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This Webinar is sponsored by ACI. The ideas expressed, however, are those of the speakers and do not necessarily reflect the views of ACI or its committees. The audience is expected to exercise judgment as to
the appropriate application of the information.
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ACI 314R-16 "Guide to Simplified Design for Reinforced Concrete Buildings”
WEBINAR 7
For continuing education credit, attendance for the entire duration of the webinar
will earn you a certificate of completion for 1 PDH (0.1 CEU). Your certificate will
be available in ACI University under the Certificates tab within two days.
For those who cannot join us live; the on‐demand recording and quiz will be
made available about a week after the LIVE presentation. Successful completion
of the quiz will earn the certificate.
Certificates will be available in ACI University under the Certificates tab.
Questions related to specific materials, methods, and services will be addressed
at the conclusion of this presentation.
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American Concrete Institute is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this online course will be reported to AIA/CES for AIA members.
The online course based on this webinar is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product.
The American Institute of Architects has approved this course for
1 AIA/CES LU Learning Unit.
The American Institute of Architects has approved this course for 1 AIA/CES LU learning unit.ACI is an AIA/CES registered provider.
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Course Description:This guide is intended for the planning, design, and construction of reinforced concrete structures in new low‐rise buildings of restricted occupancy, number of stories, and area. The Guide is based ACI 318‐14 and ACI IPS‐1, “Essential Requirements for Reinforced Concrete Buildings.” The initial drafting of ACI IPS‐1 (2002) was motivated by frequent worldwide discussions that reinforced concrete codes might be unnecessarily sophisticated for some applications, such as small low‐rise buildings. Although the information presented was developed to produce, when properly used, a reinforced concrete structure with an appropriate margin of safety. For the structure designed by the guide to attain the intended margin of safety, the guide should be used as a whole, and alternative procedures should be used only when explicitly permitted in the guide.
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ACI 314R-16 "Guide to Simplified Design for Reinforced Concrete Buildings”
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ACI 314R-16 "Guide to Simplified Design for Reinforced Concrete Buildings”
Learning Objectives
Describe common reinforcement detailing requirements, such as minimum cover requirements for concrete exposed to earth or weather, bend diameter requirements for deformed bars, and splice length requirements for tension bars and compression bars.
Explain the properties of different types of floor systems: flat slab floor system, slab‐on‐girder floor system, joist floor system, two‐way joist system. Explain advantages and disadvantages.
Explain dimensional requirements and reinforcement details for columns including how the design should be performed and how the requirements for columns in seismic zones should be met.
Explain general wall dimensioning and layout for simple buildings, including how the minimum amount of reinforced concrete structural walls for factored lateral‐force resistance should be computed.
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Luis E. Garcia, Past President
Born in 1948 in Bogotá, Colombia, Civil Engineer from the Universidad de los Andes, Bogotá, Colombia (February 1971), and Master of Science in Civil Engineering from the University of Illinois at Urbana‐Champaign (June 1972).
Mr. Garcia has been involved in consulting in structural engineering since the early seventies. In 1980 he founded Proyectos y Diseños Ltda. (P&D Ltda.), a structural engineering consulting firm in Bogotá, Colombia. He retired from P&D Ltda. in April 2015. At P&D Ltda. he was in charge of the structural design on numerous buildings, industrial structures and bridges in Colombia and other Latin American countries. P&D Ltda. has a design record that includes more than twenty million square meters (2 hundred million square feet) of design area.
He has been engaged in teaching and research at the Universidad de los Andes, Bogotá, Colombia, since 1973, and was Chairman of the Civil Engineering Department 1982‐1983. From 2001 to 2003 he was Visiting Professor of Civil Engineering at Purdue University, West Lafayette, Indiana, USA.
He was President of the American Concrete Institute – ACI for 2008‐2009. Has been a member of Committee ACI 318, “Building Code Requirements for Reinforced Concrete” since 1985, He is a Fellow of ACI and was elected Honorary Member of the American Concrete Institute in March 2017. He is a Fellow and Life Member of the American Society of Civil Engineers – ASCE, member of the Earthquake Engineering Research Institute – EERI, and a Fellow of the International Association of Bridge and Structural Engineers – IABSE. He is also an Honorary Member of the Colombian Society of Engineers.
He has received honors and awards from the American Concrete Institute – ACI, the American Society of Civil Engineers – ASCE, the Universidad de los Andes, the Colombian Association for Earthquake Engineering – AIS, the Colombian Association for Structural Engineering — ACIES, the International Association of Bridge and Structural Engineers –IABSE, the Colombian Society of Engineers, the Colombian Government, the Colombian Association of Ready‐Mixed Concrete Producers, and Cemex Colombia.
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ACI 314R-16 "Guide to Simplified Design for Reinforced Concrete Buildings”
Luis E. Garcia
Independent consultant
August 4, 2020
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ACI 314R-16 "Guide to Simplified Design for Reinforced Concrete Buildings”ACI 314R-16 "Guide to Simplified Design for Reinforced Concrete Buildings”The initial drafting of ACI IPS‐1 (2002) was motivated
by frequent worldwide discussions that reinforced
concrete codes might be unnecessarily sophisticated
for some applications, such as small low‐rise
buildings. Current knowledge on reinforced concrete
behavior obtained through experimentation and
experience, and its status and dissemination as a
structural material used worldwide, made developing
a simplified design and construction guide feasible.
This guide used ACI IPS‐1 (2002) as a basis, with
information derived from the following ACI 318‐14,
ASCE 7‐10, and IBC 2015.
Placeholder PhotoPhoto for Position Only
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Purpose
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Small low‐rise structures
Simplified strength models and minimum dimensional requirements.
Material and construction requirements aimed at the minimum strength grades.
Self‐contained ‐‐ loads, analysis, design, geotechnical and construction ‐‐ all in one!
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Purpose
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Earthquake resistance through walls.
Automatic Code compliance.
Lots of figures.
Order follows the design process.
The document and a hand calculator is all required!
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Outline
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• Chapter 1 – General
• Chapter 2 – Notation and Definitions
• Chapter 3 – Structural system layout
• Chapter 4 – Loads
• Chapter 5 – General reinforced concrete information
• Chapter 6 – Floor system
• Chapter 7 ‐ Solid slabs supported on girders, beams, joists, or reinforced concrete walls
• Chapter 8 – Girders, beams and joists
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Outline
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• Chapter 9 – Slab‐column systems
• Chapter 10 ‐ Columns
• Chapter 11 – Seismic resistance
• Chapter 12 – Reinforced concrete walls
• Chapter 13 – Other structural members
• Chapter 14 – Foundations
• Chapter 15 – Drawings and specifications
• Chapter 16 – Construction
• Chapter 17 ‐ References
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Permitted uses and occupanciesA Assembly Churches, theatres. stadiums, coliseums, ... NO
Assembly rooms for less then 100 people YESB Business Offices, professional , restaurants (occup.< 50 p.) YESE Educational YESF Factory Light industries YES
Heavy industries NOI Institutional Residential board and care facilities YES
Hospitals NOPrisons, jails, reformatories, detention centers YESDay care facilities YES
M Mercantile Display and sale of merchandise YESR Residential Hotels NO
Houses and apartment buildings YESS Storage Storage of light materials YES
Storage of heavy or hazardous materials NOU Utilities and Vehicles up to 4000 lb carrying capacity YES
Miscellaneous Trucks with more than 4000 lb carrying capacity NOWater supply, power generation NO
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Floor Structural Layout
A
B
C
D
1 2 3 4
ab
bc
cd
12 23 34
wall
Slab perforations
column
span
Load path
Column line
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4. Loads
Follows ASCE 7‐10
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4.1 General4.2 Load factors and load combinations4.3 Mass and weight4.4 Weight of materials4.5 Dead loads4.6 Live loads4.7 Roof live loads4.8 Rain load4.9 Snow load4.10 Wind loads4.11 Seismic loads4.12 Soil weight and lateral pressure4.13 Lateral loads4.14 Lateral-force-resisting system4.15.Minimum amount of reinforced concrete structural walls
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Earthquake forces
T
Sa
Sa = 2/3 Ss Fa
as
S WV
R a
s
S WV
R
flat response spectra base shear
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Earthquake forces
triangular force distribution
Response modification
factor
R = 5
Fi
Vs
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Maximum Aggregate Size
a
< a/5
< h/3
h
slab< 3s/4
s s
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Minimum and maximum reinforcing bar diameters
Table 5.3—Minimum and maximum reinforcing bar diameters used in structures Reinforcement type (reference section) Minimum bar diameter
db Maximum bar
diameter db (a) Deformed reinforcing bars (5.2.5.1) 3/8 in. (10 mm) 1 in. (25 mm)
(b) Wire for welded wire reinforcement (5.2.5.2) 0.16 in. (4 mm) 3/8 in. (10 mm)
(c) For stirrups and ties (5.2.5.1) 3/8 in. (10 mm) 5/8 in. (16 mm)
(d) Plain reinforcing bars (5.2.5.3) 3/8 in. (10 mm) 5/8 in. (16 mm)
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Minimum concrete cover to reinforcement
(a) Members cast against and permanently exposed to earth
Minimum concrete cover 3 in. (75 mm)
(b) Members exposed to weather or earth
Minimum concrete cover 2 in. (50 mm)
(c) Girders, beams, or columns, when not exposed to weather or in
contact with ground
Minimum concrete cover 1-1/2 in. (40 mm)
(d) Solid slabs, reinforced concrete walls, or joists, when not exposed to weather or in contact
with ground
Minimum concrete cover 3/4 in. (20 mm)
(e) Solid slabs on grade.
Minimum concrete cover 1-1/2 in. (40 mm)
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Development length, lap splices and reinforcement anchorage
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Development length, lap splices and reinforcement anchorage
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The floor system used by building designer should be one of the systems covered in 6.1
The selection of an appropriate floor system should be made after studying several alternatives
For each of the floor systems covered a description of the system is provided and its restrictions are discussed
The variants of the system are covered
Advantages and disadvantages of each system are discussed
The type of formwork and its complexity are discussed
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Floor systems
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Consists of a grid of girders in both plan directions with a solid slab spanning between girders.
Girders are located on the column lines or axis, spanning the distance between columns.
The solid slab is shallower than the girders and supported by them
One of the main variations is the use of intermediate beams supported on the girders.
Has a relatively low self weight.
The system can accommodate spans of any size, can easily adapt to any plan shape and large perforations, ducts and shafts can be located without major problems.
The formwork can be elaborate. A suspended ceiling may be needed for apartment and office occupancies.
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Slab-on-girder system
slab girder intermediate
one-direction beam
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Parallel ribs or joists supported by girders.
The girders are located on the column lines, and span between columns.
Clear separation between joists, should not exceed 30 in. (750 mm)
When joists have the same depth as the girders, a flat formwork decking supported on shores. Joists shallower than the girders results in more complex formwork.
To create voids, permanent and removable pans or domes of different shape and material are used.
The joist system demands more workmanship than other systems.
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Joist floor system
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For spans approximately equal in both directions, it may be advantageous to use two‐way joists.
Joists should be supported on girders.
Large perforations, ducts, or shafts interrupt several joists thus making design and construction more intricate.
The two‐way joist system demands more workmanship than other systems.
If the joist depth is different than the girder depth, the advantage of a flat formwork decking is lost.
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Two-way joist systems
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In the slab‐column system, the slab is supported directly by the columns, without beams or girders.
A problem associated with this type of system, known since early development of reinforced concrete, is the punching shear failure
Slab‐column systems generally provide a shallower depth. In general, these systems do not need a false ceiling.
Reinforcement placement is easier because it does not require stirrups, thus allowing more efficient construction.
The main disadvantage of these systems is vulnerability to punching shear failure.
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Slab-column systems
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A slab of uniform thickness supported by columns is called a flat plate.
To increase resistance to punching shear the slab can be thickened around the columns. This system is called a flat‐slab system.
In flat‐slab systems using drop panels and column capitals help increase punching‐shear resistance but complicate design and construction.
Perforations, ducts, and shafts should not be located near columns because these openings reduce slab punching shear strength.
The seismic performance of slab‐column systems, when not laterally stiffened by reinforced concrete walls have, at times, not performed as well as other structural systems during seismic events.
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Slab-column systems (Flat-plate and flat-slab systems)
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The thicker, rectangular slab around the column is called a drop panel. When a drop panel is used, the punching shear strength at the column and at the edge of the drop panel needs to be checked.
Another option is to increase the contact area between the column and the slab by forming a column capital.
In some instances, both a capital and a drop panel are combined, two potential zones of punching shear failure exist and both should be checked in design.
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Slab-column systems (column capitals and drop panels)
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For longer spans, voids are formed in the bottom of a flat‐plate, away from the columns. This system is called a waffle‐slab.
For waffle slabs, all members are joists and the voids surrounding the column are filled, thus forming a column capital.
Domes or pans for waffle‐slabs can be permanent, made of concrete block, or removable when made of wood, fiberglass, or plastic.
The seismic performance of slab‐column systems, when not laterally stiffened by reinforced concrete walls have, at times, not performed as well as other structural systems during seismic events.
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Slab-column systems (Waffle slabs)
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Columns should be designed using Chapter 10 which applies to members reinforced with longitudinal bars and lateral ties, and members reinforced with longitudinal bars and a continuous spiral reinforcement. Rectangular and circular sections are permitted.
Columns should meet the requirements for distance between lateral supports and given in the following slide.
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Column design
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Columns
Dimensional requirements
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Interaction diagram for Mn Pn
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Column design for seismic zones
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A minimum amount of reinforced concrete structural walls should be provided for factored lateral‐force resistance.
Structural walls should have rectangular cross sections. Other cross sections are beyond the scope of this guide, except core walls as prescribed in 12.8.
In both principal directions in plan, there should be at least two parallel walls in different planes, and the planes should be as far apart as practical. The walls should be placed as close to the periphery of the building as practical.
Walls should be located as symmetrically as possible with respect to the centers of mass and stiffness of each floor
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Minimum amount of reinforced concrete structural walls
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A minimum wall area for shear strength is required at any floor by at least two walls and they should be able to resist the shear.
The minimum wall dimensions depend on the number of stories above the base.
Structural walls should have rectangular cross sections.
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Minimum amount of reinforced concrete structural walls
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Structural walls should have rectangular cross sections.
Structural walls should be vertically continuous from foundation to roof.
Structural walls should be aligned vertically.
Structural walls should not have openings for windows or doors.
In both principal directions in plan, there should be at least two parallel walls in different planes, and the planes should be as far apart as practical. The walls should be placed as close to the periphery of the building as practical.
Walls should be located as symmetrically as possible with respect to the centers of mass and stiffness of each floor.
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4.15 Minimum amount of reinforced concrete structural walls
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Minimum wall area for shear strength—At any floor i, for the two principal directions, x and y, the minimum cross‐sectional area (Ag = wbw) for all reinforced concrete walls acting in the principal direction under consideration should be determined from the following equation:
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4.15 Minimum amount of reinforced concrete structural walls
iuw w
c
V( b )
2 f
iuw w
c
6V( b ) (SI)
f
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Minimum wall dimensions for lateral stiffness—Slenderness ratio hw/w for any individual wall should comply with following equation, and the wall thickness bw should comply with Chapter 12. (ns = no. of stories above the base)
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4.15 Minimum amount of reinforced concrete structural walls
w s
w
h 3 n
2
(added graphic from ACI 314‐16)
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Thank you!
For the most update to date information please
visit the American Concrete Institute at:
concrete.org
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ACI 314R-16 "Guide to Simplified Design for Reinforced Concrete Buildings”
Questions?
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www.ACIUniversity.com
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ACI 314R-16 "Guide to Simplified Design for Reinforced Concrete Buildings”
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