Multi-phase modelling of ionic transport in concrete when subjected to an externally applied electric field

Chloride-induced reinforcing steel corrosion is a worldwide problem. In order to predict how chlorides penetrate in concrete and how other ionic species in concrete pore solution affect the penetration of chlorides, this paper presents a numerical study on the two-phase modelling of ionic transport in concrete when subjected to an externally applied electric field. In most existing work, researchers tend to use the assumption of electro-neutrality condition to determine the electrostatic potential within an electrolyte in one-dimensional problems and consider only one phase. In contrast, this study employed a two-phase numerical model of concrete and the Poisson’s equation for determining the electrostatic potential. By solving both mass conservation and Poisson’s equations, the distribution profiles of each ionic species and electrostatic potential at any required time were successfully obtained. The results obtained from the present two-phase modelling reveal some important features which cannot be found from existing one-dimensional and one-phase models.

► The paper has presented a two-phase, multi-component ionic transport model. ► The model has been used to simulate the migration test of chlorides. ► Detailed distribution profiles of ionic concentrations are provided. ► Detailed distribution profiles of electrostatic potential are provided. ► This kind of models has not existed in literature.