对氯盐污染混凝土进行电化学除盐时阴极附近产生的气体进行收集与分析,研究了电化学除盐时钢筋表面发生的电极反应。结果表明:在电化学除盐前期钢筋表面析氢和耗氧反应同时存在,在氧气消耗到一定程度后,电极反应主要为析氢反应。析氢反应主要取决于电流密度,氢气的生成常数κH2与电流密度I存在线性关系κH2=5.36×10^-8 I—1.99×10^-8;耗氧反应则在除盐早期决定于电流密度,而后期则取决于O2扩散到混凝土表面的速率。
By collection and analysis of the gas formed in the vicinity of the cathode, the electrode reaction on the steel surface of reinforcement material during electrochemical chloride extraction (ECE) was studied. The results show that hydrogen gas evolution reaction and oxygen gas consumption reaction occur on the surface of the reinforcement material during the early stage of ECE, and the hydrogen gas evolution reaction becomes dominant when oxygen gas is consumed to some extent. The hydrogen gas evolution reaction is mainly dependent on the electrical current density, and the constant of hydrogen gas generation kH2 has a linear relationship with electrical current density I as κH2=5.36×10^-8 I-1.99×10^-8. The oxygen gas consumption reaction is greatly varies with electrical current density during the early stage of ECE, and with the diffusion rate of oxygen gas towards the surface of concrete during the late stage of ECE.