Shear Behavior of Reinforced Concrete Beams Containing Wavy Steel Fibers

One of the most dangerous kinds of the damage in concrete structural members is shear failure with a sudden and brittle failure. Hence, according to numerous codes of practice, using sufficient transverse reinforcement in the critical region is necessary. For this reason, to improve the shear behavior and change the brittle behavior to ductile one, steel fiber can play an important role. In this research, the effect of short wavy steel fiber in the shear behavior of reinforced concrete beams with normal strength was investigated. The experiments were conducted in three groups. in the first group, concrete containing steel fiber without stirrup (BF), in second group, concrete containing stirrup without steel fiber (BS) and in the third group, concrete containing steel fiber with stirrup (BFS) have been placed. The results indicated that by replacement of the fiber with the same volume instead of stirrup higher stiffness and ductility can be reached without the reduction in strength. Also, increasing steel fiber, the shear failure will be changed into bending failure indicating rapid growth of the shear strength in comparison with bending strength. Distances and the length of cracks in the beams containing steel fiber were shorter. These cracks were created discontinuously and after continuing the loading, were connected to each other. Moreover, these cracks were along with a lower voice in comparison with beams without fiber during the loading, indicating the more uniform redistribution of stresses. Finally, can be said, for the prevention of the sudden cracks and the better redistribution of stresses, the increase of the amount of the steel fiber is more effective than the increase of the amount of stirrup.