锈蚀箍筋约束混凝土柱低周往复试验研究

The low reversed cyclic loading tests of concrete column confined by corroded stirrups

为了解锈蚀箍筋约束混凝土柱的抗震性能,通过加速锈蚀试验得到8根锈蚀混凝土柱,并对其进行低周反复荷载试验,研究箍筋锈蚀后混凝土柱的受力特点和破坏机制,对比分析箍筋直径、箍筋间距等参数变化对锈蚀箍筋约束混凝土柱的承载能力、延性、滞回特性、刚度退化、强度退化和耗能等抗震性能指标的影响.结果表明:箍筋锈蚀后,混凝土受到的约束作用降低,导致混凝土柱抗震性能退化;随着箍筋锈蚀量增大,柱破坏时的极限位移减小,滞回曲线出现捏拢现象且逐渐明显,强度降低程度和刚度衰减程度均增大,延性和耗能能力降低,相同控制位移下的累计耗能量增大.

To understand the seismic behaviors of concrete column confined by the corroded stirrups,the low reversed cyclic loading tests have been carried out for eight pillars of corroded reinforced concrete columns,The mechanical characteristics and failure mechanism of concrete column confined by the corroded stirrups,and the influence on the seismatc performance indicators such as bearing capacity,ductility,hysteretic characteristics,stiffness degradation and the strength degradation and energy dissipation were also analyzed comparatively by the parameters such as stirrup diameter,stirrup spacing changes.The experimental results showed that the restraint of concrete provided by corroded stirrups is reduced,which leads to aseismatic performance degradation of concrete column.As the stirrups′corrosion quantity increases,the failure limit displacement of column decreases,and the pinch phenomenon of hysteresis curve is gradually obvious,and the attenuation degree of strength and stiffness is increased.The ductility and energy dissipation capacity is reduced,and the accumulated energy is increased under the same control displacement meanwhile.