Visualization of a desiccated geosynthetic clay liner due to dehumidification using micro-focused X-ray computed tomography

Abstract

The objective of this study was to evaluate the change in the barrier performance of a geosynthetic clay liner (GCL) as a result of desiccation due to dehumidification at 55°C. Specimens of GCL that were damaged by desiccation were scanned using a micro-focused X-ray computed tomography (CT) scanner, and crack generation under two different dehumidification conditions was examined using the results of image analysis. Permeability tests were performed to estimate the hydraulic conductivity of GCL damaged by desiccation with respect to a calcium chloride solution. The results obtained indicate that dehumidification and a space between a GCL and a membrane sheet are key factors in the generation of cracks in the bentonite layer of a GCL at 55°C.