Innovative friendly-environmental hybrid model of precast reinforced concrete deep beams based on curved hybridization

A new sustainable composite model of hybrid deep beams has been proposed and compared to the conventional deep beams. The suggested model which is called (arched model) and was based on using steel fiber concrete (SFC) with a fiber ratio of 1%, which is used in areas with high stress concentrations. While the sustainable concrete with replacement ratios of 0%, 50%, and 100% from recycled coarse aggregate (RCA) is used in other areas. Seven specimens have been tested experimentally under mid-span static loading with a shear span to depth ratio (a/d) of 1.7. The behavior has been studied in terms of failure load, cracking load, load-deflection curve, cracking pattern, toughness, stiffness and ductility. Results revealed that good enhancements in toughness, effective stiffness and ductility relative to the conventional deep beams. Maximum enhancements in toughness, stiffness and ductility were 100%, 11% and 46% for the specimen with full (RCA) replacement relative to the corresponding conventional deep beam.