Avaliação da substituição da armadura transversal mínima por fibras de aço em vigas de concreto armado (Evaluation of the replacement of minimum shear reinforcement by steel fibers in reinforced concrete beams)

The shear strength of fiber reinforced elements is usually predicted through analytical models calibrated from experimental tests. Few results obtained from these tests consider the mechanical characterization of the material, allowing to evaluate the different performances of fiber reinforced concrete. This work evaluates the possibility of replacing the minimum shear reinforcement of reinforced concrete beams with steel fibers. For this, comparations were made evaluating the shear strength of 240 experimental tests of steel fiber reinforced concrete (SFRC) beams using formulations from the literature and international standards, to define which equations are in better agreement with the experimental data. Thus, once this expression was identified, SFRC beam design abacuses were developed to determine the amount of steel fibers needed to replace the minimum shear reinforcement, according to NBR 6118 [1]. The results showed that the model by Kwak et al. [2] presented results similar to those obtained in experimental tests of beams. Finally, it is concluded that the developed abacuses will facilitate decision-making in the design of SFRC beams.