ASTM D4944-2004 用碳化钙气压检验器法现场测定土壤中水含量的标准试验方法

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【英文标准名称】:StandardTestMethodforFieldDeterminationofWater(Moisture)ContentofSoilbytheCalciumCarbideGasPressureTester
【原文标准名称】:用碳化钙气压检验器法现场测定土壤中水含量的标准试验方法
【标准号】:ASTMD4944-2004
【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】:D18.08
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:土壤;含水量;试验;土壤分析
【英文主题词】:acceptancetest;calciumcarbide;gaspressure;moisturecontent;pressure-measuringinstrument;quicktest;soilmoisture;soilwatercontent;watercontent
【摘要】:Thewatercontentofsoilisusedthroughoutgeotechnicalengineeringpractice,bothinthelaboratoryandinthefield.Resultsaresometimesneededwithinashorttimeperiodandinlocationswhereitisnotpracticaltoinstallanovenortotransportsamplestoanoven.Thistestmethodisusedfortheseoccasions.Theresultsofthistesthavebeenusedforfieldcontrolofcompactedembankmentsorotherearthstructuressuchasinthedeterminationofwatercontentforcontrolofsoilmoistureanddrydensitywithinaspecifiedrange.ThistestmethodrequiresspecimensconsistingofsoilhavingallparticlessmallerthantheNo.4sievesize.ThistestmethodmaynotbeasaccurateasotheracceptedmethodssuchasTestMethodD2216.Inaccuraciesmayresultbecausespecimensaretoosmalltoproperlyrepresentthetotalsoil,fromclumpsofsoilnotbreakinguptoexposealltheavailablewatertothereagentandfromotherinherentprocedural,equipmentorprocessinaccuracies.Therefore,othermethodsmaybemoreappropriatewhenhighlyaccurateresultsarerequired,orwhentheuseoftestresultsissensitivetominorvariationsinthevaluesobtained.Note18212;Thequalityoftheresultproducedbythisstandardisdependentonthecompetenceofthepersonnelperformingit,andthesuitabilityoftheequipmentandfacilitiesused.AgenciesthatmeetthecriteriaofPracticeD3740aregenerallyconsideredcapableofcompetentandobjectivetesting/sampling/inspection.UsersofthisstandardarecautionedthatcompliancewithPracticeD3740doesnotinitselfensurereliableresults.Reliableresultsdependonmanyfactors;PracticeD3740providesameansofevaluatingsomeofthosefactors.1.1Thistestmethodoutlinesproceduresfordeterminingthewater(moisture)contentofsoilbychemicalreactionusingcalciumcarbideasareagenttoreactwiththeavailablewaterinthesoilproducingagas.Ameasurementismadeofthegaspressureproducedwhenaspecifiedmassofwetormoistsoilisplacedinatestingdevicewithanappropriatevolumeofreagentandmixed.1.2ThistestmethodisnotintendedasareplacementforTestMethodD2216;butasasupplementwhenrapidresultsarerequired,whentestingisdoneinfieldlocations,orwhereanovenisnotpracticalforuse.TestMethodD2216istobeusedasthetestmethodtocompareforaccuracychecksandcorrection.1.3Thistestmethodisapplicableformostsoils.Calciumcarbide,usedasareagent,reactswithwaterasitismixedwiththesoilbyshakingandagitatingwiththeaidofsteelballsintheapparatus.Toproduceaccurateresults,thereagentmustreactwithallthewaterwhichisnotchemicallyhydratedwithsoilmineralsorcompoundsinthesoil.Somehighlyplasticclaysoilsorothersoilsnotfriableenoughtobreakupmaynotproducerepresentativeresultsbecausesomeofthewatermaybetrappedinsidesoilclodsorclumpswhichcannotcomeincontactwiththereagent.Theremaybesomesoilscontainingcertaincompoundsorchemicalsthatwillreactunpredictablywiththereagentandgiveerroneousresults.AnysuchproblemwillbecomeevidentascalibrationorchecktestswithTestMethodD2216aremade.Somesoilscontainingcompoundsormineralsthatdehydratewithheat(suchasgypsum)whicharetohavespecialtemperaturecontrolwithTestMethodD2216maynotbeaffected(dehydrated)inthistestmethod.1.4Thistestmethodislimitedtousingcalciumcarbidemoisturetestequipmentmadefor20g,orlarger,soilspecimensandtotestingsoilwhichcontainsparticlesnolargerthantheNo.4Standardsievesize.Thisstandarddoesnotpurporttoaddres......
【中国标准分类号】:B11
【国际标准分类号】:
【页数】:5P.;A4
【正文语种】: