Axial compressive behaviour and design calculations on recycled aggregate concrete-filled steel tubular (RAC-FST) stub columns

•A series of axial compression tests of 32 RAC-FST stub columns were conducted.•The passive confinement effect in RAC-FST was thoroughly evaluated and the constitutive model of RAC in RAC-FST was suggested.•A 3-D refined finite element analysis (FEA) model was established, and parametric analysis was successively carried out.•Based on the reliability analysis, a simplified model and the corresponding partial factors were proposed.