GFRP套管钢筋混凝土短柱轴压力学性能试验研究

Experimental study on mechanical properties of axially loaded GFRP tubed short reinforced concrete columns

为研究GFRP套管钢筋混凝土短柱的轴压力学性能,进行了22个GFRP套管钢筋混凝土短柱和6个无GFRP套管约束的钢筋混凝土短柱对比试验。研究了影响GFRP套管钢筋混凝土组合短柱轴压力学性能的主要因素,包括GFRP套管不同的受力方式、混凝土强度、纵筋配筋率等。试验结果表明:由于GFRP套管的约束,提高了核心混凝土的强度,增大了核心混凝土的变形能力;GFRP套管在不同的受力方式下,组合短柱的轴压承载力和变形基本相同;GFRP套管内配置纵筋可提高GFRP套管混凝土短柱的轴压承载力,适当提高纵筋配筋率可改善短柱的延性。根据试验结果及现有FRP管约束混凝土轴心抗压强度计算公式,建议了GFRP套管钢筋混凝土短柱承载力计算公式,计算结果与试验结果基本吻合。

Twenty-two GFRP tubed short reinforced concrete columns and six columns without GFRP tube confined were tested under axial load to investigate mechanical properties of axially loaded GFRP tubed short reinforced concrete columns. The principal influencing factors such as loading condition, concrete strength and ratio of longitudinal reinforcement were studied. Test results indicate that strength and deformation performance of core concrete are increased as a result of the confinement of GFRP tube. Load-carrying capacity and deformation of short composite columns with different loading condition are much the same. Load-carrying capacity and ductility of GFRP tubed short columns are improved because of the longitudinal reinforcement in GFRP tube. According to the experimental results together with the existing strength equation of FRP tube confined concrete, the calculation formula ultimate load-carrying capacity for the short composite columns are proposed. The results calculated by the proposed model compare well with the experimental results.