With 70 per cent of the global population projected to live in urban areas by 2050, resilient and sustainable construction is crucial to meeting our current and future infrastructure needs. While concrete has been proven to be one of the most resilient building materials available, its massive environmental impact must be addressed to justify its continued use.
One avenue for reducing concrete’s carbon footprint is through the integration of carbon mineralization curing into the concrete production process. CO2 injection into wet concrete mix or by the curing of products in a dedicated carbon dioxide curing chamber locks emissions away into the concrete.
When CO2 reacts with calcium oxides in concrete’s binding material, it transforms into calcium carbonate, which hardens the concrete and traps CO2 within the molecular structure. The conversion of CO2 to carbonate minerals is a safe and effectively permanent form of long-term CO2 storage.
In a recent study published by researchers at the University of California, Santa Barbara, it was determined that building materials that utilize carbon mineralization technology in their production could annually store between 13.2 and 20 Gt of CO2 by 2100.
This study also assessed carbon mineralized construction materials in comparison to their conventional counterparts. It found that “many of the carbon-storing building materials we considered have the potential to be cost competitive with the conventional materials they replace owing to the low cost of feedstocks needed.”
In a 2020 assessment of carbon mineralization and carbon capture, utilization, and storage (CCUS) technologies, researchers from the University of Greenwich in Chatham, UK found that mineralized construction products will be crucial to meeting low-carbon construction goals, and that wide product certification is a must for the rapid adoption of this technology into the construction industry.
The CarbiCrete process makes use of steel slag, a byproduct of the industrial steelmaking process, as a 100% replacement for cement, concrete’s conventional binding agent. The steel slag binder enables the permanent storage of CO2 in a variety of concrete products.
Because the CarbiCrete process entirely replaces cement, the co-benefits of CarbiCrete’s technology extend beyond carbon sequestration to waste valorization, emissions avoidance, and contribution to the circular economy. Through combining cement replacement with carbon mineralization curing, CarbiCrete is developing a revolutionary construction technology with far-reaching positive implications.
