ACI-209R-1992-混凝土结构蠕变、干缩和温度效应预测

ACI209R-92(Reapproved1997)PredictionofCreep,Shrinkage,andTemperatureEffectsinConcreteStructuresReportedbyACICommittee209JamesA.Rhodes?DomingoJ.Carreira++Chairman,Committee209Chairman,SubcommitteeIIJamesJ.BeaudoinDanE.Brauson*tBruceR.GambleH.G.GeymayerBrijB.GoyaltBrianB.HopeJohnR.KeetontClydeE.KeslerWilliamR.LormanJackA.Means?BernardLMeyersl-R.H.MillsK.W.NasserA.M.NevilleFredericRoll?JohnTimuskMichaelA.WardCorrespondingMembers:JohnW.Dougill,H.K.HilsdorfCommitteemembersvotingonthe1992revisions:MarwanA.DayeChairmanAkthemAl-ManaseerJamesJ.BeaudoiuDanE.BransonDomingoJ.CarreiraJenn-ChuanChemMenashiD.CohenRobertLDayChungC.Fu1SatyendraK.GhoshBrijB.GoyalWillHansenStacyK.HirataJoeHutererHeshamMarzoukBernardL.MeyersKarimW.NasserMikaelPJ.OlsenBaldevR.SethKwok-NamShiuLiiiaPanula$*MemberofSubcommitteeII,whichpreparedthisreporttMemberofSubcommitteeIIS=-=dThisreportreviewsthemethodsforpredictingcreep,shrinkageandtemperatureeffectsinconcretestructures.Itpresentsthedesignerwithaunifiedanddigestedapproachtotheproblemofvolumechangesinconcrete.Theindividualchaptershavebeenwritteninsuchawaythattheycanbeusedalmostindependentlyfromtherestofthereport.ThereportisgenerallyconsistentwithACI318andincludesmaterialindicatedintheCode,butnotspecificallydefinedtherein.Keywords:beams(supports);buckling;camber;compositeconstruction(concretetoconcrete);compressivestrength;concretes;concreteslabs;cracking(fracturing);creepproperties;curing;deflection;flatconcreteplates;flexuralstrength;girders;lightweight-aggregateconcretes;modulusofelasticity;momentsofinertia;precastconcrete;prestressedconcrete:prestressloss;reinforcedconcrete:shoring;shrinkage;strains;stressrelaxation;structuraldesign;temperature;thermalexpansion;two-wayslabs:volumechange;warpage.ACICommitteeReports,Guides,StandardPractices,andCommentariesareintendedforguidanceindesigning,plan-ning,executing,orinspectingconstructionandinpreparingspecifications.ReferencestothesedocumentsshallnotbemadeintheProjectDocuments.IfitemsfoundinthesedocumentsaredesiredtobeapartoftheProjectDocu-ments,theyshouldbephrasedinmandatorylanguageandincorporatedintotheProjectDocuments.JCONTENTSChapter1--General,pg.209R-2l.l-Scope1.2-Natureoftheproblem1.3-DefinitionsoftermsChapter2-Materialresponse,pg.209R-42.1-Introduction2.2-Strengthandelasticproperties2.3-Theoryforpredictingcreepandshrinkageofcon-crete2.4-RecommendedcreepandshrinkageequationsforstandardconditionsThe1992revisionsbecameeffectiveMar.1,1992.Therevisionsconsistedofminoreditorialchangesandtypographicalcorrections.Copyright81982AmericanConcreteInstitute.Allrightsreservedincludingrightsofreproductionanduseinanyformorbyanymeans,includingthemakingofcopiesbyanyphotoprocess,orbyanyelec-tronicormechanicaldevice,printedorwrittenororal,orrecordingforsoundorvisualreproductionorforuseinanyknowledgeorretrievalsystemordevice,unlesspermissioninwritingisobtainedfromthecopyrightproprietors.CopyrightAmericanConcreteInstituteProvidedbyIHSunderlicensewithACINotforResaleNoreproductionornetworkingpermittedwithoutlicensefromIHS--``,`,-`-`,,`,,`,`,,`---209R-2ACICOMMITTEEREPORT2.5-Correctionfactorsforconditionsotherthanthestandardconcretecomposition2.6-Correctionfactorsforconcretecomposition2.7-Example2.8-Othermethodsforpredictionofcreepandshrinkage2.9-Thermalexpansioncoefficientofconcrete2.10-StandardscitedinthisreportChapter3-Factorsaffeatingthestructuralresponse-assumptionsandmethodsofanalysis,pg.209R-123.1-Introduction3.2-Principalfactsandassumptions3.3-Simplifiedmethodsofcreepanalysis3.4-Effectofcrackinginreinforcedandprestressedmembers3.5-Effectivecompressionsteelinflexuralmembers3.6-Deflectionsduetowarping3.7-Interdependencybetweensteelrelaxation,creepandshrinkageofconcreteChapter4-Responseofstructuresinwhichtime-changeofstressesduetocreep,shrinkageandtem-peratureisnegligible,pg.209R-164.1-Introduction4.2-Deflectionsofreinforcedconcretebeamandslab4.3-Deflectionofcompositeprecastreinforcedbeamsinshoredandunshoredconstructions4.4-Lossofprestressandcamberinnoncompositeprestressedbeams4.5-Lossofprestressandcamberofcompositepre-castandprestressed-beamsunshoredandshoredconstructions4.6-Example4.7-Deflectionofreinforcedconcreteflatplatesandtwo-wayslabs4.8-Time-dependentsheardeflectionofreinforcedconcretebeams4.9-Comparisonofmeasuredandcomputeddeflec-tions,cambersandprestresslossesusingpro-ceduresinthischapterChapter5-Responseofstructureswithsignigicanttimechangeofstress,pg.209R-225.l-Scope5.2-Concreteagingandtheage-adjustedeffectivemodulusmethod5.3-Stressrelaxationafterasuddenimposeddefor-mation5.4-Stressrelaxationafteraslowly-imposeddefor-mation5.5-Effectofachangeinstaticalsystem5.6-Creepbucklingdeflectionsofaneccentricallycompressedmember5.7-Twocantileversofunequalageconnectedattimetbyahinge5.8lossofcompressioninslabanddeflectionofasteel-concretecompositebeam5.9-Othercases5.10-ExampleAcknowledgements,pg.209R-25References,pg.209R-25Notation,pg.209R-29Tables,pg.209R-32CHAPTERl-GENERALl.l-ScopeThisreportpresentsaunifiedapproachtopredictingtheeffectofmoisturechanges,sustaine