Designation:D7406−20StandardTestMethodforTime-DependentCompressiveDeformationUnderConstantPressureforGeosyntheticDrainageProducts1ThisstandardisissuedunderthefixeddesignationD7406;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodisusedtodeterminetheunconfinedcompressivedeformation(consolidation)characteristicsofdrainagegeotextiles,geocomposites,geonets,oranyothergeosyntheticassociatedwithdrainageataconstanttemperature,whensubjectedtoaconstantcompressivestress.1.2Thistestmethodisintendedforuseasanunconfinedcompressiveperformancedeformationtestonly.Foradetailedprocedureonhowtoestablishanindextest,seeENISO25619-1.Forperformancetests,thespecimenshallbesub-jectedtothesite-specificliquid,thesite-specificstress(normalandpotentiallyatangentialstressontheupperandparallelloadingplaten),orboth.NOTE1—Resultsachievedfromunconfinedcompressiveperformancedeformationtestingmaydifferfromtestingperformedunderconfinedconditions.1.3Becauseofthechangingnatureofthegeosyntheticindustryandthewidevarietyofproductsalreadyavailable,thisparticulartestmethodmayhavetobeslightlymodifiedforunconfinedcompressiondeformationtestingofsomeproducts.1.4ThevaluesgiveninSIunitsaretobeconsideredasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.6Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(T...
