Moment redistribution assessment of continuous reinforced concrete beams of hybrid concrete strength: Experimental study

The current study intends to use moment redistribution concept besides the smart utilization of concrete strength to develop continuous reinforced concrete beams using hybrid concrete of normal and high strength grades in addition to investigates the effectiveness of introduced hybrid modes upon moment redistribution and related issues such as strength capacity, load deflection response, flexural stiffness, flexural ductility, and the mechanism of failure. The experimental program consists of manufacturing and testing six specimens of 3000×200 120 mm divided into two groups, the first one related to specimens of homogeneous concrete strength of, 60 MPa which denoted as high strength and the second group related to specimens of hybrid concrete strength the layer of 60 MPa and the lower layer of 20MP. Although of the significant reduction in section strength of in lower layer in hybrid mode for one third (from 60 to 20 MPa), the results depict that, the moment capacity, flexural stiffness and flexural ductility tends to get improving with the mid span enhancement rating increasing which is compatible with attained moment redistribution.