Influence of Confinement Interaction on the Compressive Behavior of Steel Tube–Reinforced Concrete Columns

• DOI: 10.1061/jsendh.steng-12295
• Publication Date: 2023-11-17T03:38:05Z
• Authors: Yuan Huang; Hua-Sen Lu; Huanpeng Hong; Xiao-Li Zhang
• Keywords: Axial symmetry

A steel tube–reinforced concrete (ST-RC) column is composed of the inner concrete-filled tube (CFST) component and peripheral reinforced (RC) component. In this study, confinement interaction mechanism axially loaded columns was evaluated experimentally analytically. Eleven specimens were tested, including five ST-RC, three CFST, RC columns. The test results found that between core CFST outer components integrates both advantages while remarkably altering section equilibrium compared with conventional confined concrete. Specifically, following two aspects need to be considered. First, since subjected secondary provided by stirrups, capacity an ST-RC 1.07–1.21 times greater than simple superposition (CFST+RC). Second, for component, because filled-in tube, stirrups cannot effectively activated due weakened dilation Such strain-lagging leads a steeper falling branch load–axial strain curve under compression CFST+RC. Finally, based on modified constitutive models considering in column, well-defined analytical model predicting structural performance established.