ASTM_D_7747_-_D_7747M_-_11e1.pdf

Designation:D7747/D7747M111Standard Test Method forDetermining Integrity of Seams Produced Using Thermo-Fusion Methods for Reinforced Geomembranes by the StripTensile Method1This standard is issued under the fixed designation D7747/D7747M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the 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.1NOTEDesignation was corrected and editorial changes were made throughout in October 2013.1.Scope1.1 This test method describes destructive quality controltests used to determine the integrity of thermo-fusion seamsmade with reinforced geomembranes.Test procedures aredescribed for seam tests for peel and shear properties usingstrip specimens.1.2 The types of thermal field and factory seaming tech-niques used to construct geomembrane seams include thefollowing:1.2.1 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 seamed 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 ExtrusionThis 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 fabrication.1.2.5 ImpulseClamping bars heated by wires or a ribbonmelts the sheets clamped between them.Acooling 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 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 units 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 non-conformance with the standard.1.5 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D76/D76M Specification for Tensile Testing Machines forTextilesD7003/D7003M Test Method for Strip Tensile Properties ofReinforced GeomembranesD7004/D7004M Test Method for Grab Tensile Properties ofReinforced GeomembranesD4439 Terminology for GeosyntheticsD7749 Test Method for Determining Integrity of SeamsProduced Using Thermo-Fusion Methods for ReinforcedGeomembranes by the Grab Method3.Terminology3.1 DefinitionsRefer to Terminology for Geosynthetics,D4439,for definitions of terms applying to this test method.1This test 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 Oct.1,2011.Published October 2011.DOI:10.1520/D7747_D7747M11E01.2For 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 States1 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 thermo-fusion methods.This testmethod is used for quality control purposes and is intended toprovide quality control and quality assurance personnel withdata to evaluate seam quality.4.2 This standard arose from the need for a destructive testmethod for evaluating seams of reinforced geomembranes.Standards written for destructive testing of nonreinforcedgeomembranes do not include all Break Codes(Fig.1)applicable to reinforced geomembranes.4.3 When reinforcement occurs in directions other thanmachine and cross machine,scrim are cut at specimen edges,generally lowering results.To partially compensate for this,testing ca