Axial compressive performance and design model of fiber wound GFRP tube confined concrete

54 fiber-wound GFRP tube confined concrete cylindrical specimens classified in eighteen groups were designed and manufactured, and the parameters included the number of fiber layers (6, 10), fiber angle ($ \pm 45^\circ $, $ \pm 60^\circ $, $ \pm 80^\circ $), slenderness ratio (2, 4) and compression section (full section, core concrete). Based on the axial compression test results, a design-oriented peak stress prediction model in terms of fiber angle was proposed. The results show that GFRP tube can effectively improve the strength and ductility of confined specimens. The peak strength of the specimen increases with the increase of fiber angle and layer number, and the increase of the peak strength of the specimen with large slenderness ratio is larger. The full section compression will adversely affect the circumferential properties of the confined specimen. The confined pattern is mainly determined by the fiber angle. The specimens with ±60° and ±80° angles are strong confinement, and reveal brittle failure mode. The specimens with ±45° angle are weak confinement, and reveal ductile failure mode. By studying the mathematical relationship between the peak strength and the effective confinement strength, the simplified design-oriented model was derived, which has sufficient precision for solving the peak strength of specimens with different fiber angles, and can provide reference for relevant engineering applications.