At first glance, the construction of a new highway seems to be a fairly simple task. To be honest, few people know who is working on the construction of roads, and what the planned amount of work needs to be done when the highway is being laid. Many people think that the main work is asphalting the road surface. This is wrong.

Who builds roads?

The organization that is directly involved in the construction of the highway is called the general contractor.

The workers of the road construction team perform earthworks: leveling the soil, laying a layer of sand, a layer of gravel and crushed stone.

Without specialized equipment, road construction would be unrealistic. In road construction, various drilling machines, excavators, bulldozers, tractors, asphalt pavers and uprooting machines are used.

How are roads built?

Before a new freeway can be built, it must be designed. The duties of engineers include forecasting the composition of the traffic flow (trucks, cars and buses) and the intensity of the traffic itself on this road. Thanks to the results of the forecast, it will be revealed how wide the future road will be, respectively, the number of lanes, as well as the thickness of the asphalt pavement layer and the base layer.

The surveyor must obtain information about land work. Work on the motorway will be carried out where the amount of earthwork will be minimal. The surveyor must take into account the soil composition. If loamy and clayey soils prevail at the site of the highway, then these types of soils will be very mobile in spring, since the soil is oversaturated with moisture.

After the design phase, the construction phase begins. The terrain on rough terrain is the most acceptable, because the soil that is in the hills is moved to the lowlands. The profile of such a pavement will contain a much smaller difference in elevation, and the cost of moving the soil will be minimal.

What materials are used in road construction?

After leveling the earth cover, lay out a layer consisting only of sand. Such a layer provides greater stability and immobility of the future motorway. Road builders lay a layer of sand because it has high performance in high humidity. It is the least subject to shifts when wet and when exposed to landslides. Sand is well compacted and laid with the help of equipment.

After a layer of sand lay out a mixture of gravel and sand. A layer of rubble is laid on top of this mixture. This strengthens the base. Crushed stone consists of stones that give the base the necessary hardness and strength. As well as a layer of sand, layers of gravel, sand and crushed stone are subjected to dense compaction.

Asphalt concrete pavement should have two layers. The bottom layer consists of large particles, and the thickness of this layer is 10 centimeters or more. The top layer of the asphalt pavement has a thickness of 5 cm. The top layer provides protection for the bottom layer and low noise. The upper layers of the pavement are reinforced with a geogrid of various types of asphalt concrete.

According to the editors of the site, the process of building roads is very complicated, in which each stage must be carefully worked out so that there would be one less problem in Russia.
Subscribe to our channel in Yandex.Zen

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. It will take a long time to get a full-fledged project for the construction of a new road. 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 engineering networks (power lines, various pipelines) are shifted to the side. 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. Drainage systems are being built 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 laid using 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 the new road, it is not immediately opened to traffic. 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 a very large amount 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.

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.)
• earthworks (removal or importation of soil, strengthening of the subgrade, construction of earthen embankments, etc.)
• laying of new or re-laying of existing engineering communications falling into 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 an asphalt mixture is distributed on the prepared subgrade base (stone or reinforced concrete "skeleton"), then it is "tread 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 to jumps temperatures do not crack. 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.

Roads have become one of the most important inventions of civilization. Even today, highways built centuries ago define the modern transport network of different countries. At all times, special attention was paid to the construction of roads - after all, it is always expensive and difficult. At least that was the case until recently. Thanks to high technology, even the highway can be "spread out" in a matter of days.

There is an opinion that the road is something engineering structure, which is being built for a long time, especially when it comes to achieving high level quality. This opinion is largely true. It's worth seeing.

Rapid road construction in Australia

It is still possible to build roads with high quality and at the same time quickly. Let do it modern technologies. In this video, you can see how 5 km of the highway are being laid in just 2 days. True, it is worth emphasizing that the conditions in Australia are still not the same as in Russia, and therefore it is easier to build roads there.

Paving stone in Holland

Another thing is Holland, where the conditions are much closer to those in Russia. There, the laying of paving stones was put on stream. Here are some of the wonders modern technology can do. The most important thing is that it turns out not only quickly, but also with sufficient quality.

Road repair in Canada

And this way you can repair the road in less than one day. First, the old asphalt is removed, then the site is cleaned, after which the new asphalt is laid. Where is this magic done? In Canada.

Railway construction in China

It is possible to quickly build not only roads, but also railway lines. This video was filmed in China, in the city of Longyang in the south of the country. Line segment railway installed in just 8 hours. In fairness, it should be noted that the Chinese took it not so much with high technologies as with the number of people involved. 1,500 specialists from 7 teams and 23 excavators worked at the site.

Portable military road

Finally a video that will showcase the most fast way creating a road in conditions of absolute off-road. True, such a road will be temporary, and they are traditionally used by the military.

If we talk about really cool projects in construction, then we cannot fail to mention - an architectural masterpiece that runs 16 km. above and below water at the same time.

Having traveled from Moscow to Vladivostok, we wrote a lot about roads. From complaints about the climate, corruption and crooked hands, I would like to move on to a more constructive analysis of the situation. There is a whole range of problems here: from non-compliance with technology, to poor-quality repairs. The big problem for roads is the overloaded transport. In Russia, almost all trucks are overloaded. This is done to make money faster. Overloaded trucks quickly break the layer of rubble at the base of the road, break down on the road, and cannot drive up the slope. The Ministry of Transport prohibits the movement of trucks on some routes in the summer, but life cannot be stopped!

What are roads made of?

Road construction is expensive and difficult. The road itself is a complex engineering structure, from which we see only the upper part: the coating, and the curbs. The road itself is a layered cake. The task of the complex road structure is to redistribute the loads from the machines to the ground. Depending on the design of the road, there are rigid cement concrete, and non-rigid asphalt concrete.

Cement concrete roads

At a cement concrete road, cement serves as a binder. The main advantage of a rigid cement concrete road is its durability. When used correctly overhaul cement concrete roads need only 24 years, and asphalt roads need it 10 years (and even then, subject to the technology).

In the late 60s, the USSR began to actively engage in cement concrete roads. But there was not enough cement, mass housing construction was going on. But oil was cheap and new deposits were discovered and technologies for the construction of asphalt concrete roads began to be developed. However, cement concrete managed to become widespread in the North and Siberia as a base for the construction of roads, and these roads are still standing.

There are two options for the construction of roads from cement concrete. The first is monolithic concrete, embedded in the workpiece and hardening in natural conditions. The second prefabricated from reinforced concrete slabs. Monolithic concrete is cast on site. However, in Russia, normal conditions for concrete hardening can be provided in a fairly short summer period, when the ambient temperature is at least 15-17 C. The monolithic technology for making concrete directly on the highways greatly limits the speed of road construction and large-scale construction in Russia is difficult. The second way to build roads from cement concrete is to assemble roads from factory-made prestressed concrete slabs. Factory conditions make it possible to obtain much better concrete with specified characteristics that are unrealistic to obtain in the field.

Many such roads were built earlier in Russia. Recall that the Moscow Ring Road used to be built of concrete slabs and was called "concrete" (now they still continue to call the Big and Small Rings in the Moscow Region). However, the old technology had a significant drawback: the slabs moved apart, because they required such a base that at one slab did not settle relative to the other. Especially this problem arose during the operation of the tracks by heavy vehicles.

Assembling the road from precast concrete. Visible channels and grooves

Today the problem of foundation is completely overcome. Reinforced concrete slabs for roads are equipped with through channels in the middle part with a diameter of 15-25 mm and tongue-and-groove side faces. Steel cables are pulled through the channels, which are coated with a protective lubricant that provides them with protection against corrosion, and the prestressing reinforcement is located in polyethylene tubes. Due to this, the prestressing reinforcement is provided with free movement, both in the process of tension and during the operation of the structure. A sealant is placed between the ends of reinforced concrete slabs. The cost of such roads according to the new technology is on average two times lower than that of asphalt concrete roads, since the cost of preparing the foundation is radically reduced.

In the US, 80% of road surfaces are cement concrete. Asphalt is used only as an upper softening layer for traffic. The United States first used this technology in 1921. Today in the United States, thousands of "eternal" roads and pavements are built from precast prestressed concrete. Belgium built its first stretch of road in prestressed concrete in 1950 and has been using the technology extensively since 1970. Moreover, not only highways are being built, but also roads of the regional and local importance. In France, this technology was first used in 1947, and began to be introduced everywhere since 1983.

Video on how to repair a cement concrete road

asphalt concrete

Now in Russia there are only 2-3% of hard concrete roads, in Germany - more than 40%, and all new roads being built in our country are asphalt. Perhaps because bitumen for asphalt is a serious source of income for the oil business.

Road construction with asphalt concrete (soft) surface

The lowest layer - the base layer - is soil, the next layer is sand, then comes crushed stone and the last top layer is pavement - or asphalt. When the asphalt is destroyed, cracks and small holes appear on the road, which interfere with movement, but, as they say, "not fatal." In any case, asphalt concrete is a complex mixture of bitumen, concrete and filler. The durability of the layer depends on the quality of the ingredients, so road workers check the coatings by taking out samples of asphalt.

Video how to make asphalt for roads

Road foundation

A good foundation is the key to a good road. Depending on the upcoming mode of operation, the thickness of the crushed stone base, the number of layers and the size of the crushed stone are selected. When laying, each layer of crushed stone must be compacted with a roller. To improve the quality of the seal, the base is shed with water. The father of my friend from Kaliningrad (Königsberg) recalled. that before laying the paving stones, the Germans shed the foundation for a very long time. These roads then stood for 40 years without repair.

Geogrids and geotextiles

However, even a well-laid base sags: crushed stone goes into the sand, and the sand mixes with the soil, a rut appears in the upper layer, and pits form on the road.

Potholes on the road from heavy truck traffic

To avoid this, they came up with reinforcing and separating the layers of the road. In the 70s of the 20th century, needle-punched geotextiles were invented (in the USSR it was called Dornit). This material was used at the border of the soil with sand and did not allow these layers to mix, in addition, drainage properties were used in the geotextile, and it was able to remove water from the roadbed. At that moment it was a breakthrough technology.

It seemed that she solves the problem of low-quality roads once and for all. But over time, the load on roads has increased and the use of geotextiles has become insufficient. Then they began to use a flat plastic geogrid between the layers of sand and gravel. This technology gives the effect of "jamming and fixing". Crushed stone falls into the grate and creates a very dense layer. Such a layer is much less susceptible to dynamic loads in various planes.

The geogrid at the base of the road securely holds the crushed stone layer

Construction using new materials received in developed countries ubiquitous distribution. So, in Canada, a country with similar climatic conditions to Russia, geotextiles are used on more than 90% of federal roads, geogrid - on more than 60%. In the US, the picture is similar. In Germany, in general, almost 100% of asphalt roads are built using geotextiles and more than 80% of roads with additional geogrid reinforcement.

In the last decade, China has begun to actively develop its infrastructure, and geomaterials are also actively used there. How are things in Russia? In 2011, in the Russian Federation, on federal roads of the 1st and 2nd category, geotextiles were used in less than 50% of cases, and a flat geogrid - in less than 10% of cases! In fact, we continue to build roads using the technologies of the last century.

Coating laying

After the base of crushed stone is laid, it is shed with special resin mastic and proceed directly to asphalting. The thickness of the asphalt concrete pavement, as well as the thickness of the crushed stone base, depends on the intensity of the planned operation. For the adjacent territory of an ordinary residential high-rise building, where the movement of trucks is not planned, you can perfectly manage with one layer of fine-grained asphalt 4-5 cm thick. For more serious conditions, it is necessary to lay two layers of asphalt - the lower layer of coarse-grained asphalt concrete 4-5 cm thick, and the upper from fine-grained also 4-5 cm. The third layer of asphalt is laid for especially busy roads. For especially busy roads, a reinforcing metal mesh is laid under the asphalt, which redistributes the load in the upper layer. Asphalt layers are bonded together with bituminous mastic.

Asphalt mix is ​​prepared at asphalt plants. By and large, this is a huge mixer that mixes the asphalt concrete components and heats them up. Plants are often made mobile to reduce mix delivery time as the mix is ​​stacked hot.

Usually, the mixture is delivered to the facility by dump trucks. . From 1 ton of asphalt, an average of 10 m2 of asphalt concrete pavement 4 cm thick is obtained. So, asphalt is brought in, then manually or using special machines - asphalt pavers - distributed over a given area, leveled, planned and compacted using rollers, vibrating plates, rammers.

The process of laying asphalt depends on the weather. Do not lay asphalt in heavy rain. In addition, the asphalt mix is ​​a hot product. In a hot state, it is shipped at an asphalt concrete plant and as soon as possible, without letting it cool down, it needs to be transported, unloaded, and rolled. This is especially true for the cold season.

My father told how, after the war, as a boy, he ran through the streets and watched how German prisoners worked. One of them, apparently an engineer, was engaged in asphalting roads. More precisely, he led the process. Somehow a dump truck with asphalt drives up. The German took a thermometer out of his breast pocket and put it in the asphalt and said to the driver:
- The temperature is two degrees below the permissible, I will not put it.
- Oh, you filthy Fritz! I drove you to Berlin, but now I will strangle you on the spot!
— I will not use this asphalt. You stopped somewhere along the road, drank a beer. The asphalt is cold. If I put it down, it will peel off in six months, crumble. Do what you want…
The driver spat, trampled, and left.