Design methodology and seismic performance testing of prefabricated RCS hybrid frame considering composite effects of slabs

Abstract

Reinforced concrete column–steel beam (RCS) hybrid frames are an innovative structural system that integrates steel beams and reinforced concrete columns, thereby offering an efficient structural system for modern buildings. However, the influence of the composite effect of the slab on the seismic behaviour has not been fully investigated in current designs. This study introduces a novel prefabricated RCS hybrid frame that explicitly considers slab composite effects and evaluates its seismic performance. A ½–scale one–bay two–storey precast composite column–steel hybrid frame is designed and tested under cyclic loading. The crack propagation, damage progression, failure modes, hysteresis performance, load–bearing capacity, stiffness, deformation, and energy dissipation, among other seismic performance metrics, are analysed. Experimental results indicate that the hybrid frame remains elastic under an overall drift ratio of 0.25 % and achieves an ultimate overall drift ratio of 3.76 %. Additionally, the panel zone remains in an elastic state during loading, with the structure demonstrating favourable plastic deformation and energy dissipation. Results of finite–element analysis indicate that considering the slab composite effects resulted in a 74 % increase in the lateral stiffness and a 44 % increase in the maximum load–bearing capacity. These findings validate the favourable seismic performance of the proposed RCS hybrid frame system and provide valuable scientific and technical insights for optimising such structural designs.