Designation:D2844/D2844M−18StandardTestMethodforResistanceR-ValueandExpansionPressureofCompactedSoils1ThisstandardisissuedunderthefixeddesignationD2844/D2844M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoverstheprocedurefortestingbothtreatedanduntreatedlaboratorycompactedsoilsoraggregateswiththestabilometerandexpansionpressuredevicestoobtainresultsindicativeofperformancewhenplacedinthebase,subbase,orsubgradeofaroadsubjectedtotraffic.1.2Units—ThevaluesstatedineitherSIunitsorinch-poundunitspresentedinbracketsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnon-conformancewiththestandard.However,useofequipmentmanufacturedtobereadableininch-poundunitsonlyshouldnotbeconsideredasnon-conformancetothetestmethod.Manystabilometersandexpansionpressuredevicesaremanufacturedtobereadableininch-poundunitsonly.1.3AllobservedandcalculatedvaluesshallconformtotheguidelinesforsignificantdigitsandroundingestablishedinPracticeD6026.1.3.1Forpurposesofcomparingmeasuredorcalculatedvalue(s)withspecifiedlimits,themeasuredorcalculatedvalue(s)shallberoundedtothenearestdecimalorsignificantdigitsinthespecifiedlimits.1.3.2Theproceduresusedtospecifyhowdataarecollected/recordedorcalculated,inthisstandardareregardedastheindustrystandard.Inaddition,theyarerepresentativeofthesignificantdigitsthatgenerallyshouldberetained.Theproce-duresuseddonotconsidermaterialvariation,purposeforobtainingthedata,specialpurposestudies,oranyconsider-ationsfortheuser’sobjectives;anditiscommonpracticetoincreaseorreducesignificantdigitsofreporteddatatobecommensuratewiththeseconsiderations.Itisbeyondthescopeofthisstandardtoconsidersignificantdigitsus...
