Corrosion Monitoring Techniques In Reinforced Concrete And Numerical Analysis Of Corrosion Damage

Corrosion is the most important factor that leads to reliability deterioration of steel reinforced concrete structures. However, traditional corrosion monitoring techniques confined with some disadvantages, such as, lower reliability, poor anti-interference ability, etc. are not suitable for the corrosion monitoring in long term. The fiber optic is ideal sensing element for long-term monitoring, it has superior durability, high stability, electromagnetic interference immunity, multi-parameter distribution measurement, etc. Thus, the fiber optic get more attention in structural health monitoring sensor technology in recent years.In this paper, making full use of the advantages of optical fiber,the following work is done:(1) A kind of the concrete package uniform corrosion sensor is developed, which is based on the fiber optic white light Michelson interferometer(WLI). The sensing technology of the sensor with protective layer of mortar between the fiber coil and the reinforced is reseatched. The sensing performances of the sensor are studied by the electrochemical accelerating corrosion test in the laboratory.(2) In order to monitor non-uniform corrosion of the reinforced, a kind of the concrete package non-uniform corrosion sensor is developed, which is based on the fiber optic white light Michelson interferometer. The sensing performances of the sensor are studied by the electrochemical accelerating corrosion test in the laboratory.(3) In order to monitor striker depassivation surface depth caused by the chloride ion erosion or carbonation on the side of concrete protection layer, a kind of the concrete package striker depassivation surface depth sensor is developed, which is based on BOTDA sensing technology. The sensing performances of the sensor are studied by the electrochemical accelerating corrosion test in the laboratory.(4) The concrete cover cracking caused by the reinforced corrosion is simulated and analyzed based on ABAQUS finite element analysis software, and get the trend of concrete cracking.The experimental studies have shown the corresponding corrosion strain measurement is realized by uniform corrosion sensor based on WLI, non-uniform corrosion sensor based on WLI and striker depassivation surface depth sensor based on BOTDA, the precise strain is obtained. The performance of the three sensors are summarized and evaluated, the test evaluation and research results show that the Three sensors can be applied to practical engineering.