SHEAR BEHAVIOR OF FIBER-REINFORCED CONCRETE BEAMS: AN EXPERIMENTAL STUDY

Abstract

Eight steel fiber-reinforced normal strength concrete beams (200 mm wide, 250 mm deep and 1500 mm long) were tested in bending under two concentrated loads, without and with stirrups. The concrete beams were designed to have marked shear behavior. Three types of steel fibers (SFs), straight, hooked and corrugated, were investigated as a possible replacement for standard transverse reinforcement. The fiber volume content, the aspect ratio of fibers, and the existence of stirrups were the major testing parameters in this regard. Four fiber volume proportions (Rf of 0%, 0.5%, 1.0% and 1.5%) and three aspect ratios (l/d of 50, 55 and 60) were utilized. According to the experimental data, the shear behavior of steel fiber-reinforced normal strength concrete beams (SFRCBs) without stirrups was similar, if not superior, to that of normal strength concrete beams (RCBs) with stirrup reinforcement. The SFRCBs displayed extremely thin diagonal cracks and higher shear strengths, especially for fiber fractions of 1% and 1.5%. The experimental results were compared to major universal codes and existing models from the literature. The major codes undervalue the concrete contribution to shear strength while exaggerating the contribution of the stirrups. Furthermore, some of the existing models overestimate the fibers’ contribution to the shear strength, while others underestimate it when compared to the present experimental findings.