ASTM D6496/D6496M-23a

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Designation: D6496/D6496M − 23 D6496/D6496M − 23a
Standard Test Method for
Determining Average Bonding Peel Strength Between Top
and Bottom Layers of Needle-Punched Geosynthetic Clay
Liners
This standard is issued under the fixed designation D6496/D6496M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the laboratory determination of the average bonding strength between the top and bottom layers of
a sample of a geosynthetic clay liner (GCL).
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the
two systems may result in nonconformance with the standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D76/D76M Specification for Tensile Testing Machines for Textiles
D123 Terminology Relating to Textiles
D4439 Terminology for Geosynthetics
D5889/D5889M Practice for Quality Control of Geosynthetic Clay Liners
D6072/D6072M Practice for Obtaining Samples of Geosynthetic Clay Liners
3. Terminology
3.1 Definitions:
3.1.1 geosynthetic clay liner, n—a manufactured hydraulic barrier consisting of clay bonded to a layer or layers of geosynthetic
material(s). D4439
This test method is under the jurisdiction of ASTM Committee D35 on Geosynthetics and is the direct responsibility of Subcommittee D35.04 on Geosynthetic Clay
Liners.
Current edition approved March 1, 2023April 15, 2023. Published March 2023May 2023. Originally approved in 1999. Last previous edition approved in 20202023 as
D6496/D6496M – 20.D6496/D6496M – 23. DOI: 10.1520/D6496_D6496M-23.10.1520/D6496_D6496M-23A.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
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D6496/D6496M − 23a
3.2 For terminology of other terms used in this test method, refer to Terminologies D123 and D4439.
4. Summary of Test Method
4.1 The top and bottom layers of a geosynthetic clay liner are gripped individually in tensile grips and pulled at a constant rate
of extension by a tensile testing machine until the top and bottom layers of the specimen separate. The average bonding peel
strength of the test specimen can be calculated from machine scales, dials, recording charts, or an interface computer.
5. Significance and Use
5.1 The bonding strength test for the top and bottom layers of the geosynthetic clay liner is intended to be an index test. It is
anticipated that the results of the test will be used to evaluate the quality of the bonding process.
6. Atmospheric Conditions
6.1 Atmospheric Conditions:
6.1.1 The atmospheric conditions of the laboratory determining average bonding peel strength between top and bottom layers of
needle-punched geosynthetic clay liners shall be: relative humidity between 50 to 70 % and a temperature of 21 6 2 °C [70 6
4 °F].
7. Apparatus
7.1 Tensile Testing Machine—A constant rate of extension (CRE) type of testing machine described in Specification D76/D76M
–4
shall be used with a minimum precision measuring capability of 0.1 N/m [5.71 × 10 lbf/in.].
7.1.1 Fixed Member—A fixed or essentially stationary member carrying one clamp.
7.1.2 Movable Member—A movable member carrying a second clamp.
7.2 Clamps—The clamps shall be a minimum 25 by 100 mm [1 by 4 in.] and with appropriate clamping power to prevent slipping
or crushing (damage). Clamps for holding the test specimen between the fixed member and the movable member of the test
apparatus can be either a fixed or self-aligning type.
7.2.1 Fixed clamps are rigidly attached to the fixed and movable members of the test apparatus. Extreme care should be taken
when this type of clamp is used to ensure that the test specimen is inserted and clamped so that the long axis of the test specimen
coincides with the direction of pull through the centerline of the clamp assembly.
7.2.2 Self-aligning clamps are attached to the fixed and movable members of the test apparatus. This type of clamp assembly is
such that they will move freely into alignment as soon as any load is applied as long as the long axis of the test specimen will
coincide with the direction of the applied pull through the centerline of the clamp assembly. The specimens should be aligned as
perfectly as possible with the direction of pull so that no rotary motion will occur in the clamps thereby inducing slippage; there
is a limit to the amount of misalignment self-aligning clamps will accommodate.
7.3 Die or Template, 100 by 200 mm (61 mm) [4 by 8 in.].
7.4 Miscellaneous—Knives, razor, and the like, as required.
8. Sampling, Test Specimens, and Test Units
8.1 Lot Sample—For the lot sample, take rolls of GCLs as directed in an applicable material specification, Practice
D5889/D5889M, or as agreed upon between the purchaser and the supplier.
8.2 Laboratory Sample—For the laboratory sample, sample shall be taken in accordance with Practice D6072/D6072M. The
sample received at the testing laboratory should be in satisfactory condition and representative of the product manufactured or
delivered to a site, or both.
D6496/D6496M − 23a
8.3 Test Specimens—A minimum of five test specimens shall be taken in the machine direction from each swatch in the laboratory
sample. Take specimens from the laboratory sample, with those for the measurement of the machine direction tensile properties
from different positions across the GCL width. No specimens shall be taken within 10 cm [4 in.] of the selvage or edge of the GCL.
8.4 The size of the die or template for cutting specimens is 100 by 200 mm (mini
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