On the road to 2045: Carbon-neutral asphalt

There are 8 000 km of paved roads cross Sweden that require constant maintenance. Every year around 7.5 million tons of asphalt are rolled out – a number that greatly contributes to carbon emissions, from its production to the finished coating. In other words: an opportunity for change.

While completely climate-neutral asphalt might sound unrealistic, Skanska Sweden has developed a new recipe of asphalt that has just been laid out on road 620 between Ludvika and Björsjö. Meet MJOG 16 V6000, probably the first climate-neutral asphalt mass in the world.

While the road to net-neutrality might seem long, the progress of carbon neutral asphalt, MJOG 16 V6000 is a great step along the way. The real breakthrough? A bio-derived binder. In the asphalt, bitumen, which is extracted from fossil crude oil, is partly replaced by a bio-derived binder. Since asphalt is 100 percent recyclable, the carbon dioxide that is absorbed and bound in the bio-derived binder will be stored for a long time, versus being released into the atmosphere. This way, the smaller amount of carbon dioxide emissions that remain from the production stage can be balanced, and climate neutrality is achieved.

Reducing emissions in three steps

In order for asphalt to have the lowest possible climate impact at the production stage, three important steps are required: the burner in the asphalt plant must be powered by renewable fuel (Skanska is gradually converting its more than 25 Swedish asphalt plants to firing with renewable fuel), the proportion of recycled asphalt in the new asphalt must be high, and parts of the binder bitumen are replaced by a bio-derived binder. With these measures, the climate footprint can be significantly reduced - all the way down to net zero emissions.

Paving the road ahead

One might wonder, if a climate-neutral asphalt is available, is it just to go ahead and roll it out on all new roads? Unfortunately, we still have a way to go. There are hundreds of different asphalt recipes depending on the climate and vegetation in the area, as well as what kind of traffic is expected to drive on the road. This bio-derived binder has properties that work well on the low-traffic, forest-clad roads around Ludvika, whereas a highway or residential street would require something different. Nonetheless, the development of MJOG 16 V6000 recognizes a milestone: the road towards a climate-friendly road on a larger scale is indeed possible to pave.