In order to simplify the calculation of the ultimate bending capacity of rectangular, solid, or hollow, reinforced concrete beams subjected to bending and torsion the authors introduce approximate expressions connecting the angle of crack in the vertical face with the ratio of the bending moment to the torsion moment. Using these expressions design equations are derived and it is shown that the results obtained using these equations are in close agreement with experimental results.
D.R. Fairbairn and S.R. Davies