Effect of loading rates on shear behavior of reinforced concrete beams with hybrid steel fibres

Although experimental and numerical studies have been carried out for years on shear behavior of RC structures, it is one of the difficult and complex issues, which is not yet fully understood. Shear failure, in which many parameters are effective, is very dangerous as it is sudden and brittle. It is well known that concrete strength, the shear– span/depth ratio (av/d) and the amount of longitudinal tensile reinforcement are important parameters affecting the collapse behavior of beams without shear reinforcement. In recent studies, it has been found that steel fibre concrete and loading rate also affect the shear behavior of RC beams, but the results regarding the loading rate are controversial. In this study, the failure behavior of fiberless, macro steel fiber and hybrid steel fiber RC beams with longitudinal tensile reinforcement and no shear reinforcement, with an av/d ratio of 2.38, under 1.6 mm/min and 40 mm/min loading rates were investigated. It has been found that the use of steel fiber and loading rate parameters significantly change the shear failure behavior of RC beams. By recording load values and crack formation stages simultaneously, very important data regarding the shear behavior of RC beams was obtained.