Abstract:The development of laminated-bamboo has broadened the applications of bamboo material in structural engineering. An assembling composite hollow column parallel to the fiber texture is composed of square thin-walled cold-formed steel tube/bamboo plywood reinforced by transverse binding bars and structural adhesive. The thin-walled steel-tube/bamboo plywood assembling composite hollow columns with binding bars (SBCCBs) are a new type of steel/bamboo composite with excellent physical and mechanical properties. Multi-layered high-strength bamboo plywood forms the primary body in an SBCCB that is subjected to forces, while the square thin-walled steel tube serves as a liner. Large numbers of bamboo are used, which reduces the manufacturing cost of the composite columns and results in a relatively high load-bearing capacity. Nine thin-walled SBCCBs were used to perform low-cyclic reversed quasi-static loading tests, and their damage process and failure modes were investigated. The influence of the shear-span ratio, net cross-sectional area, sectional combination mode of SBCCBs on the bearing capacity, and seismic behavior were analyzed. The results indicate that the failures of SBCCBs are primarily the cracking damage between the gluing interfaces and the fracture damage of plywood material at the foot of column. The sectional combination mode had a significant influence on the failure mode, and the seismic behavior of SBCCB can be improved by increasing the net cross-sectional area and slenderness ratio of the composite hollow columns. SBCCBs have good elastic deformation and seismic energy dissipation capacities, and the binding bars can effectively guarantee the integrity of SBCCB and suppress the gluing failure between the matrix interfaces. SBCCB specimens showed an excellent seismic performance and can be used as the vertical bearing element of a multi-story, pre-fabricated, column-supported, and bamboo-framed wood building.
