1、Designation: D7272 06 (Reapproved 2011)Standard Test Method forDetermining the Integrity of Seams Used in JoiningGeomembranes by Pre-manufactured Taped Methods1This standard is issued under the fixed designation D7272; the number immediately following the designation indicates the year oforiginal ad
2、option 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 controland/or quality a
3、ssurance tests to determine the integrity ofseams produced using taped seaming methods. This testmethod presents the procedures used for determining thequality of taped seams subjected to both peel and shear tests.These test procedures are intended for non-reinforced andreinforced geomembranes.1.2 T
4、he types of tape seaming techniques used to constructgeomembrane seams include the following.1.2.1 Inseam TapeThis technique requires the membraneto be overlapped a minimum distance. The top sheet is foldedback and both the bottom sheet and the top sheet are primedwith an adhesive primer. The primer
5、 is allowed to flash-off. Thetape adhesive is applied to the bottom sheet so that a minimumof the tape will extend out from under the top sheet when laidover the tape. The top sheet is allowed to lay flat over the tapeand the release paper is removed by pulling it at a 45 to 90degree angle, keeping
6、the release paper flat to the surface of thebottom sheet. The seam area is then rolled with a siliconesleeved roller.1.2.2 Cover Strip TapeThis technique requires the mem-brane to be overlapped a minimum distance.An area either sideof the seam edge is primed. The primer is allowed to flash-off.The c
7、over strip is applied with the adhesive side down centeredover the top sheet edge while removing the release paper as itproceeds along centered over the edge of the top sheet. Thecover strip is then rolled with a silicone sleeved roller.1.3 For nondestructive test methods, see Practice D4437.1.4 Thi
8、s test method is applicable for seaming processesthat use tape adhesive as a seaming mechanism.1.5 Subsequent decisions as to seam acceptance criteria aremade according to the site-specific contract plans, specifica-tions, and contractor quality control/contractor quality assur-ance (CQC/CQA) docume
9、nts.1.6 In case of a material specific test method, this testmethod shall take precedence.1.7 Hazardous MaterialsAlways consult the proper ma-terial safety data sheets for any hazardous material used for theproper ventilation and protection. The use of the oven in thesetest methods, in this practice
10、, may accelerate fume productionfrom the test specimen.1.8 The values stated in both inch-pound and SI units are tobe regarded separately as the standard. Values in parenthesesare for information only.1.9 This standard does not purport to address all of thesafety concerns, if any, associated with it
11、s 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:2D413 Test Methods for Rubber PropertyAdhesion toFlexible SubstrateD638
12、Test Method for Tensile Properties of PlasticsD653 Terminology Relating to Soil, Rock, and ContainedFluidsD882 Test Method for Tensile Properties of Thin PlasticSheetingD4437 Practice for Non-destructive Testing (NDT) for De-termining the Integrity of Seams Used in Joining FlexiblePolymeric Sheet Ge
13、omembranesD4439 Terminology for GeosyntheticsD5199 Test Method for Measuring the Nominal Thicknessof GeosyntheticsD5994 Test Method for Measuring Core Thickness ofTextured Geomembranes3. Terminology3.1 DefinitionsFor definitions of other geosynthetic termsused in this method, refer to Terminology D4
14、439. For defini-tions of soil terms, refer to Terminology D653.1This 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 June 1, 2011. Published July 2011. Originally approved200
15、6. Last previous version approved 2006 as D727206.DOI: 10.1520/D7272-06R11.2For 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
16、 ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2 Definitions of Terms Specific to This Standard:3.2.1 tape adhesive, nsolid strip of prefabricated or manu-factured adhesive factory laminated to a release paper used t
17、ojoin two polymer sheets.3.2.2 tape adhesive seam, nadhesive-based tape placedbetween two polymer sheet materials forming a surface bond.3.2.3 cover strip adhesive, nsolid strip of prefabricated ormanufactured adhesive factory laminated to layer of polymersheet material factory laminated to a releas
18、e paper used to jointwo polymer sheets.3.2.4 cover strip adhesive seam, nadhesive-based lami-nated tape placed over two overlapping polymer sheet materi-als forming a surface bond.4. Significance and Use4.1 SignificanceWith the increased use of geomembranesas a barrier material to restrict liquid mi
19、gration from onelocation to another, a need has been created for a standard testmethod to evaluate the quality of geomembrane seams pro-duced by tape methods. In the case of geomembranes, it hasbecome evident that geomembrane seams can exhibit separa-tion in the field under certain conditions. This
20、is an index typetest method used for quality assurance and quality controlpurposes, it is also intended to provide the quality engineerwith sufficient seam peel and shear data to evaluate seamquality.4.2 UseRecording and reporting data such as separationthat occurs during the peel test and elongatio
21、n during the sheartest, will allow the quality assurance engineer to take measuresnecessary to ensure the repair of inferior seams during con-struction, and therefore, minimize the potential for seamseparation while in service. The acceptable value of adhesionmeasured will, of course, vary from prod
22、uct to product as aresult of different formulations and types of products. How-ever, once a product is established, minimum values ofseparation force can be determined and agreed to by producerand consumer and both can monitor the installation to assuremaintenance of the agreed-upon minimum value.5.
23、 Apparatus5.1 Tensile instrumentation shall meet the requirementsoutlined in Test Method D638 or D882.5.2 A testing machine of the constant-rate-of-cross headmovement type comprising essentially of the following:5.2.1 Fixed MemberA fixed or essentially stationarymember carrying one grip.5.2.2 Movabl
24、e MemberA movable member carrying asecond grip.5.2.3 GripsGrips for holding the test specimen betweenthe fixed member and the movable member and minimizesboth slippage and uneven stress distribution. The grips shall beself-aligning so that they shall be attached to the fixed andmovable member, respe
25、ctively, in such a manner that they willmove freely into alignment as soon as any load is applied, sothat the long axis of the test specimen will coincide with thedirection of the applied pull through the center line of the gripassembly. Grip faces shall be 25 mm (1 in.) wide and aminimum of 25 mm (
26、1 in.) in length. Smooth surfaces, fineserrated or coarse serrated grip faces, use the grips that have allbeen found to be suitable for testing, depending on type ofgeomembrane seams that are being tested.NOTE 1Grips lined with thin rubber, crocus-cloth or pressure sensi-tive tape as well as file-fa
27、ced or serrated grips have been successfully usedfor many materials. The choice of grip surface will depend on the materialtested, thickness, etc.5.2.4 Drive MechanismA drive mechanism for impartingto the movable member in uniform, controlled velocity withrespect to the stationary member. Unless oth
28、erwise specified inthe material specification, the mechanism shall be capable ofand adjusted so that the movable member shall have a uniformspeed of 50 mm/min, (2 in./min), 300 mm/min (12 in./min),and 500 mm/min (20 in./min).5.2.5 Load IndicatorA suitable load-indicating mecha-nism capable of showin
29、g the total tensile load carried by thetest specimen when held by the grips. This mechanism shall beessentially free of inertia lag at the specified rate of testing andshall indicate the load with an accuracy of 61 % of theindicated value or better.5.2.6 Extension Indicator (Extensometer) (If Employ
30、ed)Asuitable instrument shall be used for determining the distancebetween two designated points within the gage length of thetest specimen as the specimen is stretched and shall conform torequirements specified in Test Method D638.6. Sampling and Specimen Preparation6.1 Trial Seam SampleA representa
31、tive seam from eachseaming crew, fabricated from the same sheet material, andusing the seaming methods as those recommended by thegeomembrane fabricator manufacturer, shall be used for thismethod.6.1.1 Destructive Seam SampleAlternatively, cut a por-tion of the fabricated seam from the installed lin
32、er or a dailytest seam sample in accordance with the project specifications.It is recommended that the cutout sample be 0.3 m (1 ft) wideand 0.45 m (1.5 ft) in length with the seam centered in themiddle of the seam.6.1.2 Specimen PreparationFive specimens shall be cutfrom the submittal sample for ea
33、ch the Peel and Shear test. Thespecimens for the Peel test shall be cut using a calibrated die,25 6 3 mm (nominal 1 6 0.125 in.) wide by 150 6 3mm(nominal 6 6 0.125 in.) long die. The Specimens for the Sheartest shall be die cut using a calibrated die, 25 6 3 mm (nominal1 6 0.125 in.) wide by 2 inch
34、es greater than the width of theseam. Specimens shall be such that the die is centered over thesample seam, perpendicular to the centerline of the seam. Peeland shear specimens shall be cut as shown in Fig. 1.6.1.3 ConditioningSamples should be conditioned for 24hours in a standard laboratory enviro
35、nment that conforms tothe requirements for testing geosynthetics as stated in Termi-nology D4439. Long sample conditioning times typically arenot possible for most applications that require daily seamtesting. Prior to testing, samples should be conditioned for aminimum of1hat216 2C and a relative hu
36、midity between50 and 70 %.NOTE 2Some adhesives may build up on the die. Dies need to beinspected and cleaned periodically. A non-reactive release agent may beused on the die to reduce adhesive buildup, but type and frequency of useD7272 06 (2011)2must be documented in test report.7. Destructive Test
37、 Methods7.1 Peel TestingSubject five specimens to the 180 “T-Peel” test (see Fig. 2). Maintaining the specimen in a horizontalposition throughout the test is not required. Fully grip the testspecimen across the width of the specimen. Grip the peelspecimen by securing grips 13 mm (12 in.) on each sid
38、e of thestart of the seam bond. Apply a constant machine cross headspeed of 500 mm (20 in.)/ min. The test is complete when thespecimen ruptures. The seam samples shall be tested inaccordance with Test Methods D413 MethodA. The individualspecimens shall be 25 6 3mm(16 0.125 in.) wide and shallbe cut
39、 with a standard calibrated die. The die shall be centeredover the sample seam perpendicular to the centerline of theseam. The grips shall be positioned 25 mm (1 in.) apart with nomore than 13.5 mm (0.5 in.) on either side of the start of theseam bond (seam bond centered between the grip edges). The
40、grip surfaces shall be acceptable for the testing of the specifictest material to prevent pullout. Grips shall be self aligning sothat the axis of the test specimen will coincide with thedirection of the applied load through the centerline of the gripassembly. The samples shall be inserted so that t
41、hey arecentered and under no initial stress and fully supported acrossthe width of the seam. The seam overlap shall be as fabricated.The specimens shall be pulled to rupture.7.2 Shear TestingSubject five specimens to the shear test(see Fig. 2). Fully support the test specimen within the gripsacross
42、the width of the specimen. The seam samples shall betested in accordance with Test Method D882. The samplesshall be 25 mm (1 in.) wide by 50 mm (2 in.) greater that thewidth of the seam. The cut shall be centered over the seam,perpendicular to the centerline of the seam. Grip separationshall be 50 m
43、m (2 in.) plus the width of the seam. The samplesshall be tested at a cross head speed of 500 mm (20 in.)/min.The grip surfaces shall be acceptable for the testing of thespecific material to prevent pullout. Grips shall be self aligningso that the axis of the test specimen will coincide with thedire
44、ction of the applied load through the centerline of the gripassembly. The seam overlap shall be as fabricated. Fullysupport the test specimen within the grips across the width ofthe specimen. The specimens shall be pulled to rupture or aspecified percent strain (that is, 50 %, 100 %, 200 %).NOTE 3Bo
45、th peel and shear tests for fPP, LLDPE, VLDPE, EPDM,and PVC geomembranes have been tested routinely at both 2 and 20in./min. When conducting seam peel or shear testing for quality control, orquality assurance purposes, or both, it may be necessary to select themanufacturers recommended testing speed
46、. In the absence of explicitFIG. 1 Seam SampleD7272 06 (2011)3testing speed requirements, follow those recommended in 7.1 and 7.2.8. Calculations and Observations8.1 Estimate of Seam Peel SeparationVisually estimatethe seam separation demonstrated prior to rupture for peelspecimens. The estimate sha
47、ll be based upon the proportion oflinear length of separated bond in the direction of the test, tothe length of original bonding to the nearest 25 %.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 spec
48、imens that do not ruptureprior to test end shall be interpreted as occurring in themembrane 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 1
49、00.Elongation 5 L/L03 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. Using 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
