喷射FRP加固震损钢筋混凝土柱抗震性能试验

Test of seismic performance of earthquake damaged reinforced concrete columns strengthened with sprayed FRP

通过12组72件喷射纤维/树脂复合材料(FRP)试样的拉伸强度试验,研究了纤维种类、树脂基体材料、纤维体积分数、纤维混杂比及纤维长度等因素对喷射FRP拉伸强度、弹性模量和断裂伸长率等性能的影响。通过8根钢筋混凝土(RC)柱试件的拟静力试验,研究了喷射玄武岩纤维/树脂复合材料(BFRP)和混杂玄武岩-碳纤维/树脂复合材料(BF-CFRP)加固震损RC柱的抗震性能,分析了喷射FRP层厚度、纤维混杂比、柱预损程度和柱轴压比等对加固试件的极限承载力、抗侧变形能力、刚度退化特征和滞回特性的影响。结果表明:玻璃纤维与乙烯基酯树脂基体的协同工作性能最优,而玄武岩纤维具有耐久性高、延性好、与乙烯基酯树脂基体协同工作性能好等优良性能,可以作为玻璃纤维的良好替代品;玄武岩纤维混杂少量比例的碳纤维作为树脂基体增强材料,可以有效提高喷射FRP的拉伸强度和变形性能;震损RC柱经喷射FRP加固后,可以基本恢复其震损前设计极限承载力,并有效提高其延性和耗能能力。该加固方法可以对地震区已震损RC柱进行快速加固,有效防止整体结构在余震中发生倒塌等严重破坏。

Based on the tensile strength tests of 12 groups of 72 pieces of sprayed fiber reinforced polymer （FRP） specimens,the effects of factors such as fiber type,resin matrix material,fibers volume fraction,hybrid ratio of fi-bers and fiber length etc.on the properties such as tensile strength,elastic modulus and elongation at break etc.of sprayed FRP were investigated.The seismic performance of earthquake damaged reinforced concrete （RC）columns specimens strengthened with sprayed basalt fiber reinforced polymer （BFRP）and hybrid basalt-carbon fiber rein-forced polymer （BF-CFRP）was investigated by the quasi-static test of 8 RC columns,and the influences of the thickness of sprayed FRP layer,hybrid ratio of fibers,pre-damage degree of columns and the axial compression ratio of column etc.on the ultimate load capacity,lateral deformation resistance,degradation characteristics of stiffness and hysteresis properties of the strengthened specimens were analyzed.The test results show that the cooperative working performance of glass fiber and vinylester matrix is the best,and basalt fiber can be used as a favorable suc-cedaneum of glass fiber because of its excellent performance of high durability,good ductility and good cooperative working performance with vinylester matrix;hybrid basalt fibers with small amount of carbon fibers used as rein-forcement for resin matrix can effectively increase the tensile strength and deformation performance of sprayed FRP;earthquake damaged RC column can almost be rehabilitated to its designed ultimate load capacity before the earth-quake damage by strengthening with sprayed FRP,and both the ductility and the ability of energy dissipation can be effectively enhanced.This strengthening technique can fast strengthen the earthquake damaged RC column in seis-mic area and effectively hinder the collapse of whole structures exposed to the aftershock and other heavy damages.