混凝土中钢筋阳极极化性能与其腐蚀状态的关系研究

Study on the Relationship Between Anodic Polarization and Corrosion State of Reinforcement in Concrete

对混凝土内钢筋的阳极极化性能与其腐蚀状态的关系进行了研究。结果表明,钢筋阳极极化曲线中的维钝区间与钢筋表面的钝化状态有很好的相关性。当维钝区间大于280mV时,钢筋表面钝化状态保持良好;当维钝区间下降至250～280mV后,钢筋表面开始脱钝并出现部分锈蚀,即阳极极化曲线中250～280mV维钝区间为钢筋表面脱钝并开始锈蚀的节点。混凝土中钢筋表面的脱钝时间与其中氯离子含量具有较为密切的关系,试验中脱钝时间t与氯离子含量c的函数关系为t=-39.8ln(c)+84.4。

The relationship between anodic polarization and corrosion state of reinforcement in concrete was studied. The results show that passivation state of reinforcement was intimately related to size of passive potential interval. When the size of passive potential interval is greater than 280 mV, the reinforcement presents excellent passivation property; while the size of passive potential interval reduces to about 250;280 mV, the reinforcement Could not passive and start to corrosion. So 250-280 mV in：the size of passive potential interval could seem to be critical point of depassivation of rein- forcement. And chloride ion has significant influence on the depassivation time of reinforcement, depassivation time of reinforcement （t） and content of chloride ion （c） have function relationship as t=--39.81n（c）＋84. 4 in this study.