氯盐引起的钢筋混凝土锈胀开裂是影响结构耐久性的主要病害之一，对锈胀开裂进行全过程监测是评估结构的剩余使用寿命和做出维修决策的关键。分布式光纤传感技术是一种新型光电监测技术，可实现腐蚀环境下的应变、温度的长距离分布式检测，适用于钢筋混凝土锈胀开裂监测。本文基于钢筋混凝土锈胀开裂的力学原理，设计了钢筋混凝土锈胀开裂全过程的分布式光纤传感监测技术，通过内压加载模拟试验标定了光纤应变和混凝土膨胀、裂缝之间的对应关系，最后采用通电加速试验验证了本文提出方法的有效性。结果表明，分布式光纤传感技术能实时跟踪监测锈胀开裂全过程，监测数据可用于判断初始开裂发生的时间点，由标定试验获取的应变/裂缝系数可实现锈胀裂缝的宽度估算，为工程结构养护管理提供决策依据。%Expansion and cracking induced by chloride corrosion is one of the main deterioration issues affecting the durability of reinforced concrete.Monitoring the whole process of expansion and cracking acts as an important role for remaining service life evaluation and strategic repairing decision making. The distributed optical fiber sensing technology is a technique used for measuring of distributed strain and temperature;it is applicable for expansion and cracking monitoring of reinforced concrete in corrosive environment.In this paper,the mechanical mechanism of cor-rosion-induced expansion and cracking was illustrated.Using the above mechanism,a novel monitoring method based on distributed optical fiber sensor had been presented.The calibration experiment had been carried out to establish the relationship named strain/expansion ratio and strain/crack width ratio.The validity of proposed method was ap-proved by electricity accelerated corrosion experiment. The results shown that the novel monitoring method adopted in this paper was suitable for the whole expansion and cracking process detecting.The critical cracking moment and the cracking width could be estimated by analyzing monitored data.This novel monitoring method is helpful for infra-structure management department to make maintenance programming.
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