SAMI Bitumen Technologies, John Holland and State Asphalts NSW are combining their expertise as par of the development of an advanced water recycling centre. We speak to representatives from all three on how this project could be used as the new standard for sustainable material use.
As providers of different services, one important notion unites John Holland, SAMI Bitumen Technologies, State Asphalts NSW and Sydney Water. As well as sharing a desire to contribute to the growth of sustainable markets, each organisation has taken action, realising that words aren’t nearly strong enough to turn the tide. A recent trial incorporating biogenic materials has exemplified this action, while also clearing the way for more organisations across the sector to embrace sustainable alternatives.
START OF SOMETHING SPECIAL
More than 12 months ago, John Holland won a tender to deliver the Upper South Creek Advanced Water Recycling Centre and 40 kilometres of associated pipelines for Sydney Water.
This represents a significant project that, when complete, will contribute to future water demand in one of the county’s fastest growing regions.
As part of these works, John Holland was tasked with delivering the centre itself, along with a network of under and overground pipelines.
John Holland’s Mark Trethewy, Sustainability Manager, Upper South Creek – Infrastructure Projects says the first step was establishing strong relationships with material suppliers and designers.
“We started off by partnering with State Asphalts as we wanted to build a temporary construction compound of substantial size,” he says. “We wanted to have a series of internal access roads to construct as part of the asset. We saw an opportunity and went out to market.”
One such suitor was SAMI Bitumen Technologies, one of Australia’s largest providers of bitumen in Australia.
SAMI Bitumen Technologies General Manager Sebastien Chatard says the company’s efforts in the sustainability space is developing a number of environmentally friendly alternatives, such as its SAMIGreen products.
“Last year, we successfully introduced the SAMIGreen range to the market after extensive research and development of the product. Drawing from the valuable experience of our parent company in Europe, we created a high-quality range. Our efforts were recognised when we won the AfPA (Australian Flexible Pavement Association) innovation award in one of the states,” Chatard says.
“We then proceeded to present the SAMIGreen range to the market, and it received positive feedback from the sustainability managers at John Holland. We engaged in multiple meetings and presentations to further discuss the product’s potential.”
SAMI Bitumen Technologies reached an agreement to use its SAMIGreen A15E as a polymer modified binder for SMA mixture as part of John Holland’s works, allowing SAMI to demonstrate the effectiveness and benefits of SAMIGreen in realworld applications.
SAMI’s products, existing relationships, as well as its sustainability vision, all contributed to the company being selected as a key material supplier throughout the duration of the trial. “
Sustainability lies at the heart of SAMI Bitumen Technologies, and our R&D department is dedicated to developing solutions and products that offer sustainable advantages,” Chatard says.
Trethewy says the satisfaction of Sydney Water’s sustainability requirements were of upmost importance to the client. These represent high standards that are shared between the two companies.
“Sydney Water has a very strong 2030 and 2040 Net Zero pathway. We’re very cognizant of the fact that the only way we have to achieve that net zero pathway is supporting the sustainable supply chain,” he says.
“This is an operational facility that the client would be using for the next 50 years, while also supporting the works that we’ll be doing over the next five years. That’s why we needed a product that could have a longer lifetime and could be replaced with a similar product if needed.
“It was paramount that we find a material that could limit our carbon footprint, find a solution for problem waste streams in the market, and then provide equal or better performance to raw materials.”
TRIAL AND ERROR
The main objective of the trial was to identify a solution that offers reduced carbon footprint while maintaining or even improving the technical properties in the field.
In this trial, a 35-millimetre layer of SMA10 mixture, made with SAMI Bitumen Technologies’ bio-based polymer modified binder SAMIGreen A15E, was applied on the base course. State Asphalt, the subcontractor for the project, produced and laid the asphalt.
In addition to SAMIGreen, the SMA asphalt produced by State Asphalts incorporated recycled cellulose fibres called PAK-PAKE. PAK-PAVE fibres were developed by State Asphalts using postconsumer coffee cups. In addition to the trial mixture, a 45-millimetre layer of conventional AC14 with C450 binder was laid as a reference.
“We wanted to play with the mix and make it thinner, to really get aggressive on that carbon reduction, so there was some back and forth between my team and State Asphalt’s,” Trethewy says. “John Kypreos and the rest of the State Asphalts NSW team were fantastic working with us and SAMI. We loved working with both and the partnership is really strong. It helped to simplify many aspects of the process.
“Working with both helped to streamline the process. They had the right technical specialists on the ground, having a look at the ground conditions and site inspections and then feeding that back to the project team, ensuring that we could get the best result possible.”
The trial allowed for a reduction of one centimetre in thickness and a lower carbon footprint due to the use of the SMA mix and polymer modified biobased binder.
John Kypreos, State Asphalts NSW Director says the project highlighted the desire across the market for further development of a sustainable materials supply chain. A desire that he says must be satisfied if Australia is to improve its trajectory towards national netzero targets.
“We have good natural resources and a strong energy market, but the problem is that our industry is carbon intensive,” Kypreos says. “That’s where SAMIGreen fits in, using a biogenic material to lower the carbon footprint of the binder.
“We’ve got a great relationship with SAMI, so we were able to do a lot of research and development in house. We did our trials and they did theirs, then we’d come back together to share the results. In many ways we’re lucky, we have a recycling yard that’s a nominated area where we’re able to test a lot of these materials. That’s off the back of our work with the Australian Flexible Pavement Association.”
“This trial has provided us with an opportunity to accelerate progress towards these future targets and bring them into the present. It serves as a reminder that with determination and innovation, we can make significant strides towards a sustainable future,” Chatard says.
“The future for projects using sustainable materials looks promising. As the importance of environmental sustainability continues to grow, there is increasing demand for sustainable solutions in various industries, including construction and infrastructure.
“SUSTAINABILITY LIES AT THE HEART OF SAMI BITUMEN TECHNOLOGIES, AND OUR R&D DEPARTMENT IS DEDICATED TO DEVELOPING SOLUTIONS AND PRODUCTS THAT OFFER SUSTAINABLE ADVANTAGES.”
TRIAL OUTCOMES
The laboratory performance of the asphalt was of a high quality, demonstrating excellent resistance to fatigue and rutting. The carbon footprint of the binder was more than 50 per cent less than the carbon footprint of its corresponding grade and with the required technical properties.
Trethewy says John Holland, as well as the client, have been impressed by the trial outcomes.
“The State Asphalt team, along with SAMI, worked really close together, always making sure that there was an open line of communication. We were all focused on making sure that we could have a very robust final case study and report that would be viable for the industry in a potentially permanent and long-term scope,” he says. So much so, that Trethewy says this trial will act as inspiration for future works.
“When I look back on the previous five years as a Sustainability Manager, the perception and appetite for sustainable materials has massively changed. There’s now more opportunities and ideas that we can take on,” Trethewy says.
John Kypreos also sees this project as a turning point for the sector, explaining that there’s no reason why sustainable materials shouldn’t be prioritised for use in infrastructure projects of all sizes.
“I’m extremely proud of the team,” he says. “At the end of the day, we showed that different techniques are applicable, especially when using waste and a low carbon material. I think we’re going to see a lot more of this kind of research coming out and those outcomes coming to large infrastructure builds.
“It’s just a matter of continually pushing the boundaries of what we think is possible.”