Sustainability efforts take off at Arlanda
By using Nypol RE, a polymer-modified binder with a biogenic component, it is possible to reduce the climate impact while extending the technical lifespan of the asphalt. This was the reason behind the choice of coating when Skanska recently carried out work at Stockholm Arlanda Airport.
Given the weight and speed of an aircraft, extra stringent requirements are placed on load-bearing capacity, friction and surface properties for paving work at an airport. Additionally, the asphalt must be resistant to jet fuel and the chemicals needed to prevent ice formation.
These were the conditions when the construction company Skanska, on behalf of Swedavia, was set to replace approximately 20,000 m2 of wearing course on one of the taxiways used for aircraft ground movement between the runways and the terminal area at the end of May.
Before starting the work, Skanska conducted tests with the polymer-modified bitumen, Nypol RE, which would be used as the wearing course. The purpose of the tests was to evaluate and compare functional properties with a reference made of conventional PMB.
"An important property of all wearing course coatings at Arlanda, for example, is that they must be resistant to potassium formate, which is used as a runway de-icing agent. Our tests show that Nypol RE is at least as good as the reference binder," notes Skanska’s bitumen and asphalt specialist Kenneth Olsson.
Nypol RE is a relatively new product containing a biogenic component specifically formulated to compensate for the addition of the polymer. This includes the footprint of the material itself, the transportation, and the actual polymer modification process. As a result, one tonne of Nypol RE has the same carbon footprint as one tonne of unmodified standard paving grade bitumen but with all the performance advantages of a polymer-modified bitumen.
It is an option that aligns perfectly with both Skanska's and Swedavia's efforts to reduce the climate impact from asphalt coatings according to their ambitious climate goals.
"We have used Nypol RE since 2021 on the heavily trafficked Stocholmsvägen in Malmö, and it therefore feels reassuring for us to apply it to one of Arlanda's taxiways as well," confirms Kenneth Olsson.
The new surface consists of two layers. Half of the surface is a 40 mm ABTs16 Nypol 76-28, while the remaining part consists of a 40 mm ABTs16 Nypol RE 73.
"We started by milling up the old polymer-modified wearing course, which will be recycled into new asphalt layers. Then we used a Shuttle Buggy for the actual paving to homogenise the mix after transport from the asphalt plant," explains Kenneth, who is very satisfied with the collaboration with Swedavia.
"They deserve praise for wanting to test future asphalt surfacing with lower climate impact. We all in the industry have a tough journey ahead to achieve our sustainability goals, and this project is undoubtedly moving in the right direction."
This view is confirmed by Sandra Säfström, environmental specialist at Swedavia.
"We need to test alternatives with reduced climate impact in order to achieve our environmental ambitions in the long run while maintaining today's high standards of functionality and aviation safety," she says.
In this context, it is crucial that product development continues through some form of collaboration and shared vision among all involved parties. This aligns well with Swedavia's value of being innovative.
"Innovation is close to our hearts, and we appreciate this type of initiative. Our vision for 2030 includes a zero-waste goal and a focus on circular business models, which Nypol RE can contribute to through the expected increased maintenance intervals," Sandra clarifies.
She also points out that a product with lower climate impact that contributes to extended maintenance intervals helps Swedavia achieve the goal of net-zero greenhouse gas emissions by 2040.
In addition to the ambitious goals for reduced climate impact that Swedavia is working towards, they have also joined Fossil Free Sweden's roadmap for fossil-free competitiveness: the Building and Construction sector.
"Nynas' initiative with Nypol RE aligns with several of the commitments described in the roadmap that participating actors should adhere to. This applies especially to the obligation to collaborate across the entire value chain to ensure effective climate work in line with the roadmap's goals," concludes Sandra.
