Review of fiber optic sensors for corrosion monitoring in reinforced concrete

Monitoring corrosion in reinforced concrete is critical to assess the health condition of structures at an early stage and enable effective and efficient asset management. Various novel fiber optic sensors have been developed and demonstrated many advantages in monitoring corrosion in reinforced concrete under different conditions. However, currently, there is a gap between sensor technology innovation and engineering practices, and the gap hinders further development and wide applications of fiber optic sensors. This paper reviews representative types of fiber optic sensors for monitoring corrosion in reinforced concrete. The reviewed types of sensors include grating sensors, interferometer sensors, distributed sensors, and reflectometer sensors. For each type of sensors, the reviewed contents include the sensing principle and key features of applications, such as sensor design and installation, sensitivity, resolution, and sensor life. Emphasis is placed on discussing the functions and performance of the sensors in different corrosion stages. Based on the review, technical challenges and future research needs are identified and discussed. This review is expected to advance sensor development and promote effective applications of fiber optic sensors for intelligent structures and asset management.