In the PERSUADE project, a consortium of twelve partners is working on the development of the poro-elastic road surface (PERS). The aim is to obtain a road surface which is extremely noise reducing (up to 12 dB(A) with respect to DAC), reasonably durable, safe for the traffic, environmental friendly and affordable. A poro-elastic road surface contains a large percentage of rubber (recycled tyre granules or fibers), (possibly) mineral constituents (stone aggregates and/or sand), glued together with a polymer glue (usually PUR). Several application modes will be tested (prefabricated mats, on site construction, the Rollpave concept and sets with a PERS layer on top.
The project aims at developing a durable, cost-effective Poroelastic Road Surface (PERS) using used tyres, which would at the same time benefit the environment by not only significantly contributing to abating traffic noise and vibrations but also helping to solve the problem of over three million tons of used tyres having to be dumped or burned every year in the twenty-seven Member States with the consequence on ground and air pollution. It is anticipated that an advanced optimization of the poroelastic rubber compound could lead also to a decrease of rolling resistance for the vehicles rolling on such a pavement and, as a result, could contribute to reducing CO2 and other emissions.
Indeed, end-of-life tyres are a disposal problem regarding the large volumes produced every year. Tyre shreds are primarily produced to reduce the transportation volumes of end-of-life tyres after collection. Within the European Union, there is a ban on land filling tyre material in order to reduce the total land filling volumes and to encourage recycling measures [Directives 1999/31/EC & 2003/33/EC]. Until recently the main disposal option has been energy recovery in industrial processes. However, legislation acts has recently been taken in the European Union to encourage recycling and recovery of end-of-life-tyres and re-use of tyre materials in construction works is listed as one disposal option. Tyre shreds possess interesting technical properties that could be beneficially used in civil engineering applications. Some characteristic properties of tyre shred materials are the low density, high elasticity, low stiffness, high drainage capacity, high thermal insulation capacity and intrinsic wear resistance. These properties open up possibilities for utilisation of the material in an innovative manner.
In this project, one will take advantage of existing experience in Sweden and in Japan. The former country is represented in the Consortium while the latter will be represented in an External Reference Group (ERG). Five countries will host the experimental sites and apply different variants of mixes and construction methods among which a newly invented Dutch method, namely the “Rollpave” system. The countries are: Belgium, Slovenia, Denmark, Sweden and Poland. This will allow for the influences of climate and traffic differences to be tested. Regarding traffic, some countries will experiment PERS in a city street with slow, light traffic while others will test it on a highway with fast, heavy traffic. Already the Belgian (Walloon) road administration have expressed willingness to offer a test site, the Road Directorate in Denmark have expressed interest and there is a certain interest in the city of Stockholm to host a test site as a follow-up of previous experiments.
The project will also analyze the cost effectiveness and the global, possibly positive impact on CO2 emissions and greenhouse gases (GHG) in general of that new technology. Life cycle assessment will also be performed.