薄壁U形外包钢再生混合梁受弯性能试验研究

发布时间：2018-04-08 17:27

本文选题：钢-混凝土混合梁　切入点：薄壁U形外包钢　出处：《建筑结构学报》2014年04期

【摘要】：对8个含有废弃混凝土块体的薄壁U形外包钢再生混合梁及4个全现浇组合梁进行受弯试验,研究废弃混凝土块体取代率、U形外包钢壁厚、梁底纵筋配筋率等参数对试件受弯性能的影响,给出试件受弯承载力的简便计算式,在总用钢量基本一致的情况下对比薄壁U形外包钢再生混合梁和常规钢筋混凝土梁的受弯承载能力。结果表明:废弃混凝土块体取代率在0~40%之间变化对薄壁U形外包钢再生混合梁的初始刚度、延性、受弯承载力、U形外包钢与内部混凝土之间的相对滑移、应变发展特征无明显影响;为提高薄壁U形外包钢再生混合梁的受弯承载力,增配梁底纵筋比增加外包钢壁厚更为经济有效,同时梁底纵筋还使试件的屈服前刚度有所提高;梁底配置纵向钢筋可显著减小U形外包钢与混凝土之间的相对滑移,此时梁端截面为相对滑移最小截面;根据塑性理论给出的计算式可较好地预测薄壁U形外包钢再生混合梁的受弯承载力,在总用钢量基本相同的情况下该类构件具有与常规钢筋混凝土梁几乎相当的受弯承载力。
[Abstract]:Eight thin-walled U-shaped steel recycled composite beams with abandoned concrete blocks and four cast-in-situ composite beams were subjected to bending tests, and the wall thickness of U-shaped steel encased by the replacement rate of abandoned concrete blocks was studied.The influence of beam bottom longitudinal reinforcement ratio and other parameters on the flexural behavior of the specimen is studied. A simple formula for calculating the flexural capacity of the specimen is given.The flexural bearing capacity of thin-walled U-shaped steel reclaimed composite beams and conventional reinforced concrete beams is compared under the condition that the total steel content is basically the same.The results show that the initial stiffness, ductility, flexural bearing capacity and relative slip between U-shaped steel and internal concrete are affected by the change of replacement ratio of abandoned concrete blocks in the range of 0 ~ 40% for thin-walled U-shaped steel reclaimed composite beams.In order to increase the flexural capacity of thin-walled U-shaped steel reclaimed hybrid beams, it is more economical and effective to increase the longitudinal reinforcement at the bottom of the beam than to increase the wall thickness of the steel. At the same time, the longitudinal reinforcement at the bottom of the beam also increases the stiffness of the specimen before yield.The longitudinal reinforcement at the bottom of the beam can significantly reduce the relative slip between U-shaped steel and concrete, and the end section of the beam is the minimum section of relative slip.According to the plastic theory, the calculation formula can be used to predict the flexural bearing capacity of thin-walled U-shaped steel reclaimed composite beams. Under the condition of the same total steel consumption, the flexural bearing capacity of this kind of members is almost equal to that of conventional reinforced concrete beams.
【作者单位】：华南理工大学亚热带建筑科学国家重点实验室;
【基金】：国家杰出青年科学基金项目(51025829) 国家科技支撑计划子课题(2011BAJ09B03-04) 亚热带建筑科学国家重点实验室项目(2011ZB07,2013ZB24)
【分类号】：TU398.9;TU317

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