Ductility and cracking behavior of reinforced coconut shell concrete beams incorporated with coconut shell ash

Coconut shell concrete beams containing coconut shell ash are a feasible alternative to traditional reinforced concrete beams in structural applications. Coconut shells in reinforced concrete beams are essential in earthquake-prone areas because of their ductility properties, which contribute to enhancing earthquake resistance. This research investigates the flexure, ductility, shear, and cracking behavior of reinforced concrete beams made from the incorporation of a minimum quantity of untreated coconut shell particles (CSP) at 5% substitution of coarse aggregate (CA) modified with coconut shell ash (CSA) at 10% substitution of Ordinary Portland cement (OPC). Two beams were evaluated for flexural, strain, ductility, and cracking behavior. In contrast, the other two were evaluated for flexural, shear, strain, ductility, and cracking behavior by repositioning the loading point to the distance of 200 mm close to the support. In comparison to control beams evaluated for flexural, shear, strain, ductility, and cracking behavior, the ductility ratio of concrete beams with 10% CSA and 5% CSP improved by 8.8%. The ductile improvement was observed with a 17.3% decrease in flexural load. The shear capacity of reinforced concrete beams with 10% CSA and 5% CSP improved compared to the reference literature in the study. Finally, it was discovered that combining 10% CSA and 5% CSP in reinforced concrete beams can improve ductility without significantly reducing ultimate failure load.