Cyclic Performance and Environmental Impact of Precast Demountable RCS Joints

To facilitate the disassembly and recycling of structural components, this study proposes a novel demountable reinforced-concrete column–steel beam (RCS) joint. Numerical simulations were conducted to analyze the performance of this new RCS joint using finite element software ABAQUS 2021. Simultaneously, to expand the parametric analysis of the finite element model, further validating aspects such as concrete strength, the flange strength of the steel beam, the strength of the gusset plates, and the longitudinal reinforcement ratio were studied. The finite element analysis results demonstrate that the proposed demountable RCS joint exhibits superior bearing capacity and ductility compared to conventional cast-in-place joints. To further investigate the seismic behavior and influencing rules of this joint, analyses were carried out focusing on aspects such as hysteresis curves, skeleton curves, ductility, energy dissipation, residual deformations, and strength degradation. The findings reveal that gusset plate strengths, steel beam strength, beam-end connecting plate strength, longitudinal reinforcement ratio, and concrete strength have significant impacts on the strength and failure modes of the RCS joints. In addition, the life cycle analysis of four different material structures shows that the demountable RCS joints have the smallest carbon emission during the life cycle, which is conducive to the reuse of resources. Finally, the development of demountable RCS joints is proposed for China’s construction industry.