Cl^-浓度渐变的混凝土孔隙液中钢筋的腐蚀过程

Corrosion Behavior of Reinforced Steel in Simulated Pore Solution with Gradual Augment of Cl^-

采用EIS和线性极化曲线技术研究了供货状态和打磨后的钢筋样品在模拟孔隙液中Cl-浓度渐变条件下的腐蚀行为。采用SEM结合EDS和XRD对钢筋表面形貌和组成结构进行了分析。结果表明:在Cl-浓度逐渐增加的孔隙液中,钢筋表面的电化学行为基本可分为3个过程,即钝化膜形成或修复过程、Cl-侵蚀过程和Ca沉积过程。供货状态钢筋比打磨后的钢筋样品更容易发生腐蚀。结合电极的腐蚀电位、腐蚀电流和电化学阻抗等参数随Cl-浓度的变化,讨论了混凝土中钢筋腐蚀发生、发展各阶段的腐蚀电化学过程的变化规律。

The corrosion behavior of reinforced steel with different surface states in simulated pore solution with gradual augment of C1- was investigated by using electrochemical measurements, scanning electron microscopy with energy dispersive SEM/EDS and XRD. The variation of corro- sion potential and corrosion current density of the reinforced steel with corrosion time was ob- tained, and the morphology and structure of corrosion products formed on the sample were ana- lyzed. The results showed that the reinforced steel with different surfaces state had different corro- sion characterizations; the corrosion process of reinforced steel might include three steps, i.e., the formation of passive film, the aggression of C1- and the calcium deposition. It is more easy to hap- pen corrosion for reinforced steel with oxide layer.