A direct method for determining chloride diffusion coefficient by using migration test

Calculation of the effective diffusion coefficient is proposed using an analytical model based on Nernst-Planck equation, on electroneutrality and on measurements of current intensity. To validate this approach, migration tests were carried out on different w/c mortar samples. In steady state, the resulting effective diffusion coefficients are larger than those usually obtained with models based on Nernst-Planck equation without electroneutrality. An explanation of these differences and the importance of electroneutrality are discussed in the present work.