ABSTRACT
Geosynthetic clay liners (GCLs) are widely used as a hydraulic barrier due to their low hydraulic conductivity. However, wet and dry cycles by diurnal and seasonal temperature changes and contact with electrolytes induce cracks and compression of the diffuse double layer. This hampers the efficiency of bentonite contained in the GCL. Under this situation, the polymerized bentonite (HYPER clay) has demonstrated better performance against cracking compared to untreated clay. One of the possible reasons for the enhanced efficiency might be the improvement in suction/water retention capacity. Thus, the suction characteristics of the HYPER and untreated clay GCLs were investigated. The paper presents the filter paper total suction test's results of GCLs, along drying and wetting paths, in the form of soil water retention curves and its comparison with the results of the water activity method. Distilled water and seawater were used as wetting solutions. The results showed a higher water retention capacity of HYPER clay GCLs compared to untreated clay. In short, the improved performance of HYPER clay GCLs under wet and dry cycles is partly due to enhanced suction characteristics.
