Experimental study and numerical analysis of the interfacial bonding performance of T‐shaped concrete‐filled steel tubes

Summary

The effects of core concrete strength (C30, C40, and C50), steel tube length (600, 1000, and 1400 mm), and steel tube wall thickness (3, 4, and 5 mm) on the bonding performance of T‐shaped concrete‐filled steel tubes (CFSTs) were systematically investigated using push‐out test. Via the test, the patterns of the failure modes, load‐slip curves, stress‐slip curves, and distribution law of longitudinal strain were observed for the specimens, and the bond‐slip constitutive model for T‐shaped CFSTs was established. The test results indicate that the bond stress of T‐shaped CFSTs increases with the increase in concrete strength and tube wall thickness, while the steel tube length has less influence on the bond stress. In addition, non‐linear spring elements were used to simulate the interfacial bonding behavior based on the bond‐slip equation, which is in good agreement with the experimental curve results.