Influence of normal stress on hydration of gcls from subsoil
Geosynthetic Clay Liners (GCLs) are often used as part of a barrier system in modern landfills to prevent the escape of leachate into the surrounding environment. The hydraulic performance of GCLs depends on the degree of hydration from the underlying subsoil. The hydration behav-iour of two GCL products from different underlying subsoils was examined under various nor-mal stresses (0 to 8 kPa). The rate of hydration of GCLs significantly increased as the normal stress, provided by the waste or leachate collection system, increased from 0 to 8 kPa. For in-stance, the final equilibrium moisture content of the GCL was achieved in approximately 8 weeks when placed on sand subsoil under 8 kPa normal stress, while it took about 24 weeks for the same GCL under no normal stress. However, the effect of the normal stress on the final equilibrium moisture content of GCLs was not so significant. A normal stress of 2 kPa was shown to induce slightly higher equilibrium moisture uptake for most GCLs. Nevertheless, re-sults indicated a meagre variation of the equilibrium moisture content as the normal stress in-creased from 2 to 8 kPa. The GCL manufacturing processes and the grain size distribution of the subsoil were shown to affect both the rate of hydration and the final equilibrium moisture content attained.
|Keywords||Geosynthetic Clay Liners (GCL), Hydration, Landfill barrier system, Normal stress|
|Journal||Journal of Solid Waste Technology and Management|
Sarabadani, H., & Rayhani, M.T. (2014). Influence of normal stress on hydration of gcls from subsoil. Journal of Solid Waste Technology and Management, 39(4), 292–303. doi:10.5276/JSWTM.2013.292