Modified Bitumen and Need For Research – By David Sutcliffe

Industry round table meeting to discuss promotion of the use of recyclable’s in bitumen modified road surfacing

I attended a round-table meeting of industry leaders last week, arranged by Roads Australia. The meeting was attended by delegates from major road contractors, the recycling industry, State Government and various industry associations. The purpose of the round-table was to discuss the road industry take up of rubber, glass and plastic in bitumen road surfacing.

Reuse of rubber, and to a limited extent glass, is already happening and there is opportunity to increase this. The bitumen surfacing and recycling industry believe there could be a greater take up of modified bitumen products from State Government and Local Government authorities. The financial incentive could include extended road pavement life and the productive use of recyclables otherwise being stock piled or going to landfill.

The recyclables are:

  • ·       Crushed glass as a replacement for sand;
  •         Crumbed rubber from old car tyres for improving the qualities of road surfacing making it more          durable and able to seal old pavements; and
  • ·       Possibly the use of other plastics, although this needs further research to look at durability,        OH&S and other relevant issues.

Industry concerns are understandably about risk, unknown environmental impacts, cost, OH&S, need for specifications, and proven performance.  There is a need for some definitive research on the parameters required for deciding where the products can and should be used, the impact on the longevity of pavements, the environment impact, and other related factors.

At the Roads Australia round-table, Michael Caltabiano, CEO of the Australian Road Research Board (ARRB) proposed that ARRB undertake an accelerated 3-year research program to definitively determine issues of mix design, life, and benefits of the various combinations. ARRB would require 8.5 million dollars to fund the research. Road related research was the original remit of setting up ARRB.

Apparently to date there has been no interest by government bodies in funding the ARRB proposed research.

There are probably many parallels to research led industry improvements. One example I remember occurred in the 1980’s. ARRB undertook research which led to improved road pavement design. This work has been used by road designers across Australia every day since, and was funded by the industry. The work coincidently replaced pavement design curves established by the USA military for building WW2 runways. These curves were unsuitable for road pavement design, but all that was available. That research provided a substantial step forward, leading to far more efficient road pavement designs and no doubt financial savings (probably amounting to billions of dollars over the years), and a legacy of fit for purpose pavements.

8.5 million dollars does not seem a lot compared to the billions spent across Australia on road projects every year, particularly if the research can lead to more durable road pavements or provide evidence-based decision making for additives. Combine this with the reuse of waste and you would think this is a winner.

The agreed outcomes of the Roads Australia round-table meeting were:

1.To endorse the need for national guidelines and specifications on use of recycled materials in roads;

2.To support funding for ARRB to undertake product research as they have outlined in a yet to be publicly released government submission;

3.For Roads Australia to lead a discussion with all governments on the need for a national approach to the use of recycled material in roads. Essentially this is to develop policy positions.

I would recommend we all support the funding of ARRB in undertaking the necessary research, as it will be beneficial to all road custodians by dispelling misunderstandings, targeting the beneficial uses and providing guidance and comfort for decision makers.

There are at least three ways to fund the research:

  1. ·           Direct funding by State/Federal Government;
  2. ·           Use a miniscule amount of the landfill levies funds already accumulated, and still being       collected, by state governments. This has a nice benefit/nexus for those funds; and
  3. ·           Apply an industry surcharge of say 0.1% on bitumen products for three years.

Michael Kilgariff, CEO of Roads Australia, should be congratulated for arranging the round-table initiative.

If you have taken the time to read this, I encourage you to discuss the issues with colleagues.