Experimental Investigations On High-Performance Jointed Ductile Connections For Precast Frame Systems

Abstract

Recent developments on high performance seismic resisting precast concrete frame systems, based on the use of unbonded post-tensioned tendons with self-centring capabilities in combination, when required, with additional sources of energy dissipation, are herein presented. Alternative arrangements for jointed ductile connections to accommodate different structural or architectural needs have been implemented and validated through quasi-static cyclic tests on a series of exterior beam-column subassemblies under uni- or bi-directional loading regime. The results confirmed the unique flexibility and efficiency of these systems for the development of the next generation of seismic resisting structures, able to undergo high inelastic displacement with limited level of damage and negligible residual displacement when compared to traditional monolithic (cast-insitu) ductile solutions. In order to further emphasize the enhanced performance of these systems, a comparison with the experimental response and observed damage of 2-D and 3-D monolithic beam-column benchmark specimens designed according to the NZ3101:1995 seismic code provisions is carried out. The reliability and simplicity of recently implemented special code provisions for the design and analysis of jointed ductile systems is also confirmed by satisfactory results of analyticalexperimental comparison. In addition, the practical feasibility and efficiency of simple technical solutions to connect precast floor systems and lateral resisting frame systems, without incurring in damage due to displacement incompatibilities are experimentally demonstrated. The reliability of recently implemented special code provisions for the design and analysis of jointed ductile hybrid systems is also confirmed.