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MaterialsScienceandEngineeringA 479 (2008) 191–196CFRC增强的RC梁在疲劳和单调荷载作用下的力学行为和电学性能MechanicalbehaviorandelectricalpropertyofCFRC-strengthenedRCbeamsunderfatigueandmonotonicloadingWeiWanga,∗,HongzheDaia,SigangWubbSchoolofCivilEngineering,HarbinInstituteofTechnology,HaiheRoad202,Harbin,150090,ChinaSchoolofScienceandEngineeringonCommunications,HarbinInstituteofTechnology,HaiheRoad202,Harbin150090,ChinaReceived29August2006;receivedinrevisedform13June2007;accepted18June2007aAbstractThisstudyintroducesanewCFRC-strengthenedRCbeammodelwhichcanbothstrengtherimentoftestingfour-pointbendingbeamsisproceededinordertoanalyzemechanicalbehaviorandelectricalpropertyofthedesignedbeamundermonotonicloadingaswellastherelationshipbetweenelectricalpropertyandfatiguedamageundercyclicfllyticalresultsindicatethatthisinnovativeCFRC-strengthenedbeamhasbetterflexuralperfs,thechangundthatthethickertheCFRClayer,thelargertheelectricalresistanceincreases,andwhileelectricalresistanceirreversiblyincreasesasloadcyclingprogresses,thegreaterthestressamplitude,thegreaterthefatiguedamage,nthisdiscovery,anewtechniquetomonitorthedamageofthedesignedCFRC-strengthenedRCbeamisproducedbymeansofresistancemeasurement.© 2007 Elsevier B.V. All rights ds:CFRClayer;Strengthening;Mechanicalbehavior;Conductivenetwork;uctionForrecentyears,theconcreteconstructionindustryhasbeenfacingaverysignificantchallengeinviewofthedeteriorationofinfrastructures,andthishasmotivatedresearonally,concreteelementsworkwithvarioustypesofcracksinmostcases,butforsomeinfrastructuressuchasdams,highwaysandnuclearplants,actiquenowgainingpopular-ityisthebondingofcarbonfiber-reinforcedpolymer(CFRP)usedextensivelytostrengthenreinforcedconcrete(RC)beamsorcolumnsnotonlyforitsgoodmechanicalperformancesuchashighflexuralstrengthandtoughnessbutforitsattractiveelectricalproperty[1–8].UsingCFRPlaminateshasprovedtobeaneffectivemeansofupgradingandstrengtheningRCbeams,andanamountofresearchhasbeendonetoevaluatetheflexuralperformance∗.:+8645186282075;fax:+8645186282704.E-mailaddress:wwang@().ofRCbeamsretrofittedwithCFRP[9–12].However,prema-turefailuressuchaspeelingfailureandlaminateseparationcansignificantlylimitthecapacityenhancementandpreventthefullultimateflexuralcapacityoftheretrofitepeelingorseparationmayoccurduetothehighlongitudinalshearandtransversenormalstressesattheplateendresultingfromtheabruptcurtailmentoftheplate[13,14].Moreover,althoughmajorapplicationsofCFRParereportedintheliterature,designengineersares,asatypeoffunctionalmaterial,CFRPitselftentionhasbeenpaidinrecentyearstoCFRP’selectri-calproperty[5–8].However,mostresearchhascontributedinanalyzingthecarbonfiberreinforcedmortar(CFRM),particu-larlyinself-monitoringofdamageintestspecimenwhichcouldbeonlyconfige-scalestructuralelementwhichismadeofcarbonfiberreinforcedcon-crete(CFRC)hasnotbeenpaidmuchattention,tediffersfrommortarasconcretecontainscoarseaggregate,itionofcoarseaggregateincreasesboththeheterogeneityofCFRMandthe0921-5093/$–seefrontmatter© 2007 Elsevier B.V. All rights :10.1016/.2007.06.046192Table1ThepropertiesofcarbonfiberItemTargetDiameter(␮m)al./MaterialsScienceandEngineeringA 479 (2008) 191–196Tensilestrength(GPa)4.0Tensilemodulus(GPa)240Resistance(