Numerical Simulations of RACFST Columns Under Concentric Axial Load

Recycled aggregate concrete (RAC) is both economical in construction and eco-friendly in waste disposal. Nowadays recycled aggregate concrete-filled steel tubular (RACFST) column is getting popularity. The design requirements for the RACFST column have a lot of room for improvement, given its recent innovation. Numerical simulations of RACFST columns under concentric axial load are presented in this work. The ABAQUS software is utilized to generate a 3D finite element (FE) model. The developed model incorporates both geometric and material nonlinearity. A concrete damage plasticity model is used to track the nonlinear behavior of concrete. The FE model is validated using experimental results available in the literature. The model is found to be capable of successfully tracing the load–deformation behavior and failure mode observed in the reference tests. Comparisons are made among the specimens with variable parameters including RAC ratio, steel percentage, and slenderness of the steel tube. The results predicted by the model are similar to the test results. Steel percentage and RAC replacement ratio show the most and the least significant influence on the load-carrying capacity, respectively. In addition, the individual contributions of steel and concrete are determined.