A Croatian project, part funded by the European Union's Competitiveness and Innovation Programme Eco-innovation initiative, is aiming to demonstrate that recycled vehicle tyres can be turned into an environmentally-useful product: sound reduction barriers that are installed alongside roads and railways.
The RUCONBAR (Rubberised concrete noise barriers) project is led by a team from the Faculty of Civil Engineering, University of Zagreb. The faculty developed the idea of the sound barriers through earlier projects, and has tested, proved and patented them. The barriers are made of “rubber concrete” – their noise-absorbing layer is a mixture of stone aggregate and 40% rubber granules recovered from car tyres. The RUCONBAR barriers are as effective as other concrete barriers for cutting noise levels, and are significantly more effective than wood or plastic barriers.
The main benefit of the RUCONBAR barriers, however, is that they are environmentally more sustainable that standard concrete barriers. An analysis of their environmental impact found that their lifecycle carbon emissions (including energy used in production) are 31% less than the most commonly used noise barriers in Croatia. They save on raw materials, and prevent the dumping of old vehicle tyres in landfill sites. Per kilometre, the RUCONBAR noise protection barriers use 46.4 tonnes of recycled rubber, obtained by recycling 7,800 waste car tyres. The project notes that this is a potentially significant use of old tyres, because an estimated 30% of waste tyres are disposed of annually in landfills in eastern Europe and the Western Balkans. In western Europe, the proportion is much lower, at about 5%.
The RUCONBAR project started in September 2011, with a total budget of €1.1 million (50% funded by the Eco-innovation initiative). It will conclude in 2014. It will test the sound reduction barriers in real-world conditions by installing them along a busy road carrying car and tram traffic that runs alongside the Zoological Garden of Zagreb.
The objective will then be to develop the sound barriers into an easily transferable and replicable product that can be marketed in Croatia and beyond. RUCONBAR foresees initial marketing of the sound barriers in Bosnia & Herzegovina, Bulgaria, Croatia, Montenegro and Serbia, where the market demand is forecast to amount to more than 745,000 kilometres of sound reduction barriers.