改性纤维编织网增强混凝土加固钢筋混凝土柱抗震性能

Seismic Behavior of Reinforced Concrete Columns Strengthened with Textile Reinforced Concrete Added Polyvinyl Alcohol Fiber

为研究掺入聚乙烯醇(PVA)纤维的纤维编织网增强混凝土(TRC)对加固钢筋混凝土(RC)柱抗震性能的影响,共制作了7根钢筋混凝土柱.其中,1根为对比柱,4根方形柱,1根圆柱,1根矩形柱.除对比柱外,其余6根钢筋混凝土柱均采用TRC加固.通过对7根试件进行低周往复加载试验,分析了不同PVA纤维掺量和截面形式下各试件的抗震性能指标.结果表明:TRC能够有效约束RC柱核心混凝土,掺入一定体积掺量的PVA纤维后,TRC的限裂效果进一步增强,提高了加固柱的开裂荷载和峰值荷载;PVA纤维体积掺量在0.5%以内时,加固柱的延性得到改善,刚度退化速率减慢,耗能能力增强,但随着体积掺量继续增大,延性和耗能能力均有所降低,刚度退化速率增大;TRC加固圆柱的承载能力较低,但延性、刚度退化以及耗能能力均优于其他两种截面形式的TRC加固柱.PVA纤维体积掺量在0.5%以内较为合理,且TRC加固后圆柱的抗震性能更好.

To investigate the seismic behavior of RC columns strengthened with textile reinforced concrete (TRC) added PVA fiber, seven reinforced concrete (RC) columns were designed, one of which was used as the control column,(Four of the columns were square, one was circular, and the rest were rectangular.) and six of which were strengthened with TRC. The low-frequency cyclic loading test was conducted by considering the volume quantities of PVA fiber and section forms of columns. The experimental results show that TRC can constraint the core area of concrete, restrict the development of concrete cracks effectively by adding a moderate PVA fiber, and the cracking loads and peak loads of the columns increase. When the volume quantities are within 0.5%, the ductility of the strengthened columns is improved, the stiffness degradation rate is small, and the energy dissipation increases. With the increase in volume quantities, the strengthened columns perform poorly in ductility, energy dissipation, and stiffness degradation. The circular column strengthened with TRC has a low bearing capacity, but it is superior to other cross section columns in ductility, stiffness degradation, and energy dissipation. The reasonable volume of PVA fiber should be less than 0.5%, and the strengthened circular column performs better in seismic behavior.