新型钢筋网约束矩形节点的局部受压性能研究

为研究新型钢筋网约束矩形节点在低强度混凝土中的局部受压性能,对11个试件进行了轴压试验,讨论试件几何参数与体积配筋率对承载力的影响.试验结果表明,在节点钢筋网外围配置箍筋,可以有效改善节点区的抗裂性能;试件相对高度与其极限承载力成反比,但相对高度大的试件具有较大的初裂荷载;钢筋网体积配筋率对极限承载力有一定的提高作用,但对抗裂性能没有明显改善.借鉴约束混凝土本构模型,建立了力学概念清晰的核心混凝土等效应力-应变关系.采用建议的等效应力-应变关系对相关试验试件进行了全过程分析,计算曲线和试验曲线吻合良好.

Study of the Compression Behavior of Rectangular Concrete Joint with the Confinement of Mesh Reinforcement

In order to study the compression behavior of rectangular concrete joint with new type of mesh reinforcement, local compression experiments of 11 square specimens were carried out. The influence of the specimen's geometric parameters and the volumetric ratio of reinforcement on the bearing capacity was studied. With the confinement of stirrups around mesh reinforcement, the crack resistance of specimens was effectively improved. The height factor was the main influencing factor of the bearing capacity, the bearing capacity increased with the decrease of height, but specimens of higher relative height showed higher anti-cracking performance. The volumetric ratio of mesh reinforcement has some effect on the bearing capacity, but its influence was not obvious on the crack resistance. The constitutive relationship of confined concrete was adopted to build the equivalent stress-strain relationship for the core concrete of the specimens. The results of equivalent stress-strain curves calculated by the proposed constitutive relationship are in good agreement with the experiments.