A Study on Galvanic Sensors for Monitoring the Corrosion Damage of the Steel Embedded in Concrete Structures Part 2: Laboratory Electrochemical Testing of Sensors in Concrete

摘要

The correlation between, sensor output and the corrosion rate of steel bar was confirmed in concrete environment. Monitoring of open-circuit potential, linear polarization resistance (LPR) measurement and electrochemical impedance spectroscopy (EIS) were used to evaluate the corrosion behavior of steel bar embedded in concrete. Also, galvanic current measurements of designed sensors were conducted to obtain the charge of sensor embedded in concrete. In this study, the results of corrosion behavior of reinforcing steel showed a consistence among the data obtained by open-circuit potential monitoring, LPR and EIS measurements. Steel/copper sensor showed a good correlation in concrete environment between sensor output and corrosion rate of steel bar. However, there was no relationship between steel/stainless steel sensor output and corrosion rate of steel bar due to the low galvanic current output. Through the relationship between the steel/copper sensor output and the corrosion rate of reinforcing steel, real corrosion damage of the reinforcing steel can reliably be detected.