Effect of Cationic Exchange Capacity of Soil on Strength of Stabilized Soil

Consumption of Ca and OH in soil may cause the pore solution in the stabilized soil Ca(OH)2 unsaturated, and thus reduces the amount of cementious hydrates generated by the cement hydration, which impedes strength growth of the stabilized soil. It is not clear that what kinds of factors have influence on Ca(OH)2 saturation in the stabilized soil. In this research, a set of soil samples with different cationic exchange capacity were selected, stabilized soil specimens are prepared by mixing the soil samples with different proportions of cement and Ca(OH)2. The influence of soil cationic exchange capacity on the strength of the stabilized soil are investigated by means of measuring the concentrations of main ions in the pore solutions squeezed from the stabilized soil specimens and the strength of the stabilized soil. It is revealed that: cationic exchange of the soil samples depresses the Ca(OH)2 saturation of the stabilized soil. When the cationic exchange capacity of the soil samples is high enough, the Ca(OH)2 concentration of the pore solution in the stabilized soil cannot get saturated, under these conditions, further cationic exchange depletes Ca 2+, OH- which shall be used to generate calcium silicate hydrate, so the amount of calcium silicate hydrate decreases, which results in the poor strength of the stabilized soil.