I-Brid on show -

The demonstration was performed at night, courtesy of SAMI

Sami Bitumen technologies and RMIT have worked together with the department of transport Victoria to place SAMIfalt I-Brid, a newly developed hybrid binder with outstanding performance benefits, in a demonstration project in Bendigo, Victoria.

In June 2020, Sami Bitumen Technology’s innovative high-performance hybrid binder SAMIfalt I-Brid was used on the apron area at Bundaberg Airport in Queensland.

Six months later I-Brid is being trialled in different conditions, a few hours outside of Melbourne. The demonstration project was undertaken at Kangaroo Flat – Calder Highway, near Bendigo, in Victoria.

SAMI Bitumen Technologies and its partners, the Royal Melbourne Institute of Technology (RMIT University) and Centre State Asphalting (CSA) paved a section of I-Brid asphalt next to a section of standard polymer-modified asphalt in order to compare results under the local traffic and weather conditions.

The demonstration trial was done in collaboration with the Regional Roads Victoria, part of the Victorian Department of Transport which was keen to observe the application of an asphalt modified with an innovative set of hybrid polymers and assess its performance.

SAMI Bitumen Technologies supplied approximately 25 tonnes of the SAMIfalt I-Brid to CSA from its manufacturing facilities at Laverton, Victoria.

The total quantity of I-Brid asphalt paved was 540 tonnes, following the mix production at CSA’s asphalt plant in Maryborough, Central Victoria. After manufacturing, the mix was transported one hour to the site at Kangaroo Flat and paved.

Roads & Infrastructure catches up with the team to learn more about I-Brid and the Victorian demonstration project.

SAMIfalt I-Brid was developed over about 18 months by a team of SAMI binder specialists in partnership with RMIT. I-Brid is a combination of innovative plastomeric and elastomeric polymers, which results in a binder that has both high deformation and fatigue resistance over a wide spectrum of traffic loading and ambient conditions, including at very high temperatures.

The binder is formulated with four key polymeric pillars, a highly-compatible thermoplastic elastomer, a polyolefin, an unsaturated thermoplastic elastomer and a homopolymer. These elements allow I-Brid to exhibit high stiffness at high in-service temperatures and flexibility at medium and low temperatures.

One of the four polymeric pillars is also responsible for imparting improved compactability to mixes when laid at low ambient temperatures.

Filippo Giustozzi, Associate Professor at RMIT, was instrumental in the development of the I-Brid binder, working closely with SAMI Bitumen Technologies.

He says that following the application of I-Brid at Bundaberg Airport, the team approached the Victorian Department of Transport (DoT VIC), to float the idea of a demonstration project in Victoria.

“We wanted to show them that there is an alternative to some of the binders they currently use, so we set up a trial to test I-Brid against a standard modified product,” Giustozzi says.

“DoT VIC was very keen to trial the product as they had already heard about it from various presentations and a recent report we shared, so they were happy to give it a go.”

John Esnouf, Principal Engineer at VDOT was instrumental in helping to set up the demonstration project at Bendigo being interested to observe how I-Brid performs in the field. The demonstration was performed at night.

“We’re always keen to encourage innovation of all kinds and we’ve been watching the development of I-Brid for some time with keen interest,” Esnouf says.

“We were pleased to be able to facilitate a field trial for this in Bendigo and are now looking forward to observing and monitoring its performance.”

The asphalt mixes in the demonstration project were laid one after the other on different night shifts in Bendigo. While it is still early days, the initial demonstration went well and the pavement will now be monitored by the team over the coming months and next year.

“The asphalt laying in the demonstration project was successful, and there were a lot of interested parties that came out amongst them being the VicRoads regional unit. The product was placed without any issues, we measured temperature at each stage making sure that the paving stage is undertaken in the correct way. The mix compactability was excellent and there was nothing visibly wrong with the finished surface,” Giustozzi says.

Esnouf was also pleased with how the demonstration project turned out.

“The trial went very well. The asphalt that included I-Brid was easy to place and compact. These demonstrations prove that a product can be used in a real-life environment because it must be able to be transported, placed and compacted well and field demonstrations help to prove that,” he says.

For performance monitoring the team took samples of the I-Brid binder from SAMI Bitumen Technologies Laverton plant, asphalt mix from the CSA plant after production and from the paver as the mix was being laid.

“We want to better understand and monitor the long term performance of both pavements so we are going to undertake measurements in order to monitor roughness, rutting and visible deformation over one to two years,” Giustozzi says.

“We want to create confidence within DoT VIC so that the product would be used in the future. We had several meetings with them to ask what they want to see, and we want to demonstrate that I-Brid can fully meet their expectations in terms of performance over the long term.”

Giustozzi says I-Brid can even be paved in the cooler-seasons, or when the plant is a long way from the site, because its properties facilitate compaction at lower ambient temperatures.

Following the Victorian demonstration project, the team is in conversation with Transport for New South Wales and Main Roads WA for further I-Brid demonstrations projects in the near future.

This story originally appeared in the May edition of our magazine. To read the magazine, click here.