Experimental investigations of the H-shaped post-tensioned precast frame module with monolithic beam-column connections

In this study, the evolution of the frame in a structural behavior’s perspective is focused, identifying how cracks influence the degradations of the frame from the camber cracks to plastic hinges. An extensive experimental investigation for the H-shaped post-tensioned precast frame module with monolithic beam-column connections using bolted plate connections is performed to identify the ductile behavior of the H-shaped post-tensioned precast frame module. The inelastic stresses are observed to be redistributed until the failure mechanism with the three plastic hinges are formed in the prestressed beam, which dissipates an inelastic energy in a ductile fashion. No noticeable deformation in plates and bolts for both the first and second floor of the precast frame is found at the final stroke when the experiment was terminated, elucidating that bolted plate connections provide the frame with connections similar to the concrete monolithic joints. Structural behaviors are also investigated using nonlinear finite element analyses based on a damaged concrete plasticity model, unraveling the principles governing crack formations within tested frames. This investigatory approach yields valuable insights for designing post-tensioned precast frames with mechanical column joints. The proposed frame is verified as an option for modular off-site construction to replace cast-in-concrete monolithic frames.