Stabilised Pavements of Australia (SPA) is one of the many key industry bodies helping to turn the tide around the awareness and the application of recycling pavements. Executive General Manager Daniel Orriss and the SPA team are leading this charge.
Australia has a long way to go if it’s to achieve its goal of cutting emissions by 43 per cent by 2030 and reaching net-zero by 2050, with Climate Action Tracker currently assessing Australia’s progress as “insufficient”.
To put this into perspective, according to Sustainability Victoria, more than 500 quarries produce about 500 million tonnes of heavy construction materials every year. Additionally, each Victorian requires, on average, eight tonnes of quarry material annually to support the building of roads, houses and other infrastructure to service their needs.
Now imagine this impact across all states and territories. The infrastructure and roads sectors rely heavily on raw materials, as such the importance of sustainable materials and alternatives has grown significantly.
Pavement recycling and stabilisation is a solution that’s available and ready to use right now to solve challenges of resource limitation and emissions targets. Despite this, there appears to be a reliance on virgin materials in many infrastructure applications, commonly through the use of asphalt, cement-treated base or granular materials.
So why isn’t the industry making the most of this opportunity?
That’s the question that Stabilised Pavements of Australia has been supporting clients to answer for decades. Since 1983, SPA has focused on developing innovative pavement projects and formulations for the betterment of the road construction and rehabilitation sector.
Having worked with state road authorities, local government, civil construction companies and more, SPA has experience completing a variety of road construction projects. It’s also experienced in being the voice for the pavement sector, helping to represent and advocate for improved outcomes.
For Daniel Orriss, as the Executive General Manager of SPA, sustainability is a topic of upmost importance not only to himself, but also his team.
He says achieving widespread use of sustainable pavement techniques, as well as stabilisation, is the main goal. But there’s a number of key steps that the sector must satisfy before this target is met.
“The issue is twofold,” he says. “Firstly, there’s some improvements that need to be made around education and awareness that pavement recycling exists and the well documented engineering process required to produce outcomes.
“When people are coming into roles as Asset Managers, and the Asset Owners themselves, they’re quickly shown virgin material or asphalt options rather than recycled alternatives. Their first option should be using engineering principles of investigating the existing pavement materials and considering what recycling solutions are available.”
Another important aspect that Orriss says will play a big role in encouraging the use of recycled materials, is the support of the next generation.
“We know that younger generations tend to have values that align with looking at sustainability, they’re naturally inclined to be looking at those elements from their own personal values and beliefs,” Orriss says.
Educating not only the next generation, but also those who are already in the sector is another major priority for SPA.
“The older generations bring with them previous experiences, both good and bad with respect to pavement recycling. Our sector in the past 20 years has gone through a significant amount of change when it comes to science, technology and design convention, however many experienced industry representatives are unaware of these significant improvements and how they subsequently separate today’s industry from the past,” Orriss says.
Another challenge is dissolving the barrier of risk adversity and encouraging innovation. While this is an essential consideration for infrastructure delivery, Orriss says that relative incentives to innovate to further promote the process of recycling pavements are lacking and says industry and government leaders and policy makers need to drive this innovation.
“Designers and consultants are incentivised to minimise their individual risk, and they’re not always necessarily incentivised to save money or bring about sustainable and resilient outcomes for the asset owner,” Orriss says.
That’s where SPA plays an important role – in dispelling misinformation and clarifying the benefits of recycling pavements. As part of this journey, SPA is aspiring for recycled pavements to always be the primary option for road rehabilitation, and other options considered secondly.
“We’re a national organisation with a strong engineering team and we rely on our team interacting with asset owners to maintain that conversation, mainly around the educational piece and working with them around the options that are currently available and best suited to their needs,” Orriss says.
“We also have our own internal design department called SP Design, where we’re able to provide and offer technical solutions to the market. We can work closely with consultants, councils and other clients on how to navigate the engineering process.”
Orriss considers SP Design as a resource that can help to bridge gaps in technical knowledge. This enables SPA to increase the accessibility of sustainable options for clients.
Issues and solutions
Orriss says the use of sustainable solutions within the sector is gaining momentum, namely through policy direction from the Federal Government, as well as some state governments.
“There’s been a number of natural disasters and periods of extreme rainfall that have deteriorated road assets to the point where we need to have a look at current practices,” Orriss says.
“Last year, the Federal Government released a report (National Climate Resilience and Adaptation Strategy) that detailed some recommendations around building more resilient assets in the face of adverse weather events. Infrastructure Victoria similarly released a policy that identified the strategies that need to be put in place to improve its network in the future (Weathering the storm: Adapting Victoria’s infrastructure to climate change).”
Importantly, both reports highlighted the potential, and need for pavement recycling and resilient solutions. These reports drew upon the experience of the Queensland Government, which went through a similar process after multiple natural disaster events a number of years ago.
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The Infrastructure Victoria report in 2024, titled Weathering the Storm, provided a variety of recommendations for the Victorian Government. This came off the back of estimations that climate-related damage could cost the state $115 billion by 2030 and more than $986 billion by 2100.
SPA is hoping to promote a proactive approach, where infrastructure spend is directed towards more resilient and sustainable pavement types, leading to greater pavement longevity and reduced material use in the long run.
This approach would also help to stop the pattern of what SPA refers to as the “vicious cycle”. That is: flood damage – repair – flood damage – repair.
Another key aspect is reduced cost. Road repairs are now costing municipal areas more than ever before, making widespread repairs more difficult. This issue is confounded by the reductions in federal and state funding for many councils.
“There’s still a bit of a disconnect between operation components and policy direction. But we’re seeing that progressively close in procurement for example. Design requirements are slowly driving more sustainable, cost-effective and resilient solutions,” Orriss says.
“It’s a matter of developing better policy that’s well suited and the asset managers and infrastructure departments delivering on policy outcomes.”
To aid this progress, SPA has developed an Environmental Calculator, a tool that can be used to further understand the environmental benefits of using pavement recycling through stabilisation. A development that the SPA team is particularly proud of and is championed by SPA’s Sustainability Lead, Davina Smith.
“What makes our model different is that it’s fit for purpose. Other models out there can provide a more holistic look at sustainability, including the social elements, but the SPA model can enable a state or authority to look at a one-kilometre-long project, to evaluate the different options easily and quickly,” he says.
This calculator has been developed by SPA over the past 10 years and draws upon international and Australian convention for how processes are undertaken and how to best model outputs.
As part of its pavement recycling and insitu stabilisation solutions, SPA has a number of methods that are equally effective and sustainable to tackle frequent road wear.
Its base grade stabilisation method – the process of blending existing granular materials and subgrade materials to increase the pavement depth – is just one example.
“From an engineering perspective, municipalities can also have pavements that are fairly thin in terms of their existing pavement material, since most of these were constructed 50 years ago,” Orriss says.
“Our base grade stabilisation method incorporates both the existing pavement and the subgrade materials, there’s a specific flowchart and engineering process that we’ve developed and this is a game changer for a lot of local government associations in terms of the cost benefits that it produces.”
Future hopes
When it comes to the future, Orriss says the plan of attack for SPA is to grow and improve its range of solutions, while also advocating for improved development and maintenance funding.
Despite on-going challenges, Orriss says there’s a positive path ahead for the sector, led by further developments in the sustainable material space.
“For engineering materials such as bitumen, cement lime and so forth, they’re currently carbon intensive products to produce,” he says.
“The positive change that we’re seeing in the sector is exciting. Our organisation has always understood the sustainability benefits and now we’re starting to see the needle move in a positive way.
“We collectively need to be the ones driving that change.”
This article was originally published in the August edition of our magazine. To read the magazine, click here.