1、Designation:D5994/D5994M10(Reapproved 2021)Standard Test Method forMeasuring Core Thickness of Textured Geomembranes1This standard is issued under the fixed designation D5994/D5994M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the
2、 year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers a procedure to measure the corethickness of textured geomembranes.1.2 This test method doe
3、s not provide thickness values forgeomembranes under variable normal stresses.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system are not necessarily exact equivalents;therefore,toensure conformance with the standard,e
4、ach system shall beused independently of the other,and values from the twosystems shall not be combined.1.4 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,
5、and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of Internationa
6、l Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D4354 Practice for Sampling of Geosynthetics and RolledErosion Control Products(RECPs)for TestingD4439 Terminology for GeosyntheticsE177 P
7、ractice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE2554 Practice for Estimating and Monitoring the Uncer-tainty of Test Results of a Test Method Using ControlChart Techniques3.Terminology
8、3.1 For definitions of other terms relating to geomembranesused in this test method,refer to Terminology D4439.3.2 Definitions:3.2.1 core thickness,nthe average thickness of a texturedgeomembrane as measured using this particular test method.3.2.2 geomembrane,nan essentially impermeable geosyn-theti
9、c composed of one or more synthetic sheets.D44393.2.3 pressure,nthe force or load per unit area.3.2.4 textured geomembrane,na geomembrane havingone or both surfaces intentionally manufactured with projec-tions or indentations,most commonly for the purpose ofproviding increased shear strength against
10、 adjacent materials.3.2.5 thickness,nthe perpendicular distance between onesurface and its opposite.3.2.6 thickness gauge points,nthe tips of a thicknessgauge which contact the upper and lower geomembranesurfaces,and between which the thickness is measured.4.Summary of Test Method4.1 The core thickn
11、ess of a textured geomembrane iscalculated as the average value of measurements taken onreplicate specimens of the sample under investigation.Thethickness of each specimen is measured at a specific location asthe distance between two gauge points.The opposing thicknessgauge points are manufactured t
12、o a defined geometry,with aspecified force of 0.56 6 0.05 N 2.0 6 0.2 oz applied alongtheir axis.5.Significance and Use5.1 Thickness is one of the basic index properties used tocontrol and track the quality of many geomembranes.Additionally,many mechanical properties(for example,tensileyield strengt
13、h,puncture strength,etc.)can be related to corethickness.Core thickness values may also be required incalculation of some parameters such as diffusion coefficients ortensile stresses.5.2 The measured core thickness of geomembranes mayvary considerably depending on the pressure applied to the1This te
14、st method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.10 on Geomem-branes.Current edition approved July 1,2021.Published July 2021.Originally approvedin 1996.Last previous edition approved in 2015 as D5994/D5994M 10(2015)1.DOI:
15、10.1520/D5994_D5994M-10R21.2For 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 H
16、arbor 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.1specimen during measurement.To reduce variation in measure-ments and the chance of unrealistically low values due to
