Research On The Influence Of Concrete Pore Water Saturation On Stray Current Corrosion Of Reinforced Concrete Structure

Influenced by environmental factors,the rail structure is aging and damaged,which will cause part of the current to leak from the running rail to form a stray current.At the same time,environmental humidity will lead to the change of pore water saturation of concrete structure.In the coupled environment of stray current and pore water saturation,it will aggravate the corrosion of reinforced concrete structure,shorten its service life,and then endanger the normal operation of subway.Therefore,based on the stray current corrosion of reinforced concrete structures,combined with the factors of concrete pore water saturation,a research model of concrete pore water saturation on the corrosion of reinforced concrete structures under the influence of stray current is established,and the influence law of pore water saturation on each stage of stray current corrosion of reinforced concrete structure is analyzed.The research involves the influence of factors such as concrete porosity and stray current on the corrosion process of reinforced concrete structures with the change of pore water saturation.The research contents mainly include:（1）By analyzing the formation mechanism of subway stray current,the stray current distribution model of track-reinforced concrete structure is established,and the analytical formula of stray current is deduced.（2）Study the influence factors of concrete pore water saturation by analyzing the characteristics of reinforced concrete structure.Combining with the control methods of the stray current corrosion of reinforced concrete structures at each stage,the quantitative relationship between porosity,oxygen diffusion coefficient,electrical conductivity and pore water saturation are deduced,and a kinetic model of the influence of concrete pore water saturation on the stray current corrosion process of reinforced concrete structures is establish.（3）Establishing a stray current corrosion model of track-reinforced concrete structure by using COMSOL software.Combined with the mathematical analysis model,the simulation analysis of the influence of pore water saturation on the electrochemical corrosion of reinforced concrete structures is carried out.The results show that the porosity does not affect the pore water saturation control range corresponding to each stage of the stray current corrosion process.The greater the porosity of the specimen under the same voltage condition,the more severe the corrosion of the reinforced concrete structure will be with the increase of the pore water saturation;The pore water saturation affects the control method of each stage of electrochemical corrosion of the reinforced concrete structures,and the control range of pore water saturation corresponding to the corrosion stage under each control mode shows a trend of shrinking,shifting left and expanding as the applied voltage increases.（4）Based on the simulation results,set up a simulation experiment of the effect of concrete pore water saturation on the corrosion of reinforced concrete structures under the influence of stray currents.Through the processing of experimental data and the comparison of simulation results,the influence of concrete porosity and voltage value on the control range of pore water saturation corresponding to each stage of stray current corrosion of reinforced concrete structure is verified.There are 38 figures,4 tables,and 92 references in this thesis.