Enhancing Pavement Sustainability through Recycled Plastic Waste: Mechanical Performance and Environmental Assessment of Modified Bituminous Mixes

Vivek Dhiman
Head of Department, Civil Engineering, Sikkim Skill University, Sikkim.
Email: vivekdhiman121@gmail.com

Abstract

The increasing accumulation of plastic waste poses serious environmental threats, prompting researchers to explore innovative reuse strategies. This study investigates the feasibility and performance of using recycled plastic waste as a partial replacement for bitumen in flexible pavement construction. Modified bituminous mixes were developed with varying percentages (0%, 5%, 10%, 15%) of shredded low-density polyethylene (LDPE) and high-density polyethylene (HDPE). Comprehensive laboratory testing—Marshall Stability, Indirect Tensile Strength (ITS), Rutting Resistance, and Moisture Susceptibility—was conducted to evaluate performance. Additionally, Life Cycle Assessment (LCA) was carried out to quantify environmental benefits. Results indicated that a 10% plastic addition offered optimal mechanical performance, reducing deformation and increasing load-bearing capacity, while significantly lowering CO₂-equivalent emissions. This research provides a sustainable solution for both pavement durability and plastic waste management, aligning with global circular economy goals.

Highlights

A systematic study was conducted on bituminous mixes modified with LDPE and HDPE plastic waste.
Mechanical properties, including Marshall Stability and Indirect Tensile Strength (ITS), improved significantly at 10% plastic content.
Volumetric analysis revealed better compaction, reduced air voids, and increased VFB, enhancing durability.
Modified mixes showed a 48% reduction in rutting depth and a peak TSR value of 90%, indicating superior resistance to moisture damage.
An optimal plastic content of 10% was identified for balancing stiffness, flexibility, and environmental performance.
The study contributes to sustainable pavement construction by integrating performance data with life cycle assessment (LCA).
Waste plastic reuse in asphalt offers a dual benefit of improved pavement life and reduced plastic pollution.
Keywords: Plastic Waste; Modified Bitumen; Sustainable Pavement; Marshall Stability; Life Cycle Assessment; Flexible Pavement; HDPE; LDPE.