Nucleation-Driven Cement Dissolution Reaction Rates through Gap-bridging Multiscale Modelling (CEMBRIDGE-2)

• Applicants: Professor Dr.-Ing. Eduardus Koenders, Ph.D.; Professor Dr. Bernhard Middendorf; Dr.-Ing. Neven Ukrainczyk, Ph.D.
• Subject Area: Construction Material Sciences, Chemistry, Building Physics
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 455605608

The initial CEMBRIDGE project aimed to understand initial stages of cement dissolution in dilute concentrations using Molecular Dynamics and atomistic Kinetic Monte Carlo simulations. The follow-up CEMBRIDGE-2 project seeks to develop an upscaled atomistic model to investigate the concentration-dependent cement dissolution, driven by reversible chemical (pre-)nucleation mechanisms. The project will study belite initial hydration rates using numerical and experimental methods. The upscaled atomistic model will simulate the combined effects of nucleation of metastable amorphous hydrates and the pore solution chemistry, which interrupt the dissolution of clinker crystallographic surfaces. This fundamental basis will include the effect of C2S synthesis and activation of the nucleation-driven dissolution of cement during hydration, allowing for improved performance and optimization of cement-based materials. CEMBRIDGE-2 comprises four work packages to investigate i) metastable CSH homo- and hetero-nucleation through MD simulations, ii) Coarse Grained Monte Carlo upscaling simulations, iii) upscaling C2S dissolution rates affected by the hetero-nucleation through atomistic Kinetic Monte Carlo simulations, and iv) model validation through experimental measurements which include C2S synthesis parameters, Hydration-Reaction Calorimetry, pore solution analysis, and characterization of the hydrating C2S surface nano-topology. The collaboration between the applicants continues in CEMBRIDGE-2, with each leading different atomistic MD and upscaling CGMC and KMC simulation tasks at various scale levels. A complementary laboratory experimental program will also be conducted to validate the numerical models.

• DFG Programme: Research Grants