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NZS 3101-2 (2006) (English): Concrete structures standard - Commentary [By Authority of Development Sponsored By the Earthquake Commission (EQC) and Department of Building and Housing (DBH)] We will sell to no man, we will not deny or defer to any man either justice or right. Magna Carta— T ūtohinga Nui Kore rawa e hoko ki te tangata, e kore e whakakhoretia, ā e tautuku rnei te tangata ki te ture, tika ranei. ā NZS 3101:Part 2:2006 H Incorporating Amendment NO.1 & 2 Concrete Structures Standard - STANDARDS NEW ZEALAND Commentary PAEREWA AOTEA ROA New Zealand Standard CONCRETE STRUCTllRES STANDARD Part 2- Commentary on the Design of Concrete Structures ISBN 1-86975-043-8 COMMITTEE REPRESENTATION This Standard was prepared by the Concrete Design Committee P 3101 for the Standards Council established under the Standards Act 1988. The committee consisted of representatives of the following: Name Nominating Organisation Dene Cook Cement and Concrete Association of New Zealand (Chair) Peter Attwood New Zealand Contractor's Federation Derek Chisholm BRANZ Richard Fenwick Co-opted Don Kirkcaldie IPENZ Graeme Lawrance Department of Building and Housing Len McSaveney New Zealand Concrete Society Inc John Mander University of Canterbury Les Megget The University of Auckland Bob Park Co-opted Ashley Smith NZ Structural Engineering Society Keith Towl Business New Zealand ACKNOWLEDGEMENT Standards New Zealand gratefully acknowledges: (a) The significant contribution towards the development of this Standard made by (the late) Professor Bob Park; (b) The assistance provided by Stefano Pampanin for work on Appendix B; and (c) The American Concrete Institute for permission to use extracts from ACI 318-02, Building Code Requirements for Reinforced Concrete. Appendix CF contains specific information related to ACI 318 provisions. COPYRIGHT The copyright of this document is the property of the Standards Council. No part of it may be reproduced by photocopying or by any other means without the prior written approval of the Chief Executive of Standards New Zealand unless the circumstances are covered by Part III of the Copyright Act 1994. Standards New Zealand will vigorously defend the copyright in this Standard. Every person who breaches Standards New Zealand's copyright may be liable to a fine not exceeding $50,000 or to imprisonment for a term of not to exceed three months. If there has been a flagrant breach of copyright, Standards New Zealand may also seek additional damages from the infringing party, in addition to obtaining injunctive relief and an account of profits. Published by Standards New Zealand, the trading arm of the Standards Council, Private Bag 2439, Wellington 6140. Telephone (04) 4985990, Fax (04) 4985994. Website www.standards.co.nz AMENDMENTS No. Date of issue Description Entered by, and date 1 July 2006 Corrects minor errors SNZ July 2006 2 August 2008 Amends clauses, equations, figures, notations, SNZ August 2008 referenced documents and tables NZS 3101 :Part 2:2006 © 2006 STANDARDS COUNCil Approved by the Standards Council on 17 March 2006 to be a !\lew Zealand Standard pursuant to the provisions of section 10 of the Standards Act 1988. First published: 17 March 2006 The following SNZ references relate to this Standard: Project No. P 3101 Draft for comment No. DZ 3101 Typeset and printed by: The Colour Guy NZS 3101:Part 2:2006 Contents Committee Representation ........................................................................................................................ IFC Acknowledgement ..................................................................................................................................... IFC Copyright ................................................................................................................................................... IFC Referenced Documents ........................................................................................................................... C-ix C1 GENERAL .................................................................................................................................... C1-1 C1.1 Scope ........................................................................................................................... C1-1 C1.3 Design .......................................................................................................................... C1-2 C 1.4 Construction ................................................................................................................. C 1-2 C1.S Definitions ..................................................................................................................... C1-3 C2 DESIGN PROCEDURES, LOADS AND ACTIONS ..................................................................... C2-1 C2.1 Notation ........................................................................................................................ C2-1 C2.2 Design requirements .................................................................................................... C2-1 C2.3 Design for strength and stability at the ultimate limit state ........................................... C2-1 C2.4 Design for serviceability ............................................................................................... C2-3 C2.S Other design requirements ........................................................................................... C2-6 C2.6 Additional design requirements for earthquake effects ................................................ C2-7 C3 DESIGN FOR DURABILITy ......................................................................................................... C3-1 C3.2 Scope ........................................................................................................................... C3-1 C3.3 Design life ..................................................................................................................... C3-2 C3.4 Exposure classification ................................................................................................. C3-2 C3.S Requirements for aggressive soil and groundwater exposure classification XA ......... C3-6 C3.6 Minimum concrete curing requirements ....................................................................... C3-6 C3.7 Additional requirements for concrete for exposure classification C ............................. C3-7 C3.B Requirements for concrete for exposure classification U ............................................. C3-8 C3.9 Finishing, strength and curing requirements for abrasion ............................................ C3-8 C3.10 Requirements for freezing and thawing ..................................................................... C3-1 0 C3.11 Requirements for concrete cover to reinforcing steel and tendons ............................ C3-1 0 C3.12 Chloride based life prediction models and durability enhancement measures .......... C3-11 C3.13 Protection of cast-in fixings and fastenings ................................................................ C3-13 C3.14 Restrictions on chemical content in concrete ............................................................. C3-14 C3.1S Alkali silica reaction .................................................................................................... C3-14 C4 DESIGN FOR FIRE RESiSTANCE .............................................................................................. C4-1 C4.2 Scope ........................................................................................................................... C4-1 C4.3 Design performance criteria ......................................................................................... C4-2 C4.4 Fire resistance ratings for beams ................................................................................. C4-3 C4.S Fire resistance ratings for slabs ................................................................................... C4-3 C4.6 Fire resistance ratings for columns .............................................................................. C4-3 C4.7 Fire resistance ratings for walls .................................................................................... C4-3 C4.B External walls that could collapse outwards in fire ....................................................... C4-4 C4.10 Fire resistance rating by calculation ............................................................................. C4-6 CS DESIGN PROPERTIES OF MATERIALS .................................................................................... CS-1 CS.1 Notation ........................................................................................................................ CS-1 CS.2 Properties of concrete .................................................................................................. C5-1 CS.3 Properties of reinforcement .......................................................................................... CS-3 CS.4 Properties of tendons ................................................................................................... C5-S CS.S Properties of steel fibre reinforced concrete ................................................................ CS-S APPENDIX A TO CS DESIGN PROPERTIES OF MATERIALS ......................................................... CS-7 CSA TEST AND DESIGN METHODS FOR STEEL FIBRE REINFORCED CONCRETE SUBJECTED TO MONOTONIC LOADING ............................................ CS-7 CS.A 1 Notation ........................................................................................................................ CS-7 CS.A2 Introduction ................................................................................................................... CS-B C - i NZS 3101:Part 2:2006 ----------------------------------------------------------- C5.A3 Material properties ........................................................................................................ C5-9 C5.A4 Design at ultimate limit states ..................................................................................... C5-11 C5.A5 Design at serviceability limit states ............................................................................. C5-16 C5.A6 Detailing provisions .................................................................................................... C5-17 CS.A7 Derivation of stresses in a- {; diagram test .............................................................. CS-1S C6 METHODS OF STRUCTURAL ANALYSIS ................................................................................. C6-1 C6.1 Notation ........................................................................................................................ C6-1 C6.2 General ......................................................................................................................... C6-1 C6.3 Linear elastic analysis .................................................................................................. C6-2 C6.4 Non-linear structural analysis ....................................................................................... C6-6 C6.5 Plastic methods of analysis .......................................................................................... C6-7 C6.6 Analysis using strut-and-tie models ............................................................................. C6-7 C6.7 Simplified methods of flexural analysis ........................................................................ C6-7 C6.S Calculation of deflection ............................................................................................. C6-14 C6.9.1 Linear elastic analysis ................................................................................................ C6-16 C7 FLEXURE, SHEAR AND TORSIONAL STRENGTH OF MEMBERS WITH OR WITHOUT AXIAL LOAD ............................................................................................................... C7-1 C7.1 Notation ........................................................................................................................ C7-1 C7.2 Scope ........................................................................................................................... C7-1 C7.3 General principles ........................................................................................................ C7-1 C7.4 Flexural strength of members with shear and with or without axial load ...................... C7-2 C7.5 Shear strength of members .......................................................................................... C7-4 C7.6 Torsional strength of members with flexure and shear with and without axial loads ............................................................................................................................. C7-6 C7.7 Shear-friction .............................................................................................................. C7-12 CS STRESS DEVELOPMENT, DETAILING AND SPLICING OF REINFORCEMENT AND TENDONS .................................................................................................................................... C8-1 CS.1 Notation ........................................................................................................................ CS-1 CS.2 Scope ........................................................................................................................... CS-1 CS.3 Spacing of reinforcement ............................................................................................. C8-1 CS.4 Bending of reinforcement ............................................................................................. CS-2 CS.S Welding of reinforcement ............................................................................................. C8-4 CS.6 Development of reinforcement ..................................................................................... CS-4 CS.7 Splices in reinforcement ............................................................................................. CS-1S CS.S Shrinkage and temperature reinforcement... .............................................................. CS-1S CS.9 Additional design requirements for structures designed for earthquake effects ........ CS-1S C9 DESIGN OF REINFORCED CONCRETE BEAMS AND ONE-WAY SLABS FOR STRENGTH, SERVICEABILITY AND DUCTILITY ...................................................................... C9-1 C9.1 Notation ........................................................................................................................ C9-1 C9.3 General principles and design requirements for beams and one-way slabs ............... C9-1 C9.4 Additional design requirements for structures designed for earthquake effects ........ C9-13 C10 DESIGN OF REINFORCED CONCRETE COLUMNS AND PIERS FOR STRENGTH AND DUCTILITY ........................................................................................................................ C10-1 C10.1 Notation ...................................................................................................................... C10-1 C10.3 General principles and design requirements for columns and piers .......................... C10-1 C10.4 Additional design requirements for structures designed for earthquake effects ...... C 10-11 C11 DESIGN OF STRUCTURAL WALLS FOR STRENGTH, SERVICEABILITY AND DUCTILITY ................................................................................................................................. C11-1 C11.1 Notation ...................................................................................................................... C11-1 C11.2 Scope ......................................................................................................................... C11-1 C11.3 General principles and design requirements for structural walls ............................... C11-1 C11.4 Additional design requirements for members designed for ductility in earthquakes ................................................................................................................ C 11-3 C - ii