Stabilization of Expansive Clayey Soil Through Hydrogel for Mechanical Improvements

This study aimed to use hydrogel to stabilize expansive clayey soil. The effect of sodium alginate content on mechanical behaviors, swelling, and durability of hydrogel-impregnated clayey soil were investigated through unconfined compression tests, consolidated and undrained triaxial tests, free swelling tests, and durability tests. The tests results indicated that the sodium alginate added in the clay soil had a positive effect on the residual strength of the soil samples. The Ca-alginate hydrogel produced in the soil samples improved their ductility significantly. The swelling deformation of clay soil decreased along with higher sodium alginate content. The results showed that the swelling deformation decreased from 0.8 mm to 0.5 mm when 0.4% sodium alginate was added in the clay soil which was nearly 37.5% reduction. The connection between clay soil particles was improved by the gelation connection provided by hydrogel the friction of soil was also enhanced a lot. For wet–dry and freeze–thaw cycles, 60% and 80% of the original unconfined compression strength of hydrogel-impregnated clay remained after 12 cycles. It can be concluded that the Ca-alginate hydrogel has a good durability performance against wet–dry and freeze–thaw cycles.