In recent years, the rapid development of economy and the huge scale of infrastructure construction have made concrete materials widely used in various fields such as civil, industrial, and transportation. Many cities have accelerated the construction of urban rail transit because of the large passenger volume, fast, convenient and safe characteristics of railway passenger traffic1. The current on the track would leak into the track bed and surrounding soil media while the subway was running. Direct current would severely corrode the steel bars in nearby concrete structures. As the use time of the reinforced concrete structure increased, external factors such as chloride ion corrosion and concrete carbonization would also cause the bearing capacity and ductility of the reinforced concrete structure to decrease. In severe cases, the building would be damaged and caused huge losses.Aeronautical Engineering Institute of Civil Aviation University of China Researchers Qingmiao Ding, Yuning Gao, Ruiyang Liu & Yaozhi Li; China National Offshore Oil Corporation’s Tianjin Pipeline Engineering Technology Co’s Lei Jin & Jiangsu Shagang Group’s Han Ma have published a paper on “Corrosion behavior of HRB400 and HRB400M steel bars in concrete under DC interference” in Nature, where they stuuudied influence of direct current interference on the corrosion behavior of HRB400 and HRB400M steel bars in simulated concrete solution was studied using methods such as weight loss experiment, electrochemical experiment, surface technology and product analysis. The rapid development of high-voltage transmission lines and electrified railways has made the problem of stray current corrosion more prominent15. Stray current corrosion was divided into DC stray current corrosion and AC stray current corrosion16. Metros and light rails mostly used 750 V or 1500 V DC electric traction systems and track return methods in China. In order to explore the applicability of corrosion-resistant steel bars in the complex concrete environment of airports, this paper used weightlessness experiment, electrochemical experiment, surface technology, product analysis and other methods to study the influence of DC stray current on the concrete reinforcement in the later stage of carbonization. The influence of DC stray current on the corrosion behavior of HRB400 and HRB400M steel in simulated concrete solution was obtained. By comparing the experimental data of the two materials, the specific degree of corrosion resistance was analyzed in order to provide a certain reference for the wide application of corrosion-resistant steel bars in the airports.The research results showed that with the increase of DC interference voltage, the corrosion rates of HRB400 and HRB400M steel bars would increase. The corrosion resistance of HRB400M steel bars was better than HRB400 steel bars under the experimental conditions. In addition, direct current interference could cause damage to the corrosion product layer on the surface of HRB400 steel bars and HRB400M steel bars. And the corrosion form and corrosion product types of HRB400 and HRB400M steel bars would be affected by direct current interference. The main corrosion products of HRB400 steel bars included γ-FeOOH and Fe2O3 when it was not interfered by DC. When DC interference was applied, the main corrosion products included Fe3O4 and Fe2O3. The corrosion products on the surface of HRB400M steel bars were mainly Fe3O4 and Fe2O3, and the types of products increased to form Cr2O3 and MnFe2O4.
In recent years, the rapid development of economy and the huge scale of infrastructure construction have made concrete materials widely used in various fields such as civil, industrial, and transportation. Many cities have accelerated the construction of urban rail transit because of the large passenger volume, fast, convenient and safe characteristics of railway passenger traffic1. The current on the track would leak into the track bed and surrounding soil media while the subway was running. Direct current would severely corrode the steel bars in nearby concrete structures. As the use time of the reinforced concrete structure increased, external factors such as chloride ion corrosion and concrete carbonization would also cause the bearing capacity and ductility of the reinforced concrete structure to decrease. In severe cases, the building would be damaged and caused huge losses.Aeronautical Engineering Institute of Civil Aviation University of China Researchers Qingmiao Ding, Yuning Gao, Ruiyang Liu & Yaozhi Li; China National Offshore Oil Corporation’s Tianjin Pipeline Engineering Technology Co’s Lei Jin & Jiangsu Shagang Group’s Han Ma have published a paper on “Corrosion behavior of HRB400 and HRB400M steel bars in concrete under DC interference” in Nature, where they stuuudied influence of direct current interference on the corrosion behavior of HRB400 and HRB400M steel bars in simulated concrete solution was studied using methods such as weight loss experiment, electrochemical experiment, surface technology and product analysis. The rapid development of high-voltage transmission lines and electrified railways has made the problem of stray current corrosion more prominent15. Stray current corrosion was divided into DC stray current corrosion and AC stray current corrosion16. Metros and light rails mostly used 750 V or 1500 V DC electric traction systems and track return methods in China. In order to explore the applicability of corrosion-resistant steel bars in the complex concrete environment of airports, this paper used weightlessness experiment, electrochemical experiment, surface technology, product analysis and other methods to study the influence of DC stray current on the concrete reinforcement in the later stage of carbonization. The influence of DC stray current on the corrosion behavior of HRB400 and HRB400M steel in simulated concrete solution was obtained. By comparing the experimental data of the two materials, the specific degree of corrosion resistance was analyzed in order to provide a certain reference for the wide application of corrosion-resistant steel bars in the airports.The research results showed that with the increase of DC interference voltage, the corrosion rates of HRB400 and HRB400M steel bars would increase. The corrosion resistance of HRB400M steel bars was better than HRB400 steel bars under the experimental conditions. In addition, direct current interference could cause damage to the corrosion product layer on the surface of HRB400 steel bars and HRB400M steel bars. And the corrosion form and corrosion product types of HRB400 and HRB400M steel bars would be affected by direct current interference. The main corrosion products of HRB400 steel bars included γ-FeOOH and Fe2O3 when it was not interfered by DC. When DC interference was applied, the main corrosion products included Fe3O4 and Fe2O3. The corrosion products on the surface of HRB400M steel bars were mainly Fe3O4 and Fe2O3, and the types of products increased to form Cr2O3 and MnFe2O4.
