Influence of ground granulated blast furnace slag on the dispersivity and mechanical property of dispersive soil

This paper focused on the influence of ground granulated blast furnace slag (GGBFS) on the dispersivity and mechanical properties of dispersive soil. Different contents of GGBFS, varying from 1% to 10%, were mixed in dispersive soil and curried for 28 days. Eroded soil weight and flow speed during pinhole test under different water heads were recorded. Dispersivity of soil samples was determined by pinhole test and two kinds of crumb test. Unconfined compression test and splitting test were conducted to determine the compressive and tensile strength of soil samples. Electronic conductivity and pH were also measured during curing time for all soil samples. Microstructural and mineral analyses of soil samples were performed by SEM (with EDS), XRD, and TG/DTG tests. A natural dispersive soil sample was selected to validate the improving effectiveness of GGBFS on the dispersivity and mechanical property of dispersive soil. Experiments show that water stability, compressive strength and tensile strength of dispersive soil are significantly improved with the increase in the mixed content of GGBFS in soil. Results indicate that GGBFS is capable of improving both the dispersivity and mechanical properties of dispersive soil, and this effect is more obvious with the increase in curing time. Appropriate curing time is encouraged during the construction process to intensify the improving effect of GGBFS. Enhancing of water stability of dispersivity soil by GGBFS would ensure the safety and normal operation of soil constructions in geotechnical, agricultural, and hydraulic engineering, which could be a win-win application in the future. The use of GGBFS can effectively reduce the environmental problems caused by the use of traditional high carbon emission materials such as cement and lime.