INFLUENCE OF STEEL FIBRE REINFORCEMENT ON THE FRACTURE BEHAVIOUR OF CONCRETE IN COMPRESSION.

Experimental results are presented to describe the compressive load-deformation characteristics of steel fiber reinforced concrete. The influence of steel fiber reinforcement on the fracture process of concrete is discussed, based on data for various volumes of melt extract, hooked, straight and crimped steel fibers. The results indicate that the primary effect of steel fiber reinforcement on the fracture behavior of concrete up to ultimate stress is very similar to the characteristics imparted by coarse aggregate inclusions. The initiation and critical stress and strain values decrease with increasing fiber content and the volume of the crack phase in the matrix increases. Steel fiber reinforcement improves the energy absorption capacity of concrete due to the higher lateral strain capacity imparted by steel fibers and due to energy dissipation during pull-out of fibers which bridge tension and shear cracks in the failing matrix.