A chemo-transport-damage model for concrete under external sulfate attack

Sulfate-induced deterioration can reduce the service life of a concrete structure. A coupled chemo-transport-damage model for external sulfate attack is developed, which predicts the effects of calcium leaching and temperature on the deterioration processes. Specifically, calcium leaching is described using a solid-liquid equilibrium curve, and temperature effects are included in the creation of a temperature gradient and in the rates of chemical reactions, calcium leaching, and ion transport. The model is validated using published experimental results, and the effects of calcium leaching and temperature on expansion are analyzed. The results show that model predictions agree well with the available experimental data. One conclusion is that calcium leaching has a strong effect on deterioration, and therefore should be included when modeling external sulfate attack. Temperature influences sulfate attack, but a more substantial conclusion about the effect of temperature requires further experimental evidence.