Behavior of reinforced concrete solid and hollow beams that have additional reinforcement in the constant moment zone

Abstract

This paper presents the effect of non-uniform reinforcement ratio along the beam length on the flexural behaviour experimentally and numerically. Within the experiment, four reinforced concrete beams each had a different reinforcement ratio. However, three of four beams had a similar reinforcement ratio in the constant moment zone (0.012). Cracking load, load carrying and deflection were monitored through the test. A nonlinear finite element software was implemented to simulate the experimental behaviour. Followed up by a parametric study. It was found that, in reinforced concrete beams, the tension stiffening depends on the concrete area in the tension zone not the reinforcement ratio. FEA predicts the reinforced concrete beams behaviour within a good agreement. Finally, the findings show that, determining variable amount of reinforcement ratio along the beam length will not sacrifice the flexural behaviour, but it will reduce the quantity of the steel reinforcement and the overall cost.