SAMI Bitumen Technologies and the VSA Group have partnered to transform traditional microsurfacing techniques, paving the way for a new iteration.
Whether it’s crack sealing, joint sealing, pothole repair, or patching, methods of road rehabilitation continue to evolve and improve to keep up with Australia’s ageing road network.
Some of these methods are benefitting from both international innovation and collaboration between the best minds in the infrastructure sector. Microsurfacing, is just one of them.
Microsurfacing is a pavement preservation technique that involves applying a thin layer of a specialised mixture to the surface of a road. This mixture includes modified bitumen emulsion, water, aggregate, cement, and other additives. Microsurfacing is usually thinner than traditional asphalt overlays, usually between 3-10 millimetres, and is used to treat minor surface irregularities such as small cracks, while also improving the skid resistance of the existing pavement surface.
Designed to extend the service life of the pavement by protecting the underlying surface from further deterioration, it provides a cost-effective alternative to more extensive pavement rehabilitation or reconstruction projects.
Microsurfacing is a technique that’s been around for decades, but sustained innovation and research has led to improved processes. SAMI Bitumen Technologies has committed extensive resources and research towards further improving microsurfacing.
The company’s strong focus on sustainability has driven the development of products that last longer, reducing the overall energy consumption and carbon footprint required over a road’s lifespan. As such, microsurfacing plays a key role in the company’s road rehabilitation portfolio, as Brad Richards, State Manager Southern Region – SAMI explains.
“We are major players in an industry that is carbon intensive, so we feel that it’s our duty to do whatever we can to reduce our footprint on the planet,” he says.
“We’ve developed new emulsions which have a lower carbon footprint, some even have zero carbon footprint.”
To further test its advancements in bitumen emulsion, SAMI recently worked with the VSA Group (vsagroup.com.au), which has vast experience delivering sealing and asphalting services.
VSA identified that traditional road maintenance techniques using cold mix or jet patching were either prematurely failing or bleeding through the newly applied reseal. To address this, it launched its own dedicated road maintenance crew about 18 months ago to focus on pre-sealing preparation work.
In order to complete these works, the road maintenance crew acquired a specialised machine from Germany to conduct microsurfacing at a small scale. Something not commonly done in Australia.
Sylvain Clément, Business Improvement Manager – VSA Group, says microsurfacing requires compatibility between the emulsion, aggregates and the application process. As such, having a project partner such as SAMI was of significant benefit to the project.
“You need to have a good quality quarry on your side, but even more importantly you need to have good support from the bitumen emulsion manufacturers with you in the lab,” he says. “SAMI’s team has been instrumental in helping us to move forward.”
SAMI’s lab team provided support through testing and formulating, finding the right emulsion mix that would work with the aggregates from VSA’s Western Quarries. This close collaboration allowed all project stakeholders to jointly develop and refine the solution.
Clément believes that any sole attempt at such a project would only end in failure, as such the sharing of resources and information was critical.
“If we worked with someone else other than SAMI, they probably wouldn’t have spent all this development time and effort on it, because it is small-scale and niche,” he says. “Whilst the productivity of our innovative maintenance crew is significantly higher than what can be achieved by traditional patching techniques, it does not consume high volume of material on a day to day basis.
“SAMI and our trusted quarry provider, Western Quarries, have been willing to invest time and resources to boost our joint research and development efforts.”
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Project details
VSA, with SAMI’s support, has so far completed several projects across Victoria, South Australia and New South Wales, with particular success in the Golden Plains Shire (western Victoria), Naracoorte (South Australia) and Greater Hume (New South Wales) regions.
Microsurfacing was applied on a variety of road and surface types, including edge breaks, road shoulders, wheel path areas in need of regulation and lower level roads that were in poor condition.
Mark Natoli, Crew Supervisor – VSA says microsurfacing continues to grow, with the company adjusting and improving the process over time.
“The biggest selling point is having a solution to these problems that offers something better and a bit different,” he says.
“Over the past year and a half, we’ve gone from doing smaller edge breaks, to large edge breaks, backfilling rut correction and pothole patching. The expansion has been great.”
This improvement is being led by customer feedback, Natoli adds.
“We’re always trying to improve the emulsion and aggregate modifications on the machine. That mostly comes from experience and dealing with customers,” he says. “We’ve gone from doing minimal works in terms of their overall maintenance budget, to looking at whole roads. It’s been massively rewarding.”
Clément says the positive feedback has resulted in additional works with the same municipalities and regions.
“We’ve had really positive feedback and one of the first things our customers bring up is the neat finish, especially when you’re talking about edge breaks. This technique has a very neat and tidy appearance,” he says.
“One of our clients in the Naracoorte Shire gave us a week’s work. The CEO and the main engineering team came to see what the product looked like and how it performed, they were absolutely amazed. Then they gave us another job for the following week.
“Repeat customers is the best proof that your product works and that people are excited and pleased about the outcome.”
Even out in the field, Natoli says SAMI’s presence has been a constant, with their teams on standby to assist where necessary.
“Their support has been second to none,” he says. “We’ve got our own group chat, as soon as something happens, I’ve got SAMI R&D ringing me from the lab, sending test results, or whatever is required. It’s pretty much an instant response. Without their support, all of this wouldn’t have come together the way it has.”
Brad Richards, State Manager Southern Region – SAMI says the company sees its role as a supporter of innovation, helping the sector to adopt smarter and greener road treatment methods and products.
“We worked really hard with the VSA team to develop an emulsion that was stable and could provide the properties that they required. We had several variations, but it’s been a great achievement to find a balance for what their equipment required, as well as what would perform on the road,” he says.
Richards believes the technique has a bright future. Now he’s shifting his focus to spreading the word.
“It’s a relatively new process. It’s only the second year that we’ve been doing it, but when we’ve returned to the year one sites, we can already see how well it’s stood up to the elements and against heavy traffic loads,” he says. “The next challenge we face is trying to educate our clients about the benefits of the product, to get more of it out there and increase its adoption to improve our rural road networks.”
From a VSA perspective, Clément says this particular take on microsurfacing is not only “exciting”, but potentially industry altering in its capability to transform what’s considered as standard for road treatments.
“Where I’m from, emulsion is used everywhere and microsurfacing is much more developed,” he says. “Traditional microsurfacing in Australia is only used to treat one kind of application, and we have the tyranny of distance. But there is progress being made, such as the outcomes that we’ve achieved so far.
“I would love to see emulsion evolve further in Australia.”
This article was originally published in the February edition of our magazine. To read the magazine, click here.
