352R-02 Recommendations for Design of Beam …

1 ACI 352R-02 supersedes ACI 352r -91(Reapproved 1997) and became effectiveJune 18, 2002, American Concrete rights reserved including rights of reproduction and use in any form or by anymeans, including the making of copies by any photo process, or by electronic ormechanical device, printed, written, or oral, or recording for sound or visual reproduc-tion or for use in any knowledge or retrieval system or device, unless permission inwriting is obtained from the copyright proprietors. ACI Committee Reports, Guides, Standard Practices,and Commentaries are intended for guidance in plan-ning, designing, executing, and inspecting document is intended for the use of individuals whoare competent to evaluate the significance and limita-tions of its content and Recommendations and who willaccept responsibility for the application of the materialit contains.

2 The American Concrete Institute disclaimsany and all responsibility for the stated principles. TheInstitute shall not be liable for any loss or damagearising to this document shall not be made incontract documents. If items found in this document aredesired by the Architect/Engineer to be a part of thecontract documents, they shall be restated in mandatorylanguage for incorporation by the Architect/Engineer. 352r -1 Recommendations for Design ofBeam-Column Connections inMonolithic Reinforced Concrete StructuresACI 352R-02 Recommendations are given for member proportions, confinement of thecolumn core in the joint region, control of joint shear stress, ratio of column-to- beam flexural strength at the connection, development of reinforcingbars, and details of columns and beams framing into the joint.

3 Normal typeis used for Recommendations . Commentary is provided in italics to amplifythe Recommendations and identify available reference Recommendations are based on laboratory testing and field studiesand provide a state-of-the-art summary of current information. Areas needingresearch are identified. Design examples are presented to illustrate the useof the Design : anchorage; beam ; beam -column; bond; columns ; confinedconcrete; high-strength concrete; joints; reinforced concrete; reinforce-ment; reinforcing steel; shear strength; shear 1 Introduction, scope, and definitions,p. DefinitionsChapter 2 Classification of beam -column connections, p.

4 Loading Connection geometryChapter 3 Design considerations, p. Design forces and Critical Member flexural ServiceabilityChapter 4 Nominal strength and detailing requirements, p. Column longitudinal Joint transverse Joint shear for Type 1 and Type 2 Development of beam transverse reinforcementReported by Joint ACI-ASCE Committee 352 James R. CagleyJames M. LaFave*Patrick PaultreMarvin E. CriswellDouglas D. LeeM. Saiid SaiidiCatherine E. FrenchRoberto T. LeonBahram M. ShahroozLuis E. GarciaDonald F. MeinheitJohn W. WallaceT. Russell Gentry*Jack P. MoehleJames K. WightTheodor KrauthammerStavroula J. PantazopoulouLoring A. Wyllie, E. Kreger*John F.

5 Bonacci*ChairSergio M. Alcocer Secretary*Member of editorial subcommittee. Chair of editorial COMMITTEE REPORTC hapter 5 Notation, p. 352r -16 Chapter 6 References, p. Referenced standards and Cited referencesAppendix A Areas needing research, p. Effect of eccentric beams on Lightweight aggregate concrete in Limit on joint Behavior of indeterminate Distribution of plastic Innovative joint Special joint configurations and Joints in existing structuresAppendix B Design examples, p. 352r -20 CHAPTER 1 INTRODUCTION, SCOPE,AND IntroductionThese Recommendations are for determining proportions, Design , and details of monolithic beam -column connectionsin cast-in-place concrete frame construction.

6 The recom-mendations are written to satisfy strength and ductilityrequirements related to the function of the connection withina structural report considers typical beam -column connections incast-in-place reinforced concrete buildings, as shown inFig. Although the Recommendations are intended toapply primarily to building structures, they can be extendedto other types of frame structures when similar loading andstructural conditions exist. Design examples illustrating theuse of these Recommendations are given in Appendix excluded from these Recommendations areslab-column connections, which are the topic of ACI ,and precast structures where connections are made near thebeam-to-column material presented herein is an update of a previousreport from ACI 352r .

7 Research information available inrecent references and Chapter 21 of ACI 318-02 wasreviewed during the updating of these provisions. Modifica-tions have been made to include higher-strength concrete,slab-steel contribution to joint shear, roof-level connections,headed reinforcement used to reduce steel congestion,connections in wide- beam systems, and connections witheccentric beams. This report addresses connections in bothseismic and nonseismic regions, whereas Chapter 21 of ACI318-02 only addresses connections for seismic regions. Anumber of Recommendations from previous editions of thisreport have been adopted in Chapter 21 of ACI 318-02 forseismic Design .

8 Recommendations in this report for connec-tions in earthquake-resisting structures are intended to comple-ment those in the 1999 edition of Chapter 21 of ACI 318,covering more specific connection types and providing moredetail in some many designs, column sizes may be defined by the require-ments of the connection Design . Attention is focused on theconnection to promote proper structural performance underall loading conditions that may reasonably be expected tooccur and to alert the designer to possible ScopeThese Recommendations apply only to structures usingnormalweight concrete with a compressive strength fc notexceeding 15,000 psi (100 MPa) in the consideration of recent research results of connec-tions with concrete compressive strengths of up to 15,000 psiFig.

9 Typical beam -to-column connections (slabs not shown for clarity). Wide-beamcases not CONNECTIONS IN MONOLITHIC CONCRETE STRUCTURES352R-3(100 MPa), ACI Committee 352 has extended the limits ofthe Recommendations to include high-strength concrete(Guimaraes, Kreger, and Jirsa 1992; Saqan and Kreger1998; Sugano et al. 1991). The committee believes thatfurther research demonstrating the performance and designrequirements of connections with lightweight-aggregateconcrete is required before the scope of these recommenda-tions can extend beyond normalweight concrete. These recom-mendations are applicable to structures in which mechanicalsplices are used, provided that the mechanical splices meet therequirements of Section of ACI 318-02 and the recom-mendations of the Commentary to Section of ACI DefinitionsA beam -column joint is defined as that portion of thecolumn within the depth of the deepest beam that frames intothe column.

10 Throughout this document, the term joint is usedto refer to a beam -column connection is the joint plus the columns , beams, and slabadjacent to the transverse beam is one that frames into the joint in adirection perpendicular to that for which the joint shear isbeing 2 CLASSIFICATION OF beam -COLUMN Loading conditionsStructural connections are classified into two categories Type 1 and Type 2 based on the loading conditions for theconnection and the anticipated deformations of theconnected frame members when resisting lateral Type 1 A Type 1 connection is composed ofmembers designed to satisfy ACI 318-02 strength require-ments, excluding Chapter 21, for members without signifi-cant inelastic Type 2 In a Type 2 connection.