配置600MPa级高强钢筋高韧性混凝土边节点受力性能试验研究

Experimental research on mechanical behavior of exterior joint with 600MPa high strength steel reinforcement and high toughness concrete

通过对配置600MPa级高强钢筋高韧性混凝土边节点进行低周往复荷载试验,分析边节点的破坏形态、剪力与转角等,对比边节点核心区混凝土应变和箍筋应变等受力性能指标,研究混凝土种类及剪压比的变化对边节点受力性能的影响。研究结果表明：减小配置600MPa级高强钢筋高韧性混凝土边节点的剪压比可以改善其破坏形态,降低其核心区剪切变形,但使节点的剪力降低。节点中浇筑高韧性混凝土可以显著改善配置600MPa级高强钢筋边节点核心区的混凝土脱落,从而改善其破坏形态,减小加载初期核心区的箍筋应变,提高边节点核心区混凝土的主拉应变,降低边节点核心区剪切变形;边节点的平行受力方向的箍肢应变明显大于垂直受力方向的箍肢应变。

The low-cyclic loading test was conducted on exterior joints with 600 MPa high strength steel reinforcement and high toughness concrete to analyze the failure modes,shear forces,and rotation angles of the exterior joints. The stress performance indexes such as concrete strain and stirrup strain in the core region of the node were analyzed,to investigate the influence of the variation of concrete type and shear compression ratio on the mechanical behavior of exterior joints. The results show that reducing the shear compression ratio of exterior joints with 600 MPa high strength steel reinforcement and high toughness concrete can improve its failure mode and reduce its shear deformation in the core region,but it can reduce the shear force at the nodes. The pouring of high toughness concrete in the nodes significantly improves the concrete shedding in the core region of the exterior joints with 600 MPa high strength steel reinforcement and high toughness concrete,thereby improving the failure mode,reducing the strain of the stirrups in the core region during the initial loading,improving the main tensile strain of the concrete in the core region of the nodes,and reducing shear deformation of core region of exterior joints. The strain of the stirrup limb under the parallel force direction of the exterior joint specimen is obviously larger than that of the stirrup limb under the vertical force direction.