Effect of steel fiber hybridization on the fracture behavior of self-consolidating concretes

In the present work the effect of steel fiber hybridization on the mechanical and rheological behavior of self-consolidating concretes was studied. Straight and hooked end steel fibers with different lengths and diameters were used as reinforcement in fiber volume fractions of 1.0% and 1.5%. The viscosity and shear yield stress of the concretes was determined using a parallel plate rheometer. The mechanical behavior was determined by means of compression, tension and bending tests. The movement of the neutral axis under bending load was experimentally determined by strain-gages attached to compression and tensile surfaces. The mechanical response of the material under bi-axial bending was addressed using the round panel test in three different boundary conditions. The obtained results indicated that the fiber hybridization improved the behavior of the composites for low strain and displacement levels increasing the serviceability limit state of the same through the control of the crack width.