Influence of ambient pressure on carbon sequestration of steel slag-based materials

Steel slag is a by-product generated during steelmaking processes. However, it can be reused and converted into a valuable building material by early-age ambient pressure carbonation which is different from mineral carbonation. Different types of steel slag may have different carbon sequestration behavior. The main reactive materials with CO₂ are dicalcium silicate and tricalcium silicate while the carbon sequestration of already-formed steel slag-based concrete products will be primarily affected by the material composition, carbonation time, pressure, temperature, and CO₂ concentration. It is found that ambient pressure still can promote CO₂ diffusion inside steel slag-based products. Comparable CO₂ uptake, compressive strength, microstructural development, and improved environmental benefits as high pressure are presented in ambient pressure regarding the carbon sequestration of steel slag-based concrete products. The application of ambient pressure carbonation can not only create a closed-loop system connecting CO₂ resources and concrete plants but also make contributions to emissions reduction. © 2024 Elsevier Ltd. All rights are reserved including those for text and data mining AI training and similar technologies.