ASTM C1556-2004 用粒状料扩散法测定水泥混合物表面氯化物扩散系数的标准试验方法

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【英文标准名称】:StandardTestMethodforDeterminingtheApparentChlorideDiffusionCoefficientofCementitiousMixturesbyBulkDiffusion
【原文标准名称】:用粒状料扩散法测定水泥混合物表面氯化物扩散系数的标准试验方法
【标准号】:ASTMC1556-2004
【标准状态】:现行
【国别】:
【发布日期】:2004
【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】:C09.66
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:测定;扩散系数;表观;氯化物;混合物;扩散
【英文主题词】:chloride;concrete;corrosion;diffusion;iontransport;servicelife
【摘要】:Thistestmethodisapplicabletocementitiousmixturesthathavenotbeenexposedtoexternalchlorideions,otherthanthenegligiblequantityofchlorideionexposurefromsamplepreparationusingpotablewater,priortothetest.Thecalculationproceduredescribedinthistestmethodisapplicableonlytolaboratorytestspecimensexposedtoasodiumchloridesolutionasdescribedinthistestmethod.Thiscalculationprocedureisnotapplicabletospecimensexposedtochlorideionsduringcyclicwettinganddrying.Note18212;Thediffusionofionicspeciesinconcreteoccurswithinthefluid-filledpores,cracksandvoidspaces.Theconcentrationandvalenceofotherionicspeciesintheporefluidalsoinfluencetherateofchloridediffusion,andtherefore,theapparentdiffusioncoefficientasdeterminedbythistestprocedure.Inmostcases,thevalueoftheapparentchloridediffusioncoefficientforcementitiousmixtureschangesovertime(SeeNote2).Therefore,apparentdiffusioncoefficientsobtainedatearlyagesmaynotberepresentativeofperformanceinservice.Note28212;Therateofchangeoftheapparentdiffusioncoefficientforcementitiousmixturescontainingpozzolansorblast-furnaceslagistypicallydifferentthanthatformixturescontainingonlyportlandcement.TheapparentchloridediffusioncoefficientisusedinFickrsquo;secondlawofdiffusiontoestimatechloridepenetrationintocementitiousmixturesthatareinasaturatedcondition.TheapparentchloridediffusioncoefficientiscommonlyusedinchlorideingressmodelsbasedonFickrsquo;secondlawofdiffusion.Theapparentdiffusioncoefficientdeterminedbythismethodincludeschemicallyboundchloride,soproperuseoftheapparentchloridediffusioncoefficienttopredictchlorideingressrequiresconsiderationofchloridebinding.Theresistancetochloridepenetrationisaffectedbysuchfactorsastheenvironment,finishing,mixturecomposition,workmanship,curing,andage.1.1Thistestmethodcoversthelaboratorydeterminationoftheapparentchloridediffusioncoefficientforhardenedcementitiousmixtures.1.2ThevaluesstatedinSIunitsaretoberegardedasthestandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:Q13
【国际标准分类号】:71_060_99
【页数】:7P.;A4
【正文语种】: