Similarities between punching and shear strength of steel fiber reinforced concrete (SFRC) slabs and beams

Resumo

This paper discusses the influence of steel fiber in both punching strength of flat slabs and shear strength of concrete beams. Similarities in the structural behavior were observed in an experimental analysis of analogous slabs and beams. The analogous slabs and beams had the same height, longitudinal reinforcement ratio and concrete properties. Concrete mixtures were designed to attain different strength levels, from ordinary to high-strength range. Hooked-end steel fibers with circular section and rectangular section and different aspect ratios were used. Ultimate load capacity and ductility of analogous slabs and beams showed the same performance tendencies as the fiber content varied from 0% to 2%. Analytical investigations were developed to evaluate the ultimate load capacity of slabs and beams. The main conclusions are: a) shear tests on prismatic beams provide useful information for steel fiber reinforced concrete (SFRC) mixture design for slab application; b) theoretical strength models that have a linear dependence on fiber content can be used to predict the effect of fiber addition.