加固采用尼龙、芳纶和聚脂纤维丝混杂而成的层内混杂布(inner hybrid fiber reinforced plastics,IHFRP).通过IHFRP布约束混凝土圆柱体、棱柱体的轴压试验,研究了其破坏形态、应力-应变全曲线、峰值应力、峰值应变、弹性模量、延性.试验结果表明,与无纤维布相比,有3、4层布的试样的抗压强度和峰值应变均提高;纤维布层数相同时,圆柱体试件的抗压强度、峰值应变比棱柱体试件高;与零倒角相比倒角半径增大,棱柱体试件的峰值应力和峰值应变有不同程度提高.采用压缩韧性指数对约束柱的延性进行评价,加固柱韧性指数I20高,接近理想弹塑性材料,非常有利于结构抗震耗能.
Inner hybrid fiber reinforced plastics(IHFRP) sheets fabricated by PA,PET,and PPTA intermixing are adopted.Based on the experiment of concrete circular and quadrate columns confined by IHFRP under axial compression,failure configuration,stress-strain curve,bearing capacity,peak strain,elastic modulus,and ductility of such concrete columns are analyzed.Compared with the specimen without IHFRP,the bearing capacity and peak strain of the speciments with three or four layers of IHFRP are improved,respectively;With equal layers of fiber,the bearing capacity and peak strain of circular columns are higher than those of quadrate columns.With increasing radius at the corners augmenting,the bearing capacity and the peak strain of quadrate columns are improved at different levels.The ductility of concrete columns confined by IHFRP is estimated with the toughness index,which is figured with an area ratio of the load-compression strain.The I20 of the confined columns is high,which indicates that there is excellent ductility at the latter reacting stage of concrete columns confined by IHFRP,and frame is better for seismic energy dissipation.