Experimental investigation on bond-slip behavior of self-compacting rubberized concrete-filled steel tubes

The bond strength between materials is the basis of the cooperative work of composite structures. This study aims to investigate the bonding performance of push-out tests conducted on self-compacting rubberized concrete-filled steel tubes (SCRCFST). The rubber content, particle size, interface bonding length, and water-cement ratio were varied to evaluate their impact on bond strength. The failure mode and failure mechanism were analyzed. The bond damage and energy consumption capacity were investigated. Moreover, this study reveals the characteristics of the stress-slip curve and derives the characteristic equations from reviewing the different points. Test results indicate that rubber particles enhance the energy dissipation capacity of specimens after reaching ultimate bond strength. Furthermore, bond strength decreases with the increase of rubber particles size and water-cement ratio, while the bonding length is barely impacted. It is worth noting that the bonding strength increases slightly at 10% rubber content. The main contribution of this work is to fill the gap in the bonding performance of SCRCFST and guide engineering utilization.