318-05/318R-05 Building Code Requirements for Structural ...

1 James K. WightChairBasile G. RabbatSecretarySergio M. AlcocerLuis E. GarciaDominic J. KellyMyles A. MurrayFlorian G. BarthS. K. GhoshGary J. KleinJulio A. RamirezRoger J. BeckerLawrence G. GriffisRonald KlemencicThomas C. SchaefferKenneth B. BondyDavid P. GustafsonCary S. KopczynskiStephen J. SeguirantJohn E. BreenD. Kirk HarmanH. S. LewRoberto StarkJames R. CagleyJames R. HarrisColin L. LoboEric M. TollesMichael P. CollinsNeil M. HawkinsLeslie D. MartinThomas D. VertiW. Gene CorleyTerence C. HollandRobert F. MastSharon L. WoodCharles W. DolanKenneth C. HoverSteven L. McCabeLoring A. WyllieAnthony E. FioratoPhillip J. IversonW. Calvin McCallFernando V. YanezCatherine E. FrenchJames O. JirsaJack P. MoehleSubcommittee MembersNeal S. AndersonJuan P. CovarrubiasMichael E. KregerVilas S. MujumdarGuillermo SantanaMark A. AschheimRobert J. FroschDaniel A. KuchmaSuzanne D. NakakiAndrew ScanlonJohn F. BonacciHarry A. GleichLeRoy A. LutzTheodore L. NeffJohn F. StantonJoAnn P. BrowningJavier F.

2 Horvilleur James G. MacGregorAndrzej S. NowakFernando R. StucchiNicholas J. CarinoR. Doug HootonJoe MaffeiRandall W. PostonRaj ValluvanNed M. ClelandL. S. Paul JohalDenis MitchellBruce W. RussellJohn W. WallaceRonald A. CookConsulting MembersC. Raymond HaysRichard C. MeiningerCharles G. SalmonBUILDING CODE Requirements FOR Structural CONCRETE (ACI 318-05) AND COMMENTARY (ACI 318R-05)REPORTED BY ACI COMMITTEE 318 ACI Committee 318 Structural Building Code DeceasedACI 318-05 is deemed to satisfy ISO 19338, Performance and Assessment Requirements for Design Standards on StructuralConcrete, Reference Number ISO (E). Also Technical Corrigendum 1: STANDARD/COMMITTEE REPORTINTRODUCTION318/318R-1 ACI 318 Building Code and CommentaryPREFACEThe code portion of this document covers the design and construction of Structural concrete used in buildings andwhere applicable in nonbuilding the subjects covered are: drawings and specifications; inspection; materials; durability Requirements ; concretequality, mixing, and placing; formwork; embedded pipes; construction joints; reinforcement details; analysis anddesign; 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 andfolded plate members; strength evaluation of existing structures; special provisions for seismic design; Structural plainconcrete; strut-and-tie modeling in Appendix A.

3 Alternative design provisions in Appendix B; alternative load andstrength-reduction factors in Appendix C; and anchoring to concrete in Appendix quality and testing of materials used in construction are covered by reference to the appropriate ASTM standardspecifications. Welding of reinforcement is covered by reference to the appropriate ANSI/AWS of the code include adoption by reference in general Building codes, and earlier editions have been widely used inthis manner. The code is written in a format that allows such reference without change to its language. Therefore, back-ground details or suggestions for carrying out the Requirements or intent of the code portion cannot be included. Thecommentary is provided for this purpose. Some of the considerations of the committee in developing the code portion arediscussed within the commentary, with emphasis given to the explanation of new or revised provisions. Much of theresearch data referenced in preparing the code is cited for the user desiring to study individual questions in greaterdetail.

4 Other documents that provide suggestions for carrying out the Requirements of the code are also : 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; concreteconstruction; 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;inspection; isolation joints; joints (junctions); joists; lightweight concretes; loads (forces); load tests ( Structural ); materials; mixing; mix proportioning; modulusof 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; strengthanalysis; stresses; Structural analysis; Structural concrete; Structural design; Structural integrity; T-beams; torsion; walls; water; welded wire 318-05 was adopted as a standard of the American Concrete InstituteOctober 27, 2004 to supersede ACI 318-02 in accordance with the Insti-tute s standardization complete metric companion to ACI 318/318R has been developed,318M/318RM; therefore no metric equivalents are included in this Committee Reports, Guides, Standard Practices, and Commentariesare intended for guidance in planning, designing, executing, and inspectingconstruction.

5 This Commentary is intended for the use of individuals whoare competent to evaluate the significance and limitations of its content andrecommendations and who will accept responsibility for the application ofthe material it contains. The American Concrete Institute disclaims any andall responsibility for the stated principles. The Institute shall not be liable forany loss or damage arising therefrom. Reference to this commentary shall notbe made in contract documents. If items found in this Commentary aredesired by the Architect/Engineer to be a part of the contract documents, theyshall be restated in mandatory language for incorporation by the 2005, American Concrete rights reserved including rights of reproduction and use in any formor by any means, including the making of copies by any photo process, orby any electronic or mechanical device, printed or written or oral, orrecording for sound or visual reproduction or for use in any knowledge orretrieval system or device, unless permission in writing is obtained from thecopyright CODE Requirements FOR Structural CONCRETE (ACI 318-05)AND COMMENTARY (ACI 318R-05)REPORTED BY ACI COMMITTEE 3182 TABLE OF CONTENTSACI 318 Building Code and CommentaryCONTENTSINTRODUCTION.

6 7 CHAPTER 1 GENERAL Requirements .. Drawings and specifications .. Inspection .. Approval of special systems of design or construction .. 18 CHAPTER 2 NOTATION AND DEFINITIONS .. Notation .. Definitions .. 28 CHAPTER 3 MATERIALS .. Tests of materials .. Cements .. Aggregates .. Water .. Steel Admixtures .. Storage of Referenced standards .. 45 CHAPTER 4 DURABILITY Requirements .. Water-cementitious material ratio .. Freezing and thawing exposures .. Sulfate exposures .. Corrosion protection of reinforcement .. 54 CHAPTER 5 CONCRETE QUALITY, MIXING, AND PLACING .. General .. Selection of concrete proportions .. Proportioning on the basis of field experience or trial mixtures, or both .. Proportioning without field experience or trial Average strength reduction .. Evaluation and acceptance of Preparation of equipment and place of Mixing .. Conveying .. Depositing .. Curing .. Cold weather Hot weather Requirements .

7 72 CHAPTER 6 FORMWORK, EMBEDDED PIPES, AND CONSTRUCTION JOINTS .. Design of formwork .. Removal of forms, shores, and reshoring .. Conduits and pipes embedded in concrete .. Construction joints .. 76 CHAPTER 7 DETAILS OF REINFORCEMENT .. Standard Minimum bend diameters .. Surface conditions of reinforcement .. Placing reinforcement .. 81 TABLE OF CONTENTS3 ACI 318 Building Code and Spacing limits for Concrete protection for reinforcement .. Special reinforcement details for columns .. Connections .. Lateral reinforcement for compression members .. Lateral reinforcement for flexural members .. Shrinkage and temperature reinforcement .. Requirements for Structural integrity .. 92 CHAPTER 8 ANALYSIS AND DESIGN GENERAL Design methods .. Loading .. Methods of analysis .. Redistribution of negative moments in continuous flexural members .. Modulus of Stiffness .. Span length .. Columns .. Arrangement of live load .. T-beam construction.

8 Joist construction .. Separate floor finish .. 103 CHAPTER 9 STRENGTH AND SERVICEABILITY General .. Required strength .. Design strength .. Design strength for Control of deflections .. 111 CHAPTER 10 FLEXURE AND AXIAL LOADS .. Scope .. Design General principles and Requirements .. Distance between lateral supports of flexural Minimum reinforcement of flexural members .. Distribution of flexural reinforcement in beams and one-way slabs .. Deep Design dimensions for compression members .. Limits for reinforcement of compression members .. Slenderness effects in compression members .. Magnified moments General .. Magnified moments Nonsway Magnified moments Sway Axially loaded members supporting slab system .. Transmission of column loads through floor system .. Composite compression Bearing 144 CHAPTER 11 SHEAR AND TORSION .. Shear strength .. Lightweight concrete .. Shear strength provided by concrete for nonprestressed Shear strength provided by concrete for prestressed Shear strength provided by shear reinforcement.

9 Design for torsion .. Deep Special provisions for brackets and 1764 TABLE OF CONTENTSACI 318 Building Code and Special provisions for Transfer of moments to columns .. Special provisions for slabs and 181 CHAPTER 12 DEVELOPMENT AND SPLICES OF REINFORCEMENT .. Development of reinforcement General .. Development of deformed bars and deformed wire in tension .. Development of deformed bars and deformed wire in compression .. Development of bundled bars .. Development of standard hooks in Mechanical Development of welded deformed wire reinforcement in Development of welded plain wire reinforcement in Development of prestressing strand .. Development of flexural reinforcement Development of positive moment reinforcement .. Development of negative moment reinforcement .. Development of web reinforcement .. Splices of reinforcement General .. Splices of deformed bars and deformed wire in tension .. Splices of deformed bars in compression.

10 Special splice Requirements for columns .. Splices of welded deformed wire reinforcement in Splices of welded plain wire reinforcement in tension .. 218 CHAPTER 13 TWO-WAY SLAB SYSTEMS .. Definitions .. Slab Openings in slab systems .. Design Direct design method .. Equivalent frame method .. 233 CHAPTER 14 WALLS .. General .. Minimum reinforcement .. Walls designed as compression members .. Empirical design method .. Nonbearing Walls as grade beams .. Alternative design of slender walls .. 241 CHAPTER 15 FOOTINGS .. Loads and reactions .. Footings supporting circular or regular polygon shaped columns or pedestals .. Moment in footings .. Shear in footings .. Development of reinforcement in footings .. Minimum footing depth .. Transfer of force at base of column, wall, or reinforced pedestal .. Sloped or stepped footings .. Combined footings and mats .. 249 CHAPTER 16 PRECAST CONCRETE .. General .. 251 TABLE OF CONTENTS5 ACI 318 Building Code and Distribution of forces among members.