Cracking behaviour of concrete beams reinforced with face mask-derived polypropylene fibres

This research investigates an environmentally sustainable construction approach by evaluating the feasibility of using shredded medical waste gowns and face masks as fibres in concrete. The study focused on the influence of face mask-derived fibres on the cracking behaviour of full-scale reinforced concrete beams under service flexural loading. An experimental program involving four-point bending tests was conducted on fibre-reinforced concrete (FRC) beams with fibre volume fractions of 0%, 0.25%, and 0.5%. The results showed notable improvements in concrete performance, including up to 23% enhancement in tensile strength and up to 40% increase in beam cracking capacity. Experimental crack width and crack spacing values were compared with predictions from existing FRC models, including Eurocode 2, Model Code 2010, ACI Committee 544, RILEM TC 162-TDF, and other published studies. Eurocode 2 and Model Code 2010 provided reasonably accurate predictions for plain concrete beams; however, prediction accuracy for beams containing face mask fibres varied depending on fibre content. The findings demonstrate the potential of incorporating medical-grade face mask waste into reinforced concrete beams and highlight the need to modify existing crack prediction models to better account for non-metallic fibre content in structural design.