Research on strain monitoring of RC girder using long-gauge strain sensors

A strain is an important index reflecting RC structural performance. However, the conventional method of measurement using resistance strain gauge has its own limitations. This paper introduces the advantages and measuring principle of long-gauge optical fiber-based strain sensors. In a box-girder loading test, two types of long-gauge optical fiber strain sensors were utilized. Comparing with resistance strain gauge measurements and theoretical results, the authors discussed linearity, measuring accuracy and range of three types of sensors. The results show that the long-gauge strain sensors are feasible and effective.