Abstract
In this study, the influences of cover concrete properties (depth, degree of saturation, chloride ion concentrations, cement type, W/B, liquid phase on steel bar) were quantitatively examined by using electrochemical measurements. The difference due to the membrane potential (MP) between the half-cell potential measured on the cover concrete and the half-cell potential measured at the surface of steel bar could be observed. And the difference became larger as the degree of saturation of cover concrete became lower or the microstructure of cover concrete became denser. And, it was found that the impedance spectroscopy was affected by cover concrete properties. The impedance spectroscopy at low frequency response was related to the steel corrosion process, considering that the response at high frequencies was attributed to the cover concrete properties. Based on these results, the equivalent electrical circuit for reinforced concrete was proposed. And the differences between the proposed equivalent electrical circuit and Randles equivalent electrical circuit were discussed.
