The effect of critical regions reinforcement on the flexural capacity and moment redistribution of RC continuous T-beams (Experimental and Numerical study)

Despite linear analysis in several design codes for concrete structures, with re-distribution of moment in RC continuous beams. However, in deciding the importance of moment redistribution ratio in these codes and its meaning in the design, there is a strong mismatch due to ignoring several variables that have a direct effect on the load carrying capacities and the serviceability limits, which in turn leads to very conservative or unsafe designs. This paper aims at developing models of 3D nonlinear finite elements (FE) and investigating numerically the influence of the tensile reinforcement of sagging and hogging region on the performance of the RC continuous T-beams and their effect on the moment redistribution by using three experimental specimens for verification. The three two-span RC continuous beams were manufactured and tested up to failure, and designed with a loaded central concrete column. The results show that the sagging reinforcement improves the ductility and the serviceability of the continuous beams at the allowable deflection and the permissible crack width. The moment redistribution ratio depends on the ratio between the sagging reinforcement and the hogging reinforcement areas. At the hogging and sagging regions with equal reinforcement areas, the momentum redistribution ratio is low, regardless of the reinforcement ratio.