PERFORMANCE OF PERVIOUS ASPHALT PAVEMENT USING WASTE POLYETHYLENE MODIFIED BINDER

Abstract

The escalating demand for sustainable and resilient pavement solutions, coupled with growing environmental concerns regarding polyethylene waste, has catalyzed the exploration of innovative materials within pavement engineering. This study undertook an experimental evaluation of pervious asphalt pavement utilizing waste polyethylene-modified bitumen to enhance mechanical strength and functional durability, while promoting sustainable waste repurposing. In Bangladesh, where the rainy season lasts nearly seven to eight months, conventional pavements face persistent drainage challenges and reduced lifespan. In this study, 60/70 penetration grade bitumen was modified by incorporating 3%, 4%, 5%, and 6% waste polyethylene by weight. Binder tests— including penetration, softening point, ductility, viscosity, temperature susceptibility, and others—revealed that 4% polyethylene addition produced the most favorable results. The modified binder exhibited enhanced stiffness and lower susceptibility to temperature changes, with penetration values ranging from 11 at 5°C to 49 at 35°C, compared to 6 to 152 for unmodified bitumen. The optimum binder content (OBC) was determined to be within the range of 5.25 5.4%, based on Cantabro abrasion and draindown test results. The mix satisfied the Cantabro loss threshold of 15% and the maximum allowable draindown limit of 0.3%, as per MS-2. The air void content was also verified to be within the range of 18–22%, ensuring adequate permeability. Performance tests showed that polyethylene-modified mixes outperformed conventional mixes. Dry Marshall stability increased from 1.86 kN to 4.70 kN, and retained stability improved from 71.5% for the neat binder to 90.4% for the v modified mix, exceeding the minimum requirement of 75%. The Tensile Strength Ratio (TSR) also improved from 85% to 97%, indicating higher resistance to moisture damage. The coefficient of permeability increased from 3 mm/s in conventional mixes to 4.2 mm/s in modified mixes, confirming improved infiltration potential. These findings confirm that incorporating waste polyethylene enhances the structural and functional performance of pervious asphalt pavement, while also addressing environmental waste concerns. The proposed mix shows promise for low-volume roads and parking lots, particularly in high-rainfall regions, and offers a basis for future field applications and study.