Investigation on Bond Behavior between Self-compacting Rubberized Concrete and Rectangular Steel Tubes

The combination of self-compacting rubberized concrete (SCRC) and rectangular steel tubes to be a composite structure is a new attempt to apply it to a broader range of engineering fields while making up for the shortcomings of SCRC. This study presents experimental and analytical studies on the bonding behavior of rectangular self-compacting rubber concrete-filled steel tubes (SCRCFST). A total of 17 SCRCFST specimens were performed on push-out test with different parameters of 1) interface bonding length, 2) rubber aggregate replacement rate, 3) rubber particle size, and 4) water-cement ratio (W/C). Based on the failure mode, strain analysis, and the evolution of damage on the interface between the SCRC and steel tubes, test results determined the effects of the parameters, and a prediction equation for the bond strength was derived from developing a relationship of bond-slip. The results indicated that the increase of rubber content, rubber particle size, W/C harmed the bond strength of SCRCFST, and bond length had little effect on bonding strength. Furthermore, the strain distribution of the rectangular steel tube was not uniformly distributed. The achievement of this research is the investigation of the bonding properties of the new structure, to provide guidance for future research scholars.