Electrochemical feature for chloride ion transportation in fly ash blended cementitious materials

The chloride transport behavior of fly ash blended cement material was investigated in this study by using electrochemical impedance spectroscopy (EIS). The chloride penetration was studied by means of EIS. A new equivalent circuit model was applied to describe the electrochemical system of fly ash blended cementitious materials. Experimental results demonstrate that the increase in the fly ash replacement ratio of sample can increase the penetration depth of chloride ion. In addition, the increase in the fly ash replacement ratio of sample can enlarge the Nyquist curve semi-circle, and improve ion transfer resistance at the solid-liquid phase interface. We determined the quantitative relationship between electrochemical properties and chloride penetration depth in order to successfully predict the chloride ion penetration depth of blended cements with varying fly ash content. It is expected to complement the existing test standards regarding the durability evaluation of construction materials.