1、Designation: D7747/D7747M 111Standard 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
2、 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 m
3、ade 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
4、 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 s
5、urfaces 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 n
6、on-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 DielectricH
7、igh 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
8、 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.
9、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
10、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 healt
11、h 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 Gr
12、ab 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 defin
13、itions 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 r
14、eferenced 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, W
15、est Conshohocken, PA 19428-2959. United States14. 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
16、 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 in
17、clude 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 can be performed according to Test Method D7749,or
18、the 2 in. wide strip specimen specified in this method can beutilized. Testing of 1 in. and 2 in. specimens is Method A andMethod B respectively.4.4 The shear test outlined in this method correlates tostrength of parent material measured according to Test MethodD7003/D7003M only if reinforcement is
19、parallel to TD. Forother materials, seam strength and parent material strength canbe compared through Test Methods D7749 and D7004/D7004M. Values obtained with the strip methods shall not becompared to values obtained with grab methods.5. Apparatus5.1 Tensile Testing MachineConstant Rate of Extensio
20、n(CRE) equipment meeting the requirements of SpecificationD76/D76M. The load cell shall be accurate to within 61%ofthe applied force. The drive mechanism shall be able to controlthe rate of extension to within 61 % of the targeted rate. Themaximum allowable error in recorded grip displacement shallb
21、e 61 % of the recorded values. The maximum allowablevariation in nominal gage length on repeated return of theclamps to their starting position shall be less than 0.25 mm0.01 in.5.2 Grip FacesThe clamping force and the clamp surfacesshall hold the specimen firmly without causing damage.5.2.1 Clamp f
22、aces shall be a minimum of 25.4 mm 1.00 in.in the dimension parallel to direction of test and wide enoughto grip the full width of the specimen.6. Sample and Specimen Preparation6.1 Seam SamplesApproximately 1 m 36 in. length ofseam shall be cut out with a minimum of 12.5 cm 5 in. ofmaterial on eith
23、er side of the seam.6.2 Specimen PreparationFive specimens each for peelstrength and shear strength. The locations from which thespecimens are taken shall be spaced evenly along the length ofthe seam with shear and peel specimens alternating along thesample length (Fig. 2).6.2.1 SpecimensRectangular
24、 test specimens shall be aminimum of 150 mm 6.0 in. plus the seam width in thedirection perpendicular to the seam. For Method A, thespecimens shall be 25.4 mm 1.00 in. in the direction parallelto the seam. For Method B, specimens shall be 50.8 mm 2.00in. in the direction parallel to the seam. The se
25、am should becentered in the specimen.7. Conditioning7.1 ConditioningSpecimens may be tested once they haveequilibrated at standard laboratory temperature. The timerequired to reach temperature equilibrium may vary accordingto the material type and thickness.7.2 Test ConditionsConduct tests at the st
26、andard atmo-sphere for testing geosynthetics, a temperature of 21 6 2C 706 4F and a relative humidity between 50 to 70 %, unlessotherwise specified.8. Procedure8.1 Shear Test:8.1.1 Set the grip separation equal to the width of the seamplus 76.2 mm 3.00 in. Set the crosshead speed to 305mm/min 12 in/
27、min.8.1.2 Place the specimen symmetrically in the clamps so theweld will experience shear force (Fig. 3). Center the seamvertically between the grips.8.1.3 Elongate the specimen until rupture of reinforcementand coating or until a separation of weld or separation in planehas occurred across the enti
28、re weld. (See Fig. 1 for explanationof separation in plane.)8.1.4 Record the load at peak and Break Code (Fig. 4 andFig. 1).8.2 Peel Test:8.2.1 Set the grip separation to 25.4 mm/min 1.00 in. Setthe crosshead speed to 50.8 mm/min 2.00 in./min.8.2.2 Place the specimen in the clamps in a “T” configura
29、-tion (Fig. 4). If there is enough material, center the seamvertically between the grips.8.2.3 Elongate the specimen until rupture of reinforcementand coating or until a separation of weld or separation in planehas occurred across the entire weld. (See Fig. 1 for explanationof separation in plane.)8
30、.2.4 If a specimen slips between the clamps, discard theindividual result and test another specimen. If reinforcingstrands slip through the material held between the grips,discard the individual result and test another specimen. Slip-ping scrim may require increasing clamping pressure.8.2.5 Record t
31、he load at peak, and Break Code (see Fig. 1and Fig. 5).9. Calculation9.1 Seam Shear Strength:9.1.1 Divide the peak load by the width of the specimen toobtain results in N/mm or lbs/in.9.2 Seam Peel Strength:9.2.1 Divide the peak load by the width of the specimen toobtain results in N/mm or lbs/in.NO
32、TE 1Because of the heterogonous nature of a reinforcedgeomembranes, calculating force per cross-sectional area is not relevantand should not be done.D7747/D7747M 1112FIG. 1 Break Codes for Dual Hot Wedge and Hot Air Seams of Reinforced Geomembranes Tested for Seam Strengthin Shear and Peel ModesD774
33、7/D7747M 1113FIG. 2 Specimen Configuration of Seam SampleFIG. 3 Example of Shear TestFIG. 4 Example of Peel TestD7747/D7747M 1114FIG. 5 Break Codes for Fillet Extrusion Weld Seams in Reinforced Geomembranes Tested for Seam Strength in Peel and Shear ModesD7747/D7747M 111510. Report10.1 The report sh
34、all include the following information:10.1.1 Type of test: shear or peel.10.1.2 Method A (1 in. specimen), or Method B (2 in.specimen).10.1.3 Individual location of break code for each specimen.10.1.4 Shear tests: Individual seam shear strength for eachspecimen and average seam shear strength for al
35、lspecimens inunits of N/mm or lbs/in.10.1.5 Peel tests: Individual seam peel strength for eachspecimen and average seam peel strength for all specimens inunits of N/mm or lbs/in., rate of extension.NOTE 2“Locus-of-Failure” (Fig. 1 and Fig. 5) include only some ofthe typically found seam configuratio
36、ns found in the industry. When thistest method is applied to seams bonded in configurations other than thoseidentified in Fig. 1 or Fig. 5, the users of this test method must agree onapplicable descriptions for modes of specimen rupture.10.1.6 If the specimen does not rupture, report this and themax
37、imum extension achieved during the test.11. Precision and Bias11.1 No statement can be made at this time concerningprecision or bias.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standar
38、d are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif
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40、h you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,Un
41、ited States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D7747/D7747M 1116
