ASTM-C157-2008-Standard-Test-Method-for-Length-Cha

Designation:C157/C157M–08StandardTestMethodforLengthChangeofHardenedHydraulic-CementMortarandConcrete1ThisstandardisissuedunderthefixeddesignationC157/C157M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheDepartmentofDefense.1.Scope*1.1Thistestmethodcoversthedeterminationofthelengthchangesthatareproducedbycausesotherthanexternallyappliedforcesandtemperaturechangesinhardenedhydraulic-cementmortarandconcretespecimensmadeinthelaboratoryandexposedtocontrolledconditionsoftemperatureandmoisture.1.2ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Anexceptioniswithregardtosievesizesandnominalsizeofaggregate,inwhichtheSIvaluesarethestandardasstatedinSpecificationE11.Withinthetext,theSIunitsareshowninbrackets.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combin-ingvaluesfromthetwosystemsmayresultinnon-conformancewiththestandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2C125TerminologyRelatingtoConcreteandConcreteAggregatesC143/C143MTestMethodforSlumpofHydraulic-CementConcreteC172PracticeforSamplingFreshlyMixedConcreteC192/C192MPracticeforMakingandCuringConcreteTestSpecimensintheLaboratoryC305PracticeforMechanicalMixingofHydraulicCementPastesandMortarsofPlasticConsistencyC490PracticeforUseofApparatusfortheDeterminationofLengthChangeofHardenedCementPaste,Mortar,andConcreteC511SpecificationforMixingRooms,MoistCabinets,MoistRooms,andWaterStorageTanksUsedintheTestingofHydraulicCementsandConcretesC596TestMethodforDryingShrinkageofMortarCon-tainingHydraulicCementC1347PracticeforPreparationandDissolutionofUraniumMaterialsforAnalysisE11SpecificationforWireClothandSievesforTestingPurposesE337TestMethodforMeasuringHumiditywithaPsy-chrometer(theMeasurementofWet-andDry-BulbTem-peratures)3.Terminology3.1Definitions—ThetermsusedinthistestmethodaredefinedinTerminologyC125.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.1lengthchange,n—anincreaseordecreaseinthelengthofatestspecimenthathasbeencausedtochangebyanyfactorotherthanexternallyappliedforcesandtemperaturechanges.4.SignificanceandUse4.1Measurementoflengthchangepermitsassessmentofthepotentialforvolumetricexpansionorcontractionofmortarorconcreteduetovariouscausesotherthanappliedforceortemperaturechange.Thistestmethodisparticularlyusefulforcomparativeevaluationofthispotentialindifferenthydraulic-cementmortarorconcretemixtures.4.2Thistestmethodprovidesusefulinformationforexperi-mentalpurposesorforproductsthatrequiretestingundernonstandardmixing,placing,handling,orcuringconditions,suchashighproductworkabilityordifferentdemoldingtimes.Standardconditionsaredescribedin5.4.1.4.3Ifconditionsformixing,curing,sampling,andstorageotherthanspecifiedinthistestmethodarerequired,theyshallbereportedbutarenottobeconsideredasstandardconditions1ThistestmethodisunderthejurisdictionofASTMCommitteeC09onConcreteandConcreteAggregatesandisthedirectresponsibilityofSubcommitteeC09.68onVolumeChange.CurrenteditionapprovedOct.1,2008.PublishedNovember2008.Originallyapprovedin1940.Lastpreviouseditionapprovedin2006asC157/C157M–06.2ForreferencedASTMstandards,visittheASTMwebsite,@astm.org.ForAnnualBookofASTMStandardsvolumeinformation,refertothestandard’sDocumentSummarypageontheASTMwebsite.1*ASummaryofChangessectionappearsattheendofthisstandard.Copyright©ASTMInternational,100BarrHarborDrive,POBoxC700,WestConshohocken,PA19428-2959,UnitedStates.CopyrightASTMInternational,100BarrHarborDrive,WestConshohocken,Pennsylvania19428,USADistributedunderASTMlicenseagreementbyShanghaiInstituteofStandardization(SIS)Tel:[phone]ASTMInternational版本所有,100BarrHarborDrive,WestConshohocken,Pennsylvania,19428,USA由上海市标准化研究院（SIS）根据ASTM协议进行销售地址：上海市长乐路1219/1227号邮编：200031联系电话：86-21-64370807ofthistestmethod.Nonstandardconditionsandthereasonsfordeparturefromstandardconditionsshallbereportedclearlyandprominentlywithcomparatorvalues.5.Apparatus5.1MoldsandLengthComparator—ThemoldsforcastingtestspecimensandthelengthcomparatorformeasuringlengthchangeshallconformtotherequirementsofPracticeC490.5.2Tamper—Thetampershallbemadeofanonabsorptive,nonabrasivematerialsuchasmedium-hardrubberorseasonedoakwoodrenderednonabsorptivebyimmersionfor15mininparaffinatapproximately392°F[200°C],andshallhaveacrosssectionof1⁄2by1.0in.[13by25mm]andaconvenientlengthofabout6in.[150mm].Thetampingfaceofthetampershallbeflatandatrightanglestothelengthofthetamper.5.3TampingRod—Thetampingrodshallbeastraightsteelrod3⁄8in.[10mm]indiameterandnotlessthan10in.[250