What hardens in asphalt

Saxon construction company wants to conquer the market with chewing gum asphalt

Ebersbacher Baustoffwerke produces a new mixture to plug street holes in a flash

By Nils-Eric Schumann
The managing director of Ebersbacher Baustoffwerke am Wetterberg (Meißen district), Frédéric Robert-Kasper, likes to plug holes. It doesn't matter whether it's big or small, the main thing is that it's a hole in the road. Because since November 2011 the company has been producing special chewing gum asphalt exclusively throughout Germany and hopes to fill a gap in the market with it. Robert-Kasper is happy to demonstrate the new asphalt to interested parties: an employee fills the cold asphalt into a hole in the street on the factory premises in a few simple steps and taps it down with a tamper. Robert-Kasper waves to a truck that drives over the mended hole. The mixture spreads like chewing gum in the former hole and fills even the previously uncleaned edges. The road construction company "strabau Meißen" from Niederau, 15 kilometers away, bought the license for the German market and continental Europe from Macismo from Worcester, UK, explains Robert-Kasper. Because the company does not have its own bitumen plant, it has the asphalt manufactured by its long-term cooperation partner in Ebersbach. In Worcester, the new asphalt has been manufactured under the brand name “Macfix” for seven years. The search for a licensee in Germany turned out to be difficult, however, because the large construction companies showed no interest, says Robert-Kasper. The civil engineer believes that there is a lack of enthusiasm for vision in the industry.

Photo: Jörn Haufe / dapd

The asphalt can also be processed in frosty conditions
The chewing gum asphalt offers many advantages for road construction. The building material can be stored in the open for two years and is easy to process even in frosty conditions. “The potholes only need to be roughly cleaned,” explains the expert. The mixture is then applied in layers. The edges of the holes do not have to be cut out because the asphalt will bond with the old bitumen surface. The roads can be released immediately after the work. The chewing gum asphalt forms a crust on the surface and hardens in a few days. This means that the special asphalt differs fundamentally from conventional cold asphalt. The exact recipe of the chewing gum asphalt remains the secret of the British inventors, emphasizes Robert-Kasper. “I don't know the substance myself.” The viscous mass gets its properties from an additive based on petroleum. This additive ensures that the old asphalt changes at the edges in the pothole and connects with the chewing gum asphalt. The new patch is now also available as “green asphalt” with a vegetable oil-based additive. Strabau and Baustoffwerke are marketing the new product together. Samples were initially distributed in the region, but there are now interested parties from Switzerland and the Netherlands. The product will soon be listed in a hardware store chain. Fraport AG, the operator of the Rhein-Main-Airport in Frankfurt, also wants to test the asphalt for the repair of apron areas. According to the manufacturer, the State Office for Road Construction and Transport in Saxony wants to come next
Winter use chewing gum asphalt for quick repairs on highways.

300 tons of the mixture are to be produced in 2012
This year around 300 tons will initially be produced in Ebersbach, later a quantity of 1,000 tons and more will be possible. In comparison, the same plant mixes an average of 70,000 tons of hot asphalt annually, which the company mainly produces. The building yard of the city of Großenhain, which was one of the first testers in Saxony, is convinced of the chewing gum asphalt. The new cold asphalt is easy to store and easy to process, said a city spokeswoman. The city can imagine using the chewing gum asphalt mainly for urgent repairs and minor damage. "This is exactly what the chewing gum asphalt is intended for," emphasizes Baustoffwerke boss Robert-Kasper. It is an innovative patch for the immediate repair of potholes. But if the road is largely broken, the subsoil and road surface will have to continue to be fundamentally renewed.