In a new product line, Nypol RE, the combination of Nynas in-depth bitumen knowledge, experience with polymer modification and the addition of a renewable material containing biogenic carbon provides an innovative tool for the road construction industry to reduce its climate impact.
Extending the useful life of a road has many benefits; less material is used over the lifetime of the road, fewer maintenance interventions are needed leading to fewer traffic interruptions. All of these benefits provide a positive sustainability contribution.
One established method to extend the useful life of asphalt is to use a polymer modified binder, but polymer modification comes with a carbon cost as the polymer has a relatively high carbon footprint. With the extension of the useful life this is often worth the added footprint.
But, what if you could achieve all the benefits without this additional carbon? This is the idea behind Nypol RE, polymer modified binders containing biogenic carbon.
During the photosynthesis process that takes place when plants grow, carbon dioxide is taken up from the atmosphere. When sustainably sourced biomass is made into products that are not burned, its embodied carbon is bound in the product and therefore helps address global warming. This means that the biogenic carbon in the product is counted as a negative emission.
Following an extensive amount of research into the performance, ageing and circularity of the Nypol RE products, they have been successfully used in asphalt pavements in Norway, Sweden and the UK.
One example from Sweden involves the construction group Skanska. They are working to reduce the climate impact from their asphalt products so they can achieve their climate-neutral goal by 2045. Last autumn one important step in this direction was taken when they installed a new pavement, with a total area of 35,000 m2, on a section of road with heavy traffic in Malmö in Southern Sweden. Nypol RE was used for some of this surface as the client wanted a solution with the smallest possible carbon footprint.
Before surfacing work started, Skanska conducted laboratory studies to assess and compare functional properties in the asphalt mixture made with Nypol RE with a reference using conventional PMB. “We were unable to identify any differences between the two types,” says Kenneth Olsson, Skanska’s asphalt specialist. The paving team could also confirm that the new binder flowed more freely when discharging compared to a regular PMB, and that the asphalt mixture exhibited good workability.
The use of biogenic material in the binder is also in line with leading construction materials group Breedon’s objective to continuously reduce the impact of their operations on people and the environment. This explains why they chose Nypol RE for a car park in Nottinghamshire, where the typical tight turning circles and heavy abrasion demanded a high performance asphalt.
“We are proud to be the first asphalt manufacturer and contractor in the UK to produce and lay an asphalt surface course using a polymer modified bitumen containing a biogenic component,” says Tony Wilson, Technical Manager GB of Breedon.
The properties of the asphalt and test results clearly demonstrate there is no difference in performance between Nypol RE 103, the PMB with biogenic material, and Nypol 103. The experiences from Nottinghamshire illustrate the importance of innovative development work and how Nynas, together with its customers, can support the sustainability ambitions of the road construction sector.
“This new binder is a major change for the industry, with the ability to now offer a PMB performing asphalt with a lower CO2 footprint, which will significantly reduce a pavement’s environmental impact,” Tony Wilson concludes.
As the examples from Sweden and the UK show, by working together our industry is able to take the important steps towards a future where the environmental impact of the road construction is minimised.