不同腐蚀环境下钢筋腐蚀的电化学研究  

Steel corrosion electrochemical research under the condition of wet and dry cycle

作　　者：杨莉[1] 金祖权[1] 张慧[1] 

机构地区：[1]青岛理工大学土木学院,山东青岛266033

出　　处：《混凝土》2014年第5期27-29,34,共4页Concrete

基　　金：国家自然科学基金项目(50708046;51178230);铁道部科技研究计划(2010G024)

摘　　要：海洋环境下混凝土中钢筋锈蚀是导致结构破坏的主要原因,研究了钢筋在不同pH值、不同腐蚀模拟溶液中以及带钢筋的水泥净浆、砂浆在氯盐硫酸盐复合溶液和海水干湿循环作用下的电化学行为。试验结果表明:干湿循环初期,钢筋电化学阻抗谱为半径很大的容抗弧,钢筋处于钝化状态。随着干湿循环次数增加,钢筋阻抗谱表现为双容抗弧,容抗弧半径发生收缩,极化电阻越来越小,腐蚀电流密度增加,钢筋锈蚀速率加快。钢筋腐蚀的临界氯离子浓度随着pH值的减小而减小;对于砂浆而言,其护筋能力强于净浆,并且相比于海水腐蚀,砂浆在复合溶液中的钢筋腐蚀速率较小。Steel corrosion in concrete is a major cause of structural damage under the Marine environment.The article studies the elec- trochemical behavior of the steel at different pH value, different corrosion simulation solution and cement past and mortar with steel in chloride sulfate complex solution and seawater under wet and dry cycles.The experimental results showed that reinforced electrochemical impedance spectroscopy for capacitive are large radius in initial stage of wet and dry cycles, steel was in passivation state.With the increas- ing number of dry-wet cycle, reinforced impedance spectroscopy shows double capacitance, capacitance arc radius of capacitance shrunk, the polarization resistance was smaller and smaller, But the corrosion current density and corrosion rate were gradually increasing.with the PH value decreasing, The critical chloride concentration of steel decreased.Mortat＇s capacity of protective bar is stronger than paste.Compared to the seawater corrosion, the corrosion rate of the mortar reinforced in the composite solution is smaller.

关 键 词：砂浆 钢筋 临界氯离子浓度 电化学特性 干湿循环 

分 类 号：TU528.01[建筑科学—建筑技术科学]