A chemo-damage-transport model for chloride ions diffusion n cement-based materials: Combined effects of sulfate attack and temperature

Corrosion of reinforcement caused by chloride penetration has become the primary factor of concrete durability in the saline soil environment. A chemo-damage-transport model for chloride diffusion is studied, in which the effects of sulfate attack and temperature on chloride diffusivity in concrete are taken into consideration. Specifically, the volume changes of Friedel's salt and ettringite can cause the expansion and cracking of cement-based materials. Meanwhile, temperature has a significant influence on the reactions rates, mass transfer and ions diffusivity. The model is validated by published experimental results. The main conclusion is that there exists a peak value of the bound chloride ions. Near the exposed surface of the samples, the bound chloride content decreases with the increase of temperature. For the peak corresponding position and inward part, with the temperature rises, the bound chloride content in cement-based materials increases obviously. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

In this study, a chemo-damage-transport model for chloride diffusion was established to consider the effects of sulfate attack and temperature on chloride diffusivity in concrete, and validated by experimental results. The main conclusion drawn is the existence of a peak value of bound chloride ions.