Development of Fe-C film coated polymer optical fiber sensor for steel bar corrosion monitoring

Abstract

Corrosion detection is one of the most important studies in structural health monitoring systems (SHM) for reinforced concrete structures such as bridges. Due to the high initial investment and technical limitations of conventional technology, SHM systems are mostly deployed in the existing mega-scaled bridge infrastructures. This work demonstrates a novel nondestructive method using Fe-C film-coated polymer optical fiber sensor for steel bar corrosion monitoring. The sensing performance of the proposed sensors was investigated in the simulated corrosion test. The results showed that the sensors with different thicknesses of Fe-C film shared similar output curve characteristics but different sensitivities to the same corrosion state. The sensors embedded in the mortar specimens with the reinforced structure were then evaluated under the accelerated corrosion condition. The results indicated that the output signals of sensors were in agreement with that of the earlier experiment, and the thinner Fe-C film showed higher sensitivity to corrosion.