Durable Mg-based cement: Toward carbon-negative concrete (DCM)

Cement is an essential material used to build homes and infrastructure. Its demand will reach ca. 6 billion tons per annum in 2050 proportionally with the rise of human population. The industry is, therefore, responsible for 5–8% of total anthropogenic carbon emissions. A potential alternative cement based on hydrated magnesium carbonates (HMCs), which could bind CO2 during manufacturing, has attracted immediate interests in the construction industry. However, the current limits of HMC-based cements lie in 1) low carbonation efficacy and 2) unstable phase assemblage, leading to risks in long-term durability. Here, the project directly tackles the two bottlenecks. Inspired by the nature, we will uncover the principal mechanisms of HMC precipitation with the presence of organics (e.g., chitosan) and dopants utilizing the lens of non-classical crystallization. Such discoveries will advance our understanding of driving forces to stabilize HMCs and pave the way for carbon-negative concrete.