- 摘 要
-
(西安公路研究院, 西安 710065)
[摘要]预应力CFRP板加固混凝土梁技术对其锚固件研究较多,而对其加固效果和破坏荷载下的力学模式缺乏数据分析。通过对空心板原型梁按比例缩小后制作3根混凝土实心模型梁,在预压和预应力CFRP板加固后考察不同荷载下梁的力学性能、破坏形态及裂缝发展。结果表明,该加固方法能有效地限制裂缝发展,提高混凝土梁承载力;加固件在较小荷载下符合平截面假定,预应力CFRP板和混凝土梁协同工作,随荷载增加,应变先减小后增大;施加的预应力使梁体应力重新分布,钢筋应力和构件变形都减小;理论计算与模型试验比较表明加固后梁体存在较大的安全储备。
[关键词]预应力; 碳纤维板; 加固; 混凝土; 力学性能
中图分类号:TU375, U445-7+2文献标识码:A文章编号:1002-848X(2017)21-0084-06
Study on mechanical failure modes of concrete beams reinforced by pre-stressed CFRP plate
Wang Xiaopeng, Feng Mingming, Zhang Guoqiang, An Lang, Yang Junchao
(Xi′an Highway Research Institute, Xi′an 710065, China)
Abstract:There is more research on its anchor in the technology of strengthening concrete beam with pre-stressed CFRP plate, but lack of data analysis on reinforcement effect and mechanical model under failure load. After scaling down the hollow slab prototype beam, 3 concrete solid model beams were fabricated. The mechanical properties, failure modes and crack development under different loads were investigated after strengthening pre-compressed and pre-stressed CFRP plates. The results show that the reinforcement method can effectively limit the development of cracks and improve the bearing capacity of concrete beam; Reinforcement components under small load were in line with the plane section assumption, and the CFRP plate and concrete beam achieve deformation coordination, in which the strain decreases first and then increases with the increase of load; Applied pre-stress makes girder stress redistributed, and reinforcement stress and the deformation of the components were reduced; Comparison of theoretical calculation and model test show that after reinforcement beam has a large safety reserve.
Keywords:pre-stress; carbon fiber plate; reinforcement; concrete; mechanical property
*陕西省交通运输厅科技项目“预应力CFRP板加固技术在混凝土桥梁中的推广应用研究”(项目编号13-33T)。
作者简介:汪小鹏,硕士,高级工程师,Email: wxp2015369@126.com。