Designation:C918/C918M−13StandardTestMethodforMeasuringEarly-AgeCompressiveStrengthandProjectingLater-AgeStrength1ThisstandardisissuedunderthefixeddesignationC918/C918M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoversaprocedureformakingandcuringconcretespecimensandfortestingthematanearlyage.Thespecimensarestoredunderstandardoracceleratedcuringconditionsandthemeasuredtemperaturehistoryisusedtocomputeamaturityindexthatisrelatedtostrengthgain.1.2Thistestmethodalsocoversaprocedureforusingtheresultsofearly-agecompressive-strengthteststoprojectthepotentialstrengthofconcreteatlaterages.1.3ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnon-conformancewiththestandard.1.4Thetextofthisstandardreferencesnotesandfootnoteswhichprovideexplanatorymaterial.Thesenotesandfootnotes(excludingthoseintablesandfigures)shallnotbeconsideredasrequirementsofthestandard.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.(Warning—Freshhydrauliccementitiousmixturesarecausticandmaycausechemicalburnstoskinandtissueuponprolongedexposure.)22.ReferencedDocuments2.1ASTMStandards:3C31/C31MPracticeforMakingandCuringConcreteTestSpecimensintheFieldC39/C39MTestMethodforCompressiveStrengthofCylin-dricalConcreteSpecimensC192/C192MPracticeforMakingandCuringConcreteTestSpecimensintheLaboratoryC470/C470MSpecificationforMoldsforFormingConcreteTestCylindersVerticallyC617/C617MPracticeforCappingCylindrica...
