Sustainable RC Beams with Agricultural Waste Fine Aggregate and Glass Powder: Structural Evaluation under Bending

Background This experimental study evaluates the structural behavior of reinforced concrete (RC) beams incorporating walnut shell fine aggregate (WFA) and 15% powdered waste glass (PWG). Method Eight simply-supported RC beams were cast and tested in two series: Group 1 (beams with transverse stirrups i.e. flexure-dominated) and Group 2 (beams without stirrups i.e. shear-dominated). Mixes included a control (0% WFA) and three WFA replacement levels (10%, 20%, 30% by volume of sand), with PWG fixed at 15% of cement in all mixes. Tests included 28-day compressive strength, density measurements, and two-point bending load–deflection tests. Results Results show that 10% WFA replacement enhanced compressive strength by 3–5%, flexural capacity by ~6%, and ductility by 64%, while reducing density by 6–8%. Higher WFA contents reduced stiffness but improved energy absorption and crack distribution. Conclusions The findings confirm that moderate WFA replacement (≤10%) combined with PWG yields eco-efficient RC beams with improved ductility and reduced dead load.