FRP筋/珊瑚混凝土柱轴心受压承载力

Compression behavior of FRP bars/coral concrete columns under axial compression loading

对8根塑料纤维增强树脂复合材料(FRP)筋/珊瑚混凝土轴心受压柱和1根钢筋/珊瑚混凝土轴心受压柱进行了承载能力试验,试验参数包括配筋率、箍筋间距、长细比和筋材种类。结果表明:相同配筋率下,FRP筋/珊瑚混凝土柱和钢筋/珊瑚混凝土柱的破坏机制不同,但受力性能良好;相同构件尺寸下,增大纵筋直径导致纵筋与混凝土保护层的黏结性能降低;减小箍筋间距有利于提高构件的延性;长细比越大的构件承载力越低。然后,基于筋材压缩性能试验的数据分析及参考文献的对比探讨,建议碳纤维增强树脂复合材料(CFRP)筋名义屈服强度取值为0.34f_(y)(f_(y)为筋材的极限抗压强度),对应的理论值与试验结果相近,从而提出适用于CFRP筋/珊瑚混凝土柱的理论计算公式,为工程实践提供参考依据。

The axially loaded bearing capacity tests on 8 fiber reinforced polymer(FRP) bar/coral concrete columns and 1 steel bar/coral concrete column were carried out. Parameters such as reinforcement ratio, stirrup spacing,slenderness ratio and reinforcement type were discussed. The results show that the failure mechanism of FRP reinforced coral concrete column and steel bar/coral concrete column is different, but the mechanical performance is still good. Increasing the diameter of longitudinal reinforcement leads to the decrease of bonding performance between longitudinal reinforcement and concrete protective layer. Reducing the spacing of stirrups is beneficial to improve the ductility of the members, and the higher the aspect ratio, the lower the bearing capacity of the members. Then, based on the data analysis of the compression performance experiment and the comparison of references, it is suggested that the nominal yield strength of carbon fiber reinforced polymer(CFRP) reinforcement should be 0.34 f_(y)(f_(y) is the ultimate compressive strength of the reinforcement), and the corresponding theoretical value is similar to the experimental results. Finally, the theoretical calculation formula for bearing capacity of CFRP/coral concrete axial compression column is put forward, which provides a reference for engineering practice.