土木工程专业毕业设计外文文献及翻译

a,a,英文原文：ofRCwithdeficienciesCFRP*,Antonio

b

DepartmentofStructuralofAlexandriaEgyptb

DepartmentofCivilEngineering,UniversityofRolla,Rolla,MO28April1999;inrevisedform30October2001;accepted102002AbstractThestudyexaminesthemodesoffailureofrectangularsimplyreinforceddesignedwithshearThesewereexternallybondedfiber(CFRP)sheetsandinlaboratory.Theprogramoftwelvefull-scaleRCbeamstofailinThevariablesinvestigatedwithinthisprogramstirrups,theshearspan-to-effectivedepthwellamountanddistributionofexperimentalindicatedthecontributionofexternallytocapacitywassignificant.TheshearcapacitywasalsoshowntobedependentuponvariablesTestresultswereusedashearapproach,whicheq\o\ac(○,C)eq\o\ac(○,)2002Ltd.AllKeywords:Rehabilitation;fiberreinforced1.polymer(FRP)compositesystems,composedofembeddedinapolymericmatrix,beforofreinforcedcon-crete(RC)members[17].RCbeamsandinofTheofanRCbeamclearlydifferentfromitsflexuralfailure.InthefailswithoutsufficientshearwidertheflexuralcracksTheobjectivesofprogramwereto:-1-offailuresimplyrectangularRCwithsheardeficien-ciesafterwithexternallyCFRPfactorsthatinfluencecapacityofstrengthenedsuchas:stirrups,shearspan-to-effectiveratio),amountdistributionofCFRP.thedatabaseonwithexternallybondedFRPtheproposedbyauthors[9].For12full-scale,beamsdesignedfailinshearwerestrengthenedwithschemes.Thesemembersweretestedassimpleusingafour-pointconfigurationwithtwodifferentratios.2.Experimentalprogram2.1.TestspecimensandmaterialsTwelvewithaspanof3050mm.andof150-mm-widewereThespecimensweregroupedseriesSWandSOonofintheshearspanofinterest.SWconsistedofTheandofspecimensseriesareillustratedinInthiswerelongitudinalreinforcementwithtwoattwoatfaceofthetoinduceshearspecimensreinforcedwith10-mmthroughouttheirThestirrupsinshearofrighthalf,wastoallowfailurethatconsistedofbeamwhichsamelongitudinalreinforcementasforserieswereprovidedinthehalfspaninSWwasintosubgroupstospan-to-effectivedepthratio.Thiswastoa/d=3and4,resultinginthefollowingfoursubgroups:SW3;SW4;SO3;-2-TheofusedspecimenslistedinofthepreparationCFRPinstallation[10].2.2.StrengtheningschemesfromeachseriesSW4-1,wasleftwithoutacontrolwhereasspecimenswerestrengthenedwithexternallybondedCFRPsheetsfollowingthreedifferentasinInSW3,specimenSW3-2wasstrengthenedwithCFRPpliesperpendicularfiberdirectionsThefirstplyinformofcontinuousU-wrapwithfiberperpendiculartolongitudinalaxisofthe(90°).Thesecondplywasonsidesofspecimenwithfibertobeam0°ply0°ply]wastoinvestigatetheimpactofadditionalhorizontalonInSW4,specimenSW4-2wasstrengthenedwithCFRPpliesperpendicularfiberforSW3-2.werestrengthenedinseriesSO3-2strengthenedwithone-plystripsinformofwith50mmwithspacingof125mm.wasamannersimilartoofbut-3-withwidthequal75mm.SO3-4wasstrengthenedwithone-plycontinuousU-wrap(90°).SO3-5strengthenedwithCFRP(90°/0°)similartospecimensSW3-2SW4-2.Inserieswerestrengthened.SO4-2strengthenedwithone-plyCFRPstripsinformofU-wrapsimilartospecimenSO3-2.SO4-3wasstrengthenedwithone-plyU-wrap(90°)toSO3-4.Configurationdetailsforbeamspecimens.-4-of2.3.Testset-upandinstrumentationAllspecimenstestedsimplespantofour-pointasin3.Atestingwith1800KNwasintoapplyaconcentratedonsteelbeamtoloads.Thewasappliedincycles,usuallycyclebeforefollowedbythreewithlastoneuptoThedeflectioncurvesshowninpaperofthesecycles.lineardifferential(LVDTs)usedforeachmonitorverticalatvariouslocationsinFig.3.TwoLVDTswereoneachsideofspecimen.werelocatedthetosupport-5-Fig.3.representationoftestfor(a)SW3-1,SW3-2.Foreachofsixstrainwereattachedtomonitorstirrupduringloadingasingaugesweretotheontheofstrengthenedmonitorinstraingaugeswereinverticallocatedthewithdistancesof300andfromsupportforseriesSW3andspecimensofseriesSW4gaugesatdistanceof375,mm,fromsupport.3.ResultsanddiscussionInfollowingisalwaystospanspanof3.1.SeriesSW3inspecimenSW3-1weretomiddleoftheshearspanwhentheloadapproximately90kN.theloadincreased,shearformeduptofinalfailureatof253InSW3-2withCFRP(90°nowerevisibleonoroftestFRPwrapping.Howeveralongitudinalsplittingtheofbeamofapproximately320kN.-6-FailureseriesSW3specimens.ThethelocationofappliedextendedThespecimenfailedbysplitting(seeFig.4b)atloadofkN.Thiswasof40%incapacitycomparedtocontrolSW3-1.Thesplittingtorelativelylongitudinalstressdevelopedattopofthespecimen,whichcreatedledthesplittingInaddition,relativelyamountoflongitudinalreinforcementwithforshearCFRPprobablythisofloadvs.deflectioncurvesforSW3-1SW3-2areillustratedin5,theadditionalbyCFRP.-7-Appliedvs.forTheverticalstrainfailureinSW3-2approximately0.0023mm/mm,whichtoofthereportedCFRPultimateThisvalueisnotanitgreatlyonlocationofgaugeswithtocrack.However,thethatifsplittingdidthecapacitycouldhavehigherComparisonbetweenlocalstirrupstrainsinspecimensSW3-2areshownin6.wereatdistanceof300andmmfromthesupport,resultsthestirrupsdidatforbothThestrains(andintheofSW3-2were,inofSW3-1atsameofloadingtheeffectof-8-AheforSW3-1SW3-2.3.2.SeriesSW4InSW4-1,thefirstdiagonalcrackformedintotalloadof75kN.Asloadincreased,additionalshearthroughoutshearFailureoftheoccurredwhenthetotalreached200kN.Thisaof20%inshearcapacitytospecimenSW3-1withratio=3.Appliedvs.forInSW4-2,failurewascontrolledbyconcretesplittingsimilartospecimenThetotalappliedatultimatewaskNwithanincreaseincapacitycomparedtocontrolSW4-1.Inaddition,thestrainsinthestirrupsforSW4-2lessofSW4-1.Thevs.mid-spanforbeamsSW4-2areinItbenotedthatingreaterdeflectionwhentospecimenSW4-1.WhencomparingresultsofSW3specimenstoofseriestheultimateofSW3-2SW4-2wasthesame.theofspecimenSW3-2(=3)duetheofCFRPreinforcementkN,whileSW4-2(a/d=4)waskN.ThisthatthecontributionexternalCFRPreinforcementmaybebytheaydratiodecreasewitharatio.forstrengthened(SW3-2andsheetsdidnotdebondfromultimatethisthatprovideifthedidnotfailedbysplitting.-9-3.3.SeriesSO3forSO3detailsthedeflectionThefailureofspecimenSO3-1compression.ofthespecimenoccurredatappliedloadof154ThiswasaofshearcapacitybykNthespecimenSW3-1totheofstirrups.InthepatterninspecimenSW3-1wasdifferentfromofspecimenInSW3-1,ofbetterdistributionofdiagonalcrackstheInspecimenstrengthenedwithCFRPstrips125thefirstatanof100kN.ThecrackpropagatedloadinmannerofspecimenfailureoccurredtodebondingofthestripsoverdiagonalwithspalledconcreteattachedtotheCFRPTheultimateload262witha70%incapacityoverspecimenCFRPverticalatin(i.e.28%theultimatestrain),whichthenotreachstrengthenedwith75-mmCFRPstripsaresultofCFRPataloadof266Noincreaseincapacitywasnotedtomaximum-recordedverticalatfailurewasmmymm(i.e.ofstrain).SO3-4,strengthenedwithacontinuousU-wrap(908),failedaresultofatanloadof289Resultsthatspecimenincreaseincapacityof87,108.5%specimensAppliedloadvs.verticalCFRPforininwhichstraingaugessg1,werewithdistancesof300andmmfromthe10thattheCFRPstrainzeropriortodiagonalcrackthen-10slowlyuntilthereachedaloadintheoftheultimatestrengthofcontrolAtthisstrainsignificantlyuntilverticalatfailurewasapproxi-matelymm/mm.WhencomparingofbeamstheCFRPamounttostrengthenspecimenofthatforSO3-2.Onlya10%increasecapacitywasfortheadditionalused.thatifFRPisnotused,isanFRPwhichtheeffectisAprevious[11]anendanchorsystem,modeofFRPcouldbeareconsistentwithof[7],whichwasareviewofavailableintheliterature,indicatedcontributionofFRPtoshearcapacityalmostlinearly,by

f

E

f

(fistheFRPareafractionE

f

theelasticupBeyondvalue,theofFRPceasestobeInspecimentheuseofplythecontinuousU-wrap(i.e.90°/0°)inaconcretesplittingfailureratherthanThefailureoccurredtotalloadof339witha120%increaseinshearcapacitytoSO3-1.Thewithtwoperpendicularplies90°/0°)inaincreasecapacitycomparedtowithplyin90°orientation(i.e.TheCFRPverticalatmm/mm.BycomparingtheresultsofSW3-2SO3-5,samea/dratioandstrengtheningwithdifferentsteelshearreinforcement,(i.e.177andkNforSW3-2SO3-5,respectively),andtheductilityarealmostidentical.OneconcludethatcontributionofCFRPthebeamcapacitygreaterdegreeforbeamswithoutshearreinforcementforbeamswithshear-11FailureseriesSO3-12Appliedvs.forMeasuredverticalCFRPforspecimenSO3-4.3.4.SeriesSO4eriesSO4exhibitedinsheartoinvestigatedwiththisresearchTheexperimentalresultsintermsofvsdeflectioninhecontrolspecimenSO4-1asaresultofshearatatotalappliedloadofkN.SO4-2,strengthenedwithstrips,thefailurecontrolledCFRPdebondingatloadofkNwithincreasecapacitytheCFRPverticalatWhencomparingresultsofspecimenSO4-2tothatofSO3-2,-13capacity(a/d=4)dueadditionofwaskN,whilespecimenSO3-2(=3)inaddedshearof54kN.Asexpected,contributionCFRPreinforcementshearappearedtowithdecreasingstrengthenedwithcontinuousU-wrap,failedaresultofsplittinganappliedloadof310kNwitha138%increasecapacitycomparedtothatofSO4-1.Themaximumverticalstrainatfailurewasmm/mm.4.DesignapproachTheapproachtheshearcapacityofstrengthenedwithexternallybondedreinforcement,incode[12]format,in1998[13].describedtwofailureofCFRPreinforcementnamely:fracture;CFRPtwolimitsoncontributionofCFRPwereproposed.Thefirstlimitwasshearcrackwidthandofaggregateinterlock,andsecondtotheconcreteCFRPwrap-pingwereincorporatedasdesignparameters.Inrecent[9,10],modificationswere1998approachtoresultsofnewonCFRP[14].Inaddition,wastoprovidetheshearinEurocodewellACIComparingwithalltestresultsintheliterature76tests,designapproach[10,13].thesummaryofapproachispresented.Thecomparisonbetweenexperimentalcalculatedfactoredsheardemonstratestheabilityofapproachtocapacityofstrengthenedbeams.demonstratestheofapproachtopredicttheshearcapacityofstrengthenedbeams.-14Appliedloadvs.mid-spanforuseddefineareaofverticalorientedFRPand4.1.thesheardesignformatIntraditional(includingtheCode),thenominalshearofanRCsectionofnominalshearofshearreinforcement.beamsstrengthenedwithbondedFRPreinforcement,theshearmaybytheadditionoftoaccounttheFRPfollows:Theshear

V

,isobtainedmultiplyingthebyastrengthreductionforshear,ItthatthereductionfactorinACI[12]befortheandsteelterms.astringentreductionofforcontributionwasw10x.istherelativeofthistechnique.Thus,-15theisexpressed4.2.reinforcementtoshearcapacityTheexpressioncontributionofreinforcementisgiveninEq.ThissimilartothatcontributionofsteelconsistenttheACIformat.TheareaCFRPreinforcement,

A

f

,isthetotalthicknessofthet

f

oronofofCFRP

f

.ThedimensionsusedtheofCFRPinadditiontothespacing

s

f

thedepthofCFRP,f

，inFig.12.thatcontinuousverticalreinforcement,spacingthestrip,

s

f

,thewidthofstrip,

f

,InEq.anstress

f

,itsultimate

f

fu

,usedtothestressofsteel.Attheultimatelimitforinshear,itisnotpossibletoattainthefullofFRP[7,13].FailuregovernedbyeitherfractureofFRPsheetatstresswellbelowFRPultimatetoofFRPsheetfromconcretesurface,orainpost-crackingconcretestrengthalossofinterlock.Thus,stressisbyapplyingareductioncoefficient,R,theultimatein(4).Thereductionfailure(eitherCFRPordebonding).Inanupperlimitforthereductioncoefficientisinordertocontrolcracklossof-16LLLLinterlock.4.3.basedsheetfailureThereductioncoefficientcalibratedonallresultsto22testswithfailurecontrolledby，13].Thereductioncoefficientwasafunctionof

Ef

f

f

thefractionofinEq.(5)

Eff

0.7GPa.4.4.basedfailureThecapacitygovernedbyCFRPfromtheconcretewaspresented[9,10]asofCFRPconcretedepthofreinforcement,bondedconfigurations.Indeterminingreductioncoefficientforthebond,hastobefirst.BasedonandfromMiller[14]thatbondlengthslightlyincreases

tEf

f

,heconstantvalueeforThevaluemaybemodifiedwhenbondbecomesavailable.Afteracrackdevelops,onlyofofCFRPpastthebylengthisbecapableofcarrying

,basedontheshearangleof45°,thewrappingisinEqs.ifintheformaU-wrap(6a)ifisonlytosidesthebeam.(6b)ThefinalforreductionR,fortheoffailurebyin(8)(7)for

tf

f

,from20mm-GPa(kN/mm).Researchintobondcharacteristicsforabove-1790beingconductedtheofMissouri,(UMR).4.5.UpperlimitofreductioncoefficientInshearofaggregateinterlock,anlimitofcoefficient,wassuggestedcalibratedwithalloftheresults[10]beequalto

0.006/

fu

where

fu

theultimatetensilelimitissuchthataveragestraininCFRPatcannotbe0.006mm/mm(withoutthestrengtheningreductionfactor,).4.6.ControllingreductioncoefficientThefinalreductioncoefficientfortheCFRPtakenasthevaluefrommodesoffailureandtheNotethatifthetheorendmodeofCFRPdebondingisnottobeconsidered.reductioncoefficientisonlycontrolledbyFRPfracturethe4.7.spacingSimilartosteelreinforcement,andwithprovisionforthe[12],theFRPstripsshouldsowideastoallowtheadiagonalcrackwithoutastrip.Forifused,theynotbespacedbymaximuminEq.4.8.LimitontotalshearreinforcementACI318M-95[12]setalimitonthetotalthatbeprovidedthanofshearreinforcementprecludethewebreinforcementshouldbeinthislimit.AmodificationACI318M-95follows:4.9.CFRPstrengthenedTheproposedequationforthecontributionofmaybeinEurocode[15]-18Inthisequation,partialfactorforCFRPequalto1.3[10].Comparisonbetweenthetestandcalculated

f

,Thetestsummaryandthebetweentheresultsusingthedesignapproach(ACIformat),inTables23,CFRPstrengthenedbeams,thecontributionofVc,steelstirrups,Vs,(whenpresent)wereconsideredequaltoofanon-strengthenedbeam.Thenominalshearstrengthprovidedbyconcrete(11-5)inACI-318-95InEquationtheofVuandMparisonindicatesthattheapproachforstrengthenedbeamsillus-tratedin13.5.ConclusionsandfurtherrecommendationAninvestigationwastostudytheshearbehaviorandmodesofofsimplysupportedrectangularbeamswithstrengthenedwithCFRPsheets.parametersinvestigatedinthisprogramwereofshearreinforcement,shearspan-to-effectiveratioratio),andamountanddistribution.Theresultsconfirmthetechniquecanusedtoincreasesignificantlywithefficiencythatvariesonvariables.beamstestedinthisprogram,increasesinshearstrengthof40138%wereConclusionsthatemergedfrombesummarizedasfollows:●ThecontributionofCFRPreinforcementshearcapacityinfluencedbythe●IncreasingtheamountofCFRPmaynotinaproportionalincreaseinTheCFRPusedtostrengthenspecimenSO3-4-19ofthatinspecimenSO3-2,inaminimal(10%)incapacity.Anendanchorrecommendedifto●Thetestindicatedthatcontributionofthecapacityatforwithoutshearthanforwithshear●Theofseriesindicatedtheplyimprovedtheshearbyprovidinghorizontalrestraint.●TheshearprovidedforthestrengthenedRecommendationsresearchasfollows:-20●analyticalinvestigationsarerequiredlinktheshearcontributionofFRPwithloadcondition.studiesboththelongitudinalsteelreinforcementconcreteparameters.specimensmaintainpracticaldimensions.●ThestrengtheningeffectivenessofFRPhastobeintheofshortinwhichgovernsfailure.●Theinteractiontheofexternalshearreinforcementto●algorithms,specimensneedtobetestedwithdifferentCFRPamountadatabaseof●SheardesignalgorithmstobewithFRPandglassinadditionComparisonbetweenexperimentalcalculatedvaluesoffor6.NomenclatureA:spanA

f

ofCFRPff

w

:Widthofbeamcross-sectionD:Depthfromtopofthereinforcement-21:EffectivedepthoftheCFRPreinforcementequaltodforfrectangularforT-sections)modulusofFRP(GPa)ff

'c

:Nominalconcretecompressivef

tensilestressinFRPsheetintheofprincipalfibersinthefailure)f:UltimateofFRPsheetintheofprincipalfibersL:Effective(mm)R:coefficientofstressorstraininthesheettoitsultimateors:SpacingofFRPstripsftofFRPsheetononeofbeamf:Nominalstrengthbyconcretecfns

:NominalstrengthbyFRPreinforcement(ACIformat):Nominalstrengthformat):Nominalstrengthbysteelreinforcement(ACIformat):DesigncontributionofCFRPtoshearformat)

d2

:Designcapacityofconcrete(Eurocodeformat):Maximumthatcanbecarriedwithoutweb:Designofreinforcementformat)Wdw:WidthofFRPfofFRP(mm)fe-22

:Anglebetweenprincipalfibertheofbeamstrainoffu:tensileoftheintheFRPcomposite:reduction

ff

:Partialfactorforformat):FRPfyb)(wfysf)AcknowledgmentswaswithpartialsupportfromCenteronandNon-Destructive(NDT)TechnologiesbasedtheofMissouri,Rolla.CulturalEducationalWashington,providedtothefirstReferences[1]UjiK.ImprovingshearexistingreinforcedmembersfiberTransJpn1992;14:25366.[2]GJ,SharifA,IA,BN.repairreinforcedbonding.StructJ64.[3]JanuskaTF,MertzDR,TA,WW.Shearofbeamsappliedfabrics.ACI–303.[4]ArduiniDiFocacciF.ShearresponseofRCwithcarbonProceedingsThirdSymposiumonReinforcementforConcretevol.October–466.[5]L,Matthysbeamsstrengthenedinbysheets.ProceedingsoftheonNon-Metallic(FRP)ReinforcementforConcreteStructures,1.Japan,1997:483[6]SatoY,,Ultimateshearcapacityreinforcedconcretebeamswithcarbonfibersheets.ProceedingsofThirdon(FRP)ReinforcementforConcreteStructures,–506.-23[7]TriantafillouTC.Shearreinforcedusingepoxy-bondedcomposites.ACIStruct1998;95(2):10715.[8]NawyE.fundamentalapproach.Engle-woodCliffs,NewPrentice-Hill,(701p).[9]KhalifaTumialanG,NanniBelarbiA.ShearofexternallyCFRPsheets.InternationalonFiberReinforcedforStructures(FRPRCS-4).[10]Shearbeamsstrengthenedwithadvancedthesis.University,Egypt:Structural1999.[11]A,AlkhrdajiT,A,A.Anchorageofreinforcement.IntACI1999;49[12]ACICommittee318.Buildingrequirementsfor(ACI318–commentary(ACI318R-95).Concrete1995.pp).[13]W,A,Abdel-AzizMI.ContributionofbondedFRPtotheRCmembers.JComposConstr–202.[14]BrianD.,1999.betweencarbonsheetsMO,USA:DepartmentCivilTheUniversityofMissouri,[15]no.2,offorStandardization,-24abab中文译文：用碳纤维板(CFRP)修复剪切不足的矩形简支梁AhmedKhalifa

Nannia

埃及亚历山大市亚历山大大学结构工程部21544b

美国密苏里州密苏里州大学土木工程部年4月8号到初稿2001年10月30号收校稿年1月10号用。摘要目前研究调查剪切特性和破岩模式的矩形简支钢筋混凝土梁设计存在剪切不足。在实验室中这些构件经过外部的粘合剂碳纤维板加强和校核过。本实验方案由十二根合格的简支梁剪切破坏测试构成的验项目包括箍筋和剪跨比,以及数量和分布。试验结果显示外部粘合剂剪切承载力的贡献是重要的证明剪切承载力取决于变量研究实验结果用来证实一种保守并且可预测的剪切设计方法。（科学限公司版权所有）。关键字∶修复；剪切；碳纤维板（CFRP）1.引言纤维增强的聚合物(FRP合系统,是由纤维植入一种聚合物的基体组成的,能被用来加强受剪切的简支(RC）构[1现有的许多简支横梁存在抗剪切能力不足并需要加强一个简支横梁的剪切破坏明显地与它的弯曲破坏不同在剪切破坏时横梁没有充足的破坏征兆突然破坏并且斜向剪切裂缝比弯曲裂缝要宽很多[。本文的目的是∶研究剪切不足的简支矩形横梁在用外部粘合剂碳纤维板（CFRP）加固之后的性能和破坏模式。提出影响经过加固的横梁剪切承载力的因素如∶箍筋、剪跨比，和粘合剂碳纤维板（的数量和布置情况。增加用碳纤维板（CFRP）加固的钢筋混凝土梁的抗剪强度的实验数据。4.证实作者以前提出的一种设计方法[9]。基于上述目的12根合格的经过不同的C强方案的简支梁目的是测试梁抵抗剪切破坏的能力些构件是用两种不同剪跨比的简支梁施加四点荷载结-25构测试的。2.

实验方法2.1试件和仪器十二根跨距3050mm宽150mm，高305mm的矩形截面的合简支梁试件，试件被集合在两组依靠箍筋存在的名为W和的剪跨研究中。SW组由四根试件组成组试件的细部和尺寸当作对比这一组里，4四根直径32毫米的筋被用作纵向钢筋，从截面上看有根在顶端和在底部端面的被归纳到一种剪切破坏。这些试件是经过直径0mm的箍筋贯穿它们的全跨加固过的。箍筋间距在剪跨研究中,右半部分，用来允许整个跨距内破坏。SO组是由8根梁试件组成的，SW组有同的截面尺寸和纵向钢筋。在这次测试中半跨没有箍筋当做对比。。每个组（即：SW组和O组）再按照剪跨比分成二个部分。这就是剪跨比到4，形成下列四个小组∶SW3;SW4;SO3;和。加工这次测试试件的材料其力学性能都列在表上。加工试件的内容中关于表面处理和C置是在别处叙述的[。表材特性材料混凝土

说明组

抗压强度(MPa)

屈服点(MPa)

极限抗拉强度(MPa)

弹性模量SO组

钢筋CFRP

D＝32mmD＝10mmt＝

注：纤维唯一。2.2加强方案各组（SW3-1,SW4-1,SO3-1和SO4-1）都有一个试件没有加强用来作为检验用的基准试样是另外根梁试样是经过外部粘合剂CFRP板按照三不同的方案根据插图说明加强过的。在组，SW3-2组的试件是用2根垂直纤维方向的CFRP加强的。(900/00)第一个面用纤维连续不断的U型缠绕方式附属方向定位垂直于该试件的纵轴方向(。第二个面是沿梁轴线用纤维粘合的试件的两。这个面层[即00]，被作试验附加横向约束的冲击对抗剪强度的影响。在组中，试件W4-2和S用2根垂直方向的C固的(。-26组的四根梁试件是顺序加固的SO3-2试件是用一frp条采用垂直于纤维方向按照U型缠绕方式加固的。钢带宽度是5形心到形心间的间距为125mmSO3-3试件是以类似于试O3-2的方式加固的是钢带宽度为75mm。SO3-4试件是用一层连续不断的U型缠绕方式加固的（900。试件是用类似于试件SW3-2和W4-2的2根垂直方向的CFRP加固的(900/00)。单位：mm应传感器定位在箍筋上图梁样造和细部加固-27(a)一边板用CFRPU型缠绕（试件SO3-2,SO3-2和）(b)一边板用连续不断地U缠绕90（试件和）二边用型缠绕（试件SW3-2,SW4-2,）图2加方案的略图在组,二根梁试件是经过加固的。SO4-2试件是用类似于O3-2试件的一层U型缠绕方式的形式加固的。试件是用类似于O3-4的一层板连续不断的U型缠绕方式（90）加固的。2.3试验装备和测试设备全部的试件是作为简支梁承受四点荷载测试的，具体布置见图（）SW3和试（＝3）-28和件((b)SW3-2图试验装示意图一台功率的万能试验机用于施加一集中荷载并通过一个钢梁产生2集中荷载。荷载是循环渐进地施加的，通常在裂缝产生前是一个循环加一次荷载，在裂缝产生后是三个循环加一次，直到最后一次。作用载荷是竖直方向的。下图所示的挠度曲线就是这些荷载循环数的包络线。四个线性差动变压器(线性差动变压器)用于监测如图所示各个位置上的垂直位移二个线性差动变压器定位在试件的两个侧面跨中部分另外二个位于试件的支架上用来记录支架沉降值。对于SW组的每个试件，六个应变仪固定在三个箍筋上用来监测荷载作用下箍筋的应变情况，在图中有说明。三个应变仪直接固定到个面均经过FRP板加强的梁上用来监测的应变变化这些应变仪位于轴线方向上且在横截面中间高度，它们距离和支座处的距离分别为175、300425mm对于和的梁试件这些应变仪分别位于距离支架500和625mm的地方。3.

结果和论在下面的论述中,总是假定弱剪跨或跨距。3.1SW3组当荷载到达大90kN时观察检验用的基准试SW3-1接近于该剪跨中间部分的剪切。随着载荷的增大，附加剪切变形的裂缝形状贯穿整个梁，扩大并扩散直到加载到253kN时破坏见图）。SW3-2件用CFRP加固（），由于测试的试件被包裹起来了所以试件的侧面和底部没有裂缝可以看见。-29然而，在接近320这个高荷载时在梁的顶面有一道纵向的裂缝形成。裂缝在外部荷载施加的地方形成并向支座方向扩展延伸。试件在总荷载为时由于混凝土裂开而破坏（见图）。（）试件（b试图组件的破坏形式这比检验用的基准试样SW3-1极限承载力增加了40%该裂缝之所以会破坏是由于试件顶部有较高的纵向压应力在发展起一个横向张力致裂缝而破坏。另外，相对大量的纵向钢筋与CFRP结合，过度加强抗剪能力可能导致了这种破坏形式。图5说明了SW3-1和SW3-2件中荷载与中跨挠度曲线的关-30系，以表明通过使用高了承载力。测量到的大垂直应变位于SW3-2试件，大约是0.0023mm/mm相当于CFRP限应变的。就一裂缝而言这个数值不是独立存在的因为它极大地取决于应变仪的定位然而应变记录显示如果裂缝没有发生，抗剪承载力还可以到达一个更高的数值。图组件外加荷载与跨中挠度关系表SW3-1和SW3-2试件之间箍筋应变的比较在图中有显示。箍筋1,2和3分别位于位于距离支座300地方。试验结果显示两个试件2号和3箍筋最后都没有屈服由于作用试件箍筋的应（和应力）通常小于同等荷载情况下试件SW3-1的。3.2SW4组在SW4-1试件中，在外部施加的总荷载为时构件上形成了第一道斜裂缝随着载荷的增长附加剪切变形裂缝似乎要贯穿整个剪跨当外施荷载总数到达200kN横梁发生破坏在a/d＝3的情况下这比试件的抗剪能力少了。SW4-2试件类似于试件，其破坏是受混凝土的劈裂约束的。-31图和SW3-2试件箍筋外部荷载应变关系图抗剪承载力比检验用的基准试样SW4-1增加了，最终的外施荷载达到了而且，试箍筋的实测应变小于试件SW4-1的梁SW4-1和SW4-2外施荷载与跨中挠度曲线的关系见图7。与试件SW4-1相比我们注意到试件SW4-2产生了更大的挠度。图组件外施荷载与跨中挠度关系当比较W3和试件的测试结果时，我们看到SW3-2件和SW4-2试件的最终破坏载荷是差不多的。然而，由于经过CFRP加固，SW3-2a/d＝3）试件的承载力提高101kN(a/d=4)试件的承载力提高了kN。-32这表明额外增加的的贡献可能受a/d的影响，并且似乎随着a/d比的减小而减少。另外，对两个加固过的试W3-2和来说，最CFRP板没有断裂或与混凝土失去粘结表明如果横梁没有劈裂破CFRP以提供附加强度。3.3SO3组图8明试件的破坏模式。图9为试件外施荷载与跨中挠度的细部图。图SO3组件破坏模式-33图组件外施荷载与跨中挠度关系检验用的基准试样SO3-1失效模型是剪切压坏。试件在外施荷载总值为时发生破坏。与SW3-1试件相比，由于缺乏箍筋，导致抗剪承载力减少了54.5kN。而且，试的裂缝分布况与试件的也不同。在试件SW3-1中，由于箍筋的存在提供了一个更好的斜裂缝使之贯穿剪跨。试件是用间距直径CFRP带加固的，在外施荷载为时可以观察到第一个斜剪切裂缝。试件的裂缝扩展随着载荷增长以类似方式增大由于CFRP条在斜线剪切裂缝上方失去粘结附着于条的混凝土剥落，所以导致失效突然发生。最终极限负载是kN，比检验用的基准试样SO3-1的抗剪承载力提高了。试件SO3-2坏时测量到最大的CFRP垂直应变是（即28%的极限应变），这表明CFRP并没有达到它的极限应变。用直径CFRP条加固的SO3-3试件在外施荷载为266kN时由于CFRP与混凝土剥离而破坏。竖直方向记录到最大的破坏应变为（即极限应变）。用CFRP以连续不断的U型缠绕方式加固的SO3-4试件（），在外施荷-34载为289kN由于与混凝土剥离而破坏。结果表明试件分别比试件SO3-1、SO3-2和SO3-3的抗剪承载力增大了87108.5%。SO3-4试件中外施荷载与直应关系见图。图试件中测量到的垂直应变其中应变仪sg1，sg2和别位于距离支架、和的截面形心处。10表明，在斜裂缝成之前CFRP应变为零，然后慢慢地增加直到检验用的基准试样的荷载接近它的极限强度。就在这一点，CFRP的应变显著地增加直到破坏。破坏时测量到CFRP最大的垂直应变大约是。当我们比较和横梁的结果时加强SO3-4试件的CFRP消耗量是SO3-2试件所用的250%。多使用的CFRP只提高了10%的抗剪承载力这意味是不是存在一个控FRP发生剥离的限值在一个最合适的FRP、如果超过该量则加强效果是不确定的。上述的研究结果[表明通过使用一端锚定系统FRP混凝土剥离的失效模型是可以避免的基于对文献中试验结果有效范围的评估我们认为报告结果和其他研究是一致的[7]并且表明FRP对抗剪承载力的影响几乎是线性的，用

f

E

f

（

f

是FRP面积百分率，Ef是FRP的弹性模数）表示的轴向刚度大约是除了这些意义外，FRP的有效作用便不再那么显著。-35000000在试件中，通过在连续不断U型缠绕方式上使用一横向板层（即90/0导致了混凝土劈裂破坏而不是CFRP与混凝土剥离破坏与该检验用的基准试样SO3-1相比，其抗剪承载力提高了120%，破坏发生时外施荷载为。与只900方向（即试SO3-4用一CFRP板加固相比，用二个垂直的（即90/0）就提高了的抗剪承载力。破坏时测到CFRP最大的垂直应变是。通过比较有相同的剪跨比和加固方案但是不同抗剪钢筋量的SW3-2和试件结果看到它们的抗剪强SW3-2试件的177kN和SO3-5试件的），以及延性是差不多的。一个可能的结论就是对没有抗剪钢筋梁承载力提高的影响比满足抗剪钢筋要求的横梁更大。3.4.组组与其它被调查的试验比较表现出了最大增量的剪力组试验中施加荷载与跨中挠度关系见图。施加的荷载达到1时，试O4-1产生剪压破坏。FRP条来加强试件SO4-2，施加的荷载