PVC-CFRP管钢筋混凝土柱的偏心受压性能

通过24根聚氯乙烯-碳纤维增强树脂(PVC-CFRP)管钢筋混凝土柱的偏心受压试验,分析了CFRP条带环箍间距和偏心距对PVC-CFRP管钢筋混凝土柱的破坏形态、承载力、应变及荷载-位移关系的影响。试验结果表明:小偏压试件发生混凝土和PVC管的压碎破坏,大偏压试件发生钢筋受拉屈服和PVC管的拉断破坏。随着偏心距和CFRP条带环箍间距的增加,与PVC管钢筋混凝土柱相比,PVC-CFRP管钢筋混凝土试件的承载力逐渐减小,小偏压试件延性系数有不同程度的提高,大偏压试件延性系数基本保持不变。纵向钢筋和混凝土应变发展基本一致,截面受压侧CFRP条带的应变较小,试件截面的应变基本符合平截面假定。试件的荷载-挠度关系和弯矩-曲率关系分为两阶段,CFRP条带环箍间距和偏心距对第一阶段基本没有影响,第二阶段为直线强化段,随着偏心距和CFRP条带环箍间距的增加,强化段的斜率逐渐减小。

Eccentric compression performance of PVC-CFRP confined reinforced steel tube concrete column

The results of experiment investigation of 24 PVC-CFRP confined reinforced steel tube concrete col-umns were presented.The influences of hoop spacing of CFRP strips and eccentricity on the failure mode,bearing capacity,strain and load-displacement of PVC-CFRP confined reinforced steel tube concrete column were studied. The experimental results show that small eccentric specimens take the compressive failure of concrete and PVC tube as a sign,while large eccentric specimens take the tensile yield of longitudinal reinforcement and tensile failure of PVC tube as a mark.Compared with PVC confined reinforced steel tube concrete column,the bearing capacity grad-ually decreases with the increasing hoop spacing of CFRP strips and eccentricity,the ductility coefficient of the small eccentric specimens is improved in different degrees,and the ductility coefficient of the large eccentric specimens re-mains unchanged.The development of longitudinal reinforcement and concrete strain is basically the same,the strain of CFRP strips in the compression side of the cross section is small,and the strain of the specimen section is basical-ly in accordance with the assumption of plane section.The curves of load-deflection and moment-curvature are divid-ed into two stages.The hoop spacing of CFRP strips and eccentricity have no effect on the first stage.The second stage is the straight line segment,and the slope of the second stage gradually decreases with the increment of the hoop spacing of CFRP strips and eccentricity.