Torsional behavior of reinforced recycled aggregate flowing concrete hollow section beams

Abstract

Fifteen reinforced concrete beams made with recycled aggregates and flowing concrete, which were tested under pure torsion to study the torsional behavior. The major parameters in this study were the percent of the recycled aggregates and the number of transverse reinforcements. The torsional response and crack behavior were investigated in this study. From the results, it can be noted that the increase of the recycled aggregate led to a decrease in the critical and ultimate torque of the beam, also, the increasing the number of transverse reinforcements led to the enhancement of the critical and ultimate torque. Numerical analysis by finite element method was conducted and gave a good indicator for agreement in the results of critical and ultimate load between the numerical and experimental study, as well as the angle of twisting of the beam. The second approach was Hsu᾽s softened truss model, the model proves it can predict the critical and ultimate torque for the beam and showed its ability to describe the behavior of the beams before and after cracks.