中文2630字ANEXPERIMENTALSTUDYONFLEXURALBEHAVIOROFRCBEAMSSTRENGTHENEDWITHNSMREINFORCEMENTWoo-TaiJUNG1,Young-HwanPARK2,Jong-SupABSTRACT:ThisstudypresentstheresultsofexperimentsperformedonRC(ReinforcedConcrete)beamsstrengthenedwithNSM(NearSurfaceMounted)reinforcement.Atotalof6specimenshavebeentested.ThespecimenscanbeclassifiedintoEBR(ExternallyBondedReinforcement)specimenandNSMreinforcementsspecimens.TwoNSMspecimenswithspacevariableswerestrengthenedwith2CFRP(CarbonFiberReinforcedPolymer)strips.ExperimentalresultsrevealedthatNSMspecimensusedCFRPreinforcementsmoreefficientlythantheEBRspecimens.EvenifCFRPcrosssectionareasofNSMspecimenshave30%,50%ofEBRSpecimen,thestrengtheningeffectofNSMspecimensissuperiortoEBRspecimen.NSMspecimenswithspacevariablesshowedthatthstrengtheningeffectofthespecimenwithnarrowspaceisslightlyincreasedascomparedtothespecimenwithwidespaceuKEYWORDS:carbonfiberreinforcedpolymer,externallybondedCFRPreinforcements,nearsurfacemountedCFRPreinforcements,strengthening1.INTRODUCTIONAmongthevariousstrengtheningtechniquesthathavebeendevelopedandappliedtostrengthendeterioratedRCstructures,anumberofapplicationsusingFRPreinforcementshavesignificantlyincreasedrecently.FRPreinforcementsarebondedtoconcretesurfacesbyadhesivesbutfrequentlyexperiencedebondingfailureattheinterfacebetweenFRPreinforcementsandconcrete.Mostresearch,todate,hasfocusedoninvestigatingthestrengtheningeffectsandfailuremodesofEBRsystemTheproblemofprematurefailureofEBRsystemmaybesolvedbyincreasingtheinterfacebetweenFRPandconcrete.Usingthisprinciple,theNSMsystemhasbeenintroducedrecently.TheNSMsystemforconcretestructureusingsteelreinforcementalreadybeganin1940s.However,thecorrosionofthesteelreinforcementandthepoorbondingperformanceofthegroutingmateriallargelyimpaireditsapplication.ThedevelopmentofimprovedepoxyandtheadoptionofFRPreinforcementofferedtheopportunitytoimplementNSMsystem(HassanandRizkalla2003;ljstenTäandCarolin2001).Becauseoftheirlightweight,easeofinstallation,m