Load-Carrying Capacity of SFRC Suspended Slabs with Different Support Conditions

Abstract

Traditionally, steel fibres have been used in ground- and pilesupported concrete slabs. More recently, the structural use of steel fibres in suspended concrete slabs is on the rise. In the present research study, the structural behaviour of suspended steel-fibre-reinforced concrete (SFRC) slabs was investigated by means of non-linear finite-element analysis (NLFEA). The numerical models were calibrated (at the material level) and validated (at the structural level) using existing experimental data. NLFEA-based parametric studies were carried out to extend the range of Vf beyond the one considered in the experiential investigations. The aim was to determine the correlation between the slab load-carrying capacity and the corresponding fibre dosage increase. This is useful for design purposes and can provide guidance on the amount of fibres needed to achieve a certain prescribed load resistance level. It was found that the addition of steel fibres improved the load-carrying capacity and changed the failure mode to a flexural ductile one. Other critical structural performance indicators were also examined such as deflections, ductility, energy absorption and cracking patterns. So, in essence both the ultimate and serviceability limit states were investigated. Comparisons with current design guidelines were also made and recommendations for improvements proposed.