CO 2 sequestration through alkali-activated steel slag: a review

Alkali-activated materials have been intensively researched using industrial by-products such as slag and fly ash to minimize the construction industry's carbon footprint. In the carbon dioxide (CO2) sequestration strategy, accelerated mineral carbonation is a specific method in which CO2 reacts with mineral oxides to form stable carbonates. Accelerated carbonation using alkali-activated slag (AAS) can completely replace cement for the construction material with sufficient strength. This method can permanently store CO2 in construction products. In this review, the various parameters, such as curing temperature, relative humidity, CO2 concentration, curing period, type of activator used, and alkali concentration, affect the accelerated carbonation of AAS and CO2 uptake of AAS is discussed. Increasing the parameters beyond a specific limit can be detrimental to the specimen. The findings suggest that the accelerated carbonation curing of AAS demonstrates the technology's novelty as a green cement-free technology that can reduce the adverse effects of global warming.