ASTM D5890

Swell Index of Clay Mineral Component of Geosynthetic Clay Liners

Applicability: ASTM D5890 applies to determining the swell index of clay mineral (primarily bentonite) used as the functional component of geosynthetic clay liners (GCLs). It is applicable to powdered and granular clay minerals tested in reagent water, but is not applicable to clays containing polymers. It is adapted from the United States Pharmacopeia (USP-NF-XVII) test method for bentonite.

Purpose: ASTM D5890 provides an index method for evaluating the swelling properties of clay mineral in reagent water to estimate its suitability for use in geosynthetic clay liners. Its purpose is to characterize a key performance-related property of the clay mineral—its capacity to swell and thereby reduce hydraulic conductivity—which is critical for assessing GCL effectiveness in containing industrial waste, ground water, or landfill leachate.