Abstract

Concrete-filled steel tubes (CFSTs) offer a rapid and cost-effective construction method, providing superior strength and stiffness compared to reinforced concrete and structural steel. This study aims to enhance the performance of the CFST column embedded connection in reinforced concrete footings under cyclic loads using implanted rebars. The FEM program ANSYS 2023 R1 was employed for numerical analysis. The results demonstrate that the incorporation of implanted rebars within the critical section of the connection increases the moment capacity by a factor of 1.1-1.5 and ductility by a factor of 1.05-1.35, based on the reinforcement ratio and the rebars' development length inside the concrete core of the CFST column. These improvements are achieved while maintaining the same main characteristics, such as the diameter-to-thickness (D/t) ratio and the grade of both steel and concrete. These findings suggest a promising approach for improving the connection strength without incurring additional costs.



Keywords: CFST; Cyclic load; Filled Tubes; Tubular column; Base joint; Embedded connection; Finite element modeling; Micro-plane model; coupled damage plasticity model; Cpt215.