Coupled multi-physics simulation of chloride diffusion in saturated and unsaturated concrete

Chloride-induced corrosion of steel reinforcement is one the major long-term deterioration mechanisms for reinforced concrete infrastructures. Chloride transport through cement-based materials a complex chemo-physical process involving ionic diffusion in concentrated solution, pore structure, chemistry, membrane permeability matrix, cracking, and variation internal external environmental conditions. Although literature there are plenty both simplistic phenomenological models sophisticated models, this study, new model developed taking aim at capturing fundamental physics and, same time, having formulation as simple possible that it can be effectively calibrated validated using available limited experimental data. The couples with micro-structure evolution due to continued hydration accounting hygro-thermal variations their effects on processes. implemented semi-discrete conduit network mimics heterogeneity cementitious material by connecting matrix space between coarse aggregate pieces. This allows replicate naturally meso-scale tortuosity effect which an important feature towards representing realistically heterogeneity-induced chloride concentration within concrete. parameters carefully simulating multiple experiments ranging from pastes large cylinders. results numerical simulations show ability describe spatial temporal samples under varying concentrations temperature boundary conditions saturated unsaturated