纤维增强混凝土对剪压柱塑性铰形成影响的比较试验

针对汶川地震中钢筋混凝土结构出现大量脆性破坏,以改善抗震结构延性为研究目标,对7根具有相同截面和配筋、不同纤维品种和掺量的纤维增强混凝土结构柱进行了低周反复加栽试验,得到了框架柱的剪切荷栽一位移曲线、骨架曲线以及各阶段的荷栽位移值.并据此分析了不同的纤维品种和掺量对混凝土柱延性的影响.试验结果表明,纤维增强混凝土显著改善了剪压柱的延性,延缓了塑性铰的产生.试验数据比较说明,在承受剪压的框架结构柱非线性变形过程中,钢纤维混凝土具有最强的耗能能力,碳纤维混凝土对剪压柱的水平延性提高幅度较大,合成纤维能有效延缓塑性铰的出现,但是对柱端最大承载力提高幅度较小.

Comparison Experiments of the Effects of Fiber Reinforced Concrete on Formation of Plastic Hinge of Shearing Pressure Column

In view of the mass brittle failures of reinforced concrete constructions in Wenchuan earthquake,the ductility of constructions is selected to be the research object,and the cyclic loading experiments are carried out on 7 concrete shearing pressure columns with different fiber types and dosages but with same cross-section and reinforcements.After that,the shearing load-displacement curve and the skeleton curve of the frame column are attained,as well as the load-displacement value of each step.Based on these data,the effects of different fiber types and dosages on the ductility of concrete shearing pressure columns is analyzed.The results show that the ductility of fiber reinforced concrete structural columns is improved significantly and the production of plastic hinges is delayed.Experimental data show that in the nonlinear deformation process of shearing pressure column,the steel fiber reinforced concrete has the strongest energy dissipation capacity,the carbon fiber reinforced concrete can improve ductility of the column,the synthetic fiber can effectively delay the emergence of plastic hinges,but the maximum capacity to end-column improves less extent.