Abstract
Infrastructures such as bridges, highways, pipelines and harbor piers sometimes suffer from corrosion damage during their service life. To diagnose deterioration of infrastructures and secure effective maintenance, in-situ corrosion monitoring methods based on electrochemical impedance techniques have been developed. This paper reports four examples of new corrosion monitoring sensors: 1) a sensor for measuring corrosion rate of marine steel structures in sea water, 2) a sensor for measuring corrosion rate and detecting corrosion spots of reinforcing bars in concrete, 3) a sensor for monitoring the protectivity of painted steel structures in atmosphere, and 4) a sensor for monitoring corrosion protectivity of the rust forms of weathering steel structures. The effectiveness of these sensors has been verified by experiments both in the laboratory and in the field.