A comprehensive review of mechanical and durability properties of magnesium slag as a building material

Magnesium slag (MS) is a significant waste product of magnesium production. The sustainable reuse of MS presents a highly promising approach to the development of eco-friendly construction materials. The use of supplementary materials to reduce cement consumption significantly decreases the amount of CO 2 produced by ordinary Portland cement concrete (OPCC). The present study systematically analyzes and summarizes the current state of research on the mechanical, durability and micro-structural properties of MS as a building material based on the available literature. The effects of the utilization method, dosage, and curing conditions of MS on the mechanical and durability properties were discussed. Research findings on the strength and durability properties of MS as a building material remain relatively limited, and the conclusions reported in the literature show a lack of full consistency. Overall, MS can effectively serve as a supplementary binder, where an optimum substitution level of approximately 30% is frequently reported for balancing fresh-state workability and compressive strength through the refinement of the hydration product matrix. However, this value is derived from studies employing different MS sources, mix designs, activation routes, and curing conditions, and should therefore be regarded as an indicative, condition-dependent range—varying systematically with the binder type, the pre-treatment applied to the slag, and the curing regime—rather than a universally transferable design value. Accordingly, further investigation is warranted.