Self-Healing Properties of Geosynthetic Clay Liners

The sealing effect and containment of moisture in landfill covers and liners containing geosynthetic clay liners (GCLs) are largely influenced by moisture retention, swelling, and the self-healing behaviour of bentonite used in GCLs. The method of binding of GCLs also significantly affects the behaviour. To examine these aspects, percent swell and swell pressure tests under different effective pressures were conducted on two sodium-based GCLs. Permittivity tests were performed on GCL specimens with different hole diameters and also on specimens dried at 20 and 60°C. The test results are presented and discussed. The study shows that the GCLs considered have a good self-healing capacity for the case of desiccation cracks or punctures. In addition, the method of binding the GCL components, i.e., stitch-bonded or needle-punched, has a significant influence.