型钢再生混凝土柱-钢梁组合框架节点抗剪承载力研究

SHEAR BEARING CAPACITY OF STEEL REINFORCED RECYCLED CONCRETE COLUMN-STEEL BEAM COMPOSITE FRAME JOINTS

  • 摘要: 为研究型钢再生混凝土柱-钢梁(SRRC柱-S梁)组合框架节点的抗剪承载力,该文对8个组合框架节点试件进行低周反复荷载试验,观察试件破坏过程及破坏形态,获得各加载阶段试件中型钢和钢筋的应变,分析再生粗骨料取代率和轴压比对节点抗剪承载力的影响规律。结果表明:节点抗剪承载力随取代率的增大而降低,但降低幅度不大;适当增大轴压比可以提高节点的抗剪承载力;试件屈服前,节点剪力主要由核心区再生混凝土承担;屈服后型钢腹板和箍筋起主要抗剪作用。在此基础上,分析节点区受力机理,推导型钢腹板、箍筋和再生混凝土各部分抗剪计算方法,最后通过叠加法建立该节点的抗剪承载力公式,计算结果与试验结果吻合较好,研究结果可为型钢再生混凝土柱-钢梁组合框架节点的工程应用提供参考。

     

    Abstract: In order to study the shear bearing capacity of SRRC column-Steel beam composite frame joints, eight joint specimens were subjected to low cyclic loading tests. The failure process and failure modes of the specimens were observed and the strain of steel and rebars at each loading stage were obtained. The influences of the axial compression ratio and recycled coarse aggregate replacement percentage on the shear bearing capacity of joints were analyzed in detail. The results show that the shear bearing capacity of the joints decreases with the increase of replacement percentage, but the reduced magnitude of shear bearing capacity is relatively small. Appropriate increase of the axial compression ratio can improve the shear bearing capacity of the joints. Before the specimens became yielded, the shearing bearing force was mainly undertaken by the recycled concrete in the core of joints. After being yielded, the shearing bearing force was mainly undertaken by the steel webs and stirrups. Based on the test findings, the failure mechanism of composite frame joints was analyzed, and the expressions of shearing force of steel webs, stirrups and recycled concrete were proposed. Finally, the formula of shear bearing capacity for SRRC columns-Steel beams composite frame joints was established by in term of the superposition method. The calculated results agree well with the test results. The work could be used as a reference for the construction practice of the SRRC columns-Steel beams composite frame joints.

     

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