钢筋混凝土锈蚀诱导的膨胀监测及评估——低相干光纤应变传感器的应用

发布时间：2018-09-14 18:04

【摘要】：针对钢筋混凝土中锈蚀问题,提出了一种基于低相干光纤应变传感器的钢筋混凝土锈蚀进程监测方法,设计中将传感光纤环绕在待测结构易锈蚀部分,通过测量钢筋锈蚀诱导膨胀所造成的结构微形变来反映其锈蚀进程.基于Michelson干涉仪的信号解调方法可以测得任意长传感光纤上5μm的绝对形变.将布里渊分布式传感器和低相干光纤应变传感器布置在同一钢筋混凝土试件结构中,进行模拟海洋环境的电化学加速锈蚀实验.结果表明,分布式传感器在多点测量方面有优势,但其信号强度在锈蚀的后期衰减较快,在18mm钢筋直径的锈蚀实验中测得的上限锈胀应变为1000με,这难以满足结构耐久性监测的需要.而低相干光纤应变传感器可以长寿命测量出锈蚀的产生及发展,根据这些实验数据对钢筋混凝土的锈蚀膨胀应变与结构性能作了相关分析,为钢筋混凝土结构的耐久性监测提供了一种可行的实验室研究手段.
[Abstract]:Aiming at the problem of corrosion in reinforced concrete, a method for monitoring the corrosion process of reinforced concrete based on low coherent fiber strain sensor is proposed. The sensing fiber is surrounded by the susceptible part of the structure to be tested in the design. The structural microdeformation caused by corrosion induced expansion of steel bars was measured to reflect the corrosion process. The signal demodulation method based on Michelson interferometer can measure the absolute deformation of 5 渭 m on any length sensing fiber. Brillouin distributed sensors and low coherent fiber optic strain sensors were arranged in the same reinforced concrete specimen structure and electrochemical accelerated corrosion experiments were carried out to simulate the marine environment. The results show that the distributed sensor has advantages in multi-point measurement, but its signal intensity attenuates rapidly in the later stage of corrosion. The upper corrosion strain measured in the corrosion test of 18mm steel bar diameter is 1000 渭蔚, which is difficult to meet the needs of structural durability monitoring. The low coherent fiber strain sensor can measure the occurrence and development of corrosion in long life. Based on these experimental data, the corrosion expansion strain and structural properties of reinforced concrete are analyzed. It provides a feasible laboratory method for durability monitoring of reinforced concrete structures.
【作者单位】：大连理工大学物理与光电工程学院;大连理工大学海岸和近海工程国家重点实验室;
【基金】：国家自然科学基金面上项目(51278085) 中央高校基本科研业务费专项资金支持项目(DUT12LAB15) 大连市科技计划项目(200700368)
【分类号】：TU375

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