CFRP布对不同截面混凝土柱加固性能分析

为了探究碳纤维增强复合材料(CFRP)布对不同截面混凝土柱的加固性能,以条带用量、条带净间距、条带净宽等参数为控制变量,设计并制作了3组钢筋混凝土柱,第1组试件为方形截面柱,第2组试件为T形截面柱,第3组试件是在第2组试件的基础上,在翼缘与腹板转角处利用角钢对CFRP布进行锚固。通过对3组钢筋混凝土试件进行轴心受压试验,得到了试件极限荷载、轴向变形以及破坏形态等试验数据。采用有限元软件ABAQUS建立了一批CFRP布约束状态下的混凝土短柱,并对其力学性能进行了分析。根据试验数据及有限元分析结果,提出了CFRP条带约束状态下方形截面钢筋混凝土柱和角钢锚固CFRP条带约束状态下T形截面钢筋混凝土柱极限承载力的计算公式。结果表明:随着CFRP条带用量的增加,加固混凝土柱的承载力增大; 当CFRP条带的用量相同时,极限承载力随条带净间距的减小而增大; 使用角钢在T形截面柱的翼缘与腹板转角位置对CFRP条带锚固,可以更好地发挥出CFRP条带的抗拉强度,使混凝土柱的极限承载力有所提升。

Analysis of reinforcement performance of CFRP strips on concrete columns with different cross-sections

In order to explore the reinforcement performance of carbon fiber reinforced polymer(CFRP)strip on concrete columns with different cross-sections, three groups of reinforced concrete columns were designed and fabricated with parameters such as strip amount, net spacing and net width of strips as control variables. The first group of specimens was a square section, the second group of specimens was a T-shaped section, the third group of specimens was based on the second group of specimens, and angle steel was used to anchor CFRP sheets at the corner of flange and web. Axial compression tests were carried out on three groups of reinforced concrete specimens, and the ultimate load, axial deformation and failure mode of the specimens were obtained. Based on the experimental data, a number of concrete short columns confined by CFRP strip were established by finite element software ABAQUS, and their mechanical properties were analyzed. According to the experimental data and finite element analysis results, the calculation formulas of ultimate bearing capacity of square section reinforced concrete columns and T-shaped section reinforced concrete columns confined by CFRP strips and angle steel anchored CFRP strips were proposed. The results show that the bearing capacity of reinforced concrete columns increases with the increase of CFRP strip usage. When the amount of CFRP strips is the same, the ultimate bearing capacity increases with the decrease of the net spacing of the strips. The use of angle steel to anchor CFRP strips at the flange and web corners of T-shaped columns can better exert the tensile strength of CFRP strips and improve the ultimate bearing capacity of concrete columns.