关键词: 地铁用混凝土;复合盐溶液;电化学腐蚀;电化学参数;微观结构

Abstract: In order to study the corrosion resistance of reinforced concrete in Lanzhou subway , the corrosion solution of 5000 mg/L Mg2 SO4 and 2000 mg/L NaCl was prepared according to the corrosive ion concentration of groundwater and underground soil in Lanzhou , and the concrete was designed with ratio of water to cement as 0.25, 0.35 and 0.45, respectively.Then continuous immersion corrosion test was carried out indoor .Electrochemical method was used to study the corrosion of steel bars in concrete .The corrosion of reinforced concrete in groundwater and underground soil environment in Lanzhou was investigated through electrochemical parameters comparison , theoretical analysis and microstructure results.The results show that the reinforced concrete is prone to corrosion in the strong corrosive groundwater and underground soil environment of Lanzhou .The reinforced concrete has the best corrosion resistance when the ratio of water to cement is set to 0.35 after comparison of the test results .Also, as the corrosion time increases , the corrosion of reinforced concrete showes an increasing trend , although it decreases in the early stage .

Key words: subway concrete;composite salt solution;electrochemical corrosion;electrochemical parameters;microstructure