Muhammad Umer Amin Khan

In the era of the global drive for sustainability in line with the United Nations Sustainable Development Goals (UN SDGs), sustainability measures are encouraged to be taken at all levels. This study explores a novel mix design integrating Reclaimed Asphalt (RAP) with waste Polyethylene Terephthalate (PET) to enhance pavement performance and sustainability. It adopts a holistic approach by investigating the technical, economic, and environmental aspects of the proposed mix to assess its sustainability. Industry experts emphasize the necessity of mitigating the resource intensiveness of pavement construction to foster sustainable infrastructure. RAP enables resource-efficient pavement construction by promoting asphalt recycling. However, increasing RAP quantity in the mix compromises asphalt structural stability, making it more susceptible to moisture damage and rutting. In this study, PET-modified Bitumen (PMB) is incorporated in higher RAP quantities in the asphaltic mix without compromising asphalt’s structural performance and durability. Various PMB amounts (2% to 10% by mass of mixture) were tested with 40% RAP (by mass of mixture), evaluating performance in terms of moisture damage, Marshall stability, rutting, etc. Optimal results were achieved with 6% PET and 40% RAP, showing a 7%, 57%, and 23% improvement in moisture resistance, rutting resistance, and Marshall stability, respectively, compared to unmodified asphalt (technical aspects). The novel asphalt mix demonstrated a 17% reduction in material cost (economic aspect) and a 53% decrease in CO₂ emissions (environmental aspect) using Building Information Modeling (BIM). This study devises a prospective solution for the construction of resilient, resource-efficient, cost-effective, environmentally friendly, and sustainable pavements in line with UN SDGs and circular economy goals.

In this study, the structural performance and sustainability of Reclaimed Asphalt used in combination with PET Modified Asphalt as a rejuvenating agent were assessed. This study involved the utilization of aggregate, grade 60/70 bitumen, and crushed plastic bottle waste. Polymer Modified Bitumen (PMB) was created by combining these materials in a high-shear laboratory mixer rotating at a speed of 1100 rpm.Different amounts of PET content, namely 2%, 4%, 6%, 8%, and 10% were used in the preparation of PMB.Samples were prepared using the wet mixing method. Performance evaluation tests, including the MoistureSusceptibility Test (ALDOT-361-88), Indirect Tensile Fatigue Test (ITFT-EN12697-24), and Marshall Stability and Flow Tests (AASHTO T245-90), were performed on controlled and modified Hot Mix Asphalt (HMA) samples. The samples of RAP-PMB modified asphalt yielded improved results than other materials under study. Mostly, optimum results were recorded with RAP-PET samples containing 6% PET. Further, increase in PET % caused a decline in performance. The sustainability assessment was done using BIM.Autodesk Infraworks and One Click LCA were used for economic and environmental assessments. The RAP-PMB modified asphalt had a lower carbon footprint and materials cost than other specimens due to the significant replacement of fresh asphalt.