This test method yields the flux of water through a saturated GCL specimen that is consolidated, hydrated, and permeated under a prescribed set of conditions.

This test method can be performed to determine if the flux of a GCL specimen exceeds the maximum value stated by the manufacturer.

This test method can be used to determine the variation in flux within a sample of GCL by testing a number of different specimens.

This test method does not provide a flux value to be used directly in design calculations.

Note 1—Flux for in-service conditions depends on a number of factors, including confining pressure, type of hydration fluid, degree of hydration, degree of saturation, type of permeating fluid, and hydraulic gradient. Correlation between flux values obtained with this test method and flux through GCLs subjected to in-service conditions has not been fully investigated.

This test method does not provide a value of hydraulic conductivity. Although hydraulic conductivity can be determined in a manner similar to the method described in this test method, the thickness of the specimen is needed to calculate hydraulic conductivity. This test method does not include procedures for measuring the thickness of the GCL nor of the clay component within the GCL.

The apparatus used in this test method is commonly used to determine the hydraulic conductivity of soil specimens. However, flux values measured in this test are typically much lower than those commonly measured for most natural soils. It is essential that the leakage rate of the apparatus used in this test be less than 10 % of the flux.

1.1 This test method covers an index test that covers laboratory measurement of flux through saturated geosynthetic clay liner (GCL) specimens using a flexible wall permeameter.

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

1.3 This test method provides a measurement of flux under a prescribed set of conditions that can be used for manufacturing quality control. The test method can also be used to check conformance. The flux value determined using this test method is not considered to be representative of the in-service flux of GCLs.

1.4 The values stated in SI units are to be regarded as the standard, unless other units are specifically given.

1.5 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.