Wangcheng Yu

The high carbon emissions associated with cement-based materials in lightweight foamed soils have become a significant environmental concern. In addition to this applied problem, there is also a scientific challenge: current studies of carbon–magnesium reactions in lightweight carbonated soils (LCSS) lack multiparameter predictive models, which are essential for understanding the coupled effects of MgO dosage and CO₂ foam content on material performance. This study addresses this gap by systematically investigating the influence of MgO and CO₂ foam on the strength, resistivity, and carbonation behavior of LCSS. A multiparameter regression model was developed to predict these properties, and its statistical significance and predictive accuracy were verified. The results show that MgO dosage strongly promotes carbonation and strength development, while CO₂ foam content primarily regulates porosity and carbonation degree. The established model provides reliable predictions of LCSS performance and offers a scientific basis for optimizing carbon–magnesium reactions in sustainable soil stabilization.

This study, from the perspective of resource utilization and carbon sequestration, developed a novel lightweight carbonated solidified slurry material using reactive magnesium oxide (MgO), ground granulated blast furnace slag (GGBS), and carbide slag as stabilizers, with carbonation induced by a CO₂ foaming method. The physical and mechanical properties of the material were investigated. Based on the optimal mix proportion, the effects of MgO content, CO₂ foam dosage, and stabilizer dosage on wet density, flowability, moisture content, and unconfined compressive strength were analyzed. The results indicate that wet density increases with increasing MgO and stabilizer content but decreases with increasing CO₂ foam dosage. Flowability decreases with increasing MgO and stabilizer content but improves with a higher CO₂ foam dosage. Unconfined compressive strength increases with curing age and stabilizer content but decreases with increasing CO₂ foam dosage. Additionally, prolonged curing enhances both moisture content and unconfined compressive strength. These findings provide a theoretical basis for engineering applications.