Structural behavior of non-prismatic reinforced concrete frames using hybrid concrete under repeated load

This study deals with the experimental investigation of the behavior of a non-prismatic reinforced concrete frame ade of Normal Strength Concrete (NSC) and hybridized with Glass fiber Reactive Powder Concrete (GRPC) under repeated loading. The requirements of construction projects are for concrete members with a small cross-section, and high durability at the lowest cost. Because of the high price of high-performance concrete (GRPC), it is used in specific regions with high stress concentrations. In this research, five specimens with NSC and hybridized with GRPC at different locations (shear and flexural) and proportions (25%, 50%, and 100%) are tested under repeated loading. The results showed that using GRPC in any region selected and at any percentage improves the behavior of the concrete frame in varying percentages where the ultimate load of the hybrid frame increases by (28–59%) compared to the non-hybrid frame. The best hybridization location that gives the best results and the lowest percentage of hybridization is in the lower half of the beam, where the ultimate load increases by 56%. It also makes the crack width constant throughout the loading cycles, and the crack width also remains constant with the loading cycles, and this does not exist in the non-hybrid frame as well as in the other hybrid specimens. Hybridization in the lower half of the beam also changes the mode of failure from shear failure to flexural failure.