Hybrid Reinforcement (Rebars + Fibers) for elevated slabs

When designing Fiber Reinforced Concrete (FRC) structures, one of the basic issues is represented by the choice of a proper combination of fibers and conventional reinforcement that allows to obtain the best structural performance with the minimum amount of materials. The combination of rebars and fibers in the concrete matrix is generally known as Hybrid Reinforced Concrete (HRC). HRC represents a feasible solution in many structures; among these, slabs are gaining an increasing interest among practitioners. In fact, slabs are the most widespread structural elements in common practice since they are typically used to construct industrial floors (slab on grade), foundations (slab on piles) or floors (elevated slabs). This paper focuses on the design of FRC elevated slabs by using the most recent design provisions reported in the fib Model Code 2010. Emphasis will be given at the use of HRC for optimizing the slab reinforcement. In more detail, the results of a parametric study performed to design the Hybrid Reinforcement for elevated slabs will be presented and discussed and a procedure for designing the Hybrid Reinforcement will be proposed and verified by nonlinear finite element analyses.