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The amount of residual Multi-layer Plastic Packaging (MPP) in Canada has greatly increased in the last two decades, which has economic and environmental consequences. MPP is primarily made up of two or more layers of Polyethylene (PE), Polyester (PET), Nylon (NY), and Metalized Polyester (METPET). While MPP has not been used as an asphalt modifier, some of the materials commonly found in MPP, such as PE and PET, have also been successfully used as asphalt modifiers. Nevertheless, a few recent studies have demonstrated the potential for reusing MPP as an asphalt modifier to improve asphalt pavement performance. Recycling post-industrial MPP instead of using raw polymers could lead to economic and environmental benefits. However, a comprehensive study to evaluate MPP as a viable asphalt additive is lacking. The main objective of this study is to evaluate the feasibility of using MPP as an asphalt modifier via the wet method, considering the physical, thermal, rheological, and storage properties of the MPP-modified binder at different MPP concentrations (2%, 4%, and 8%) in asphalt cement (PG 58–28). MPP-modified binders were evaluated using the following instruments: Differential Scanning Calorimeter (DSC), Thermogravimetric Analysis (TGA), Superpave Dynamic Shear Rheometer (DSR), Rotational Viscosity (RV), and Environmental Scanning Electron Microscopy (ESEM). Test results indicated that the incorporation of MPP has a strong potential to improve permanent deformation resistance at high temperatures. In addition, MPP shows a moderate impact on fatigue cracking performance at intermediate temperatures. Overall, in low-temperature climates, using less than 4% of MPP additives would offer higher fatigue damage resistance along with adequate permanent deformation. In high-temperature climates, higher concentrations of additives may be preferable to resist permanent deformation. Finally, MPP is a challenge for existing recycling systems, and its incorporation into asphalt applications may develop more sustainable materials that would contribute to circular economy principles. [ABSTRACT FROM AUTHOR]

Modifying asphalt binders is an effective method of improving the performance of asphalt pavement, such as its resistance to rutting. However, because modification changes the behaviour of binders, substantial laboratory testing is required before field application to determine the best mixtures. This research aimed to evaluate the impacts of temperature, stresses, polymer type, and modification rate on the rutting behaviour of the asphalt binder modified with fly-ash-based geopolymer (GF), styrene butadiene styrene (SBS), and a combination of SBS and GF. The rheological properties of asphalt binders were investigated using the frequency sweep test at various temperatures. Additionally, the multiple stress creep recovery test was conducted at various temperatures and stresses to calculate the non-recoverable creep compliance (J n r ) and the percent strain recovery (R). The rutting resistance of asphalt mixture was assessed using the Hamburg wheel rut test. The results revealed that the asphalt binder with 8% geopolymer (8%GF) exhibited the best response in terms of complex shear modulus (G * ), rutting factor (G * /sin δ), R, and J n r compared to the 4%GF and 12%GF at different temperatures. Another interesting finding is that GF's use in the hybrid binder (2%SBS + 8%GF) led to a significant increase in the shear complex modulus and a decrease in the phase angle compared to the binder modified with 2%SBS. The geopolymer decreased the binder's sensitivity to temperature for both unaged and RTFO asphalt binders. The hybrid binder would also improve strain recovery under high stress and temperatures and the ability to withstand severe traffic loads. Furthermore, there is a crucial relationship between temperature and J n r , which could help asphalt pavement designers select suitable modifiers considering the local climate and traffic volume. [ABSTRACT FROM AUTHOR]