Due to the fact that car tyres are exposed to the same weather conditions as road surfaces, their composition and properties make rubber an almost ideal asphalt modifier. It is a very technologically advanced material.
Roads in the rubber asphalt technology have much better parameters than other existing technologies, e.g. in terms of:
– Technologies of rubber asphalt from used tyres during the entire period of road maintenance will provide the investor with financial benefits, greater safety for drivers, and greater comfort of life for local residents. The rubber raw material from used waste tyres has a very positive effect on almost all properties of mineral-rubber-asphalt mixtures (AMG). In addition to improving safety, a particularly important advantage of this technology is the significant reduction in noise from roads, which has recently become a nuisance for residents as more concrete roads are opened – points General Director of the Polish Tyre Industry Association (PTIA).
It is therefore a technology that is both effective, easily accessible and ecological – approximately 3,400 tyres are used to make a kilometre of AMG wearing course on the expressway. In addition, the economic aspect, i.e. reducing the cost of maintaining the pavement due to its increased durability, makes rubber asphalt an optimal and future-proof solution.
– Polish recycling companies are ready to supply high-quality rubber raw material from used tyres on a scale sufficient to start the national road construction program of rubber-modified asphalt. We can base on the federal road construction program with the addition of rubber from used tyres, introduced in the US in the early 1990s by President George Bush as an example – ads Maciej Jasiewicz, president of Recykl S.A. Organizacja Odzysku.
The method of modifying asphalt parameters using rubber from used tyres has been studied, developed and successfully used in Poland for over a dozen years. Meanwhile, it is still not as widely used by investors and road managers as possible.
The asphalt-rubber mixture (AMG) is more resistant to thermal cracking, and also has a lower stiffness modulus and a greater stress relaxation capacity. In practice, this means that the mineral-rubber-asphalt mixes for the wearing course under low temperature conditions will not crack at all, or the crack will develop much more slowly and the layer will maintain its structural integrity almost to the very end. The above properties are also associated with greater resistance to fatigue and reflection cracks. In the United States, the analysis of pavement condition data collected over 20 years from more than 500 road sections showed that pavements with AMG have a crack index three times lower compared to roads with other types of asphalt[6].
Another positive aspect of the use of AMG mixtures in the road surface is the increased resistance to permanent deformation caused by high temperature. In addition, AMG wear layers have better anti-skid properties (rubber particles on the surface of the aggregate grains increase friction when the tire contacts the road) and reduce noise.
[1] Federal Road Construction Program with Waste Tire Rubber - G. H. W. Bush 88-92, 24.2% of all used tires in the USA in 2017 were converted into 1 million tons of rubber dust
[2] Government program in Spain since 2002, +1 600 km of rubber roads, 1 million tonnes of asphalt-rubber mixtures
[3] M1 k. Leicester Highway
[4] DK 20 near Kościerzyna, DK 7 near Czosnów, S7 near Kraków
[5] American Concrete Pavement Association Mid-year report 2005
[6] G.B.Way, K.E.Kaloush, K.P.Biligiri, „Asphalt-Rubber Standard Practice Guide, Second Edition”, Rubber Pavements Association, Phoenix 2012.
Source: Polish Tyre Industry Association