ASTM D5887/D5887M-20

5.1 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.

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

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

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

5.5 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. Refer to Appendix X2 for calculation of hydraulic conductivity.

5.6 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 is not applicable to GCL products with geomembrane backing(s), geofilm backing(s), or polymer coating 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 either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.

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

1.6 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.