Analytical Investigation on Catenary Action in Unbonded Prestressed Concrete Beam-Column Subassemblages

One reinforced concrete (RC) and four prestressed concrete (PC) beam-column subassemblages with various tendon profiles were designed and tested to investigate the effect of prestressed tendon profiles on the progressive collapse response of PC frames. An analytical model was developed to evaluate the PC frames’ catenary action (CA) response by identifying the fracture of longitudinal reinforcement and prestressed tendons in beams. The effect of the bond mechanism on the rupture strain of reinforcement was considered. Then, the proposed model was validated using experimental and simulation results. Finally, parametric studies were performed based on the calibrated model. Test results indicate that the prestressed tendon profile significantly impacts the CA response of PC frames against progressive collapse. The analytical model can effectively reflect the effect of the prestressed tendons on the CA resistance and displacement of PC frames.