Experimental study on steel reinforced concrete T-section beam subjected to pure torsion and combined action of bending-torsion

This paper presents the mechanical behavior of T-section steel reinforced concrete (TSRC) beam under pure torsion and bending torsion. 12 TSRC beams, varying in flange aspect ratio, steel ratio, volume stirrup ratio, flange longitudinal reinforcement diameter and torsion-bending ratio, were tested. The test results indicated that the reinforced concrete beam presents brittle failure, and the steel reinforced concrete beam presents ductile failure. There is a mutual constraint between the flange, steel and concrete of the specimen, and the flange and steel significantly enhance the torsional strength and ductility of the specimen. The optimum aspect ratio of specimen flange is 2.33; with the increase of steel content, the torsional strength and ductility of the specimens increased, with an average increase of 30.99 % and 73.58 %, respectively. The ultimate torque of the specimen increases with the increase of the bending-torsion ratio, with an average increase of 7.86 %. Finally, the calculation method of cracking torque and ultimate torque of T-section steel reinforced concrete beam is proposed, and the calculated results are in good agreement with the experimental results.