Needle-punched geosynthetic clay liner (GCL) manufacturers will benefit from ASTM D 6496, Standard Test Method for Determining Average Bonding Peel Strength Between the Top and Bottom Layers of Needle-Punched Geosynthetic Clay Liners.

The test method is now available to assist in certification of GCLs used to contain waste and water. Ultimately, data obtained with D 6496 can lead to the elevation of water and waste containment safety by assessing its internal stability.

“This standard will initially benefit the needle-punched geosynthetic clay liner (GCL) manufacturers in their production of quality control and certification documents,” explains Robert Mackey, P.E., senior design engineer, S2L, Inc., Maitland, Fla., who chairs the ASTM GCL subcommittee and task group. “Future uses include quality assurance testing by the GCL users and correlation with ASTM D 6243, Standard Test Method for Determining the Internal and Interface Shear Resistance of Geosynthetic Clay Liner by Direct Shear Method.

“ASTM D 6243 is a difficult test that requires several days to get the results for internal shear strength of the GCL. Researchers have attempted to correlate peel strength of the GCL to the internal shear strength. However, there has not been a standardized test method for peel strength or internal shear strength until recently. This test method will allow the research to continue and develop a standardized database of results. The end outcome will allow the design engineer and/or user to specify GCLs which meet ‘design stability requirements’ without the continuous need of a difficult test and time requirement.”

The test was developed by the combined effort of representatives from the manufacturers, geotechnical testing laboratories, geotechnical researchers, government agencies, and design engineers in a task group of ASTM Subcommittee D35.04 on Geosynthetic Clay Liners, under Committee D35 on Geosynthetics.

ASTM standards are available by calling Customer Service (610/832-9585), or through the Web site.

For further technical information, contact Robert E. Mackey, P.E., S2L, Inc., 529 Versailles Dr., Suite 103, Maitland, FL 32751 (407/475-9163). Committee D35 meets June 21-23 in Toronto, Ontario, Canada. For meeting or membership details, contact manager Pat Picariello, ASTM (610/832-9720). //

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