预应力钢箍加固混凝土圆形短柱轴压性能研究

对33个预应力钢箍加固混凝土圆形短柱(PSHC)及9个对比柱进行轴压性能试验,研究配箍率(包括钢箍间距、混凝土柱直径)、预应力比、初始轴压比等因素对PSHC承载能力和变形能力的影响。结果表明:PSHC的承载能力和变形能力相比于对比柱,可分别提高107%和540%。加固效果会随着钢箍配箍率的增加而变好;预应力比逐渐增加时PSHC承载能力逐渐增加,峰值应变逐渐降低;初始轴压比的大小不会对加固效果产生明显影响,预应力钢箍加固混凝土柱技术可以作为一种不卸荷的加固方式。此外,提出PSHC承载力计算方法,用该文试验和其他学者试验数据进行验证,计算结果与试验结果吻合良好。

STUDY ON AXIAL COMPRESSION PERFORMANCE OF CONCRETE STUB COLUMN STRENGTHENED BY PRESTRESSED STEEL HOOP

Both thirty-three concrete stub columns reinforced by prestressed steel hoops (PSHC) and nine unreinforced columns were tested under axial compression. The studied parameters were the hoop ratio (the spacing of hoops and the concrete diameter), the prestressing level and the initial axial compression ratio. The influences of these parameters on the carrying capacity and deformation capacity of PSHC were obtained and discussed. The results show that the bearing capacity and deformation capacity of the PSHC can be improved by 107% and 540%, respectively, compared with the comparison column. The reinforcement effect will become better with the increase of the hoop ratio. When the prestress ratio increases gradually, the carrying capacity of PSHC increases gradually and the peak strain decreases gradually. The initial axial compression ratio has no obvious influence on the reinforcement effect, the PSHC can be used as a non-unloading reinforcement method. Based on the experiment results, a prediction equation was proposed and verified by the comparison of prediction values and test data in this investigation and other references.