Effects of Different Types of Steel Fibers on the Mechanical Properties of High Strength Concrete

This paper is aimed at comparison of different types of steel fibres in relation to their influence on the final mechanical properties of High Strength Concrete (HSC). The most affected characteristics of concrete were fracture energy, flexural and split strength, which are the main goals of using fibre reinforcement, as HSC has otherwise low ductility that can result in sudden failure of the concrete structural element. Expected better behaviour of high-strength steel fibres hooked at the ends than of the ones of normal strength with only flattened ends was approved. The highest values of fracture energy was achieved with the longest steel fibres - 60 mm (diameter 0.75 mm). Whereas shorter fibres (30 mm) of the same diameter reached increased flexural and split strength.