【英文标准名称】:StandardTestMethodforCBR(CaliforniaBearingRatio)ofSoilsinPlace
【原文标准名称】:现场测定土壤加利福尼亚承载比的标准试验方法
【标准号】:ASTMD4429-2009a
【标准状态】:现行
【国别】:美国
【发布日期】:2009
【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】:D18.08
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:bearingratio;CBR;deflection;flexiblepavement;CBR(Californiabearingratio);Soil
【摘要】:Fieldin-placeCBRtestsareusedforevaluationanddesignofflexiblepavementcomponentssuchasbaseandsubbasecourseandsubgradesandforotherapplications(suchasunsurfacedroads)forwhichCBRisthedesiredstrengthparameter.IfthefieldCBRistobeuseddirectlyforevaluationordesignwithoutconsiderationforvariationduetochangeinwatercontent,thetestshouldbeconductedunderoneofthefollowingconditions:(a)whenthedegreeofsaturation(percentageofvoidsfilledwithwater)is80%orgreater,(b)whenthematerialiscoarsegrainedandcohesionlesssothatitisnotsignificantlyaffectedbychangesinwatercontent,or(c)whenthesoilhasnotbeenmodifiedbyconstructionactivitiesduringthetwoyearsprecedingthetest.Inthelast-namedcase,thewatercontentdoesnotactuallybecomeconstant,butgenerallyfluctuateswithinarathernarrowrange.Therefore,thefieldin-placetestdatamaybeusedtosatisfactorilyindicatetheaverageload-carryingcapacity.Anyconstructionactivities,suchasgradingorcompacting,carriedoutsubsequenttothebearingratiotestwillprobablyinvalidatetheresultsofthetest.Soilsandflexiblepavementcomponentsatthesamelocationmayexhibitsignificantlydifferentloaddeflectionrelationships.Nomethodpresentlyexiststoevaluatetheprecisionofagroupofnon-repetitiveplateloadtestsonsoilsandflexiblepavementcomponentsduetothevariabilityofthesematerials.Note18212;Fieldin-placetestsareusedtodeterminetherelativestrengthofsoils,subbase,andsomebasematerialsintheconditionatwhichtheyexistatthetimeoftesting.Suchresultshavedirectapplicationintestsectionworkandinsomeexpedientconstruction,military,orsimilaroperations.Also,asindicatedin4.1,fieldin-placetestscanbeusedfordesignunderconditionsofnominalstabilityofwater,density,andgeneralcharacteristicsofthematerialtested.However,anysignificanttreating,disturbing,handling,compaction,orwaterchangecanaffectthesoilstrengthandmakethepriortotestdeterminationinapplicable,leadingtotheneedforretestandreanalysis.Note28212;Notwithstandingthestatementsonprecisionandbiascontainedinthisstandard:Theprecisionofthistestmethodisdependentonthecompetenceofthepersonnelperformingitandthesuitabilityoftheequipmentandfacilitiesused.AgencieswhichmeetthecriteriaofPracticeD3740aregenerallyconsideredcapableofcompetentandobjectivetesting.UsersofthismethodarecautionedthatcompliancewithPracticeD3740doesnotinitselfassurereliabletesting.Reliabletestingdependsonmanyfactors;PracticeD3740providesameansofevaluatingsomeofthosefactors.1.1ThistestmethodcoversthedeterminationoftheCaliforniaBearingRatio(CBR)ofsoiltestedinplacebythepenetrationloadofthesoil.Thistestmethodcoverstheevaluationoftherelativequalityofsubgradesoils,butisapplicabletosubbaseandsomebase-coursematerials.Thistestmethodisdesignedtotestin-situmaterialsandcorrespondstoTestMethodD1883.1.2ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefor......
【中国标准分类号】:P13
【国际标准分类号】:93_020
【页数】:7P.;A4
【正文语种】:英语