Optimizing waste management and enhancing asphalt performance: A sustainable approach using discarded baby diapers and face masks

Abstract

This research introduces an innovative approach to address the management of waste Baby Diapers (BD) and Face Masks (FM) in order to mitigate environmental risks associated with the indiscriminate disposal of BD and FM waste. The study focuses on leveraging the utilization of BD and FM in road pavement hot mix asphalt (HMA) to enhance bitumen and aggregate performance, respectively. The approach involves the direct incorporation of 4% shredded BD during the bitumen melting process, while varying percentages of shredded FM (0%, 0.5%, 1%, and 1.5% relative to aggregate weight) are utilized as aggregate coating through a melting process. The inclusion of BD enhances the modified bitumen’s (MB) resistance to permanent deformations under high temperatures compared to conventional bitumen. Simultaneously, the treatment of FM significantly improves the physical and mechanical attributes of the aggregates. The combination of 4% BD and 1.5% FM results in improved densification, fostering robust bonding between aggregates and asphalt paste. This enhancement leads to a 39% increase in stability, a 18% increase in indirect tensile strength, and a 27% reduction in permanent deformations. Notably, there is a remarkable 53% increase in resistance to rut depth and a 33% increase in resilient modulus. Ultimately, the implementation of 4% BD as a bitumen enhancer and 1.5% FM as an aggregate modifier demonstrates the potential to achieve waste reductions of 36% and 61%, respectively. This approach extends beyond pavement enhancement, contributing to the broader societal mitigation of adverse effects associated with BD and FM waste.