Cold weather concreting – composite slabs on steel decking
Composite slabs on steel decking are widely used in steel framed buildings as they provide a quick and economical form of construction. However, care should be taken when the slabs are cast during cold weather; steel decking is a poor insulator and composite slabs are often cast with little protection to the elements. Thus there is a risk that the concrete could freeze at the steel interface, thereby compromising the composite action required for structural capacity. Precautions to prevent the concrete at the steel interface falling below 5oC should be made until the concrete has achieved at least 5N/mm2, e.g. heaters in enclosures on the floor area under the slab being cast.
Guidance on other aspects of the construction of composite slabs is given in Concrete Society Good Concrete Guide 5, Composite concrete slabs on steel decking.