Seismic retrofit of reinforced concrete buildings using low-damage external exoskeletons

Recent earthquakes have further highlighted the high vulnerability of RC buildings built prior to the 1970’s. This work focuses on global retrofit interventions with external exoskeletons using low-damage PRESSS (PREcast Seismic Structural System) Technologies, based on unbonded post-tensioned jointed ductile connections and relying on a peculiar rocking and dissipating mechanism. Following a Displacement-Based Retrofit procedure, the feasibility and efficiency of implementing a PRESSS exoskeleton frame, able to protect the existing building by targeting a specific performance level, is investigated. Non-linear static and dynamic analyses are carried out to validate the design procedure and verify the overall performance of the retrofitted building.