负载下碳纤维布约束混凝土方柱的轴压试验

Experimental Research on Axially Loaded Square-section Concrete Columns Confined by Carbon Fiber Reinforced Plastic(CFRP) Under Preload

碳纤维布约束混凝土柱可以提高其强度和延性,是一种经济、有效的常用加固方法。过去的研究工作大多集中在无负载的混凝土柱,而在实际加固工程中,混凝土柱通常处于负载状态。通过16个碳纤维布约束混凝土方柱的轴压试验,研究了方柱在不同的负载水平和碳纤维包裹层数下的破坏特征和力学性能,并对负载导致约束混凝土峰值点应力和应变下降的原因进行了分析。试验结果表明,负载水平的大小对于碳纤维布的约束效果是有明显影响的。随着负载水平的提高,第2阶段刚度、峰值点应力和应变均逐渐下降;而碳纤维布包裹层数的增加,则放大了这种效应。

16 square-section concrete columns confined by CFRP sheet were tested in uniaxial compression involved in different preload ratio and CFRP plies.The failure characteristic and mechanics behavior of confined concrete columns were presented,and the descending of the peak stress and strain of confined concrete due to preload were analyzed.The experimental results indicated that the confinement effect of CFRP was influenced by preload ratio observably.The second stiffness,the peak stress and strain declined with preload ratio ascending,and the extent developed with the enhancement of CFRP ply.