The chemical compatibility study between salt solution and sodium bentonite plays an important role in evaluating the service performance of the antifouling barrier. Effects of different concentrations of NaCl solution and CaCl2 solution on the permeability

swelling characteristics

and plasticity of sodium bentonite were studied by hydraulic conductivity test

free swell test

and water ratio limit test. Experimental results show that as the concentration of the cations in the solution increased

the hydraulic conductivity of the sodium bentonite increased

the swell index first increased and then decreased

and the plasticity index decreased. At the same concentration

the hydraulic conductivity of the sodium bentonite in NaCl solution was lower than that in CaCl2 solution

and the swell index and plasticity index were both higher than those in CaCl2 solution. Within the consolidation pressure range of 12－800 kPa

the hydraulic conductivity had a strong correlation with the swell index and plasticity index in CaCl2 solution; in NaCl solution

when the solution concentration exceeded the critical concentration (200 mmol/L)

the hydraulic conductivity also had a strong correlation with the swell index and plasticity index. Therefore

it is feasible to replace the hydraulic conductivity test with water ratio limit test and free swell test.