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【英文标准名称】:StandardTestMethodsforDeterminingDispersiveCharacteristicsofClayeySoilsbytheCrumbTest
【原文标准名称】:用团粒试验测定粘性土的色散特性的标准试验方法
【标准号】:ASTMD6572-2006
【标准状态】:现行
【国别】:
【发布日期】:2006
【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】:D18.06
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:测定;土壤;试验方法;试验
【英文主题词】:clay(dispersive);colloidalerodability;crumbtestmethod;dispersibility;dispersion;dispersiveclays;erosion
【摘要】:Thecrumbtestmethodprovidesasimple,quickmethodforfieldorlaboratoryidentificationofadispersiveclaysoil.Theinternalerosionfailuresofanumberofhomogeneousearthdams,erosionalongchannelorcanalbanks,andrainfallerosionofearthenstructureshavebeenattributedtocolloidalerosionalongcracksorotherflowchannelsformedinmassesofdispersiveclay(5).Thecrumbtestmethod,asoriginallydevelopedbyEmerson(6),wascalledtheaggregatecoherencetestandhadsevendifferentcategoriesofsoil-waterreactions.Sherard(5)latersimplifiedthetestbycombiningsomesoil-waterreactionssothatonlyfourcategories,orgrades,ofsoildispersionareobservedduringthetest.Thecrumbtestisarelativelyaccuratepositiveindicatorofthepresenceofdispersivepropertiesinasoil.Thecrumbtest,however,isnotacompletelyreliablenegativeindicatorthatsoilsarenotdispersive.Thecrumbtest,canseldomberelieduponasasoletestmethodfordeterminingthepresenceofdispersiveclays.Thedouble-hydrometertest(TestMethodD4221)andpinholetest(TestMethodD4647)aretestmethodsthatprovidevaluableadditionalinsightintotheprobabledispersivebehaviorofclaysoils.Note28212;Thequalityoftheresultproducedbythesetestmethodsisdependentonthecompetenceofthepersonnelperformingit,andthesuitabilityoftheequipmentandfacilitiesused.AgenciesthatmeetthecriteriaofPracticeD3740aregenerallyconsideredcapableofcompetentandobjectivetesting.UsersofthesetestmethodsarecautionedthatcompliancewithPracticeD3740doesnotinitselfensurereliabletesting.Reliabletestingdependsonseveralfactors;PracticeD3740providesameansofevaluatingsomeofthosefactors.1.1Thesetestmethodsprovideaqualitativeindicationofthenaturaldispersivecharacteristicsofclayeysoils.1.2Thesetestmethodsarenotapplicableforsoilswithlessthan12%fractionfinerthan0.005mmandwithaplasticityindexlessthanorequalto8.1.3Thecrumbtestmethodhassomelimitationsinitsusefulnessasanindicatorofdispersiveclay.Adispersivesoilmaysometimesgiveanondispersivereactioninthecrumbtest.Soilscontainingkaolinitewithknownfielddispersionproblemshaveshownnondispersivereactionsinthecrumbtest().However,ifthecrumbtestindicatesdispersion,thesoilisprobablydispersive.1.4Oven-driedsoilshouldnotbeusedtopreparecrumbtestspecimens,asirreversiblechangescouldoccurtothesoilpore-waterphysicochemicalpropertiesresponsiblefordispersion().1.5Thecrumbtestmethod,whileagoodquickindicationofdispersiveclay,shouldusuallyberuninconjunctionwithapinholetestandadoublehydrometertest,TestMethodsD4647andD4221,respectively.Note1Insomecases,theresultsofthepinhole,crumb,anddouble-hydrometertestmethodsmaydisagree.Crumbtestmethodsareabetterindicatorofdispersiveclaysthanofnondispersiveclays().1.6ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:B11
【国际标准分类号】:13_080_20
【页数】:5P.;A4
【正文语种】: