Resiliency of Post Tensioned Concrete Frames During Progressive Collapse

Abstract

Progressive collapse occurs when a load bearing section of a structural frame fails and as a result much more of the structure is damaged. Progressive collapse can have catastrophic results, some well-known examples are the Ronan Point Apartment, Alfred P. Murrah building, and the World Trade Center Towers. Precast hybrid moment frames could be a potential solution to how devastating progressive collapse is. Precast hybrid moment frames are being used in seismic regions due to being at least as effective as traditional cast in place concrete but are significantly cheaper when it comes to post earthquake repair costs and remediation. Despite how frequently they are being used in seismic regions, there has not been much research on how they perform in progressive collapse. Precast hybrid moment frames during a progressive collapse event could be safer and cheaper when it comes to repairs.A half scale post tensioned frame with similar attributes to a precast hybrid moment frame was tested and compared to a half scale standard reinforced frame in order to investigate how the frames compared during a progressive collapse event. The frames were subjected to iterative displacements applied by an actuator. Data was collected using LVDTs, load cells, and visual observations. It was found that post tensioned frames could be more resistant to damage than standard reinforced frames. The research indicated that the frame’s ability to resist damage could help with public safety following a progressive collapse event.