structures en acier

On utilise les ossatures en acier pour soutenir un ou plusieurs types de systèmes d'étages. Elles comprennent notamment le béton armé, les dalles ou poutres en T en béton préfabriqué ou le tablier métallique avec plancher mixte en béton.

1.2.2 Processus de détérioration Au-dessus et au-dessous du niveau du sol, le béton d'un garage peut être détérioré par des processus comme l'attaque par les sulfates, la réaction des agrégats alcalins ou le gel et le dégel. En général, les dommages de structure ne sont pas importants. La détérioration qui en découle n'est normalement ni rapide ni assez grave pour constituer un facteur notable de dégradation des garages. Cette détérioration du béton provient généralement de conditions spécifiques dans un lieu ou garage particulier; nous ne l'étudierons donc pas en détail. Nous avons déjà vu que la détérioration rapide et progressive de la structure d'un garage provient surtout de la corrosion de l'acier d'armature dans le béton ou des tendons d'acier dans le béton postcontraint ou précontraint. 1.3 NATURE DU PROCESSUS DE CORROSION 1.3.1 Corrosion de l'acier dans le béton L'acier se corrode normalement quand il est exposé à l'humidité et à l'oxygène de l'air. Dans la nature, le fer se présente sous la forme stable de la rouille (oxyde de fer), forme à laquelle il retourne si l'on ne prend pas de mesures de protection. Pour empêcher l'acier de se corroder, on peut le peindre ou l'enduire pour l'isoler de l'environnement. Cette mesure est efficace si l'on applique convenablement sur l'acier des enduits ayant de hautes propriétés diélectriques.

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On a utilisé avec succès l'acier d'armature sans protection spéciale quand le milieu alcalin créé par la haute teneur en chaux du béton forme une pellicule de protection continue sur la surface de l'acier et empêche la corrosion. Dans de telles conditions, l'acier se comporte plutôt comme un métal noble et inoxydable qui est devenu "passif". Cet état de passivité et de résistance à l'oxydation subsiste tant que l'on maintient un milieu très alcalin. Toutefois, si un agent "dépolarisant" neutralise la passivité ou empêche sa formation dans le béton, il élimine l'effet favorable de l'alcalinité et crée des conditions propices à la corrosion. L'ion chlorure est un dépolarisant courant et efficace. Les produits chimiques actuellement utilisés comme agents contre la formation du gel sur les routes sont malheureusement presque tous à base de chlorures; ils contiennent des chlorures de sodium et de calcium. La carbonatation de la chaux dans le béton conduit aussi à la corrosion de l'acier d'armature. Avec le gaz carbonique de l'air, l'alcalinité du milieu où se trouve l'acier diminue au point de détruire l'état passif du métal et de permettre la corrosion. La corrosion galvanique se produit en présence de deux ou plusieurs métaux dissemblables placés en contact électrique dans un milieu commun contenant humidité et/ou sel dissous. Dans ce genre de situation, un métal, qui fait fonction d'anode, se corrode partiellement ou totalement. Pour cette raison, il faut limiter au maximum l'emploi de métaux dissemblables. Dans les tabliers de garage, on ne doit noyer dans le béton que des métaux galvaniquement compatibles avec l'acier d'armature. L'acier galvanisé peut accélérer la corrosion de l'acier d'armature. Il peut aussi se former des cellules de corrosion entre des métaux semblables si les milieux où ils se trouvent sont différents, notamment quand les concentrations d'oxygène ou d'autres substances diffèrent. Quelle que soit la source de la corrosion, il en résulte une détérioration du béton armé du fait de la destruction du lien entre l'acier et le béton. De plus, l'accumulation de la rouille favorise le développement de contraintes et de fissures dans le béton. Sous sa forme la plus courante, cette détérioration entraîne la désagrégation de la surface de la dalle de béton. S'ils sont noyés dans du mortier, les tendons des structures en béton postcontraint ne représentent qu'une simple variation de l'acier d'armature. Si les tendons sont enduits de graisse ou gainés de plastique, la passivité ne se développe pas forcément. La protection provient alors de l'isolation de l'acier contre l'humidité, l'oxygène et les chlorures. La corrosion des tendons et de leurs ancrages a des conséquences très graves sur la capacité de charge et l'aptitude au service de la structure. En outre, la corrosion des tendons crée un danger sérieux pour les utilisateurs du garage, à cause du risque d'éjection d'un tendon endommagé hors de la dalle.

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1.3.2 Facteurs contribuant à la corrosion La corrosion de l'acier dans le béton se produit habituellement en présence de toutes les conditions d'environnement suivantes: o La concentration d'ions de chlorures solubles dépasse une certaine valeur de seuil. o La teneur en humidité du béton dépasse une certaine valeur de seuil. o L'oxygène est présent. o La température est favorable. Le régime de détérioration dépend de plusieurs facteurs. Les quantités d'humidité et d'oxygène doivent être suffisantes pour maintenir la réaction. La corrosion augmente généralement en fonction des quantités d'humidité, de sels et d'oxygène présentes dans le milieu. Dans la pratique, la mise en place d'une membrane imperméable ou l'application d'un scellant dans la surface de la dalle de béton est en principe favorable. Le drainage suffisant des planchers assuré par des surfaces inclinées et des drains convenablement situés réduit également la possibilité d'infiltration du sel et de l'eau dans le béton. Les facteurs régissant la désagrégation des dalles de planchers et de toits en béton après la construction sont: o Le type et la qualité de construction des dalles en ce qui concerne: - L'épaisseur de béton sur l'acier d'armature

-Le drainage

-La corrosité du béton o Les conditions du milieu où se trouve le béton armé (voir ci-dessus). Pendant les quelque premières années d'une structure de garage, il peut ne se produire aucune désagrégation, même si l'humidité et le sel s'accumulent dans le béton, au-dessus de l'acier d'armature. Jusqu'à ce point, la passivité de l'acier est préservée. La corrosion commence cependant dès que la passivité est détruite. Même si la corrosion se poursuit, la désagrégation ne se produit pas tant que l'agent corrosif, sur l'acier d'armature, ne crée pas de forces supérieures à la résistance à la traction du béton. Par suite, l'acier peut se corroder, sans aucun indice visible. Si l'on n'atténue pas la corrosion, la désagrégation se poursuit ensuite rapidement.

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La désagrégation du béton de la surface d'une dalle de plancher ou de toit d'un garage en béton armé normal se fait en trois phases: o pendant une période initiale de quelques années, il n'y a normalement aucune désagrégation; o pendant les quelques années suivantes, la désagrégation est rapide; o après la période de désagrégation rapide, celle-ci peut ralentir dans certaines conditions. La désagrégation de la face inférieure des dalles de béton se produit souvent, mais normalement beaucoup plus tard que celle de la face supérieure. Les chlorures et l'humidité s'infiltrent par le dessus de la dalle; de ce fait, la détérioration de la face supérieure se produit généralement en premier. La désagrégation de la face inférieure ne commence que si la teneur en chlorures autour de l'acier d'armature inférieur est assez élevée et si les conditions nécessaires du milieu sont présentes (la désagrégation ne commence qu'après la destruction de la passivité de l'acier inférieur). Il arrive fréquemment que la corrosion commence sur les fissures du béton par lesquelles le sel et l'humidité peuvent s'infiltrer facilement. 1.4 RÉPARATION DES GARAGES DÉTÉRIORÉS Les mesures favorables au ralentissement de la corrosion dans un garage sont limitées. Il n'est souvent ni pratique, ni économique, ni efficace d'appliquer ces mesures dans un garage ancien alors qu'elles donnent d'excellents résultats dans un garage neuf sans aucune contamination par le sel. Par exemple, il est rarement possible d'augmenter l'épaisseur de béton sur l'acier d'armature, d'enlever les canalisations noyées ou de remplacer la totalité du béton attaqué par les chlorures. La réparation des garages détériorés s'appuie sur des considérations techniques sérieuses. On ne doit la confier qu'à des consultants et des entrepreneurs expérimentés. La méthode la plus courante de réduction et de réparation des dommages (ci-après appelée réparation) consiste à ce point à réparer les parties détériorées de la dalle de plancher, puis à poser une membrane imperméable sur la face supérieure pour éviter toute autre infiltration d'eau et de sel dans et à travers la dalle. Cette méthode n'élimine pas forcément d'autres détériorations du béton, car les parties non réparées du béton, apparemment en bon état, peuvent être attaquées par le sel et sujettes à la détérioration. On a étudié intensivement les effets des réparations localisées sur la durabilité future des structures de garages. On suggère parfois que, malgré les limites de la réparation partielle avec pose d'une membrane imperméable, les réparations remettent non seulement les garages en état, mais la détérioration ultérieure ralentit dans la majorité des cas, s'il arrive qu'elle se produit de nouveau. Les réparations donnent de bien meilleurs résultats si on les entreprend aux premiers stades de la détérioration. D'autres rapports sur la réparation partielle (avec imperméabilisation) des dalles de plancher montrent que l'efficacité du système de remise en état varie énormément; dans certains cas, la détérioration se poursuit encore au fil des années. La remise en état des planchers de garage peut comprendre une ou plusieurs des options suivantes: application d'une protection cathodique pour neutraliser la corrosion de l'acier d'armature, pose d'une couche de béton supplémentaire sur la face supérieure des planchers et remplacement des ronds corrodés par des neufs ayant subi un traitement. Dans la planification des réparations, il faut se rendre compte que certaines mesures limitent les options pour les réparations futures. Par exemple, la protection cathodique exige la continuité électrique de l'acier d'armature. La

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résine époxy (matériau non conducteur), utilisée comme adhésif pour réparer ou enduire un ouvrage de béton neuf, peut réduire l'efficacité de la protection cathodique. D'autre part, si l'on n'isole pas le béton de réparation, exempt de chlorures, du béton et de l'acier d'armature déjà attaqués, au moyen d'un adhésif de résine époxy, on peut favoriser une forte corrosion localisée de l'acier immédiatement voisin de la section réparée. De même, l'application d'un scellant sur la surface de béton peut nuire à la bonne adhérence de la membrane imperméable sur la surface de béton, si l'on veut en poser une par la suite. Ces observations n'ont pas valeur de recommandation pour les réparations. Elles soulignent simplement ceci: 1. Quand la détérioration d'un garage a dépassé un certain stade, il faut prévoir des réparations périodiques. 2. La mise en oeuvre d'une méthode spécifique de réparation peut limiter les choix de réparations futures. La remise en état efficace d'un garage détérioré est complexe; elle fait appel à une expérience et à des connaissances approfondies de la part des intéressés. Le choix d'une méthode de remise en état qui utilise efficacement les ressources disponibles pour prolonger la durée de service d'une structure doit s'appuyer systématiquement sur l'étude des caractéristiques de chaque méthode offerte et de ses conséquences sur l'aptitude au service et la durabilité future de la structure. Avant de pouvoir mettre un programme de réparation en oeuvre, il faut procéder à l'inspection, à la vérification et à la collecte des données. 1.5 INSPECTION ET VÉRIFICATION 1.5.1 Avant-propos L'inspection périodique des structures de garages vise à déceler les faiblesses et la détérioration, du point de vue de la sécurité (capacité de charge des planchers suspendus) et du besoin de renseignements opportuns sur l'état des structures pour assurer entretien et réparation rapides et économiques. La présente section passe en revue les méthodes d'inspection et les techniques de vérification pour évaluer l'état des divers éléments d'un garage. On y trouve notamment des méthodes relativement simples n'exigeant aucune compétence particulière ou des techniques perfectionnées d'inspection et de vérification qui ne donnent normalement de résultats que si elles sont appliquées par le personnel qualifié d'un ingénieur ou d'un autre spécialiste. On n'aborde pas ici les inspections courantes faisant partie du travail normal d'entretien, comme la vérification du bon fonctionnement des systèmes de drainage, du chauffage des rampes d'accès ou du déblaiement de la neige. On ne parle pas non plus des dispositions de sécurité essentielles à la prévention des pannes de l'équipement ou de la détérioration prématurée des éléments de structure d'un garage. Les facteurs de l'environnement présents dans les garages ont des conséquences plus graves que dans la plupart des autres immeubles. En hiver, le sel, utilisé à profusion sur le réseau routier, pénètre le béton et y corrode l'acier d'armature. De plus, l'humidité et les températures extrêmes dans de nombreux garages ont tendance à favoriser une détérioration considérable. Pour ces raisons, on doit procéder à une maintenance et à une inspection des éléments des garages bien plus rigoureuses que pour les autres immeubles.

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1.5.2 Faiblesses des structures L'intégrité de structure est primordiale dans l'évaluation de la détérioration des garages. Si cette intégrité est affaiblie, il faut la rétablir et prendre des mesures pour maintenir la sécurité dans la structure. L'affaiblissement de structure peut s'interpréter comme un état dans lequel un ou plusieurs éléments d'un immeuble sont détériorés au point que la structure ne peut pas soutenir la charge prévue en toute sécurité. L'affaiblissement de structure peut se développer progressivement dans un garage sous l'effet de la corrosion de l'acier et de la désagrégation du béton qui en résulte. L'affaiblissement peut aussi provenir d'une ou de plusieurs des conditions suivantes: o Conception ou construction médiocre d'un élément de la structure conduisant à des défaillances comme:

-la fissuration des dalles de structure, en particulier près des appuis de colonnes;

-des fissures dans les éléments de soutien, en particulier des fissures de cisaillement dans les poutres et les tasseaux de soutien ou consoles;

-le fléchissement visible et anormal d'un élément de la structure.

La fissuration et le fléchissement peuvent indiquer des contraintes excessives, peut-être graves. o Mouvements thermiques

La plupart des garages subissent les effets de la dilatation et de la contraction causées par les variations de température. Ces effets, ajoutés au retrait et au fluage du béton, peuvent occasionner un affaiblissement considérable si l'on ne prend pas de mesures pour tenir compte des mouvements dus à ces facteurs.

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o Défaillances des appuis

Les appuis soutiennent les éléments de structure et permettent les mouvements thermiques.

La défaillance des appuis peut empêcher la structure de se comporter comme prévu; il peut en résulter un affaiblissement ou une défaillance de structure.

o Gel et dégel

Le gel et le dégel peuvent endommager le béton s'il n'est pas coulé avec des entrées d'air adéquates. o Surcharges

Des charges dépassant les limites prévues se produisent surtout aux étages supérieurs sans restriction de hauteur, dans les parties couvertes par des aménagements paysagers où la végétation peut considérablement augmenter les charges initialement prévues, aux charges d'impact dues aux dos d'âne anti-vitesse, etc.

o Défaillance des fondations

La défaillance des fondations peut occasionner des tassements différentiels dans la structure de soutien et se traduire par des tensions et des fissures anormales dans les éléments.

o Corrosion de l'acier d'armature

La corrosion de l'acier d'armature détruit le lien entre l'armature et le béton; il en résulte des fissures dans le béton et l'affaiblissement de l'intégrité de la structure.

o Corrosion des tendons postcontraints

La corrosion des tendons peut réduire la capacité de charge de la structure et finalement conduire à l'affaissement des éléments en cause. Elle peut aussi constituer un danger immédiat pour les usagers du garage, à cause de la possibilité d'un effondrement soudain.

o Défaillance des joints

Les joints permettent de tenir compte des mouvements thermiques; ils peuvent se détériorer s'ils ne sont pas bien conçus et installés. L'eau salée peut s'infiltrer dans le béton par un joint défectueux et causer la corrosion.

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1.5.3 Éléments de structure Quand on évalue les réparations nécessaires à une structure, les composants d'un garage que l'on inspecte et vérifie normalement sont: 1. Les fondations

Les fondations étant le plus souvent sous terre, on n'a normalement pas à s'en préoccuper. 2. Les colonnes

Ces éléments d'appui sont souvent exposés aux matières corrosives; il faut donc les protéger. 3. Les murs

Au-dessus et au-dessous du niveau du sol, les murs protègent des éléments extérieurs. Ils peuvent être exposés aux matières corrosives de l'intérieur et à l'infiltration de l'eau de l'extérieur.

4. Les poutres

Les poutres soutiennent horizontalement les dalles. 5. Les dalles

Les dalles soutiennent les charges des véhicules et des aménagements paysagers (cas des dalles de toit). 6. Les consoles et encorbellements

Ces éléments sont souvent joints aux colonnes et aux murs pour soutenir les poutres et les dalles. 1.5.4 Méthodes d'inspection et de vérification On peut diviser les méthodes d'inspection et de vérification en deux catégories: 1. Les méthodes simples font partie d'une ronde d'inspection, souvent à la charge du personnel d'entretien ou de

gérance dépendant du propriétaire, pour identifier et définir certains problèmes. L'examen visuel fait partie de cette ronde d'inspection.

2. Les méthodes plus élaborées sont du ressort d'un ingénieur compétent, généralement engagé par le propriétaire.

L'ingénieur prépare les recommandations de remise en état.

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1.6 RÉSUMÉ DES MÉTHODES COURANTES D'INSPECTION Le tableau 1.1 énumère les méthodes courantes d'inspection et de vérification qui servent à évaluer l'état des éléments d'un garage. Ces méthodes doivent toujours comprendre une inspection de la structure complète et la préparation de dossiers, avec photos et dessins, précisant l'aspect visuel de la structure au moment de l'inspection. 1.6.1 Autres considérations 1. En général, les autres éléments en béton armé d'un garage, comme les colonnes, murs, escaliers, puits

d'ascenseur et revêtements préfabriqués, sont moins touchés par les effets néfastes du sel et de l'eau que les dalles du plancher du garage. Il existe cependant des faiblesses analogues; on peut donc appliquer le plus souvent les méthodes de vérification mentionnées ci-dessus à tous les éléments en béton armé de la structure.

2. Dans certains garages où l'on utilise beaucoup d'éléments de structure en acier comme les poutres, colonnes et

systèmes de coffrage sous les dalles, les faiblesses les plus courantes sont:

-la corrosion aggravée par l'humidité et les chlorures;

-la fissuration de la structure causée par l'usure ou une construction médiocre;

-la déformation des éléments en acier causée par la surcharge ou les dommages dus aux chocs.

La corrosion par les piqûres peut réduire considérablement la capacité de charge des éléments en acier et provoquer la fissuration due aux tensions. La fissuration des éléments en acier peut avoir de graves répercussions sur l'aptitude au service de la structure, comme c'est aussi le cas des éléments pliés, tordus ou déformés.

3. Dans la plupart des cas de détérioration, de simples techniques d'inspection et de vérification ne suffisent pas

avec les éléments de structure dont les tendons d'acier postcontraints font partie de l'ouvrage en béton. Il est douteux qu'une ronde d'inspection révèle les défaillances du système postcontraint, car les tendons et les ancrages sont pour la plupart noyés dans le béton. Toute trace de corrosion, de fissuration ou de désagrégation aux ancrages ou d'apparition des tendons au-dessus ou au-dessous de la dalle indique que la capacité de charge et l'aptitude au service de la structure sont sérieusement compromises.

4. On peut détecter la désintégration du béton et le décollage des couches de membrane d'imperméabilisation en

frappant la surface et en notant les différences dans les bruits d'impact. Il est préférable de traîner une chaîne au sol sur les grandes surfaces. Pendant le déplacement d'un coté à l'autre de la chaîne, un bruit plus sourd indique normalement une désagrégation du béton ou un décollage de la membrane.

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1.6.2 Techniques élaborées et spécialisées d'inspection et de vérification L'examen détaillé de la structure d'un garage, au moyen de techniques spécialisées et de vérification, est essentiel pour déterminer l'étendue de la détérioration, son effet sur l'aptitude au service présente et future de la structure, la marche à suivre optimale d'entretien et de remise en état du garage et les diverses questions techniques et financières se rapportant à la remise en état. Un examen détaillé présente aussi une importance particulière dans les systèmes comme le béton postcontraint où l'inspection et la vérification simples ne permettent probablement pas d'identifier les défaillances. La constitution d'un dossier de données techniques, tirées de l'examen de l'état de la structure, est importante. Les dispositions de réparation sont ensuite basées sur ces données qui peuvent aussi servir à trancher les différends éventuels. On doit confier l'examen détaillé d'une structure à un personnel technique, le plus souvent des ingénieurs-conseils possédant l'expérience de ce travail. Il existe plusieurs directives (certaines préparées pour les ponts et chaussées) très utiles pour la planification et l'exécution de l'examen détaillé de l'état d'une structure. A cet effet, consulter l'annexe 1A. 1.7 ILLUSTRATIONS On trouvera des photos de défaillances typiques dans les structures en béton armé et de techniques d'inspection courantes aux pages 17 à 24.

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TABLEAU 1.1 MÉTHODES SIMPLES D'INSPECTION ET DE VÉRIFICATION Méthode de Conséquences probables Élément Défaillance vérification de la défaillance

1. Face supérieure de la dalle de toit soutenant des matériaux de remblayage (garage souterrain).

Dommages dus aux dos d'une anti-vitesse. Épaisseur excessive des matériaux de remblayage. Défaillance localisée de la membrane. Membrane décollée.

Acier mature corrodé et béton désagrégé.

Visuelle. Fosse d'inspection et consultation des plans. Fosse d'inspection et observation visuelle. Fosse d'inspection et observation visuelle. Enlèvement des matériaux de remblayage d'une petite partie de la dalle de toit.

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Tension de structure localisée dans la dalle de toit, occasionnée par les charges d'impact des roues des véhicules. Tension pouvant occasionner des fissures visibles sur la face inférieure de la dalle de toit. Tension des structures dans la dalle de toit. Tension pouvant se traduire par des fissures visibles sur la face inférieure de la dalle de toit. 1. Infiltration d'eau par

la dalle de toit. 2. Accumulation de sel

dans le béton, sous les parties pavées.

3. Corrosion de l'acier d'armature et désagrégation du béton.

Combinées avec la défaillance localisée de la membrane, ces conditions sont présentes avec:

1. l'infiltration de l'eau par la dalle de toit.

2. l'accumulation de sel dans le béton, sous la pa

rtie pavée.

Réduction locale de la capacité de charge de la dalle de toit.

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TABLEAU 1.1 (suite) MÉTHODES SIMPLES D'INSPECTION ET DE VÉRIFICATION Méthode de Conséquences probables Élément Défaillance vérification de la défaillance

Observations visuelles avec sondage (1) au marteau, à la barre d'acier ou avec chaîne.

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TABLEAU 1.1 (suite) MÉTHODES SIMPLES D'INSPECTION ET DE VÉRIFICATION Méthode de Conséquences probables Élément Défaillance vérification de la défaillance

2. Surface inférieure de la dalle de toit, d'étage de garage suspendu ou de rampes.

Parties humides ou mouillées. Fissures continues, relativement droites, étroites ou fines dans le béton (moins de 0,3 mm de large). Fissures moyennes ou larges, continues et relativement droites dans le béton (plus de 0,3 mm de large). Taches de rouille. Béton désagrégé (couche de béton tombée et exposant la face brisée du béton et de l'acier d'armature).

Visuelle. Visuelle, plus loupe et règle. Visuelle, plus loupe et règle. Visuelle. Visuelle avec sondage (1) au marteau ou à la barre d'acier.

Béton détérioré dans la dalle. Joints détériorés. Défaillance de la membrane imperméable. Défaillance du système de drainage. Infiltration de solutions d'eau salée. Corrosion de l'acier d'armature. Infiltration de solutions d'eau salée. Corrosion de l'acier d'armature. Si cette défaillance s'accompagne d'un fléchissement prononcé de la dalle de béton, la capacité de charge du plancher peut alors être très réduite. Corrosion de l'acier d'armature ou d'autres métaux noyés dans le béton. Corrosion de l'acier d'armature ou d'autres métaux noyés dans le béton. Surface importante de béton désagrégé pouvant réduire notablement la capacité de charge du plancher.

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TABLEAU 1.1 (suite) MÉTHODES SIMPLES D'INSPECTION ET DE VÉRIFICATION Méthode de Conséquences probables Élément Défaillance vérification de la défaillance

3. Face supérieure d'étages suspendus, de rampes, de planchers au niveau du sol. (Face exposée du béton).

Béton désagrégé (la couche de béton peut être enlevée, laissant apparaître la face fracturée du béton et de l'acier d'armature). Béton écaillé. Fissures étroites ou très minces, continues et relativement droites dans le béton (moins de 0,3 mm de large). Fissures moyennes ou larges, continues et relativement droites dans le béton (plus de 0,3 mm de large).

Visuelle avec sondage (1) au marteau, à la barre d'acier avec chaîne. Visuelle. Visuelle, plus loupe et règle. Visuelle, plus loupe et règle.

Corrosion de l'acier d'armature. Trous dans la surface du béton. Grandes surfaces de béton désagrégées pouvant réduire notablement la capacité de charge du plancher. Détérioration continue de la dalle de béton, de la face supérieure vers le bas. Infiltration de solutions d'eau salée. Corrosion de l'acier d'armature. Si cette défaillance s'accompagne d'un affaissement prononcé de la dalle de béton, la capacité de charge du plancher peut alors être très réduite. Infiltration de solutions d'eau salée. Corrosion de l'acier d'armature. Si cette défaillance s'accompagne d'un affaissement prononcé de la dalle de béton, la capacité de charge du plancher peut alors être très réduite.

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TABLEAU 1.1 (suite) MÉTHODES SIMPLES D'INSPECTION ET DE VÉRIFICATION Méthode de Conséquences probables Élément Défaillance vérification de la défaillance

4. Face supérieure d'étage suspendu ou de plancher au niveau du sol. (Surfaces de béton recouvertes d'une membrane imperméable et d'une couche d'usure).

Décollage de la membrane. Cloques et boursouflures de la membrane pouvant parfois s'accompagner d'une désagrégation évidente du béton. Fissures de la membrane. Déformation de la couche d'usure posée sur la membrane. Perte de la couche d'usure.

Visuelle avec sondage (1). Visuelle avec sondage (1). Visuelle avec sondage. Visuelle. Visuelle.

Infiltration d'eau et de sel dans le béton. Fissuration et désintégration de la membrane. Défaillance de la membrane. Corrosion de l'acier d'armature. Désagrégation du béton. Infiltration locale d'eau et de sel dans le béton. Si cette défaillance découle d'une fissuration dans la dalle de béton, il en résulte une infiltration d'eau salée. Désintégration de la couche d'usure et de la membrane. Désintégration de la membrane.

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ILLUSTRATION 1.1 Effondrement localisé d'une dalle de toit de garage.

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ILLUSTRATION 1.2 Désagrégation de la surface d'une dalle de plancher.

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ILLUSTRATION 1.3 Écaillement de la surface d'une dalle de plancher, occasionné par le gel et le dégel.

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ILLUSTRATION 1.4 Désagrégation de la surface d'une dalle de plancher,

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après enlèvement du béton effrité.

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ILLUSTRATION 1.5 Désagrégation d'une colonne.

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ILLUSTRATION 1.6 Détérioration du mur extérieur d'un garage.

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ILLUSTRATION 1.7 Détérioration d'une poutre. ILLUSTRATION 1.8 Passage de la chaîne pour identifier les parties désagrégées de la face supérieure d'une dalle de béton.

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ILLUSTRATION 1.9 Test de résistance à l'écrasement d'un échantillon de béton prélevé dans une dalle de plancher.

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ILLUSTRATION 1.10 Prélèvement d'un échantillon de béton d'une dalle de plancher à l'aide d'une sondeuse à carottes.

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ILLUSTRATION 1.11 Test d'une dalle de plancher réparée pour déterminer l'adhérence entre le béton de la dalle et le béton de réparation.

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ANNEXE 1A Bibliographie - Sources américaines 1. "Detecting Defects and Deterioration in Highway Structures". NCHRP Report #118, July 1985 Transportation Research Board National Research Council Washington, D.C. 2. "Guide for Making a Condition Survey of Concrete in Service". ACI Committee 201 Report 201, 1R-68 (Revised 1984) American Concrete Institute Detroit, Michigan 3. "State-of-the-Art Report on Parking Structures" ACI Committee Report ACI-326R-85 American Concrete Institute Detroit, Michigan Bibliographie - Sources canadiennes 4. "Bridge Deck Rehabilitation Manual, Part One: Condition Surveys", 1983 Ministère des Transports et Communications de l'Ontario Downsview (Ontario) 5. "Repair Techniques for Concrete Bridge Components", 1986 Roads and Transportation Association of Canada Ottawa (Ontario) 6. "Condition Survey", Total Building Performance Evaluation Travaux publics Canada, Architectural & Building Sciences octobre 1986.

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CHAPITRE 2 MÉTHODES DE RÉPARATION

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2.0 MÉTHODES DE RÉPARATION 2.1 AVANT-PROPOS D'après les mesures de l'étendue de la désagrégation et de la corrosion active, mesures parfois accompagnées de tests de charge, on peut estimer raisonnablement l'aptitude au service et la sécurité actuelle d'un garage. En se basant sur les renseignements obtenus dans le passé pour des structures semblables, on peut aussi évaluer le régime probable de détérioration. Il existe cependant d'importantes variations parmi les conditions existantes dans un garage que l'on ne peut ni expliquer, ni prévoir facilement. Les prévisions dépendent donc beaucoup de l'expérience et des qualifications de l'ingénieur chargé de l'examen. Avant de décider de la nécessité des réparations, ainsi que de leur type et de leur étendue, il faut d'abord considérer la sécurité et la rentabilité à longue échéance des méthodes à choisir. Les cas de défaillance de structure de garage sont heureusement très rares en Ontario. Les faces supérieures des dalles se détériorent souvent à un point tel que l'usage continu oblige à prendre des mesures correctives avant que la baisse de résistance devienne dangereuse. Propriétaires, municipalités et ingénieurs veillent généralement à faire des réparations avant l'affaiblissement critique de la structure. Il existe cependant très peu d'évaluations scientifiques de l'efficacité permanente des diverses méthodes de réparation adoptées. A mesure que l'on acquiert de l'expérience en la matière, les résultats s'avèrent de plus en plus inégaux; on est aussi moins certain de l'efficacité des méthodes de réparation soi-disant "de pointe". Il n'existe pas de solution facile à un problème donné. Chaque structure de garage présentant généralement plusieurs conditions différentes de détérioration, une méthode efficace et rentable exige l'étude des nombreuses considérations techniques et économiques qui s'imbriquent. 2.2 SÉCURITÉ La sécurité constitue le facteur essentiel des réparations. Un ingénieur expérimenté en béton armé peut analyser une structure de garage, évaluer judicieusement la résistance réduite de l'armature corrodée et conduire des tests de charge, conformément au code du bâtiment de l'Ontario, pour déterminer l'aptitude de la structure à supporter une charge prescrite. L'analyse dépend de l'estimation précise de la réduction de résistance de la structure. Un ingénieur averti penche du coté de la prudence. Les tests de charge ne peuvent donner que des résultats limités pour certaines parties, à certains moments. Les parties judicieusement choisies pour les tests de charge sont celles estimées très affaiblies, selon l'inspection visuelle ou d'autres tests. Avec une évaluation technique convenable, cette méthode est assez juste pour évaluer la sécurité des structures en béton armé normal. Elle peut être moins satisfaisante qu'une méthode d'évaluation de la sécurité de certaines structures précontraintes dans lesquelles la baisse de résistance peut être subite et dangereuse.

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Un test de charge n'indique pas la période pendant laquelle une structure reste suffisamment sûre, mais il peut servir à justifier l'utilisation continue d'un garage qui apparaît très affaibli, pendant la planification des réparations. Il peut aussi servir à vérifier l'efficacité d'une méthode de réparation dans la remise en état d'une structure. 2.3 CONSIDÉRATIONS ÉCONOMIQUES Dans la sélection d'un processus approprié de réparation, il faut analyser tous les facteurs avec soin, pour arriver à une solution équilibrée sur le plan des frais, de la compatibilité physique et de la durabilité ou de l'efficacité. Sur le plan économique, l'évaluation des travaux de réparation exige que l'on compare d'abord les différentes méthodes possibles avant d'engager des fonds. Une comparaison judicieuse des choix garantit que la méthode finalement choisie donnera les meilleurs résultats pour les fonds de réparation disponibles. Il serait peu profitable de procéder à la réparation totale de la structure, sans d'abord effectuer un traitement suffisant de la surface pour assurer la protection nécessaire pendant l'utilisation quotidienne normale du garage. Dans ces analyses, on applique les études des coûts d'exploitation et de maintien. En choisissant les méthodes de réparation, il faut veiller à ne pas se laisser exagérément influencer par les préférences personnelles. Il faut étudier tous les choix avec la même attention. Si l'on ne respecte pas cette recommandation, on se trouve dans une situation où les comparaisons ne sont pas basées sur des propositions équivalentes et les conclusions économiques peuvent être faussées. Il faut aussi examiner la fiscalité et ses répercussions pour le propriétaire du garage. Dans le cas des grandes sociétés immobilières, l'amortissement fiscal est permis pour compenser la dépréciation de la structure. En outre, les frais de réparation engagés pendant le cours normal de l'exploitation sont totalement déductibles du revenu. La législation actuelle n'encourage pas le promoteur à construire les parties à risque élevé d'une structure en appliquant des normes plus rigoureuses susceptibles de réduire le risque de détérioration. Les études des coûts d'exploitation et de maintien révèlent que, dans de nombreux cas, le promoteur se retrouve dans une meilleure position financière s'il construit le garage conformément au code établi et s'il accepte des réparations importantes cinq ans plus tard. Il peut déduire de son revenu les frais de réparation et recouvrer les autres pertes en augmentant les loyers. Il peut cependant être plus difficile de trouver des locataires pour un immeuble fréquemment en réparation. L'option fiscale n'est pas offerte aux propriétaires d'un immeuble en copropriété qui doivent donc envisager différemment les nombreuses options de réparation sur les plans de la technique et des frais.

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2.4 RÉSUMÉ DES MÉTHODES DE RÉPARATION Les méthodes de réparation utilisées comprennent: 1. L'enlèvement de la totalité du béton désagrégé, la réparation localisée et l'application d'une protection de

surface (ou protection cathodique). 2. L'enlèvement de la totalité du béton désagrégé ou de tout le béton dans les parties où les tests à l'électrode

donnent des lectures très négatives; le remplacement par du béton frais, suivi généralement de l'application d'une protection de surface.

3. L'enlèvement des parties désagrégées du béton détérioré et l'application d'une nouvelle couche de surface,

comme du béton armé de fibre de verre. 4. La réparation du béton détérioré, l'application d'une protection de surface pour réduire l'infiltration de

l'humidité et le suintement, et enfin la pose d'un système de protection cathodique sur la face inférieure ou supérieure de la dalle. Consulter le sommaire relatif à la protection cathodique dans l'annexe 2A.

5. L'élargissement des fissures à la fraise, suivi de leur scellement par la face supérieure ou de l'injection d'un

scellant par la face inférieure. 6. L'enlèvement total de la dalle ou de la couche supérieure de béton et son remplacement par du béton de

qualité contrôlée, des ronds enduits d'époxy et une protection de surface. Il existe de nombreuses variations aux quatre premières méthodes mentionnées. En général, on enlève complètement le béton désagrégé. On enduit fréquemment les ronds d'époxy. On utilise parfois un liant à l'époxy pour assurer l'adhérence de la partie remplacée et offrir une certaine isolation électrique. On ajoute parfois des additifs spéciaux au béton de réparation pour réduire la perméabilité et/ou la conductivité. Il existe de nombreux traitements de surface, comme les scellants et les membranes, qui ont tous des caractéristiques, des avantages et des inconvénients différents. On utilise divers traitements quand les ronds inférieurs des dalles et les ronds des colonnes se corrodent et provoquent la désagrégation. A la longue, les propriétaires, les consultants et les entrepreneurs acquièrent de l'expérience sur l'efficacité des nombreux traitements mentionnés et de leurs combinaisons. On doit chercher à profiter de cette expérience chaque fois que possible pour décider des méthodes de réparation d'un garage détérioré. Quand on a déterminé les méthodes semblant le mieux convenir aux besoins du propriétaire, il faut ensuite s'intéresser aux frais initiaux de réparation, aux frais causés par la perturbation de l'utilisation du garage pendant les travaux et aux frais concernant l'entretien et les réparations anticipés.

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Il faut également déterminer la période propice aux travaux, en évaluant les coûts et les avantages d'un délai par rapport au surcroît de détérioration se produisant pendant ce délai. Dans le choix de la meilleure méthode de réparation, il faut aussi tenir compte de la sécurité, de l'aptitude au service et des perturbations pendant les réparations, ainsi que des frais à court et à long terme. Un ingénieur-conseil expérimenté peut adresser des recommandations aux propriétaires, gérants d'immeubles, autorités municipales et autres, en vue de choisir le(s) traitement(s) convenant le mieux à chaque garage. 2.5 CRITERES DE DÉCISION Les facteurs de décision à envisager dans l'évaluation des différentes méthodes de réparation comprennent: 1. Considérations de sécurité publique 2. Prévision de la durée de service restante 3. Coûts d'exploitation et de maintien des différentes options 4. Liquidités de trésorerie 5. Tout changement proposé d'utilisation Une représentation graphique de la matrice de décision présentée aux propriétaires est jointe (Illustration 2.1 - Matrice de réparation des structures de garage). Le tableau 2.1 donne des extraits de cette illustration. Ce tableau ne donne pas les détails de construction requis pour la préparation des solutions de réparation d'un garage (joints, drainage, services, etc.) Les coûts initiaux et les frais d'entretien varient selon les solutions de réparation. Les solutions avec les coûts initiaux plus élevés peuvent être plus rentables à la longue (frais d'entretien plus bas), mais les liquidités de trésorerie peuvent les interdire. D'autre part, certaines solutions peuvent être très économiques, mais elles entraînent des frais d'entretien plus élevés. 2.6 ÉVALUATION DES CONSEILS Jusqu'à présent, on n'a pas encore publié de données revues par d'autres compétences concernant l'efficacité des matériaux et des systèmes de réparation, sur une grande échelle ou sur une longue période. Il n'existe pas de normes nationales qui traitent des problèmes de réparation des structures de garages. En attendant que l'on dispose de données plus fiables dans le temps, il est peu probable que de telles normes puissent être pratiquement définies. A l'heure actuelle, il faut s'appuyer sur l'expérience et le jugement d'un particulier ou d'un organisme spécialisé dans l'évaluation et la réparation des garages. 2.7 SERVICES D'UN INGÉNIEUR-CONSEIL L'analyse correcte des types et de l'étendue des détériorations est cruciale. Pour les méthodes à utiliser, consulter le

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document du sous-comité "Problème de la détérioration et techniques d'inspection". Il faut absolument appliquer des méthodes de réparation convenant au type de la structure en cause, au milieu auquel elle est soumise, à la durée utile et aux fonctions prévues par le propriétaire. Les services décrits dans les deux paragraphes précédents doivent être assurés par un ingénieur-conseil possédant la compétence et l'expérience nécessaires en structure et en réparation. On peut obtenir les noms d'entreprises fiables en s'adressant à: The Association of Professional Engineers of Ontario 1155, rue Yonge Bureau 101 Toronto (Ontario) M4T 2Y5 Téléphone: (416) 961-1100 The Consulting Engineers of Ontario 86, boul. Overlea Bureau 403 Toronto (Ontario) M4H 1C6 Téléphone: (416) 425-8027 On recommande au propriétaire de demander les renseignements suivants à l'ingénieur-conseil et de les étudier avant de retenir ses services: 1. Travaux semblables exécutés dans le passé. 2. Personnel, qualifications, expérience et effectif. 3. Références. 4. Participation du comité technique. 5. Connaissances en structures. 6. Articles publiés. 7. Liste des méthodes et des matériaux utilisés. 8. Ressources. 2.8 ENTREPRENEURS EN RÉPARATIONS Il existe une association ontarienne d'entrepreneurs en réparations dont l'adresse est la suivante: Concrete Restoration Association of Ontario 1, avenue Sparks Willowdale (Ontario) M2H 2W1 Téléphone: (416) 499-4000

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Cette association a une garantie standard qu'elle recommande et met à la disposition des propriétaires. Elle renseigne aussi sur les pratiques commerciales et les modalités équitables des contrats. On recommande à un propriétaire ou à ses ingénieurs-conseils de se procurer les renseignements suivants d'un entrepreneur en réparations et de les étudier avant de retenir ses services. 1. Travaux semblables exécutés dans le passé. 2. Personnel, qualifications, expérience et effectif. 3. Références. 4. Relations avec d'autres sociétés. 5. Participation du comité technique. 6. Liste des méthodes et des matériaux utilisés. 7. Ressources. 8. Cautionnement. 9. Proportions et types de travaux exécutés par l'entrepreneur. 10. Proportions et types de travaux exécutés par un sous-traitant. 2.9 FORMATION Plusieurs organismes organisent ou ont organisé des séminaires portant sur la remise en état des structures de garages. Ces séminaires intéressent les propriétaires, ingénieurs-conseils et entrepreneurs. L'association la plus importante est l'American Concrete Institute qui organise des séminaires très intéressants tous les ans. Pour plus de détails sur les séminaires de formation et la documentation, l'adresse de l'American Concrete Institute est la suivante: American Concrete Institute P.O. Box 19150 22400 West Seven Mile Road Detroit, Michigan USA 48219 Téléphone: (313) 532-2600

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FACTEURS DE DÉCISION

CONSIDÉRATIONS DE SÉCURITÉ PUBLIQUE

PRÉVISION DE LA DURÉE DE SERVICE RESTANTE

CO¼TS D'EXPLOITATION ET DE MAINTIEN DES OPTIONS

LIQUIDITÉS DE LA TRÉSORERIE

CHANGEMENTS PROPOSÉS D'UTILISATION OPTIONS REMPLACEMENT PAR PROTECTION PAR Coût Coût 1. Remplacement total élevé bas Béton perméable à basse teneur Vapeurs Système en chlorures de silice d'imperméabilisation Coût 2. Enlèvement de tout Latex initial le béton contaminé Béton modifié traditionnel Recouvrement 3. Enlèvement de tout le Iowa béton sous l'acier Scellant supérieur Polymère modifié 4. Réparations des parties Fibre Recouvrement désagrégées seulement modifiée de béton Coût de la maintenance 5. Réparations des Protection fissures seulement cathodique 6. Aucune réparation Surveillance de l'état de la structure

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Coût Coût bas élevé ILLUSTRATION 2.1 - MATRICE DE RÉPARATION DES STRUCTURES DE GARAGE (STRUCTURES EN BÉTON ARMÉ NORMAL)

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TABLEAU 2.1* MATRICE DE RÉPARATION DES STRUCTURES DE GARAGE - EXTRAITS DE L'ILLUSTRATION 2.1 +)))))))))))))))))))))))))0)))))))))0)))))))))))))))))))))))))0))))))))))))))))))))))), * Degré de détérioration/ * Solution* Matériaux de réparation * Méthode de réparation * * réparation * * * * /)))))))))))))))))))))))))3)))))))))3)))))))))))))))))))))))))3)))))))))))))))))))))))1 * * * * * * I. Remplacement total * 1 * Béton compatible + * Système d'imperméa- * * * * * * * enduits d'époxy * * * * * * * * * 2 * Béton compatible + * Scellant * * * * Nouveaux ronds * * * * * enduits d'époxy * * * * * * * * * 3 * Béton perméable à * Recouvrement de béton * * * * basse teneur en * - Vapeurs de silice * * * * chlorures + * - Latex modifié * * * * Nouveaux ronds * - Recouvrement Iowa * * * * enduits d'époxy * - Polymère modifié * * * * * - Fibre modifiée * * * * * * * * 4 * Béton compatible * Protection cathodique * * * * * + Scellant * * * * * * G4444444444444444444444444P444444444P4444444444444444444444444P44444444444444444444444I * * * * * * II. Enlèvement de tout * 1 * Béton compatible + * Système d'imperméa- * * le béton contaminé * * Nouveaux ronds * bilisation * * * * enduits d'époxy * * * * * * * * * 2 * Béton compatible + * Scellant * * * * Nouveaux ronds * * * * * enduits d'époxy * * * * * * * * * 3 * Béton perméable à * Recouvrement de béton * * * * basse teneur en * - Vapeurs de silice * * * * chlorures + * - Latex modifié * * * * Nouveaux ronds * - Recouvrement Iowa * * * * enduits d'époxy * - Polymère modifié * * * * * - Fibre modifiée * * * * * * * * 4 * Béton compatible * Protection cathodique * * * * * + Scellant * * * * * * .)))))))))))))))))))))))))2)))))))))2)))))))))))))))))))))))))2)))))))))))))))))))))))- * Ce tableau ne donne pas les détails de construction requis pour la préparation des solutions de réparation d'une structure de

garage (joints, drainages, services, etc.)

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TABLEAU 2.1* MATRICE DE RÉPARATION DES STRUCTURES DE GARAGE - EXTRAITS DE L'ILLUSTRATION 2.1 (suite) +)))))))))))))))))))))))))0)))))))))0)))))))))))))))))))))))))0))))))))))))))))))))))), * Degré de détérioration/ * Solution* Matériaux de réparation * Méthode de réparation * * réparation * * * * /)))))))))))))))))))))))))3)))))))))3)))))))))))))))))))))))))3)))))))))))))))))))))))1 * * * * * * III. Enlèvement de tout * 1 * Béton compatible + * Système d'imperméa- * * le béton sous * * Nouveaux ronds * bilisation * * l'armature * * enduits d'époxy * * * d'acier * * * * * supérieure * * * * * * 2 * Béton compatible + * Scellant * * * * Nouveaux ronds * * * * * enduits d'époxy * * * * * * * * * 3 * Béton perméable à * Recouvrement de béton * * * * basse teneur en * - Vapeurs de silice * * * * chlorures + * - Latex modifié * * * * Nouveaux ronds * - Recouvrement Iowa * * * * enduits d'époxy * - Polymère modifié * * * * * - Fibre modifiée * * * * * * * * 4 * Béton compatible * Protection cathodique * * * * * + Scellant * * * * * * G4444444444444444444444444P444444444P4444444444444444444444444P44444444444444444444444I * * * * * * IV. Réparations des * 1 * Béton compatible * Système d'imperméa- * * dégradations * * * bilisation * * seulement * * * * * * 2 * Béton compatible * Scellant * * * * * * * * 3 * Béton perméable à * Recouvrement de béton * * * * basse teneur en * - Vapeurs de silice * * * * chlorures * - Latex modifié * * * * * - Recouvrement Iowa * * * * * - Polymère modifié * * * * * - Fibre modifiée * * * * * * * * 4 * Béton compatible * Protection cathodique * * * * * + Scellant * * * * * * G4444444444444444444444444P444444444P4444444444444444444444444P44444444444444444444444I * * * * * * V. Réparations des * 1 * Néant * Système d'imperméa- * * fissures seulement * * * bilisation * * * 2 * Néant * Scellant * * * * * * * * 3 * Néant * Protection cathodique * * * * * *

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G4444444444444444444444444P444444444P4444444444444444444444444P44444444444444444444444I * * * * * * VI. Aucune réparation - * 1 * Néant * Néant * * Surveillance de * * * * * l'état de la * * * * * structure * * * * .)))))))))))))))))))))))))2)))))))))2)))))))))))))))))))))))))2)))))))))))))))))))))))- * Ce tableau ne donne pas les détails de construction requis pour la préparation des solutions de réparation d'une structure de

garage (joints, drainages, services, etc.)

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ANNEXE 2A Résumé de la fonction de la protection cathodique de l'acier d'armature dans les garages La protection cathodique est une technique électrochimique bien au point et largement utilisée pour combattre la corrosion des structures d'acier dans de nombreux milieux aqueux. Au cours des dix dernières années, plusieurs groupes de recherche du secteur public ont prouvé son efficacité pour protéger l'acier d'armature. La mise au point spécifique de systèmes de protection cathodique pour les structures en béton armé s'est faite rapidement depuis les essais initiaux au début des années 1970. Le système de protection cathodique le plus couramment utilisé dans les garages se compose d'anodes primaires en fil noyées dans une couche conductrice appliquée, après préparation adéquate, sur la face inférieure de la dalle en béton armé. La durée de ce système est directement proportionnelle à l'épaisseur de la couche qui est habituellement de 16/1000 de pouce. L'avantage principal de la protection cathodique par rapport aux méthodes de remise en état plus courantes réside dans la prévention de la corrosion qui réduit le besoin de travaux de réparation tant que le système conserve son efficacité. On peut y incorporer un moyen de surveillance pour s'assurer que le système reste utilisable, prolongeant ainsi la durée de service du garage. Les frais d'installation d'un système de protection cathodique sont marginalement plus élevés que ceux d'une membrane de haute qualité. Toutefois, il faut généralement assurer une protection de surface avec un système de protection cathodique. Les frais d'exploitation sont minimes, car la consommation d'électricité n'est que de 0,01 watt par pied carré de surface. On n'a pas encore publié de documentation sur l'efficacité et la durée de ces systèmes. BIBLIOGRAPHIE 1. Robinson, R.C., Cathodic Protection of Steel in Concrete, ACI Publication, SP-49, Corrosion of Metal in

Concrete. Première édition, juin 1975. 2. Slater, John E., Corrosion of Metals in Association with Concrete, American Society for Testing and

Materials, STP 818, décembre 1983. 3. Cathodic Protection of Concrete Bridge Structures, NCHRP Project 12-19, National Cooperative Highway

Research Program, septembre 1980. 4. Ward, P.M., Cathodic Protection : A User's Perspective, American Society for Testing and Materials, STP

629, juin 1977, p. 1-4.

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ANNEXE 2B Publications relatives aux réparations des structures de garage 1. ACI Committee 222 "Corrosion of Metals in Concrete", ACI Journal, janvier-février 1986, p. 3-32. 2. ACI Committee 362 "State-of-the-Art Report on Parking Structures", ACI Journal, juillet-août 1985, p. 544-

578. 3. "Back-To-The-Basics Repair of Concrete", Seminar Course Manual, SCM-13 (86), ACI, 1986. 4. "Parking Structures" ACI Compilation No. 3, C-3, 1980. 5. "Design of Concrete Parking Structures", ACI, SCM 12-86, 1986. 6. "Concrete Repair Restoration", ACI Compilation No. 5, C-5, 1986. 7. "Structural Repair - Corrosion Damage and Control", ACI, SCM 8-85, 1985. 8. "Interim Guidelines, Investigation, Repairs, Design and Construction of Parking Structures", ACI - Ontario

Chapter, août 1981. 9. "Deterioration of Parking Structures: Extent, Causes, and Repair Considerations", SCHL, 1987 Sources: 1 - 7 AMERICAN CONCRETE INSTITUTE P.O. Box 19150 22400 West Seven Mile Road Detroit, Michigan, U.S.A. 48219 8 AMERICAN CONCRETE INSTITUTE - ONTARIO CHAPTER 365, rue Bloor est Bureau 1402 Toronto (Ontario) M4W 3L4 9 SOCIÉTÉ CANADIENNE D'HYPOTHæQUES ET DE LOGEMENT 682, chemin Montréal Ottawa (Ontario) K1A OP7

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CHAPITRE 3 PROCÉDÉS DE MAINTENANCE ET DE SURVEILLANCE

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3.0 PROCÉDÉS DE MAINTENANCE ET DE SURVEILLANCE 3.1 AVANT-PROPOS Le présent chapitre n'aborde que d'une manière générale les questions d'identification, de maintenance et de surveillance relatives à la prévention de la détérioration prématurée de la structure des garages non réparés ou déjà réparés, aux types de structures et à l'environnement intérieur ou extérieur. Pour les autres éléments de construction, consulter la référence 1 dans l'annexe 3A. Les définitions suivantes sont incluses: IDENTIFICATION: Avant de pouvoir surveiller un problème et/ou en assurer la maintenance, il faut d'abord savoir l'identifier. SURVEILLANCE: Se rapporte à l'inspection périodique prévue et aux observations de l'état et de l'aspect physique du garage. MAINTENANCE: Se rapporte à tous les travaux nécessaires pour maintenir la structure dans un état d'utilisation satisfaisant et empêcher la détérioration sérieuse de la dalle et des éléments de soutien du garage pouvant conduire, dans les cas extrêmes, à l'effondrement partiel de la structure. Dans un garage, la maintenance concerne essentiellement la dalle de plancher suspendue. La gravité des conditions défavorables dans les garages varie selon le lieu, la température (avec ou sans chauffage), le niveau d'humidité et la quantité de sel répandue sur les routes. En plus des conditions défavorables, l'importance de la maintenance et de la surveillance requises peut dépendre des matériaux, des méthodes et des détails de conception pour la construction ou la réparation du garage. Le dossier des garages est relativement réduit et celui des garages réparés l'est encore davantage. Le temps n'a pas encore prouvé la qualité des matériaux et des technologies. Par conséquent, une attitude prudente à l'égard de la maintenance et de la surveillance protège le capital investi dans la construction et les frais supplémentaires des réparations requises, tout en préservant l'intégrité de la structure et la sécurité du public. Une maintenance efficace peut prolonger la durée utile de la structure d'un garage. 3.2 PORTÉE 3.2.1 Types de structure Avant de déterminer les problèmes de maintenance dans une structure, il faut identifier, en termes généraux, le type de cette structure. Cette identification est importante quand on essaie d'évaluer l'importance des divers problèmes. En effet, un problème de maintenance bénin dans un type de structure peut être grave dans une autre.

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3.2.1.1 Béton armé coulé en place En Ontario, la plupart des structures, particulièrement les garages souterrains, sont en béton armé coulé en place. Il existe de nombreuses catégories intermédiaires de ce type de structure, comme la dalle plaque, la dalle plate et la dalle gaufrée. Si l'on connaît la catégorie intermédiaire, il faut la noter. 3.2.1.2 Structures postcontraintes Les structures postcontraintes sont construites en béton coulé en place, mis en tension après qu'il a atteint la résistance voulue. Dans ce type de structure, les filins d'acier des tendons peuvent être ou ne pas être liés au béton. 3.2.1.3 Structures précontraintes Les structures précontraintes se composent d'éléments préfabriqués comportant des filins d'acier préalablement mis en tension, noyés dans le béton et liés à celui-ci. Après le durcissement du béton, on élimine la force de tension appliquée à l'extérieur; il en résulte une tension imposée à l'élément préfabriqué. Les structures précontraintes comprennent habituellement un recouvrement de béton coulé en continu. 3.2.1.4 Structures en acier Les structures en acier se composent de colonnes et de poutres d'acier assemblées sur place, qui soutiennent une dalle de plancher en béton coulé. 3.2.2 Résumé des problèmes 3.2.2.1 Drainage Les pentes de drainage insuffisantes ou les drains bouchés soumettent la dalle à une saturation prolongée, qui cause l'écaillement, la désagrégation, l'effritement ou le suintement. Le gel des flaques d'eau peut être dangereux. 3.2.2.2 Fissures Les fissures dans les éléments de béton (planchers, toits, murs, colonnes ou poutres) peuvent venir de nombreux facteurs, mais elles ne sont pas forcément préjudiciables pour la structure. Les fissures qui laissent pénétrer

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l'humidité et le sel dans la dalle sont cependant dommageables. Les fissures larges qui se forment en certains points ou qui deviennent plus nombreuses, plus larges ou plus longues, peuvent indiquer un grave problème de structure. Les fissures dans les structures postcontraintes ou précontraintes peuvent avoir plus d'importance que dans le béton armé coulé en place. Il faut faire examiner les fissures suspectes par un ingénieur en béton armé.

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3.2.2.3 Écaillement L'écaillement est le craquellement ou la désintégration de la face supérieure de la dalle de béton. L'écaillement du béton provient de l'action du gel et du dégel sur le béton mouillé ou de la saturation prolongée résultant des flaques d'eau. L'écaillement finit par pénétrer le béton en profondeur et exposer le granulat. 3.2.2.4 Effritement L'effritement peut se produire à la surface de tout élément de béton, mais il endommage surtout la face supérieure des dalles de béton. Dans les structures de garage, l'effritement provient surtout d'une fracture plane ou "désagrégation" au niveau de l'acier d'armature, causée par la corrosion saline de l'acier. La fissuration des dalles de béton peut également permettre l'infiltration de l'humidité et du sel jusqu'au-dessous des dalles; il en résulte la désagrégation et l'effritement du plafond. Ce phénomène peut se rencontrer partout en présence d'un dépôt d'eau et de sel, comme au pied des colonnes et des murs, ainsi que sur les bords d'appui des joints de dilatation qui suintent. Il faut enlever les morceaux de béton effrités qui restent accrochés, car ils constituent un danger. 3.2.2.5 Suintement, lixiviation et taches de rouille Le suintement de l'eau à travers les éléments de béton peut corroder l'armature d'acier et produire des taches de rouille sur les surfaces en béton ou la lixiviation des composants du ciment, laissant une pellicule blanche ou des stalactites du côté plafond des dalles. 3.2.2.6 Joints de dilatation Les joints de dilatation sont des désolidarisations spécifiques placées dans les dalles de béton pour en permettre le mouvement. L'inspection des joints doit se faire par le dessus, qui est leur coté accessible, afin de repérer les ruptures du scellant ou la détérioration des parties voisines en béton. La lixiviation ou des taches de rouille sur le plafond trahissent également une infiltration d'eau. On doit inspecter les bords d'appui ou les poutres pour y chercher les traces d'effritement, pouvant provenir de la corrosion de l'armature, comme on l'indique dans la section 3.2.2.4, ou de forces de friction créées par les mouvements thermiques saisonniers et l'absence de matériau antifriction entre le bord d'appui et la dalle portée. L'effritement causé par ce phénomène peut se reproduire tous les hivers. Cette fois encore, il faut enlever les morceaux effrités de béton qui restent accrochés. 3.2.2.7 Joints de controle et de construction On pratique les joints de controle dans le béton non durci pendant le processus de construction ou on les taille

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immédiatement à la scie dans le béton durci, pour controler le retrait normal. Ce joint crée un plan de faiblesse qui cause une fissure sous le joint. On applique ensuite un scellant dans le joint.

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Le joint de construction forme la liaison entre deux coulées voisines de béton, pendant la construction. Ce joint est souvent scellé contre l'infiltration par un arrêt d'eau en caoutchouc qui chevauche le joint à mi-hauteur; on peut aussi scier et sceller la face supérieure, comme avec le joint de controle. 3.2.2.8 Appareils électriques Il faut chercher les traces de corrosion ou de suintement d'eau aux appareils électriques installés du côté plafond des dalles. Le suintement de l'eau aux appareils électriques peut indiquer des problèmes d'infiltration dans les éléments de structure, en particulier dans les toits des garages souterrains. L'eau dans les canalisations ou les appareils électriques peut causer des courts-circuits. 3.2.2.9 Membranes imperméables et couches de roulement Il faut chercher les traces de fissures, de déchirures, d'usure, de décollage ou d'écaillement dans les systèmes de couche de roulement en ciment ou en élastomère. Les dommages de la membrane, sous une couche de roulement de dalle, ou sur un toit ou un mur de garage souterrain, ne sont pas visibles, mais ils peuvent être révélés par le suintement, les taches ou la lixiviation sur la surface du béton. 3.2.2.10 Acier d'armature exposé Quand l'acier d'armature est exposé, sur la surface d'une dalle, sur un plafond, un mur, une colonne, un rebord ou une poutre, on doit consulter un ingénieur en béton armé, car il y a risque de problème de structure grave. 3.2.2.11 Structures postcontraintes Quand la détérioration commence dans les structures postcontraintes, elle peut progresser plus rapidement que dans les structures en béton armé coulé en place. Il faut analyser immédiatement l'écaillement, le suintement, la lixiviation, les taches, l'effritement et les fissures. La postcontrainte a tendance à réduire les fissures. De ce fait, la présence de fissures dans une structure postcontrainte peut être plus grave que dans le béton armé coulé en place. Il faut noter les taches de rouille sur les surfaces de béton aux points d'ancrage ou de tension (comme aux extrémités des dalles). Il faut consulter un ingénieur en béton armé pour évaluer l'importance des signes de détérioration. 3.2.2.12 Structures précontraintes Les problèmes des structures précontraintes se rattachent davantage aux joints et aux raccords qu'à la corrosion

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accélérée de la dalle par le sel. Il faut noter les taches et les traces de suintement à tous les joints, aux raccords, en particulier dans les sections porteuses, et chercher les traces de défaillances physiques, notamment la fissuration et l'effritement du béton voisin.

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3.2.2.13 Structures d'acier En plus de la recherche des fissures, du suintement, des taches, de la lixiviation et de l'effondrement dans les éléments de béton, on doit aussi repérer les signes de défaillance dans les éléments d'acier. Il faut se concentrer sur les fissures, le fléchissement anormal, la déformation ou l'affaissement des éléments d'acier ou de parties de ces éléments comme les membrures et âmes de poutre, ainsi que la détérioration des agents anticorrosion, comme la peinture ou la galvanisation. Il faut aussi chercher les signes de défaillance aux raccordements soudés, boulonnés et rivetés. On encourage les propriétaires de garages à établir un budget à l'avance pour faire face aux frais de réparation possibles. Par exemple, en Ontario, la loi sur les copropriétés exige la création d'un "fonds de réserve" pour les réparations importantes et le remplacement des éléments courants. Les réparations des structures de garage entrent dans cette catégorie. Il existe malheureusement de nombreux cas de réparations importantes nécessaires dans des garages de copropriété pour lesquelles n'existait pas un fonds de réserve suffisant. Cet état de choses a motivé une répartition spéciale de frais de plusieurs centaines de dollars et, dans quelques cas, de plusieurs milliers de dollars entre les copropriétaires. Si une structure a déjà fait l'objet d'une remise en état importante, il faut quand même établir un fonds de réserve. Il n'est pas toujours nécessaire de faire les réparations dans le cadre d'un seul contrat. En raison de considérations techniques et/ou financières, on échelonne souvent les réparations sur plusieurs années, mais quelle que soit leur durée, un fonds de réserve suffisant amortit les charges financières. L'aspect financier continu de la surveillance et de la maintenance doit aussi se rattacher aux considérations économiques décrites dans l'avant-propos du chapitre 2 (Méthodes de réparation). 3.3 MÉTHODES DE SURVEILLANCE La surveillance doit faire partie intégrante des programmes de maintenance et de réparation, afin de garantir la sécurité publique et de maintenir l'intégrité de la structure d'un garage. On peut surveiller l'état d'un garage par des rondes régulières d'inspection. L'observateur consciencieux chargé de l'inspection doit noter les drains de plancher bouchés, la détérioration des faces supérieure et inférieure des dalles de toit et de plancher ainsi que le suintement ou les taches d'eau aux plafonds ou aux murs, les fissures dans les planchers, les poutres, les colonnes ou les murs et la rouille de l'acier exposé. Il doit noter les anomalies sur les plans des étages. On peut initialement s'assurer les services d'un professionnel pour procéder à un examen de l'état de la structure. La fréquence et l'importance de la surveillance dépendent de l'état du garage, des considérations économiques et des capacités du personnel en place. Il faut considérer comme un minimum les fréquences recommandées pour ces rondes d'inspection.

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3.3.1 Drainage Deux fois par mois, il faut inspecter tous les drains de plancher et toutes les pompes de puisard, pour s'assurer qu'ils sont en bon état de fonctionnement et qu'ils ne sont pas obstrués par des débris. On doit assécher les flaques d'eau et noter leur emplacement sur le plan, pour l'installation éventuelle de drains. 3.3.2 Dalles de plancher 3.3.2.1 Dalles non protégées Tous les ans (de préférence au printemps), vérifier et noter l'étendue et l'emplacement des fissures superficielles, de l'effritement du béton, de l'écaillement de surface, des ronds d'armature exposés, des taches de rouille ou du suintement au plafond. 3.3.2.2 Dalles suspendues protégées Pour les dalles avec membrane de protection, on recommande de vérifier chaque printemps l'état de la surface de roulement et de noter les parties usées, fendillées, décollées ou boursouflées de la membrane. Pour les dalles avec scellant de protection, on recommande une vérification annuelle pour localiser les parties fendillées ayant besoin d'une nouvelle application de scellant. Il faut inspecter le dessous des poutres et des dalles et noter l'emplacement et l'importance des fissures, du suintement ou des taches d'eau, des taches de rouille ou des éléments d'armature exposés. Une progression notable des dommages déjà notés peut indiquer la nécessité d'une inspection plus poussée par un ingénieur-conseil. 3.3.3 Dalles de toit Il faut inspecter le dessous des poutres et des dalles et noter l'importance et l'emplacement des fissures, du suintement ou des taches d'eau, des taches de rouille ou des éléments d'armature exposés. Une progression importante des dommages déjà notés peut indiquer la nécessité d'une inspection plus poussée par un ingénieur-conseil. 3.3.4 Dalles au niveau du sol

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Vérifier et noter chaque année l'emplacement des fissures ou du suintement de l'eau par les fissures ou les joints aux colonnes ou aux murs. Noter la formation de flaques d'eau.

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3.3.5 Joints Joints de dilatation. Vérifier les dommages et la détérioration de ces joints tous les ans, au printemps. Pour les joints remplis d'un matériau souple, noter l'emplacement et l'état de ce matériau et, en cas de fuite, prévoir la réparation ou le remplacement, conformément aux recommandations du fabricant. Prendre également note des dommages ou de la détérioration des rebords d'appui. Joints de controle. Vérifier les dommages, les détériorations ou les fuites de ces joints tous les ans, au printemps. Noter l'emplacement et l'état du matériau de joint. S'il y a lieu, faire les réparations ou remplacer les joints, conformément aux recommandations du fabricant. Joints de construction. Vérifier ces joints tous les ans, au printemps, pour s'assurer qu'ils ne fuient pas. En cas de suintement ou de taches d'eau, faire immédiatement les réparations. 3.3.6 Murs et colonnes Une fois par an, chercher les fissures, suintements, taches d'eau ou de rouille, ronds d'armature exposés, désagrégation du béton ou dommages causés par les véhicules sur les murs et les colonnes. Noter toutes les défaillances sur les plans. Si ces défaillances s'étendent notablement, on doit retenir les services d'un ingénieur-conseil qualifié. 3.3.7 Surveillance électronique A l'heure actuelle, on met au point et on essaie une nouvelle technologie s'appuyant sur les dispositifs à microprocesseur. Le propriétaire et l'exploitant de garage doivent se tenir au courant de ces réalisations. 3.4 ENTRETIEN COURANT 3.4.1 Propreté 3.4.1.1 Balayage Le balayage mécanique ou manuel d'un garage est nécessaire pour ramasser la saleté, les détritus et le sel cristallisé venant des routes en hiver. On doit enlever les accumulations de graisse et d'huile à l'aide d'un agent de dégraissage non corrosif. Le balayage régulier contribue à la propreté des drains de plancher et limite la pénétration des

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chlorures dans les dalles de béton. On doit toujours balayer les dalles avant tout lavage à grande eau. Il faut s'assurer que le poids des balayeuses mécaniques ne dépasse pas la capacité de charge des dalles de plancher.

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3.4.1.2 Lavage On peut laver les dalles à la lance à basse pression, pour en enlever la poussière et le sel des routes dissous ou non dissous. En balayant régulièrement en hiver, on risque toutefois de faire pénétrer les chlorures provenant de la dissolution du sel dans les fissures et les parties non protégées. 3.4.1.3 Drains de plancher Il faut nettoyer régulièrement les drains de plancher, particulièrement après le lavage. On recommande de chercher les signes de corrosion et de dommages mécaniques aux drains, car la détérioration du béton se produit fréquemment près de ces éléments. 3.4.1.4 Puisards et pompes de puisard Inspecter les puisards et en enlever les accumulations de sable et de détritus. Vérifier périodiquement le fonctionnement des pompes de puisard. 3.4.2 Entretien des surfaces de roulement Il faut vérifier deux fois par an les dalles non protégées (sans scellants ni membranes de protection) pour déceler les traces d'effritement ou de désagrégation. On peut faire des réparations provisoires pour continuer à utiliser les surfaces de roulement, mais il faut prévoir des réparations permanentes dès que possible. Pour les dalles protégées par des scellants, il faut procéder à des applications périodiques de scellants, conformément aux recommandations du fabricant. Il faut vérifier l'état de détérioration des membranes imperméables et les réparer, conformément aux spécifications du fabricant. 3.4.3 Peinture Il faut maintenir en bon état les surfaces peintes (mains-courantes, portes, fenêtres et cadres, tuyaux et autres parties métalliques), pour les protéger de la corrosion qui attaque les surfaces exposées. En particulier, il importe de peindre les éléments en acier (colonnes, poutres, renforts, etc.) de la structure d'un garage. 3.4.4 Joints Il faut procéder régulièrement à la vérification de tous les joints. La présence d'un suintement d'eau indique

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généralement la nécessité de remplacer le matériau des joints de dilatation et de controle.

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3.4.5 Remarques générales Le programme de surveillance doit se compléter des travaux d'entretien courant. Il faut encourager le personnel d'entretien à signaler les problèmes notés pendant les travaux quotidiens. Le personnel doit savoir déceler les signes de défaillance partout dans le garage. 3.4.6 Programmes et listes de vérifications Pour qu'un programme de maintenance soit efficace, il faut prévoir des travaux courants répondant aux besoins et exigences spécifiques du garage. Les listes de vérifications, semblables à celle donnée dans le "Programme de maintenance planifiée" (Tableau 3.1) suivant, sont particulièrement utiles pour établir un programme de maintenance systématique. Le "Parking Garage Maintenance Manual", préparé par le Parking Consultants Council of the National Parking Association (2000 K Street, N.W., Suite 350, Washington, D.C. 20006) contient une liste de vérifications et un programme de maintenance détaillés, que l'on recommande aux propriétaires et exploitants de garages. 3.5 ILLUSTRATIONS Les photos des pages 51 à 56 montrent les conséquences d'une mauvaise maintenance dans les garages en béton armé.

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TABLEAU 3.1 PROGRAMME DE MAINTENANCE PLANIFIÉE +)))))))))))))))0))))))))))))))))))))))))))))))))))))))0)))))))))))))))))))))))))), * * * * * ARTICLE * POINTS A VÉRIFIER * MESURES A PRENDRE * * * * * /)))))))))))))))3))))))))))))))))))))))))))))))))))))))3))))))))))))))))))))))))))1 * * * * * Détecteur * Vérifier si le détecteur est * S'il ne fonctionne pas, * * d'oxyde de * alimenté et en bon état de marche. * aviser la direction. * * carbone * * * * * * * /)))))))))))))))3))))))))))))))))))))))))))))))))))))))3))))))))))))))))))))))))))1 * * * * * Ventilateurs * Vérifier si les ventilateurs sont * S'ils ne fonctionnent * * * en bon état de marche. * pas, aviser la direction.* * * * * /)))))))))))))))3))))))))))))))))))))))))))))))))))))))3))))))))))))))))))))))))))1 * * * * * Appareils * Vérifier les ampoules de tous les * Aviser le personnel * * d'éclairage * appareils d'éclairage. Verifier * d'entretien de * * * s'il n'y a pas de suintenment d'eau * l'emplacement de tout * * * sur les appareils d'éclairage ou à * problème. * * * proximité. * * * * * * /)))))))))))))))3))))))))))))))))))))))))))))))))))))))3))))))))))))))))))))))))))1 * * * * * Nettoyage et * Vérifier s'il y a des détritus ou * Balayer, frotter et * * balayage * des taches d'huile ou de graisse * enlever l'huile et la * * * sur les dalles impermèabilisèes. * graisse. * * * * * /)))))))))))))))3))))))))))))))))))))))))))))))))))))))3))))))))))))))))))))))))))1 * * * * * Nettoyage * Vérifier toutes les surfaces de * Balayer et nettoyer * * mécanique * stationnement, les allées et les * régulièrement toutes les * * * rampes. Les détritus et le sel * surfaces à la machine. * * * tombant des véhicules s'accumulent * La fréquence de balayage * * * sur les dalles et les rampes. * et de nettoyage dépend * * * * de l'usage (c.-à-d. du * * * * degré d'accumulation de * * * * poussière, de sel, de * * * * sable et de détritus). * * * * * /)))))))))))))))3))))))))))))))))))))))))))))))))))))))3))))))))))))))))))))))))))1 * * * * * Flaques d'eau * Vérifier et noter les points où se * Évacuer l'eau par le * * * trouvent les flaques d'eau. * drain le plus proche. * * * * Aviser la direction pour * * *

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* l'installation possible * * * * d'un drain. * * * * * .)))))))))))))))2))))))))))))))))))))))))))))))))))))))2))))))))))))))))))))))))))-

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TABLEAU 3.1 PROGRAMME DE MAINTENANCE PLANIFIÉE (suite) +)))))))))))))))))0))))))))))))))))))))))))))))))))))))0)))))))))))))))))))))))))), * * * * * ARTICLE * POINTS A VÉRIFIER * MESURES A PRENDRE * * * * * /)))))))))))))))))3))))))))))))))))))))))))))))))))))))3))))))))))))))))))))))))))1 * * * * * Drains et pompe * S'assurer que les drains ne sont * Demander au personnel * * de puisard * pas bouchés par les détritus. * d'entretien de nettoyer * * * Vérifier le fonctionnement * les drains. Aviser le * * * de la pompe de puisard. * personnel d'entretien si * * * * la pompe ne fonctionne * * * * pas. * * * * * /)))))))))))))))))3))))))))))))))))))))))))))))))))))))3))))))))))))))))))))))))))1 * * * * * Drains de * S'assurer que les drains de * Nettoyer les drains de * * rigoles * rigoles aux entrées, etc., sont * rigoles et les rincer à * * * propres. * l'eau si nécessaire. * * * * * /)))))))))))))))))3))))))))))))))))))))))))))))))))))))3))))))))))))))))))))))))))1 * * * * * Rampes et * Vérifier, sur la face supérieure * Noter tous les défauts * * dalles * les fissures, l'usure ou * sur les plans. Si elles * * suspendues * l'effritement du béton, les * sont importantes, aviser * * non protégées * éléments d'armature exposés et les * la direction pour * * * scellants endommagés dans les * l'inspection par un * * * fissures ou joints de dilatation. * ingénieur-conseil. * * * Vérifier les fissures et le * * * * suintement sur la face inférieure. * * * * * * /)))))))))))))))))3))))))))))))))))))))))))))))))))))))3))))))))))))))))))))))))))1 * * * * * Rampes et * Vérifier sur la surface de * Noter tous les défauts * * dalles * roulement, l'usure, les fissures, * sur les plans. S'ils * * suspendues * l'écaillement et le boursouflage. * sont importants, aviser * * impermé- * Vérifier l'état du scellant des * la direction pour * * abilisées * joints de dilatation. Vérifier * l'inspection par un * * * le suintement, les taches de * ingénieur-conseil. * * * rouille ou les éléments d'amarture * * * * exposés sur la face inférieure. * * * * * * /)))))))))))))))))3))))))))))))))))))))))))))))))))))))3))))))))))))))))))))))))))1 * * * * * Murs et * Vérifier les fissures, les * Noter tous les défauts * * colonnes * éléments d'armature exposés * sur les plans. S'ils *

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* * ou le suintement sur les murs. * sont importants, aviser * * * Vérifier les taches de rouille, * la direction pour * * * l'écaillement ou les éléments * l'inspection par un * * * d'armature exposés sur les * ingénieur-conseil. * * * colonnes. * * * * * * .)))))))))))))))))2))))))))))))))))))))))))))))))))))))2))))))))))))))))))))))))))- TABLEAU 3.1 PROGRAMME DE MAINTENANCE PLANIFIÉE (suite) +)))))))))))))))))0))))))))))))))))))))))))))))))))))))0)))))))))))))))))))))))))), * * * * * ARTICLE * POINTS A VÉRIFIER * MESURES A PRENDRE * * * * * /)))))))))))))))))3))))))))))))))))))))))))))))))))))))3))))))))))))))))))))))))))1 * * * * * Dalles et * Vérifier les fissures des dalles * Noter l'emplacement des * * rampes au * aux colonnes et le suintement * fissures et du * * niveau du sol * par les fentes autour des * suintement. S'ils sont * * * colonnes et aux raccordements * importants, aviser la * * * entre dalles et les murs. * direction pour * * * * l'inspection par un * * * * ingénieur-conseil. * * * * * /)))))))))))))))))3))))))))))))))))))))))))))))))))))))3))))))))))))))))))))))))))1 * * * * * Peinture * Vérifier les garde-fous, * Retoucher le métal exposé* * * mains-courantes et tuyauteries. * avec de la peinture. * * * Vérifier les lignes peintes dans * Aviser la direction quand* * * le garage pour diriger la * la peinture des lignes * * * circulation ou le stationnement. * peintes de la dalle de * * * Rechercher les taches de rouille * plancher pèle. * * * sur les pièces en métal. * * * * * * .)))))))))))))))))2))))))))))))))))))))))))))))))))))))2))))))))))))))))))))))))))-

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ILLUSTRATION 3.1 Suintement d'eau par une fissure dans le coté plafond de la dalle.

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ILLUSTRATION 3.2

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Suintement d'eau par la dalle de toit du garage.

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ILLUSTRATION 3.3 Suintement d'eau par la dalle suspendue.

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ILLUSTRATION 3.4 Formation d'une flaque d'eau à la base d'une colonne.

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ILLUSTRATION 3.5 Effritement d'une dalle de plancher avec acier d'armature exposé et corrodé.

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ILLUSTRATION 3.6 Effritement à la base d'une colonne avec acier d'armature exposé et corrodé.

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ILLUSTRATION 3.7 Effritement du bord d'appui au joint de dilatation avec acier d'armature exposé.

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ILLUSTRATION 3.8 Filins de câble de postcontrainte corrodés et brisés.

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ANNEXE 3A 1. Parking Garage Maintenance Manual, prepared by the Parking Consultants Council, National Parking

Association. 2. Deterioration of Parking Structures: Extent, Causes and Repair Considerations (Sec. 5.0). Préparé pour la

SCHL. 3. Parking Structure Deterioration: A survey and analysis of its extent and influencing factors. Préparé pour la

SCHL, Sec. 4.0. 4. Norme Acnor S413-87 Durable Parking Structures, Appendix D.

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