碳纤维布加固薄壁钢管再生混凝土短柱力学性能的试验研究

针对四川地震中产生的大量废弃建筑骨料,设计了10个薄壁钢管再生混凝土短柱的轴压性能试验,其中6个试件采用外贴碳纤维复合材料(CFRP)进行加固,研究不同加固形式对薄壁钢管再生混凝土短柱的极限承载力,变形能力,刚度和破坏形态的影响。试验分析了不同再生骨料替代率,钢管截面形式和加固面积比,以及钢管长径比对加固效果的影响。试验结果表明,2种加固方式均可显著提高薄壁钢管再生混凝土短柱的极限承载力和变形能力,改变其破坏模式和提高其整体刚度。碳纤维加固面积比越大,试件极限承载力和变形能力提高幅度越大,但其提高程度并不与加固面积成正比。对于不同长径比的薄壁钢管再生短柱,不同加固方式对其加固效果差别不大。

tructural behaviour of steel tube short columns filled with recycled aggregate concrete and externally strengthened with CFRP sheets

In order to make use of the recycled aggregate concrete from the collapsed structures in Sichuan earthquake on 12 May 2008, ten short steel tube columns filled with normal concrete and recycled aggregate concrete (RAC) were fabricated and tested to investigate the effects of the load carrying capacity, deformability and stiffness of the steel tube columns reinforced by carbon fibre reinforced polymer (CFRP) sheets. The main experimental parameters included the portion of the recycled aggregate concrete used, the cross section type of the columns, the reinforcement ratio of CFRP and the length to diameter ratio. The results show that the ultimate load carrying capacity and deformability of the short columns could be increased greatly by two reinforcing arrangement, i.e. full wrapping arrangement and partial wrapping arrangement. The results also show that the more of CFRP reinforcing ratio, the higher of ultimate load carrying capacity and deformability, but the enhancement ratio is not in proportion to the CFRP reinforcement ratio. In addition, the stiffness of the steel tube columns strengthened was enhanced more significantly in the columns with full wrapping arrangement than that of with partial wrapping one. Finally, the result indicated that the length to diameter ratio had a little influence on the load carrying capacity of the steel tube columns with CFRP reinforcement.