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为评估火灾后型钢混凝土柱的抗震能力,为其火灾后加固提供参考,进行了11个型钢混凝土柱试件的高温后抗震性能试验。试件在升降温过程中施加恒定轴向荷载,并且在高温后抗震试验中保持相同的轴向荷载水平。试验中考虑轴压比和受火时间对抗震性能的影响,以获取并分析试件的破坏特征、荷载-位移滞回曲线、刚度、延性和耗能能力。试验结果表明:型钢混凝土柱试件在反复荷载作用下由柱底混凝土剥落形成塑性铰,塑性铰长度为0.14H~0.44H(H为柱截面高度);试件在反复荷载作用下出现贯通全柱的黏结滑移裂缝,滞回曲线大致呈梭形,耗能能力较好;较之未受火试件,受火后试件滞回曲线更为饱满,骨架曲线更为平缓,位移延性系数略有增大,刚度和承载力退化明显,耗能能力略有降低。受火时间相同时,轴压比大的试件极限荷载略高,极限位移较小,延性差,耗能能力更强;轴压比相同时,受火时间越长,承载力和刚度下降越明显,延性略有提高,耗能能力变差。
In order to evaluate the seismic capacity of post-fire steel reinforced concrete columns and to provide references for post-fire reinforcement, 11 post-high-temperature seismic tests of SRC columns were carried out. The specimens were subjected to a constant axial load during ramp-up and maintain the same axial load level during high-temperature post-earthquake tests. The influence of axial compression ratio and fire time on the seismic performance was taken into account to obtain and analyze the failure characteristics, load-displacement hysteresis curve, stiffness, ductility and energy dissipation capacity. The experimental results show that the steel reinforced concrete column specimens are peeled off from the column bottom concrete to form plastic hinges under the repeated load. The length of the plastic hinges is 0.14H ~ 0.44H (H is the column section height) Compared with the unheated specimens, the hysteresis curve of the specimens is more full, the skeleton curve is more gentle, and the displacement ductility coefficient Slightly increased, the stiffness and bearing capacity degenerate significantly, energy consumption decreased slightly. When the fire time is the same, the ultimate load of the specimen with a large axial compression ratio is slightly higher, the limit displacement is smaller, the ductility is poor, and the energy dissipation capability is stronger. When the axial compression ratio is the same, the longer the exposure time and the lower the bearing capacity and rigidity Obviously, ductility slightly increased, power consumption worse.