Abstract: “In this study, behaviour of reinforced concrete beams under pure torsion have been investigated. Test series comprise of 12 units of reinforced concrete beams of 250x300x1500 mm. Stirrup spacing was selected 80 mm and 100 mm, concrete class was selected C20 and C40. The test specimens divided into 4 groups. In the test specimens, 16 mm was used for the longitudinal reinforcement, 8 mm was used for the stirrup and convensional concrete was used. The torsioal moment capacity, rotation angles of the concrete beams was investigated. In addition to this, the releationship between the torsional moment and rotation angles, the failure torsional moment, the cracks occuring at the beams were examined. For the theorically formula of torsional moment capacity, American Concrete Institute (ACI), Eurocode-2, Turkish Standart, elastic, plastic and skew-bending theories were used. Experimental results and theoretical results of the torsional moment capacity and the failure torsional moment were compa”

Keywords: torsion, unit rotation angle, elastic theory, plastic theory, skew-bending theory