Studies on rotation capacity and torsional strength of normal, medium- and high-strength rc beams

Abstract

Understanding of the beam behaviour in torsion along with bending and shear is very important for the complex design of buildings and as well as recent developments in neo-concretes. An experimental investigation was carried out to determine the response of normal, medium- and high-strength concrete beams when subjected to torsion. In the present investigation under standard testing conditions, the torsional behaviour of total 27 beams which are grouped into nine categories like NSC, MSC and HSC beams with identical geometrical conditions like width, depth, effective span and varied area of steel in longitudinal and transverse directions has been investigated. The beam properties like rotation capacity, ultimate torsional strength and failure pattern of the beams are studied. The results obtained from the experimental investigations are validated with the help of similar work as cited in the literature survey. Also, the parametric analysis had carried out for different models, theories and codal equations as suggested by the different investigators. The obtained torsional strength experimental values of NSC beams are well agreement with the predicted torsional strength for most of the codes available in the literature. The experimental values of MSC and HSC beams are close agreement with EURO code II results. It was also observed that the rotation capacity of the beams depends on the grade of concrete, longitudinal steel and spacing of transverse reinforcement. © Springer Nature Singapore Pte Ltd 2021.