锈蚀箍筋约束混凝土的单轴受压试验与本构关系模型

Uniaxial Compression Experiment and Constitutive Model for Concrete Confined by Corroded Hoops

为了研究揭示锈蚀箍筋约束混凝土的单轴受压特性,基于36组锈蚀箍筋约束混凝土试件的单轴受压试验,获得了不同锈蚀程度箍筋约束混凝土的应力—应变曲线试验数据,分析了箍筋质量锈损率对约束混凝土的峰值应力、峰值点应变、极限应变以及破坏形态的影响规律,并分别建立相应的计算模型,进而研究提出了锈蚀箍筋约束混凝土的单轴受压本构关系模型。结果表明:随着箍筋质量锈损率的增加,约束混凝土的峰值应力、峰值点应变和极限应变逐渐降低;箍筋体积配箍率越小,箍筋质量锈损率对峰值应力和极限应变的影响越显著;当箍筋质量锈损率分别超过15%、10%和30%左右时,大部分方形箍、棱形箍和螺旋箍在试件轴压破坏位置处发生断裂;锈蚀箍筋约束混凝土单轴受压本构关系模型的计算值与试验数据吻合较好,说明该模型能够合理描述箍筋锈蚀程度对约束混凝土单轴受压应力—应变曲线的影响规律。

In order to explore the uniaxial compression behavior of concrete specimens confined by cor‑roded hoops,the stress-strain curve test data of uniaxial compression test for 36 sets of concrete speci‑mens with different corrosion levels were obtained based on the uniaxial compression test of 36 sets of concrete specimens confined by corroded hoops.The influences of the mass loss ratio of hoops on the peak stress,peak strain,ultimate strain,and failure pattern of concrete specimens confined by corrod‑ed hoops were analyzed,while the computation models for the peak stress,peak strain,and ultimate strain of concrete confined by corroded hoops were developed respectively.Finally,the constitutive model of concrete confined by corroded hoops under uniaxial compression was established.The analysis results show that the peak stress,strain at peak stress,and ultimate strain gradually decrease as the mass loss ratio of hoops increases.The mass loss ratio of hoops affects the peak stress and ultimate strain more significantly when the volumetric ratio of hoops is lower.When the mass loss ratio of hoops exceeds 15%,10%,and 30%,most of the square,prismatic and spiral hoops were broken at the axial compression failure position of specimens,respectively.The calculated results of the pro‑posed uniaxial compression constitutive model of concrete confined by corroded hoops agree well with the experimental data,which indicate that it can reasonably describe the influence of corrosion degree of hoops on the uniaxial compressive stress-strain curve of confined concrete.