（1 宜春学院土木工程系， 宜春 336000；  2 南京航空航天大学土木与机场工程系， 南京 210016）

［摘要］采用电化学方法对纵筋进行锈蚀，通过加载试验研究了再生混凝土梁在不同纵筋锈蚀率下刚度退化规律。结果表明：再生混凝土梁破坏时的极限承载力随锈蚀率的增加而减小，当锈蚀率较小时，大约在5%极限承载力的荷载时梁在纯弯段内开始出现裂缝，破坏形态为适筋梁弯曲破坏；当锈蚀率较大时，破坏时裂缝分布有向跨中靠拢的趋势。当荷载较小时，随着纵筋锈蚀率的增加再生混凝土梁跨中挠度变化不大；当荷载较大时，跨中挠度随纵筋锈蚀率增大而增大变得比较明显。再生混凝土梁的刚度因纵筋锈蚀发生了一定的退化，导致刚度退化的主要原因是再生混凝土梁截面和纵筋横截面面积减小以及二者之间粘结性能的退化，并基于钢筋截面面积减小这一因素推导了再生混凝土梁弯曲刚度退化计算方法。

［关键词］再生混凝土；钢筋锈蚀；锈蚀率；刚度退化；弯曲刚度

中图分类号：TU375.1文献标识码：A文章编号：1002-848X(2021)04-0086-05

Degradation law and calculation method of  stiffness of  recycled concrete beams with corroded rebars

ZOU Zhenghao1,2, YANG Guojiao1, WU Jin2, SU Tian2

(1 Department of Civil Engineering, Yichun University, Yichun 336000, China;2 Department of Civil and Airport Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China)

Abstract:The electrochemical method was used to corrode the longitudinal rebars, and the stiffness degradation law of recycled  concrete beams under different corrosion rate of longitudinal rebars was studied by loading tests. The results show that the ultimate bearing capacity of recycled concrete beams decreases with the increase of corrosion rate. When the corrosion rate is small, cracks begin to appear in the pure bending section at the load about 5% of the ultimate bearing capacity, and the failure mode is flexural failure of balanced-reinforced beam. When the corrosion rate is large, the distribution of cracks tends to be closer to the mid-span. When the load is small, with the increase of the corrosion rate of longitudinal rebars, the mid-span deflection of the recycled concrete beam does not change much, when the load is large, the mid-span deflection increases obviously with the increase of the corrosion rate of longitudinal rebars, and the  stiffness of the recycled concrete beam is degenerated due to the corrosion of longitudinal rebars, the main reasons for the stiffness degradation are the reduction of the cross-sectional area of recycled concrete beams and longitudinal bars, and the degradation of the bond performance between them, thus the calculation method of the degradation of the flexural stiffness of the recycled concrete beam was derived based on the reduction of the cross-sectional area of the rebars.

Keywords:recycled concrete;rebar corrosion;corrosion level;stiffness degradation;flexural stiffness

*江苏省研究生科研创新计划项目（KYCX17_0272）。

作者简介：邹正浩，博士，讲师，Email: zouzhenghao@nuaa.edu.cn；通信作者：吴瑾，博士，教授，Email:wujin@nuaa.edu.cn。