Cyclic behaviour of a column to foundation joint for concrete precast structures

This paper aims at presenting the results of two experimental tests concerning the cyclic behaviour of a dissipative column-to-foundation connection for precast concrete elements. The tested joints are characterized by the use of high strength threaded steel bars partially un-bonded in grouted sleeves and by steel support elements which allow an easy assemblage and centering of the column. The two specimens differ in bar number and bar diameter of the un-bonded high-strength bars adopted to restore the flexural continuity. The experimental results are compared to the response of a pocket foundation joint and they show a good performance of the joint in term of resistance, ductility, cycle stability and energy dissipation. The specimen damage is localized at the column base thus allowing a simple retrofitting after a seismic event