Structural Design

The Slimdek system using Asymmetric Slimflor Beams (ASBs) is designed for two load situations, firstly during construction, when the concrete has been placed but the restraining effect caused by solidification of the concrete is not present and secondly, the normal situation, when the slab is cast and the floor is subject to not only the self-weight of the concrete but the imposed loads resulting from use.

The slab, comprising concrete poured onto profiled metal decking, is considered to be composite but the beams between which the slab spans may be either composite or non-composite in the completed structure. Composite beams should be designed in accordance with BS 5950–3.1 and may be designed plastically whereas non-composite beams are designed using BS 5950–1.

In the construction stage, the top flange of the beam is laterally unrestrained and lateral torsional buckling could prove to be the governing condition if the construction sequence requires the floor to be cast on one side of a beam but not on the other.

The members provide temporary stability and robustness in line with the requirements of the Building Regulations and BS 5950–1:2000.

Slimdek is backed up by full-scale tests which were carried out to verify the structural performance of the Slimdek components and of the system in fire.

Deck span and beam selector tables and the SIDS design software are available to simplify the design process.

Worked example.