外包角钢加固钢筋混凝土柱轴心受压承载力计算方法研究

Bearing Capacity Calculation Method for Axially Compressed RC Columns Strengthened with Angle Steel

外包角钢加固混凝土柱轴心受压试验研究结果表明,外包角钢一方面直接参与承受轴向压力,另一方面与缀板形成钢骨架体系约束内部混凝土,从而提高了被加固柱的极限承载力和延性。在试验研究的基础上,分析了角钢和混凝土的受力状态。采用极值法和简化法两种计算角钢加固混凝土柱轴心受压承载力的计算方法,考虑到角钢体系对混凝土的约束作用,将核心混凝土划分为双轴受压区及三轴受压区,其计算结果与试验结果吻合较好。本文所提出的简化计算方法计算简便,可为工程应用提供参考。

The experimental test on the axially compressed RC columns strengthened with angle steels shows that the angle steel can work harmonically with the concrete, the angle steels bear the pressure directly, the frame formed by the angle steels and the batten plates can provide effective confinement to the core concrete, so the ultimate bearing capacity and ductility of the reinforced columns improve obviously. Based on the experimental test, the stress state of angle steels and concrete are discussed. Furthermore, limit method is proposed to calculate the bearing capacity of axially compressed RC columns strengthened with angle steel. Considering the confinement of angle steel to concrete, the concrete core is divided into biaxial compression zone and tri-axial compression zone. To simplify the calculation, a more convenient simplified method for engineering application is also proposed. Bearing capacities calculated by both of the two methods show the consistency with the test results.