PRESTRESSED FIBER REINFORCED-CONCRETE BEAMS SUBJECTED TO TORSION

Reports test results of 18 rectangular axially prestressed and nonprestressed concrete beams with and without fiber reinforcement subjected to torsion. The major parameters of the study were the volume fraction of steel fibers and the prestressing level. The experimental results show that there is no increase in torsional strength up to 1.0 percent fiber volume content. Beyond this the torsional strength however increases with the increasing fiber content but the increase in strength practically levels off again between 1.5 to 2.0 percent fiber content. A variable reduction factor was established and incorporated in the existing skew-bending equations to estimate the torsional strength of prestressed concrete beams containing steel fibers. The modified equations were verified by using the experimental results of other researchers and proved to be satisfactory for similar fibers.