The Evaluation of Torsional Strength in Reinforced Concrete Beam

Abstract

Many structural elements in building and bridge construction are subjected to significant torsional moments that affect the design. A simple experiment for the evaluation of the torsional strength of reinforced concrete beams as a one of this structural elements is presented in this research. The objective of this experiments would be the role of transverse and longitudinal reinforcement on torsion strength. Four beam test samples has been tested with the same length and concrete mix design. Due to the fact, that the goal of this experiment is to determine the effect of reinforcement type on torsion strength of concrete beams; therefore, bars with different types in each beam have been applied. It was observed that the ductility factor increases with increasing percentage reinforcement from the test results. It should be also noted that transverse bars or longitudinal bars lonely would not able to increase the torsional strength of RC beams and both of them can be essential for having a good torsional behaviour in reinforced concrete beams. Introduction. The interest in gaining better understanding of the torsional behaviour of reinforced concrete (RC) members has grown in the past decades. This may be due to the increasing use of structural members in which torsion is a central feature of behaviour such as curved bridge girders and helical slabs. The achievements, however, have not been as much as those made in the areas of shear and bending. Dealing with torsion in today's codes of practice is also very primitive and does not contain the more elaborate techniques. Predictions of current standards for the ultimate torsional capacity of RC beams are found to be either too conservative or slightly risky for certain geometry, dimensions and steel bar sizes and arrangements.