【摘要】 对带氧化皮钢筋和带锈钢筋以及裸表面钢筋进行了电化学试验,研究不同表面的钢筋在模拟混凝土溶液[饱和Ca(OH)2溶液]中的腐蚀行为及钝化规律。结果表明,对于稳定后的自腐蚀电位,裸表面钢筋最高,带氧化皮表面钢筋次之,带锈表面最低;随着pH的降低,三种表面钢筋的钝化性能都随之降低,带氧化皮钢筋和裸表面钢筋的钝化能力明显高于带锈钢筋,测定了临界钝化pH,裸表面钢筋的临界钝化pH为11.2,带氧化皮钢筋的为11.0,而带锈钢筋的临界钝化pH为12.4,说明在pH降低的情况下,当带锈钢筋开始发生腐蚀时,裸表面钢筋和带氧化皮钢筋依旧可以保持钝化;随着氯离子浓度升高,带氧化皮表面钢筋和裸表面钢筋钝化性能都随之降低,测定的临界钝化浓度也大致相同,为0.03mol/L,极小量氯离子浓度即可导致带锈钢筋去钝化,临界值为0.01mol/L。更多还原

【Abstract】 Electrochemical experiments were used to study the passivation behavior of the steel rebars with polished surface,oxide skin and rusty skin in simulated concrete pore solution.The results indicated that after the corrosion potential became stable,the steel rebar with nude surface had the highest potential while the steel rebar with rusty skin had the lowest potential.With the decrease of solutions’ pH value,the passivation of the three kinds of rebar decreased.The passivation of nude surface steel rebar and oxide skin rebar was apparently better than that of rusty skin rebar.The threshold pH values for polished steel rebar,oxide skin rebar and rusty skin rebar were 11.2,11.0and 12.4,respectively.With the increase of chloride ion concentration,the passivation property of the three kinds of rebar decreased.The passivation of rusty rebar was apparently worse than that of nude surface rebar and oxide skin rebar.The threshold of chloride ion concentration for polished steel rebar,oxide skin rebar and rusty skin rebar were0.03mol/L,0.03mol/L and 0.01mol/L,respectively.更多还原