Experimental study of the effect on one-dimension erosion of compacted bentonite

Abstract

Bentonite swells after absorbing water and forms colloids that can release gel particles into solution causing the erosion of bentonite particle. The process of colloidal erosion can be described by the free expansion of bentonite. A new designed one-dimensional free swelling tests is performed to simulate one dimension erosion of compacted bentonite. Compacted specimens are made into two initial dry densities and water contents. De-ionized water and NaCl, Na 2 SO 4 , CaCl 2 solutions with concentrations of 0.1, 0.5, 1.0 and 2.0 mol/L were used to soak the specimens. The effects of initial dry density, initial water content and saline solution on the free swelling behavior of compacted commercial bentonite are analyzed. Results show that, the final total swelling deformation is almost independent of initial water content, but increases with the initial dry density and decreases with the increase in osmotic suction of the infiltration solution.