【英文标准名称】:StandardTestMethodforEarlyStiffeningofHydraulicCement(PasteMethod)
【原文标准名称】:水硬水泥的早硬化的标准试验方法(水泥浆法)
【标准号】:ASTMC451-2008
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【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】:C01.30
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:earlystiffening;falseset;flashset;hydraulic-cementpaste;Vicat.;Earlystiffening;Hydrauliccement;Mortar(portlandcementmortar);Pastemethod;Portlandcement;Stiffness
【摘要】:Thepurposeofthistestmethodistodeterminethedegreetowhichacementpastedevelopsearlystiffeningortoestablishwhetherornotacementcomplieswithaspecificationlimitonearlystiffening.Whenusedforestablishingcompliancewithaspecificationlimit,thespecificationrequirementiscustomarilystatedintermsoftheminimumallowablefinalpenetration,inpercent,calculatedinaccordancewiththeCalculationSection.Whenusedforestimatingtherelativetendencyofacementtomanifestearlystiffening,additionalinformationofvaluemaybeobtainediftheremixproceduredescribedintheProcedureSectionisemployed.Undersomeconditions,ajudgmentmaybemadebycomparingthebehaviorintheinitialtestandintheremixproceduretodifferentiatearelativelylessseriousandlesspersistenttendencytoearlystiffening(falseset)fromonethatismorepersistentand,consequently,moreserious(flashset).Severefalsesettinginacementmaycausedifficultyfromaplacingandhandlingstandpoint,butitisnotlikelytocausedifficultieswhereconcreteismixedforalongertimethanusual,asusuallyoccursintransitmixing,orwhereitisremixedpriortoplacingortransporting,asoccursinconcretepumpingoperations.Itismostlikelytobenoticeablewhereconcreteismixedforashortperiodoftimeinstationarymixersandtransportedtotheformsinnon-agitatingequipment,suchasonsomepavingjobs,andwhenconcreteismadeinanon-sitebatchplant.Cementswithseverefalsesettingusuallyrequireslightlymorewatertoproducethesameconsistency,whichmaybeexpectedtoresultinslightlylowerstrengthsandincreaseddryingshrinkage.Earlystiffeningresultingfromfalsesetisnotlikelytocauseacementtofailtheapplicabletimeofsettingrequirement.Earlystiffeningresultingfromflashset,dependingonseverity,cancauseacementtofailtheapplicabletimeofsettingrequirement.1.1Thistestmethodcoversthedeterminationofearlystiffeninginhydraulic-cementpaste.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.Warningx2014;Freshhydraulic-cementitiousmixturesarecausticandmaycausechemicalburnstoskinandtissueuponprolongedexposure.Theuseofgloves,protectiveclothing,andeyeprotectionisrecommended.Washcontactareawithcopiousamountsofwateraftercontact.Washeyesforaminimumof15min.Avoidexposureofthebodytoclothingsaturatedwiththeliquidphaseoftheunhardenedmaterial.Removecontaminatedclothingimmediatelyafterexposure.1.4Thetextofthisstandardreferencesnotesandfootnoteswhichprovideexplanatorymaterial.Thesenotesandfootnotes(excludingthoseintablesandfigures)shallnotbeconsideredasrequirementsofthestandard.
【中国标准分类号】:Q11
【国际标准分类号】:91_100_10
【页数】:4P.;A4
【正文语种】:英语