Road construction is required. Do-it-yourself roads: from need to self-interest

Construction work is carried out almost continuously day and night. Everyone has probably seen more than once how builders put asphalt on roads, but they hardly thought about what the whole process of building a road is like.

The first stage of any construction (or reconstruction) is design. Then held geological surveys, which determine the relief of the territory, the composition and properties of the soil, the state of soils, atmospheric air, surface waters, etc. Based on these data, a road construction plan is being developed.

Further construction work can be conditionally divided into the following stages:

• preparatory work (cutting down trees, dismantling fences, etc.)
• excavation(removal or importation of soil, strengthening of subgrade, construction of earth embankments, etc.)
• laying new or re-laying existing engineering communications falling within the construction zone
• arrangement of the bases of the "road pie" (device of the underlying layer of sand, "filling" the base of crushed stone or concrete)
• asphalt paving
• landscaping of areas adjacent to roads (marking, installation of fences, road signs, curbs, storm sewers, road lighting, etc.)
• environmental protection measures (replacement of windows in those located near the road residential buildings, installation of noise barriers along the road)

One of the most important elements of road construction is asphalting, when the prepared subgrade base (stone or reinforced concrete "skeleton") is distributed asphalt mix, then she "tramples down" - and the road is ready. The service life of the road largely depends on how high-quality this mixture will be and how professionally the work will be carried out. After all, it is not by chance that the top layer of the road surface is called the “wear layer” - every day a huge mass of passing cars presses on it.

Asphalt laying can be made from various materials: asphalt concrete, poured asphalt, crushed stone, crushed stone impregnated with bitumen, gravel or impregnated soil, etc. Often, bitumen or so-called secondary building materials are used in the construction of roads: asphalt chips, broken bricks and asphalt chips.

The most common building material is asphalt concrete. Asphalt concrete is crushed stone, sand, stone flour and actual molten asphalt mixed together. This "stuffing" is laid out on an earthen base in several layers. By the way, it is because of the multi-layered nature of the roadway that it is often called the “road pie”. The number of layers depends on various factors, but above all on the expected traffic load.

Larger gravel is placed in the lower layers of the "pie" so that the road is strong, stable, and durable. And smaller crushed stone is poured into the upper layers - this gives the road surface such qualities as high wear resistance and water resistance. In addition, due to the presence of small gravel, the road surface is somewhat rough, and this is necessary so that the tires of the cars do not slip.

Another type of asphalt is the so-called cast asphalt. It is a mixture cooked at very high temperatures. The viscous-fluid mixture is brought to the construction site in special containers that keep the temperature, and the hot mixture is poured into the place of the future road. A road made from such asphalt can withstand heavy traffic loads, resists wear and tear and the effects of studded tires and anti-icing agents. In addition, poured asphalt absorbs noise well.

Asphalt is laid with the help of special equipment - asphalt pavers. The roller compacting the asphalt makes the road surface even and strong. By the way, there is such a kind of skating rink as a vibratory skating rink. Its constant vibration gives additional "tamping", and the asphalt becomes even more dense and durable.

Road construction is constantly being improved. New technologies are improving the composition of the asphalt pavement, making roads even safer and more durable. To be included in the composition of asphalt, special components are being developed that improve the grip properties with car wheels - on such roads, drivers are not afraid of rain or light icing. New modifiers for bitumen allow asphalt concrete not to crack at sharp temperature fluctuations. Such a modified bitumen, combined with granite fillers and special additives, will protect the coating from the "whims of nature" when the roads either freeze or thaw, from which their quality deteriorates.

According to the standards, pavement should serve without repair from ten to eighteen years. Surprised? According to the head of Rosavtodor Roman Starovoit, Russian road builders give a guarantee for coverage from four to eight years, but within twelve years they are obliged to eliminate emerging defects at their own expense.

They can significantly increase the service life of roads - but are they applicable here?

Tire by tire

The most interesting and useful -. For example, the composition of the so-called rubber asphalt includes crumb rubber obtained from old tires. Such asphalt is suitable for any climate, provides excellent grip, reduces braking distances by 15%, reduces noise, withstands heavy loads and is not prone to rutting. It is also extremely important that it allows you to solve one of the environmental issues by recycling old tires, of which about 300 million are accumulated annually in the USA alone!

However, Unirem, a modifier of asphalt concrete mixtures, obtained from old tires, is already widely used. According to the developers, active (with additives) rubber powder increases the durability of the road surface by 25%, reduces rutting by half and does not require changes in the asphalt concrete production technology. However, asphalt with a modifier, which the wits have already called "nano-asphalt", requires impeccable adherence to the laying technology. Otherwise, the road becomes covered with blisters and it becomes impossible to drive along it, as happened in Ufa and Irkutsk. A reverse example is the M10 Rossiya highway (386–388 km, near the roadside complex Polputi), where the nanoasphalt has been lying since 2005, not requiring replacement. But every day thousands of cars and heavy trucks pass through this area.

But since 2014, Russian road builders have been using the American word superpave (in translation - super coating) - this is the name of the method of volumetric design of asphalt concrete, which allows to improve its quality, use local materials without reducing the wear resistance of the coating (for example, a stone going into asphalt concrete may be inferior in density to stone from another area). Superpave makes it possible to design the composition in such a way that the strength characteristics of the road surface will correspond to the specified ones - and complex logistics and additional costs will not be required.

If only you knew from what rubbish ...

Two years ago, a 122-kilometer expressway was built in the Chinese province of Shanxi, using 6 million tons of construction waste to build it. Thanks to this, the Chinese saved about $47 million, 3.4 million cubic meters of sand, 32 tons of coal and, very importantly, 200 hectares of land that would be required for waste disposal. We also use construction waste - a kind of "barbecue" from pieces of concrete strung on reinforcement, but such "roads" are unsuitable for passenger cars. They are constructed as temporary during construction. And if they were filled with asphalt concrete, which can also be made from recycled materials, the road would be quite suitable for mass exploitation. After all, there are road surface regeneration technologies that allow using a significant part of the old asphalt mix for the production of a new one (primarily in the factory, after remelting).

Cold recycling technology is even more interesting and environmentally friendly. Old asphalt is cut off, crushed into crumbs and, mixed with a new binder, a new coating is made right on the road. In 2014, this technology was demonstrated to the head of Rosavtodor in Khabarovsk, and now Russian road builders are ordered to use old asphalt as much as possible - this way they can save up to 40% on materials. Today in Russia, some companies are repairing roads using cold recycling technology, but so far this is the exception, not the rule.

Dutch company Royal VolkerWessels

StevinN. V. A couple of years ago, she unveiled the Plastic Road () project - she proposed to make a roadbed from cast plates, connecting them end-to-end, like parts of a children's designer. The principle is not new; the so-called concrete blocks are built in the same way. Only the Dutch offer to cast slabs not from concrete, but from plastic obtained from the processing of waste caught in the oceans - bottles, bags and other rubbish.

Plastic roads can also replace ordinary asphalt roads by removing all the upper layers and leveling the base. At correct installation it turns out an almost perfect surface with subtle joints. Damaged segments are easy to replace, and since the slabs are hollow, electrical cables and communication lines, sewerage and gas mains will be placed inside. If necessary, you can even make heating.

But in Russia, according to experts, this technology is unlikely to take root. If only because they are prohibited in the Netherlands, and in our country they are widely used. In addition, according to the head of the metropolitan testing laboratory building materials Rauf Yusifov, a plastic coating, even in summer, is not able to provide a coefficient of adhesion sufficient for safe movement, not to mention winter: “Macroroughness can be created by forming longitudinal and transverse grooves that will be under the wheels, but the microroughness necessary to remove film water is artificial not create." Yury Vasiliev, professor of the Department of Road Construction Materials at MADI, speaks in the same vein. He also recalls that household waste is still not sorted and it is difficult to separate plastic waste from other waste. And to use new plastic for the production of road slabs is too expensive.

Plastic coating can only be used on sidewalks, footpaths, alleys, on the roadway with a longitudinal slope of not more than 20% and low speed (up to 40 km / h). That is, in parks, not on highways.

However, we already use plastics in road construction, and in such a volume that other foreign road builders will envy. For example, for the construction of electric lighting masts and their supports, noise barriers, bridge crossings. Composite materials are used for formwork, prestressed reinforcement, railings, shields, luminous paints based on phosphors.

Dreams Dreams

In the Netherlands, road builders dream that it reacts to temperature changes - this is already being tested on one of the routes in the south of the country. The British dream of a marking that accumulates energy during the day, and at night it glows the more, the darker the night. There is the idea of ​​smart roads that warn drivers to slow down by lighting signs on the pavement when a pedestrian or animal steps on it. Many people dream of roads with built-in solar panels: the energy accumulated by them should be enough to light the road, and even for contactless recharging of passing electric vehicles. For example, in the state of Idaho (USA), a road surface was created from solar panels that can withstand trucks weighing up to 115 tons.

And the book, published in 1816, said that the foundation of the road should be laid out from large stones, and several layers of gravel crumbs, filled with tar, were applied on top of them. For adhesion of the layers to each other, they should be compacted with a roller, and the size of the gravel crumb should decrease from the lower layer to the upper one. The roadbed must be raised above ground level, and the profile of the roadbed must be made convex - in order to rainwater ran down the curb.

In fact, they tried to develop and apply such methods even before McAdam, but he was the first who brought the entire body of knowledge to a coherent theory and gave it a powerful practical impetus. In 1828, crushed stone rollers were introduced in Great Britain (steam rollers would appear much later, in 1859) - the year before, McAdam had been appointed chief inspector of roads in Great Britain. Subsequently, he also became the chief engineer of Great Britain, his theory quickly became universally recognized in all developed countries ah, and then the start of the automobile era arrived in time. In honor of the anniversary of the publication of a book so significant for modern motorists, we decided to collect in one material Interesting Facts about how the roads are now being built in different countries peace. So what do we see 200 years later?

USA

In North America, all roads are divided into groups according to their importance, and we are especially interested in the two highest ones - Interstate Highways (indicated by the index I) and US Highways (US), the so-called highways (the fastest of them are also called freeways), in our way highways. All highways in the United States are made of concrete, and even if an asphalt surface is found, it is temporary - in the States, “concrete” is covered with asphalt in order to delay the overhaul.

Such a trick is used for a reason - the overhaul of a concrete highway is identical to the construction of a new one, but with the addition of work to dismantle the old highway. Concrete is difficult to repair and difficult to lay – if an asphalt pavement is ready for use after 8 hours, then concrete only takes 28 days to reach its final strength, and it takes several months of continuous work to open a concrete road. Why such difficulties?

Highways carry the maximum flow of cars and cargo, and concrete is strong, durable and resistant to high loads arising from the overweight of trucks. Guarantee period operation of a concrete highway is 25 years, but in practice they serve for 30-40 years, and the cost of maintaining the route is minimized. Until now, there are sites put into operation in the 1960s and are in excellent condition.

During the construction process, a meter of soil is selected under the future route, a pillow of gravel, sand and clay is laid in layers and rammed into the resulting trench, then it is poured with lime mortar or calcium chloride solution, loosened and rammed again. As a result, the pillow is able to retain a constant percentage of moisture almost forever, which means it does not sag or swell. Further, two layers of asphalt with a total thickness of 5-7 cm are laid on the pillow, but the asphalt in this case is only a flat platform for a layer of concrete, as well as waterproofing, which does not allow water to flow under the concrete sheet through thermal seams that connect the fragments of the sheet to each other. A reinforcing mesh is laid on the asphalt, which the concrete paver pours with a layer of concrete 30 cm from one thermal seam to the other to obtain a monolithic canvas. And then follows almost a month of waiting until the concrete "gets up".

At overhaul the track is not blocked, but temporary understudies are made of asphalt on the sides of the road, or first one side of the track is repaired, and then the second, but strictly observing the rule - the throughput should not decrease by more than 30%. Repair areas are fenced off with curbs, marked with signs, cones and constantly updated information boards, and temporary understudies are provided with markings from convex glow-in-the-dark chips. Penalties for non-compliance with traffic rules in repair zones have been doubled, violation of the speed limit is especially severely punished.

The finished highway includes at least two lanes in each direction, oncoming lanes have a constructive separator and do not fit closer than 10 meters to each other. The right side of the road has a width of at least 6 meters, the left (yes, there is one, but it is forbidden to move onto it) - at least 3 meters. According to safety requirements, the maximum angle of ascents and descents on the highway is 6%, the maximum load is 36 tons. There are no roundabouts or loopholes familiar to us, there are understudies for exits to minor roads. Speed ​​limit on highways: minimum 30-40 mph (60-80 km/h), maximum 60-80 mph (100-130 km/h).

Road construction in the USA is profitable state business. The federal highway fund fills up with auto taxes, tolls, private investment, stock sales, and also through the sale of fuel - 2.5 cents goes into the fund for every gallon (4 liters) of gasoline poured into a car tank. This last article alone brings in tens of billions of dollars annually for the foundation.

Roads transport $6 billion more cargo a year than railroads – it’s more profitable that way. The entire transportation infrastructure is valued at over $2 trillion—more than 15% of the value of all US manufacturing assets. Today, more than 300,000 people are employed in the US transportation infrastructure, and every billion dollars invested in it creates 35,000 more jobs, and also avoids more than 1,500 deaths and 50,000 injuries in road accidents. Over the past 40 years, every dollar invested in road construction has saved two in health care, insurance, unemployment supplies, and increased productivity.

Great Britain

Gradually, the American experience in the construction of "concrete" migrates to Australia, Asia and Europe. At the beginning of 2016 in Scotland, in the homeland of John McAdam, two mobile concrete plants were put into operation, with a capacity of 90 and 140 cubic meters of concrete per hour, respectively. These factories have beautiful names, Mobile Master-100 Lion and Mobile Master-150 Elephant, and a wheeled chassis that allows them to move from one site to another, constantly supplying the construction site with concrete. This is especially important as Lev and Slon are building a transport route in the Aberdeen Western Peripheral Route project, which includes 58 kilometers of new highway, 40 kilometers of detours, 30 kilometers of ramps, two bridges across the Dee and Don rivers, and about 100 more structures. and objects.

There are about 344,000 kilometers of paved roads in the UK, and at the moment most of them are asphalt. As a more traditional and familiar variant of road construction, let us consider the arrangement of streets in the cities of England. Let it be London, although travelers say that the quality of roads in England is more or less the same everywhere. The pavement of the streets is asphalt, and it undergoes trivial patching and cosmetic repairs, but not at the moment when the road becomes unusable, but at certain intervals - that is, simply according to plan.

England is one of the rainiest places on Earth, but, oddly enough, it is impossible to even imagine that the asphalt of the city streets here collapsed after the rain. English asphalt is very durable, although in most cases, due to the mildness of the climate, it is not subject to severe frosts. If a hole appears, employees circle it with red chalk and immediately after that they roll new asphalt into it. There can be many patches in a limited area, but all of them are perfectly (and for a long time) “fitted” into the roadbed.

Another feature of English roads is the transverse slope. It is always there, because it is an easy way to ensure the flow of water. Draining from the canvas, the water reaches the curb, and from there it enters the storm outlet. Leaves and other debris remain at the curb, from where they are raked by a harvester.

The infrastructure of the streets also deserves attention. As they say, it is unbelievable, but true - bus stops are installed with glass to the roadway so that passengers are protected from dust and splashes. On wide streets, safety islands for pedestrians, enclosed by a fence, are obligatory. At pedestrian crossings, in the exit area to the roadway, special tiles with anti-slip coating have been laid. And the pedestrian crossings for motorists themselves are indicated by two orange lights on striped poles - they are clearly visible both day and night.

Germany

Fast forward to Germany, famous for its autobahns. The surface of the autobahn can be either asphalt or concrete. But under this top layer there is a multi-layered pressed “cushion”, similar in structure to the American one and having a depth of up to two meters.

During the construction of a concrete autobahn, the road is covered with a special film that protects the drying concrete from the sun and precipitation. In the event of rain, when creating an asphalt road, builders simply stop work until the site is completely dry.

All roads have a warranty period of operation, and during this period, road companies eliminate all deviations from the norms at their own expense. Pothole repairs are not in use here - a large section of the road is measured at once, because any inaccuracies, errors and further destruction of the canvas are fraught with huge lawsuits.

A significant part of modern roads in Germany was built back in the days of the Third Reich and is designed for the movement of columns of heavy military equipment, so these roads still successfully cope with the huge traffic of trucks. And the first German autobahn, still in operation, is over 80 years old.

Finland

Finland, along with the UAE, France, mentioned by Germany and more European countries, regularly ranks among the top ten countries with the best roads, despite the harsh climate. Here, too, much attention is paid to the multi-layer rammed cushion, which serves as the basis for the future road.

The Finns have learned how to build roads even on unstable soils - special stabilizing additives are introduced into the substrate of peat or clay. In this Scandinavian country, even dirt roads are maintained in a stable condition.

Helsinki was one of the first places in the world to have heated pavements that keep them dry during the winter, a first in the Finnish capital in 1998. Over the years, the road construction experience of developed countries has come to the conclusion that it is often much more profitable to heat the canvas than to sprinkle with reagents, and to date, heated sidewalks, bus stops, railway platforms and roads, in addition to Finland and other Scandinavian countries, are in the USA , Canada, even in Russia (however, an experimental site with a heated sidewalk near the Moscow City Hall, launched in 2003, can hardly be considered a serious achievement) and, of course, in Japan.

Japan

In Japan, sidewalks and roads are heated in absolutely all cities where snow falls in winter. By the way, the climate of some regions of Japan is also not very mild - for example, in Hokkaido the average annual temperature is only +8 °C. There is also heating on the tracks, so even in heavy snowfalls, there are usually no snowflakes on these roads.

Concrete also serves as the main material for pavement of roads here - due to reasons already known to us: durability, strength, resistance to high loads. The construction technology repeats the American one, but in Japan another plus of concrete is also actively used - it allows you to translate the most complex multi-level interchanges into reality.

Specialists of various profiles work on the construction site, and each bears full responsibility for his site. A lot of time is occupied by the preparatory stage, because the plan of the future road is worked out to the smallest detail. In addition, if the road must pass through private territory, lawyers and the government need to successfully negotiate the purchase of a piece of property.

China

The Chinese, in their eternal desire to overtake their neighbors, have reached unprecedented rates of road construction. Chinese companies are able to provide a speed of construction of 750 meters of road per hour, and with a quality that is not inferior to best performance Europe.

Following the American model of road construction, over the past decade and a half, the Chinese have built over 70,000 kilometers of highways, and present moment rates approached the mark of 30,000 kilometers of motorways per year. The warranty for roads in China is 20-25 years.

Georgia

In the second part of the story, we turn to some countries former USSR. Their culture of road construction after the collapse of the Union was formed in different ways. In Georgia, for example, the roads have always been relatively good - partly due to the stable rocky ground.

V last years a widespread restoration of old roads and the construction of new ones are being carried out: secondary rural roads are covered with asphalt, and intercity highways are made according to the American scheme - from concrete. Although they call it in the German manner - autobahns. Speed ​​limit repeats Russian rules: on highways (autobahns) 110 km / h, on other country roads - 90 km / h.

Since 2012, the Batumi-Tbilisi highway has been under construction in Georgia, and part of this expressway with lighting, cameras, light panels and recreation areas has already been put into operation. Ultimately, the path between the capital and Batumi (about 380 km) should be reduced to three hours. And not so long ago, another autobahn, 17.4 km long, built by the Chinese company Sinohydro Corporation Ltd, was put into operation on the Rustavi-Tbilisi section.

Latvia

Latvia found itself in a completely different situation. This country has always been a little more "Soviet" than neighboring Lithuania and Estonia, and in many ways - in particular, in terms of road construction - this did not serve well.

Until 2003, there was a special road fund in the country, which was supposed to accumulate funds for road construction, but neither its liquidation due to "non-transparency" nor its restoration in a new format, which is currently being discussed, give a clear answer to the question: why are the funds collected by the state taxes do not properly fall into the scope of road construction? What a familiar situation!

Since 2004, Latvia has been a member of the European Union, which allocates money to improve the quality of roads, but by 2018 most of these funds will be spent, and there has been no real progress. The worst situation is with local roads, for which funds European funds use is prohibited. Another painful (and also very familiar) issue is the quality of road repairs. It is natural that the cost of maintaining roads in Latvia is higher than that of its neighbors.

By 2015, out of more than 20,000 km state roads in Latvia, only 9,000 km were paved, of which over 4,000 km were in poor or very poor condition, according to Neatkariga. In 2013, the World Economic Forum conducted a study of the quality of roads in the world, and among 144 participating countries, Latvia was in 99th place, next to Zambia and Zimbabwe. Estonia ranked 61st, Lithuania - 32nd.

Russia

In the 2013 ranking, the countries with the best roads were recognized (places from one to ten): France, UAE, Singapore, Portugal, Oman, Switzerland, Austria, Hong Kong, Finland and Germany. If we continue talking about the former Soviet republics, then Belarus, with its good quality of asphalt and the system of paying for traffic on suburban roads adopted from the UAE using devices installed on cars and reading "frames" on the tracks, was not included in the rating. But Russia got into the rating and ended up in ... 136th place, next to Ukraine and Central African Gabon. Only East Timor, Guinea, Mongolia, Romania, Haiti and Moldova could “boast” with roads worse than in Russia.

In 2015, the alignment of the leaders changed slightly: the UAE came out on top, followed by Portugal, Austria, France and the Netherlands. Closed the list of 141 countries this time Guinea. The United States, from which we began the story, was only in 16th place, and as for Russia, it slightly improved its position, taking 124th place in the list of 141 countries. But, as we understand, such progress does not in any way attract a cause for national pride.

The United States has almost 6.5 million kilometers of roads, including highways, paved and unpaved roads. In Russia - six times less, about 1,400,000 km, and this despite the fact that the territory of Russia is almost twice the size of the United States. Moreover, Japan has almost the same number, 1,200,000 km, and the country's area is 45 times smaller than Russia's!

The length of North American highways (highways and freeways) is over 77,000 km, and in Russia there are barely a thousand kilometers of such. The highways of Finland have approximately the same mileage, which has almost ten times fewer roads than in Russia, not to mention the country's area.

And here is another “territorial” example: what if we compare, say, the roads of Russia and Great Britain and take into account only paved roads? There are 984,000 kilometers of such cars in Russia, according to Rosavtodor. And in the UK - about 344,000 kilometers, that is, about three times less. But this is at total area country is 70 times smaller than the area of ​​Russia! And with a completely different quality of this very hard coating.

We can also recall the 70,000 kilometers of highways built in China over the past 15 years, and the fact that in Russia all federal highways are not highways, but simply "federal roads", where there are places that locals lovingly call "graviyechka" - only about 51,000 km.

The main binding material in the asphalt mix is ​​bitumen, which is produced in oil refineries. According to some reports, the demand for high-quality bitumen in Russia is falling, and its production is declining catastrophically. The road business in the Russian Federation is arranged in such a way that it is unprofitable for a road construction company to buy high-quality bitumen - this negatively affects the volume of orders in the future.

It is better to buy a material similar to normal bitumen, which is essentially oil refining waste with an added binder and costs several times cheaper. This circumstance serves as an additional trump card when participating in a tender for road works, because the contractor who offers the most low price. Asphalt obtained using this "bypass" technology has a shelf life of up to 1 year, after which it is destroyed, and the company has the opportunity to receive a new work order.

In 2011, the website of the RosYama project was launched in Russia, which allows users to file a complaint with the traffic police about a road defect that does not comply with GOST. If after 37 days the complaint is not given a move, the site generates an application to the prosecutor's office. Now the project has mobile app, and since 2015, the complaint is filled not by the user, but by the site team. At the time of writing, almost 86,000 holes have been added to the site, of which about 23,500 have already been fixed thanks to the efforts of users.

As for the fight against road defects not in the virtual, but in the real Russian space, in recent years it has turned into a kind of the new kind protest art: if at the end of the “zero” activists in different cities of Russia simply circled the road pits with bright paint, then a few years later they used them, for example, to create whole paintings depicting famous officials, and also planted plants in the potholes - bushes and small trees . However, this is a completely different story. And today's story, dedicated to how the followers of John Loudon McAdam disposed of his legacy, is over.

“Riding along the Russian highway is not very amusing” Prince Peter Vyazemsky. Almost 3 centuries have passed since the construction of the first Russian road, "all-weather and horse-drawn", connecting Moscow and St. Petersburg (1746 under Emperor Elizabeth), but for many settlements In Russia, unpaved roads remain "roads of life" to this day. Of the 900,000 km available in the country. roads, more than 150,000 km. are dirt roads. It is not always appropriate to recall the Russian mentality, “thunder thunder and pecking rooster”. "Primers" are available in Germany, famous for its autobahns, in the USA with their famous highways, Switzerland, Finland, Japan and other countries of the world.

Where are primers needed?

The construction of dirt roads is expedient on routes with low congestion, relatively cheap, but for all-weather operation it will require competent and constant “prevention”. They must be watered every summer with calcium chloride (for dedusting) and at least once a month they must be graded. In Finland, such "primers", subject to technology, serve for half a century.

It is technology that is still our “stumbling block”. For uniform spreading of gravel screenings (in Finland, for example), a special installation is used. Special equipment of this class is not produced in our country (let's hope that "for now"), they are brought and scattered by dump trucks, raked with a grader and rammed with a roller. To transport across the border and use Finnish or German equipment, you will have to pay such money that the dirt road will become “golden”.

By Russian SNiP A dirt road would be any road constructed with only soil or soil with additives (gravel, slag, etc.). It is a road of the 5th (lowest) class and can be either with road “clothes” - coating (also of the lowest class), or without it. They are divided into 3 classes:

1. Improved soil, with a road surface of sand and gravel, crushed stone, etc. The maps are marked in yellow.
2. Country soil (not improved). Just a “rolled” road, which, at best, is sometimes “stroked” by a grader. On the maps they are indicated by a solid line.
3. Field and forest dirt roads. In fact - 2 parallel "paths". On the maps they are indicated by a dotted line.

Useful advice: when driving on field and forest roads, try to move in such a way that the wheels are located on the side of the road and in the middle of such a road. Perhaps the "pioneer" of this route is a car with high ground clearance. Then “grabbing” something into the wheel will be much more harmless than running into an overgrown stump in the middle with a pallet.

Unlike forest, field and country roads, which appear according to the principle: “Where I drove, there is the road”, the construction of dirt roads with “clothing” begins with geological exploration of the area. Elevation differences (places of accumulation of precipitation), and soils of the area, and the possibility of further maintenance are taken into account. Depending on all these factors and the climate of the region, the type of road surface is selected and design estimates are prepared and agreed upon.

The construction of dirt roads consists of several stages:

• work on soil compaction, water drainage, preparation of a "trough";
• work on the construction of a "cushion" of the road foundation;
• laying and compaction and processing of the upper fabric (clothes).

Sandy dirt roads are built in places with the least autoload, almost for single cars. The upper part of the soil is selected, the “trough” is prepared, the soil and walls are compacted, which are covered with sand and rammed with a roller to the required degree. The disadvantages include the fact that, as a rule, does not rise above the landscape and is subject to erosion by storm flows and destruction by heavy equipment.

Useful advice: it should be remembered that the application of road markings on a dirt road depends on the sense of humor of the “road builders” or the “high-ranking” persons passing nearby and is not subject to compliance.

The crushed stone road is being built where the traffic of cars is already much more intense than on the "sand" and the weight of the equipment is more significant. The construction of such a road should include three stages and crushed stone should be used in 2 different fractions (fraction in French - part, share). The bottom layer in the prepared "trough" is a large crushed stone 40x70 in size and the top layer with a fraction of 40x20. If these conditions are met, then the effect of “wedging” is created (the introduction of smaller particles into the medium of large ones), which contributes to the compaction of the road jacket.

From ASG (sand-gravel mixture), road construction is carried out mainly in the area of ​​\u200b\u200bcottage buildings due to the cheapness and speed of construction. The technology is similar to the above: "trough", base and shirt. Minus - instability to the effects of water and temperature, hence fragility.

Useful advice: when driving on dirt roads, you should remember that the load on the chassis of your car will pass “painlessly” only if you follow Golden Rule: more hole - less speed. Otherwise, recklessness is fraught with wear of rubber-technical parts and failure of suspension elements.

The construction of a layered road of crushed stone and sand is most appropriate in most climatic zones of our country. The sand will create the necessary drainage for water removal, and the crushed stone layer will provide the necessary compaction that even trucks can withstand. As with any paved road, patching is necessary, adding crushed stone of various fractions in places where potholes have formed. The construction technology is similar to those previously listed, while this type of road will adequately withstand frost and show good moisture absorption during precipitation.

Soil strengthening methods

There are many methods by which it is possible to strengthen the soil:

• granulometric additives (crushed stone, sand, loam, gravel, etc.);
• organic binders in you (tar, bitumen, emulsions, resins);
• mineral binders (sodium silicate, lime and cement);
• salt solutions (sodium and calcium chloride, etc.);
• soil treatment with electrochemistry (direct current transmission with the help of electrolytes);
• heat treatment (burning of soil on local fuel);
• complex soil treatment.

Dirt roads with soil stabilization.

Modern construction technologies make it possible to turn simple crumbly soil into a monolithic canvas reinforced with a stabilizer. Widely roads with soil stabilization began to be built in the West in the 80s, although work in the direction of giving the soil other properties has been carried out since the 20s of the last century in our country. Back in 1926, soil liming was carried out in the USSR, but due to instability to frost, it was recommended only for the bases of the roadway. In the United States, country roads were built using cement-soil technologies.

The essence of the modern idea of ​​stabilization is simple: in the normal state, soil molecules are held together by the forces of electrostatic and chemical interaction. The soil is treated with a chemical substance (stabilizer, modifier) ​​that replaces anions (OH) in molecules, the forces of mutual attraction increase. Modern developments of stabilizers by Russian specialists (ANT technology - ant) ​​are limited only by the weight of equipment for road compaction. If it were physically possible to increase the ramming pressure by 5 times, then the strength of the resulting road would correspond in hardness to M200 concrete.

For construction, the soil already available on site is used, which entails significant savings, and the strength of such a dirt road is 3-5 times higher than that of an untreated one.

The top layer of soil to a depth of 20-30 cm is loosened and crushed with a cutter. The amount of sealant and additives (possibly grouting) is determined, which are required per sq.m. roads. A stabilizer is introduced into the soil by re-mixing with a cutter and the soil moisture is brought to the optimum (at which the forces of the electrochemical action of the soil molecules will be maximum) and in this state the soil is compacted with a roller. In case of insufficient moisture, the soil is irrigated with water from irrigation equipment.

Modern stabilizers allow mixing with fresh or salt water. The top layer hardens completely in 1 to 4 weeks, but traffic on it is already possible in just 2 hours after compaction.

The benefit is obvious:

• the properties of "adhesion" of the soil remain for a very long time;
• modification or stabilization suitable for any kind of soil;
• the treated (modified) soil can be stored separately at the construction site, ready for use (before compaction);
• minimal damage to the environment and landscape;
• in case of damage to the road “shirt” of stabilized soil, there will be no broken pieces (as in grouting) that can lead to accidents on the road.

Soil stabilizers chemical, organic and synthetic are constantly being improved. The scope of their application is becoming wider. From strengthening the banks of reservoirs and building stadium tracks to the production of bricks from the ground and the construction of airfield strips.

Conclusion

Whatever the dirt road, for its operation at any time of the year, it needs maintenance. Timely removal of dust and snow drifts, a competent and constantly clean drainage system, all this is necessary for safe movement and durability of any road. Whichever of them you have to travel, remember to comply with traffic rules and safety measures. Neither a rod to you, nor a nail!

Building a federal highway is a very expensive process. Only the state can afford to build such a road. The cost of one kilometer can reach several hundred thousand dollars. It is scary even to imagine how much such a road between distant points would cost.

Due to the fact that the construction of such roads is controlled at the highest government level, it is customary to approach their construction with great responsibility. The construction of federal roads, like other roads, can be divided into several stages. Let's look at each stage in more detail.

Project documentation

Like the construction of any other facility, the construction of a federal highway begins with project documentation. To get a complete project for construction new road it will take a lot of time. In some cases, this takes several months. The project must necessarily contain a clear binding of the entire road to specific geographical points. Only after the project is ready, you can proceed to the phased planning of construction work.

Preparatory work

The first stage in the construction of a federal highway is the clearing of the territory from objects that interfere with construction. On the territory where the construction is planned, trees are cut down, various network engineering(power lines, various pipelines). Eliminate any mechanical interference.

Excavation

Most do not attach much importance to earthworks, but these works are the most basic. The service life of the future road depends on the quality of the earthworks carried out.

All earthworks can be divided into the following stages:

• Soil excavation and filling. All roads, especially federal ones, should be on a kind of elevation. For this reason, in the lowlands, it is necessary to fill the base, and excavation is carried out on the hills. Excavation is carried out using excavators and. Soil is transported using dump trucks. As for adding soil, clay or sand is used for these purposes. But, in no case should you raise the level at the expense of black soil. This type of soil rots and sags after a while. It is worth noting that it is necessary to raise the level in layers. Each layer must be carefully tamped with special ones. If at this stage the technology is violated and the foundation of the road is poorly compacted, then the road in this place will be regularly destroyed due to subsidence of the foundation.
• drainage system. Any federal highway without fail, must be equipped. This system allows you to quickly remove water from the road. Most drainage systems are ditches and ditches along roads. Are being built drainage systems using excavators and loaders. Excess soil is removed by dump trucks.
• sand cushion. Regardless of what soil the base of the road consists of, the first layer should be a sand cushion. The layer of sand is usually from 15 to 30 centimeters. However, this layer can be changed depending on the type of soil. The sand cushion, subject to all construction technology, is laid on the geotextile material. The sand cushion is leveled using excavators and graders. This layer must be perfectly even. After leveling, the sand layer is necessarily compacted. Compaction is carried out by rollers of various configurations and capacities.
• crushed stone layer. The next layer of the road base consists of crushed stone of different fractions. The first layer of crushed stone is laid, like the sand layer, on geotextiles. It is worth noting that the lowest layer should consist of crushed stone of a rather large fraction. The second layer is crushed stone of the middle fraction. The last layer is crushed stone of fine fraction. In most cases, the crushed stone layer consists of three layers of crushed stone, but the number of these layers, as well as their thickness, is calculated individually for each road and each location. Crushed stone for the road base is delivered with the help of large-sized dump trucks with a large carrying capacity. Crushed stone layers are leveled with the help of excavators, backhoe loaders and motor graders. The last layer of crushed stone, which has the smallest fraction, is subject to mandatory compaction. This layer is compacted with special rollers.

Asphalting

Almost the last stage of construction is the process of laying asphalt pavement. Asphalt is being laid modern technologies, only with the help of special machines - asphalt pavers. This special equipment allows you to lay asphalt in a perfectly even layer. In addition, asphalt pavers allow you to adjust the layer of asphalt pavement with millimeter accuracy. This is simply an indispensable technique for road construction.

Immediately after laying the hot layer of asphalt, it must be carefully compacted. Asphalt is compacted with large and heavy rollers. This is done to achieve the maximum compaction effect. The denser the asphalt pavement, the better it will retain water. And this guarantees a longer life of the roadway.

Final work

After asphalting a new road, it is not immediately opened for traffic road transport. The final work must be done first. Such works include marking, installation of fenders, dividing strips and road signs. Only after all such works have been carried out, the road can be opened for general use.

Which companies are engaged in the construction of federal highways?

Today, there are practically no companies that could independently carry out the construction of a new federal highway of great length. In most cases, a general contractor is hired for such work, which, in turn, attracts subcontractors to the construction. This is done for the reason that for rapid construction, it is necessary to have very a large number of special equipment. No other company has such a large number of equipment on its balance sheet at the same time.

Our company very often acts as a subcontractor during the construction of federal roads, since we have a fairly large amount of special equipment available. All our commitments are carried out clearly on time in compliance with all standards and norms.