Of course, car tires belong to the road. Over the past two decades, they have increasingly found their way into the road. This can be achieved by recycling used tires and VESTENAMER®, a process aid manufactured by Evonik Industries for the rubber and construction sectors.
The European road network is now nearly 75,000 kilometers in length and is expanding steadily. As with new construction, roads and bridges must be maintained to maintain continental European traffic, as well as related economic growth and mobility.
As additional complexity, the number of vehicles owned per 1,000 inhabitants in the European Union has more than doubled since 1975, and long-distance freight trucks have also increased significantly. According to statistics from the European Commission, truck shipments in 1990 amounted to approximately 1,000 billion ton-kilometres, but by 2015 they had increased to 1.75 billion ton-kilometres. These developments pose major challenges to European infrastructure.
Road Construction Innovation
Road quality and durability are major concerns of the public sector. To avoid ruts and cracks, and to save maintenance costs, the demand for high-performance road building materials is clearly attracting public attention. At the same time, the cost of raw materials for bitumen, especially bitumen-modified compounds, has increased significantly, which has created another obstacle to cost-effective road construction. Obviously, alternative concepts need to be chosen.
Evonik is seeking a sustainable, cost-effective way to build roads. VESTENAMER® is a process additive used by the rubber industry made by specialized chemical companies, making it possible to produce rubber-containing asphalt from rubber powder processed from waste tires. Recycled materials are incorporated into road construction asphalt or asphalt to improve the quality of the mix and extend the service life of the pavement.
Extends service life and reduces noise
In the United States, rubber-containing asphalt mixtures have been used for decades. Long-term studies have shown significant improvements in road durability. Frank Lindner, senior business manager for VESTENAMER® products, said: "In the past few years, the market for elastomer-modified, rubber-containing roads in Europe has also grown. Because the material has significantly reduced cracks, ruts and Potholes extend the life of the road, so its superior performance is obvious. "
Another sensory experience also supports the use of rubber-modified asphalt: rubber powder is often used in porous asphalt, also known as low-noise asphalt, which reduces traffic noise. Scientific research proves that using a larger proportion of rubber powder on the road can reduce the noise of 1-2 decibels. This is very important, because in human perception, reducing 3dB of noise is equivalent to reducing noise by half.
Reasonable and efficient use of used tires
Each year, approximately 19.3 million metric tons of used tires are produced worldwide, of which more than 3.6 million metric tons are in Europe alone. Twenty years ago, more than half of used tires in Germany were burned to generate electricity, and only one out of every ten used tires was processed into pellets. So far, the latter's mass has caught up with energy-related processing.
Recycling used tires is definitely environmentally significant. Thomas Engenhorst, Sustainable Strategy Manager at Evonik's Resource Efficiency Division, said: "Recycling recycled tires ensures a valuable resource-tires are not classified as waste, but are considered a valuable material, for example, not in waste Landfill disposal. This use eliminates disposal issues: tires are not incinerated but are at another stage of life in road traffic-not as part of an engine-powered vehicle, but in the form of elastomers or rubber powder On the road. "
As part of the test track in the town of Paderborn, Germany, the local road Detm.Strasse was repaved in 2012 in accordance with the objectives of the EU waste directive. 50% of the new asphalt mixture is made from ground material-asphalt particles-from the old road. The new blend formulation also includes rubber powder and VESTENAMER®. For every 100 meters of track, about 80 waste tires turn into an elastomer-modified pavement, along with recycled old asphalt.
Reduce carbon dioxide emissions
A study by the renowned Heidelberg Institute of Energy and Environment (ifeu) provided further information on the ecological balance: Each metric ton of recycled rubber powder can save about 2.7 metric tons of carbon dioxide that would be generated during incineration. Therefore, the use of this material significantly optimizes the carbon footprint.
The application of VESTENAMER® is clean in many ways: volatile and semi-volatile compounds, including hydrocarbons and sulfur compounds, emit significantly less on rubber-containing roads than traditional polymer-modified asphalt types.
In addition, Evonik's process additives reduce organic compounds washed away by rainwater and reaching the groundwater. As documented by the research conducted by FABES Forschungs-GmbH on behalf of Evonik, the use of VESTENAMER® reduces the overall groundwater burden.
In the spring of 2013, the Road and Transport Research Association added rubber-modified asphalt and asphalt types to German road construction regulations.
VESTENAMER® was developed in the late 1970s as a processing aid for the rubber industry. Polyoctene rubber produced by Marl Chemical Park addresses many of the challenges associated with rubber compounding and processing. Because it has positive properties in its interaction with other rubbers, it has been used to this day. In addition to the tire market, this product plays a role in the manufacture of rubber products such as hoses, clutch linings, roller coatings or molded parts. As road transport authorities have long been looking for an improved and more durable material, Evonik's high-performance polymer business line began extensive research in this area 10 years ago. Since then, VESTENAMER® has gradually become the unified choice for rubber-modified asphalt.