Elevated steel fibre reinforced concrete slabs and the hybrid alternative: design approach and parametric study at ultimate limit state

Application of Fibre Reinforced Concrete (FRC) in pile supported flat slabs is definitely challenge in term of a structural application of this material. Possible substitution of traditional reinforcement by steel fibres in the concrete mix drew attention of researchers due to clear benefits that could be provided by this technological alternative. This statement has been already proven by existing examples, in which during the construction, the optimization of resources, reduction of execution time and required labor force was highlighted. Nevertheless, considering the knowledge base associated with structural behaviour of FRC, it has been confirmed that hybrid solutions consisting in FRC with a moderate residual flexural tensile strength combined with conventional reinforcement placed in those zones where the higher bending moments are expected can be even more attractive from the technical point of view. Taking into account the abovementioned, the potential application of Hybrid Reinforced Concrete (HRC) for elevated slabs was studied. By modifying the ratio fibre/rebar content for different structural geometries, a parametric study was carried out in order to evaluate various solutions in terms of structural capacity in accordance with the requirements of Ultimate Limit StateThe authors wish to express their gratitude to the Spanish Ministry of Economy and Competitiveness for the financial support in the scope of the project eFIB (reference: RTC-2016-5236-5) which was carried out along with SACYR Ingeniería e Infraestruturas. The first author also thanks the Department of Enterprise and Education of Catalan Government for providing support through the PhD Industrial Fellowship (2018 DI 77) in collaboration with Smart Engineering Ltd.Peer ReviewedPostprint (published version