EXPERIMENTAL BEHAVIOUR OF SEMI-DRY COLUMN-FOUNDATION CONNECTIONS FOR PRECAST BUILDINGS

Column-to-foundation connections are experimentally investigated in this research project, as there is an increasing interest for using innovative connections in precast concrete structures. The focus is on their behaviour under horizontal cyclic loads, that is of primary importance in case of seismic actions.
This project was developed within the framework of a comprehensive European research programme called SAFECAST. The tests were carried out to compare different connection systems: bars inserted in the foundation and innovative semi-dry mechanical connections.
In all specimens and for all connection types, the column and the foundation had the same geometry (column cross-section 40 x 40 cm; column height 2.50 m), and also the loading procedure - with increasing load intensity – was the same.
The columns were tested under a constant axial compressive force (380 kN). The aim of the tests was to measure the ultimate capacity of each connection under cyclic horizontal loads, as well as to assess the ductility, the energy dissipation capability and the extension of the plastic hinge forming at the foot of the column. A numerical investigation was carried out as well, to give designers simple calculation tools based on the fitting of first-hand test results.