1、Designation: D 6392 08Standard Test Method forDetermining the Integrity of Nonreinforced GeomembraneSeams Produced Using Thermo-Fusion Methods1This standard is issued under the fixed designation D 6392; the number immediately following the designation indicates the year oforiginal adoption or, in th
2、e 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 controland quality assurance tests used
3、 to determine the integrity ofgeomembrane seams produced by thermo-fusion methods.This test method presents the procedures used for determiningthe quality of nonbituminous bonded seams subjected to bothpeel and shear tests. These test procedures are intended fornonreinforced geomembranes only.1.2 Th
4、e types of thermal field seaming techniques used toconstruct geomembrane seams include the following.1.2.1 Hot AirThis technique introduces high-temperatureair or gas between two geomembrane surfaces to facilitatemelting. Pressure is applied to the top or bottom geomembrane,forcing together the two
5、surfaces to form a continuous bond.1.2.2 Hot Wedge (or Knife)This technique melts the twogeomembrane surfaces to be seamed by running a hot metalwedge between them. Pressure is applied to the top or bottomgeomembrane, or both, to form a continuous bond. Someseams of this kind are made with dual bond
6、 tracks separated bya nonbonded gap. These seams are sometimes referred to asdual hot wedge seams 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.1.3 The types of m
7、aterials covered by this test methodinclude the following.1.3.1 Very Low Density Polyethylene (VLDPE).1.3.2 Linear Low Density Polyethylene (LLDPE).1.3.3 Very Flexible Polyethylene (VFPE).1.3.4 Linear Medium Density Polyethylene (LMDPE).1.3.5 High Density Polyethylene (HDPE).1.3.6 Polyvinyl Chloride
8、 (PVC).1.3.7 Flexible Polypropylene (fPP).NOTE 1The polyethylene identifiers presented in 1.3.1-1.3.5 describethe types of materials typically tested using this test method. These areindustry accepted trade descriptions and are not technical materialclassifications based upon material density.1.4 Th
9、is 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 Documen
10、ts2.1 ASTM Standards:2D 638 Test Method for Tensile Properties of PlasticsD 4439 Terminology for GeosyntheticsD 5199 Test Method for Measuring the Nominal Thicknessof GeosyntheticsD 5994 Test Method for Measuring Core Thickness ofTextured Geomembrane2.2 EPA Standards:EPA/600/2-88/052 Lining of Waste
11、 Containment and OtherContainment Facilities;Appendix N, Locus of break codesfor various types of FML seams33. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 geomembrane, nessentially impermeable geosyn-thetic composed of one or more synthetic sheets.3.1.2 quality assurance, nal
12、l planned and systematic ac-tions necessary to provide adequate confidence that an item ora facility will perform satisfactorily in service.3.1.3 quality control, nthe operational techniques and theactivities, which sustain a quality of material, product, system,or service that will satisfy given ne
13、eds; also the use of suchtechniques and activities.4. Significance and Use4.1 The use of geomembranes as barrier materials to restrictliquid migration from one location to another in soil and rockhas created a need for a standard test method to evaluate thequality of geomembrane seams produced by th
14、ermo-fusionmethods. In the case of geomembranes, it has become evident1This 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 July 1, 2008. Published July 2008. Originally appr
15、ovedin 1999. Last previous edition approved in 2006 as D 639299(2006).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
16、 website.3Available from the Superintendent of Documents, US Government PrintingOffice, Washington, DC 20402.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.that geomembrane seams can exhibit separation in the fieldunder certain cond
17、itions. Although this is an index type testmethod used for quality assurance and quality control pur-poses, it is also intended to provide the quality assuranceengineer with sufficient seam peel and shear data to evaluateseam quality. Recording and reporting data, such as separationthat occurs durin
18、g the peel test and elongation during the sheartest, will allow the quality assurance engineer to take measuresnecessary to ensure the repair of inferior seams during facilityconstruction, and therefore, minimize the potential for seamseparation in service.5. Apparatus5.1 Tensile instrumentation sha
19、ll meet the requirementsoutlined in Test Method D 638.5.2 Grip FacesGrip faces shall be 25 mm (1 in.) wide anda minimum of 25 mm (1 in.) in length. Smooth rubber, fineserrated or coarse serrated grip faces have all been found to besuitable for testing geomembrane seams.6. Sample and Specimen Prepara
20、tion6.1 Seam SamplesCut a portion of the fabricated seamsample from the installed liner in accordance with the projectspecifications. It is recommended that the cutout sample be 0.3m (1 ft) wide and 0.45 m (1.5 ft) in length with the seamcentered in the middle.6.2 Specimen PreparationTen specimens s
21、hall be cutfrom the sample submittal. The specimens shall be die cutusing a 25 mm (nominal 1 in.) wide by a minimum of 150 mm(nominal 6 in.) long die. Specimens that will be subjected topeel and shear tests shall be selected alternately from thesample and labeled as shown in Fig. 1. Specimens shall
22、be cutsuch that the seam is perpendicular to the longer dimension ofthe strip specimen.6.3 ConditioningSamples should be conditioned for 40 hin a standard laboratory environment that conforms to therequirements for testing geosynthetics as stated in TerminologyD 4439. Long sample conditioning times
23、typically are notpossible for most applications that require seam testing. Priorto testing, samples should be conditioned for a minimum of 1hat236 2C and a relative humidity between 50 and 70 %.7. Destructive Test Methods7.1 Peel TestingSubject five specimens to the 90 “T-Peel” test (see Fig. 2). If
24、 the tested sample is a dual hot wedgeseam, five specimens must be examined for each external trackof the seam. Maintaining the specimen in a horizontal positionthroughout the test is not required. Fully grip the test specimenacross the width of the specimen. Grip the peel specimen bysecuring grips
25、25 mm (1 in.) on each side of the start of theseam bond, a constant machine cross head speed of 50 mm (2in.)/min for HDPE, LMDPE, and PVC, 500 mm (20 in.)/minfor LLDPE, VLDPE, VFPE, and fPP. The test is completewhen the specimen ruptures.7.2 Shear TestingSubject five specimens to the shear test(see
26、Fig. 2). Fully support the test specimen within the gripsacross the width of the specimen. Secure the grips 25 mm (1in.) on each side of the start of the seam bond, a constantmachine cross head speed of 50 mm (2 in.)/min for LMDPEand HDPE, 500 mm (20 in.)/min for fPP, LLDPE, VFPE,VLDPE, and PVC. The
27、 test is complete for HDPE and LMDPEonce the specimen has elongated 50 %. PVC, fPP, LLDPE,VFPE and VLDPE geomembranes should be tested to rupture.NOTE 2Both peel and shear tests for fPP, LLDPE, VLDPE, and PVCgeomembranes have been tested routinely at both 2 and 20 in./min. Whenconducting seam peel o
28、r shear testing for quality control, or qualityassurance purposes, or both, it may be necessary to select the manufac-turers recommended testing speed. In the absence of explicit testingspeed requirements, follow those recommended in 7.1 and 7.2.8. Calculations and Observations8.1 Estimate of Seam P
29、eel SeparationVisually estimatethe seam separation demonstrated prior to rupture for peelspecimens. The estimate shall be based upon the proportion ofthe area of the separated bond, to the area of original bondingto the nearest 5%. However, if at any point across the width ofFIG. 1 Seam SampleD63920
30、82the peel specimen, seam separation continues to the other sideof the bonded area, the estimate of seam peel separation shallbe 100 % regardless of the proportion of the area of theseparated bond to the area of the original bonding.NOTE 3During the thermo-fusion welding process, some of themelted p
31、olymer may be shifted to the outside of the weld during thepressing of the geomembrane panels together. This melted polymer issometimes called “squeeze-out” or “bleed out” and is not considered partof the bond. Care must be exercised during estimation of the seam peelseparation to segregate the sque
32、eze or bleed out area from the peeled bondarea. The reported peel separation shall include the peeled bond area only.8.2 Rupture Mode SelectionDetermine the locus of breakfor both the peel and shear specimens as shown in Figs. 3 and4. The locus of break for shear specimens that do not ruptureprior t
33、o test end (50 % elongation) shall be interpreted asoccurring in the membrane that exhibits yielding.8.3 Shear Percent ElongationCalculate the percent elon-gation on shear specimens according to Eq 1. Divide theextension at test end by the original gage length of 25 mm andmultiply by 100.Elongation
34、5 ELL03 100 (1)where:L = extension at test end, andL0= original gauge length.NOTE 4The intent of measuring elongation using this test method isto identify relatively large reductions in typical break elongation values ofseam samples. Length is defined as the distance from one grip to the seamedge. U
35、sing this definition implies that all strain experienced by thespecimen during the shear test occurs on one side of the seam. Of coursethis assumption is inaccurate, since some strain will occur on each side ofthe seam, and in the seam area itself; however, it is difficult to make anaccurate measure
36、ment of the strain distribution which occurs in thespecimen during testing. Further, it is not critical to know the exactlocation of all the strain which occurs during testing but rather to simplyidentify when significant reductions in elongation (when compared withthe typical elongation of a new ma
37、terial) have occurred.9. Report9.1 The report shall include the following information.9.1.1 Report the individual peel and shear specimen maxi-mum unit tension values in N/mm of width (lb/in.).NOTE 5If requested, report the maximum peel or shear stress. Thiscalculation will require an accurate measu
38、rement of thickness for eachspecimen. These measurements should be made in accordance with TestMethod D 5199 for smooth geomembranes and Test Method D 5994 fortextured geomembranes.9.1.2 Report the cross head speed used during peel andshear testing.9.1.3 Report the average of the individual peel and
39、 shearsample values recorded.9.1.4 If the peel or shear specimen does not rupture, reportthe elongation at the maximum cross-head travel limitation. Ifthe gage length is reduced to less than 25 mm (1 in.), this mustbe noted in the report.9.1.5 Report the mode of specimen rupture for peel andshear sp
40、ecimens according to Fig. 3 or Fig. 4.FIG. 2 Shear and T-Peel SpecimensD6392083NOTE 6“Locus-of-Failure” (Figs. 3 and 4) include only some of thetypically found seam configurations found in the industry. When this testmethod is applied to seams bonded in configurations other than thoseidentified in F
41、ig. 3 or Fig. 4, the users of this test method must agree onapplicable descriptions for modes of specimen rupture.10. Precision and Bias10.1 No statement can be made at this time concerningprecision or bias.FIG. 3 Locus-of-Break Codes for Dual Hot Wedge Seams in Unreinforced Geomembranes Tested for
42、Seam Strength in Shear and PeelModesD6392084FIG. 4 Locus-of-Break Codes for Fillet Extrusion Weld Seams in Unreinforced Geomembranes Tested for Seam Strength in Shear andPeel ModesD6392085ASTM International takes no position respecting the validity of any patent rights asserted in connection with an
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46、Drive, PO Box C700, West Conshohocken, PA 19428-2959,United 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).D6392086
