A Preliminary Study of the Bentonite Self-Healing of Slits in a GCL upon Full Hydration

The experiments reported herein examine the self-healing of slits in GCLs upon hydration with deionized water under a confining stress of 2 kPa. Consideration is given to self-healing of 15 mm-wide, 25 mm-wide, and 30 mm-wide × 120 mm-long single slit in the center of a GCL specimen. The single 15 mm-wide slit fully self-healed after 65 days. Neither the 25 mm-wide × 120 mm-long nor 30 mm-wide × 120 mm-long single slit fully self-healed and a fully penetrating hole remained after full hydration. The self-healing of GCL specimens with 15 mm-wide × 240 mm-long double parallel slits is also examined. Full self-healing was observed when there was a 20 mm-wide strip of undamaged GCL between the slits. However full self-healing did not occur when the widths of this strip of bentonite between slits was reduced to 10 mm and 5 mm. This study also raises a number of questions such as what is the effect of stress, hydrating conditions, and mass of bentonite in the GCL that require further investigation.