PROJECT DESCRIPTION
BACKGROUND
Over recent years, a dramatic increase in traffic has occurred in Europe, which has led to an increase in noise pollution. Noise pollution significantly affects the quality of life of inhabitants in urban areas, through direct and indirect effects on health. Road noise plays an important role in this issue, and is a predominant source of noise with vehicle speeds higher than about 50 km/h. For this reason, one of the most effective measures to reduce noise pollution in urban environments with speeds over 40 km/h is to reduce the noise emission from road surfaces.
OBJECTIVES
LIFE-SOUNDLESS aimed to demonstrate the effectiveness of innovative noise-reducing asphalt mixes, used in SMA (Stone Mastic Asphalt)-like thin layers using waste materials, to mitigate noise pollution. The project would also encourage public bodies to integrate environmental factors into their calls for tender in street construction. Hence, LIFE-SOUNDLESS had been conceived as an effective solution to shape a sustainable and healthy future for urban areas. By recycling and re-using waste from different industries, the project would also help implement waste management objectives set out in the ‘Roadmap for a Resource-Efficient Europe’ and the 7th Environment Action Programme.
General objectives were to:
- Reduce noise pollution from roads in densely-populated areas by means of innovative noise-reducing asphalt mixes with the same durability as conventional mixtures;
- Improve the environment in urban areas by implementing eco-friendly, long-life and cost-effective road surfaces;
- Validate a feasibility initiative for the re-use of rubber, plastic and fibre waste, and to facilitate a new and wider market for these wastes;
- Improve knowledge and supply data for the development of recommendations on the use of low noise surfaces, and therefore to contribute to the adoption of European specifications for noise-reducing asphalt roads; and
- Assess the evolution of the acoustic performance of these types of mixes in Mediterranean countries, which are subjected to atmospheric conditions different from those of the northern European countries where experience in their use is highest.
RESULTS
The LIFE SOUNDLESS project team developed and demonstrated the efficiency of new asphalt mixtures, made using different types of recycled industrial plastic waste. These were manufactured to construct demonstration stretches of roads in two pilot sites in Spain, whose performance was assessed over 24 months during five monitoring campaigns.
The new asphalts achieved their objective of reducing road noise levels in densely-populated areas. They reduced noise by 6dB compared to the original asphalts they replaced, and by 3dB compared to the reference asphalt mixture AC 16 surf. Furthermore, the durability of the developed asphalt mixtures is above the values set in the literature.
The experience gained through the project implementation was used to draft a proposal for the development of a protocol, at a national level, for the assessment of noise in different types of pavement. This included draft technical recommendations for the design, manufacture and laying of noise-reducing SMA (stone mastic asphalt) mixtures with the addition of by-products or wastes. The project team’s protocol could lead to a Spanish normative standard regulating noise-reducing pavements.
The project team have laid the ground for the potential replication of actions in similar sites in southern Spain. Reports of the studies and measurements done in these proposed sites have been submitted to the relevant municipalities.
The project team’s findings have been widely disseminated, via various media.
The environmental and social benefits of the project’s new road surfaces are potentially very high, considering that the impacts of environmental noise on people is a major health concern in Europe.
Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).
