Experimental validation of seismic code provisions for RC columns

The aim of the experimental programme was to check the validity of the provisions of Eurocode 8 regarding the confining reinforcement of columns. 37 full-scale specimens were subjected to large cyclic displacements under constant axial load. Single rectangular hoops, even closely spaced, proved to be inadequate, as in most cases the target ductility was not reached. On the contrary, double or triple arrangement of hoops ensured satisfactory behaviour; they ensured acceptable force response degradation (lower than 20%), when the columns were subject to large displacement reversals (compatible with the target ductility).