Advanced soil carbonation strategies: insights into quantification, performance, and scalable carbon capture

Accelerated soil carbonation (ASC) is a rapidly advancing carbon capture and storage technique which provides a dual benefit of permanent CO₂ sequestration and geotechnical soil stabilization. This paper presents a comprehensive review of soil carbonation processes, emphasizing the mechanisms, quantification methods, and engineering performance improvements achieved through MgO and CaO-based binders and industrial by-products. The carbonation process transforms reactive oxides into stable carbonate minerals, enhancing soil strength, stiffness, and durability while reducing moisture content and porosity. A systematic analysis of the impact of carbonation on physical, chemical, mechanical, and microstructural behavior is presented, together with quantification approaches such as thermogravimetric analysis, calcimetry, and gas-balance techniques. The techno-economic evaluation highlights that optimized magnesia-lime-slag systems can offset up to 70 % of embodied emissions, offering a cost-effective and scalable pathway for carbon-negative ground improvement. Despite these advances, the field faces challenges related to reaction uniformity, long-term durability, and standardization of quantification and field protocols. The study identifies key research directions to establish ASC as a reliable, sustainable, and verifiable carbon sequestration strategy in geotechnical engineering.