Chlorine fixation by aluminate minerals in coastal chloride saline soil modification as subgrade material
Chlorine fixation by aluminate minerals in coastal chloride saline soil modification as subgrade material
The expanding transportation infrastructure has increased global interest in using coastal chloride saline soil in highway engineering. The engineering properties of chloride saline soil are significantly affected by soluble chloride, which limits its application in highway projects. This study investigated modification schemes that combine lime with aluminate minerals. Laboratory tests were conducted to evaluate the road performance of the modified soils. By combining quantitative analysis of chlorine fixation with microstructural evidence, the effectiveness, construction sensitivity, and mechanisms of chlorine fixation in modified soil were elucidated. Results indicate that composite modification with lime and High-alumina cement or ordinary Portland cement can significantly enhance the road performance of chloride saline soil. Aluminate minerals effectively immobilize chloride ions. Tricalcium aluminate chemically combines with chloride ions in the soil to form Friedel's salt. The chloride ion fixation rate of the modified soil increases with a higher dosage of aluminate mineral content. Within the curing temperature range of 10-30 °C, an increase in temperature can promote the chlorine fixation efficiency of aluminates. Chlorine fixation occurs primarily within agglomerates, rendering the fixation only weakly sensitive to the degree of compaction (80-96 %) regarding construction sensitivity. Based on the concept of chlorine fixation, this study aims to provide experimental evidence and theoretical references for the engineering application of coastal chloride saline soil modified with aluminate mineral-based materials.
Tianqi Wei; Hao Dai; Zi Ying; Yongfeng Deng
International Conference on Advances and Innovations in Soft Soil Engineering (ICAISSE2026)
Ground Improvement and Low-Carbon Solutions
https://doi.org/10.53243/ICAISSE2026-92