簡介:JOURNALOFWUHANUNIVERSITYOFTECHNOLOGYMATERSCIEDDEC2008917DOI101007/S115950076917XHEALINGEFFECTIVENESSOFCRACKSREHABILITATIONINREINFORCEDCONCRETEUSINGELECTRODEPOSITIONMETHODJIANGZHENGWU1,XINGFENG2,SUNZHENPING1,WANGPEIMING11KEYLABORATORYOFADVANCEDCIVILENGINEERINGMATERIALSOFMINISTRYOFEDUCATION,TONGJIUNIVERSITY,SHANGHAI200092,CHINA2SHENZHENKEYLABORATORYOFCIVILENGINEERINGDURABILITY,SHENZHENUNIVERSITY,SHENZHEN518060,CHINA)ABSTRACTANELECTRODEPOSITIONMETHODANDITSEXPERIMENTALDEVICEFORREHABILITATIONOFCRACKSINREINFORCEDCONCRETEWEREPROPOSEDPOROUSCONCRETEISPROPOSEDTOSIMULATECRACKEDCONCRETE,ANDMASSINCREMENT,PERMEATIONCOEFFICIENTANDSOUNDVELOCITYOFULTRASONICWAVEWEREUSEDTOBEEVALUATINGINDICATORSOFHEALINGEFFECTIVENESSOFCRACKREHABILITATIONINTHISMETHODEFFECTOFCURRENCYDENSITY,CONCENTRATIONOFELECTROLYTESOLUTIONONHEALINGEFFECTIVENESSOFPOROUSREINFORCEDCONCRETESWITHDIFFERENTTOTALVOIDRATIOWASSTUDIEDTHEEXPERIMENTALRESULTSINDICATETHATTHESIMULATIONOFPOROUSCONCRETEFORCRACKSCANREFLECTTHEHEALINGEFFECTIVENESSOFELECTRODEPOSITIONMETHODEFFECTIVELYTOTALVOIDRATIOOFPOROUSCONCRETEHASLITTLEEFFECTONHEALINGEFFECTIVENESSOFELECTRODEPOSITIONATEARLYAGESTHEHIGHERTHECURRENCYDENSITYORCONCENTRATIONOFELECTROLYTESOLUTIONIS,THEHIGHERTHEELECTRODEPOSITIONRATEANDSOUNDVELOCITYINPOROUSCONCRETEARE,ANDTHELOWERTHEPERMEATIONCOEFFICIENTOFPOROUSCONCRETEWILLBEMGOH2CRYSTALSPRODUCEDINHIGHCURRENTDENSITYARELARGE,THINSHEETSHAPEDANDARRANGEDLOOSELYKEYWORDSELECTRODEPOSITIONPOROUSREINFORCEDCONCRETECRACKHEALING1INTRODUCTIONREINFORCEDCONCRETERCISAKINDOFWIDELYUSEDCONSTRUCTIONMATERIALFORBUILDINGS,BRIDGES,HYDRAULICCONSTRUCTIONSANDMARINEPROJECTS,ETCHOWEVER,RCSTRUCTUREWILLUSUALLYGENERATEMICROCRACKSINEVITABLYINTHEIRSERVICELIFEUNDERSURROUNDINGENVIRONMENTEROSION,WHICHREDUCESLOADBEARINGANDDURABILITYOFRCSTRUCTURESGREATLY1SO,ITISNECESSARYTOREHABILITATEORREPAIRTHEMACCORDINGTOREASONSINDUCINGCRACKSANDTHEIRENVIRONMENTCONDITIONS,MANYREPAIRMETHODSSUCHASREINFORCEMENT,ANCHORING,GROUTING,SEALINGANDREPLACEMENTETCAREPROPOSED26HOWEVER,THESEMETHODSSHOWCERTAINLIMITATIONSFORCRACKSINRCSTRUCTURESUNDERWATERENVIRONMENTITISOFGREATPRACTICALSIGNIFICANCETODEVELOPNEWNONDESTRUCTIVEREHABILITATIONMETHODSFORUNDERWATERCONCRETESTRUCTURESELECTRODEPOSITIONMETHODISONEOFNEWDEVELOPEDMETHODSFORREHABILITATIONOFCRACKSINUNDERWATERRC710ITTAKESADVANTAGEOFTHECHARACTEROFRCANDWATERENVIRONMENTCONDITION,PUTSAWEAKDIRECTCURRENTBETWEENREBARINRCSTRUCTURESANDANEXTERNALELECTRODEANANODEANDPRODUCESELECTRODEPOSITSAROUNDREBARINRC,WHICHWILLFORMABARRIERCOATINGOFINORGANICINSOLUBLECOMPOUNDSSUCHASZNO,CACO3ANDMGOH2,ETCINCRACKSANDSURFACES,FILLCRACKSANDSEALSURFACESOFRCINRECENTYEARS,SEVERALSTUDIES7,1014AREREPORTEDONTHETOPICABOUTITSFEASIBILITY,MECHANISMANDEXPERIMENTALCONTROLOFREHABILITATIONOFCRACKSINRCUSINGELECTRODEPOSITIONMETHODHOWTOSIMULATECRACKSINRCINTHELABORATORY,PRESETCRACKSINCONCRETESPECIMENSANDEVALUATEHEALINGEFFECTIVENESSOFCRACKSINRCEFFECTIVELYAREHOTANDDIFFICULTRESEARCHTOPICSOFREHABILITATIONOFCRACKSINRCUSINGELECTRODEPOSITIONMETHODCURRENTLY,THETWOMAINSIMULATINGMETHODSINCLUDINGSPLITTINGANDCRACKINGBYSALTCORROSIONAREPROPOSEDFORPRESETTINGCRACKSINRC7,10,14,WHICHHASSEVERALSHORTCOMINGSSUCHASCRACKRANDOMNESS,OUTOFCONTROLLINGOFWIDTHANDORIENTATIONOFCRACKS,ANDDIFFICULTYINEVALUATINGHEALINGEFFECTIVENESSOFCRACKSUSINGELECTRODEPOSITIONMETHODTHEREFORE,INORDERTOEVALUATEHEALINGEFFECTIVENESSOFCRACKSREHABILITATIONINRCUSINGELECTRODEPOSITIONMETHODEFFECTIVELY,POROUSCONCRETEWITHDIFFERENTTOTALVOIDRATIORECEIVEDSEP12,2007ACCEPTEDMAR9,2008JIANGZHENGWU蔣蔣蔣ASSOCPROFPHDEMAILJZHWTONGJIEDUCNFUNDEDBYTHENATIONALNATURALSCIENCEFOUNDATIONOFCHINA50508029,SHANGHAIPROVINCIALNATURALSCIENCEFOUNDATION05ZR14121ANDOPENFUNDOFSHENZHENKEYLABORATORYOFCIVILENGINEERINGDURABILITYOFSHENZHENUNIVERSITYCED0601萬方數(shù)據(jù)JOURNALOFWUHANUNIVERSITYOFTECHNOLOGYMATERSCIEDDEC200891924TESTINGMETHODSTHEAPPARENTDENSITYOFPOROUSCONCRETEWASMEASUREDBYAVOLUMETESTINGMETHODTHEPOROUSSPECIMENSWITHTHEDIMENSIONSOF100MM100MM100MMWEREKEPTINDRYAIRFOR5HAFTERBEINGTAKENOUTOFTHECURINGROOM,WHICHMADETHEMREACHSATURATEDSURFACE–DRYCONDITIONSTHENTHEIRMASSANDDIMENSIONSWERETESTEDTHEMEASUREMENTACCURACYOFTHEDIGITALWEIGHTINGSCALEREACHED±1GANDTHEDIMENSIONMEASUREMENTACCURACYOFTHEVERNIERCALIPERREACHED±01MMACCORDINGTOTHEMASSANDVOLUMEOFSPECIMENS,THEAPPARENTDENSITYOFPOROUSCONCRETEWASCALCULATEDOUTTHREESPECIMENSWEREMEASUREDINEACHGROUPANDTHEIRAVERAGEWASCONSIDEREDASTHEAPPARENTDENSITYOFPOROUSCONCRETEPOROUSRCSPECIMENSWITHTHEDIMENSIONSOF100MM100MM200MMWEREUSEDTOMEASURETHEMASSINCREMENTOFPOROUSRCSPECIMENAFTERELECTRODEPOSITIONTHEMASSOFPOROUSRCSPECIMENSWASMEASUREDAFTERGIVENHEALINGAGESMEASUREMENTMETHODOFMASSINCREMENTOFPOROUSRCSPECIMENSWASSIMILARTOTHEMEASUREMENTOFAPPARENTDENSITYOFPOROUSCONCRETETVRWASOBTAINEDBYDIVIDINGTHEDIFFERENCEBETWEENTHEWEIGHTM1OFTHESPECIMENSINTHEWATERANDTHATM2MEASUREDFOLLOWINGAIRDRYINGFOR24HBYTHESPECIMENVOLUMETHEWEIGHTOFSPECIMENSWASMEASUREDBYAPOINTERTENSIONDYNAMOMETERANDITSACCURACYREACHES1GSIZESOFSPECIMENSWEREMEASUREDBYAVERNIERCALIPERANDITSMEASUREMENTACCURACYOFSIZEREACHED1MMTHEEQUATIONUSEDTOOBTAINTHETVRISASFOLLOWS1WHERE,AISTHETVROFPOROUSCONCRETE,M1THEUNDERWATERWEIGHTOFSPECIMEN,GM2THEWEIGHTOFSPECIMENDRIEDINAIRFOR24H,GV1THESPECIMENVOLUME,CM3ΡWTHEDENSITYOFWATER,KG/MM3COMPRESSIVESTRENGTHOFPOROUSCONCRETESPECIMENSWASMEASUREDAT7DAYSAND28DAYSINACCORDANCEWITHCHINESETESTSTANDARDGBJ8185THEREISNOSTANDARDMETHODSANDDEVICEFORPERMEATIONCOEFFICIENTMEASUREMENTOFPOROUSCONCRETEINTHEDOMESTICTHEWATERPERMEABILITYTESTINGMETHODFORORDINARYCONCRETEISNOTSUITABLEFORPOROUSCONCRETESO,ANEWTESTINGDEVICEFORPERMEATIONCOEFFICIENTOFPOROUSCONCRETEWASDESIGNEDINTHISEXPERIMENTTHESPECIFICMEASUREMENTDETAILANDCALCULATIONMETHODOFPERMEATIONCOEFFICIENTOFPOROUSCONCRETEWASDESCRIBEDINTHEREF15ULTRASONICWAVEMETHODWASUSEDTOMEASURETHESOUNDVELOCITYOFPOROUSRCSPECIMENBEFOREELECTRODEPOSITIONANDAFTER28DAYSELECTRODEPOSITIONTOEVALUATEHEALINGEFFECTIVENESSOFCRACKSTHESOUNDVELOCITYOFTHREECOUPLESOFPARALLELSPECIMENSURFACESWASTESTEDINORDERTOAVOIDTHEEXPERIMENTALERRORINDUCEDBYREBARINSPECIMENS,THETESTINGPOINTOFULTRASONICPROBEWASLOCATEDINTHEMIDDLEOFEVERYCOUPLEOFPARALLELSURFACESSHOWNINFIG3ACCORDINGTOTHELOCATIONOFREINFORCEMENTCAGEINSPECIMENS,REBARHADNOEFFECTONTESTINGRESULTSMOREOVER,INORDERTOAVOIDTHEINFLUENCEOFMOISTURECONTENTINSPECIMENONTESTINGRESULTS,THESPECIMENSWEREDRIEDINATEMPERATUREOF105±3℃BEFORETESTED3RESULTSANDDISCUSSION31PROPERTIESOFPOROUSCONCRETEWITHDIFFERENTMIXPROPORTIONSASSHOWNINTABLE1,THEPOROSITIESOFPOROUSCONCRETESUCHASAPPARENTDENSITYANDCOMPRESSIVESTRENGTHARERELATEDWITHTVROFPOROUSSPECIMENSTIGHTLYTHEHIGHERTHETVROFPOROUSSPECIMENS,THESMALLERTHEAPPARENTDENSITYOFTHEMISDUETODIFFERENTGRADUATIONCOMPOSITIONOFAGGREGATE,THREESERIESOFPOROUSSPECIMENSHAVEDIFFERENTTVR,WHICHAFFECTSHEALINGEFFECTIVENESSOFREHABILITATIONDIFFERENTLYP2HASTHEHIGHESTTVROF30,P1ISTHELOWESTTVROF133,ANDTVROFP3REACHES20732EFFECTOFDIFFERENTFACTORSONTHEMASSINCREMENTOFPOROUSSPECIMENSAFTERELECTRODEPOSITION321TVRFIG4SHOWSTHEUNITVOLUMEMASSINCREMENTOFSPECIMENSASAFUNCTIONOFHEALINGTIMEWHENCURRENTDENSITYOF05A/M2ANDMGNO32CONCENTRATIONOF005MOL/LISGIVENASITSHOWS,THEUNITVOLUMEMASSINCREMENTOFALLSPECIMENSINCREASESOBVIOUSLYAFTERELECTRODEPOSITIONANDITINCREASESWITHTHEINCREASEOFHEALINGTIMEITVERIFIESTHATELECTRODEPOSITIONISEXISTEDINTHEMACROSCOPICSCALEANDTHEELECTRODEPOSITSAREPRECIPITATEDINTHEPOROUSSPECIMENSTHEMASSINCREMENTOFEACHSERIESISSIMILARINTHEFIRST7DAYSOFHEALINGTHEMASSINCREMENTOFP2ISHIGHERTHANTHOSEOFP1ANDP3AT60DAYSITINDICATESTHATTVRHASLITTLEEFFECTONELECTRODEPOSITIONPROCESSANDPRECIPITATIONATEARLYHEALINGAGES,ANDTHEMASSINCREMENTINCREASESWITHTHEINCREASEOFTVROFPOROUSSPECIMENSATLATERHEALINGAGESITLIESINTHATSPECIMENSWITHLOWTVRAREBLOCKEDBYELECTRODEPOSITSGRADUALLY,ANDSOTHEELECTRODEPOSITIONRATEDECREASES100/1112????????VMMAWΡFIG3THETESTINGPOINTLOCATIONOFULTRASONICWAVEMETHODINSPECIMEN萬方數(shù)據(jù)
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