内置十字形截面钢骨-GFRP 管约束混凝土短柱核心混凝土约束效应研究

Using cross-shaped steel in FRP-confined steel-reinforced square columns can achieve hybrid confinement of the inner concrete, which enhancing the composite effect of the composite columns. Axial compression tests were conducted on short GFRP-confined steel-reinforced square columns with flange-broadened cross-shaped steel. The test parameters included the column forms, the thickness of the FRP tube, and the size of the cross-shaped steel. The research results show that the flange buckling has a minimal effect on the axial load-bearing capacity. The composite columns exhibit excellent axial load-bearing capacity and axial deformability. Compared with the GFRP-confined plain concrete columns, the peak stress of the confined concrete increases by 56. 51%, and the ultimate strain exceeds 2. 7%. Increasing the thickness of the FRP tube, the height of the steel section, the width of the flange, as well as the thickness of the flange and web can improve the axial peak stress of the confined concrete. When the width of the flange increases from 60 mm to 180 mm, the peak stress increases by 18. 38%.