Multiscale Analysis of Carbonation-Induced Microstructural Changes in Cements

Carbonation of concrete, besides chloride ingress, is often at the origin of the corrosion of steel reinforcement which is one of the main causes of damage to concrete structures. Concrete with blended cement is even more vulnerable to carbonation due to intrinsic features of hydrate phase assemblage, pore structure and transport properties. Little is still known about the microstructural changes and water release due to the polymerization of hydrates upon carbonation, and its impact on the transport of CO2m thereby the carbonation rate and process in the long term. This project adopts a multiscale approach in which carbonation kinetics and microstructural alterations of single (e.g. CH, C(-A)-S-H, Afm, Aft) and multiple hydrates are experimentally investigated to elucidate the origin of carbonation-induced alterations in the microstructure of SCM-containing cement. Research findings will allow us to resolve the vulnerability of these cement to carbonation, to accurately predict long-term carbonation ingress in concrete and to determine the best strategies to increase the durability of concrete structures against carbonation-induced reinforcement corrosion.