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  

Monitoring and Evaluation of Corrosion-induced Expansion in the Reinforced Concrete Structures: The Applications of Fiber Optic Low Coherent Strain Sensors

作　　者：魏鹤鸣[1] 张平磊[1] 崔砚军[2] 赵雪峰[2] 孙长森[1] 

机构地区：[1]大连理工大学物理与光电工程学院,辽宁大连116024 [2]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024

出　　处：《应用基础与工程科学学报》2014年第3期556-565,共10页Journal of Basic Science and Engineering

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)

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.A method based on a low coherent fiber-optic strain sensor （LCFS）was proposed for monitoring steel corrosion process in reinforced concrete specimens. This method employed a sensing fiber,which is circled on the steel bar embeded in the reinforced concrete structure to be monitored, to measure the expansion caused by corrosion and reflect the corrosion process. The expansion was measured by the Michelson interferometer and could measure the deformation in an arbitrary length of the sensing fiber with 5 micrometers resolution. In order to compare the Brillouin Optical Time Domain Analysis （BOTDA）distributed sensor with the low coherent sensor in the same specimen of the test, the electrochemical accelerating corrosion experiments were carried out in the simulated ocean environment. The results demonstrated that BOTDA sensors had an advantage in multipoint measurements, but the more corrosion progresses, the weaker signal could be detected. The measured upper-limited strain based on the 18mm-diameter steel bar was about 1000 με. This formed a limitation for the long-life structure monitoring. However, the LCFS had a high sensitivity in the whole life of the structure. This provided a potential method for study the steel corrosion process in the reinforced concrete structure, especially in experimental environment.

关 键 词：钢筋混凝土耐久性监测 锈蚀诱导膨胀应变 低相干光纤应变传感器 BOTDA分布式光纤传感器 

分 类 号：TU375[建筑科学—结构工程]