圆形箍筋约束混凝土力学性能尺寸效应试验

为了考察约束混凝土轴压力学性能的尺寸效应，对10组圆形箍筋约束混凝土短柱进行了单调轴压试验，在试验基础上对比分析了试件几何尺寸对试件破坏特征，承载能力及变形能力的影响。试验结果表明：峰值应力随试件尺寸的增大而下降，且体积配箍率越低，下降趋势越明显；无保护层试件的峰值轴向应变、峰值环向应变以及峰值后变形能力也随试件尺寸的增大呈下降趋势；当体积配箍率较低时，保护层的存在使试件极限承载力有所提高，且大尺寸试件的提高幅度偏大；而当体积配箍率较高时，保护层对试件极限承载力贡献很小。

Experimental on size effect of compressive response of concrete confined by circular hoops

The monotonic axial compression test was performed on ten groups of short columns confined with circular hoops to investigate the size effect of the mechanical properties of confined concrete under axial compressive loading. Based on the result of the experiment,the failure characteristic,ultimate strength and deformation capacities of various specimens were comparatively analyzed.The test result shows that： (1) As the size of the specimen increases, the peak strength decreases, and the lower the volumetric ratio,the more obvious the decreasing trend. (2) As the size of the specimen without concrete cover increases, the axial strain, the hoop strain and the ductility become weaker. (3) The ultimate strength of the specimen with lower volumetric ratio of transverse reinforcement increases due to the existence of the concrete cover, and the strength of the specimen with bigger size increases more. When the volumetric ratio of transverse reinforcement is high, the contribution of the concrete cover on the ultimate strength of the specimens is very little.