Asphalt is one of the most recycled products in the construction industry, a trend driven by the high price of bitumen and increasing scarcity of crushed aggregates. Now, the release of internationally-aligned benchmarking tools means road managers can be sure they are choosing the right sustainable products for the job. 

Robert Vos, Executive Director of the Australian Asphalt Pavement Association (AAPA) Queensland and Northern Territory, says the “fiercely competitive” asphalt industry has forged ahead with innovative recycled solutions, such as looking at the substitution of waste products from other sectors, improving durability and lowering energy and C02 equivalent emissions.

“Sustainable alternatives are recognised as meeting customer goals and, when developed, bringing operational and cost saving advantages,” Vos says.

“All new asphalt has an increasing percentage of recycled asphalt pavement (RAP). Most specifications allow for the routine inclusion of 15% and higher percentages to 40% with some additional design conditions. Asphalt with lowered temperature of manufacture as well as RAP is routine and likely standard practice where permitted on most local government asphalt.

“Asphalt with additional sustainability features such as tyre crumb rubber, toner ink and glass continues to expand into the market.”

In an effort to ensure road owners and end users are getting the best results as these new products hit the market,  AAPA has developed a suite of benchmarking tools.

“The Australian asphalt industry is linked internationally through a Global Asphalt Pavement Alliance (GAPA),” Vos explains.

“We have monitored what has been done in Europe and the US to reach a common, scientific assessment of the environmental impact of asphalt manufacture.”

Vos says that AAPA consulted with its international colleagues from GAPA to assess the international ‘calculator’ used to input and rate the environmental impact of the manufacturing of asphalt. This ‘calculator’ is the Product Category Rules (PCR), which uses local and international databases covering all the inputs and actions in determining the carbon dioxide equivalent (CO2e) for asphalt.

The result of the PCR calculation is an Environmental Product Declaration (EPD) which provides a clear, internationally benchmarked CO2e value which can be used to compare asphalt from different sources.

“PCRs cover what is to be included in the raw materials, transport and manufacturing of asphalt. The PCR draws from local and international sources of life cycle assessment data which then ‘calculates’ the EPD result.  So, it is designed to provide a uniform and transparent assessment of the environmental impact, able to be evaluated against international norms,” Vos explains.

The EDPs ensure the sustainable claims are consistently calculated and communicated and undergo the relevant levels of scrutiny. Asphalt producers are also able to gain recognition for their better than generic energy reductions, waste material substitution, lowered production temperatures and increased percentage of reused materials. 

The first asphalt EDPs are expected in late 2018.

Why are these tools important?

Vos says the impact of these decision-making tools will be increased confidence in sustainable asphalt products, both for road owners and communities.

“It is fundamental that there is confidence in the measures that the asphalt industry uses to report and prove its sustainability claims,” he says.

“That is why the EPDs issued in Australia will be to international norms and the industry will be able to fast-track sustainability improvements from around the world.

“Reducing the impact on consumption of scarce and expensive resources is clearly important to the broad community. It is important to share that industry is committed to continually improving the sustainability of asphalt both in recycling, reuse, repurposing to higher value and including  current ‘waste products’ such as old tyre rubber, glass, toner. And, improved sustainability through longer lasting, more durable asphalt brings cost savings to all.”

What’s next?

The AAPA is also investigating a better way to measure whole-of-life costs.

“The environmental impact of supplying a product or service does not reflect its impact in use. In the road sector the use of whole-of-life costs often only considers the cost to the road owner and not the road user. When considering sustainability, the user benefit, or user dis-benefit due to poor service levels, should be part of the life-cycle assessment,” Vos says.

“For example, the life-cycle assessment considering the environmental impact of two products, one which stays smooth and un-potholed longer that the other, should be included in the whole-of-life cost assessment. 

Currently this is only indirectly included and relative performance data is limited.”

Vos says AAPA has plans to capture this information for some generic products and will be working with road owners to include this in their maintenance and operational decision making. 

To learn more about the future decision-making process for sustainable asphalt, don’t miss Robert Vos’ presentation at the IPWEA Sustainability in Public Works Conference, 14-15 May, Sydney.