Performance of embedded short-gage-length optical fiber sensors in a fatigue-loaded reinforced concrete specimen

This paper reports the performance of short-gage-length optical fiber sensors embedded in a reinforced concrete specimen. Embedded extrinsic Fabry-Perot optical fiber sensors, attached to steel reinforcement rods, were used to monitor local displacements and strain in a concrete cross-beam specimen. The strain data obtained from the fiber sensors were compared with data obtained from collocated foil strain gages. Absolute extrinsic Fabry-Perot interferometric sensors, capable of measuring absolute displacement and strain, were embedded in a steel-reinforced concrete specimen. Loading experiments performed on this specimen also yielded absolute strain information. The specimen was cyclically loaded for more than 100000 cycles in this geometry and the sensors still provided quantitative strain information regarding this specimen.