Numerical Simulation Of Subway Stray Current Field And Experimental Study Of Its Effect On Steel Corrosion In Concrete

Based on the stray current of subway,this paper discusses the effect of stray current on the corrosion of reinforced concrete structures.Firstly,the mathematical model of stray current leakage in metro track is established by using Kirchhoff's voltage and current law.The leakage behavior of the stray current of the subway track is simulated by COMSOL finite element simulation software,and the stray current distribution along the track is obtained.Based on this,COMSOL is used to simulate the distribution and inflow and outflow behavior of current in the concrete structure in the stray current field.Secondly,the stray current signal on the subway side collected on site is used as the signal source to carry out stray current energization to accelerate the steel corrosion test.At the same time,the DC current of the same amount of charge accelerates the corrosion test of the steel bar,and compares the corrosion behavior of the steel bars under the two energization modes.Thirdly,the whole process tracking of the corrosion behavior of steel bars in cement mortar was carried out by XCT technology.The 3D reconstruction and reduction of XCT image data was performed by Avizo 3D visualization software,and the volume and area calculations were carried out.In addition,by calculating the mass loss,the similarities and differences between stray current energization and DC current current efficiency are compared.Finally,based on the simulation model of stray current distribution in reinforced concrete structure and the results of stray current energization to accelerate the corrosion test of steel reinforcement,the calculation model of the corrosion amount of concrete structure reinforcement under the stray current field environment is established.According to the calculation model of corrosion amount,the corrosion of concrete structure in stray current field is predicted.