Experimental Study Of Bridge Internal Reinforcement Corrosion Degree Based On Electromagnetic Pulsed Eddy Current

With the application and development of the reinforced concrete structure, its durability becomes the spotlight. The reinforcement corrosion in the structure is the most serious durability failure mode and also the main cause of the reinforced concrete bridge damage. Therefore, for the reinforced concrete bridge, it is particularly important to detect the reinforcement corrosion on a regular basis. The existing detection techniques mainly include the damage detection technique, half damage technique and nondestructive detection technique. The pulsed eddy current detection researched in this paper belongs to the nondestructive detection technique and becomes a kind of efficient nondestructive detection method for the reinforced concrete structure, which has the advantages of safety, low cost, no shutdown, not being embed, no destroying concrete cover. In this paper, based on the principle of electromagnetic pulse eddy current, a set of detection system has been designed. Meanwhile, based on electromagnetic pulse eddy current, magnetic field simulation by ANSYS software and experimental study on the bridge internal reinforcement corrosion degree have been completed. In conclusion, the paper has tried to explore a new method for reinforcement corrosion degree detection. Main research contents and conclusions in the paper include the following points:① Based on the analysis of the working principle of pulsed eddy current, skin effect, infiltration depth and several important parameters influencing induced voltage, a set of electromagnetic pulse eddy current detection system has been designed and the technical indicators and functional properties of components in the system has been introduced.② The corrosion of reinforcement electromagnetic pulse eddy current test was completed. The test results show that under the existing experimental conditions, the detection system is only within a certain distance range can effectively detect the defect position. What is more, the stronger and the wider the corrosion defects, the induction voltage amplitude will be smaller, as same as the induction voltage amplitude and pulse rising time. So the system can not only detect the defect position, also can distinguish the size of the defect, which proved that the system is feasible. At the same time the system can effectively detect the reinforced location and the size of the steel bar diameter.③ The pulsed eddy detection test of different diameter rebars embed in concrete was completed. The rebars were corroded respectively with the method of artificial simulation and electrochemical corrosion. The reinforced concrete blocks with different corrosion degree were detected by the testing system. The test results show that the testing results between reinforced concrete block and the bare steel have the same rule.④ The finite element analysis software(ANSYS) simulation analysis was completed. Firstly, a brief introduction about electromagnetic field finite element analysis was made. Then, the modeling and simulation of reinforcement corrosion degree in concrete member was done. The simulation results of rebars under different corrosion degrees covered by a certain thickness of concrete cover were extracted and follow-up results were analyzed, which were consistent with the experimental results.Therefore, the research of the bridge internal degree of reinforcement corrosion detection method this article explored is effective and feasible,which based on the technology of electromagnetic pulse eddy current, and the method is easy to operate and has reliable results. It has a certain application prospect.