It is essential to develop an inspection method capable of diagnosis for corrosion of reinforcing steel inside the concrete structure since the aging of reinforced concrete (RC) structures is in progress. However, in the conventional methods, it is necessary to partially destroy the existing structure to measure the corrosion rate of the reinforcing steel. In this work, to develop a non-destructive method to measure the corrosion rate of the steel inside the existing structure using a four-probe AC impedance method, the impedance is measured for mortar and concrete specimens. Also, current dispersion analysis clears the change of the measurement value depending on the probe distance and the rebar depth.
As a result, we succeeded in proposing a condition capable of applying the method and an index capable of converting into a corrosion rate under the condition. It is shown that we can set a measurement condition according to a targeted concrete structure and evaluate the corrosion rate of the reinforcing steel using the non-destructive method.
