钢-ECC组合梁负弯矩区受弯性能试验研究

发布时间：2019-01-16 06:19

【摘要】：纤维增强水泥基复合材料(Engineered Cementitious Composite,ECC)具有高延展性以及受拉刚化特点,应用于组合梁桥的负弯矩区时可有效减少桥面板的受拉开裂。完成了2根钢-ECC组合梁和1根钢-混凝土组合梁对比构件在负弯矩作用下的静力加载试验,通过试验研究了不同配筋率的ECC对结构受力性能特别是抗裂性的影响。试验研究表明:在负弯矩作用下,钢-ECC组合梁的刚度较钢-混凝土组合梁明显提高;由于ECC翼板的抗拉作用导致截面中和轴上升,钢梁受压区增大,构件延性有所降低;钢-ECC组合梁可有效提高结构的开裂荷载并减小裂缝宽度,提高配筋率有利于进一步减少ECC翼板的裂缝宽度。提出了钢-ECC组合梁的承载力与开裂荷载的计算方法,提供了挠度分析的方法和裂缝宽度的基本模型。
[Abstract]:Fiber reinforced cement matrix composite (Engineered Cementitious Composite,ECC) has the characteristics of high ductility and tensile stiffening. When used in the negative moment region of composite beam bridge, the tensile cracking of bridge deck can be effectively reduced. The static loading tests of two steel-ECC composite beams and one steel-concrete composite beam under negative bending moment were carried out. The effects of ECC with different reinforcement ratios on the mechanical properties of the structure, especially the crack resistance, were studied. The experimental results show that the stiffness of steel-concrete composite beams is significantly higher than that of steel-concrete composite beams under negative bending moment, and the ductility of steel beams increases due to the tensile resistance of ECC flange, which leads to the increase of section and axis, the increase of compression zone of steel beams, and the decrease of ductility of members. Steel-ECC composite beam can effectively increase the crack load and reduce the crack width of the structure, and the increase of reinforcement ratio can further reduce the crack width of the ECC flange. The calculation method of bearing capacity and cracking load of steel-ECC composite beam is put forward. The method of deflection analysis and the basic model of crack width are provided.
【作者单位】：清华大学土木工程安全与耐久教育部重点实验室;
【基金】：国家自然科学基金(51222810) 清华大学自主科研项目(20161080103)
【分类号】：TU398.9

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