长轴短轴比对椭圆形GFRP约束混凝土轴压性能的影响

Effects of the long-axis and short-axis ratio on the axial compressive behavior of elliptical GFRP-confined concrete

纤维增强树脂基复合材料(FRP)能够有效地提高圆形FRP约束混凝土柱的强度和延性。在矩形FRP约束混凝土柱中,由于FRP对核心混凝土的约束不均匀,FRP约束效果较差。为了给核心混凝土提供有效的约束,可将矩形截面优化成椭圆形截面,再应用FRP进行约束。通过椭圆形玻璃纤维增强树脂基复合材料(GFRP)约束混凝土的轴压性能试验,试件的长轴尺寸为300 mm,高度为600 mm,研究长轴短轴比(1.0、1.2、1.5和2.0)和GFRP厚度对椭圆形GFRP约束混凝土轴压性能的影响。结果表明:长轴短轴比对于核心混凝土的强度和延性有较大的影响;GFRP厚度越厚,约束混凝土的强度越高,延性越好。

The strength and ductility of circular fiber reinforced polymer(FRP)-confined concrete could be effectively enhanced due to the confinement of FRP.However,the confinement effect for rectangular FRP-confined concrete is much lower due to the non-uniform expansion of the core concrete.In order to provide effective confinement for the core concrete,the rectangular cross-section could be modified into elliptical shape for better FRP confinement.The axial compressive tests were conducted to the elliptical glass fiber reinforced polymer(GFRP)confined concrete columns.The specimens had a long-axis of 300 mm and a height of 600 mm.Effects of long-axis and short-axis ratios(1.0,1.2,1.5 and 2.0)and GFRP thickness on the axial compressive behavior of elliptical GFRP-confined concrete were investigated.Results showed that the long-axis and short-axis ratio had a significant effect on the strength enhancement and ductility of the confined concrete.The strength and ductility of confined concrete increased with the increasing of GFRP thickness.