Abstract: Steel corrosion is becoming the main factor that affects the durability of reinforced concrete structures. The volume expansion of steel bar after corrosion causes the cover to crack gradually, which reduces structure performance and affects structural durability. Based on the corrosion expansion principle of steel bars in reinforced concrete structures and the principle of fiber grating strain sensing technology, a new corrosion monitoring device for steel bars is proposed and designed. According to the relationship between FBG wavelength and corrosion rate of steel bar, reinforced concrete specimens were made and accelerated test was carried out. Finally, ABAQUS finite element software is used to carry out numerical simulation with the experimental results, and the simulation results are in good agreement with the test results. The test results show that the new steel corrosion sensor can effectively monitor the corrosion degree of steel bars and realize the whole process monitoring of concrete cover cracking.

Key words: steel corrosion, structural durability, fiber grating sensing technology, whole process monitoring