预应力RPC-NC叠合梁抗弯延性试验分析

发布时间：2019-05-23 10:29

【摘要】：为有效推动高性能材料在现代桥梁结构中的应用以满足快速发展的高速铁路技术,本文设计并制作了10根预应力活性粉末混凝土(RPC)-普通混凝土(NC)叠合梁和1根预应力纯NC梁,通过试验方法研究了高性能材料RPC在梁结构中应用后叠合梁的抗弯延性性能,并以叠合梁跨中位移延性系数进行描述.试验主要考虑了RPC高度、预应力比率、NC等级等因素对叠合梁抗弯延性的影响.研究结果表明:随着RPC高度的增加,叠合梁截面配筋指数降低,抗弯位移延性系数增大;随着钢绞线根数的增多,预应力比率增大,位移延性系数相应增大;叠合梁上部NC等级提高后,脆性破坏特征并不明显,抗弯位移延性系数增大.由于RPC材料优异的力学性能以及钢纤维的作用提高了叠合梁在出现峰值荷载后的变形能力,使得其抗弯位移延性要明显优于纯NC梁,可见RPC材料在拥有高强度的同时具有良好的延性特征.同时以试验数据为基础,拟合出适用于预应力RPC-NC叠合梁抗弯位移延性系数的计算公式.
[Abstract]:In order to effectively promote the application of high performance materials in modern bridge structures to meet the rapid development of high speed railway technology, In this paper, 10 prestressed reactive powder concrete (RPC)-ordinary concrete (NC) composite beams and 1 prestressed pure NC beam are designed and fabricated. The bending toughness of superimposed beams with high performance material RPC applied in beam structures is studied by means of test, and the ductility coefficient of displacement in span of superimposed beams is described. The effects of RPC height, prestress ratio and NC grade on the bending toughness of composite beams are mainly considered in the test. The results show that with the increase of RPC height, the reinforcement index of composite beam section decreases and the coefficient of bending displacement toughness increases, and with the increase of the number of steel strand roots, the prestress ratio increases and the displacement ductility coefficient increases accordingly. With the increase of NC grade in the upper part of the superimposed beam, the brittle failure characteristics are not obvious, and the coefficient of bending displacement toughness increases. Because of the excellent mechanical properties of RPC material and the action of steel fiber, the deformation ability of composite beam after peak load is improved, so the bending displacement toughness of composite beam is obviously better than that of pure NC beam. It can be seen that RPC materials not only have high strength, but also have good ductile characteristics. At the same time, based on the test data, the formula suitable for calculating the bending displacement toughness coefficient of prestressed RPC-NC composite beams is fitted.
【作者单位】：交通基础设施安全风险管理交通运输部重点实验室(北京交通大学);
【基金】：国家自然科学基金(51278040) 教育部中央高校基本科研业务费(2014YJS106)
【分类号】：U446

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