(1 南京工程学院经济与管理学院， 南京 211167； 2 南京航空航天大学金城学院， 南京 211156）

［摘要］为探讨ECC在结构新建、加固等领域的应用，开展钢筋增强混凝土-ECC组合梁的抗弯性能全过程理论研究，分析组合梁在弹性阶段、带裂缝工作阶段、破坏阶段的破坏现象，结合平截面假定和本构关系分析各阶段截面的应力-应变关系，依据力和力矩平衡原则建立抗弯承载力计算公式，通过组合梁和RC梁的抗弯试验验证理论的正确性，进一步理论分析不同ECC厚度对组合梁的抗弯承载力和延性性能的影响。研究表明：与RC梁相比，用ECC替代部分受拉区混凝土承载力可提高60%以上，位移延性可提高46%以上；ECC厚度在19%～38%梁高范围内可获得较为优越的抗弯承载力和延性；为发挥ECC材料的高延性应将其与高强混凝土和高强钢筋结合使用，并着眼于提高构件的阻裂、限裂、增韧等性能。

［关键词］全过程抗弯性能； 抗弯承载能力； 延性； ECC厚度

中图分类号：TU375-2文献标识码：A文章编号：1002-848X(2019)14-0056-06

Theoretical and experimental study on flexural behavior of steel reinforced concrete-ECC composite beams

Hu Shixiang1, Luo Min2, Li Yale2, Chen Peng2, Xu Bailin2

（1 School of Economics ＆ Management, Nanjing Institute of Technology, Nanjing 211167, China；2 Jincheng College, Nanjin University of Aeronautics and Astronautics, Nanjing 211156, China）

Abstract:In order to discuss the application of ECC in the field of new construction and reinforcement of structures, the whole process theoretical study of flexural behavior of steel reinforced concrete-ECC composite beams was carried out. The failure phenomena of composite beams in the elastic stage, the working stage with cracks and the failure stage were analyzed. The stress-strain relationship of sections in each stage was analyzed based on the assumption of plane section and the constitutive relationship, and the flexural resistance was established according to the principle of force and moment balance. The correctness of the theory was verified by the flexural tests of composite beams and RC beams, and the effect of different ECC thickness on the flexural capacity and ductility of composite beams was further analyzed theoretically. The results show that, compared with RC beams, the bearing capacity  of beams with ECC in partial tension zone can be increased by more than 60% and the displacement ductility can be increased by more than 46%. When the ECC thickness ranges from 19% to 38% of beam height, the beams can obtain better flexural bearing capacity and ductility. In order to give full play to the high ductility of ECC materials, ECC should be combined with high strength concrete and high strength steel bars, and focus on improving the crack resistance, crack limitation and ductility behaviors of members.

Keywords:whole process flexural behavior; flexural capacity; ductility; ECC thickness

*南京工程学院校级科研基金（YKJ201724），江苏省高校自然科学研究面上项目（17KJB560006）。

作者简介：胡世翔，博士，讲师，Email:hqhsx@163.com。