Hydration/dehydration behavior of GCLs under extreme cold environments

Geosynthetic clay liners (GCL) have been used as hydraulic barriers in cold climates where there is a relatively short period of above zero temperature when hydration can occur and a relatively long period of sub-zero frozen conditions when the hydration process stops. Although the GCL hydration process in cold regions has been addressed experimentally using soil column tests, the influence of low temperature (close to 0°C) and low relative humidity (< 10%) has not been considered for the experiments, which might reduce the final saturation of the GCL. The GCL hydration/dehydration phenomena under the above conditions is examined in this paper. Results from the experiment run at +1.5°C show that the final gravimetric water content (GWC) achieved is not influenced by the low temperature compared to room temperature. Results from the experiments at -2°C show that the GCL may absorb ~+12% (GWC) of water before the system becomes fully frozen.