Corner beam-column joints retrofitting with HPFRC jacketing

The effectiveness of a new retrofitting technique, based on the application of High Performance Fiber Reinforced Concrete jacketing for seismic upgrade of RC corner beam-column joints is investigated herein. Three full-scale experimental tests on beam-column corner joint specimens subjected to seismic loads have been performed. The specimens have been designed according to the Italian construction practice of the 60’s-70’s with typical structural deficiencies, such as use of smooth bars with hooked-end anchorage and lack of stirrups in the joint panel. The tests, performed on the unretrofitted specimens, underline the high vulnerability of the joint panel zone and the critical role of smooth reinforcement bond-slip effect. Moreover, the test showed that the retrofitting proposed solution allows increasing the bearing capacity of columns and the strength of beam-column joints, whit very little visible damage, reaching also an adequate level of ductility.