Application of clad/unclad optical fiber in the corrosion studies of reinforced concrete rebars

Abstract

Application of reinforced concrete structures is to be very long-lasting and capable of enduring a variety of environmental conditions. Reinforced concrete is generally a combination of steel and concrete which provides an interwoven withstanding feature in compressive and tensile strength. Even then, undesirable corrosion failures in the structures still take place and cause lots of physical and economical losses. Traditionally, visual observation and electrochemical techniques have been used to measure electrochemical corrosion. In this project a Fiber Bragg Grating sensor (FBG) was used to monitor the concrete structures containing reinforcement rebar. Two samples for two different environments were investigated and results were reported. Since corrosion reaction is a low-speed reaction which takes a lot of time to initiate in order to accelerate this reaction, test was performed in a salt saturated solution at a constant temperature for 10 days and afterward an flow current of 0.2 A was applied. At the end the effectiveness of FBG sensor was evaluated as a capable device for corrosion monitoring of the mild steel rebars used as reinforcement in concrete structures.