A comprehensive review of mechanisms, techniques, and precursors in enforced carbonation for low-carbon concrete

Enforced carbonation (EC), a promising mineral carbonation technique, offers the dual benefits of carbon sequestration and the production of value-added, low-carbon construction materials. The emergence of new EC techniques now spans almost all stages of concrete production—from raw material preparation to batching and mixing, through to final hardening and curing, and even into the material's service life. While these advancements have broadened the range of available EC approaches, they have also introduced increased complexity and reduced overall adoptability and compatibility due to the distinct mechanisms, reactants, and reaction environments, which are governed by the type of precursor, the target product, and the interplay with hydration. Furthermore, even within a single precursor type, particularly for waste-derived materials, substantial variability in inherent properties can profoundly influence the performance of carbonated value-added products. As a result, careful consideration is essential when transferring parameters and setups between stages to optimize the benefits of carbonation while mitigating adverse effects, such as over-carbonation. To address this issue, this review critically examines EC applications at various stages of the concrete lifecycle, including the raw material state, fresh state, and hardened state, with the aim of providing guidance for optimizing EC parameters, tailoring techniques to specific precursors, and advancing its integration into sustainable construction practices. • Reviews enforced carbonation techniques across raw, fresh, and hardened stages. • Highlights precursor variability and enforced carbonation -hydration interaction risks. • Recommends tailored enforced carbonation settings for durability and scalability.