Austroads Report: The benefits and challenges of using recycled plastics in asphalt and sprayed seals

With plastic a significant contributor to Australia’s waste generation and with more and more ending up in landfill each year, many industries are looking to develop new ways to reuse and recycle plastic. But is recycled plastic a viable alternative for the construction of roads? And what are the long term health and lifestyle implications? On behalf of Austroads, Level 5 Design Principal Consultant Christina Chin with support from CEO Peter Damen have written a fascinating report on the benefits and challenges of using recycled plastics in asphalt and sprayed seals. 

​The basis of the report involved conducting a comprehensive local and overseas literature review, looking at a number of case studies and overseas road trials. The report found that some waste plastics can be a partial aggregate replacement in bituminous mixes and a binder extender without significantly influencing asphalt properties, however a precautionary approach has been advised until more research has been conducted. One of the most significant concerns is that road workers could be exposed to hazards whilst handling recycled plastics and there is also the potential issue of emissions being released when plastic is heated. Another concern is microplastics leaching out from our pavements into waterways, posing a threat to our marine life.

One of the main recommendations in the report is the need for the development of a governance framework on the use of plastics in road construction and to develop performance-based specifications to allow producers more flexibility to innovate. Focus should be on nationally monitoring, assessing and sharing results of road trials conducted in Australia and New Zealand and further research into the viability of using recycled plastics in sprayed seals. 

Read the full Austroads report here.