Effect of 95 °C temperature on the chloride-migration of concrete using electrical field

The effects of 95 °C temperature on the chloride migration (the non-steady-state migration coefficient and the steady-state migration coefficient) of concrete are investigated. The transport properties of control specimens (at room temperature) and heated specimens (at 95 °C temperature) are prepared and studied. In this study the electrochemical technique is applied to accelerate chloride ion migration in concrete to estimate the breakthrough time and the chloride flux. The non-steady-state chloride migration coefficient and the steady-state chloride migration coefficient of concrete are calculated from the modified Fick's second law based on measurements of the breakthrough time and the chloride flux. Sixteen mixes of concrete are tested in this study. The results show that the non-steady-state migration coefficient and the steady-state migration coefficient increase by about 3-11 times and by 3-7 times, respectively, when the temperature is raised from room temperature to 95 °C. It could be assumed that these results are due to the increased connectivity of pores resulting from the increased pores around the interface between aggregate and matrix. The probable increased connectivity of pores at the interfacial transition zone (ITZ) of the specimens could have a major influence on the chloride migration coefficients of concrete.