A fiber optic sensor for detecting and monitoring cracks in concrete structures  

作　　者：BAO TengFei WANG JiaLin YAO Yuan 

机构地区：[1]State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210024,China [2]National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety,Hohai University,Nanjing 210024,China

出　　处：《Science China(Technological Sciences)》2010年第11期3045-3050,共6页中国科学(技术科学英文版)

基　　金：supported by the National Natural Science Foundation of China (Grant Nos 50909041, 50539110, 50809025, 50879024);National Science and Technology Support Plan (Grant Nos 2008BAB29B03, 2008BAB29B06);China Hydropower Engineering Consulting Group Co Science and Technology Support Project (Grant No CHC-KJ-2007-02);Jiangsu Province "333 High-Level Personnel Training Project" (Grant No 2017-B08037);Science Foundation for the Excellent Youth Scholars of Minis-try of Education of China (Grant No 20070294023);the Special Fund of State Key Laboratory of China (Grant No 2009586012);the Fundamental Research Funds for the Central Universities (Grant No 2009B08514)

摘　　要：The formation and propagation of cracks reflect the aging and pathologic changes of concrete structures and may cause problems such as seepage and long-term durability. Crack detection and monitoring is therefore an effective way to evaluate structural health conditions. An important challenge in such a task is that the locations and orientations of cracks in concrete structures are difficult to predict due to material inhomogeneity and complexity. The number of the required conventional electric and electromagnetic sensors to cover all possible cracks may be too large to be practical for a monitoring scheme. In this paper, a fiber optic sensor with distributed crack sensing capability based on optical time domain reflectometry is proposed and its sensing principle is introduced. Experiments are conducted to obtain the optical power loss versus crack opening at different fiber inclination angles, and then a model is developed to quantify it. Finally, an experiment is performed to demonstrate the practical application of the sensor. The test results show that detecting and monitoring cracks with the sensor do not require a-priori knowledge of crack locations and orientations.The formation and propagation of cracks reflect the aging and pathologic changes of concrete structures and may cause problems such as seepage and long-term durability. Crack detection and monitoring is therefore an effective way to evaluate structural health conditions. An important challenge in such a task is that the locations and orientations of cracks in concrete structures are difficult to predict due to material inhomogeneity and complexity. The number of the required conventional electric and electromagnetic sensors to cover all possible cracks may be too large to be practical for a monitoring scheme. In this paper, a fiber optic sensor with distributed crack sensing capability based on optical time domain reflectometry is proposed and its sensing principle is introduced. Experiments are conducted to obtain the optical power loss versus crack opening at different fiber inclination angles, and then a model is developed to quantify it. Finally, an experiment is performed to demonstrate the practical application of the sensor. The test results show that detecting and monitoring cracks with the sensor do not require a-priori knowledge of crack locations and orientations.

关 键 词：fiber optic sensor CRACK CONCRETE 

分 类 号：TU746.3[建筑科学—建筑技术科学]