Criteria for the loading of slabs during construction

Two inequalities are derived to establish the loads Chat may be imposed on slabs at an early age. These loads may arise from the slab self-weight immediately after striking the formwork or, slightly later in the construction cycle, when the slab is supporting construction loads from the slabs above. In deriving the inequalities, it was concluded that the criteria defining acceptable loading were related not to safety but to the possible impairment of serviceability performance. Results obtained during the construction of a seven-storey flat slab structure at BRE Cardington as part of the European Concrete Building Project were used to verify the proposals.