用交流阻抗谱研究活性砂浆胶结材料的电化学行为

Electrochemical Performance of Active Mortar Cementitious Materials via AC Impedance Spectroscopy

海水环境潮差浪溅区钢筋混凝土结构易腐蚀破损,可采用锌网阳极与活性砂浆组成的牺牲阳极阴极保护系统进行修复保护。用交流阻抗谱方法对活性砂浆胶结材料的电化学性能进行了研究,并采用等效电路对阻抗谱进行拟合解析。结果表明:砂浆中掺入活性组分后,砂浆电阻显著降低,极化电阻与扩散阻抗系数也随活性组分的掺入大幅度降低;活性砂浆中阳极表面膜层不再是致密钝化的状态,表面易于进行阴极反应;活性组分同等掺量条件下,溴化锂更利于提高砂浆的电化学活性。

In tidal and splash zone of seawater environment, the structures of reinforced concrete are easily and seriously damaged due to the corrosion, which can be repaired and protected by sacrifical anode cathodic protection system composed of zinc mesh and active mortar. The electrochemical performance of active mortar cementitious materials was determined by AC impedance spectroscopy, and the impedance spectra were analyzed via the equivalent circuit. The results show that the resistance of mortar mixed with some active components decreases. The polarization resistance and coefficient of diffusion impedance of mortar mixed with active components also decreased, and the surface of anode in active mortar was not in compact passivation state. The cathodic reaction occurred easily on the surface of the anode. LiBr is better for be used to improving the electrochemical activity of mortar at the same quantity level.