Torsion in Concrete Beams Containing an Opening

Abstract

An analysis is presented for predicting the strength of reinforced concrete beams that are subjected to torsion and have openings cast in them in order to provide for the passage of service ducts. The equations proposed are based on addition of stresses due to torsion and flexure in the longitudinal reinforcement and the addition of stresses due to torsion and transverse shear in the stirrups. Test results of 14 beams with openings are also presented. Correlation between the test results and the strength predicted by the analysis indicates that the equations conservatively but adequately predict the strength of the beams.