Designation:D6693/D6693M−20StandardTestMethodforDeterminingTensilePropertiesofNonreinforcedPolyethyleneandNonreinforcedFlexiblePolypropyleneGeomembranes1ThisstandardisissuedunderthefixeddesignationD6693/D6693M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationofthetensilepropertiesofnonreinforcedgeomembranesintheformofstandarddumbbell-shapedtestspecimenswhentestedunderdefinedconditionsofpretreatment,temperature,andmachinespeed.1.2Thistestmethodcanbeusedfortestingmaterialsthicknessbetween0.25mm[0.010in.]and6.3mm[0.25in.].NOTE1—Thistestmethodisnotintendedtopreciselymeasurephysicalpropertiesofageomembranefordesignpurposes.Thisisan“indextest”intendedtobeusedforqualitycontrolandspecificationconformancepurposes.Theconstantrateofcrossheadmovementofthistestlacksaccuracyfromatheoreticalstandpoint,sincecrossheadmovementasopposedtoactualstrainisused.Awidedifferencemayexistbetweentherateofcrossheadmovementandtherateofstraininparticularareasofthespecimensincethespecimendoesnothaveauniformwidthorcross-sectionalarea.Thismaydisguiseimportanteffectsorcharacteristicsofthesematerialsintheplasticstate.Useofanextensometer,notincludedinthistest,wouldmoreaccuratelymeasurestrainandstrainratebutwouldstillhavelimitationsforsomegeomembranes.Further,itisrealizedthatvariationsinthethicknessesoftestspecimens,aspermittedbythistestmethod,producevariationsinthesurface-volumeratiosofsuchspecimens,andthatthesevariationsmayinfluencethetestresults.Hence,wheredirectlycomparableresultsaredesired,allsamplesshouldbeofequalthickness.Specialadditionaltestsshouldbeusedwheremoreprecisephysicaldataareneeded.TestMethodD4885isasuitableperformancetestformanyapplications.1.3ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thev...
