简介：Thecapabilityofembeddedpiezoelectricwaferactivesensors(PWAS)toperformin-situnondestructiveevaluation(NDE)forstructuralhealthmonitoring(SHM)ofreinforcedconcrete(RC)structuresstrengthenedwithfiberreinforcedpolymer(FRP)compositeoverlaysisexplored.First,thedisbonddetectionmethodweredevelopedoncouponspecimensconsistingofconcreteblockscoveredwithanFRPcompositelayer.Itwasfoundthattheprescnceofadisbondcrackdrasticallychangestheelectromecbanical(E/M)impedancespectrummeasuredatthePWASterminals.ThespectralchangesdependonthedistancebetweenthePWASandthecracktip.Second,largescaleexperimentswereconductedonaRCbeamstrengthenedwithcarbonfiberreinforcedpolymer(CFRP)compositeoverlay.Thebeamwassubjecttoanacccleratcdfatigueloadregimeinathree-pointbendingconfigurationuptoatotalof807,415cycles.Duringthesefatiguetests,theCFRPoverlayexperienceddisbondingbeginningatabout500,000cycles.ThePWASwereabletodetectthedisbondingbeforeitcouldbereliablyseenbyvisualinspection.GoodcorrelationbetweenthePWASreadingsandthepositionandextentofdisbonddamagewasobserved.ThesepreliminaryresultsdemonstratethepotentialofPWAStechnologyforSHMofRCstructuresstrengthenedwithFRPcompositeovcrlays.