Combined effect of carbonation and chloride ingress in concrete

• A comprehensive model for the combined carbonation and chloride ingress in concrete is developed.
• The effect of CSH is directly considered for the estimation of the degree of carbonation.
• The changes of the pore structure and the binding capacity are considered for the combined action.
• The corrosion initiation can be accelerated significantly by the combined mechanism.

The combined effect of carbonation and chloride ingress in concrete is studied in this paper. Based on the change of the pore structure and the chemical equilibrium, a comprehensive model is proposed for this problem. A coupled simulation of the transports of carbon dioxide, chloride ions, heat and moisture is carried out. Several sets of experimental data were compared with the prediction by the numerical model developed in this paper, for its verification. Parametric study shows that the differences between the combined mechanism and the independent mechanisms are significant in many aspects.