Lateral Torsional Buckling of Rectangular Reinforced Concrete Beams

This paper reports the results of a study aimed at investigating the lateral stability of rectangular reinforced concrete slender beams. A total of nine reinforced concrete beams of rectangular cross-section with d/b ratios ranging from 10.20 to 12.45 and Lb ratios varying between 96 and 156 were tested. A gravity load simulator that allowed the load to remain vertical when the beam reinforcing bars placed out of plane was used for loading the beams. The test results were compared with various lateral buckling solutions in the literature and the solution developed in this study, which accounts for the inelastic and non-homogeneous nature and cracking of reinforced concrete and the initial geometric imperfections. Tests have shown that sweep increases the lateral deformations of a concrete beam before buckling and reduces the buckling load. The proposed analytical solution was found to closely estimate the experimental buckling loads of the specimens.