CONNECTIONS FOR PRECAST FLOOR SLABS
Floor slab connection essentially consists of a compression joint in the bearing surface. The bearing length should be atleast 75mm to avoid spalling of the edges.
To prevent this short of failure occurring, the slab must be tied to the beam.
Connections in Hollow Core Slab:
The problem with hollow core slabs is that there is no projecting reinforcement in the slab, so a frictional tie is required. The tops of some of the cores are removed and are made ready to receive the site bars which are projecting form the beam. Finally the gap at the ends of the slab and the beam is filed so that there is a positive tie between the two components.
Connections in Double Tee Slabs:
The tie force in the double tee slabs is provided in the temporary situation by welding two plates together. This tie prevents the beam and the slab separating during the in-situ concrete screeding operation.
First, a rubber bearing is placed at the support point. When the slab is in position, a welded connection is made. Reinforcement is placed onto the top of the slab. This should lap with the projecting bars. Finally, in-situ concrete is poured.