New rubberised asphalt additive promises better, safer roads

The EU-backed, Silent Rubber Pave team has developed an innovative asphalt additive, RARx that incorporates a large amount of crumb rubber powder from end-of-life tyres (ELTs). The use of crumb rubber from ELTs in asphalt mixtures is expected to overcome the pavement industry’s challenges: the novel additive can “give new life to ELTs, lead to more technically-sound roads and cost-efficient road projects, and ultimately make the circular economy in the pavement industry a reality.”

About 60% of its composition, the RARx powder is pretreated with bitumen and other mineral additives to increase its performance grading, resilience and recovery properties. RARx can be added to any type of hot mix asphalt for replacing part of the bitumen at different proportions.

Its technical features are claimed to be an improvement over current solutions in the asphalt and road construction market, and recent life-cycle cost analysis also demonstrated that RARx enables the production and installation of longer-lasting asphalt mixes that use much more efficient construction systems. 

RARx optimises asphalt packages by up to 50%, with considerable savings on site, while employing RARx in mixtures can save up to 46% in costs, with savings of up to EUR 50,000 (USD 58,700) per kilometre of road built. 

“In this sense, introducing RARx to the markets is complex, since it requires a process of regulatory study and adaptation to its own standards to convert it into a product that can be used regularly,” commented Maria de la O Terciado, coordinator of the project. “But RARx will enable plants to manufacture high-performance asphalt mixtures for small or large works without incurring extra energy costs.”

Silent Rubber Pave is currently seeking the necessary approvals to commercialise RARx in Spain and other European countries, followed by Asia and the US. This has led to the creation of the joint venture with CIRTEC, a Spanish company that is the driving force behind RARx in the market. The product is currently being used on the streets of Madrid.