Water and salt migration model of solidified sulfate-contaminated soil by full solid waste cementitious materials

The limitations of the research on the water-salt migration of sulfate-stained soil using solid waste as the sole binding material, such as the difficulty in characterizing the hydration reaction products over time, were addressed in this study. The research focused on different ratios of solid waste-based binding materials for solidifying sulfate-stained soil. Through the combination of experiments and theory, a water-salt migration model for solidified sulfate-stained soil using solid waste-based binding materials was established. Compared to traditional studies, this model can represent the time-dependent characterization of the hydration process. By introducing the grey correlation degree theory and using porosity as the evaluation index, the dynamic evolution characterization of the hydration products of solid waste-based binding materials was achieved. An innovative approach was adopted to construct the relationship between porosity and matrix suction using the Logistic curve, which served as a link to establish the water-salt migration equation. The porosity was used to control the spatial-temporal distribution of water and salt, compensating for the traditional model's neglect of the influence of changes in the cementing system on water-salt migration. The influence of the amount of binder, the proportion of slag, and the salt content on the pore structure of the solidified soil was systematically clarified, verifying that an increase in binder amount, an increase in the proportion of slag, and a decrease in salt content can significantly optimize the pore structure and inhibit water-salt migration. This provides a theoretical basis for the water-salt migration of solidified sulfate-stained soil using solid waste-based binding materials.