FRP筋材加固矩形截面混凝土柱的极限强度分析

Ultimate Strength Analysis of Damaged Reinforced Concrete Columns Strengthened with FRP

采用外贴FRP法加固矩形截面混凝土柱,能够有效约束受压状态下矩形截面混凝土柱的侧向变形。以FRP约束混凝土矩形短柱为研究对象,基于ABAQUS有限元软件,构建CFRP约束矩形截面混凝土柱轴压试验模型,分析混凝土柱应力-应变曲线,并与已有试验进行对比;在此基础上,结合侧向约束强弱界限的判定标准,推导出修正的FRP加固矩形截面混凝土柱的应力-应变关系模型。研究表明:当混凝土处于弹性状态,其横向膨胀变形很小,FRP提供的约束力较小;当约束混凝土应力超过未约束峰值应力,混凝土进入塑性状态,FRP筋材提供的约束力逐渐增大,其承载力和变形能力产生较大幅度增加。FRP对矩形截面混凝土柱的约束作用改善了构件的延性,提高了构件的承载力。

Strengthening the rectangular section concrete column with an externally bonded FRP method can effectively restrain the lateral deformation of concrete columns under rectangular compression.FRP confined rectangular concrete short column as the research object,based on the ABAQUS finite element software,build CFRP confined rectangular concrete column axial compression test model,analysed of the concrete stress-strain curve,and compared with the existing test;on this basis,combined with the standard lateral restraint of strong and weak boundaries,set up the stress-strain model derived from the modified FRP reinforced concrete columns with rectangular section.The results show that:when the concrete is in the elastic state,the horizontal expansion deformation is very small,and FRP binding is small;when the stress exceeds the unconstrained concrete peak stress,the concrete enters the plastic state,the binding force of the FRP bars increases gradually,and the bearing capacity and deformation capacity are greatly increased.The confinement of FRP to the rectangular section concrete column improves the ductility of the component and improves the bearing capacity of the member.