Mechanical behaviors of hydrogel-impregnated sand

Abstract Hydrogel has been widely used in medical studies due to their unique integration of solid and liquid properties. There is limited studies of using hydrogel in construction materials. The goal of this study was to investigate the effect of hydrogel on mechanical behaviors of sandy materials. The effects of reaction time, sodium alginate content, and curing temperature on mechanical behaviors of hydrogel-impregnated sand were studied through unconfined compression tests, falling head permeability tests, consolidated and undrained triaxial tests, scanning electron microscopy, and durability tests. The unconfined compression strength (UCS) increased with sodium alginate content, but the hydraulic conductivity of hydrogel-impregnated sand decreased with sodium alginate content. The optimum reaction time and curing temperature were found to be 3 days and 50 °C, respectively, for the hydrogel-impregnated sand. The stress-strain curves of hydrogel-impregnated sand indicated that the ductility of hydrogel-impregnated sand was significantly improved compared with the traditional cementitious method. Moreover, the results of durability tests indicated that approximately 60% of the original UCS of hydrogel-impregnated sand still remained after 12 wet-dry and freeze-thaw cycles.