T-BEAMS SUBJECT TO COMBINED BENDING AND TORSION

THE BEHAVIOR OF PLAIN AND REINFORCED CONCRETE T-BEAMS SUBJECT TO PURE TORSION AND COMBINED BENDING AND TORSION WAS INVESTIGATED. EIGHT PLAIN AND 28 REINFORCED CONCRETE T- BEAMS, ALL HAVING THE SAME NOMIAL CROSS SECTION WERE TESTED. TWO PLAIN, THREE LONGITUDINALLY REINFORCED, AND SEVEN LONGITUDINALLY AND TRANSVERSELY REINFORCED BEAMS WERE SUBJECTED TO PURE TORSION. SIX PLAIN BEAMS AND 18 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 DEFLECTIONS, AND REINFORCING STEEL STRAINS WERE RECORDED. CRACKS WERE NOTED AS THEY DEVELOPED AND THE FINAL FAILURE SURFACE WAS RECORDED. BASED ON THE EXPERIMENTAL RESULTS, METHODS WERE ESTABLISHED TO PREDICT THE ULTIMATE LOAD CAPACITY OF FULLY REINFORCED T-BEAMS SUBJECT TO COMBINED BENDING AND TORSION. THE PROPOSED METHODS OF ANALYSIS SHOW SATISFACTORY AGREEMENT WITH THE EXPERIMENTAL RESULTS OF THIS TESTING PROGRAM. /ACI/