1、Designation: D6392 12Standard Test Method forDetermining the Integrity of Nonreinforced GeomembraneSeams Produced Using Thermo-Fusion Methods1This standard is issued under the fixed designation D6392; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、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 t
3、o 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 The
4、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 su
5、rfaces 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 t
6、racks 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 mat
7、erials 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 This
9、 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 Documents
10、2.1 ASTM Standards:2D638 Test Method for Tensile Properties of PlasticsD4439 Terminology for GeosyntheticsD5199 Test Method for Measuring the Nominal Thicknessof GeosyntheticsD5994 Test Method for Measuring Core Thickness of Tex-tured Geomembranes2.2 EPA Standards:EPA/600/2-88/052 Lining of Waste Co
11、ntainment 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, nall p
12、lanned 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 needs
13、; 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 rock1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct respons
14、ibility of Subcommittee D35.10 on Geomem-branes.Current edition approved July 1, 2012. Published September 2012. Originallyapproved in 1999. Last previous edition approved in 2008 as D639208. DOI:10.1520/D6392-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Cu
15、stomer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from the Superintendent of Documents, US Government PrintingOffice, Washington, DC 20402.Copyright ASTM International, 100 Barr Harbor Dr
16、ive, PO Box C700, West Conshohocken, PA 19428-2959. United States1has created a need for a standard test method to evaluate thequality of geomembrane seams produced by thermo-fusionmethods. In the case of geomembranes, it has become evidentthat geomembrane seams can exhibit separation in the fieldun
17、der certain conditions. Although this is an index type testmethod used for quality assurance and quality controlpurposes, 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 separationtha
18、t occurs during 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 instr
19、umentation shall meet the requirementsoutlined in Test Method D638.5.2 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 Spe
20、cimen Preparation6.1 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 PreparationTe
21、n specimens shall 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. Spe
22、cimens shall 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 TerminologyD4439. Long sample conditi
23、oning times 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
24、 Fig. 2). If 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 bysec
25、uring grips 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 she
26、ar test(see 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,
27、and PVC. The 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
28、 seam peel or shear testing for quality control, or qualityFIG. 1 Seam SampleD6392 122assurance 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
29、 and Observations8.1 Estimate of Seam Peel 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 acro
30、ss the width ofthe 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.8.1.1 In cases of dispute, the peel separation estimat
31、e maybe documented via direct measure.8.1.2 Procedure: Determine the total area of bonded area forwhich the peel test was performed using calipers to spanmeasure the maximum length of the bond being careful notinclude squeeze-out or tack welded areas. Verify the seamwidth of one inch.8.1.3 Assign ap
32、propriate geometric shapes to approximatethe area of each separated portion of the peeled zone.8.1.4 Place the peeled specimen flat against the surface of aflat bed scanner set at 100% scale.8.1.5 Produce a record of the peeled area for easier shapeassignment and peeled area determination. Care shou
33、ld betaken to assure intimate contact between the peeled specimenand the scanner surface so as to preserve dimensions.8.1.6 Using the same calipers, record the dimensions ofeach peeled area.8.1.7 Using the recorded dimensions, calculate percent peelas follows and round to the nearest 5%.S 5 100* AAo
34、(1)where:S = Percent peel separationA = Area of peel separation measuredAo= Area of original bonded region (not including trackweld, tack weld, or squeeze-out, see Note 3 and Note 4)NOTE 3During the thermo-fusion welding process, some of themelted polymer may be shifted to the outside of the weld du
35、ring 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 squeeze or bleed out area from the peeled bondarea. The
36、 reported peel separation shall include the peeled bond area only.NOTE 4The exact area of original bond (Ao) for use in Equation 1 forpeel separation is sometimes ambiguous. For most cases, the area of peelmeasured for thermo fusion extrusion seams is that area defined by thewidth of the specimen mu
37、ltiplied by the distance between the terminationof the top geomembrane and the outermost edge of the extrusion weldalong the bottom geomembrane. To be counted as part of the weld, theextruded material must be at least as thick as the nominal thickness of thegeomembrane.8.2 Rupture Mode SelectionDete
38、rmine 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 to test end (50 % elongation) shall be interpreted asoccurring in the membrane that exhibits yielding.FIG. 2 Shear and T-Peel SpecimensD6392 1238.3
39、Shear Percent ElongationCalculate the percent elon-gation on shear specimens according to Eq 2. Divide theextension at test end by the original gage length of 25 mm andmultiply by 100.ElongationE! 5LL03100 (2)where:L = extension at test end, andL0= original gauge length.NOTE 5The intent of measuring
40、 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. Using this definition implies that all strain experienced by thespecimen during the shear test occurs on on
41、e 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 measurement of the strain distribution which occurs in thespecimen during testing. Further, it is not critical to
42、 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 material) have occurred.9. Report9.1 The report shall include the following information.9.1.1 Report the ind
43、ividual peel and shear specimen maxi-mum unit tension values in N/mm of width (lb/in.).NOTE 6If requested, report the maximum peel or shear stress. Thiscalculation will require an accurate measurement of thickness for eachspecimen. These measurements should be made in accordance with TestMethod D519
44、9 for smooth geomembranes and Test Method D5994 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 shearsample values recorded.9.1.4 If the peel or shear specimen does not rupture, reportthe elongation at t
45、he 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 specimens according to Fig. 3 or Fig. 4.FIG. 3 Locus-of-Break Codes for Dual Hot Wedge Seams in Unreinforced G
46、eomembranes Tested for Seam Strength in Shear and PeelModesD6392 124NOTE 7“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 Fig. 3 or Fi
47、g. 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. 4 Locus-of-Break Codes for Fillet Extrusion Weld Seams in Unreinforced Geomembranes Tested for Seam
48、 Strength in Shear andPeel ModesD6392 125ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and th
49、e 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 not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1