A review on carbonation of magnesia for soil stabilization sustainability: factors, mechanisms and environmental implications

Purpose Magnesia (MgO) carbonation has emerged as an innovative approach to soil stabilization sustainability, offering dual benefits in geotechnical engineering applications and environmental protection. This review aims to promote the advancement and broader application of magnesia-based soil stabilization techniques in various geotechnical contexts by identifying knowledge gaps and outlining essential research directions. Design/methodology/approach Based on a synthesis of recent research, this paper provides a comprehensive review of magnesia carbonation for soil improvement. It examines the influence of key factors, such as soil characteristics, moisture levels, CO2 concentration, ambient temperature and magnesia’s physical properties on the carbonation process. The review also focuses on microstructural changes and scaling effects observed in bio-carbonated soils, while evaluating current technical limitations and emerging opportunities. Findings The effectiveness of MgO carbonation in soil stabilization is significantly governed by multiple interrelated variables, which directly influence fundamental soil properties, particularly strength development and permeability. The review highlights how these factors control the carbonation reaction and its geotechnical outcomes, while also revealing critical gaps in current understanding and implementation. Originality/value This paper offers a timely and integrated assessment of magnesia-based carbonation for sustainable soil stabilization, linking geotechnical performance with environmental implications. By synthesizing current knowledge, identifying unresolved challenges and proposing focused research directions, the review contributes original insights that can guide future innovation and practical deployment of this eco-friendly stabilization technique.