Slim floor beams

In the UK there are two main slim floor options. The first, known as SLIMFLOR^®, shown below, comprises a column section with a plate welded to the bottom flange to support deep steel decking, or in some circumstances pre-cast concrete slabs. 

 

Almost the whole section is protected from the fire by the floor slab and periods of fire resistance up to 60 minutes are achievable without protection to the exposed bottom plate.

 

 

 

The second option also used deep decking but removes the support plate by using an asymmetric beam, shown below.  This eliminates welding but retains the easy assembly and the 60 minute fire resistance properties of the original design.  This system has been patented by Tata Steel under the trade name SLIMDEK^®.

The shape of the asymmetric beam is uniquely designed to give optimum performance in fire. A thick web/thin flange configuration gives maximum capacity under the non-uniform temperature distribution at the fire limit state.  Slimdek can also be used with precast planks and design guidance will be available from mid 2006.