Fiber Reinforced Concrete Beams Subjected to Combined Bending and Torsion
Gordon Batson, Terry Terry, and Ming-Sung Chang
Appears on pages(s):
beams (supports); bending; fiber reinforced concretes;loads (forces); metal fibers; torsion.
Test data using steel fibers as torsional shear reinforcement for 36 reinforced concrete beams subjected to combined bending and torsion are presented. Beams were loaded in bending at third points and by third point torsional loading. Straight steel fibers were 1.0 in (25.4 mm) long by 0.010 x 0.022 in (2.5 x 5.0 mm) in cross section and the volume percentages of fibers were 0.0, 0.5 and 1.0 and 1.5 percent. Test data were compared to a theory developed by Martin for concrete beams subjected to bending and torsion reinforced with longitudinal steel only, no closed stirrups. One volume percent or greater of straight steel fibers in combination with longitudinal torsional reinforcement were effective as torsional reinforcement for M/T ratios less than two. For M/T ratios greater than 10, 0.5 volume per cent was sufficient for torsional rein-forcement.