Investigating the Interplay Between Carbonation Kinetics and Water Dynamics in Cementitious Materials Using Inelastic Neutron Scattering

The use of concrete has been growing continuously in the 20th and 21st centuries. The manufacture of cement, the ‘glue’ in concrete, is associated with significant CO2 emissions accounting for approx. 7% of the anthropogenic CO2 emissions in the world. The current global warming crisis and the significant consumption of natural reserves have pushed the building industry to search for new and sustainable solutions. New breakthrough technologies for lowering the CO2 footprint include a circular utilization of demolished concrete. This technology, currently under development by the cement industry, consists in the reactions between the hydraulic cement components and their hydration products with carbonate ions (from the injected CO2) in a humid environment, which lead to the formation of carbonate minerals and therefore to the permanent storage of the CO2 in solid form. Here, we aim to understand the role of the water dynamics on carbonate mineral formation pathways in the complex environment of a recycled cement paste using Inelastic Neutron Scattering. This project is part of a collaborative research PhD project led by ISTerre (CNRS & Univ. Grenoble Alpes) in collaboration with Heidelberg Materials.