The global cement industry contributes approximately 8% of carbon dioxide emissions. Utilizing low-carbon wastes such as red mud

steel slag

and fly ash to replace cement is of great significance for carbon neutrality. To address the issue of their low reactivity in geotechnical engineering applications

this study proposes an alkaline-sulfate synergistic activation method. Techniques such as backscattered electron spectroscopy and X-ray diffraction were employed to reveal the microstructural characteristics and reaction kinetics. Experimental results indicate that the concentration of alkaline solution

temperature

dissolution time

solid-to-liquid ratio

and sulfate concentration significantly affect the dissolution of Si

Al

and Ca from the waste materials. Kinetic analysis confirms that the dissolution process follows the internal diffusion mechanism of the shrinking-core model. Among the elements

Si has a lower activation energy under alkaline conditions

resulting in higher dissolution reactivity

while Ca has a higher activation energy

making its dissolution rate more temperature-sensitive. Molecular dynamics simulations show that in the NaOH-NaSO system

Si and Al exist in the form of and Al(OH)⁻

respectively. This study provides a theoretical foundation for the development of low-carbon geotechnical materials and supports the low-carbon transformation of the construction industry.