A collaboration between RMIT, SAMI, RABS and Alex Fraser has delivered works – that should’ve taken months – in just one week. Roads & Infrastructure finds out how the use of SAMIBioPrime and SAMIfalt I-brid made this outcome possible.
When Hobsons Bay City Council recognised the need to upgrade Toll Drive in Altona North, Melbourne, multiple challenges quickly came to the fore.
Toll Drive is situated in the heart of Altona North’s busy industrial precinct, frequented by a high volume of vehicles, especially freight and heavy movers.
To shut down such a road for works would cause significant disruptions, not only to local businesses, but also to what is an essential route for the transport of goods and services throughout the region.
As such, long-term shutdowns were out of the picture.
It’s here that Hobsons Bay City Council began to think outside of the box. As Aten Kumar, Coordinator, Civil Design and Projects, Capital Works – Hobsons Bay City Council explains, SAMIBioPrime and SAMIfalt I-Brid were two products that stood out.
“Every opportunity we get, we look for innovative products that not only support good project outcomes, but are also beneficial for the environment, and beneficial for the community,” he says.
For projects such as these, Hobsons Bay City Council can utilise its vast network of industry relations. RMIT is one such partner the council has been working with increasingly over the past few years.
Through discussions with Professor Filippo Giustozzi, Civil and Infrastructure Engineering Discipline Leader, Materials and Structures – RMIT, Kumar and the Hobsons Bay City Council team were made aware of two revolutionary products that could cater for the unique challenges of the Toll Road project.
SAMIBioPrime and SAMIfalt I-Brid were together presented as a more durable and sustainable solution to upgrade the existing – and ageing – Toll Drive surface and sub-surface.
SAMI Bitumen Technologies’ is well known for its technical excellence and expertise in delivering innovative road surfacing products and additives.
Prime and I-Brid
The SAMIBioPrime and SAMIfalt I-Brid solutions represent yet another advancement in solutions available to industry.
SAMIBioPrime is an environmentally-friendly, petroleum solvent-free bitumen emulsion, capable of penetrating all bound and unbound compacted base courses. The SAMIfalt I-Brid is a high-performance hybrid modified binder that excels in resisting rutting and fatigue, making it ideal for areas with heavy truck traffic.
SAMIBioPrime surpasses other primers, saving time and increasing efficiency by allowing the subsequent layers of spray seal or asphalt to be applied within one hour, compared to the standard 24 hours or three days required by other emulsions or cutbacks.
It’s one of the key reasons SAMI’s solutions stood out, Kumar says.
“Rather than using conventional methods, that could’ve taken months and cause inconvenience, we learned that we could do it in five nights and have an equal or better outcome,” he says.
The product not only ensure a fast-penetrating prime coat but also promote a greener approach to construction by being nearly carbon-neutral and containing no volatile organic compounds.
Professor Filippo Giustozzi, who was involved in the initial research and testing of both products, says they represent significant improvements in the performance and sustainability capabilities of bitumen additives. Adding that these products optimise what’s possible under Australia’s strict material innovation regulations in transport.
“The challenge was that in Victoria, the climate can range from very cold winters to very hot summers. There wasn’t a single product that can tackle both the performance at low temperature and high temperature,” he says. “The idea of the hybrid is to combine the best of these two worlds and create a single product that can offer what the elastomers do, and can at the same time offer the performance properties provided by plastomers.”
SAMIBioPrime is also a petroleum solvent-free bitumen emulsion which offers a safer user experience and eliminates the risk of explosion associated with other cutbacks.
Creating a universally compatible solution was a significant challenge. But as Giustozzi explains, these products were developed using existing knowledge and trials around elastomer and plastomer performance.
“You can guarantee the maximum resistance to cracking when it’s very cold, but at the same time, the product doesn’t soften when it’s very hot. That’s the essence of a hybrid,” he says.
Created and developed locally, both products have been designed and curated to cater for the unique challenges of Australian projects, while also supporting local industry and innovation.
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Achieving key objectives
With SAMI providing both the SAMIBioPrime and SAMIfalt I-Brid, and Alex Fraser producing the asphalt, the next step was locking in an experienced asphalt laying service provider.
RABS Group, one of the leading asphalt laying and road profiling companies in the industry was selected, based on its strong track record in delivering complex projects and works for Hobsons Bay City Council.
Braeden Cairney, Operations Manager – RABS Group says the company was quickly impressed with the performance capabilities of both SAMIBioPrime and SAMIfalt I-Brid.
“We were in touch with Filippo [Giustozzi], who got us in touch with Brad Richards from SAMI. That was when we got the lowdown on the hybrid solutions and what they could provide,” he says.
Brad Richards, State Manager Southern Region – SAMI Bitumen Technologies says that while the benefits are obvious, aligning product use with the right application can be a challenge.
That is, with products that aren’t as versatile as SAMIBioPrime and SAMIfalt I-Brid.
“It’s rare to have exceptional rut resistance and at the same time very good crack resistance,” he says. “Never before have the two been as good, in the same binder.
“SAMI prides itself on its innovation and new technologies, and it’s these aspects that solidify SAMI’s place in the market as one of the leaders in the industry,” Richards adds.
For Cairney and the RABS team, the biggest box ticked was the time required for curing.
“A standard prime can take anywhere from 24 to 48 hours to cure up,” he says. “It’s a far cry to have something that can break down as quickly as 20 minutes, to an hour and a half, depending on the temperatures.
“They were products that we were really excited to give a go, because we’re always pushing for the use of new products that the industry could benefit from.”
It wasn’t long after initial trial runs that the entirety of the RABS team was onboard with the use of both additives, reflecting the ease of placement required for the SAMIfalt I-Brid asphalt – a common theme among many of SAMI’s PMB (polymer modified bitumen) binder asphalt products.
“Crews are always hesitant to trial a new mix, but as soon as we got that first load down, they said, ‘This is fantastic’. There was no smell difference. There was no layability difference. It just felt like a normal mix to them, which is exactly what you want,” Cairney says.
“We know performance is better after the fact, but for them to think it’s the same as a conventional mix while they’re laying, that’s super critical.”
Project outcomes
Works on the project concluded in February 2024. The following months have acted as additional endorsement for the application of SAMIBioPrime and SAMIfalt I-Brid.
Importantly, the project also delivered several long-term benefits for the community. Not only in reducing potential disruptions during delivery, but also in laying the groundwork for more sustainable, local projects in the region.
These works have also highlighted the potential for high quality outcomes that can arise from collaboration between industry innovators.
Cairney says that without participation from all four project stakeholders, the works would have been significantly more difficult.
“It was a high-pressure job, but for it to go as well as it did, I credit everyone who was involved. From Hobsons Bay, to SAMI, to Alex Fraser and our business,” he says. “Everyone just worked cohesively and well together, and I’m super proud of the result.”
The project has been such a success that it’s won the 2025 AfPA (Australian Flexible Pavement Association) Industry Award,
for ‘Outstanding Project Less Than
$10 Million’.
Richards says its recognition like this that will cement the achievements reached on the project for years to come.
“It’s been a great recognition of all the hard work and teamwork that’s been put in, because this has been a massive collaboration,” he says.
“It’s clear that our clients and partners value quality, and that they’re looking for something outside of the box and sustainable. [They’re looking] for additives like these, that not only constitute the sustainable components in the product itself, but also support more durable – and therefore sustainable roads.”
Speaking to future collaboration, Richards says SAMI is excited to continue working with Hobsons Bay City Council to deliver favourable project outcomes. He adds that this extends to the other project partners, many of whom SAMI shares a long history with.
“Due to the success of this project and the road looking so good more than a year on, we’ve done another project using the same product in a different area for Hobsons Bay City Council. It just goes to show the confidence that they have in this technology,” he says.
This article was originally published in the September edition of our magazine. To read the magazine, click here.
