Effect of bentonite mass per unit area on the desiccation of geosynthetic clay liners under high temperature and low overburden pressure

In some applications where geosynthetic clay liners (GCLs) are used in barrier systems, high temperature may build up on the surface of the GCL. This may lead to dehydration and loss of performance which will, in part, depend on the desiccation and water retention properties of the GCL. This paper presents a series of experimental investigations of GCLs performance under high temperature. The behaviour of two Na-bentonite GCLs, with different mass of bentonite per unit area, is investigated. 1-D column desiccation tests, followed by X-Ray imaging, show that under high temperature (78±1oC), both GCLs experienced high levels of water loss and desiccation. However, the GCL with the larger mass per unit area had a smaller total cracks area. The drying path of the soil water characteristic curve (SWCC) also shows that the GCL with a greater mass per unit area maintained a higher degree of saturation and lower bulk void ratio at higher suctions.