Design of profiled steel sheeting as permanent formwork

This technical note reviews the design of profiled sheeting in bending as permanent formwork in composite slabs. The properties of the profiles commonly used in composite construction were evaluated by a series of tests on single-span and double-span sheeting. The tests show that, for the double-span, strengths considerably higher than the elastic design limit specified by codes of practice can be achieved. A method of design for continuous sheeting is proposed, based on a partial-plastic redistribution of moment from the support region to mid span. This offers significant economy by increasing permissible spans, while maintaining an adequate factor of safety against sheet bending failure during construction.