A233-04 Design of concrete structures
A23.3-04 Design of concrete structures
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Legal Notice for Standards Canadian Standards Association (CSA) standards are developed through a consensus standards development process approved by the Standards Council of Canada. This process brings together volunteers representing varied viewpoints and interests to achieve consensus and develop a standard. Although CSA administers the process and establishes rules to promote fairness in achieving consensus, it does not independently test, evaluate, or verify the content of standards. Disclaimer and exclusion of liability This document is provided without any representations, warranties, or conditions of any kind, express or implied, including, without limitation, implied warranties or conditions concerning this document’s fitness for a particular purpose or use, its merchantability, or its non-infringement of any third party’s intellectual property rights. CSA does not warrant the accuracy, completeness, or currency of any of the information published in this document. CSA makes no representations or warranties regarding this document’s compliance with any applicable statute, rule, or regulation. IN NO EVENT SHALL CSA, ITS VOLUNTEERS, MEMBERS, SUBSIDIARIES, OR AFFILIATED COMPANIES, OR THEIR EMPLOYEES, DIRECTORS, OR OFFICERS, BE LIABLE FOR ANY DIRECT, INDIRECT, OR INCIDENTAL DAMAGES, INJURY, LOSS, COSTS, OR EXPENSES, HOWSOEVER CAUSED, INCLUDING BUT NOT LIMITED TO SPECIAL OR CONSEQUENTIAL DAMAGES, LOST REVENUE, BUSINESS INTERRUPTION, LOST OR DAMAGED DATA, OR ANY OTHER COMMERCIAL OR ECONOMIC LOSS, WHETHER BASED IN CONTRACT, TORT (INCLUDING NEGLIGENCE), OR ANY OTHER THEORY OF LIABILITY, ARISING OUT OF OR RESULTING FROM ACCESS TO OR POSSESSION OR USE OF THIS DOCUMENT, EVEN IF CSA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, INJURY, LOSS, COSTS, OR EXPENSES. In publishing and making this document available, CSA is not undertaking to render professional or other services for or on behalf of any person or entity or to perform any duty owed by any person or entity to another person or entity. The information in this document is directed to those who have the appropriate degree of experience to use and apply its contents, and CSA accepts no responsibility whatsoever arising in any way from any and all use of or reliance on the information contained in this document. CSA is a private not-for-profit company that publishes voluntary standards and related documents. CSA has no power, nor does it undertake, to enforce compliance with the contents of the standards or other documents it publishes. Intellectual property rights and ownership As between CSA and the users of this document (whether it be in printed or electronic form), CSA is the owner of all works contained herein that are protected by copyright, all trade-marks (except as otherwise noted to the contrary), and all inventions and trade secrets that may be contained in this document, whether or not such inventions and trade secrets are protected by patents and applications for patents. The unauthorized use, modification, copying, or disclosure of this document may violate laws that protect CSA’s intellectual property and may give rise to a right in CSA to seek legal redress for such use, modification, copying, or disclosure. CSA reserves all intellectual property rights in this document. Authorized use of this document This document is being provided by CSA for informational and non-commercial use only. The user of this document is authorized to do only the following: If this document is in electronic form: . load this document onto a computer for the sole purpose of reviewing it; . search and browse this document; and . print this document. Limited copies of this document in print or paper form may be distributed only to persons who are authorized by CSA to have such copies, and only if this Legal Notice appears on each such copy. In addition, users may not and may not permit others to . alter this document in any way or remove this Legal Notice from the attached standard; . sell this document without authorization from CSA; or . make an electronic copy of this document. If you do not agree with any of the terms and conditions contained in this Legal Notice, you may not load or use this document or make any copies of the contents hereof, and if you do make such copies, you are required to destroy them immediately. Use of this document constitutes your acceptance of the terms and conditions of this Legal Notice
CSA Standards Update Service A23.3-04 December 2004 Title: Design of concrete structures Pagination: 232 pages(xvii preliminary and 214 text), each dated December 2004 Automatic notifications about any updates to this publication are available To register for e-mail notifications, and/or to download any existing updates in PDF, enter theOnlineStoreatwww.Shopcsa.caandclickonMyAccountonthenavigationbar The list id for this document is 2015962 To receive printed updates, please complete and return the attached card i Name Organization Address y Province/state Count Postal/ Zip Code consent to CSA collecting and using the above information to send me updates relating to this publication VisitCsa'spolicyonprivacyatwww.csagroup.org/legaltofindouthowweprotectyourpersonalinformation A23.3-04
Name Organization Address City Province/State Country Postal/Zip Code E-mail I consent to CSA collecting and using the above information to send me updates relating to this publication. Visit CSA’s policy on privacy at www.csagroup.org/legal to find out how we protect your personal information. A23.3-04 CSA Standards Update Service A23.3-04 December 2004 Title: Design of concrete structures Pagination: 232 pages (xviii preliminary and 214 text), each dated December 2004 Automatic notifications about any updates to this publication are available. • To register for e-mail notifications, and/or to download any existing updates in PDF, enter the Online Store at www.ShopCSA.ca and click on My Account on the navigation bar. The List ID for this document is 2015962. • To receive printed updates, please complete and return the attached card
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CSA Standard A23.3-04 Design of concrete structures CANADIAN STANDARDS ASSOCIATION Registered trade-mark of Canadian Standards Association Published in December 2004 by Canadian Standards Association A not-for-profit private sector organization 5060 Spectrum Way, Suite 100, Mississauga, Ontario, Canada L4W5N6 1-800463-6727·416-7474044 VisitourOnlineStoreatwww.shopcsa.ca
Published in December 2004 by Canadian Standards Association A not-for-profit private sector organization 5060 Spectrum Way, Suite 100, Mississauga, Ontario, Canada L4W 5N6 1-800-463-6727 • 416-747-4044 Visit our Online Store at www.ShopCSA.ca A23.3-04 Design of concrete structures CSA Standard
SBN1-55397-5596 Technical editor: Muktha Tumkur o Canadian Standards Association --2004 All rights reserved. No part of this publication may be reproduced in any form whatsoever without the prior permission of the publisher
ISBN 1-55397-559-6 Technical Editor: Muktha Tumkur © Canadian Standards Association — 2004 All rights reserved. No part of this publication may be reproduced in any form whatsoever without the prior permission of the publisher
Canadian Standards Association Design of concrete structures Contents Technical Committee on Reinforced Concrete Design xiv Preface x General 1 Fire resistance 1 1.3 Alternative design procedure Terminology 1 1.5 Units of measurement 1 2 Reference publications, definitions, symbols, and standard notation and calculations 2 2.1 Reference publications 2 Definitions 3 2.3 Symbols 10 2.4 Standard notation and calculations 20 2.4.1 Standard notation for loads and resistances 20 2.4.2 Standard notation for reinforcing bars 20 2.4.3 Bar diameter for calculations 21 3 Materials Reinforcement 2 3.2 Concrete and other materials 21 4 Concrete quality, mixing, and placement 22 4.1 Mixing and placement 22 5 Drawings and related documents 22 6 Formwork, falsework, embedded pipes, and construction joints 22 General 22 6.2 Embedded pipes and openings 22 6.3 Construction joints 23 7 Details of reinforcement 23 7.1 Hooks bends and headed bars 23 7.1.1 ener 7.1.2 Stirrups and ties 23 Crossties 23 Headed bars and studs 23 7,2 Placing of reinforcement 23 7.2.1 General 23 7.2.2 Draped fabric 23 Tolerances 24 pacing of reinforcement and tendons 24 Bars 24 Bundled bars 24 7.4.3 Pretensioning tendons 24 Post-tensioning tendons 25 Special details for columns and walls 25 December 2004
December 2004 iii Contents © Canadian Standards Association Design of concrete structures Technical Committee on Reinforced Concrete Design xiv Preface xvii 1 Scope 1 1.1 General 1 1.2 Fire resistance 1 1.3 Alternative design procedures 1 1.4 Terminology 1 1.5 Units of measurement 1 2 Reference publications, definitions, symbols, and standard notation and calculations 2 2.1 Reference publications 2 2.2 Definitions 3 2.3 Symbols 10 2.4 Standard notation and calculations 20 2.4.1 Standard notation for loads and resistances 20 2.4.2 Standard notation for reinforcing bars 20 2.4.3 Bar diameter for calculations 21 3 Materials 21 3.1 Reinforcement 21 3.2 Concrete and other materials 21 4 Concrete quality, mixing, and placement 22 4.1 Quality 22 4.2 Mixing and placement 22 5 Drawings and related documents 22 6 Formwork, falsework, embedded pipes, and construction joints 22 6.1 General 22 6.2 Embedded pipes and openings 22 6.3 Construction joints 23 7 Details of reinforcement 23 7.1 Hooks, bends, and headed bars 23 7.1.1 General 23 7.1.2 Stirrups and ties 23 7.1.3 Crossties 23 7.1.4 Headed bars and studs 23 7.2 Placing of reinforcement 23 7.2.1 General 23 7.2.2 Draped fabric 23 7.3 Tolerances 24 7.4 Spacing of reinforcement and tendons 24 7.4.1 Bars 24 7.4.2 Bundled bars 24 7.4.3 Pretensioning tendons 24 7.4.4 Post-tensioning tendons 25 7.5 Special details for columns and walls 25
A23.3-04 rds Association 7.5.1 Offset bars 25 7.5.2 Splices and load transfer in metal cores 25 7.6 Transverse reinforcement 25 7.6.1 General 25 7.6.2 Composite columns 25 7.6.3 Prestressing tendons 25 7.6.4 Spirals for compression members 25 7.6.5 Ties for compression members 26 7.6.6 Beams and girders- Transverse reinforcement 27 7.7 Special details for beam-column connections 27 7.8 Minimum reinforcement in slabs 27 Concrete protection for reinforcement 28 8 Design-Limit states, load combinations, and material properties 28 8.1 Limit states 28 8.1.1 8.1.2 Fire resistance 28 8.1.3 Ultimate limit states 28 8.1.4 Serviceability limit states 28 8.1.5 Structural integrity 29 8.2 8.2.1 General 29 8.2.2 Imposed deformations 29 8.3 Load combinations and load factors 29 8.3.1 General 29 8.3.2 Load combinations for ultimate limit states 29 8.3.3 Load combinations for serviceability limit states 30 8.4 Factored resistance 30 8.4.1 General 30 8.4.2 Factored concrete strength 3( 8.4.3 Factored reinforcement and tendon force 30 8.5 Reinforcement and tendon properties for design 30 8.5.1 Design strength for reinforcement 30 8.5.2 ompression reinforcement 30 8.5.3 Stress-strain 8.5. 4 Modulus of elasticity of reinforcement 31 8.5.5 Coefficient of thermal expansion of reinforcement 31 8.6 ete properties for 8.6.1 Design strength of concrete 37 8.6.2 Modulus of elasticity 31 8.6.3 Concrete stress-strain relationship 32 8.6.4 Modulus of rupture of concrete 32 8.6.5 Modification factors for concrete density 32 8.6.6 Coefficient of thermal expansion of concrete 32 9 Structural analysis and computation of deflections 32 Methods of analysis 32 9.2 Elastic frame analysis 33 9.2.1 Stiffness 33 9.2.2 Span length 33 9. 2.3 Arrangement of loads 33 9.2.4 Redistribution of moments in continuous flexural members 34 December 2004
A23.3-04 © Canadian Standards Association iv December 2004 7.5.1 Offset bars 25 7.5.2 Splices and load transfer in metal cores 25 7.6 Transverse reinforcement 25 7.6.1 General 25 7.6.2 Composite columns 25 7.6.3 Prestressing tendons 25 7.6.4 Spirals for compression members 25 7.6.5 Ties for compression members 26 7.6.6 Beams and girders — Transverse reinforcement 27 7.7 Special details for beam-column connections 27 7.8 Minimum reinforcement in slabs 27 7.9 Concrete protection for reinforcement 28 8 Design — Limit states, load combinations, and material properties 28 8.1 Limit states 28 8.1.1 Durability 28 8.1.2 Fire resistance 28 8.1.3 Ultimate limit states 28 8.1.4 Serviceability limit states 28 8.1.5 Structural integrity 29 8.2 Loading 29 8.2.1 General 29 8.2.2 Imposed deformations 29 8.2.3 Prestress 29 8.3 Load combinations and load factors 29 8.3.1 General 29 8.3.2 Load combinations for ultimate limit states 29 8.3.3 Load combinations for serviceability limit states 30 8.4 Factored resistance 30 8.4.1 General 30 8.4.2 Factored concrete strength 30 8.4.3 Factored reinforcement and tendon force 30 8.5 Reinforcement and tendon properties for design 30 8.5.1 Design strength for reinforcement 30 8.5.2 Compression reinforcement 30 8.5.3 Stress-strain curve for reinforcement 30 8.5.4 Modulus of elasticity of reinforcement 31 8.5.5 Coefficient of thermal expansion of reinforcement 31 8.6 Concrete properties for design 31 8.6.1 Design strength of concrete 31 8.6.2 Modulus of elasticity 31 8.6.3 Concrete stress-strain relationship 32 8.6.4 Modulus of rupture of concrete 32 8.6.5 Modification factors for concrete density 32 8.6.6 Coefficient of thermal expansion of concrete 32 9 Structural analysis and computation of deflections 32 9.1 Methods of analysis 32 9.2 Elastic frame analysis 33 9.2.1 Stiffness 33 9.2.2 Span length 33 9.2.3 Arrangement of loads 33 9.2.4 Redistribution of moments in continuous flexural members 34 9.3 Approximate frame analysis 34
Canadian Standards Association gn of concrete structures 9.3.1 General 34 9.3.2 Floor and roof loads 34 9.3.3 Moment and shear coefficients 34 Analysis by strut-and-tie models 35 9.5 Finite element analysis 35 9.6 Elastic plate analysis 36 Plastic analysis 36 9.8 Control of deflections 36 9.8.1 General 36 9.8.2 One-way construction(non-prestressed) 36 9.8.3 Two-way construction(non-prestressed) 38 9.8.4 Prestressed concrete construction 38 9.8.5 Composite construction 39 10 Flexure and axial loads 40 10.1 General principles 40 10.1.1 General 40 10.1.2 Plane sections assumption 41 10.1.3 Maximum concrete strain 41 10.14 Balanced strain conditions 41 10.1.5 Tensile strength of concrete 41 10.1.6 Concrete stress-strain relationship 41 10. 1.7 Equivalent rectangular concrete stress distribution 41 Flexural members- Distance between lateral supports 41 Flexural members -T-beams 42 Flexural members-Joist construction 42 Flexural members- Reinforcement 42 10.5.1 Minimum reinforcement 42 10.5.2 Limit of c/d for yielding of tension reinforcement 43 10.5.3 Reinforcement in T-beam flanges 43 Beams and one-way slabs-Crack control 43 10.6.1 Crack control parameter 43 10.6.2 Skin reinforcement 44 10.7 Deep flexural members 44 ).8 Design of bearing zones 44 10.9 Columns- Reinforcement limits 44 10.10 Columns - Resistance 45 10.11 Columns- Design dimensions 46 10.11.1 Equivalent circular column 46 10.11.2 Column built monolithically with wall 46 10.11.3 Isolated column with interlocking spirals 46 10.12 Columns- Transmission of loads through floor system 46 10.14 Member properties for computation of slenderness effects 47 10.14.1 Genera47 10.14.2 Radius of gyration 47 10.14.3 Unsupported length of compression members 4 10.14.4 Designation as non-sway 48 10.14.5 Columns in non-sway frames or storeys 48 10.14.6 Columns in sway frames or storeys 48 10.15 Slenderness effects-Non-sway frames 48 10. 15.1 Effective length factor 48 10.15.2 Non-sway frames 48 10.15.3 Member stability effect 49 December 2004
© Canadian Standards Association Design of concrete structures December 2004 v 9.3.1 General 34 9.3.2 Floor and roof loads 34 9.3.3 Moment and shear coefficients 34 9.4 Analysis by strut-and-tie models 35 9.5 Finite element analysis 35 9.6 Elastic plate analysis 36 9.7 Plastic analysis 36 9.8 Control of deflections 36 9.8.1 General 36 9.8.2 One-way construction (non-prestressed) 36 9.8.3 Two-way construction (non-prestressed) 38 9.8.4 Prestressed concrete construction 38 9.8.5 Composite construction 39 10 Flexure and axial loads 40 10.1 General principles 40 10.1.1 General 40 10.1.2 Plane sections assumption 41 10.1.3 Maximum concrete strain 41 10.1.4 Balanced strain conditions 41 10.1.5 Tensile strength of concrete 41 10.1.6 Concrete stress-strain relationship 41 10.1.7 Equivalent rectangular concrete stress distribution 41 10.2 Flexural members — Distance between lateral supports 41 10.3 Flexural members — T-beams 42 10.4 Flexural members — Joist construction 42 10.5 Flexural members — Reinforcement 42 10.5.1 Minimum reinforcement 42 10.5.2 Limit of c /d for yielding of tension reinforcement 43 10.5.3 Reinforcement in T-beam flanges 43 10.6 Beams and one-way slabs — Crack control 43 10.6.1 Crack control parameter 43 10.6.2 Skin reinforcement 44 10.7 Deep flexural members 44 10.8 Design of bearing zones 44 10.9 Columns — Reinforcement limits 44 10.10 Columns — Resistance 45 10.11 Columns — Design dimensions 46 10.11.1 Equivalent circular column 46 10.11.2 Column built monolithically with wall 46 10.11.3 Isolated column with interlocking spirals 46 10.12 Columns — Transmission of loads through floor system 46 10.13 Slenderness effects — General 46 10.14 Member properties for computation of slenderness effects 47 10.14.1 General 47 10.14.2 Radius of gyration 47 10.14.3 Unsupported length of compression members 48 10.14.4 Designation as non-sway 48 10.14.5 Columns in non-sway frames or storeys 48 10.14.6 Columns in sway frames or storeys 48 10.15 Slenderness effects — Non-sway frames 48 10.15.1 Effective length factor 48 10.15.2 Non-sway frames 48 10.15.3 Member stability effect 49
A23.3-04 rds Association 10. 16 Slenderness effects- Sway frames 49 10.16.1 Effective length factor 49 10.16.2 End moments 49 10.16.3 Calculation of m. 50 10.16.4 Slenderness limit 50 10. 16.5 Strength and stability checks 50 10.16.6 Moment magnification for flexural members 50 0.17 Composite columns-General 51 10.18 Composite column with spiral reinforcement 5 10.19 Composite column with tie reinforcement 52 11 Shear and torsion 53 1.1 General 53 11.1.1 53 11.1.2 Regions near discontinuities 53 11.1.3 Interface regions 53 11.1.4 labs and footings 53 11.15 Alternative methods 53 11.2 Design requirements 53 11.2.1 Tension due to restraint 53 11.2.2 Variable depth members 53 11.2.3 Openings 53 11.2.4 Types of shear reinforcement 53 1.2.5 Anchorage of shear reinforcement 54 11.2.6 Types of torsion reinforcement 54 11.2.7 Anchorage of torsion reinforcement 54 11.28 Minimum shear reinforcement 54 11.2.9 Consideration of torsion 55 11.2.10 Effective web width 55 11.2.11 Reduced prestress in transfer length 56 Design for shear and torsion in flexural regions s>ams 56 11.2.12 Hanger reinforcement for beams supporting other bea 11.3.1 Required shear resistance 57 11.3.2 Sections near supports 57 11.3.3 Factored shear resistance 57 11.3.4 Determination of v 57 11.3.5 Determination of Vs 57 11.3.6 Determination of B and 0 58 11.3.7 Proportioning of transverse reinforcement 60 11.3.8 Maximum spacing of transverse reinforcement 60 11.3.9 Proportioning of longitudinal reinforcement 60 11.3.10 Sections subjected to combined shear and torsion 61 Strut-and-tie model 62 11.4.1 Structural idealization 62 11.4.2 Proportioning of strut 62 11.4.3 Proportioning of ties 64 11.4.4 Proportioning of node regions 64 11.4.5 Crack control reinforcement 64 11.5 Interface shear transfer 64 11.5.1 Genera|64 11.5.2 Values of c and u 65 11.5.3 Alternative equation for shear stress resistance 65 11.5.4 Values of o and py 65 11.5.5 Inclined shear friction reinforcement 65 December 2004
A23.3-04 © Canadian Standards Association vi December 2004 10.16 Slenderness effects — Sway frames 49 10.16.1 Effective length factor 49 10.16.2 End moments 49 10.16.3 Calculation of δsMs 50 10.16.4 Slenderness limit 50 10.16.5 Strength and stability checks 50 10.16.6 Moment magnification for flexural members 50 10.17 Composite columns — General 51 10.18 Composite column with spiral reinforcement 51 10.19 Composite column with tie reinforcement 52 11 Shear and torsion 53 11.1 General 53 11.1.1 Flexural regions 53 11.1.2 Regions near discontinuities 53 11.1.3 Interface regions 53 11.1.4 Slabs and footings 53 11.1.5 Alternative methods 53 11.2 Design requirements 53 11.2.1 Tension due to restraint 53 11.2.2 Variable depth members 53 11.2.3 Openings 53 11.2.4 Types of shear reinforcement 53 11.2.5 Anchorage of shear reinforcement 54 11.2.6 Types of torsion reinforcement 54 11.2.7 Anchorage of torsion reinforcement 54 11.2.8 Minimum shear reinforcement 54 11.2.9 Consideration of torsion 55 11.2.10 Effective web width 55 11.2.11 Reduced prestress in transfer length 56 11.2.12 Hanger reinforcement for beams supporting other beams 56 11.3 Design for shear and torsion in flexural regions 57 11.3.1 Required shear resistance 57 11.3.2 Sections near supports 57 11.3.3 Factored shear resistance 57 11.3.4 Determination of Vc 57 11.3.5 Determination of Vs 57 11.3.6 Determination of β and θ 58 11.3.7 Proportioning of transverse reinforcement 60 11.3.8 Maximum spacing of transverse reinforcement 60 11.3.9 Proportioning of longitudinal reinforcement 60 11.3.10 Sections subjected to combined shear and torsion 61 11.4 Strut-and-tie model 62 11.4.1 Structural idealization 62 11.4.2 Proportioning of strut 62 11.4.3 Proportioning of ties 64 11.4.4 Proportioning of node regions 64 11.4.5 Crack control reinforcement 64 11.5 Interface shear transfer 64 11.5.1 General 64 11.5.2 Values of c and µ 65 11.5.3 Alternative equation for shear stress resistance 65 11.5.4 Values of σ and ρ v 65 11.5.5 Inclined shear friction reinforcement 65
