Experimental and analytical investigation of the flexural behavior of steel-bamboo composite I-beams with composite connections

A novel steel-bamboo composite (SBC) I-beam with composite connections was presented, in which the pure adhesive bonding steel-bamboo (SB) interfaces at the beam's flanges were reinforced by self-tapping screws (STSs) to avoid the debonding failure and slip behavior of beams. 14 beams with various parameters were prepared and performed four-point bending tests to investigate the bending behavior of beams. The influences of different parameters on the bending behavior were revealed. Finally, analytical models were developed for estimating the interfacial shear stress at the beam flanges in the serviceability limit state (SLS) and ultimate deflection of beams, respectively. The results indicated that the debonding failure and slip behavior of beams were effectively limited, and the flexural and deformation capacities and ductility were significantly improved. The failure mechanism of beams changed from a debonding failure to a bamboo tensile failure. The bending resistance was improved by increasing the diameter and arrangement range of the STS and reducing the STS spacing and steel flange width-thickness ratio. The local buckling behavior was effectively reduced and the ductility was improved for beams reinforced with transverse stiffening ribs (TSRs). Compared to beams with inclined STS reinforced bonding interfaces, the bending resistance was increased for beams with vertical STS reinforced bonding interfaces. The analytical model provided accurate predictions for beams.