Environmental Assessment of Asphaltic Wearing Course Containing Mixed Plastic Waste in Singapore

Presently, the amount of plastic waste generated globally has doubled since the early 2000s yet the recycling rate for plastic waste remains below 10%. The accumulation of mixed plastic waste in municipal solid waste streams have spurred immense interest in recycling mixed plastic waste as polymer-modified bitumen in asphalt mixtures for pavement applications. This paper presents the findings from laboratory tests and field investigation conducted to evaluate the environmental properties of a novel mixed plastic modified asphalt mix. The laboratory works carried out include leachate characterization and microplastic detection assessment. Subsequently, full scale wearing course sections were constructed with control and mixed plastic modified asphalt mixes for field investigation. Groundwater and surface runoff samples were collected and analysed to provide valuable insights on the environmental properties and field performance of mixed plastic modified asphalt mixtures in operative conditions.