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SAMI: Proof of excellence

SAMIfloat represents the latest in high-float emulsion technology from SAMI Bitumen Technologies. Image: SAMI Bitumen Technologies.

Recent works by SAMI Bitumen Technologies have evaluated the use of its SAMIfloat high-float emulsion in a high-volume setting for the first time. SAMI and COLAS representatives delve into how the product exceeded expectations.

SAMI Bitumen Technologies is always pushing the envelope and never resting on its past successes when it comes to product development. 

This ethos results in each of its products being put through their paces during development, with multiple trials and tests evaluating any possible potential improvements. 

The company’s SAMIfloat spray sealing solution had already proven to be a more than effective alternative to conventional spray seals, following initial trials. So how do you build upon a product that has already proven to be effective? You push it even further.

SAMIfloat is a cationic high-float emulsion product, which creates a gel-like structure within the binder. This structure helps to create greater adhesion within the aggregate and prevent emulsion run-off and bleeding. 

This design allows SAMIfloat to be a more durable and better performing option for road sprayed seals, in part due to the product containing a thicker film. This prevents aggregate stripping, while also making it more resistant to oxidisation from exposure to the atmosphere.

Despite these impressive chemical properties and performance characteristics – and despite undergoing multiple internal trials – the product required to be proved on a project of significant volume. That is until a recent project at Glenn Innes. 

Situated in the New England region of New South Wales, Glenn Innes had already been the site of an initial trial for SAMIfloat, where 8000 litres of the product was applied over 12 months ago. 

After the successful trial of using SAMIfloat in a graded seal project for the Glen Innes Council in September 2022, Colas NSW placed an order for 300 tonnes of SAMIfloat to be used in the construction of approximately 140,000 square meters of graded seal in the Deepwater area of Glen Innes. The product was manufactured at both SAMI Camellia and Pinkenba production facilities. 

As Andrew Carter-Meggat, Operations Manager – COLAS explains, Glenn Innes once again presented the ideal circumstances for further evaluation of SAMIfloat. This time, on a much larger scale.

“When we first trialled SAMIfloat 12 months ago, it performed quite well and some of the characteristics of the product were better than anticipated. For our most recent project, we would be required to apply more than 300,000 litres of product over the course of seven days,” he says.

To complete the project, SAMI Bitumen Technologies produced the product one-to-two days in advance at its sites in Pinkenba, Brisbane and Camellia, Sydney.

The Glenn Innes project represented the first time that SAMIfloat has been applied in a large volume setting. Image: SAMI Bitumen Technologies.
The Glenn Innes project represented the first time that SAMIfloat has been applied in a large volume setting. Image: SAMI Bitumen Technologies.

Requirements from the Glenn Innes council increased the complexity of this project compared to the initial 8000 litre trial, as Carter-Meggat adds.

“When speaking with them, they had a few constraints around their works program. The purpose of the project was to basically seal their local road network. The council nominated two roads within their network, which came to a total of around 17 kilometres,” he says.

“We thought that SAMIfloat would be the best option for them in terms of delivery, since they wanted to deliver this project in the summer.”

There were still some unknowns around the product, such as how it would perform in differing conditions in such a large volume, as well as logistical factors such as manufacture and delivery.

“We had to work through some of our own constraints and come together as a team. We weren’t sure how the product was going to go in such a large volume. I mean, we only sprayed 8000 litres in the trials,” Carter-Meggat says.

“So those were some of the concerns that we had about the product, on top of the weather conditions.”

Phil Stevens, QLD State Manager – SAMI Bitumen Technologies, says both his company and COLAS worked closely to find solutions for these “unknowns”.

“In terms of the manufacturing side, we were initially concerned that the product may be difficult and slow to produce. SAMIfloat does contain ingredients which can be sensitive and tricky to manage, however we gained confidence in our ability to make this product quickly and at a high quality at the plant,” he says.

“The feedback from Colas NSW was very positive at site, and it appears the seal has performed as intended. This product is unique compared to similar products we produce for these types of projects, due to the way it holds up when sprayed and how it eliminated some of the issues normally encountered with other binders.”

Carter-Meggat says the larger project provided valuable experience for both himself and the rest of the team.

“With a new product like this, there’s always some surprises and learnings. Our team were a little unsure with how it was going to perform, how to place it, and what the differences were between this product and others they’ve used in the past. It was a big learning curve for everyone in the team,” he says.

“We had some weather come in and we received 25 millimetres of rain in one downpour. We thought that the product would re-emulsify. It didn’t, it stayed intact, which we were very surprised about.”


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Feedback has highlighted the effectiveness of the product, as well as the satisfaction of the council in terms of the product’s performance.

“The Glenn Innes Council has been very happy with it, and I believe surrounding councils are able to have a look at the end result, which has impressed them as well. I believe the success of this project will open new doors for other councils and their road network and infrastructure programs,” he says.

“It’ll assist these councils to seal their unsealed roads efficiently and sustainably. While it’s not carbon neutral, the carbon emission of total application is significantly lower than usual practices. SAMIfloat will take off more and more, once more councils are able to see how it actually works and how it’s performing over the next 12 months.”

The sustainability of SAMIfloat is a result of reducing the amount of heating required when compared to hot cutback binders, making it more environmentally friendly.

Spraying the binder at 70-80°C instead of 180-190°C, saved energy and costs, reducing safety and health risks, and providing environmental benefits. Eliminating the use of cutter in the binder can reduce costs and the risk of fire and explosion, also offering environmental benefits. 

“Omitting the use of cutter can also reduce the risk of flushing and tenderness in hot seasons. The residual binder, resembling a multigrade binder, has a high enough penetration value to resist cracking in low temperatures, and its softening point is high enough (due to polymer) to prevent flow or flushing in high temperatures,” Hamidreza Sahebzamani, Technical Services Manager says.

“Approximately 50,000 litres of kerosene were saved and not released into the environment in this project.”

Lee Whitehead, State Manager, NSW – COLAS, says sustainable alternatives such as SAMIfloat are the best way forward for the sector.

“To tackle climate change and biodiversity loss, COLAS is committed to a strategy based on a low carbon and biodiversity roadmap. The Group is implementing actions to reduce the carbon intensity of its direct emissions and is developing and promoting low carbon techniques and solutions,” he says.

“As a player in sustainable development, the Group takes into account the life cycle management of infrastructure, from its design to its recycling, in order to reduce its impact. With innovative solutions that add new functionalities to roads, COLAS is helping to build the infrastructure of the future to serve local communities.”

The project exemplified the high sustainable and performance characteristics of SAMIfloat. Image: SAMI Bitumen Technologies.
The project exemplified the high sustainable and performance characteristics of SAMIfloat. Image: SAMI Bitumen Technologies.

Carter-Meggat says that the performance characteristics of SAMIfloat will also help to increase the versatility of the spray sealing industry in Australia. 

“By utilising this product, we can extend our window for sealing. Traditionally, sealing in winter could be done, but it can be quite risky. As this product is a cold product, you can spray it in the winter and your risk factors are significantly less. It helps to increase our productivity for our teams, as well as the end client,” he says. “Now that we can have that extended window, we can build more relationships with more clients and provide certain packages for more local councils.”

Despite the high slope of the road, there was no runoff, no aggregate pick-up, no pin-holing, and the adhesion of the binder to aggregate was excellent. The road was also opened to traffic immediately after the compaction was completed. The project commenced on 11/12/2023 and was finished a week later. Stevens says the success of the project has elevated SAMIfloat as a premier option for quick, efficient spray seals, where longevity is also required.

“I attended the site to observe the works and how the binder was behaving,” he says. “It was apparent how important the SAMIfloat binder characteristics were in order for COLAS to achieve their productivity goal and ensure the seal would hold up as designed for the client,” he says.

“This is another product we can now proudly place in our catalogue with proven performance and can provide SAMI and COLAS a competitive advantage in the market.” 

This article was originally published in the March edition of our magazine. To read the magazine, click here.

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