Effect of cation exchange capacity of soil on stabilized soil strength

While a certain correlation between the cation exchange capacity (CEC) of the soil and the strength of the cement stabilized soil has been reported, the mechanism remains unclear. In this research, a set of soil samples with different CECs were stabilized with different proportions of cement and calcium hydroxide (Ca(OH)2, CH). The influence of soil CEC on the strength of the stabilized soil was investigated by analyzing the CH saturation in the pore solution and measuring the strength of the stabilized soil specimens. It is revealed that cation exchange in the soil can reduce the CH saturation of the stabilized soil. If the CEC of the soil is too high, the CH in the pore solution of the stabilized soil cannot reach the saturation level, and further cation exchange would then consume the Ca2+ ions which should be originally used to generate calcium silicate hydrate, thus result in the poor strength of the stabilized soil.