The chloride ponding test and its correlation to the accelerated chloride migration test for concrete

In this study, the total chloride content and penetration depth of concretes were measured by the 90-day salt ponding test, and the flux of chloride ions passing through the concrete was measured by the accelerated chloride migration test (ACMT; the electrochemical technique is applied to accelerate chloride ion migration). Fick's second law was fitted to the data from the ponding test to determine the diffusion coefficient. The steady-state and the non-steady-state migration coefficients were determined from the modified Fick's first and second laws, respectively. The steady-state migration coefficient, the non-steady-state migration coefficient, and the diffusion coefficient were compared. The non-steady-state migration coefficient, steady-state migration coefficient, and diffusion coefficient were linearly correlated. The non-steady-state migration coefficient gave the highest value, being about 1.5 times higher than the steady-state migration coefficient, and up to about 4 times higher than the diffusion coefficient. Since the 90-day ponding test is time-consuming, the ACMT provides a time saving method to obtain the transport property of concrete.