Designation:D7382−20StandardTestMethodsforDeterminationofMaximumDryUnitWeightofGranularSoilsUsingaVibratingHammer1ThisstandardisissuedunderthefixeddesignationD7382;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thesetestmethodscoverthedeterminationofthemaximumdryunitweightofgranularsoils.Avibratinghammerisusedtoimpartasurchargeandcompactiveefforttothesoilspecimen.Further,anoptionalcalculationispresentedtodeterminetheapproximatewatercontentrangeforeffectivecompactionofgranularsoilsbasedonthemeasuredmaximumdrydensityandspecificgravity.1.2Thesetestmethodsapplytoprimarilygranular,free-drainingsoilsforwhichimpactcompactiondoesnotyieldaclearoptimumwatercontent.Specifically,thesetestmethodsapplytosoils:1.2.1withupto35%,bydrymass,passingaNo.200(75-µm)sieveiftheportionpassingtheNo.40(425-µm)sieveisnonplastic;1.2.2withupto15%,bydrymass,passingaNo.200(75-µm)sieveiftheportionpassingtheNo.40(425-µm)sieveexhibitsplasticbehavior.1.3Further,duetolimitationsofthetestingequipment,andtheavailableoversizecorrectionproceduresthesetestmethodsapplytosoilsinwhich:1.3.1lessthan30%,bydrymass,isretainedonthe3⁄4-in.(19.0-mm)sieve,orinwhich1.3.2100%,bydrymass,passesthe2-in.(50-mm)sieve.1.4Thesetestmethodswilltypicallyproduceahighermaximumdryunitweightforthesoilsspecifiedin1.2.1and1.2.2thanthatobtainedbyimpactcompactioninwhichawell-definedmoisture-densityrelationshipisnotapparent.However,forsomesoilscontainingmorethan15%fines,theuseofimpactcompaction(TestMethodsD698orD1557)maybeusefulinevaluatingwhatisanappropriatemaximumindexunitweight.1.5Fouralternativetestmethodsareprovided,withthevariationbeinginsaturatedversusdryspecimensandmoldsize.Themethodusedshallbeasindicatedinthespecificationforthematerialbeingtested.Ifnomethodisspecified,thechoiceshouldbebasedonthemaximumpar...
