Our paper on early stage carbonation of cement is published in PNAS Nexus. Concrete contributes significantly to global CO2 emissions. I'm excited to share that our MIT team has discovered new carbonation pathways that can significantly reduce this impact. Our findings show that by incorporating soluble carbonates like baking soda into fresh cement, up to 15% of the carbon dioxide associated with cement production can be mineralized during the mixing and pouring stages. This process involves a composite phase of calcium carbonate and calcium silicon hydrate (C-S-H), resulting in cement that sets more quickly and has doubled early-stage mechanical performance compared to a traditional mix.
While the concept of early-stage concrete carbonation is not new, our findings show that the capacity of fresh cement to sequester carbon dioxide has been greatly underestimated and underutilized. This points to a bright future for the development of multifunctional carbon-neutral (or even carbon negative) building materials, transforming concrete from a problem to a part of the solution.