The Concept of “Adjusted” Reinforcement in Reinforced Concrete Beams

Recently there has been a renewed interest in reinforced concrete research to create an optimum reinforcement layout that could satisfy the strength and deformation requirement, and in the same time to minimise the steel content used. The concept of “adjusted” reinforcement, i.e. beam with an optimum reinforcement layout that follows the principal stress trajectories of an elastic beam was introduced for this purpose. In this paper, an experimental investigation into the behaviour and ultimate shear strength of “adjusted” reinforcement, as well as stirrup-type reinforcement is presented. Truss models were used as an analytical tool to predict the internal forces and also to explain the internal action of adjusted reinforcement which contributes to the shear resistance. The results from this study showed that the adjusted reinforcement gives a better strength and deformational behaviour compared with standard reinforcement if proper detailing rule are complied to.