The influence of palm kernel shell on the shear behaviour of reinforced concrete deep beams

Rising construction costs and environmental concerns necessitate the exploration of sustainable alternatives for conventional building materials. This study investigates the influence of palm kernel shell (PKS) on the shear behaviour of reinforced concrete deep beams. A high strength lightweight concrete of grade 40 was prepared using palm kernel shell as coarse aggregate. Three pairs of deep beams, with and without shear reinforcement, of 150 mm width and 350 mm depth, having shear span-to-effective depth ratios of 1.0, 1.5 and 2.0, were prepared for the PKS reinforced concrete deep beams. The beams were cured for 7, 14, 21, and 28 days and tested for ductility and shear strength under three-point loading. The experimental results showed comparatively that the average ductility ratio of the PKS concrete deep beams without shear reinforcement was 1.6 times that of the normal weight concrete (NWC) whilst for the beams with vertical shear reinforcement, the ductility ratio was 1.3 times that of the NWC, showing superiority of palm kernel shell concrete (PKSC) over NWC in terms of ductility. Also, the normalized shear strength of the PKSC deep beams was found to be higher than the NWC samples at all a/d ratios. It was concluded that PKSC deep beams exhibit higher ductility and normalized shear strength characteristics than NWC deep beams which can be considered as a sustainable material.