Corrosion Of Coated Steel Bars In Salt Spray Environment Study Of Sexual Behavior

In Northwest China,the climate is dry and transpiration is strong.The migration of inland rivers not only intensifies soil salinization,but also promotes the evolution of inland lakes to salt lakes.As a result of the continuous erosion of the salt spray of the salt lake and the salt in the soil,the steel bars in the building structure have severely corroded to the buildings and structures in the area,and the buildings and structures generally cannot reach their service life.In response to this problem,this article is funded by the National Natural Science Foundation of China(Key Technology Research on Magnesium Oxychloride Cement Reinforced Concrete in Qinghai Salt Lake Area,project number: 51868044)to design a salt spray test and conduct a test on bare steel bars and coated steel bars.Accelerate the corrosion,determine the relevant parameters through electrochemical tests,analyze the changes of the parameters,and explore the corrosive behavior of the steel bar specimens in the salt spray environment.And using the incremental change relationship of different parameters,the Wiener process and the unary linear regression were used to establish the failure comparison model of the coated steel bars to determine the parameters and model methods suitable for establishing the failure model of the coated steel bars.Main research contents of this paper:(1)Selection of a regional representative of chlorine salt,sulfate and chloride salt-coupled sulfate solution,using the salt fog box,electrochemical devices,such as,salt fog test was carried out on the bar in order to achieve the purpose of accelerating corrosion,and the salt spray test can be determined through electrochemical non-destructive testing methods under different kinds and concentrations of salt in the process of reinforced the change of electrochemical parameters,for studying the rebar corrosion behavior.The results show that the protective effect of epoxy resin coating on reinforcement is better than that of asphalt coating in chlorine salt and chloride salt-sulfate coupled salt spray environment.Asphalt coatings exhibit better durability than epoxy coatings in sulfate spray environments.However,considering the thick and uncontrollable thickness of asphalt coating and the susceptibility to peeling and other reasons,in general,asphalt coating and epoxy resin coating have better protective effect on reinforcement in salt erosion environment,but epoxy resin coating has better working performance.(2)According to the corrosion current density results obtained from the electrochemical test,the corrosion of rebar is the most serious in the chlorine-sulfate corrosion environment,followed by the chlorine-sulfate corrosion environment,and the corrosion of rebar is the least in the sulfate erosion environment.The corrosion current density of exposed steel bars tends to be serious with the increase of chloride concentration.Salt spray test by adding a certain amount of sulfate solution into the chloride solution found that sulfate can play a corrosion inhibition effect,but in a single sulfate erosion environment,the steel bar will still have serious corrosion,the reason is that sulfate acts as an electrolyte to accelerate the effect of electrochemical corrosion.(3)By comparing the competitive failure models of coated steel bars,the results show that: when the electrochemical corrosion current density is selected as a parameter,the established linear regression model cannot accurately characterize the corrosion current density degradation relationship and does not meet the test conditions,while the reliability prediction model based on Wiener process has low accuracy.The reliability prediction model based on Wiener process has high accuracy and can accurately reflect the reliability degradation relationship when the quality degradation of steel bar is selected as the parameter,which can be used to compare the competitive failure models of coated steel bar.