Modelling of EDL effect on chloride migration in cement-based materials

The shortcomings of the geometrical approach for studying the chloride ingress through cement-based material have been highlighted previously. Improving this approach requires taking into account the electrical double layer (EDL) occurring at the interface between the pore walls and the pore solution. This is the aim of the present work. First, it is shown that the viscoelectric effect of EDL depends on pore diameter and zeta potential. Second, the decelerating effect of EDL is seen to induce a decrease in co-ions flux and an increase in counter-ions flux. Finally, the proposed macroscopic model is validated through monitoring of current densities during chloride migration tests carried out on cement mortars. Simulated current densities are found to be in good agreement with measured values.