Experimental Research on Interface Bonding Performance of Concrete-Filled Aluminum Tubular Columns at Room Temperatures

In order to study the interface bonding performance of concrete-filled aluminum tubular columns at room temperatures, three factors including concrete strength and component slenderness ratio were considered. A bond-slip push-out test was conducted on concrete-filled aluminum tubular stub columns, and the load-slip correlation, and longitudinal strain distribution of aluminum tubes under different loads were obtained. The feasibility of existing constitutive models for bond-slip of concrete-filled steel tube columns in evaluating the peak bonding strength and residual bonding strength of concrete-filled aluminum tubular concrete columns was analyzed. The research results indicated that the trend of the load-slip curve of each specimen was basically consistent; the longitudinal strain on the surface of the aluminum tube was proportional to its distance from the loading end, and the bonding stress was uniformly distributed within the interface length range; the decrease in concrete strength and interface bonding length would lead to a decrease in ultimate bonding strength and residual bonding strength, and the impact of concrete strength was greater. On this basis, a calculation formula for the interfacial bonding strength of concrete-filled aluminum tubular columns at room temperatures was proposed.