BUILDING CODE REQUIREMENTS FOR STRUCTURAL …

1 BUILDING CODE REQUIREMENTS FOR. STRUCTURAL CONCRETE (ACI 318-99) AND. COMMENTARY (ACI 318R-99). REPORTED BY ACI COMMITTEE 318. ACI Committee 318. Standard BUILDING Code James R. Cagley Basile G. Rabbat Chairman Secretary Craig E. Barnes S. K. Ghosh Gary J. Klein Jack P. Moehle Florian G. Barth Hershell Gill Cary S. Kopczynski Walter P. Moore, Jr.*. Roger J. Becker David P. Gustafson James Lefter Glen M. Ross John E. Breen James R. Harris H. S. Lew Charles G. Salmon Anthony P. Chrest Neil M. Hawkins James G. MacGregor Mete A. Sozen W. Gene Corley C. Raymond Hays John A. Martin, Jr. Dean E. Stephan Robert A. Epifano Richard E. Holguin Leslie D. Martin Richard A. Vognild Catherine W. French Phillip J. Iverson Robert F. Mast Joel S. Weinstein Luis E. Garcia James O. Jirsa Richard C. Meininger James K. Wight Loring A. Wyllie, Jr. *. Deceased Voting Subcommittee Members Kenneth B.

2 Bondy D. Kirk Harman Joe Maffei Randall W. Poston Stephen J. Seguirant Ronald A. Cook Terence C. Holland Steven L. McCabe Julio A. Ramirez Roberto Stark Richard W. Furlong Kenneth C. Hover Gerard J. McGuire Gajanan M. Sabnis Maher K. Tadros William L. Gamble Michael E. Kreger Peter Meza John R. Salmons John W. Wallace Roger Green LeRoy A. Lutz Denis Mitchell Thomas C. Schaeffer Sharon L. Wood Consulting Members Richard D. Gaynor Edward S. Hoffman Richard A. Ramsey Jacob S. Grossman Francis J. Jacques Irwin J. Speyer John M. Hanson Alan H. Mattock INTRODUCTION 318/318R-1. BUILDING CODE REQUIREMENTS FOR. STRUCTURAL CONCRETE (ACI 318-99). AND COMMENTARY (ACI 318R-99). REPORTED BY ACI COMMITTEE 318. The code portion of this document covers the proper design and construction of buildings of STRUCTURAL concrete. The code has been written in such form that it may be adopted by reference in a general BUILDING code and earlier editions have been widely used in this manner.

3 Among the subjects covered are: drawings and specifications; inspection; materials; durability REQUIREMENTS ; concrete quality, mixing, and placing; formwork; embedded pipes; and construction joints; reinforcement details; analysis and design; strength and serviceability; flexural and axial loads; shear and torsion; development and splices of reinforce- ment; slab systems; walls; footings; precast concrete; composite flexural members; prestressed concrete; shells and fold- ed plate members; strength evaluation of existing structures; special provisions for seismic design; STRUCTURAL plain concrete; an alternate design method in Appendix A; unified design provisions in Appendix B; and alternative load and strength reduction factors in Appendix C. The quality and testing of materials used in construction are covered by reference to the appropriate ASTM standard specifications.

4 Welding of reinforcement is covered by reference to the appropriate ANSI/AWS standard. Because the ACI BUILDING Code is written as a legal document so that it may be adopted by reference in a general build- ing code, it cannot present background details or suggestions for carrying out its REQUIREMENTS or intent. It is the function of this commentary to fill this need. The commentary discusses some of the considerations of the committee in developing the code with emphasis given to the explanation of new or revised provisions that may be unfamiliar to code users. References to much of the research data referred to in preparing the code are cited for the user desiring to study indi- vidual questions in greater detail. Other documents that provide suggestions for carrying out the REQUIREMENTS of the code are also cited. Keywords: admixtures; aggregates; anchorage ( STRUCTURAL ); beam-column frame; beams (supports); BUILDING codes; cements; cold weather construction; col- umns (supports); combined stress; composite construction (concrete and steel); composite construction (concrete to concrete); compressive strength; concrete construction; concretes; concrete slabs; construction joints; continuity ( STRUCTURAL ); contraction joints; cover; curing; deep beams; deflections; drawings; earth- quake resistant structures; embedded service ducts; flexural strength; floors; folded plates; footings; formwork (construction); frames; hot weather construction.

5 Inspection; isolation joints; joints (junctions); joists; lightweight concretes; loads (forces); load tests ( STRUCTURAL ); materials; mixing; mix proportioning; modulus of elasticity; moments; pipe columns ; pipes (tubing); placing; plain concrete; precast concrete; prestressed concrete; prestressing steels; quality control; rein- forced concrete; reinforcing steels; roofs; serviceability; shear strength; shearwalls; shells ( STRUCTURAL forms); spans; specifications; splicing; strength; strength analysis; stresses; STRUCTURAL analysis; STRUCTURAL concrete; STRUCTURAL design; STRUCTURAL integrity; T-beams, torsion; walls; water; welded wire fabric. ACI 318-99 was adopted as a standard of the American Concrete Institute all responsibility for the stated principles. The Institute shall not be liable for March 18, 1999 to supersede ACI 318-95 in accordance with the Institute's any loss or damage arising therefrom.

6 Reference to this commentary shall not standardization procedure. be made in contract documents. If items found in this Commentary are de- Vertical lines in the margins indicate the 1999 code and commentary sired by the Architect/Engineer to be a part of the contract documents, they changes. shall be restated in mandatory language for incorportation by the Architect/. A complete metric companion to ACI 318/318R has been developed, Engineer. 318M/318RM; therefore no metric equivalents are included in this document. Copyright 1999, American Concrete Institute. ACI Committee Reports, Guides, Standard Practices, and Commentaries All rights reserved including rights of reproduction and use in any form are intended for guidance in planning, designing, executing, and inspecting or by any means, including the making of copies by any photo process, or construction.

7 This Commentary is intended for the use of individuals who by any electronic or mechanical device, printed or written or oral, or record- are competent to evaluate the significance and limitations of its content and ing for sound or visual reproduction or for use in any knowledge or retrieval recommendations and who will accept responsibility for the application of system or device, unless permission in writing is obtained from the copy- the material it contains. The American Concrete Institute disclaims any and right proprietors. ACI 318 BUILDING Code and Commentary 318/318R-2 INTRODUCTION. The 1999 ACI BUILDING Code and Commentary are presented in a side-by-side column format, with code text placed in the left column and the corresponding commentary text aligned in the right column. To further distin- guish the Code from the Commentary, the Code has been printed in Helvetica, the same type face in which this paragraph is set.

8 Vertical lines in the margins indicate changes from ACI 318-95. This paragraph is set in Times Roman, and all portions of the text exclusive to the Commentary are printed in this type face. Commentary section numbers are preceded by an R to further distinguish them from Code section numbers. INTRODUCTION necessary to protect the public as stated in the code. Howev- er, lower standards are not permitted. This commentary discusses some of the considerations of Committee 318 in developing the provisions contained in The commentary directs attention to other documents that BUILDING Code REQUIREMENTS for STRUCTURAL Concrete (ACI provide suggestions for carrying out the REQUIREMENTS and in- 318-99), hereinafter called the code or the 1999 code. Em- tent of the code. However, those documents and the com- mentary are not a part of the code.

9 Phasis is given to the explanation of new or revised provi- sions that may be unfamiliar to code users. In addition, The code has no legal status unless it is adopted by the gov- comments are included for some items contained in previous ernment bodies having the police power to regulate BUILDING editions of the code to make the present commentary inde- design and construction. Where the code has not been adopt- pendent of the commentary for ACI 318-95. Comments on ed, it may serve as a reference to good practice even though specific provisions are made under the corresponding chap- it has no legal status. ter and section numbers of the code. The code provides a means of establishing minimum stan- The commentary is not intended to provide a complete his- dards for acceptance of designs and construction by a legally torical background concerning the development of the ACI appointed BUILDING official or his designated representatives.

10 BUILDING Code,* nor is it intended to provide a detailed r - The code and commentary are not intended for use in settling sum of the studies and research data reviewed by the com- disputes between the owner, engineer, architect, contractor, or mittee in formulating the provisions of the code. However, their agents, subcontractors, material suppliers, or testing agen- references to some of the research data are provided for those cies. Therefore, the code cannot define the contract responsibil- who wish to study the background material in depth. ity of each of the parties in usual construction. General references requiring compliance with the code in the job speci- As the name implies, BUILDING Code REQUIREMENTS for fications should be avoided since the contractor is rarely in a po- STRUCTURAL Concrete (ACI 318-99) is meant to be used as sition to accept responsibility for design details or construction part of a legally adopted BUILDING code and as such must dif- REQUIREMENTS that depend on a detailed knowledge of the de- fer in form and substance from documents that provide de- sign.