CORROSION ASSESSMENT AND CONCRETE DELAMINATION SURVEY

CENTRO JUDICIAL DE AGUDILLA

AGUADILLA, PUERTO RICO

Prepared for:

HON. SIGFRIDO STEIDEL ADMINISTRATIVE DIRECTOR AT COURT OFFICE

April 22, 2021

Prepared by: SPEC GROUP, PSC.

URB SAN FRANCISCO #141 DE DIEGO AVE San Juan, Puerto Rico 00927

Tel. 787.979.9440 / 787.722.2338 / 787.502.6639 e-mail: pfebo@specengpr.com; rmarte@specengpr.com

B5 Calle Tabonuco Suite 216 PMB 278 Guaynabo, PR 00968-3022 – Ave De Diego Urb. San Francisco #141, San Juan, PR 00921 Tel (787) 502-6639 - (787) 226-5778 – (787)-722-2338 - e-mail: pfebo@specengpr.com – rmarte@specengpr.com

LABORATORY REPORT LR-2021-30 April 22, 2021 Hon. Sigfrido Steidel Atn. Eng. Maria A. Burgos Administrative Director at Court Office Via Emaail: maría.burgos@ramajudicial.pr

Re: CORROSION ASSESSMENT and CONCRETE DELAMINATION SURVEY for CENTRO JUDICIAL DE AGUADILLA

AGUADILLA, PUERTO RICO SPEC GROUP PROJECT No.: SG2021-610 Dear Engr. Burgos: This report presents the results of the Concrete Corrosion Assessment and Delamination Survey from the Parking Building Roof Slab and South Section of the Main Building Roof Slab (Centro Judicial), located in Aguadilla, Puerto Rico. The work was performed as stated on Spec Group Proposal PL-2020-84 (Revision 2), to obtain provide factual information on the corrosion condition of the structure for evaluation by Héctor Lavergne, PE (Corrosion Specialist and Consultant). For details of the areas investigated, please refer to Figures and Photos, enclosed.

To accomplish the above, SPEC GROUP performed the following work:

1. Carbonation Extent Determination by the use of Phenolphthalein Solution,

2. Determination of Concrete Chloride Content per ASTM C1218 – Standard Test Method for Water-Soluble Chloride in Mortar and Concrete, and Concrete pH Content Determination,

3. Corrosion potential survey following the guidelines of ASTM C876 – Standard Test Method for Half-Cell Potentials of Uncoated Reinforcing Steel in Concrete.

The results of the testing program performed are presented below:

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1. Determination of carbonation extent of concrete at selected locations by application of a phenolphthalein solution

Penetration of carbonation was determined by use of a phenolphthalein solution on the selective areas UNDERSIDE of the ROOF SLAB and PERIMETER WALLS of the PARKING STRUCTURE, and on CONCRETE BEAMS AND JOIST AT THE SIXTH LEVEL ROOF OF THE MAIN BUILDING in the CENTRO JUDICIAL DE AGUADILLA. When the clear phenolphthalein indicator solution comes in contact with uncarbonated cement paste, it turns pink. If the paste is carbonated, the solution will remain clear. In general, the test results disclosed that the structure shows evidence of carbonation extent on the mentioned areas at the time of our tests. The test results disclosed that the Carbonation depth varies from 0.00” to about 2.00”.

Typical Concrete Carbonation Test

Figure 1: Typical Concrete Carbonation Behavior

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Table 1: Carbonation Extent

Carbonation Testing Results

Sample ID Element Level Location Carbonation Extent (in)

C – 1 Slab Ground Bottom 0.50 from underside surface

C – 2 Wall Basement South Side 1.00 from underside surface

C – 3 Slab Ground Bottom 1.25 from underside surface

C – 4 Wall Basement South Side 1.50 from underside surface

C – 5 Slab Ground Bottom 0.00 from underside surface

C – 6 Slab Ground Bottom 1.50 from underside surface

C – 7 Slab Ground Bottom 1.75 from underside surface

C – 8 Slab Ground Bottom 1.50 from underside surface

C – 9 Slab Ground Bottom 1.25 from underside surface

C – 10 Slab Ground Bottom 1.125 from underside surface

C – 11 Slab Ground Bottom 0.75 from underside surface

C – 12 Slab Ground Bottom 0.50 from underside surface

C – 13 Slab Ground Bottom 1.00 from underside surface

C – 14 Slab Ground Bottom 1.00 from underside surface

C – 15 Wall Basement East Side 1.75 from underside surface

C – 16 Wall Basement East Side 1.25 from underside surface

C – 17 Slab Ground Bottom 1.75 from underside surface

C – 18 Slab Ground Bottom 1.75 from underside surface

C – 19 Slab Ground Bottom 1.25 from underside surface

C – 20 Slab Ground Bottom 1.00 from underside surface

C – 21 Slab Ground Bottom 1.50 from underside surface

C – 22 Slab Ground Bottom 1.25 from underside surface

C – 23 Slab Ground Bottom 1.00 from underside surface

C – 24 Slab Ground Bottom 1.00 from underside surface

C – 25 Slab Ground Bottom 1.50 from underside surface

C – 26 Wall Basement East Side 1.00 from underside surface

C – 27 Slab Ground Bottom 2.00 from underside surface

C – 28 Slab Ground Bottom 1.00 from underside surface

C – 29 Rib Beam Roof Bottom 0.00 from underside surface

C – 30 Joist Roof Bottom 2.00 from underside surface

C – 31 Joist Roof Bottom 2.00 from underside surface

C – 32 Joist Roof Bottom 1.00 from underside surface

C – 33 Joist Roof Bottom 2.00 from underside surface

C – 34 Primary Beam Roof Bottom 1.00 from underside surface

C – 35 Joist Roof Bottom 1.50 from underside surface

C – 36 Primary Beam Roof Bottom 1.00 from underside surface

C – 37 Joist Roof Bottom 1.00 from underside surface

C – 38 Joist Roof Bottom 1.00 from underside surface

The carbonation extent was performed by using phenolphthalein solution

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2. Determination of Water-Soluble Chloride Ion (Cl-) Content and pH Eleven (11) samples were secured from the slab at different locations, for laboratory determination of water-soluble chloride ion (Cl-) content and pH. The results are presented in Table 2 below:

Table 2: Water-Soluble Ion and pH Content

Sample No.

Building Level Element Elem.

Location Grid Loc

pH Chloride Ion Content (Cl-)

(by wt. of cement)

CL – 1 Parking Ground Slab Bottom A, B &

1, 2 9.6 0.71

CL – 2 Parking Ground Slab Bottom C, D &

2, 3 10.1 0.34

CL – 3 Parking Ground Slab Bottom C, D &

4, 5 10.7 0.39

CL – 4 Parking Ground Slab

Bottom D & 4, 5

10.2 0.08

CL – 5 Parking Ground Slab

Bottom D

& 7, 8 10.9 0.34

CL – 6 Parking Basement Wall East Face

A & 4, 5

9.2 0.32

CL – 7 Parking Basement Wall East Face

A & 8, 9

11.2 1.68

CL – 8 Main

Tower Roof

Primary Beam

Bottom C, D & 2, 2’

9.2 0.67

CL – 9 Main

Tower Roof

Conc. Joist

Bottom B, C & 1, 1’

9.3 0.20

CL – 10 Main

Tower Roof

Rib Beam

Bottom A’, A &

1, 1’ 10.7 0.02

CL – 11 Main

Tower Roof

Conc. Joist

Bottom C, D & 1, 1’

10.9 0.13

The water-soluble chloride ion (Cl-) content tests performed on the samples secured disclosed a water-soluble chloride ion content by weight of cement ranging from 0.02% to 1.68%. The pH tests performed disclosed values ranging from 9.2 to 11.2.

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3. Determination of the corrosion potential of the steel-in-concrete by means of a corrosion activity survey was conducted using a copper-copper sulfate reference cell

Corrosion surveys of the steel-in-concrete are made by measuring the voltage potential between the steel and its electrolyte (concrete) using a copper-sulfate reference electrode. The voltage potential measurement provides an indication of the corrosion activity of the steel-in-concrete at the time of the measurement. This method has been used extensively in USA to determine corrosion activity of steel-in-concrete in pavements, bridge structures and buildings affected by salts used for deicing of highways or subject to marine environments, moisture and other corrosion inducing materials (salt spray). Its use has been proven effective in the detection of corrosion activity and is widely used by the Federal Highway Administration.

Voltage potentials numerically lower than -0.20 V CSE correspond to a greater than 90% probability that reinforcing steel corrosion is not occurring in that area at the time of the measurement. Measurements in the range of -0.20 to -0.35 V CSE correspond to an uncertain corrosion activity in that area at the time of measurement.

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Finally, measurements, numerically greater than -0.35 V CSE correspond to a greater than 90% probability that corrosion on reinforcing steel is occurring in that area at the time of the measurement. The results of our survey are provided below in Table 3.

Table 3: Corrosion Potential Measurements

Surveyed Area

Potential Measurements, Numerically Numerically Lower than -0.20 V CSE

Bet. -0.20 and

-0.35 V CSE

Numerically Greater than -0.35 V CSE

Parking Structure at Ground Slab Underside

P1 – GRID A TO F & 9,10 48 0 0

P2 – GRID A TO F & 8, 9 120 0 0

P3 – GRID A TO F & 7, 8 60 0 0

P4 – GRID A TO F & 6, 7 60 0 0

P5 – GRID A TO F & 5, 6 120 0 0

P6 – GRID A TO F & 4, 5 60 0 0

P7 – GRID A TO F & 3, 4 58 2 0

P8 – GRID A TO F & 2, 3 119 1 0

P9 – GRID A TO F & 1, 2 59 1 0

TOTAL PARKING STRUCTURE READINGS = 708

Main Tower Building at Roof Joist & Beams Underside

P10 – GRID 1 TO 2’ & C, D 66 4 0

P11 – GRID 1 TO 1’ & B, C 64 1 0

P12 – GRID 1 TO 1’ & A, B 54 0 1

TOTAL MAIN BUILDING READINGS = 190

Summary: PARKING STRUCTURE – UNDERSIDE GROUND SLAB Ninety nine percent (99 %) of the readings (704 readings) obtained, were numerically lower than -0.20 V CSE, corresponding to a greater than 90% probability that reinforcing steel corrosion is not occurring in that area at the time of the measurement.

One percent (1 %) of the readings (4 readings) obtained were in the range of -0.20 to -0.35 V CSE, corresponding to an uncertain corrosion activity in that area at the time of measurement.

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Zero percent (0 %) of the readings (0 readings) obtained were numerically lower than -0.35 V CSE, corresponding to a greater than 90% probability that reinforcing steel corrosion is occurring in that area at the time of the measurement.

MAIN BUILDING – UNDERSIDE ROOF BEAMS & JOIST Ninety seven percent (97%) of the readings (184 readings) obtained, were numerically lower than -0.20 V CSE, corresponding to a greater than 90% probability that reinforcing steel corrosion is not occurring in that area at the time of the measurement.

Two percent (2%) of the readings (5 readings) obtained were in the range of -0.20 to -0.35 V CSE, corresponding to an uncertain corrosion activity in that area at the time of measurement. One percent (1%) of the readings (1 reading) obtained were numerically lower than -0.35 V CSE, corresponding to a greater than 90% probability that reinforcing steel corrosion is occurring in that area at the time of the measurement.

4. Concrete Delamination Determination Survey A delamination survey was conducted following the requirements of ASTM D4580, “Standard Practice for Measuring Delaminations in Concrete Decks by Sounding. The equipment used for the delamination survey was a combination of the Hammer Method and Rotary Percussion. The Hammer produces a clear ringing sound, when tapped over non-delaminated concrete and a dull or hollow sound over delaminated concrete. The Rotary Percussion Sounding Device is a “T” shaped device with two rotary percussion units, which spin when rolled over a concrete surface. As the rotary percussion-sounding device is rolled over the surface, the two percussion units strike the surface with sufficient force to create a clear ringing sound, when tapped over non-delaminated concrete and a dull or hollow sound over delaminated concrete. Table 4 presents the result of the delamination in tabulated for. The survey disclosed, in general, that about 1,156 ft2 of the exposed concrete surfaces were delaminated. Additional data are included in the drawings and photos enclosed in the Appendices A and C of this technical report.

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Table 4: Concrete Delamination Survey

Delamination ID#

Delamination Location Info Delamination Dimensions Info

Level Element Element Loc Length

(ft) Width

(ft) Total

Area (ft2) 1 Ground Slab Bottom 9.17 1.00 9.17 2 Ground Slab Bottom 2.50 1.00 2.50 3 Ground Slab Bottom 1.50 1.50 2.25 4 Ground Slab Bottom 1.00 1.00 1.00 5 Ground Slab Bottom 1.00 1.00 1.00 6 Ground Slab Bottom 1.50 2.00 3.00 7 Ground Slab Bottom 1.50 2.50 3.75 8 Ground Slab Bottom 3.50 1.50 5.25 9 Ground Slab Bottom 1.00 2.00 2.00 10 Ground Slab Bottom 6.00 2.50 15.00 11 Ground Slab Bottom 1.00 2.50 2.50 12 Ground Slab Bottom 8.00 2.50 20.00 13 Ground Slab Bottom 128.00 4.50 576.00 14 Ground Slab Bottom 1.50 2.00 3.00 15 Ground Slab Bottom 1.00 1.50 1.50 16 Ground Slab Bottom 1.50 1.50 2.25 17 Ground Slab Bottom 1.50 2.00 3.00 18 Ground Slab Bottom 2.50 12.33 30.83 19 Ground Slab Bottom 2.00 1.50 3.00 20 Ground Slab Bottom 2.67 4.17 11.11 21 Ground Slab Bottom 1.00 1.50 1.50 22 Ground Slab Bottom 5.50 3.50 19.25 23 Ground Slab Bottom 1.00 1.00 1.00 24 Ground Slab Bottom 1.00 4.00 4.00 25 Ground Slab Bottom 6.67 2.00 13.33 26 Ground Slab Bottom 2.50 2.50 6.25 27 Ground Slab Bottom 3.33 1.50 5.00 28 Ground Slab Bottom 3.00 3.00 9.00 29 Ground Slab Bottom 3.00 1.00 3.00 30 Ground Slab Bottom 7.50 3.00 22.50 31 Ground Slab Bottom 1.50 3.00 4.50 32 Ground Slab Bottom 1.00 1.50 1.50 33 Ground Slab Bottom 1.00 1.50 1.50 34 Ground Slab Bottom 1.00 1.00 1.00 35 Ground Slab Bottom 2.50 2.50 6.25

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Table 4: Concrete Delamination Survey (cont.)

Delamination ID#

Delamination Location Info Delamination Dimensions Info

Level Element Element Loc Length

(ft) Width

(ft) Total

Area (ft2) 36 Ground Slab Bottom 1.00 2.00 2.00 37 Ground Slab Bottom 1.33 4.00 5.33 38 Ground Slab Bottom 1.50 1.00 1.50 39 Ground Slab Bottom 1.00 1.00 1.00 40 Ground Slab Bottom 1.00 1.50 1.50 41 Ground Slab Bottom 1.17 1.50 1.75 42 Ground Slab Bottom 5.33 4.00 21.33 43 Ground Slab Bottom 2.00 2.00 4.00 44 Ground Slab Bottom 2.00 3.83 7.67 45 Ground Slab Bottom 1.33 2.00 2.67 46 Ground Slab Bottom 1.00 1.00 1.00 47 Ground Slab Bottom 2.50 2.50 6.25 48 Ground Slab Bottom 1.00 4.33 4.33 49 Ground Slab Bottom 1.00 1.50 1.50 50 Ground Slab Bottom 1.00 1.00 1.00 51 Ground Slab Bottom 1.00 7.17 7.17 52 Ground Slab Bottom 1.00 3.33 3.33 53 Ground Slab Bottom 1.00 4.67 4.67 54 Ground Slab Bottom 1.50 3.00 4.50 55 Ground Slab Bottom 2.00 3.17 6.33 56 Ground Slab Bottom 1.00 1.00 1.00 57 Ground Slab Bottom 1.50 1.50 2.25 58 Ground Slab Bottom 4.00 4.00 16.00 59 Ground Slab Bottom 1.00 1.50 1.50 60 Ground Slab Bottom 3.50 5.00 17.50 61 Ground Slab Bottom 1.50 1.50 2.25 62 Ground Slab Bottom 1.00 1.00 1.00 63 Ground Slab Bottom 1.00 1.00 1.00 64 Ground Slab Bottom 1.00 1.50 1.50 65 Ground Slab Bottom 1.50 3.50 5.25 66 Ground Slab Bottom 2.25 2.00 4.50 67 Ground Slab Bottom 1.00 1.00 1.00 68 Ground Slab Bottom 2.00 2.00 4.00 69 Ground Slab Bottom 1.00 1.00 1.00 70 Ground Slab Bottom 1.00 1.67 1.67

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Table 4: Concrete Delamination Survey (cont.)

Delamination ID#

Delamination Location Info Delamination Dimensions Info

Level Element Element Loc Length

(ft) Width

(ft) Total

Area (ft2) 71 Ground Slab Bottom 1.00 1.00 1.00 72 Ground Slab Bottom 1.00 2.00 2.00 73 Ground Slab Bottom 1.00 2.50 2.50 74 Ground Slab Bottom 1.50 1.67 2.50 75 Ground Slab Bottom 1.00 1.50 1.50 76 Ground Slab Bottom 1.00 1.00 1.00 77 Ground Slab Bottom 1.00 1.00 1.00 78 Ground Slab Bottom 0.50 3.50 1.75 79 Ground Slab Bottom 1.00 1.00 1.00 80 Ground Slab Bottom 1.00 1.00 1.00 81 Ground Slab Bottom 3.00 1.00 3.00 82 Ground Slab Bottom 1.00 1.00 1.00 83 Basement Wall East Face VARIES* 31.00 84 Basement Wall East Face VARIES* 51.64 85 Basement Wall East Face VARIES* 16.49 86 Basement Wall East Face 1.33 12.83 17.11 87 Basement Wall East Face 1.67 2.50 4.17 88 Basement Wall East Face VARIES* 5.42 89 Basement Wall East Face 1.00 1.00 1.00 90 Basement Wall East Face 2.00 2.00 4.00 91 Basement Wall East Face VARIES* 10.42 92 Basement Wall East Face VARIES* 9.96 93 Basement Wall South Face VARIES* 13.31 94 Basement Wall South Face 2.25 2.17 4.88 95 Basement Wall South Face 1.50 1.50 2.25 96 Roof Beam Bottom 11.50 1.50 17.25

Total Delaminated Area (ft2) = 1, 156.07

5. Visual Reconnaissance/Survey of Reinforcing Steel Condition The exposed steel reinforcement was randomly observed and measured to establish the prevailing conditions, following mechanical wire brushing with electrical power equipment. It was observed in generally in good conditions (the rebar deformations were generally evident). The visually observed section loss of the steel reinforcement due to corrosion is mainly scaling and does not represent a significant LOSS of the original section.

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The diameter of the reinforcing steel of the Parking Building Roof Slab varies from 0.500” (#4 rebar) to 0.750” (#6 rebar) and the spacing varies between 6” to 10” in both directions. The concrete cover varies between 0.250” (¼”) to about 1.000” (1”), measured from the underside surface of the roof slab. The diameter of the bottom reinforcing steel of the concrete joists in the South Section of the Main Building Roof Slab consist of (2) two rebars with a diameter of 0.750” (#6 rebar) continuous. The concrete cover varies between 0.500” (½”) to about 1.000” (1”), measured from the underside surface of the concrete joist. 6. Evaluation of Tests Results and Comments A. Carbonation occurs when the calcium hydroxide portion of the paste reacts with

carbon dioxide from the atmosphere to form calcium carbonate. Accompanying this alteration is an eventual decrease in the alkalinity of the paste from its naturally high value (pH 13 and over) to near neutral (pH about 8-9). Corrosion of the steel reinforcement will be initiated when the pH values drop to a “threshold value” 10 and below, adopted by convention. The phenolphthalein tests performed disclosed that carbonation of the concrete is present throughout the Parking Building Roof Slab and the South Section of the Main Building Roof Slab of the Centro Judicial de Aguadilla. The phenolphthalein sprayed on non-carbonated would change to a pink color. The higher the alkalinity of the concrete would result in a higher intensity of the pink color. This is evident on the photos enclosed, in which the pink color is not consistent on the sprayed surfaces, which show areas lighter and darker, and even some where the phenolphthalein did not change color at all.

B. pH - Steel reinforcement in concrete in a high alkaline environment (pH values above 12) develops a “passivating” layer, which protects the steel reinforcement from corrosion. Concrete has a pH value above 12.

The drop in pH can also be caused by the penetration of water-soluble chloride ions (Cl-), which have little effect on the strength of hardened concrete, but they increase the risk/propensity/susceptibility of corrosion of the steel reinforcement. The pH tests performed disclosed values ranging from 9.2 to 11.2, which at, and below, the “threshold” value.

C. When the Water-soluble chloride ion (Cl-) concentration of the concrete exceeds

the so-called “threshold” level, which has been established by convention at about 0.2% by weight of cement, corrosion of the steel reinforcement initiates.

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The American Concrete Institute Building Code Requirements for Structural Concrete - ACI-318-14, Section 19.3, Table 19.3.2.1 – Requirements for Concrete by Exposure Class section of Maximum Water-Soluble Chloride Ion Content in Concrete, % by Weight of Cement, limits the maximum chloride ion content (by weight of cement) at 0.15% for “Concrete exposed to moisture and an external source of chloride from deicing, chemicals, salt, brackish water seawater, or spray from these sources.”

The water-soluble chloride ion (Cl-) content tests performed on the samples secured disclosed a water-soluble chloride ion content by weight of cement ranging from 0.02% to 1.68%.

D. Corrosion potential of the steel-in-concrete – the corrosion potential survey

yielded low voltage potential values, which would tend to indicate a low probability of corrosion of the reinforcing steel in the concrete occurring at the time of our fieldwork. The low values could be associated to the relatively low moisture content of the concrete in-place at the time of measurement. It would be reasonable to assume that during the wet seasons, the moisture of the concrete (electrolyte) would increase, thereby increasing the conductivity of the concrete (lowering the resistivity), and thus re-initiating the corrosion process.

E. Delamination survey - this damage is the result of the increase in volume of the reinforcing bar as corrosion occurs. This cross-sectional increase in volume acts as a wedge and delaminates (“spalls”) the surrounding concrete. The concrete cover will de-bond from the reinforcing steel and can be present as highly visible spalls, or the damaged area may remain hidden. Areas indicated to be delaminated lack structural bond between the cover and the reinforcement.

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The cracks observed on the concrete surface generally run parallel to the lower layer of the reinforcing steel matt. In general, about 1,156 ft2 of the investigated was found impacted by delamination problems. For details, refer to drawing enclosed. This represents less than 10% of the surface area of the roof, estimated at about 15,000 ft2.

F. Visual Reconnaissance/Survey of Reinforcing Steel Condition - the visual

reconnaissance of the condition of the exposed reinforcing steel Parking Building Roof Slab and the South Section of the Main Building Roof Slab disclosed apparently low loss of the cross section of the later. As indicated earlier, the exposed steel rebars were observed in surprisingly generally in good conditions (the rebar deformations were generally evident). Only in one area water a leak from the top surface of the roof slab was evident in our site visits, as shown of Photo No. 2. The visually observed section loss of the steel reinforcement due to corrosion is mainly scaling and does not represent a significant LOSS of the original section.

G. General - Corrosion is the deterioration of a substance (usually a metal) or its

properties because of a reaction with the environment. In the particular case of the steel-in-concrete, it is an electrochemical process, in which the iron in the steel is trying to return to its natural state (iron ore). Iron, in its natural state, occupies from 5 to 10 times the volume of the steel. When the expansion pressure on the concrete surrounding the steel, reinforcement exceeds the tensile capacity of the concrete, it spalls. That is why spalling occurs when the steel-in-concrete corrodes.

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Corrosion of the reinforcing steel in Portland cement concrete is nonexistent, unless an external environmental agent (such as chlorides, oxygen, etc.) upsets the normal passive state of the reinforcing steel in this alkaline environment. For corrosion to occur, there must be four components present in a corrosion cell: 1) an anode, 2) a cathode, 3) an electrical path, and 4) an electrolyte The electrolyte is the concrete, while the anode, cathode and electrical path are in the steel itself. If the pH of the electrolyte (concrete) is high, a passivating layer is created around the steel, protecting it from corrosion. Intrusion of external agents, such as chlorides and carbon dioxide from the atmosphere and through cracks, lower the pH of the concrete and destroy this passivating layer. This happens when the concrete, which is not totally impervious, is not protected properly (such and coating, application of inhibitors, etc.)

7. Conclusions and Recommendations As indicated earlier, the visual reconnaissance disclosed that the condition of the reinforcing steel in the spalled areas, although corroded, is surprisingly good and with minimal section loss. It is suspected that this is due to the relatively dry condition of the concrete. In the Parking Building Roof Slab, although exposed to open air, the concrete was observed relatively dry and with minimal water penetration (leaks) through the slab (only 1). In the South Section of the Main Building Roof Slab, the area is air conditioned, so unless the roof waterproofing system fails and the AC System is operational, the concrete should be relatively dry. Although the chemical tests on the concrete would be favorable to support the corrosion process of the reinforcing steel, the environmental conditions observed on both structural elements, would tend to minimize the electrolytic properties of the concrete, thus reducing corrosion. However, once corrosion starts, the only way to stop is by interrupting the corrosion cell, by eliminating any of the four components of the corrosion cell, as indicated above, by:

a. the installation of a Cathodic Protection System (CP), b. preparation of the areas and application of corrosion mitigation products, or c. demolition of the structure.

If the four components of the corrosion cell are present, the reinforcing steel will corrode until it disintegrates COMPLETELY.

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Based on the above, the following recommendations are provided:

a. the installation of a Cathodic Protection System (CP) – A CP System works by providing a constant current flow from artificial anodes (conductive mastic) to the cathodic zones of the reinforcing steel in the concrete, so the anodic zones areas in the reinforcing steel itself area eliminated. Hence, the corrosion of the steel is STOPPED, while the CP System is operating. The artificial anodes (conductive mastic) would be “more positive” than the anodic zones of the reinforcing steel in the concrete by the application of a continuous impressed DC Current from an external power source. Conductive mastic anodes consist of anodes embedded on the surface of concrete having a conductive coating. They are used on vertical surfaces, ceilings, and columns. The cost of an Impressed Current Cathodic Protection System (ICCP) is highly variable, depending, among others, on the location of the structure, the geometric configuration of the structure, the total area to be protected, the accessibility of the areas to be protected, etc. The total average cost of an ICCP System in the US is estimated at around $50.00/ft2, although could be higher for smaller projects. The total cost will vary depending on the provider of the system, the monitoring devices to be installed, and the service plan requested. Being a specialized system, the prospective contractors would have to request the design and cost of the ICCP System to be installed in this project. An Impressed Current Cathodic Protection System (ICCP) requires regular monitoring and comprehensive testing at least every 2-3 years.

b. preparation of the areas and application of corrosion mitigation products –

this option considers the preparation of areas to be repaired (spalled areas, whether the reinforcing steel is exposed, or not) following approved repair/rehabilitation techniques by the International Concrete Repair Institute (ICRI): Guide for Surface Preparation for the Repair of Deteriorated Concrete Resulting from Reinforcing Steel Corrosion (Guideline No. 310.1R-2008) and Guide for Selecting Application Methods for the Repair of Concrete Surfaces (320.1R-2019), , summarized below:

1. Repair/patching of deteriorated areas in Reinforced Concrete Slabs – areas to be repaired/patched should be modified to provide for simple layouts to reduce edge length and eliminate acute angles. The geometrical configuration of the repair areas should be as simple as possible, in square or rectangular pattern

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with square (90º) corners, as shown below. Reentrant corners shall be avoided. Follow ICRI the guidelines indicated earlier.

2. The perimeters of repair areas shall provide right angle cuts to the concrete surface by saw cutting. Saw cuts shall be a minimum 3/4” deep and shall be perpendicular to the surface. Do not cut existing reinforcing steel. If reinforcing steel is encountered, limit the cut depth to the top surface of the reinforcing steel. Extend demolition of concrete in spalled areas at least 6 inches into the non-corroded reinforcing steel (by visual inspection).

3. Thoroughly clean all surfaces prior to repair using high pressure washing / hydro blasting (7,000psi minimum), to remove previous coating(s)/paint, dust, loose particles, delaminated concrete, or other foreign material, which would prevent penetration of a Corrosion Inhibitor Treatment.

4. Apply a bonding agent and reinforcing steel protection material to exposed steel (use Sika Armatec® 110 EpoCem®, or similar).

5. Apply Patching Material in lifts (thickness) not exceeding 2”, as recommended by manufacturer (use SikaRepair® 223, SikaQuick® VOH, or similar), following ICRI the guidelines indicated earlier.

6. Apply a Corrosion Inhibitor Treatment to all concrete surfaces of the Parking Building Roof Slab and Walls, and the South Section of the Main Building Roof Slab, following the manufacturer’s specifications. Use Sika® FerroGuard®-908, or similar. Apply a minimum of three (3) coats, or as directed by the manufacturer’s technical representative.

PREPARE ALL SURFACES (CONCRETE AND STEEL) AND APPLY REPAIR MATERIALS FOLLOWING MANUFACTURER’S RECOMMENDATIONS. For estimating purposes, consider 1,500ft2 for the area requiring repair on the Parking Building Roof Slab and Walls, and all the concrete joists of the South Section of the Main Building Roof Slab, plus 500ft2 of the reinforced concrete beams around them. Provide an additive unit cost for additional areas.

c. The final option would be the demolition of the corroded structural elements. Finally, it is recommended that a copy of this report be provided to the prospective contractors for review.

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The selected contractor awarded the project shall prepare and submit for approval a Work Plan, which must include the materials to be used and a detailed Execution Protocol for the individual areas of the project.

8. Final Comments The undersigned warrant that the professional services performed in this Corrosion Assessment and Delamination Survey are in accordance with generally accepted principles and professional practice in the Engineering Practice. This is the only warranty, either express or implied.

THE EVALUATION OF THE INTEGRITY OF THE REINFORCED CONCRETE BUILDINGS OR THEIR STRUCTURAL ELEMENTS ARE BEYOND THE SCOPE OF THIS WORK.

The laboratory test results contained in this report are from selected and representative number of samples from the concrete structures as obtained at the time of our fieldwork. The Conclusions and Recommendations provided are based on the visual reconnaissance of the conditions of the structures as they exist at the time of our investigation and at the areas investigated. Interpretation and judgment based on these data may differ from actual conditions, since variations in the nature and behavior of subsurface materials may occur within short distances. Should any local condition found during the repair/rehabilitation work differ from those presented in this report, this firm should be immediately notified, since alternate measures may be necessary. Therefore, it is recommended that the observation of the work be observed by an engineer of this firm, or his representative. Professional Engineering services of this nature are a two-phase process. In the first phase, the Engineer advises the CLIENT about project-specific risks and a corrosion survey/exploration plan that responds to the CLIENT's risk tolerance levels, budget, schedule, and other vital concerns. The above resulted in the performance of this Corrosion Assessment and Delamination Survey, evaluation of the encountered conditions and the recommendations for the repair/rehabilitation of the structure(s). Field Observation comprises the second phase of a complete Professional Engineering service; permitting those who developed the engineering report to observe actual conditions encountered in the repair/rehabilitation of the structure(s), and thereby assess the reliability of the recommendations provided. However, actual conditions may differ from those

CENTRO JUDICIAL DE AGUADILLA Laboratory Report LR-2021-30 April 22, 2021 Page 18 of 55

expected, and that situation can create serious problems unless a qualified individual is available to decide what to do about them, where and when they are found. Decisions such as these are “judgment calls”, and the quality of judgment can have an impact on the project. Conscious of the above, it is recommended that in the event the Field Observation Phase of the work is granted to another Professional Engineering firm, they should review this report. If said firm agrees with it, it will adopt it as its own, or conduct additional work as deemed necessary thus fully relieving SPEC Group, PSC of responsibility for the project. This report was prepared specifically for the Administración de Tribunales, for the Concrete Corrosion Assessment and Delamination Survey from the Parking Building Roof Slab and South Section of the Main Building Roof Slab of the Centro Judicial de Aguadilla, in Aguadilla, Puerto Rico. It must not be used for any other project, even at this site, without the express written consent of this firm. If there are any questions, contact the undersigned at your convenience. Respectfully submitted,

PEDRO FEBO BORIA, AE ROBERTO MARTE DE LA MOTA, PE Engineer/Vice-President Engineer/President HÉCTOR LAVERGNE- RAMIREZ, PE Corrosion Consultant

CENTRO JUDICIAL DE AGUADILLA Laboratory Report LR-2021-30 April 22, 2021 Page 19 of 55

1. APPENDIX A – PHOTOS

CENTRO JUDICIAL DE AGUADILLA Laboratory Report LR-2021-30 April 22, 2021 Page 20 of 55

Photo 1: Concrete spalling underside of the ground slab at Parking Roof Structure

Photo 2: Apparent water leak

CENTRO JUDICIAL DE AGUADILLA Laboratory Report LR-2021-30 April 22, 2021 Page 21 of 55

Photo 3: Concrete joist with cracks and spalling in many areas.

Photo 4: Longitudinal rebar was found discontinued in one of the joist.

CENTRO JUDICIAL DE AGUADILLA Laboratory Report LR-2021-30 April 22, 2021 Page 22 of 55

Photo 5: Concrete of joist started to spall.

Photo 6: Cracks and spalling observed in many of the joist.

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Photo 7: Primary beam at the library area with concrete spalling and rebar exposed.

Photo 8: Cracks and spalling observed in many of the joist.

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Photo 9: Rib beams were observed without any visual deficiencies.

Photo 10: Cracks and spalling observed in many of the joist.

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Photo 21: Cracks and spalling observed in many of the joist.

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2. APPENDIX B – FIELD WORK PHOTOS

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Photo 3: Exposed rebar were used to search for continuity between rebar.

Photo 43 Corrosion potential testing performed underside the ground slab of the parking.

CENTRO JUDICIAL DE AGUADILLA Laboratory Report LR-2021-30 April 22, 2021 Page 28 of 55

Photo 5: Corrosion potential testing performed underside the ground slab of the parking.

Photo 6: Measuring clear cover and carbonation depth.

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Photo 7: Performing delamination survey with DD tool on primary beams.

Photo 8: Performing delamination survey with DD tool on rib beams.

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Photo 98: Performing continuity test between rebar on roof level of the main building.

Photo 10: Carbonation test performed at rib beams.

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Photo 20: Carbonation test performed at underside of the ground slab at parking.

Photo 11: Carbonation test performed at east face of wall in the basement at parking.

CENTRO JUDICIAL DE AGUADILLA Laboratory Report LR-2021-30 April 22, 2021 Page 32 of 55

3. APPENDIX B – CORROSION REPORTS

HALF-CELL POTENTIAL TEST Report Prepared at April 07,2021 12:56 PM

DESCRIPTION

Project Name: Centro Judicial P1Date Created: March 24,2021 10:17 AMPotential Unit: mV/CSELength Unit: ftTemperature Unit: °FTemperature Correction: OnNumber of Nodes (X): 4Node Spacing (X): 4Number of Nodes (Y): 12Node Spacing (Y): 4

SUMMARY

Measurement Range: Area(%)< -350 mV 0.0-350 mV to -200 mV 0.0> -200 mV 100.0

CORROSION POTENTIAL CONTOUR MAP

signature Report Generated by Giatec XCell™

Tabulated file in CSV format is enclosed

HALF-CELL POTENTIAL TEST Report Prepared at April 07,2021 1:03 PM

DESCRIPTION

Project Name: Centro judicial P2Date Created: March 24,2021 10:40 AMPotential Unit: mV/CSELength Unit: ftTemperature Unit: °FTemperature Correction: OnNumber of Nodes (X): 6Node Spacing (X): 4Number of Nodes (Y): 20Node Spacing (Y): 4

SUMMARY

Measurement Range: Area(%)< -350 mV 0.0-350 mV to -200 mV 0.0> -200 mV 100.0

CORROSION POTENTIAL CONTOUR MAP

signature Report Generated by Giatec XCell™

Tabulated file in CSV format is enclosed

HALF-CELL POTENTIAL TEST Report Prepared at April 07,2021 1:28 PM

DESCRIPTION

Project Name: Centro Judicial P3Date Created: March 24,2021 11:27 AMPotential Unit: mV/CSELength Unit: ftTemperature Unit: °FTemperature Correction: OnNumber of Nodes (X): 3Node Spacing (X): 4Number of Nodes (Y): 20Node Spacing (Y): 4

SUMMARY

Measurement Range: Area(%)< -350 mV 0.0-350 mV to -200 mV 0.0> -200 mV 100.0

CORROSION POTENTIAL CONTOUR MAP

signature Report Generated by Giatec XCell™

Tabulated file in CSV format is enclosed

HALF-CELL POTENTIAL TEST Report Prepared at April 07,2021 1:31 PM

DESCRIPTION

Project Name: Centro Judicial P4Date Created: March 24,2021 11:43 AMPotential Unit: mV/CSELength Unit: ftTemperature Unit: °FTemperature Correction: OnNumber of Nodes (X): 3Node Spacing (X): 4Number of Nodes (Y): 20Node Spacing (Y): 4

SUMMARY

Measurement Range: Area(%)< -350 mV 0.0-350 mV to -200 mV 0.0> -200 mV 100.0

CORROSION POTENTIAL CONTOUR MAP

signature Report Generated by Giatec XCell™

Tabulated file in CSV format is enclosed

HALF-CELL POTENTIAL TEST Report Prepared at April 07,2021 1:32 PM

DESCRIPTION

Project Name: Centro Judicial P5Date Created: March 24,2021 11:54 AMPotential Unit: mV/CSELength Unit: ftTemperature Unit: °FTemperature Correction: OnNumber of Nodes (X): 6Node Spacing (X): 4Number of Nodes (Y): 20Node Spacing (Y): 4

SUMMARY

Measurement Range: Area(%)< -350 mV 0.0-350 mV to -200 mV 0.0> -200 mV 100.0

CORROSION POTENTIAL CONTOUR MAP

signature Report Generated by Giatec XCell™

Tabulated file in CSV format is enclosed

HALF-CELL POTENTIAL TEST Report Prepared at April 07,2021 1:34 PM

DESCRIPTION

Project Name: Centro Judicial P6Date Created: March 24,2021 12:16 PMPotential Unit: mV/CSELength Unit: ftTemperature Unit: °FTemperature Correction: OnNumber of Nodes (X): 3Node Spacing (X): 4Number of Nodes (Y): 20Node Spacing (Y): 4

SUMMARY

Measurement Range: Area(%)< -350 mV 0.0-350 mV to -200 mV 0.0> -200 mV 100.0

CORROSION POTENTIAL CONTOUR MAP

signature Report Generated by Giatec XCell™

Tabulated file in CSV format is enclosed

HALF-CELL POTENTIAL TEST Report Prepared at April 07,2021 1:34 PM

DESCRIPTION

Project Name: Centro Judicial P7Date Created: March 24,2021 12:30 PMPotential Unit: mV/CSELength Unit: ftTemperature Unit: °FTemperature Correction: OnNumber of Nodes (X): 3Node Spacing (X): 4Number of Nodes (Y): 20Node Spacing (Y): 4

SUMMARY

Measurement Range: Area(%)< -350 mV 0.0-350 mV to -200 mV 3.3> -200 mV 96.7

CORROSION POTENTIAL CONTOUR MAP

signature Report Generated by Giatec XCell™

Tabulated file in CSV format is enclosed

HALF-CELL POTENTIAL TEST Report Prepared at April 07,2021 1:35 PM

DESCRIPTION

Project Name: Centro Judicial P8Date Created: March 24,2021 12:40 PMPotential Unit: mV/CSELength Unit: ftTemperature Unit: °FTemperature Correction: OnNumber of Nodes (X): 6Node Spacing (X): 4Number of Nodes (Y): 20Node Spacing (Y): 4

SUMMARY

Measurement Range: Area(%)< -350 mV 0.0-350 mV to -200 mV 0.8> -200 mV 99.2

CORROSION POTENTIAL CONTOUR MAP

signature Report Generated by Giatec XCell™

Tabulated file in CSV format is enclosed

HALF-CELL POTENTIAL TEST Report Prepared at April 07,2021 1:36 PM

DESCRIPTION

Project Name: Centro Judicial P9Date Created: March 24,2021 1:26 PMPotential Unit: mV/CSELength Unit: ftTemperature Unit: °FTemperature Correction: OnNumber of Nodes (X): 3Node Spacing (X): 4Number of Nodes (Y): 20Node Spacing (Y): 4

SUMMARY

Measurement Range: Area(%)< -350 mV 0.0-350 mV to -200 mV 1.7> -200 mV 98.3

CORROSION POTENTIAL CONTOUR MAP

signature Report Generated by Giatec XCell™

Tabulated file in CSV format is enclosed

HALF-CELL POTENTIAL TEST Report Prepared at April 07,2021 1:46 PM

DESCRIPTION

SUMMARY

Measurement Range: Area(%)< -350 mV 0.0-350 mV to -200 mV 5.7> -200 mV 94.3

CORROSION POTENTIAL CONTOUR MAP

signature Report Generated by Giatec XCell™

Tabulated file in CSV format is enclosed

Project Name: Centro Judicial Piso 6 (B-C,1-1') P10Date Created: March 25,2021 11:43 AMPotential Unit: mV/CSELength Unit: ftTemperature Unit: °FTemperature Correction: OnNumber of Nodes (X): 10Node Spacing (X): 3Number of Nodes (Y): 7Node Spacing (Y): 3

HALF-CELL POTENTIAL TEST Report Prepared at April 07,2021 1:41 PM

DESCRIPTION

SUMMARY

Measurement Range: Area(%)< -350 mV 0.0-350 mV to -200 mV 1.5> -200 mV 98.5

CORROSION POTENTIAL CONTOUR MAP

signature Report Generated by Giatec XCell™

Tabulated file in CSV format is enclosed

Project Name: Centro Judicial Piso 6 (CD1,2') P11Date Created: March 25,2021 11:13 AMPotential Unit: mV/CSELength Unit: ftTemperature Unit: °FTemperature Correction: OnNumber of Nodes (X): 5Node Spacing (X): 3Number of Nodes (Y): 13Node Spacing (Y): 3

HALF-CELL POTENTIAL TEST Report Prepared at April 07,2021 1:50 PM

DESCRIPTION

SUMMARY

Measurement Range: Area(%)< -350 mV 1.8-350 mV to -200 mV 0.0> -200 mV 98.2

CORROSION POTENTIAL CONTOUR MAP

signature Report Generated by Giatec XCell™

Tabulated file in CSV format is enclosed

Project Name: Judicial Piso 6 (A'-A, 0-1') P12 Date Created: March 25,2021 1:15 PMPotential Unit: mV/CSELength Unit: inTemperature Unit: °FTemperature Correction: OnNumber of Nodes (X): 5Node Spacing (X): 36Number of Nodes (Y): 11Node Spacing (Y): 32

CENTRO JUDICIAL DE AGUADILLA Laboratory Report LR-2021-30 April 22, 2021 Page 45 of 55

4. APPENDIX C – DRAWINGS SKETCHES AND TEST LOCATIONS

1

F

2 3 4 5 6 7 10 9 10

E

D

C

B

A

1

AB-1

02

1

AB-102

2

AB-102

2

AB-102

EXISTING PARKING SLAB

EXISTING MAIN BUILDING 6TH LEVEL ROOF PLAN

PARTIAL ELEVATION

PARTIAL ELEVATION

PARTIAL ELEVATION

4 3 2' 2 1 0

A''

5 0'

A'

A

B

C

D

1'

EXISTING MAIN BUILDING 6TH LEVEL ROOF PLAN

1

F

2 3 4 5 6 7 10 9 10

E

D

C

B

A

EXISTING PARKING SLAB

4 3 2' 2 1 0

A''

5 0'

A'

A

B

C

D

1'

EXISTING MAIN BUILDING 6TH LEVEL ROOF PLAN

1

F

2 3 4 5 6 7 10 9 10

E

D

C

B

A

EXISTING PARKING SLAB

4 3 2' 2 1 0

A''

5 0'

A'

A

B

C

D

1'

EXISTING MAIN BUILDING 6TH LEVEL ROOF PLAN

4 3 2' 2 1 0

A''

5 0'

A'

A

B

C

D

1'

EXISTING MAIN BUILDING 6TH LEVEL ROOF PLAN

1

F

2 3 4 5 6 7 10 9 10

E

D

C

B

A

EXISTING PARKING SLAB

4 3 2' 2 1 0

A''

5 0'

A'

A

B

C

D

1'

EXISTING MAIN BUILDING 6TH LEVEL ROOF PLAN