Experimental Investigation for Behavior of Reinforced Hybrid Concrete Corbel-Column System Subjected to Un-Symmetrical Vertical Loading

Abstract

In this paper, shear and flexural behavior of reinforced hybrid concrete corbel-column system was experimentally investigated. Fourteen hybrid and homogenous concrete corbel-column systemssubjected to un-symmetrical loading were constructed and tested within two test groups (A, B). The experimental program included several variables such as: type of hybrid concrete;high strength concrete(HSC) or steel fiber reinforced concrete(SFRC), shear span to depth ratio (a/d), area of hybridization in corbel - column system.Experimental results showed significant effects of concrete hybridization on structural shear and flexural behavior including: ultimate strength, cracking loads, cracking patterns, failure modes, and ductility. Hybridization process ingroup (A) included casting the corbel with HSC or SFRC instated of normal strength concrete (NSC). In shear behavior corbels (a/d= 0.37), this process led to increase the shear capacity of corbel by (26%, 38%) and shear cracking loads by (20%, 120%) respectively. Furthermore, in flexural behavior corbels (a/d= 0.74) shear capacity increased by (19%, 42%), flexural cracking loads increased by (29%, 143%) for HSC and SFRC corbels respectively. In group (B) hybridization process included increasing the hybrid area of corbel-column system in group (A) to represent a distributed region (D-region) or decreasing it to represent hybrid corbel. In both cases shear capacity of corbel increased with a range of (10 to 41) % for specimens hybridized monolithically with HSC, while it increased with a range of (19 to 44) % for specimens hybridized monolithically with SFRC; compared with homogenous NSC specimens having same (a/d) ratio.