Cement and concrete as carbon sinks: Transforming a climate challenge into a carbon storage opportunity

Övrig text i vetenskaplig tidskrift, 2025

Cement and concrete, while traditionally recognized as one of the main contributors to anthropogenic CO2 emissions, also have untapped capacity to serve as substantial carbon sinks. This paper provides a comprehensive perspective on how engineered mineral carbonation can transform cement-based materials into carbon storage systems. We briefly review the fundamental mechanisms of CO2 storage in cementitious systems and highlight current limitations in understanding of reaction kinetics, end-phase regulation and performance control. The effect of CO2 uptake on material performance is critically evaluated with respect to the fresh performance, mechanical properties and long-term durability. Emphasis is placed on the valorization of alkaline industrial residues and emerging carbonatable binders, which offer sequestration capacity and sustainable resource use. A strategic roadmap is proposed with integration of scientific innovation, regulatory alignment, and carbon accounting in the life cycle, to accelerate the adoption of carbon-storing concrete. This perspective provides a framework to advance cement and concrete as engineered carbon sinks and supports the transition to a climate-positive construction industry.