ASTM D 6766 : 2006 : REV A

1.1 This test method covers laboratory measurement of both flux and hydraulic conductivity (also referred to as coefficient of permeability) of geosynthetic clay liner (GCL) specimens permeated with chemical solutions and leachates utilizing a flexible wall permeameter. For test measurement of index hydraulic properties of geosynthetic clay liners, refer to Test Method D 5887.

1.2 This test method may be utilized with GCL specimens that have a hydraulic conductivity less than or equal to 1 10 ^-5 m/s (1 10^-3 cm/s).

1.3 This test method is applicable to GCL products having geotextile backing(s). It may not be applicable to GCL products with geomembrane backing(s).

1.4 This test method provides measurements of flux and hydraulic conductivity under a prescribed set of conditions, as an index test, that can be used for manufacturing quality control. The flux and hydraulic conductivity values determined using this test method under the prescribed set of conditions is not considered to be representative of the in-service conditions of GCLs. However, the test method allows the requester to establish a set of test conditions; thus, the test method also may be used to check performance or conformance, or both.

1.5 The values stated in SI units are to be regarded as the standard, unless other units are specifically given. By tradition in U.S. practice, hydraulic conductivity is reported in centimeters per second, although the common SI units for hydraulic conductivity are meters per second.

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 and health practices and determine the applicability of regulatory limitations prior to use.