The study concerning corrosion and cathodic protection monitoring has been mainly focused on qualitative methods by means of electrochemical measurements such as corrosion potential, polarization resistance, corrosion current, and AC impedance. Quantitative methods measuring the corrosion have been suggested in laboratory
experiments so far; however, it was difficult to monitor corrosion and protection states in concrete field structures. In addition, an accurate measurement and a detailed analysis are necessary to confirm the protection state and monitor the deterioration process quantitatively in inhomogeneous conditions such as reinforced concrete. In order to solve the above mentioned problems, various monitoring sensors and/or equipments for monitoring corrosion and cathodic protection have been developed. However, most of these sensors and equipments
have been dependent on import and it had many disadvantages such as high expense of equipment, the complexity of measurements, the error of measurement, false decision, and difficulties in analysis. Therefore,
based in part on conventional studies concerning corrosion and cathodic protection monitoring, this study has been focused on the corrosion properties and the effect of cathodic protection in reinforced concrete with the use of zinc mesh sacrificial anode. Monitoring sensor was developed for accurate measurements, analysis, and diagnosis of corrosion and protection of reinforced concrete. In addition, the experiment has been chiefly concentrated on the possibility of commercialization of sacrificial anode cathodic protection system by
using monitoring sensor.
Reinforced concrete pile specimen was manufactured in order to obtain data related to the cathodic protection of marine piers and beams.
It was confirmed that the cathodic prevention system and cathodic protection systems with zinc-mesh sacrificial anodes were very effective at preventing rebar corrosion in concrete structures in marine environments.
Since there are limitations to obtaining accurate cathodic protection current density and degree of depolarization measurements from outside of reinforced concrete structures, the embedded sensors installed near the rebar at any specific location may be able to monitor the precise protection behaviors.
Autopsy results agree well with the results of the electrochemical measurements in terms of the effectiveness of the CP systems. From the coring sample inspection, in case that cathodic protection was applied, surface condition of rebar inside of specimen was generally
good compared to non-cathodically protected specimen. Better protection effects were confirmed in the specimen that was applied to the cathodic prevention than the cathodic protection.
Compared to the other studies, we have confirmed that the cathodic prevention was more effective than cathodic protection. It meant that cathodic prevention was very useful technique to increase the efficiency of cathodic protection and to extend the service life of reinforced concrete structures.