Cyclic response of composite steel-concrete joint with transition part

Steel-reinforced concrete (SRC) columns are widely used in high-rise buildings, yet the seismic performance of beam-to-SRC column connections requires further study. This research introduces a novel connection featuring a steel profile encased within the reinforced concrete beam (Transition Part) near the SRC column joint. Three specimens were tested under cyclic loading at the beam ends and axial loading on the columns: a reinforced concrete (RC) beam-to-column joint, an RC beam-to-SRC column joint, and an RC beam-to-SRC column joint with a transition part. The specimen with the transition part increased load-bearing capacity by 8% and 16.5% compared to the RC beam-to-SRC column and RC beam-to-column specimens, respectively. Additionally, the RC beam-to-SRC column specimen exhibited an 8% higher load-bearing capacity than the RC beam-to-column specimen. The transition part also improved ductility by 4.5% and 12.4% compared to the RC beam-to-SRC column and RC beam-to-column specimens, respectively. These results indicate that incorporating a steel profile within the beam enhances the seismic performance of beam-to-SRC column connections, offering a promising design approach for high-rise buildings.