Corrosion evaluation of prestressed high-strength steel wires with impressed current cathodic protection based on acoustic emission technique

The acoustic emission (AE) technique is a non-destructive testing method widely used in various structural health monitoring fields, and it is highly sensitive to the emergence and development of material corrosion. This study developed a method of employing the AE technique to evaluate the corrosion degree of stay cable high-strength steel wires under pre-stress and impressed current cathodic protection (ICCP) in a simulated marine atmospheric rainwater environment. The variation characteristics of AE parameters under various pre-stress levels and protection current densities were investigated. Results showed that the more negative the open circuit potentials (OCPs) and the greater the average corrosion rates, the higher the cumulative AE parameters. In the AE intensity analysis of corrosion damage for stay cable high-strength steel wires, the constants J and the K were taken as 40 and 25 hits, respectively. The corrosion of steel wires was divided into no corrosion, slight corrosion, medium corrosion, and severe corrosion. The corrosion degree of specimens with ICCP was classified as no corrosion and slight corrosion, whereas that of unprotected specimens was classified as medium corrosion and severe corrosion.