Experimental Investigation on Shear Behavior of Double Sided Reinforced Concrete Corbels Using BFRP Bars

A reinforced concrete corbel is a short cantilever structural member extending from columns or walls, resisting mostly vertical loads by shear action. The paper presents an experimental investigation on the shear behavior of reinforced concrete corbels reinforced longitudinally with Basalt Fiber-Reinforced Polymer (BFRP) bars as an alternative material to conventional steel reinforcement. Eight double-sided reinforced concrete corbels measured 180mmx300mm and a central column segment 180mmx300mm, with different longitudinal reinforcement of BFRP ratios (1pb, 1.57pb, 3.15pb, and 5.6pb) and shear span-to-depth ratios (a/d = 1.0 and 1.25) were tested under an experimental program. In specimens with a/d = 1.0, an increase in reinforcement ratio to 5.6pb resulted in an ultimate shear strength increase by 34.25%. Nevertheless, at the higher shear span-to-depth ratio (a/d = 1.25), the largest shear strength increased about 67.6% at 3.15pb, beyond this ratio, the shear strength significantly decreased to 42.7% at 5.6pb, indicating reaching the optimal limit. These results validate the efficiency of utilizing BFRP reinforced polymer bars to increase shear capacity in concrete corbels and choosing the reinforcement ratio to induce optimal structural behavior.