ABSTRACT
Geosynthetic clay liners (GCLs) are new construction materials which make it possible to use very thin bentonite layers for sealing purposes in construction practice. Only with the development of GCLs has it become possible to exploit pure bentonite's sealing qualities over large surfaces, using a very fine layer to save space. It is also known that highly plastic clays have little shear strength. It would be highly desirable for all committees involved to cooperate constructively, so that standardized guidelines for the testing and use of GCLs in Germany become available in future. In the USA, GCLs are evidently often used instead of mineral sealing layers in combination seals for landfill construction, as landfill liners and covers. There, the sealing systems are so planned that by systematically comparing individual features, e.g., water permeability, adsorption capacity and the diffusion coefficients, the equivalency of GCL with mineral sealing layers may be assessed.
