Why are the roads so bad in Russia? Are overloaded trucks, studded tires and high speeds always to blame? Partly yes, but the main reason lies elsewhere.
Probably, many have seen live and on various videos on the Internet how road workers laid asphalt directly into a puddle or even into a snowy mess sprinkled with mud and reagents. After this “technology” the coating, at best, lasts for several months, after which it goes in waves. And clearly the climate is not to blame.
Indeed, quite often, especially in the southern regions, you can find roads with a pronounced rut. In the right lane, where heavy trucks usually travel, there are two pronounced crushed ditches and asphalt bulging in the middle and on the sides.
It is heavy trucks that push these ditches. Such rutting is called plastic, since the reason for its appearance is the irreversible (plastic) deformation of the coating.
Heavy trucks are only a catalyst for the appearance of plastic track, but not its cause. And the reason lies in the poorly prepared base before laying the asphalt. For example, they used cheaper crushed stone of an unsuitable size, it was not compacted enough. Sometimes deformation of the upper layers occurs due to poor bitumen.
All these violations of technology lead to the fact that under the influence of high temperatures in the summer, the asphalt softens and deforms. This happens especially quickly under the influence of a large flow of heavy vehicles.
Still, there are roads in our country, the foundation of which is made of a fairly high quality, but there the track appears for other reasons. One of them is studded wheels.
Pavement damage caused by spikes can be found where cars can start slipping, such as in front of intersections at traffic lights. Wheel spikes are capable of scratching a groove in the asphalt up to half a millimeter deep.
A similar effect is observed when the front wheels are turned in place. And this is in frosty weather, when the asphalt is harder due to low temperatures. During the thaw, the effect is even stronger.
A good example is the Moscow Ring Road. Long-term observations show that rutting there most often manifests itself in the left lane. The reason is that mostly good and expensive cars with high-quality new studded tires, in which all the studs are in place, move along it. And they move quickly. And this leads to another reason.
As with heavy trucks, high speed is only a catalyst, not the root cause of asphalt deterioration. The thing is that the coating deteriorates only in those areas that were not originally designed for such a speed of passage. In Europe, for example, on high-speed sections, a mixture of asphalt and crushed stone is used, where the share of the latter is at least 70-80 percent. In our country, this ratio is at best 50 percent – it is cheaper and easier to install this way.
Abroad, special gravel-mastic asphalt concrete (SHMA) is also massively used for high-load highways. This mixture, containing tough crushed stone from dense rocks, creates a tough carcass, which is reinforced with special cellulose fibers.
In general, rutting problems are not rooted in cars or the climate, but in violations of technology. For example, two-layer styling prescribed in the technology is not used. In addition, at least two days must pass between works. We still use patching and surface repairs, removing the top layer of asphalt and replacing it with a new one. In this case, damage to the base is not taken into account. In Europe, such “patches” have not been practiced for a long time.
When it comes to laying asphalt in rain and snow, this technology does exist. For this, however, you need a special mixture of crushed stone, sand and bitumen with special additives, moreover, preheated to 200 degrees. It is poured and not compacted with a roller. The technology is quite expensive and rarely used. And if you watch how the asphalt is put into a puddle, there is no special thermos tank nearby, but only road workers with shovels, then this road will not last long.