Confinement effectiveness of bamboo scrimber-filled steel tube columns under axial compression

Abstract

Bamboo scrimber-filled steel tube (BSFST) columns, consisting of external steel tubes and inner bamboo scrimber, are expected to improve the strength and deformation ability of bamboo scrimber while maintaining excellent performance characteristics, such as light weight, high strength and environmental friendliness. Thirty bamboo scrimber columns and thirty BSFST columns were tested under axial compression to investigate the confinement effectiveness of BSFST columns. During the test, only the core bamboo scrimber bears the axial compression, and the main parameters to be considered are specimen size and steel tube thickness. The results show that the stress‒strain relation curve of the BSFSTs can be divided into an elastic stage and an elastic‒plastic stage, and the BSFSTs showed obvious stress hardening behavior in the elastoplastic stage. With increasing steel tube thickness, the bearing capacity, ultimate stress and ultimate strain of the specimens increase greatly. Finally, the calculation equations for the ultimate stress and ultimate strain of BSFST and the complete stress‒strain curve models of BSFST were proposed. The proposed model can accurately predict the complete stress‒strain behavior for BSFST columns.