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.

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.