Roads Review: Recycled materials

For the Road Review section this month, we asked the industry decision-makers, ‘What are the challenges for greater use of recycled materials in roads and pavements?’

Anna D’Angelo, AfPA’s Executive Director of Technology and Leadership.

Anna D’Angelo – AfPA, Executive Director Technology and Leadership

Since China’s National Sword policy in 2018, the Council of Australian Governments (COAG) waste export ban initiated in 2019, and the drive to embed circular economy principles across all sectors, there have been significant efforts to find solutions to recover and reuse waste stream materials. However, there are still some challenges related to negative perceptions associated with the definition of “waste” materials. There is the need of a shift in thinking to consider some of these materials no longer as waste, but as resources for the flexible pavement industry and to find new solutions. Used tyres, Reclaimed Asphalt Pavement (RAP), crushed glass, and plastics are some examples of “waste” materials that could be diverted from landfill to road maintenance and construction. To reduce our carbon footprint, greater understanding and acceptance of these alternative material sources is needed.


Dante Cremasco, Head of Road Services, Downer Group

Achieving a greater use of recycled materials in roads is a collective challenge. As Downer has been a pioneer in this area, it’s been incredibly positive to see significant changes and improvements to Australia’s procurement policies, state road specifications and recycling practices over the past few years. There has been huge momentum to solve these challenges collaboratively and we have formed successful partnerships with suppliers and state authorities to optimise the use of recycled materials while improving road performance. In order to realise Australia’s 2050 targets, asset owners will demand even lower carbon intensity – requiring superior asset management protocols, higher recycled content and trending to ambient temperatures in asphalt and bituminous products. In addition, recovering resources from existing roads is vital and our ability to carbon inset this in our supply chain will lower our footprint.


Tony Aloisio, Director, Ecologiq

The biggest constraints are time, cost, lack of knowledge and confidence in recycled products, disconnection between market supply and demand, and technical standards and specifications that do not reflect current possibilities. The Victorian Government’s Ecologiq program views these challenges as opportunities to develop an industry that is informed and intentional, working to remove barriers and fact-check myths through education, building capability and sharing experience. In two years, Victoria’s Recycled First Policy has increased the use of recycled and reused products by 50 per cent, as it requires contractors to maximise their use in transport projects.


Michael Caltabiano, CEO, Australian Road Research Board. 

Michael Caltabiano, ARRB Chief Executive Officer 

At the Australian Road Research Board (ARRB), we utilise our world-leading material science laboratories in Port Melbourne to create, assess, test and define the characteristics of recycled materials that are proposed for use in our transport infrastructure. The material science for recycled materials like crumbed rubber, crushed glass and recycled waste stream plastic is then combined with ARRB’s deep economic skills to determine the greenhouse gas emission reductions. This can also demonstrate cost savings that emerge from recycled materials use.  The biggest challenge that faces increased usage of recycled materials is the slow development of specifications that provide local governments and state agencies the confidence to call up recycled products as preferred materials in the construction and maintenance of transport infrastructure. ARRB’s national team of engineering expertise has developed standards for many next generation materials, but there is a long way to go, and we look forward to assisting the construction sector deliver great outcomes in the enhanced use of recycled materials in transport infrastructure.


Jonathan Cartledge, Director of Policy & Research at Infrastructure Australia

Infrastructure Australia, through our Market Capacity Program, is currently exploring supply constraints for the use of replacement materials in road infrastructure through a collaborative research project with the Australian Government Department of Agriculture, Water and the Environment and the Australian Road Research Board. Early findings are pointing to areas of world-leading practice that are ripe for scaling-up, but in parallel stakeholders are reporting systemic constraints including supply chain certainty, late specifications in project design, cultural barriers to innovation in procurement, regulatory obstacles, and standards. An expanded view of the potential demand for these materials will be provided as part of the 2022 Infrastructure Market Capacity report later this year.


Dr Xuemei Liu, Co-ordinator, Bachelor of Science & Design, The University of Melbourne

Given the complexity of infrastructure projects, a cross-disciplinary and multi-sector environment, involving research institutes, product developers and end-users all involved in demonstration projects can pave the way for further growth of circular economy in this sector. Local standards and specifications need to be established for performance-based design allowing flexible use of recycled materials.  More research needs to be done to fully understand the impacts on the health, safety and environmental aspects which could be brought forward by using various recycled materials in roads. To accelerate the adoption, more demonstration projects are needed to develop the confidence in the industry. (Contributors include Prof. Tuan Ngo and A/Prof. Mahdi Miri Disfani).

This article was originally published in the June edition of our magazine. To read the magazine, click here.

If you or someone at your organisation is an industry leader and would like to be a part of this monthly column in 2022, please get in touch with Editor, Mike Wheeler: 



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