Seismic performance of precast prestressed concrete frame joints with buckle mechanical connection of reinforcing bars

This study explores the seismic performance of precast prestressed buckle-type mechanical connections in beam–column joints, aiming to overcome the limitations of traditional wet connections. The research seeks to evaluate the mechanical behavior of these innovative connections under low-cycle reversed loading conditions and determine their effectiveness in enhancing structural integrity and seismic resilience. The experimental approach involved testing multiple specimens with varying prestress levels and axial compression ratios, allowing for a detailed assessment of key factors including energy dissipation, load-bearing capacity, and residual displacement. The results demonstrate that the buckle-type connections exhibit superior energy dissipation and self-centering capabilities compared to conventional connections. Notably, higher prestress levels contributed to enhanced crack closure and reduced residual deformation, while increased axial compression improved energy dissipation. However, prestress relaxation during cyclic loading impacted crack closure in later stages. The study also found that the buckle-type connections can support higher loads, with peak improvements of up to 12.2% when compared with control specimens. The ductility coefficients of the specimens exceeded the standard threshold for reinforced concrete frame joints, further affirming their robustness. The proposed connection design adheres to the “strong column–weak beam” principle, effectively managing plastic hinge formation at the beam ends. This research provides valuable insights into how optimal prestress and axial compression combinations can enhance both the immediate performance and long-term durability of prefabricated seismic connections. The findings contribute to the advancement of prefabricated construction technologies, offering significant improvements in both seismic resilience and sustainability.