【英文标准名称】:StandardTestMethodforCreepofConcreteinCompression
【原文标准名称】:压缩过程中混凝土蠕变的标准试验方法
【标准号】:ASTMC512-2002
【标准状态】:现行
【国别】:
【发布日期】:2002
【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】:C09.61
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:混凝土;压力;施工材料;试验
【英文主题词】:compression;concrete;creep;creepstrain;elasticstrain
【摘要】:Thistestmethodmeasurestheload-inducedtime-dependentcompressivestrainatselectedagesforconcreteunderanarbitrarysetofcontrolledenvironmentalconditions.Thistestmethodcanbeusedtocomparecreeppotentialsofdifferentconcretes.Aprocedureisavailable,usingthedevelopedequation(orgraphicalplot),forcalculatingstressfromstraindatawithinmassivenon-reinforcedconcretestructures.Formostspecificdesignapplications,thetestconditionssetforthhereinmustbemodifiedtomorecloselysimulatetheanticipatedcuring,thermal,exposure,andloadingageconditionsfortheprototypestructure.CurrenttheoriesandeffectsofmaterialandenvironmentalparametersarepresentedinACISP-9,SymposiumonCreepofConcrete.3Intheabsenceofasatisfactoryhypothesisgoverningcreepphenomena,anumberofassumptionshavebeendevelopedthathavebeengenerallysubstantiatedbytestandexperience.3.3.1Creepisproportionaltostressfrom0to40%ofconcretecompressivestrength.3.3.2Creephasbeenconclusivelyshowntobedirectlyproportionaltopastecontentthroughouttherangeofpastecontentsnormallyusedinconcrete.Thus,thecreepcharacteristicsofconcretemixturescontainingaggregateofmaximumsizegreaterthan2in.(50mm)maybedeterminedfromthecreepcharacteristicsoftheminus2-in.(minus50-mm)fractionobtainedbywet-sieving.Multiplythevalueofthecharacteristicbytheratioofthecementpastecontent(proportionbyvolume)inthefullconcretemixturetothepastecontentofthesievedsample.Theuseofthelogarithmicexpression(Section8)doesnotimplythatthecreepstrain-timerelationshipisnecessarilyanexactlogarithmicfunction;however,fortheperiodofoneyear,theexpressionapproximatesnormalcreepbehaviorwithsufficientaccuracytomakepossiblethecalculationofparametersthatareusefulforthepurposeofcomparingconcretes.Therearenodatathatwouldsupporttheextrapolationoftheresultsofthistesttotensionortorsion.1.1Thistestmethodcoversthedeterminationofthecreepofmoldedconcretecylinderssubjectedtosustainedlongitudinalcompressiveload.Thistestmethodislimitedtoconcreteinwhichthemaximumaggregatesizedoesnotexceed2in.(50mm).1.2Thevaluesstatedininch-poundunitsaretoberegardedasthestandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【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】: