Indirect evaluation of the swelling-shrinkage potential of Bentonite soil through analysis of the stress-strain behavior of its stabilized sample with cement and epoxy resin in the durability process

Abstract

Abstract Bentonite soil containing predominantly Montmorillonite minerals has the highest tendency to absorb water and swell. No study has been done yet to stabilize Bentonite soil to last against successive wetting and drying cycles. In this research, Bentonite soil with approximately 45 wt% Montmorillonite mineral of the total amount was stabilized with cement and epoxy resin additives by gradually increasing the ratio of epoxy resin to water to withstand six successive W/D cycles. The uniaxial tests were performed on the stabilized samples after curing and 24 h of soaking in the third and sixth cycles. The swelling-shrinkage potential of Bentonite soil was evaluated by analyzing their stress-strain behavior, and it was predicted indirectly by determining the strength parameters. The results showed that for different amounts of cement, the minimum ratio of epoxy resin to water added to Bentonite soil to last up to six cycles was equal to 1. Also, by stabilizing the Bentonite soil so that the total weight of the optimum moisture content was replaced with epoxy resin, the strength and rigidity attained the level of normal concrete, with the difference that the ductility was much more significant. The failure strain value increased by 32 times, and the plastic region of the stress-strain curve expanded over the wide strain interval with a length of about 5%. In order to overcome the swelling-shrinkage potential of Bentonite soil at the level on which no cracks developed during W/D cycles, the strength and ductility properties got to at least the mentioned level of stabilization.