Experimental Investigation on a Hybrid Jointed Precast Frame with Non-tearing Floor Connections
The effects of beam elongation in precast frame systems have demonstrated a potential source of un-expected damage to precast floor systems, unless adequate detailing is provided to account for displacement incompatibilities between the lateral resisting systems and the floor.
The Precast Concrete Seismic Structural Systems (PRESSS) research program has shown the efficiency of dry-jointed ductile connections for moment resisting frames in order to reduce damage while sustaining high lateral loads. However, damage to precast floor systems, resulting from a geometric elongation of the beam, has yet to be addressed in detail.
In this contribution an overview of alternative solutions developed for post-tensioned “hybrid” connections is first provided. A series of quasi-static cyclic tests on a major 2-D, 2/3 scale, two story, single bay, precast concrete frame system with an innovative “non-tearing floor” connection is presented. The proposed solution consists of an efficient floor to lateral load resisting connection system which can mitigate the effects of geometric (and material) beam elongation. The response of the “non-tearing floor” solution is compared to alternative more traditional solutions.
Both numerical and experimental results confirm the unique flexibility of the proposed solution and highlight the superior performance under seismic loading sustaining only minor damage to the frame, wall and floor systems under major earthquake events