论文部分内容阅读
为了考察约束混凝土轴压力学性能的尺寸效应,对两个系列的圆形箍筋约束混凝土圆柱试件进行了单调轴压试验,主要试验变量为体积配箍率和试件几何尺寸,试件的最大直径为576 mm。试验结果表明,约束混凝土的峰值应力和峰值应力对应应变均随试件尺寸的增大呈下降趋势,而变形能力与试件尺寸的关系不够明确。利用析因分析法对试验数据进行分析,发现体积配箍率对箍筋约束混凝土的峰值应力、峰值应力对应应变和变形能力均有显著影响。试件几何尺寸对峰值应力及对应应变的影响较为显著,但对试件变形能力的影响不明显。体积配箍率与试件几何尺寸的交互作用对峰值应力、峰值应力对应应变和变形能力的影响均不显著。基于试验、分析结果,建立了针对圆形箍筋约束混凝土的应力-应变本构关系模型,模型预测值与本文试验结果吻合较好。
In order to investigate the size effect of confining the axial compressive properties of concrete, two series of circular cylindrical stirrup specimens with circular stirrup restraint were subjected to a monotonic axial compression test. The main experimental variables were volumetric stirrup ratio and specimen geometry. The maximum diameter is 576 mm. The experimental results show that the corresponding strain of peak stress and peak stress of restrained concrete all decrease with the increase of specimen size, while the relationship between deformation capacity and specimen size is not clear enough. The analysis of the experimental data by factorial analysis shows that the volume fractional hoisting rate has a significant effect on the peak stress, peak stress corresponding strain and deformation capacity of the confined concrete. The influence of the specimen geometry on the peak stress and the corresponding strain is significant, but the effect on the deformation capacity is not obvious. The interaction between the volumetric ratio of the stirrup and the specimen geometry has no significant effect on the peak stress, the corresponding strain and deformation capacity of the peak stress. Based on the test results and the analysis results, a stress-strain constitutive model was established for the concrete with circular stirrup restraint. The predicted values of the model agree well with the experimental results.