This working group, which was newly established in April 2021 focuses on the relationship between the microstructure (phase assemblage and pore network) and the macroscopic properties of cement paste. In particular, the durability of blended cement system, or innovative cementitious binders are analyzed, with a particular attention to chloride ingress and carbonation.

Our approach is to develop a systematic and fundamental approach to understand these processes for a wide range of binders by combining experiments and models.

The experiments focus on the quantitative analysis of phase assemblage (XRD-Rietveld, TGA, SEM-EDX, pore solution analysis, 1H NMR, …), the pore network (porosity, MIP, 1H NMR, N2 adsorption, …) and the macroscopic transport properties (penetration depths, diffusion coefficients, compressive strength…). These experiments are often complex to analyze in cementitious materials, and an objective of this group is to develop reliable methods to interpret the experiments.

The models aims to analyze and correlates these results to obtain a fundamental understanding of the processes involved in the clinker formation, and the hydration, and the long-term lifespan of a cementitious sample. Thermodynamic models are used to understand the formation and reactivity of the anhydrous phases, as well as the formation, and stability of the hydrates, or carbonated phases. Kinetic models are used to understand the limiting step leading to the stable phase assemblage. Finally reactive transport model are used to combine these effects to the transport of species in and out of the cementitious material. Both custom codes (SpecMICP, ReactMICP), and codes from the community (GEMs, PhreeqC, …) are used to run the simulations.