1、Designation: D 6496 04aStandard Test Method forDetermining Average Bonding Peel Strength Between Topand Bottom Layers of Needle-Punched Geosynthetic ClayLiners1This standard is issued under the fixed designation D 6496; the number immediately following the designation indicates the year oforiginal a
2、doption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the laboratory determination ofthe average b
3、onding strength between the top and bottomlayers of a sample of a geosynthetic clay liner (GCL).1.2 The values in SI units are to be regarded as the standard.The values in inch-pound units are in parentheses for informa-tion.1.3 This standard does not purport to address all of thesafety concerns, if
4、 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 Specification for Tensile Testing Machines
5、for TextilesD 4439 Terminology for Geosynthetics3. Terminology3.1 Definitions:3.1.1 geosynthetic, na product manufactured wholly or inpart from polymeric material used with soil, rock, earth, orother geotechnical engineering related material as an integralpart of a project, structure, or system. D 4
6、4393.1.2 geosynthetic clay liner, na manufactured hydraulicbarrier consisting of clay bonded to a layer or layers ofgeosynthetic material(s). (Currently being balloted under D35Committee on Terminology)4. Summary of Test Method4.1 The top and bottom layers of a geosynthetic clay linerare gripped ind
7、ividually in tensile grips and pulled at a constantrate of extension by a tensile testing machine until the top andbottom layers of the specimen separate. The average bondingpeel strength of the test specimen can be calculated frommachine scales, dials, recording charts, or an interface com-puter.5.
8、 Significance and Use5.1 The bonding strength test for the top and bottom layersof the geosynthetic clay liner is intended to be an index test. Itis anticipated that the results of the test will be used to evaluatethe quality of the bonding process.6. Apparatus6.1 Tensile Testing MachineA constant r
9、ate of extension(CRE) type of testing machine described in Specification D76shall be used with a minimum precision measuring capabilityof 0.1 N/m (5.71 3 104lbf/in).6.2 ClampsThe clamps shall be a minimum 25 by 100mm (1 by 4 in.) and with appropriate clamping power toprevent slipping or crushing (da
10、mage).6.3 Die or Template, 100 by 200 mm (61 mm) (4 by 8 in.).6.4 Miscellaneous, knives, razor, and the like, as required.7. Test Specimen7.1 The sample received at the testing laboratory should bein satisfactory condition and representative of the productmanufactured or delivered to a site, or both
11、.7.2 The size of the die or template for cutting specimens is100 by 200 mm (4 by 8 in.).7.3 The loss of clay during the specimen cutting processshould have no bearing on the results of the test.7.4 A minimum of five test specimens should be cut fromthe laboratory sample such that they are representa
12、tive of theentire roll width. All specimens should be parallel to themachine direction.8. Conditioning8.1 The test specimen shall be tested as received.1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.04 on Geosyn-
13、thetic Clay Liners.Current edition approved Nov 1, 2004. Published December 2004. Originallyapproved in 1999. Last previous edition approved in 2003 as D 6496 04.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book
14、of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.9. Procedure9.1 Obtain SpecimensUsing the die, or template andrazor, and other neces
15、sary apparatus, carefully cut from thelaboratory sample five test specimens. The five specimensshould be randomly selected from locations on the sample, butshould be distributed across the sample. All specimens shouldbe cut parallel to the machine direction. Using a knife or razor,separate the top a
16、nd bottom layer of the GCL for the first 50 63mm(26 0.1 in.).9.2 Machine Set-Up ConditionsAdjust the distance be-tween the clamps at the start of the test to 50 6 3mm(26 0.1in.). Set the CRE at 300 mm/min. (12 in./min.).9.3 Insertion of Specimen in ClampsMount the specimencentrally in the clamps. Th
17、e specimen must be visuallyobserved above the clamp. The specimen length in the machinedirection must be parallel to the direction of application offorce.9.4 Measurement of Bonding Peel StrengthStart the ten-sile testing machine. This is considered the start of the peel testand represents zero grip
18、separation. Take readings of force andtime starting from 50 mm (2 in.) of grip separation until 250mm (10 in.) of grip separation. The average recorded peelingforce of the GCL over 200 mm (8 in.) of grip separation isrequired and will signify a complete test of the specimen. (SeeFig. 1).NOTE 1If sig
19、nificant elongation of the geotextile continues after 50mm (2 in.) additional grip peeling of the GCL, the recording intervalshould be adjusted. The recording interval should correspond to 200 mm(8 in.) of grip separation during the peeling of the GCL.9.4.1 Readings of force and time shall be taken
20、at aminimum rate of 20 readings per second.9.4.2 If a specimen slips in the jaws, or if for any reasonattributable to faulty operation the results fall significantlybelow the average for the set of specimens, discard the resultsand test another specimen. Continue until the required numberof readings
21、 have been taken.10. Calculation10.1 Bonding Peel StrengthCalculate the bond strength ofindividual specimens, that is, the average force to cause aspecimen to separate expressed in N (lbf.) of width, using thefollowing equation:af5 Favg/WS(1)where:af= bonding peel strength, N/m (lbf/in.) of width,Fa
22、vg= observed average force over a grip separation of 50mm (2 in.) to 250 mm (10 in.), N (lbf), andWS= specified specimen width, m (in.).10.2 Average Bonding Peel StrengthAverage the calcu-lated bonding peel strength of each specimen:aavg5 af11af211a15!/5 (2)where:afn= calculated average bond strengt
23、h for specimen,N/m (lbf/in.), andaavg= average bond strength of the GCL, N/m (lbf/in.)11. Report11.1 Report the following information on bonding peelstrength of GCLs:11.1.1 All specimen values and average bonding peelstrength/unit width to the nearest 0.1 N/m (5.71 3 10-4lbf/in),11.1.2 If requested,
24、 the standard deviation, coefficient ofvariation, or both,11.1.3 Sample identification (for example, sample no., rollno., or other traceable identifier),FIG. 1 Measurement of Bonding Peel StrengthD 6496 04a211.1.4 Type of GCL tested,11.1.5 Full scale force range used for testing,11.1.6 A statement o
25、f any departure from the suggestedtesting procedures so that the results can be evaluated and used,11.1.7 Note any cause or need for testing additional speci-mens due to rupture of the geotextile(s) during test, damage tospecimen from the grips, and so forth, and11.2 Identification of testing agency
26、, person performing thetest, date of test and client or project identification.12. Precision and Bias12.1 Inter-Laboratory Test ProgramAn inter-laboratorystudy of this test method was run in 2002/2003. Four differentgeosynthetic clay liner samples were distributed to ten labora-tories. Three sets of
27、 test results were generated for each sampleby each of the laboratories.12.2 Test ResultsThe precision information is given inTable 1. The results are presented for the average of thecoefficient of variation, CV %, for the four samples.12.3 BiasThe procedure in this test method for measuringthe bond
28、ing peel strength of the geosynthetic clay liner has nobias because the values of the bonding peel strength can bedefined in the terms of this test method.13. Keywords13.1 clay; bonding strength; geosynthetic; geosynthetic claylinerAPPENDIX(Nonmandatory Information)X1. Alternate MQC Test Method for
29、Peak Bonding Peel StrengthX1.1 This alternate test method can be used to determinethe peak bonding peel strength of the needle-punched geosyn-thetic clay liner. This alternative test method was developed toallow the manufacturer to test material with a tensiometer inclose proximity to the production
30、 line and/or in such a locationthat the ambient conditions could be harmful to the electronicdevice used to record the average bonding peel strength.X1.2 The manufacturer must document that the specifiedaverage bonding peel strength of the geosynthetic clay linerproduct will be met or exceeded by th
31、e minimum peak bondingstrength of the product.X1.3 The alternate test method shall follow Sections 1 thru9.3 exactly. The following sections shall be used as a replace-ment for the average bonding strength test method.X1.4 Measurement of Peak Bonding Peel StrengthX1.4.1 Start the tensile testing mac
32、hine.X1.4.2 Continue testing the specimen until complete peel ofthe GCL and record the maximum peel strength.X1.5 CalculationX1.5.1 Average Peak Peel StrengthAverage the recorded peak bonding strength of each speci-men:pavg5 pf11 pf21 1 pfn!/5where:pfn = recorded peak bonding strength for specimen,
33、N/m(lbf/in.), andpavg = average peak bonding strength of the GCL, N/m(lbf/in.)X1.6 ReportX1.6.1 Report the following information on peak bondingpeel strength of GCLs.X1.6.2 All specimen values and average peak bonding peelstrength/unit width to the nearest 0.1 N/m (5.71 x 10-4 lbf/in)X1.6.3 If reque
34、sted, the standard deviation, coefficient ofvariation, or both.X1.6.4 Sample identification (e.g. sample no., roll no., orother traceable identifier).X1.6.5 Type of GCL tested.X1.7 Full scale force range used for testing.X1.7.1 A statement of any departure from the suggestedtesting procedures so tha
35、t the results can be evaluated and used.X1.7.2 Note any cause or need for testing additional speci-mens due to rupture of the geotextile(s) during test, damage tospecimen from the grips, etc.X1.8 Identification of testing agency, person performing thetest, date of test and client or project identifi
36、cation.TABLE 1 Test ResultsStatistic ILS AverageWithin laboratory repeatability limit, CVSr, % 7Between laboratory reproducibility limit, CVSR, % 1195 % confidence limit within laboratory repeatability, CVr, % 1895 % confidence limit between laboratory reproducibility, CVR, % 32D 6496 04a3ASTM Inter
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40、dards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor 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).D 6496 04a4
