With demand for more sustainability in asphalt paving practices, Australian departments of transportation are exploring asphalt rejuvenators that can help increase the amount of reclaimed asphalt pavement (RAP) they can use in their mixes. Using more than 25% RAP in a mix requires the use of an effective rejuvenator or recycling agent to restore the functional properties of the aged bitumen in the mix. Exploring the possibilities for reducing virgin binder and fresh aggregate requirements, Brisbane City used Sripath’s ReLIXER® in a high-RAP mix trial. The story was covered in the October 2022 issue of AsphaltPro. 

 

Leading up to the roadway trial, mix design research was conducted by the Royal Melbourne Institute of Technology (RMIT). The asphalt rejuvenator is designed to improve workability and compactability of the mix while supporting performance specifications and durability. Initial testing supported these claims. “ReLIXER is very effective in restoring the functional properties of the aged bitumen in mixes using recycled asphalt pavement (RAP) material,” explained Dr. Filippo Giustozzi, Associate Professor, RMIT. “It is highly dosage efficient and provides long-term rejuvenation for sustainable infrastructure projects.”  

 

The roadway trial, which was conducted in June 2022 and implemented by asphalt pavement contractor Fulton Hogan, included an asphalt mix containing a multi-grade binder (M1000), 40% RAP, 3.1% binder, aggregate, and 3.24% ReLIXER. The mix performance was compared to a control mix of M1000 and 15% RAP. The trial results indicated that ReLIXER effectively rejuvenated the aged binder, reduced the need for virgin bitumen and aggregate, and helped reduce mix costs. “We really enjoyed working with Brisbane City Council, Fulton Hogan and RMIT in preparation for and during this trial,” said Ravi Rajagopalan, General Manager, Sripath Asia-Pac.  

 

In addition to helping contractors incorporate higher amounts of RAP in their mixes, ReLIXER supports sustainability efforts as an environmentally friendly product. The asphalt rejuvenator is specially formulated from bio-based oils sourced from crops that do not impact food resources. “ReLIXER helps reduce the carbon footprint and greenhouse gas emissions,” Rajagopalan explained. “ReLIXER has been tested, vetted and adopted by experts around the world, now also in Australia.” 

 

Read the full article for more trial details and insights into additional ReLIXER evaluations conducted in Australia.