混掺高延性纤维混凝土组合十字形短柱抗震性能研究

为改善钢筋混凝土十字形短柱的抗震性能，将高延性纤维混凝土用于十字形短柱底部。通过对混掺高延性纤维混凝土组合十字形短柱（R/ECC）和普通钢筋混凝土十字形对比柱（RC）进行拟静力试验，分析其裂缝开展模式、破坏形态、滞回性能、延性、耗能能力和刚度退化等，研究混掺高延性纤维混凝土对十字形短柱抗震性能的提升作用。结果表明，在十字形短柱底部采用混掺高延性纤维混凝土，可有效控制裂缝的开展，减小裂缝宽度，改善柱底混凝土的压溃剥落状态；短柱的延性和耗能能力明显提高，刚度退化缓慢，承载力有一定提高。相比RC柱，R/ECC柱位移延性系数、峰值点和极限点时累积滞回耗能分别提高7.3%、225.5%和44.6%，受剪承载力提高9.5%。

Seismic behavior of hybrid high ductility fiber reinforced concrete composite cross-shaped short columns

To improve the seismic behavior of the cross-shaped short column, the concrete was substituted with high ductility fiber reinforced concrete in the bottom of the cross-shaped short column. Quasi-static tests on the hybrid high ductility fiber reinforced concrete composite cross-shaped short column (R/ECC) and the reinforced concrete cross-shaped short column (RC) were carried out. The crack propagation mode, failure characteristics, hysteretic behavior, ductility, energy dissipation and stiffness degradation were compared to investigate the seismic behavior of the R/ECC column. The results show that the hybrid high ductility fiber reinforced concrete can effectively control the development of the crack, decrease the width of the crack and improve the state of collapse and spalling. The ductility and energy dissipation of the composite column are improved obviously. The stiffness degradation becomes lower, and the shear capacity is improved. Compared with RC column, the displacement ductility factor, as well as the cumulative hysteretic energy dissipation at the peak and limit points of R/ECC column increased by 7.3%, 225.5% and 44.6%, respectively, and the shear capacity increased by 9.5%.