Effect of Longitudinal Rebars on Torsional Strength in Concrete Beams

In this paper, test and evaluation of torsional strength of concrete beams reinforced with longitudinal rebars and without transverse reinforcement, is considered. Most of concrete codes dose not consider any post cracking torsional strength for concrete element which are not reinforced with torsional reinforcement. It seems that ordinary concrete elements, reinforced for bending, have a post cracking torsion strength (TC), due to aggregate interlock and dowel action. According to the test results, beams which were reinforced by a moderate ratios of longitudinal rebars, showed a ductile torsional behavior in relatively high torsional rotations. A post cracking strength about 50 percent of (Tcr) is suggested for these beams.