REINFORCED-CONCRETE BEAMS WITH STEEL FIBERS UNDER SHEAR

The effect of steel fibers on the behavior and strength of reinforced concrete beams under shear is studied. Nine fiber reinforced beams and one plain reinforced concrete beam were tested by two-point loading. The fiber content ranged from 0.4 to 1 percent, and the aspect ratio of the fibers was between 60 and 120. Improvement of first-crack load and ultimate load over that of plain concrete was noted. The first-crack strength ratio of fibrous and plain beams was a function of fiber spacing. The ultimate strength of fibrous beams under shear was much higher than that of the plain concrete beam, depending on the energy absorbed in debonding and stretching the fibers, which is directly proportional to the fiber volume content and aspect ratio.