Rinforzo di nodi trave-pilastro d’angolo con incamiciatura in calcestruzzo fibro-rinforzato ad elevate prestazioni

The experimental results on full-scale corner beam-column joints tests are presented herein, with the aim of studying the effectiveness in strengthening existing RC structures of a retrofitting technique based on the application of a HPFRC jacket. The specimens subassemblies were designed only for gravity loads and with structural deficiencies typical of the Italian construction practice of the 60’s-70’s: absence of any capacity design principle, use of smooth bars, inadequate reinforcement detailing, such as total lack of stirrups in the joint panel and hooked-end anchorages. Both unretrofitted and retrofitted specimens were subjected first to the serviceability loads combination and then to simulated seismic loads up to failure. The results underline the significant vulnerability of the joint panel region and the critical role of the slip phenomena related to the use of smooth bars and show that, with the application of a HPFRC jacket, it is possible to increase the bearing capacity of the columns, reaching also an adequate level of ductility and strength of the beam column joints.