Incorporation of fiber-optic sensors in concrete specimens: testing and evaluation

As series of tests has been carried out on the performance of several fiber-optic temperature sensors, operating on the fluorescence lifetime principle using neodymium-doped fiber and configured into ruggedized temperature probes, mounted in a number of different concrete samples. The aim has been to evaluate the performance of probes fitted into concrete specimens to simulate the conditions experienced in structures used in civil applications, such as bridges and dams. A key feature of the investigation was observing the integrity of the sensors under investigation while obtaining temperature data from the device. The results show the sensors operated well from below room temperature to beyond 300/spl deg/C, preserving their integrity under adverse test conditions.