Applications of optical fiber sensor in pavement Engineering: A review

Optical fiber sensor (OFS) is a commonly used tool to monitor the serviceability and integrity of pavements. The earliest application of optical fiber sensors in the road can be traced back to the early 21st century, and development of this technique has been extensively studied after that. In view of the increasing demand for pavement nondestructive testing and the rapid development of optical fiber sensor technology, this work summarizes the optical fiber sensors commonly used in road engineering and the classification methodologies. After that, the basic principle of fiber Bragg grating (FBG) sensor and the application of this sensor in the pavement were discussed. Finally, the principle and application of distributed optical fiber sensors (DOFS) in the pavement were included as well. Overall, this review found that FBG sensors can accurately measure and monitor road strain, temperature, pressure and WIM measurement by employing analytical-based methods. Distributed optical fiber sensors can measure pavement crack width, identify the void under the concrete slab, and obtain vehicle load (load size, load moving speed, axle type) and other data. Currently, it has been proved that the installation of the installation of fiber optic sensors on the road surface is an effective method to monitor the integrity of the road structure under traffic, but further tests in real traffic environment to further improve the survival rate of fiber optic sensors and evaluate the accuracy of the measured results are still needed.