Numerical simulation of 3D sulfate ion diffusion and liquid push out of the material capillaries in cement composites

This study treats 3D diffusion of sulfate ions into cement composite and simultaneous effects, such as microcapillary filling and subsequent liquid push out of them. A numerical algorithm provides account for various conditions specified at the interface, as well as possibility to model separate volume sections as inert fillers. Cases discussed illustrate the capabilities of the proposed model and those of the algorithm designed to study diffusion and liquid push out for specimen complex configuration. Results found allow for the assessment of the effects of convective and diffusion ion transfer. Comparison with experimental observations of corrosion processes that have more or less one-dimensional character prove the necessity to use a 3D mathematical model for a fuller clarification of sulfate corrosion.