Prestressed High-Strength Concrete Beams under Torsion

Abstract

Fourteen prestressed high-strength concrete beams were tested to study their torsional behavior. The major variables were the concrete compressive strength, the aspect ratio of the beam cross section, the prestressing level, and the amount of torsional reinforcement. Keeping the area constant, three different cross-sectional dimensions, 240 × 240 mm, 170 × 340 mm, and 140 × 420 mm, were used to give aspect ratios of 1, 2, and 3, respectively. The concrete compressive strengths were 70 and 90 MPa (10,000 and 13,000 psi), and the beams were subjected to two levels of prestressing, corresponding to 0.05