Simulating evolution in cement microstructure during chemical degradation

Calcium leaching is one of the important degradation mechanisms causing dissolution of the crystalline phases such as, AFm, portlandite increasing capillary porosity. Further it leads to decalcification of an amorphous C-S-H phase causing increase in the gel porosity and in turn degrading the long term performance of concrete structures. In this paper a lattice Boltzmann based pore-scale reactive transport approach in the context of simulating the evolution of microstructure of a hardened cement paste during calcium leaching is presented. This approach is based on fundamental principles of chemical thermodynamics and mass transport. The example presented illustrates influence of location of mineral grains and surface area on overall dissolution rate and pore structure evolution.