ASTM_D_6766_-_20a.pdf

Designation:D676620aStandard Test Method forEvaluation of Hydraulic Properties of Geosynthetic ClayLiners Permeated with Potentially Incompatible AqueousSolutions1This standard is issued under the fixed designation D6766;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers laboratory measurement of bothflux and hydraulic conductivity(also referred to as coeffcientof permeability)of geosynthetic clay liner(GCL)specimenspermeated with chemical solutions and leachates utilizing aflexible wall permeameter.For test measurement of indexhydraulic properties of geosynthetic clay liners,refer to TestMethod D5887/D5887M.For hydraulic conductivity compat-ibility of soils with aqueous chemical solutions and leachates,refer to Test Method D7100.1.2 This test method may be utilized with GCL specimensthat have a hydraulic conductivity less than or equal to1 105ms(1 103cm/s).1.3 This test method is applicable to GCL products havinggeotextile backing(s).It is not applicable to GCL products withgeomembrane backing(s),geofilm backing(s),or polymer coat-ing backing(s).1.4 This test method allows the requester to evaluate thehydraulic properties of a GCL with site-specific or laboratory-prepared solution under different test conditions;thus,the testmethod also may be used to check performance orconformance,or both.1.5 The values stated in SI units are to be regarded as thestandard,unless other units are specifically given.By traditionin U.S.practice,hydraulic conductivity is reported in centime-ters per second,although the common SI units for hydraulicconductivity are meters per second.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil,Rock,and ContainedFluidsD854 Test Methods for Specific Gravity of Soil Solids byWater PycnometerD2216 Test Methods for Laboratory Determination of Water(Moisture)Content of Soil and Rock by MassD4439 Terminology for GeosyntheticsD4753 Guide for Evaluating,Selecting,and Specifying Bal-ances and Standard Masses for Use in Soil,Rock,andConstruction Materials TestingD5887/D5887M Test Method for Measurement of IndexFlux Through Saturated Geosynthetic Clay Liner Speci-mens Using a Flexible Wall PermeameterD7100 Test Method for Hydraulic Conductivity Compatibil-ity Testing of Soils with Aqueous SolutionsE145 Specification for Gravity-Convection and Forced-Ventilation Ovens3.Terminology3.1 Definitions:3.1.1 flux,nthe rate of discharge of liquid under laminarflow conditions through a unit cross-sectional area of a GCLspecimen at a standard temperature condition(22 6 3 C).3.1.2 geosyntheticclayliner(GCL),nafactory-manufactured geosynthetic hydraulic barrier consisting of claysupported by geotextiles,geomembranes,or a combination1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.04 on Geosyn-thetic Clay Liners.Current edition approved May 1,2020.Published May 2020.Originallyapproved in 2002.Last previous edition approved in 2020 as D6766 20.DOI:10.1520/D6766-20A.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.thereof,that are held together by needling,stitching,chemicaladhesives,or other methods.3.1.3 hydraulic conductivity,k,nthe rate of discharge ofliquid under laminar flow conditions through a unit cross-sectional area of a GCL specimen under a unit hydraulicgradient and standard temperature conditions(22 6 3 C).3.1.3.1 DiscussionThe term coeffcient of permeability isoften used instead of hydraulic conductivity,but hydrauliccon