Steel fiber concrete slabs on grade: a structural matter

An extensive experimental investigation with the aim of studying the structural behavior of slabs on ground made of steel fiber- reinforced concrete (SFRC) is presented in this paper. Several full- scale slabs reinforced with different volume fractions of steel fibers having different geometries were tested under a point load in the slab center. A hybrid combination of short and long fibers was also considered to optimize structural behavior. Experimental results show that steel fibers significantly enhance the bearing capacity and the ductility of slabs on ground. The nonlinear behavior of these SFRC structures is well captured by performing nonlinear fracture mechanics analyses where the constitutive relations of cracked concrete under tension were experimentally determined. Finally, from an extensive parametric study, design abaci and a simplified analytical equation for predicting the minimum thickness of SFRC slabs on ground are proposed