1、Designation:D774911(Reapproved 2018)Standard Test Method forDetermining Integrity of Seams Produced Using Thermo-Fusion Methods for Reinforced Geomembranes by the GrabMethod1This standard is issued under the fixed designation D7749;the number immediately following the designation indicates the year
2、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 describes destructive quality controltests used
3、 to determine the integrity of thermo-fusion seamsmade with reinforced geomembranes.A test procedure isdescribed that uses seam tests using grab specimens for seamshear strength.1.2 The types of thermal field and factory seaming tech-niques used to construct geomembrane seams include thefollowing:1.
4、2.1 Hot AirThis technique introduces high-temperatureair between two geomembrane surfaces to facilitate melting.Pressure is applied to the top or bottom geomembrane,forcingtogether the two surfaces to form a continuous bond.1.2.2 Hot WedgeThis technique melts the two geomem-brane surfaces to be seam
5、ed by running a hot metal wedgebetween them.Pressure is applied to the top and bottomgeomembrane to form a continuous bond.Some seams of thiskind are made with dual tracks separated by a non-bonded gap.These seams are sometimes referred to as dual hot wedgeseams or double-track seams.1.2.3 Extrusion
6、This technique encompasses extrudingmolten resin between two geomembranes or at the edge of twooverlapped geomembranes to effect a continuous bond.1.2.4 Radio Frequency(RF)or DielectricHigh-frequencydielectric equipment is used to generate heat and pressure toform an overlap seam in factory fabricat
7、ion.1.2.5 ImpulseClamping bars heated by wires or a ribbonmelt the sheets clamped between them.A cooling period whilestill clamped allows the polymer to solidify before beingreleased.1.3 The types of materials covered by this test methodinclude,but are not limited to,reinforced geomembranes madefrom
8、 the following polymers:1.3.1 Very low-density polyethylene(VLDPE).1.3.2 Linear low-density polyethylene(LLDPE).1.3.3 Flexible polypropylene(fPP).1.3.4 Polyvinyl chloride(PVC).1.3.5 Chlorosulfonated polyethylene(CSPE).1.3.6 Ethylene interpolymer alloy(EIA).1.4 UnitsThe values stated in either SI uni
9、ts or inch-pound units are to be regarded separately as standard.Thevalues stated in each system may not be exact equivalents;therefore,each system shall be used independently of the other.Combining values from the two systems may result in noncon-formance with the standard.1.5 This standard does no
10、t 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.1.6 This international standa
11、rd 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.Referen
12、ced Documents2.1 ASTM Standards:2D76/D76M Specification for Tensile Testing Machines forTextilesD4439 Terminology for GeosyntheticsD7003/D7003M Test Method for Strip Tensile Properties ofReinforced GeomembranesD7004/D7004M Test Method for Grab Tensile Properties ofReinforced GeomembranesD7747/D7747M
13、 Test Method for Determining Integrity ofSeams Produced Using Thermo-Fusion Methods for Re-inforced Geomembranes by the Strip Tensile Method1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.10 on Geomem-branes.Curre
14、nt edition approved Feb.1,2018.Published February 2018.Originallyapproved in 2011.Last previous edition approved in 2011 as D7749 11.DOI:10.1520/D7749-11R18.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMSt
15、andards 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
16、 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.1 3.Terminology3.1 DefinitionsRefer to Terminology D4439 for defini-tions of terms applying to this test method.4.Significance and Use4.1 The use of reinforced geomembranes as barrier materi-als has created a need for a standard test method to evaluate thequality of seams produced by th
