不同电化学参数的双向电迁移作用下钢筋断口形貌特征

双向电迁移技术可显著提升钢筋混凝土结构耐久性,不同电化学参数会引起钢筋力学性能变化。文章通过恒应变速率拉伸方法对双向电迁移修复后混凝土内钢筋进行拉伸试验,采用电镜扫描(SEM)钢筋断面,对不同电流密度下电化学修复后的钢筋断口进行宏观与微观分析,观察其宏观断口形态,微观断口形貌特征。试验表明随着电流密度增大,相同倍率电镜中断口凹坑较深韧窝的数量逐渐减少,韧窝凹坑逐渐变小而浅。

Bidirectional electromigration rehabilitation can significantly improve the durability of reinforced concrete structure,and different electrochemical parameters can cause changes in the mechanical properties of steel bars.In this paper,through the constant strain rate tensile method,the tensile test was carried out on the reinforcement in the concrete afterbidirectional electromigration rehabilitation(BIEM).The cross-section of the reinforcement after the electrochemical repair under different current density was analyzed by scanning electron microscope(SEM),the macro fracture morphology and micro fracture morphology were observed.The results show that with the increase of current density,the increase of the number of deep dimples in the break hole of the same magnification electron microscope decreases gradually,and the dimples in the dimples become smaller and shallower.