钢筋混凝土矩形柱外包CFRP的轴压比限值分析

Analysis on Critical Value of Axial Compression Ratio for Rectangular RC Column Confined by CFRP

钢筋混凝土矩形柱外包碳纤维后,其强度和延性均得到提高,但随着偏心距的增大,强度提高幅度逐渐降低,而延性仍较高。本文基于混凝土偏心受压外包CFRP后的受力特性,给出柱截面受压区对应的应力-应变关系,推导出钢筋混凝土矩形柱外包CFRP后的轴压比限值计算公式,文中还给出了工程算例。该方法可以作为轴压比不满足现行规范要求的混凝土柱外包CFRP加固设计参考。

The strength and ductility of RC columns with rectangular section wrapped by CFRP can be improved, but the elevated extent of strength decreases with the increase of initial eccentricity of section, and the ductility still remains. Based on the characteristics of concrete section confined by CFRP under eccentric loading, this paper presents the stress-strain relationship of compressed section, and deduces the calculating formula of critical value of axial compression ratio for rectangular RC columns confined by CFRP. An example of related engineering is provided, and this method can be referred by strengthened design for concrete column dissatisfying the active code requirements due to high axial compression ratio.