Asphalt vs Concrete: Ecological Battle of Road Surfaces

Every year, Russian cities and villages are “overgrown” with hundreds of kilometers of new road infrastructure, making the life of residents more convenient. Of course, the construction of roads in itself is a necessity, but the usual materials for new streets, highways and overpasses cause great concerns among environmentalists from the side of safety.

Rarely where among the many cities of Russia you can find any other roads than asphalted ones. Asphalt concrete pavements are laid both in small adjacent areas and on wide highways. In summer, the heat from the asphalt turns the already stuffy stone jungle into a real red-hot oven. At the same time, anyone can notice that on hot days over new asphalt, which, by the way, is laid most often in the warm season, even the air seems to “tremble”. And this “trembling” does not bode well for our organisms.

Back in 2004, the State Sanitary and Epidemiological Supervision published a study in which he found out that asphalt pavement in urban areas is a source of harmful substances. It is logical that in this situation, the living of people in cities with a large number of roads has a bad effect on their well-being. Moreover, both fresh coatings and long-standing roads are dangerous. Comparative chemical analysis showed that the content of heavy metals, in particular lead, reaches a maximum in coatings laid 2-5 years ago. The fact is that many harmful substances and heavy metals accumulate in the upper layer of the asphalt pavement, which gradually enter the environment. But the most interesting thing is that it turned out that the concentration of heavy metals in asphalt laid in pedestrian zones and yards is significantly (sometimes several times) higher, since they are usually made of a more porous and cheaper material that literally absorbs dirt like a sponge.

As for the “harmfulness” of new roads, Yale University researchers claimthat fresh asphalt is produced from crude oil or similar substances. It consists of organic compounds – some of them enter the air in significant quantities. And the fresher the asphalt, the less fresh the air around it. The greatest amount of compounds is released into the air when the asphalt has a temperature of 140 degrees. And it is at this temperature that it is laid. Until it cools down, all harmful substances evaporate and soar in the air.

Another interesting fact is that it additionally affects emissions and sunlight: its effect on asphalt increases them by 300%. The conclusion of the Yale researchers is disappointing: asphalt spoils the air no less than the cars that drive on it. By allegations officials, asphalt pavement has emissions of harmful substances. As the temperature rises above 25 degrees, these emissions increase and become already significant in terms of human impact.

“Asphalt concrete pavements contribute to an increase in vehicle emissions. When driving on such roads, especially if they are of inadequate quality (repair of asphalt concrete pavements in Russia is carried out every 3 years), fuel consumption increases by 5-7%, and, consequently, exhaust gases. This is due to the formation of the so-called “bowl of deflection” and the coefficient of rolling resistance of the car increases, “- comments the President of the Association of Concrete Roads, Head of the Department of Construction and Maintenance of Roads” MADI Viktor Ushakov.

He added that in addition to the obvious non-environmental, asphalt pavement in cities has other disadvantages associated with mechanical properties. For example, as the temperature rises, the pavement becomes more pliable and ruts form, which affects road safety. By the way, by data Ministry of Internal Affairs, almost a third of accidents in the country occur due to shortcomings in the transport and operational condition of roads.

Against the background of these data, it is somehow even inconvenient to talk about the obvious harm from asphalt production in the city. They accompanied harmful emissions into the atmosphere, including dust containing free silicon dioxide (silica), soot, sulfur dioxide (SO2), nitrogen oxides (NO, NO2), carbon monoxide (CO) and polyaromatic hydrocarbons (PAH).

Even if there is no asphalt plant in your city, there are certainly roads. And now what? Take a one-way ticket to a remote village? Of course not. An alternative to asphalt concrete pavement has been known for a long time. In the USSR, during the concrete-industrial boom, concrete roads began to be built. In total, they laid about 10 thousand km. However, in the 1980s, this solution was completely abandoned. A significant disadvantage in their construction is that you need to wait at least a month, and only after that start moving. But that was more than four decades ago, today the technology has moved far ahead.

“An alternative to asphalt is the construction of roads with cement concrete pavement, which have a large list of advantages. Not only are they more durable, they also require fewer repairs. The fact is that in a warm climate, cement concrete roads do not melt and do not deform, but in the cold they do not become brittle and do not crack, ”says Ushakov.

According to the speaker, concrete roads can withstand increased loads, so heavy vehicles can drive through them all year round, without restrictions. Such roads are more environmentally friendly: cement does not emit toxic gases when heated and is 100% recyclable. Due to the hard surface, fuel consumption when driving on concrete roads is reduced by 3-6%. And the lower the fuel consumption, the less carbon dioxide emissions into the atmosphere.

“According to statistics, in Russia, asphalt pavement on major highways and in cities is repaired every three years. For repair work, it is necessary to block entire sections of roads, which naturally leads to traffic jams and congestion of cars, especially in large cities. In addition, during the repair there is a large waste of energy, fuel and other materials,” Ushakov added.

It turns out there is an alternative. Why are road services so reluctant to use it today?