Fiber Bragg Grating Sensors for Breaking Tests in Reinforced Concrete Structures Strengthened with Embedded Composite Bars

In this work, the use of fiber optic sensor (FOS) based on fiber Bragg gratings (FBGs) to measure strain in civil structures is examined. In particular, the optical system has been bonded on a carbon fiber bar embedded in a reinforced concrete (RC) beam subjected to bending test. For the interrogation system of these sensors, a robust and costly competitive passive technique is here adopted. Experimental results and comparison with displacement transducers show how FBGs offer an excellent tool for embedded monitoring