STRUCTURAL APPLICATION OF STEEL FIBRE AS ONLY REINFORCING IN FREE SUSPENDED ELEVATED SLABS: CONDITIONS - DESIGN - EXAMPLES

摘要

Total replacement of traditional rebars is now completely routine in applications like suspended slabs resting on a pilegrid spanning from 3 m to 5 m each way with a span to depth ratio ranging from 12 to 25 in general. Significant costs savings in time and materials are achieved, completely omitting all other traditional reinforcing. More recently the structural use of steelfibres as only reinforcing has been investigated in the case of suspended slabs with a span to depth ratio ranging from 20 to 40, and spans typically ranging from 5 m to 8 m. The present article reviews the conditions to be met by the SFRC material and the way to achieve these conditions from theory down to installation on the jobsite: 1. a careful and comprehensive method of mix designing to ensure that SFR concrete is pumpable and compactable. 2. a detailed method of design derived from slab testing to rupture where theories, elastic and plastic, have been verified and improved. 3. real cases of such slabs, analysed at design stage and during construction.