Stabilized/solidified chlorine saline soils with ground granulated blast furnace slag and calcium carbide residue

To optimize the use of chlorine saline soils commonly found in many coastal areas, ground granulated blast furnace slag (GGBS) and calcium carbide residue (CCR) were used in this study to stabilize/solidify these soils. This study aims at evaluating the suitability of GGBS-CCR as industrial by-products in improving the mechanical behaviors of chlorine saline soil in comparison with the use of Portland cement (PC) as a traditional binder. The optimal proportion of the binder was determined by the unconfined compressive strength, conductivity, and leaching characteristics. Moreover, the water stability coefficients, collapse coefficients and microscopic characteristics of the solidified soil were evaluated. The results reveal that when the ratio of GGBS to CCR in the binder is 4:1, the 28-day unconfined compressive strength reaches 4.53 MPa, and the leaching of chloride ions is reduced by 94.1 %. The excellent water stability and reduced collapsibility further indicate that GGBS-CCR is a preferable binder for solidifying saline soil compared to PC. Furthermore, microscopic analysis revealed that chloride ions in the saline soil were involved in the hydration reaction to form Friedel's salt. [Display omitted] •The optimum binder ratio was 80 % ground granulated blast furnace slag (GGBS) and 20 % calcium carbide residue (CCR).•GGBS-CCR binder significantly improves the mechanical properties of saline soils.•The leaching of chloride ions of the solidified saline soils significantly decreased.•Chloride ions in the soil participate in the reaction to form Friedel's salt.