Effect of Steel Fiber on The Behavior of Deep Beams With and Without Web Opening

Abstract

This study investigates experimentally the strengthening of reinforced concrete deep beams using steel fibers. The experimental work could be divided in two parts, the first part consists of casting and testing six deep beams without web opening and the second part consists of casting and testing six deep beams with web openings to show the effect of volume of steel fibers on the behavior of the deep beams with and without web opening on ultimate load, deflection, with various shear span to depth (a/d) ratios [variable of clear shear span].On the other hand, the effects of these parameters on the behavior and capability of deep beams with constant steel fiber – volume fraction are obtained by using three groups of beams having steel fiber– volume fractions of 0.0%, 0.5%, 1.0% and studying the effect of the presence of steel fibers in deep beams with web openings. The results obtained from the experimental work [solid deep beams and deep beams with web openings], demonstrate that when the steel fiber volume- fraction is increased, the ultimate loads are also increased. The effect of steel fibers increases as the (a/d) ratio is decreased. In addition, the experimental work on deep beams without web opening showed that when the steel fiber volume-fraction is kept constant, the ultimate loads are increased as the (a/d) ratio is decreased. On the other hand, the percentages of increase in ultimate loads become higher as the steel fiber volumefraction is increased from 0.0% to 0.5% and 1.0%. However, the effect of decreasing the (a/d) ratio on the ultimate and cracking loads of the deep beams with web openings was not significant.