Compression Behavior of Rubber–Bentonite Mixture under Different Salinities

Abstract

This study investigated the engineering properties of a rubber–bentonite mixture under different salt solution concentrations, mass ratios, and consolidation pressures. In addition, the effects of different solute ion concentrations on the compression index of the samples were compared. The results showed that the compression coefficient could be reduced effectively by increasing the weight percentage of rubber without being affected by the salt solution. However, with the increase in the salt solution concentration, the compression coefficient of mixed materials with different mass ratios increased, and when the salt solution concentration exceeded 0.5 mol/L, the compression coefficient increased more obviously. In a 0.1 mol/L NaCl solution, the addition of different levels of rubber could increase the compression modulus of the mixed material and reduce the compression ratio of the mixed material. This showed that in an environment with a low salt solution concentration, adding rubber into the mixed material could enhance its compressive deformation resistance. However, when the rubber content exceeded 50%, significant pores appeared in the sample, and the effect of high salt solution concentration intensified. The rubber content also had an effect on the swelling properties of soil, and the degradation of rubber in the salt solution showed reduced mechanical properties. This emphasizes the need to consider the stability and resistance of saline–alkali areas to salt erosion.