Influence of Solution Characteristics on Swelling and Hydraulic Performance of Geosynthetic Clay Liner

Abstract:

The influence of solutions with different valence and concentration of cation and different hydrated ionic radiuses on swelling characteristics and hydraulic properties of geosynthetic clay liner (GCL) were explored using free swell tests and hydraulic conductivity tests. It is found that cation valence, concentration and hydrated ionic radius all have impacts on swelling and hydraulic performance of GCL. Test results indicate that the free swell of bentonite decreases,while hydraulic conductivity of GCL gradually increases with the increasing of cation valence and concentration; monovalent cation concentration has greater influence on GCL swell amount and hydraulic conductivity than that of the concentration of divalent or trivalent cations; the free swell amount of bentonite in monovalent cation solutions increases with the increasing of hydrated ionic radius, while hydraulic conductivity of GCL decreases with the hydrated ionic radius. Finally, the mechanical analyses on GCL swelling and hydraulic performance are made based on the related theory and experimental results.

Key words:geosynthetic clay liner (GCL); solution characteristics; swelling features; hydraulic properties