ASTM D4643-2008 微波炉法测定土壤中含水量的标准试验方法

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【英文标准名称】:StandardTestMethodforDeterminationofWater(Moisture)ContentofSoilbyMicrowaveOvenHeating
【原文标准名称】:微波炉法测定土壤中含水量的标准试验方法
【标准号】:ASTMD4643-2008
【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】:D18.08
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:microwave;microwavemoisture;microwaveoven;moisturecontent;rapidmoisturetest;watercontent;Backfill--testing;Earthwork;Embankments;Fieldtesting--soil;Massperunitvolume;Microwaveovens/procedures;Ovens;Soil-aggregate;Soil-moisture
【摘要】:Thewatercontentofasoilisusedthroughoutgeotechnicalengineeringpracticebothinthelaboratoryandinthefield.TheuseofTestMethodD2216forwatercontentdeterminationcanbetimeconsumingandthereareoccasionswhenamoreexpedientmethodisdesirable.Theuseofamicrowaveovenisonesuchmethod.Theprincipalobjectiontotheuseofthemicrowaveovenforwater-contentdeterminationhasbeenthepossibilityofoverheatingthesoil,therebyyieldingawatercontenthigherthanwouldbedeterminedbyTestMethodD2216.Whilenoteliminatingthispossibility,theincrementaldryingproceduredescribedinthistestmethodwillminimizeitseffects.Somemicrowaveovenshavesettingsatlessthanfullpower,whichcanalsobeusedtoreduceoverheating.Thebehaviorofasoil,whensubjectedtomicrowaveenergy,isdependentonitsmineralogicalcompositions,andasaresultnooneprocedureisapplicableforalltypesofsoil.Therefore,theprocedurerecommendedinthistestmethodismeanttoserveasaguidewhenusingthemicrowaveoven.ThistestmethodisbestsuitedforminusNo.4sizedmaterial.Largersizeparticlescanbetested;however,caremustbetakenbecauseoftheincreasedchanceofparticleshattering.Theuseofthismethodmaynotbeappropriatewhenhighlyaccurateresultsarerequired,orthetestusingthedataisextremelysensitivetomoisturevariations.Duetothelocalizedhightemperaturesthatthespecimenisexposedtoinmicrowaveheating,thephysicalcharacteristicsofthesoilmaybealtered.Degregationofindividualparticlesmayoccur,alongwithvaporizationorchemicaltransition.Itisthereforerecommendedthatsamplesusedinthistestmethodnotbeusedforothertestssubsequenttodrying.Note18212;Thequalityoftheresultsproducedbythistestmethodisdependentonthecompetenceofthepersonnelperformingitandthesuitabilityoftheequipmentandfacilitiesused.AgenciesthatmeetthecriteriaofPracticeD3740aregenerallyconsideredcapableofcompetentandobjectivetesting.UsersofthistestmethodarecautionedthatcompliancewithPracticeD3740doesnotinitselfensurereliableresults.Reliableresultsdependonmanyfactors;PracticeD3740providesameansofevaluatingsomeofthosefactors.1.1Thistestmethodoutlinesproceduresfordeterminingthewater(moisture)contentofsoilsbyincrementallydryingsoilinamicrowaveoven.1.2ThistestmethodcanbeusedasasubstituteforTestMethodD2216whenmorerapidresultsaredesiredtoexpediteotherphasesoftestingandslightlylessaccurateresultsareacceptable.1.3WhenquestionsofaccuracybetweenthistestmethodandTestMethodD2216arise,TestMethodD2216shallbetherefereemethod.1.4Thistestmethodisapplicableformostsoiltypes.Forsomesoils,suchasthosecontainingsignificantamountsofhalloysite,mica,montmorillonite,gypsumorotherhydratedmaterials,highlyorganicsoils,orsoilsinwhichtheporewatercontainsdissolvedsolids(suchassaltinthecaseofmarinedeposits),thistestmethodmaynotyieldreliablewatercontentvalues.1.5ThevaluesstatedinSIunitsaretoberegardedasthestandard.Nootherunitsofmeasurementareincludedinthistestmethod.1.6RefertoPracticeD6026forguidanceconcerningtheuseofsignificantfigures.Thisisespeciallyimportantifthewatercontentwillbeusedtocalculateotherrelationshipssuchasmoistmasstodrymassorviceversa,wetunitweighttodryunitweightorvicevers......
【中国标准分类号】:B11
【国际标准分类号】:13_080_40
【页数】:6P.;A4
【正文语种】:英语