New, quieter asphalt road surfaces thanks to the use of recycled rubber granules
- New road surfaces with recycled rubber reduce traffic noise by between 2 and 5 decibels
- The PERSEUS project validates more sustainable asphalt mixes with a lower noise impact on roads
Madrid, 9 January 2026 - The PERSEUS project, which ended last June, succeeded in developing new asphalt mixes that significantly reduce rolling noise by incorporating rubber granules from recycled end-of-life tyres (ELTs).
- This material is used as a partial substitute for aggregates, and provides a more sustainable solution without compromising the durability of the road surface.
- The project consortium – made up of CAMPEZO, ASFALTIA, MOEVE, SIGNUS and TECNALIA research and technological development centre – worked in a coordinated manner on developing and validating these mixtures both in the laboratory and on a real test section, installed on the AP-8 ‘Southern Metropolitan Bypass’.
- This section was provided by the Provincial Council of Bizkaia through the Bizkaia Connected Corridor (BCC) initiative.
Technical challenge: larger rubber particles in higher proportions
The project's main challenge consisted of replacing part of the aggregates with much larger rubber particles than those normally used, and to do so in high doses with the aim of developing poroelastic road surfaces.
- To achieve this, it was necessary to design new mix formulations, select a specific binder and carry out a detailed study of the durability of the mix to ensure cohesion between the rubber and the binder.
- This work allowed us to produce two types of sustainable, sound-reducing road surfaces suitable for use on roads, capable of reducing the noise generated by traffic and, therefore, improving the sound environment for the population.
Main results
- Incorporation of recycled rubber: PERSEUS mixes include rubber granules with particle sizes between 0.8 and 8 mm. The percentage of aggregate replaced is between 4% and 5%, which is equivalent to about five end-of-life passenger car tyres for every linear metre of mix laid. This figure is significantly higher than the 0.5% - 2% usually used on roads.
- Lower temperature and lower emissions: the use of a low-temperature binder has led to a reduction of around 20°C in the manufacturing and laying temperature, which means a reduction of approximately 3 kg CO₂ equivalent per tonne of mix.
- Noise reduction: the new mixes provide an improvement in noise levels of between 2 and 5 dB. A reduction of 5 dB is equivalent to a 75% reduction in traffic on a road, according to the CNOSSOS European benchmark.