Feasibility Study on the Use of Multilayer Plastic (MLP) Waste in the Construction of Asphalt Pavements

In the last few years, considerable research has been carried out in the country to determine the suitability of plastic waste in the construction of bituminous roads. That research led to establishing that linear density polyethylene (LDPE) and high-density polyethylene (HDPE)-based plastic waste can be successfully used for road construction, but there is very limited research available on the use of polyethylene terephthalate (PET)-based multilayer plastic waste in road construction. In the present study, an attempt has been made to evaluate the feasibility of using multilayered plastic (MLP) waste in the construction of roads. The properties of asphalt mixes prepared with multilayered plastic (MLP) waste have been studied, and the efficacy of different types of waste plastic for coating the aggregates was also studied. The moisture resistance of MLP-based waste plastic asphalt mixes has also been studied in comparison to PE (polyethylene) plastic waste-based and control asphalt mix. The MLP waste-modified mix showed better stability and resistance to moisture damage when compared to the PE-modified waste plastic mix. The effect of waste plastics in reducing overall bitumen demand in the asphalt mix was also studied. The heating of waste plastic to coat aggregates has always posed a concern regarding air emissions. To address this concern, the environmental emissions were measured during the coating and mixing stage. In this study, an attempt is also made to evaluate the coating of waste plastic on the aggregates using a simple approach of coatability index.