Preliminary risk assessment of polypropylene, high-and low-density polyethylene microplastics modified asphalt mixtures for road construction

One of the key parameters of a country’s socio-economic achievement is the construction of roads and highways. The technology for road construction has always been improved particularly in terms of quality and environmental aspects, for which the idea of using plastic emerged recently. Plastic roads are an auspicious strategy for lowering the quantity of land filled plastic, minimizing the dependency on depleted bituminous materials, and enhancing asphalt pavement performance. Assessing the environmental and human health aspects of the modified asphalt mixtures estimates the safety level of the product when exposed to the ecosystem. The objective of this study is to assess the preliminary environmental and human health hazards of our polypropylene (PP), high-density polyethylene (HDPE), and low-density polyethylene (LDPE) microplastics modified asphalt mixtures using fluorescence microscopy technique and polymer risk index. The mixtures were prepared by wet mixing the asphalt binder with different proportions of powdered microplastic polymers. The asphalt mixture that contained 100% HDPE had the highest crystal formation. Combining at least 5g of PP, reduced the risk index of the asphalt mixture. All the plastic polymers used in our study are ranked as the least environmentally hazardous chemicals.