Role of the tensile constitutive modeling on the structural response of fiber reinforced concrete flat slabs: A numerical study

For decades, fiber reinforced concrete (FRC) has been primarily used in elements for which the consequences of potential failure are minor, like slabs on grade and precast tunnel segments, just to name a few examples. With reference to slabs supported on walls and/or columns, the use of fibers as partial or main reinforcement has increased over the last 15 years. Despite the existence of advanced design codes like the fib Model Code 2010, experimental data, and standing buildings that prove the technical feasibility of FRC, there are still barriers for its use at a wider scale. Technical aspects such as the uncertainties in the identification procedure of FRC uniaxial tensile laws and the influence of the FRC post-cracking strength class on the serviceability and ultimate limit states response are among the factors that prevent a larger diffusion of FRC. In this paper, the role played by several tensile post-cracking constitutive models—among those most commonly used both in research and in design practice—on the structural response of FRC flat slabs is investigated. The effect of numerical modeling choices such as (i) the influence of shell or brick elements and (ii) the influence of material homogeneity or heterogeneity along the slab thickness on the structural response of FRC flat slabs is also examined.