Temperature Control Measurement of Bridge Foundation Concrete based on the Optical Fiber Sensing Technology

Temperature monitoring is an important component of structural health monitoring of mass concrete after pouring. This study investigates temperature measurements of mass concrete based on Brillouin optical time-domain analysis (BOTDA). First, the fundamental principle of using BOTDA-based distributed optical fiber sensing (DOFS) technology to measure temperatures is provided. Then, a temperature-measuring system is introduced. Finally, a case study on an engineering structure was conducted to explore issues relating to the practical application of BOTDA-based DOFS technology, including optical fiber cable laying and protection, measurement and results analysis. In addition, point temperature sensors and precision thermometers were used to measure the temperatures at several points along the optical fiber cable and the ambient temperature, respectively. The measurement results were compared with those measured by the optical fiber cable. Our study shows that BOTDA-based DOFS technology can be used to take accurate distributed temperature measurements of mass concrete structures. This temperature-measuring method provides an effective means for measuring the temperature of mass concrete structures.