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【英文标准名称】:StandardTestMethodforPulseVelocityThroughConcrete
【原文标准名称】:通过混凝土脉冲速度的标准试验方法
【标准号】:ASTMC597-2009
【标准状态】:现行
【国别】:美国
【发布日期】:2009
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:C09.64
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:concrete;longitudinalstresswave;nondestructivetesting;pulsevelocity;ultrasonictesting;Nondestructiveevaluation(NDE)--concrete/masonry;Pulsevelocity
【摘要】:Thepulsevelocity,V,oflongitudinalstresswavesinaconcretemassisrelatedtoitselasticpropertiesanddensityaccordingtothefollowingrelationship:Thistestmethodisapplicabletoassesstheuniformityandrelativequalityofconcrete,toindicatethepresenceofvoidsandcracks,andtoevaluatetheeffectivenessofcrackrepairs.Itisalsoapplicabletoindicatechangesinthepropertiesofconcrete,andinthesurveyofstructures,toestimatetheseverityofdeteriorationorcracking.Whenusedtomonitorchangesinconditionovertime,testlocationsaretobemarkedonthestructuretoensurethattestsarerepeatedatthesamepositions.Thedegreeofsaturationoftheconcreteaffectsthepulsevelocity,andthisfactormustbeconsideredwhenevaluatingtestresults(Note1).Inaddition,thepulsevelocityinsaturatedconcreteislesssensitivetochangesinitsrelativequality.Note18212;Thepulsevelocityinsaturatedconcretemaybeupto5%higherthanindryconcrete.Thepulsevelocityisindependentofthedimensionsofthetestobjectprovidedreflectedwavesfromboundariesdonotcomplicatethedeterminationofthearrivaltimeofthedirectlytransmittedpulse.Theleastdimensionofthetestobjectmustexceedthewavelengthoftheultrasonicvibrations(Note2).Note28212;Thewavelengthofthevibrationsequalsthepulsevelocitydividedbythefrequencyofvibrations.Forexample,forafrequencyof54kHzandapulsevelocityof3500m/s,thewavelengthis3500/54000=0.065m.Theaccuracyofthemeasurementdependsupontheabilityoftheoperatortodeterminepreciselythedistancebetweenthetransducersandoftheequipmenttomeasurepreciselythepulsetransittime.Thereceivedsignalstrengthandmeasuredtransittimeareaffectedbythecouplingofthetransducerstotheconcretesurfaces.Sufficientcouplingagentandpressuremustbeappliedtothetransducerstoensurestabletransittimes.Thestrengthofthereceivedsignalisalsoaffectedbythetravelpathlengthandbythepresenceanddegreeofcrackingordeteriorationintheconcretetested.Note38212;Propercouplingcanbeverifiedbyviewingtheshapeandmagnitudeofthereceivedwaveform.Thewaveformshouldhaveadecayingsinusoidalshape.Theshapecanbeviewedbymeansofoutputstoanoscilloscopeordigitizeddisplayinherentinthedevice.Theresultsobtainedbytheuseofthistestmethodarenottobeconsideredasameansofmeasuringstrengthnorasanadequatetestforestablishingcomplianceofthemodulusofelasticityoffieldconcretewiththatassumedinthedesign.ThelongitudinalresonancemethodinTestMethodC215isrecommendedfordeterminingthedynamicmodulusofelasticityoftestspecimensobtainedfromfieldconcretebecausePoisson''sratiodoesnothavetobeknown.Note48212;Whencircumstancespermit,avelocity-strength(orvelocity-modulus)relationshipmaybeestablishedbythedeterminationofpulsevelocityandcompressivestrength(ormodulusofelasticity)onanumberofsamplesofaconcrete.Thisrelationshipmayserveasabasisfortheestimationofstrength(ormodulusofelasticity)byfurtherpulse-velocitytestsonthatconcrete.RefertoACI228.1Rforguidanceontheproceduresfordevelopingandusingsucharelationship.Theprocedureisapplicableinbothfieldandlaboratorytestingregardlessofsizeorshapeofthespecimenwithinthelimitationsofavailab..........
【中国标准分类号】:Q13
【国际标准分类号】:91_100_30
【页数】:4P.;A4
【正文语种】:英语