CONCRETE TEE-BEAMS SUBJECTED TO TORSION AND COMBINED BENDING AND TORSION

EIGHT PLAIN AND TWENTY-EIGHT REINFORCED CONCRETE TEE- BEAMS, ALL HAVING THE SAME NOMINAL CROSS-SECTION, WERE SUBJECTED TO PURE TORSION AND COMBINED BENDING AND TORSION. TWO PLAIN, THREE LONGITUDINALLY REINFORCED, AND SEVEN LONGITUDINALLY AND TRANSVERSELY REINFORCED BEAMS WERE SUBJECTED TO PURE TORSION. SIX PLAIN BEAMS AND EIGHTEEN BEAMS REINFORCED WITH LONGITUDINAL AND TRANSVERSE STEEL WERE SUBJECTED TO VARIOUS COMBINATIONS OF TORQUE AND MOMENT. ALL BEAMS WERE LOADED IN SMALL INCREMENTS TO ULTIMATE LOAD. FOR EACH LOAD INCREMENT CORRESPONDING ANGLES OF TWIST, BEAM DEFLECTION, AND REINFORCING STEEL STRAIN READINGS WERE TAKEN. CRACKS WERE NOTED AS THEY DEVELOPED, AND THE FINAL FAILURE SURFACE WAS RECORDED. ON THE BASIS OF THE EXPERIMENTAL RESULTS, METHODS WERE ESTABLISHED TO PREDICT: THE ULTIMATE TORSIONAL CAPACITY OF PLAIN, LONGITUDINALLY REINFORCED, AND LONGTITUDINALLY AND TRANSVERSELY REINFORCED CONCRETE TEE-BEAMS AND THE ULTIMATE LOAD CAPACITY OF FULLY REINFORCED TEE-BEAMS SUBJECTED TO COMBINED BENDING AND TORSION. THE PROPOSED METHODS OF ANALYSIS SHOW SATISFACTORY AGREEMENT WITH THE EXPERIMENTAL RESULTS OF THIS TESTING PROGRAM. /CGRA/