Fire Resistance of Steel Fibre Reinforced Concrete Elevated Suspended Slabs: ISO Fire Tests and Conclusions for Design

Abstract

Since 2004, a number of projects of multi-storey buildings have been completed in various countries where steel fibres are the only reinforcing of the cast in-situ elevated slabs. A number of full-scale tests at cold stage of these steel fibre reinforced concrete slabs have been conducted to show a very considerable safety margin between the most onerous service loading conditions and the ultimate cases at final collapse. The positive influence of steel fibre reinforcing on the material properties of the concrete under fire conditions is already well known and detailed in the literature dating back 25 years. In 2015, the ACI 544-6R 15 document, “Report on Design and Construction of Steel-Fiber Reinforced Concrete Elevated Slabs” outlines in detail the design method of such slabs but mentions also that further research is needed in the Fire Resistance area. The purpose of the paper here is precisely to address the Fire Resistance of S.F.R.C suspended elevated slabs and walls in full scale under service loadings. The paper outlines the setting-up of the tests of a number of elevated slabs and walls, subjected to the real loading conditions, the observations and then to conclude and confirm by the high positive impact on the design as well as the high safety of these slabs and walls.