水气环境变化对混凝土中钢筋宏电池腐蚀的影响  

Influence of water-air environment change on macro-cell corrosion of reinforced steel in concrete

作　　者：曹忠露[1,2] 张文锋 李沛[1] CAO Zhong-lu;ZHANG Wen-feng;LI Pei(CCCC Tianjin Port Engineering Institute Co.,Ltd.,Tianjin 300222,China;CCCC First Harbor Engineering Co.,Ltd.,Tianjin 300461,China)

机构地区：[1]中交天津港湾工程研究院有限公司,天津300222 [2]中交第一航务工程局有限公司,天津300461

出　　处：《中国港湾建设》2021年第7期27-33,共7页China Harbour Engineering

基　　金：中交一航局科技研发项目(2016-9-3)。

摘　　要：基于宏电池腐蚀理论,将阴极钢筋和阳极钢筋分别浇筑在两个独立的混凝土试块中,用导线的连接或断开来模拟宏电池腐蚀或微电池腐蚀,通过往混凝土试块的预留孔中加水或将混凝土试块完全浸入水中来改变混凝土的水气环境,通过分析宏电池电位差、宏电池极化比率、宏电池电流密度和微电池电流密度,研究不同水气环境对混凝土中阴、阳极钢筋宏电池腐蚀行为的影响。结果表明:在阴极和阳极钢筋面积比为1的情况下,阴极钢筋和阳极钢筋周围混凝土的水气环境变化,对宏电池腐蚀电流、宏电池腐蚀极化比率及控制模式影响显著。当阴极或阳极钢筋周围的混凝土,由气中环境转为浸水环境后,宏电池腐蚀电流密度和微电池腐蚀电流密度的比率显著降低,且阴极钢筋周围混凝土的浸水状态要比阳极钢筋周围混凝土的浸水状态,更能有效地抑制宏电池腐蚀。当阴极钢筋和阳极钢筋周围的混凝土都完全浸入水中后,可最大限度地降低宏电池腐蚀速率,此时宏电池腐蚀的控制模式为典型的阴极控制。Based on the theory of macro-cell corrosion,cathodic steel and anodic steel were poured into two separated concrete blocks and were connected and disconnected by wires to simulate the macro-cell corrosion or micro-cell corrosion.The water-air environment of concrete was changed by filling water into the small holes distributed around the steel or completely immersing the concrete block in water.The influence of water-air environment change of concrete on the macro-cell corrosion behaviors of cathodic steel and anodic steel was investigated by analyzing the macro-cell potential difference,macro-cell polarization ratio,macro-cell current density and micro-cell current density.Results indicate that,under the condition that the area ratio of cathodic steel to anodic steel is 1:1,the change of water-air environments of concrete has a significant influence on the macro-cell current density,macro-cell polarization ratio and control mode.When the concrete around the cathodic steel or anodic steel changed from atmospheric environment to water-immersion environment,the ratio of macro-cell current density to micro-cell current density decreased remarkably,and the water-immersion environment of concrete around cathode is more effective than that of anode to inhibit the macro-cell corrosion.When the concrete around cathode steel and anode steel are completely immersed in water,the corrosion rate of the the macro-cell can be reduced to a maximum extent,and the control mode of macro-cell corrosion is the typical cathode control.

关 键 词：水气环境变化 钢筋混凝土 宏电池腐蚀 极化比率 控制模式 

分 类 号：U654[交通运输工程—港口、海岸及近海工程] U657[交通运输工程—船舶与海洋工程]