电化学修复后钢筋疲劳性能试验研究

为了探明电化学修复对钢筋疲劳性能的影响，开展电化学除氯和双向电迁处理后钢筋的轴向拉伸疲劳试验. 基于断裂力学原理及断口微观形貌分析，揭示电化学修复技术引起钢筋疲劳性能变化的机理. 结果表明，电化学除氯会引起钢筋疲劳裂纹门槛值的减小及疲劳弹性模量的退化，宏观表现为钢筋疲劳寿命减小；电化学除氯后钢筋疲劳裂纹起源于钢中白点，裂纹扩展区疲劳辉纹间距增大，瞬断区韧窝变小变浅. 掺入阻锈剂的双向电迁方法对钢筋疲劳性能的负面影响较小，双向电迁修复后钢筋的疲劳断口微观形貌相对于普通钢筋未见明显变化.

Experimental study on fatigue properties of steel bars after electrochemical repair

The axial tensile fatigue test of steel bars after electrochemical chloride extraction and bidirectional electromigration rehabilitation was conducted in order to analyze the influence of electrochemical repair on the fatigue properties of steel bars. The mechanism of fatigue properties changes of steel bars caused by chemical repair techniques was explained based on the fracture mechanics principle and the fracture micromorphology. Results show that electrochemical chloride extraction causes the fatigue crack threshold of the steel bar to decrease and the fatigue elastic modulus to degrade. The macroscopic phenomenon is the reduction of fatigue life. The fatigue cracks of steel bars originated from the white point in the steel after electrochemical chloride removal, the fatigue striation spacing increases, and the dimples in the short-term fault zone become smaller and lighter. The bidirectional electromigration rehabilitation with the rust inhibitor has less negative impact on the fatigue performance of the steel bar. There are no obvious changes in the micromorphology of the steel bars after bidirectional electromigration.