偏心受压箍筋约束混凝土柱正截面承载力计算方法

Calculated method for bearing capacity of confined concrete under eccentric compression

为考察约束混凝土柱偏心受压性能,收集了16个该类柱的试验结果。这16个试件的混凝土抗压强度为45.1MPa^84.2MPa,箍筋屈服强度为323MPa^1120MPa,箍筋直径为6mm^8mm,箍筋间距为40mm^75mm,体积配箍率为1.81%~3.1%。发现约束混凝土偏心受压承载力试验值较不考虑箍筋约束效应影响的计算值高,且高出幅度随体积配箍率的增大而增大。发现基于高于峰值压应变后认为压应力水平不变的约束混凝土受压应力-应变关系,按《混凝土结构设计规范》(GB 50010—2010)所得约束混凝土柱偏心受压承载力计算值与试验值吻合良好。

In order to observe the mechanical behavior of confined concrete columns under eccentric compression,the test results of 16 confined concrete columns are collected with unconfined compressive strength ranging from 45.1 MPa to 84.2 MPa,stirrup yield strength ranging from 323 MPa to 120 MPa,stirrup diameter ranging from 6 mm to 8 mm,stirrup spacing ranging from 40 mm to 75 mm,volumetric ratio ranging from 1.81%to 3.1%.It is founded that the experimental values of bearing capacity of confined concrete columns under eccentric compression are higher than the calculated values ignoring the stirrup restraint effect,and the height rate increases with the increase of stirrup volumetric ratio.It is also observed that,based on the confined concrete stress-strain relationship which indicates that the concrete stress remained constant after the concrete strain exceeded peak strain.The calculated values of bearing capacity of confined concrete columns under eccentric compression according to GB50010-2010 Code for design of concrete structures are in good agreement with the experimental values.