Performance of dry prestressed beam-to-column joints for precast concrete frame under vertical seismic loads

Performance of novel dry prestressed beam-to-column joints in precast concrete frames under vertical loads was investigated by experimental and numerical study. Two single-story and two-span precast concrete frames were tested under ortho symmetric or antisymmetric vertical low cyclic reversed loading on beams. The dry prestressed joints had better load capacities and energy dissipation in the frame under symmetric load, while both frames failed in ductile mode. Then a finite element model was developed based on experiments, by which parametric analysis was done including the tension control stress of prestressed tendons on beam ends and the axial compression ratio on columns. The numerical results revealed that the joint exhibited good mechanical performance with the increased tensile control stress of tendons and axial compression ratio of columns. More rigid behavior of joints appeared with increased tensile control stress, and higher load capacity increased with axial force on columns. These findings provide good evidence for designing dry prestressed joints in precast concrete frame.