INNOVATIVE STEEL FIBERS AND THEIR EFFECT ON FIBER DISTRIBUTION IN BEAMS – EXPERIMENTAL INVESTIGATIONS

The post cracking tensile behaviour of fiber reinforced concrete (FRC) scatters with about 20–25% as generally known. The large scattering influences the characteristic material properties as well as the safety factor negatively. As a result, fiber reinforced concrete is mainly used in components with high rearrangement capacity and relatively low load, such as floor slabs or tunnel shells. Investigations by [4, 5, 6] have shown that the large scattering in the post cracking tensile strength occurs in normal strength concrete and ultra high performance concrete, independent of fresh concrete properties. In [7, 8, 9] and [10], the fiber distribution and the fiber orientation are mentioned as reason for the large scattering. Especially the fiber orientation has been focused in the last years, as can be seen in [9, 10 and 11]. Different methods for positive influencing the of fiber orientation have been tested by [12, 13]. However these methods have proved to be INNOVATIVE STEEL FIBERS AND THEIR EFFECT ON FIBER DISTRIBUTION IN BEAMS – EXPERIMENTAL INVESTIGATIONS