倒角半径与加载速率对FRP弱约束方形混凝土柱的承载能力影响

The effect of corner radius and strain rate on the compressive strength of FRP weakly confined square concrete

为研究倒角半径和应变速率对纤维增强复合材料(FRP)弱约束混凝土方柱抗压强度的影响规律,对20个FRP弱约束混凝土方柱进行了不同加载速率的轴压试验,探讨混凝土柱倒角半径和应变速率对FRP约束混凝土力学性能的影响,并绘制了相应的应力-应变关系曲线。结果表明:随着试件倒角半径的增加,FRP弱约束混凝土的抗压强度呈现增大的趋势;随着应变速率的增大,FRP弱约束混凝土的抗压强度也呈现增大的趋势;并采用试验结果对现有的抗压强度模型进行评估,发现不同加载速率下FRP强约束混凝土圆柱的抗压强度模型可以用于预测不同加载速率下FRP弱约束混凝土方柱的抗压强度。

Fiber-reinforced polymer(FRP)has been widely used in repair or confinement concrete column.However,most of research has been conducted on the mechanical behavior of FRP strong confined circular concrete.Few studies had focused on the mechanical behavior of FRP weakly confined square cylinder.In order to study the influence of the corner radius ratio and strain rate on the compression mechanical properties of FRP weakly confined square cylinder,an experiment of 20 specimens with different corner radius was carried out under different strain rates.The typical stress-strain curves were drawn based on the test data.The test results show that the compressive strength of FRP weakly confined square cylinder increased with the increase of both corner radius ratio and strain rate.The test results are used to evaluate the existing compressive strength model,and it was found that the existing compressive strength model can be used to predict the compressive strength of FRP weakly confined square concrete under different loading rates.