Asphalt rubber paves the way for lower environmental impact
New life cycle assessment:
A new life cycle assessment shows that asphalt mixed with recycled tyre material can reduce the environmental impact when we build roads. Essentially, the rubber makes it possible to lay a thinner layer of asphalt, simultaneously increasing the surface’s service life.
A life cycle assessment studies the environmental impact throughout the product’s entire service life. The life cycle assessment which Ragn-Sells has commissioned together with Svensk Däckåtervinning and Norsk Dekkretur shows that the environmental impact from asphalt is less when recycled rubber from tyres is mixed into the asphalt compound. The test section with asphalt rubber that produced the greatest difference reduced the impact on the climate by 62 per cent compared with ordinary asphalt.
There are two principal explanations for this. One is that the rubber mixture allows the road builder to use a thinner layer of asphalt. In addition, the asphalt rubber lasts for longer than conventional asphalt, which is important when assessing the environmental impact throughout the entire life cycle.
Four sections of road were compared in the assessment, three with asphalt rubber in different layers and one with solely conventional asphalt. The table below shows differences in estimated service life, where REF stands for reference road with ordinary asphalt.
The key to lower environmental impact for asphalt is to reduce the use of fossil-based energy. Replacing bitumen with recycled tyre rubber as binder achieves precisely this, at the same time as increasing the surface’s service life.
Ragn-Sells is endeavouring to ensure that the re-use of worn out tyres makes as great a contribution as possible to reducing exploitation of virgin resources through a more resource-efficient cycle.