Effect of salt concentrations on the hydraulic conductivity of the mixtures of basalt soil and various bentonites

The present paper describes the influence of the various concentrations of NaCl and CaCl₂ on hydraulic conductivity of the mixture of basalt soil and four different bentonites in the proportion of 100:20 by dry weight. The comparison of hydraulic conductivity (k) for a given salt solution on a particular soil mixture shows that the k decreased with decreasing the salt concentration. The decrease in k with a decrease in salt concentration can be attributed to increase in diffuse double thickness. The comparison of k for different salt solution shows that the divalent cation had more effect compared to the monovalent cation. However at 1 mol_c/L concentration almost an equal value of k was observed. With increasing the salt concentration from 0 to 0.1 mol/L, the k changed significantly which was more prominent for the sample with CaCl₂ solution. The results show that for a particular salt concentration mixture with higher liquid limit exhibited a lower k. However with increasing the salt concentration, the liquid limit converged and also the k.