高强箍筋约束高强混凝土轴心受压应力-应变全曲线研究

为研究高强箍筋约束高强混凝土的受压力学性能，进行了高强箍筋约束高强混凝土棱柱体试件的轴心受压试验，分析了配箍率、箍筋屈服强度和箍筋形式对约束高强混凝土应力-应变曲线的影响。结果表明：高强箍筋在约束混凝达到其峰值应力时并未屈服，根据其受力机理提出了有效侧向应力和相应的高强箍筋应力的计算方法；高强箍筋可在约束混凝土应力-应变曲线下降段提供更有效的侧向约束，曲线下降较为平缓。在试验研究和理论分析的基础上，提出了约束高强混凝土的强度和变形的计算式，建议了高强箍筋约束高强混凝土的应力-应变全曲线方程，理论曲线与实测曲线吻合较好。

Study on stress-strain relationship of high-strength concrete confined with high-strength stirrups under axial compression

In order to investigate the compressive behavior of high-strength concrete confined with high-strength stirrups, high-strength concrete prism specimens confined with high-strength stirrups were tested under axial compression. The effects of three variables such as stirrup ratio, stirrup yield strength and stirrup configuration were analyzed. It is shown that high-strength stirrups do not yield at peak stress of confined concrete. The calculation method for effective lateral stress and actual stirrups stress were suggested based on the stress mechanism. The high strength stirrups can provide more effective lateral stress after the peak stress, which makes the descending section more gentle for stress-strain curve of confined concrete. Based on test results and theoretical analysis, the equations for calculating the strength and strain of confined high-strength concrete were proposed, the formula of stress-strain curve were suggested. It is shown that the theoretical stress-strain curves are in good agreement with the experimental curves.