基于双向电迁移的开裂混凝土除氯阻锈效果

采用双向电迁移（BIEM）方法对沿海环境下的开裂混凝土进行修复，以排除裂缝附近富集的氯离子，并对钢筋进行阻锈防护. 通过测定阻锈剂浓度、氯离子质量分数以及钢筋极化曲线，研究不同裂缝宽度下BIEM的作用效应，并通过氯离子迁移特征试验对氯离子的迁移规律加以验证. 试验结果表明：开裂混凝土双向电迁移后，钢筋腐蚀电位均能恢复至较高水平；当裂缝宽度较小时，混凝土保护层中氯离子的迁移规律与未裂混凝土相近；当裂缝宽度大于0.3 mm时，裂缝处的氯离子排出效率随裂缝宽度的增加有所提高，但离裂缝较远处的氯离子排出效率有所降低.

Effect of chloride removal and corrosion prevention for cracked concrete based on bi-directional electro-migration rehabilitation

The bi-directional electro-migration (BIEM) method was used to repair the cracked concrete in the marine environment, in order to eliminate the chloride enriched in the vicinity of the crack and to prevent corrosion of the steel bars. The effect of BIEM under different crack widths was studied by measuring the concentration of rust inhibitor, mass fraction of chloride ion and the polarization curve of reinforcement. The chloride migration law was verified by the chloride migration characteristic test. Results that the corrosion potential of the steel can be restored to a high level after BIEM of the cracked concrete. When the crack width is small, the migration law of chloride ion in concrete cover is similar to that of the uncracked concrete. When the cracked width in concrete is greater than 0.3 mm, the chloride ion discharge efficiency at the crack increases with the increase of the crack width, while the discharge efficiency of chloride ion farther from the crack decreases.