Reducing traffic noise with “silent” asphalts made with recycled materials: The European Project Life-Nereide

Traffic noise afflicts 125 million people all over Europe. A solution comes from the innovative European Project Life-Nereide. It will test noise reduction in some Italian towns thanks to asphalts made with the addition of rubber recycled from End-of-Life Tyres and “recycled” asphalt. This topic will be discussed at Asphaltica today, the main Italian event dedicated to the asphalt chain.

In Europe 125 million people are daily exposed to excessive traffic noise and, for this reason, they risk suffering even serious health consequences - as repeatedly pointed out by the World’s Health Organization. Even if it is often underestimated, this problem is quite important.

Among the possible enforcement actions, one of the solutions that has the largest development potential due to technology maturity and the possibility of large-scale application, is the use of “sound-absorbing” asphalts, made with the addition of rubber powder from End-of-Life tyres to bitumen.

To test its characteristics and advantages, in September 2016 the Project Life Nereide started. Co-financed by the European Union, this project aims at optimising the acoustic benefits of road surfaces made with the addition of recycled rubber and asphalt millings, the material obtained by the recovery of old road surfaces and used in replacement of the commonly used virgin minerals.

Head of the project is the Department of Civil and Industrial Engineering of the University of Pisa, in collaboration with ARPAT (Regional Body for the Environmental Protection of Tuscany), the Belgian Research centre BRRC (Belgian Road Research Centre), the non-profit consortium company Ecopneus, the Institute of acoustics and sensoristics "Orso Mario Corbino" and Region Tuscany. 

The Project Nereide (acronym of: Noise Efficiently REduced by recycleD pavements) wants to bring benefits not only from the noise pollution point of view, but also with reference to the overall environmental impact and air pollution thanks to the creation of new pavements. Its objectives, the actions provided for, and the expected results will be explained today at the fair “Asphaltica” of the city of Verona during a meeting that will be held at 16:00 in the Forum Area. Asphaltica is the main event of the asphalt chain in Italy.

In the course of the project 5,250 metres of these new experimental road surfaces will be laid (5,200 m of low-noise emission surfaces in Tuscany and 50m of test surface in Belgium), also thanks to the use of 35-50% of recycled asphalt.

New methodologies of acoustic measurements will also be developed. These will allow greater reliability of monitoring results, helping and guiding the Public Administration and the contracting authorities in the choice of the new asphalts with improved performances. 

Thanks to this project, an effective improvement of the quality of life of the people is expected with reference to noise exposition, as the new surfaces will be made in urban areas where noise limits are exceeded and where a mitigation intervention has already been planned. 

Indeed, in Italy, especially in urban areas, the creation of barriers or insulating windows is often unfeasible or ineffective. The expected improvement of the quality of the perceived sound will be evaluated by the means of about 700 questionnaires that will be administered to the citizens. They will evaluate the psychoacoustic effects and the differences with the new surfaces with reference to the perceived noise and sleep disorders.