Types of asphalt repairs: what specialists offer. Modern methods and means of patching road surfaces Road repair in winter

If the asphalt is laid according to all the rules, then it should last more than one year. But that's in theory. In our life, everything is different. As a rule, the first pits on the roads appear within a few months after the road surface is renewed.

Why it happens? The main reasons, of course, are negligence and violation of asphalt paving technology. For the sake of economy, road workers (they want to get more money and spend less) add less bitumen emulsion to the mixture, save on sand and gravel. Because of this, the asphalt becomes brittle and, as a result, kinks, cracks and pits appear.

Current regulations do not allow road services to wait for good and comfortable weather to carry out repairs. Judge for yourself, the existing GOST R 50597–93 “Roads and streets. Requirements for the operational state permissible under the safety conditions road traffic»The maximum permissible dimensions for holes on the roads have been set: along the width of the road - no more than 60 cm, along the length - 15, in depth - 5.

And in case of identifying problem areas, immediately inform the road workers. Those, in turn, are obliged to promptly repair the roadway. After all, if a car falls into such a hole, it is the organization serving this section of the road that will have to answer.

That is why, in spite of rain and snow, asphalt rolls into holes. Indeed, according to the standards, the elimination period is a maximum of 10 days. Is it correct?

Road works for laying asphalt (including during patching) are carried out in accordance with SNIPs and GOSTs. When repairing a pit, they usually use cold way styling. In this case, the asphalt mixture sets very quickly and almost immediately you can drive over the repaired area.

There is also a hot way. It is mainly used in the construction of new roads and the reconstruction of old ones. Here they use a hot bitumen mixture and roll it until it cools completely. Occasionally, hot styling is also resorted to during patching. More often in warm weather, when the temperature outside is not lower than 10 ° C. However, there are so-called cast mixes that allow hot styling even at sub-zero temperatures. This mixture is brought to the place of repair in a special thermos trailer. The composition is in a liquid state, like thick glue. The temperature of the mixture is under 200 ° C. Observing the technology, it can be laid even in harsh winter conditions... The high temperature simply evaporates moisture from the pit. After the mixture hardens, the road section can be used. This pleasure is quite expensive. Therefore, this type of repair is used in case of serious damage to the canvas, when it is required to quickly restore movement in the emergency section.

So, if hot styling is used in the warm season (+ 10 ° C and above), cold styling is limited to slight frosts (not lower than -5 ° C), and cast mixes are more suitable for colder temperatures, already at -10 ° C, for example. It is clear that, if necessary, road workers will patch the road even at lower temperatures. If a hole suddenly forms on the highway (a rift, etc.), traffic is blocked, and outside minus 30, you will not wait for the spring warming. In general, any winter asphalt paving repairs are, in fact, emergency. Their task is to make sure that the repaired area lasts until the heat, when you can start restoration seriously.

As you can see, roads can be repaired in winter as well. The main thing is to comply with the technology. That's just in our realities about high-quality repair few people think about roads. Indeed, for most road services it is more important to have a good and constant income from road repair and maintenance. If you do everything efficiently, you won't get money from the budget. The problem is that we have not yet established guarantees for the service life of the road surface. If there was such a period, the road workers would eliminate all the holes at their own expense. And so they built a road, got money. Potholes appeared - they patched it up, got the money again. As a result, we are simply doomed to drive through pits and potholes.

Well, for example, a few numbers. Last year, it was spent on repairing the road and street network: in Kazan - 2.87 billion rubles, in Vladivostok - 2 billion, in the Moscow region - 12 billion, in the capital - 22.4 billion. This is for comparison. Now imagine how much could have been saved if the roads after laying (reconstruction and major repairs) did not require repair for at least four years.

Why repair roads in winter? Many Volga residents are often perplexed: "Why can't we wait for spring and is it necessary to patch roads in winter?" As it turns out, there are good reasons for this. First of all, to keep the roads until spring, so that later there will be something to repair. Of course, patching is not a panacea: it cannot replace a full-fledged repair with maps. But on the other hand, it allows you to carry out at least emergency work and prevent large-scale destruction. In addition, today there is a special, "safe" laying technology for winter repairs - with cast asphalt concrete. It can be used to repair roads not only in wet weather, but even at subzero temperatures.

What is cast asphalt?

Cast asphalt concrete is a mixture of bitumen and mineral powder, heated in special conditions up to a temperature of 200-250 degrees. It is one of the "gost" types of asphalt concrete (GOST R 54401-2011). Cast asphalt differs from ordinary asphalt by its special elasticity, while maintaining its strength and elasticity. Due to these properties, "casting" can be used even at severe subzero temperatures - up to -20 degrees. And when poured asphalt is poured into a puddle, the residual moisture is evaporated together with the boiling mixture. Therefore, he is not afraid of rain, snow or frost. For comparison: working with ordinary asphalt is problematic even at "zero".

When exactly is it time to repair the pit with cast asphalt?

In order for the pit to be in the focus of attention of the road workers, it must have certain parameters: 60 centimeters in length, 15 centimeters in width and 5 centimeters in depth. Or in short: "60-15-5". However, the Volga road workers say that in this sense they are working "ahead of the curve":

- We do not wait until the pit reaches the "gost" parameters, but we make patches much earlier, - says Pavel Tselkovsky, director of the MBU "Combine of Improvement".

It turns out like a dentist: it is better to cure small caries and put a filling on time than to lose the whole tooth later.

Why do small pits turn into large ones before being repaired?

As the road workers explain, not only the pit itself is being repaired, but also the entire area of ​​the “lesion”, including the cracks around it. As a result, the area of ​​the pit after milling can be many times greater than the initial parameters. However, in such a "semi-finished" form, according to the assurances of the road workers, the pit stays no more than 1 day. Then it is poured with cast asphalt.

How is the repair done with cast asphalt?

Of course, the pits are pre-prepared for repair with cast asphalt concrete. So, the asphalt is milled and blown out of excess dust and debris. A heated mixture of asphalt is poured into the pit. Even if there is liquid in it, cast asphalt is not afraid of water. In this case, part of the liquid is displaced naturally, and the rest is evaporated due to the high temperature of the "casting". The poured mixture is leveled by road workers manually. Freezes new asphalt fast enough - from 20 minutes to 1 hour.

How long are cast-repaired roads?

Of course, patching is not a panacea for roads. But in winter, in the absence of card repair, it is the only possible one. According to the observations of the "Combine of Improvement", which has been working with cast asphalt for more than 10 years, the quality of such patches is quite high - they last for at least 5 years. So, patches made with cast asphalt in the past years feel great today. These are, for example, last year's patches at the hydroelectric power station and on Kommunisticheskaya Street, as well as more "older" patches at the intersection of Stalingradskaya Street and Lenin Avenue. Let us also recall the "demonstrative" repair of asphalt laying directly "into a puddle" on Sovetskaya Street a couple of years ago ().

Why are patches installed in some areas from year to year?

At the same time, there are some problem areas where patches have to be laid more often. For example - the road on the bridge crossing of the Volzhskaya HPP. The destruction of asphalt here is associated with a number of factors, and sometimes it seems easier to re-shift the entire site.

Pavel Tselkovsky:

- For many years there have been three problematic sections of the road at the hydroelectric power station - patches have to be installed on them every year. The reasons lie in the incorrect location of storm water, a large flow of heavy trucks and the mobility of the asphalt road, which leads to faster destruction in these areas.

How many roads will be repaired in Volzhsky this winter?

The Volga road builders postponed road repair with maps until spring. But the repair with cast asphalt in the city is in full swing, but "to the point": where there is a need for patches. By the middle of winter, Volga road workers repaired about 2.5 thousand by "casting" square meters asphalt. Among the main streets on which patches appeared are Kommunisticheskaya, Pushkin, Karbyshev, Aleksandrov, Kirov, Karl Marx, Volgodonskaya, 40 Let Pobedy streets, as well as sections of the road through the hydroelectric power station. In total, the road workers intend to repair about 9 thousand square meters of roads with cast asphalt this winter.

“Thanks to the prompt repair with cast asphalt, there are almost no emergency pits in Volzhsky today,” says Pavel Tselkovsky.

How are roads being repaired outside Volzhsky in winter?

For the first time, cast asphalt concrete was laid in Lyon, France, almost 200 years ago - in 1829. Today, repair with cast asphalt is practiced by many Russian cities and not only large ones. In Europe, some motorways are generally completely repaired using the cast asphalt technology. Such repairs are more expensive than usual, but more durable. For example, in the Czech Republic, patching is allowed only as a temporary and compulsory measure. After a couple of weeks, the section of the road with patches must be completely repaired, laying 100% new coverage. At the same time, there are no joints either - they are heated with a special burner to a plastic state, and motorists do not feel any changes.

In order to avoid having to fill the holes with crushed stone or broken bricks in the spring, as is often done in our country, it is necessary to carry out winter road repairs. Mainly road repairs in winter period involves the repair of holes, the restoration of the entire roadway is very rare.

Unfortunately, this is only a temporary remedy that does not allow achieving a "long-lasting" effect, but for most roads this is a forced measure.

Carrying out works of this nature often depends on regional characteristics. Important criteria are the duration of the winter period, the degree of soil freezing, the absolute value of negative temperatures. The amount of frozen soil in the embankment should not exceed 70%, and its maximum permissible size is more than 20-30 cm. The permissible height of the subgrade during work carried out at a temperature of -20 ° C should not be more than 2.5 m, while at -5 ° С - the height is not limited.

The method of laying hot asphalt concrete with high-quality work allows you to repair pits and potholes for more long term... To do this, the pothole must be warmed up, cleaned, primed and asphalt laid. An important point, subject to which the desired effect can be achieved is maintaining the required temperature level of the asphalt (from + 80 ° С).

A good effect can be achieved by using cold mix... Instead of viscous bitumen, it uses more elastic analogs, the viscosity of which increases with decreasing temperature. A special additive is introduced into such a mixture, which does not allow the material to harden quickly. Cold mix can be laid at a temperature not lower than + 5 ° С. When working with this material, the lower permissible threshold for carrying out work is -25 ° C. Such a patch will behave well on roads where there are no traffic jams, at intersections and stops - there will be little benefit from such repairs. Cold mixtures have little shear resistance. If the road has a high degree of cross-country ability, then the repaired section can be immediately released into operation - the machines will only compact the asphalt, which will make it more durable.

Another option is cast asphalt... The hot doughy mixture of high viscosity bitumen is transported in special boilers or coppers. The laying temperature must be at least + 200 ° С. As it cools, the mixture hardens and compacts by itself, even without using a roller.

Basic requirements for asphalt pavements in winter:

1. Increase in the thickness of the styling by 1 cm, the total thickness is not less than 5 cm.
2. An increased content of bitumen is required in the mixture used.
3. Carrying out works in the absence or weak wind.
4. Intensive material supply for paving by dump trucks with insulated bodies.

The task of patching is to restore the continuity, evenness, strength, adhesion and waterproofness of the coating and ensure normative term service of renovated sites. For patching, various methods, materials, machines and equipment are used. The choice of one method or another depends on the size, depth and number of potholes and other defects in the coating, the type of coating and materials of its layers, available resources, weather conditions, requirements for the duration of repair work, etc.

The traditional way provides for cutting the edges of the pothole to give it a rectangular shape, cleaning it from asphalt concrete scrap and dirt, priming the bottom and edges of the pothole, filling it with repair material and compaction. To give the pothole a rectangular shape, small cold milling machines, circular saws, and perforators are used.

As a repair material, asphalt-concrete mixtures that require compaction are mainly used, and from mechanization equipment, small-sized rollers and vibratory rammers are used.

When working in conditions of increased moisture, the potholes are dried before priming compressed air(hot or cold), as well as using burners infrared radiation... If the coating is repaired with small maps (up to 25 m 2), the entire area is heated; when repairing with large maps - along the perimeter of the site.

After preparation, the pothole is filled with repair material, taking into account the seal margin. At a depth of potholes up to 5 cm, the mixture is placed in one layer, more than 5 cm in two layers. Sealing is made from the edges to the middle of the areas to be repaired. When filling potholes deeper than 5 cm, a coarse-grained mixture is placed in the lower layer and compacted. This method allows you to get a high quality repair, but requires a significant number of operations. It is used in the repair of all types of coatings made of asphalt concrete and bitumen-mineral materials.

Shallow potholes up to 1.5-2 cm deep on an area of ​​1-2 m 2 or more are repaired using the method of surface treatments using fine crushed stone.

The repair method with heating the damaged coating and reusing its material is based on the use of special equipment for heating the coating - an asphalt heater. The method allows you to obtain a high quality of repairs, saves material, simplifies the production technology, but has significant restrictions on weather conditions (wind and air temperature). It is used in the repair of all types of coatings from asphalt concrete and bitumen-mineral mixtures.

The repair method by filling potholes, holes and subsidence without cutting or heating the old pavement consists in filling these deformations and destruction with cold polymer-asphalt-concrete mixture, cold asphalt concrete, wet organic-mineral mixture, etc. The method is notable for its simplicity of execution, allows to work in cold weather with wet and wet surfaces, however, it does not provide high quality and durability of the repaired coating. It is used when repairing pavements on roads with low traffic volume or as a temporary, emergency measure on roads with high traffic volumes.

According to the type of repair material used, two groups of patching methods are distinguished: cold and hot.

Cold ways based on the use of cold bitumen-mineral mixtures, wet organic-mineral mixtures (VOMS) or cold asphalt concrete as a repair material. They are mainly used for the repair of black crushed stone and cold asphalt concrete pavements on low-category roads, as well as when urgent or temporary potholes are needed at an earlier date on high-category roads.

Patching work in this way begins in the spring, as a rule, at an air temperature of at least + 10 ° С. If necessary, cold mixes can be used for patching and at a lower temperature (from + 5 ° C to -5 ° C). In this case, before laying, cold black crushed stone or cold asphalt concrete mixture is heated to a temperature of 50-70 ° C, with the help of burners, the bottom and walls of the potholes are heated until bitumen appears on their surface. In the absence of burners, the surface of the bottom and walls is coated with bitumen with a viscosity of 130/200 or 200/300, heated to a temperature of 140-150 ° C. After that, the repair material is laid and compacted.

The formation of a coating at the place of repair by a cold method occurs under traffic for 20-40 days and depends on the properties of liquid bitumen or bitumen emulsion, the type of mineral powder, weather conditions, traffic intensity and composition.

Cold asphalt concrete layers for patching are prepared using liquid medium-thickening or slow-setting bitumen with a viscosity of 70/130, using the same technology as hot asphalt concrete mixtures, at a bitumen heating temperature of 80-90 ° C and a mixture temperature at the outlet of the mixer 90-120 ° C. Mixtures can be stored in stacks up to 2 m high. summer period they can be kept in open areas, in autumn-winter period- in closed warehouses or under a canopy.

Repair work can be carried out at a lower air temperature; repair material can be prepared in advance. The cost of work using this technology is lower than with the hot method. The main disadvantage is the relatively short service life of the repaired pavement on roads with heavy trucks and buses.

Hot Ways are based on the use of hot asphalt concrete mixtures as a repair material: fine-grained, coarse-grained and sand mixtures, cast asphalt concrete, etc. The composition and properties of the asphalt concrete mixture used for repair should be similar to that of which the coating is made. The mixture is prepared according to the usual hot asphalt concrete preparation technology. Hot methods are used in the repair of asphalt-concrete roads. Work can be performed at an air temperature of at least + 10 ° C with a thawed base and dry coating. When using a heater for the repaired coating, it is allowed to carry out repairs at an air temperature of at least + 5 ° C. Hot patching methods provide a higher quality and longer service life of the repaired coating.

As a rule, all patchwork works are performed in early spring as soon as weather and coverage conditions permit. In summer and autumn, potholes and pits are repaired immediately after their appearance. Technology and work organization different ways have their own characteristics. However, for all patching methods, there are general technological operations that are performed in a specific sequence. All these operations can be divided into preparatory, main and final.

Preparatory work includes:

installation of fencing for work sites, road signs and lighting device, if work is performed at night;

marking of repair sites (maps);

cutting, breaking or milling damaged areas of the coating and cleaning the removed material;

cleaning potholes from residues of material, dust and dirt;

drying the bottom and walls of the pothole, if the repair is carried out with a hot method when the surface is wet;

treatment (priming) of the bottom and walls of the pothole with bitumen emulsion or bitumen.

The marking of repair sites (repair cards) is carried out using a stretched cord or chalk using a rail. The place of repair is delineated by straight lines parallel and perpendicular to the axis of the road, giving the contour correct shape and capturing the intact pavement 3-5 cm wide. Several potholes, located at a distance of up to 0.5 m from one another, are combined into a common map.

Cutting, breaking or milling of the coating within the marked map is performed to the thickness of the destroyed coating layer, but not less than 4 cm throughout the entire repair area. In this case, if the pothole in depth has affected the lower layer of the coating, the thickness of the lower layer with the destroyed structure is loosened and removed.

It is very important to remove and remove all the destroyed and weakened layer of asphalt concrete, capturing along the entire marked contour a strip at least 3-5 cm wide from durable, undisturbed asphalt concrete. These edge strips of potholes cannot be left unremoved, since the solidity of asphalt concrete is weakened here due to the formation of microcracks, loosening and spalling of individual rubble from the walls of the pothole (Fig. 13.10, a). In the pothole, water collects, which, under the dynamic action of the wheels of cars, penetrates into the interlayer space and weakens the adhesion of the upper layer of asphalt concrete to the lower one. Therefore, if you leave the weakened edges of the pothole, then after laying the repair material, after a while the weakened edges can collapse, the newly laid material will lose its connection with the strong old material and the pothole will begin to develop.

Rice. 13.10. Cutting the pothole before placing the repair material:
a - cutting of weakened places; b - cutting the edges of the pothole after milling;
1 - weakened pothole wall; 2 - exfoliated part of the coating; 3 - destroyed part of the pothole bottom; 4 - chopped off or beveled pothole wall

The walls of the edges of the pothole after cutting should be vertical along the entire contour. Cutting and breaking of the pavement can be done with a pneumatic chisel hammer or crowbar, a concrete breaker, a seam saw and a ripper, or with a road milling machine.

When using a pothole cutter, a rounded front and back pothole is created that must be trimmed circular saw or a jackhammer. Otherwise top part the laid layer of repair material at the interface with the old material will be very thin and quickly collapse (Figure 13.10, b).

The loosened material of the old pavement is manually removed from the pothole, and when using a road milling machine, the removed material (granulate) is fed by a loading conveyor to a dump truck and removed. The card is cleaned using shovels, compressed air, and when large area cards - with the help of street sweepers. Drying of the bottom and walls of the card is carried out if necessary by blowing with hot or cold air.

Binding (priming) of the bottom and walls of the potholes is carried out in the case of laying hot asphalt concrete mixtures as a repair material. This is necessary in order to ensure better adhesion of the old asphalt concrete material to the new one.

The bottom and walls of the cleaned card are treated with liquid medium-thickening bitumen with a viscosity of 40/70, heated to a temperature of 60-70 ° C with a flow rate of 0.5 l / m 2 or bitumen emulsion with a flow rate of 0.8 l / m 2. In the absence of mechanization means, bitumen is heated in mobile bitumen boilers and distributed over the base using a watering can.

Filling the pothole with repair material can only be done after all preparatory work... The laying technology and the sequence of operations depend on the method and amount of work performed, as well as on the type of repair material. With a small amount of work and the absence of means of mechanization, the laying of repair material can be done manually.

The temperature of the hot asphalt concrete mixture delivered to the place of laying should be close to the preparation temperature, but not lower than 110-120 ° C. It is most advisable to lay the mixture at a temperature where it can be easily processed, and during the laying process, waves and deformations are not formed during the passage of the roller. Depending on the type of mixture and its composition, such a temperature is considered: for a multi-gravel mixture - 140-160 ° C; for medium-gravel mixture - 120-140 ° С; for a low-gravel mixture - 100-130 ° C.

The mixture is laid in the card in one layer at a cutting depth of up to 50 mm and in two layers at a depth of more than 50 mm. In this case, a coarse-grained mixture with a crushed stone size of up to 40 mm can be laid in the lower layer, and in upper layer- only a fine-grained mixture with a grain size of up to 20 mm.

The thickness of the paving layer in a loose body must be greater than the thickness of the layer in a dense body, taking into account the safety factor for compaction, which is taken: for hot asphalt concrete mixtures 1.25-1.30; for cold asphalt concrete mixtures 1.5-1.6; for wet organic-mineral mixtures 1.7-1.8, for crushed stone and gravel materials treated with binder, 1.3-1.4.

When laying repair material in a mechanized way, the mixture is fed from a thermos hopper through a swivel chute or a flexible hose of large diameter directly into the pothole and evenly leveled over the entire area. Laying of asphalt-concrete mixtures when filling maps with an area of ​​10-20 m 2 can be done by an asphalt paver. In this case, the mixture is stacked over the entire width of the card in one pass, in order to avoid an additional longitudinal seam for mating the laying strips. Compaction of the asphalt concrete mixture, laid in the lower layer of the pavement, is carried out by pneumatic rammers, electric rammers or manual vibratory rollers in the direction from the edges to the middle.

The asphalt concrete mixture laid in the top layer, as well as the mixture laid in one layer with a pothole depth of up to 50 mm, is compacted with a self-propelled vibration roller (first, two passes along the track without vibration, and then two passes along the track with vibration) or light static smooth ring rollers weighing 6-8 tons up to 6 passes on one track, and then with heavy rollers with smooth drums weighing 10-18 tons up to 15-18 passes on one track.

The compaction coefficient must have a value of at least 0.98 for sandy and low-crushed asphalt-concrete mixtures and 0.99 for medium- and multi-crushed mixtures.

Compaction of hot asphalt concrete mixtures begins at the highest possible temperature at which deformations do not form during the rolling process. The seal must ensure not only the required density, but also the evenness of the repair layer, as well as the location of the repaired coating on the same level with the old one. For better mating of the new coating with the old one and the formation of a single monolithic layer when laying hot mixes, the joint along the entire contour of the felling is heated using a line of burners or an electric heater. The joints of potholes protruding above the surface of the coating are eliminated by milling or grinding machines. Final work is the cleaning of the remaining waste from the repair with its loading into dump trucks and the removal of fences and road signs, the restoration of marking lines in the patching area.

The quality of the repair and the service life of the repaired coating depend primarily on compliance with the quality requirements for all technological operations (Figure 13.11).

Rice. 13.11. The sequence of the main operations of patching:
a - correct; b - wrong;
1 - pothole before repair; 2 - cutting or cutting, cleaning and processing with a binder (priming); 3 - filling with repair material; 4 - seal; 5 - view of the repaired pothole

The most important are the following requirements:

repairs must be carried out at an air temperature not lower than the permissible for the given repair material on a dry and clean surface;

when cutting down the old pavement, weakened material must be removed from all pothole zones, where there are cracks, breaks and spalling; the repair card must be cleaned and dried;

the shape of the repair card must be correct, the walls are vertical, and the bottom even; the entire surface of the pothole must be treated with a binder;

the repair material must be laid at optimal temperature for this type of mixture; the thickness of the layer must be greater than the depth of the pothole, taking into account the margin for the compaction factor;

the repair material must be carefully leveled and compacted flush with the coating surface;

the formation of a layer of new material on the old surface at the edge of the card is not allowed to avoid jolts when a car collides and the rapid destruction of the repaired area.

Correctly performed repairs result in the height of the applied layer after compaction, exactly equal to the depth of the pothole without irregularities; correct geometries and invisible seams, optimal compaction of the laid material and its good connection with old coating material, long service life of the repaired coating. The result of improperly performed repairs may be unevenness of the compacted material when its surface is above or below the surface of the coating, arbitrary shape of the map in plan, insufficient compaction and poor connection of the repair material with the material of the old coating, the presence of protrusions and sagging on the edges of the map, etc. Under the influence of transport and climatic factors areas of such repairs are rapidly deteriorating.

Patching of black crushed stone or gravel pavements... When repairing such coatings, simpler materials and repair methods can be used, which make it possible to reduce the cost of maintaining roads with black-gravel and black-gravel coatings. Most often, these methods are based on the use of cold bitumen-mineral mixtures or materials treated with a bitumen emulsion as a repair material. One of these materials is a mixture of organic binder (liquid bitumen or emulsion) with wet mineral material (crushed stone, sand or gravel-sand mixture), laid in a cold state. When using liquid bitumen or tar, cement or lime is used as an activator.

So, for example, to repair potholes up to 5 cm deep, a repair mixture is used in the composition: crushed stone 5-20 mm - 25%; sand - 68%; mineral powder - 5%; cement (lime) - 2%; liquid bitumen - in excess of 5% weight; water - about 4%.

The mixture is prepared in forced mixers in the following sequence:

mineral materials are loaded into the mixer at natural humidity (crushed stone, sand, mineral powder, activator), mixed;

add the calculated amount of water and mix;

an organic binder heated to a temperature of 60 ° C is introduced and finally mixed.

The amount of injected water is adjusted depending on the intrinsic moisture content of the mineral materials.

When making a mixture, mineral materials are not heated or dried, which greatly simplifies the preparation technology and reduces the cost of the material. The mixture can be prepared for future use.

Before laying the mixture, the bottom and walls of the pothole are not primed with bitumen or emulsion, but are moistened or washed with water. The laid mixture is compacted and movement is opened. Final formation layer occurs under the traffic.

Patching using wet bitumen-mineral mixtures can be performed at a positive temperature not exceeding + 30 ° С and at negative temperature not lower than -10 ° С in dry and damp weather.

Patching repair of black crushed stone pavements by impregnation method... As a repair material, crushed stone is used, pre-treated in a mixer with hot viscous bitumen in an amount of 1.5-2% of the crushed stone mass.

After marking the contour of the pothole, its edges are chopped off, the old coatings are cut open and the loosened material is removed, the bottom and walls of the pothole are treated with hot bitumen at a rate of 0.6 l / m 2. Then black crushed stone of 15-30 mm fraction is laid and compacted manual rammer or a vibratory roller; bitumen is poured at a rate of 4 l / m 2; the second layer of black crushed stone of fractions 10-20 mm is laid and compacted; crushed stone is treated with bitumen at a rate of 2 l / m 2; stone screening of 0-10 mm fractions is scattered and compacted with a pneumatic vibrating roller. Using the same technology, repairs can be made by impregnation and using crushed stone not treated with bitumen. This increases the consumption of bitumen: at the first spill - 5 l / m 2, at the second - 3 l / m 2. The distributed bitumen permeates the layers of crushed stone to the entire depth, as a result of which a single monolithic layer... This is the essence of the impregnation method. Viscous bitumen 130/200 and 200/300 are used for impregnation at a temperature of 140-160 ° C.

A simplified patching method with impregnation of crushed stone with bitumen emulsion or liquid bitumen is widely used in France for patching small potholes on roads with low and medium traffic. Such potholes are called "chicken nests".

Repair technology consists of the following operations:

first, potholes or pits are manually covered with large crushed stone - 10-14 or 14-25 mm;

then, as it is filled, fine crushed stone of fractions 4-6 or 6-10 mm is scattered until the road profile is completely restored;

the binder is poured: bitumen emulsion or bitumen in a ratio of 1:10, i.e. one part binder to ten parts of crushed stone by weight;

compaction is done manually using a vibrating plate.

The binder penetrates into the crushed stone layer to the base, as a result of which a monolithic layer is formed. The final formation takes place under the influence of moving vehicles.

In addition to direct impregnation for patching, the reverse impregnation method is used. In this case, bitumen with a viscosity of 90/130 or 130/200, heated to a temperature of 180-200 ° C, is poured onto the bottom of the prepared card. The bitumen layer thickness should be equal to 1/5 of the pothole depth. Immediately after the hot bitumen spill, the mineral material is poured: crushed stone of fractions 5-15; 10-15; 15-20 mm, ordinary crushed stone or gravel-sand mixture with a particle size of up to 20 mm. The mineral material is leveled and compacted with a rammer.

When interacting with a mineral material that has natural moisture, with hot bitumen foaming occurs and the material is impregnated with bitumen from the bottom up. If the foam has not risen to the surface of the material, the binder is re-poured at the rate of 0.5 l / m 2, covered with a thin layer of crushed stone and compacted.

With a pothole depth of up to 6 cm, all its fillings are performed in one layer. At greater depths, filling is carried out in layers 5-6 cm thick. Patching works in this way can be performed even at negative air temperatures. However, the service life of the repaired sections in this case is reduced to 1-2 years.

Patching using crushed stone treated with a bitumen emulsion has a number of advantages: there is no need to warm up the binder to prepare the mixture; can be installed at a positive ambient temperature, i.e. from early spring to late autumn; rapid disintegration of the cationic emulsion, which contributes to the formation of a repair layer; no trimming, material removal and priming.

To perform the work, a car repairman is used, which includes: a base car with a thermally insulated tank for emulsion with a capacity of 1000 to 1500 liters; Switchgear for emulsion (compressor, hose, nozzle); crushed stone bins of fractions from 2-4 to 14-20. The cationic emulsion used must be rapidly disintegrating, contain 65% bitumen and be warm at temperatures between 30 ° C and 60 ° C. The surface to be treated must be clean and dry.

The technology for repairing deep pits over 50 mm of the "chicken nest" type (French terminology) consists of the following operations: laying a layer of crushed stone of fraction 14-20; distribution of the binder on the layer of crushed stone 14-20; laying the 2nd layer of crushed stone 10-14; spraying the binder onto the crushed stone layer 10-14; laying of the 3rd layer of crushed stone 6-10; spraying the binder onto the crushed stone layer 6-10; laying of the 4th layer of crushed stone 4-6; spraying the binder onto the crushed stone layer 4-6; laying of the 5th layer of crushed stone 2-4 and compaction.

It is important to ensure the correct dosage of the binder when spraying the emulsion over the rubble. Crushed stone should only be covered with a film of binder, but not buried in it. The total consumption of the binder should not exceed the ratio of binder: crushed stone = 1:10 by weight. The number of layers and the size of crushed stone fractions depends on the depth of the pothole. When repairing shallow potholes up to 10-15 mm deep, the repair is carried out in the following order: laying a layer of crushed stone 4-6; spraying binder on crushed stone 4-6; distribution of crushed stone 2-4 and compaction.

These methods are applicable when repairing black-gravel and black-gravel surfaces on roads with low traffic volumes. The disadvantages of using such methods are that the presence of a layer of variable thickness can cause destruction of the edges of the patch, and appearance patches follow the shape of the pothole.

Patching of asphalt concrete pavements using an asphalt heater... The technology of work is greatly simplified in the case of performing patching with preliminary heating asphalt concrete pavement over the entire area of ​​the map. For these purposes, a special self-propelled machine can be used - an asphalt heater, which allows heating the asphalt concrete pavement to 100-200 ° C. The same machine is used to dry the repaired areas in wet weather.

The heating mode consists of two periods: heating the coating surface to a temperature of 180 ° C and further smoother heating of the coating along the entire width to a temperature of about 80 ° C in the lower part of the heated layer at a constant temperature on the coating surface. The heating mode is regulated by changing the gas flow rate and the height of the burners above the coating from 10 to 20 cm.

After warming up, the asphalt concrete pavement is loosened with a rake to the entire depth of the pothole, a new hot asphalt concrete mixture from a thermos hopper is added to it, mixed with the old mixture, distributed over the entire width of the card with a layer 1.2-1.3 times greater than the depth, taking into account the compaction coefficient and compacted from the edges to the middle of the place being repaired with a manual vibratory roller or a self-propelled roller. The junctions of the old and new coatings are heated using a line of burners that are part of the asphalt heater. The line of burners is a mobile metal frame with infrared burners mounted on it, which are supplied with gas from cylinders according to flexible hose... During the repair work, the coating temperature should be within 130-150 ° C, and by the end of the compaction work - not lower than 100-140 ° C.

The use of an asphalt heater greatly simplifies the patching technology and improves the quality of work.

The use of gas-fired asphalt heaters requires special attention and adherence to safety regulations. No work allowed gas burners at a wind speed of more than 6-8 m / s, when a gust of wind can extinguish the flame on some of the burners, and the gas from them will flow, concentrate in large quantities and may explode.

Asphalt heaters operating on liquid fuel or with electrical sources of infrared radiation.

Repair of asphalt concrete pavements using special patching machines or road repairmen. The most effective and high-quality type of patching is repair carried out using special machines called road repairmen. Road repairmen are used as a means of complex mechanization of road repair work, since they are used not only for patching road surfaces, but also for filling cracks and filling seams.

Technology system patching using a road repairman involves the usual operations. If the repairman is equipped with a heater, the repair technology is greatly facilitated.

Simplified patching methods (injection methods)... In recent years, simplified patching methods using special machines such as "Savalco" (Sweden), "Rusco", "Dura Petcher", "Blow Petcher" and others have become more and more widespread. In Russia, similar machines are produced in the form of special trailed equipment - a sealant of the BTsM-24 and UDN-1 brands. Pothole repair using the injection method is performed using a cationic emulsion. Pothole cleaning for repair is carried out with a jet of compressed air or by suction; priming - an emulsion heated to 60-75 ° C; filling - with crushed stone blackened during the injection process. With this repair method, trimming of the edges can be omitted.

Crushed stone with a fraction of 5-8 (10) mm and an emulsion of the EBK-2 type are used as a repair material. A concentrated emulsion (60-70%) is used on bitumen BND 90/130 or 60/90 with an approximate consumption of 10-11% of the crushed stone mass. The surface of the repaired area is sprinkled with white crushed stone in a layer of one crushed stone. The movement is opened in 10-15 minutes. Works are carried out at an air temperature not lower than + 5 ° С both on dry and wet surfaces.

Injection patching is performed in the following order (Fig.13.12):

Rice. 13.12. Patching by simplified technology:
1 - cleaning of potholes by blowing with compressed air; 2 - priming with bitumen emulsion; 3 - filling with crushed stone, treated with emulsion; 4 - applying a thin layer of untreated rubble

the first stage - the place of the pit or patch is cleaned with a jet of air under pressure to remove pieces of asphalt concrete, water and debris;

the second stage - priming with a bitumen emulsion of the bottom, walls of the pothole and the surface of the adjacent asphalt concrete pavement. The flow of the emulsion is controlled by a control valve on the main nozzle. The emulsion enters the air stream from the spray ring. The temperature of the emulsion should be about 50 ° C;

the third stage is filling the pothole with repair material. The crushed stone is introduced into the air stream using a screw conveyor, then enters the main mouthpiece, where it is covered with an emulsion from the spray ring, and from it the processed material is thrown out at high speed into the pothole, distributed in thin layers. Compaction occurs due to the forces arising from the high speeds of the ejected material. The suspended flexible hose is controlled remotely by the operator;

the fourth stage is the application of a protective layer of dry, untreated rubble to the patch area. In this case, the valve on the main nozzle, which controls the flow of the emulsion, is turned off.

It should be noted that the exclusion of preliminary cutting of the pothole edges leads to the fact that in the near-edge zone of the pothole there remains old asphalt concrete with a broken structure, which, as a rule, has a reduced adhesion to the underlying layer. The service life of such a patch will be shorter than with traditional technology... In addition, the patches have irregular shapes, which deteriorates the appearance of the coating.

Patching using cast asphalt mixes. Distinctive feature cast asphalt concrete mixtures is that they are laid in a fluid state, as a result of which they easily fill potholes and do not require compaction. Fine-grained or sandy cast asphalt can be used for repairs at low air temperatures (down to -10 ° C). Most often, for repair work, a sandy cast asphalt concrete mixture is used, consisting of natural or artificial quartz sand in the amount of 85% by weight, mineral powder - 15% and bitumen - 10-12%. For the preparation of cast asphalt, viscous refractory bitumen with a penetration of 40/60 is used. The mixture is prepared in mixing plants with forced-action mixers at a mixing temperature of 220-240 ° C. The mixture is transported to the place of laying in special mobile boilers of the "Kocher" type or in thermos bunkers.

The delivered mixture at a temperature of 200-220 ° C is poured into a prepared pothole and easily leveled with wooden floats. An easily mobile mixture fills all irregularities, due to the high temperature it heats up the bottom and walls of the pothole, as a result of which a strong connection of the repair material from the side of the coating is achieved.

Since a fine-grained or sandy cast mixture creates a slippery surface of the pavement, measures must be taken to improve its adhesion properties. For these purposes, immediately after the distribution of the mixture, black crushed stone 3-5 or 5-8 is scattered over it with a consumption of 5-8 kg / m 2 so that the crushed stone is evenly distributed in a layer of one crushed stone. After the mixture has cooled down to 80-100 ° C, crushed stone is rolled with a hand roller weighing 30-50 kg. When the mixture cools down to the ambient temperature, the excess crushed stone, which has not been sunk into the mixture, is swept away and the movement is opened.

Poured asphalt concrete mixtures during patching can be laid manually or with a special asphalt paver with a heating system. The advantage of this technology is that operations on priming the repair card and compaction of the mixture are excluded, as well as in high strength the repair layer and the reliability of the mating seams of new and old materials. The disadvantages are the need to use special mixers, heated mobile rollers and mixers or thermoses-bunkers, viscous refractory bitumen, as well as increased requirements for safety and labor protection when working with a mixture that has a very high temperature.

In addition, poured asphalt during operation has a significantly higher strength and lower deformability compared to conventional asphalt concrete. Therefore, when a conventional asphalt pavement is repaired with cast asphalt, after a few years, this pavement begins to deteriorate around the cast asphalt patch, which is explained by the difference in physical and mechanical properties old and new material. Cast asphalt is most often used for patching city roads and streets.

One of the ways to simplify the work technology and increase the construction season is the use of cold asphalt concrete mixtures based on polymer bitumen binder (PBB) as a repair material. These mixtures are prepared using a complex binder, which consists of bitumen with a viscosity of 60/90 in an amount of about 80% by weight of the binder, a polymeric modifying additive in an amount of 5-6% and a solvent, for example diesel fuel, in the amount of 15% by weight of the binder. The binder is prepared by mixing the components at a temperature of 100-110 ° C.

Asphalt-concrete mixture on PBB is prepared in mixers with forced mixing at a temperature of 50-60 ° C. The mixture consists of fine crushed stone of fractions 3-10 in the amount of 85% by weight of the mineral material, screening out 0-3 in the amount of 15% and binder in the amount of 3-4% of the total weight of the mineral material. Then the mixture is stored in an open pile, where it can be stored for up to 2 years, or loaded into bags or barrels, in which it can be stored for several years, retaining its technological properties, including mobility, plasticity, lack of caking and high adhesion characteristics.

The repair technology using this mixture is extremely simple: the mixture from the car body or from the bunker of the road repairman, manually or with the help of a hose, is fed into the pothole and leveled, after which the traffic is opened, under the influence of which the road layer is formed. The whole process of repairing a pothole takes 2-4 minutes, since the operations of marking the map, cutting and cleaning the pothole, as well as compaction with rollers or vibratory rollers are excluded. The adhesive properties of the mixture are preserved even when it is placed in potholes filled with water. Repair work can be carried out at a negative air temperature, the limit of which needs to be specified. All this makes the indicated patching method very attractive for practical purposes.

However, it also has a number of significant disadvantages. First of all, there is a possibility of rapid destruction of the repaired pothole due to the fact that its weakened edges are not removed. When working in damp weather or in the presence of water in a pothole, part of the moisture can get into microcracks and pores of the old coating and freeze when the coating temperature drops below 0. In this case, the process of destruction of the interface of the new and old materials can be initiated. The second disadvantage of this repair method is that after the repair, an irregular external shape of the pothole remains, which impairs the aesthetic perception of the road.

The presence of a large number of patching methods makes it possible to choose the optimal one based on specific conditions, taking into account the condition of the road, the number and size of coating defects, the availability of materials and equipment, the timing of the repair and other circumstances.

In any case, it is necessary to strive for the elimination of dimples at an early stage of its development. After patching, in many cases it is advisable to arrange a surface treatment or lay protective layer, which will give a uniform appearance to the coating and prevent its destruction.

The most common type of road surface is asphalt. It is convenient not only because of the not very complicated manufacturing and laying technology. The asphalt pavement can be easily repaired and renewed.

Why does the asphalt deteriorate

The main factors that lead to damage to the road surface:

• violation of laying technology;
• seasonal temperature changes and aggressive environment;
• soil transformation;
• exceeding the design loads.

Paving technology violations include working in wet weather or using asphalt at temperatures environment, which does not correspond to technological standards for this type of material. Moisture trapped during installation, even in very small quantities, will expand during winter when it freezes and break the integrity of the road. In addition, it is difficult to achieve complete adhesion between the asphalt and the substrate in wet weather.

External factors also greatly affect the life of the road surface. The high temperatures in summer softens the asphalt and a normal laden car will dent it. If a heavy crawler vehicle passes, then you can start repairing the asphalt immediately.

In winter, it is not only frozen water that cracks the roadway. Fighting ice in the form of sprinkling with salt or abrasive substances also brings significant harm to the integrity of roads, pits and depressions appear.

Often, raised groundwater and displacement of the lower soil layers lead to the appearance of cracks. In this case, small local repair cannot be dispensed with and a full-scale replacement of the coating is required.

Types of repair work

In accordance with the damage, the roadway may require the following types of repairs:

• capital;
• current.

Overhaul can also be of two types:

1. local, in which the upper damaged layer is removed, the resulting space is impregnated with solutions and poured with bitumen, then just a new layer of asphalt is laid;
2. full-scale, providing for the removal of the entire coating and replacement with a new one.

There are several types maintenance asphalt:

• dimple;
• elimination of cracks;
• application of "wear mats".

Before carrying out repair work, it is necessary to determine the extent of the damage: if 1-2 cracks are found, they can be repaired with bitumen or a bitumen-rubber mixture, and if there are group nets that intersect at different angles, it is better to patch the asphalt. If layer shifts are visible or the entire canvas looks like a continuous mesh of gaps, then a major overhaul is carried out and the entire coating is completely replaced.

We repair minor damage - cracks

Repairing cracks with bitumen is the easiest way to repair road damage. The main stages of repair work:

• cleaning cracks from pollution, dust, debris;
• blow out and dry the place of the fault;
• warm up the entire crack so that the asphalt heats up, but does not start flowing;
• heating bitumen and pouring it into the gap;
• leveling the surface.

Master's advice! Hot and cold sealants can be used instead of bitumen.

Another common way to seal cracks is with bitumen rubber tape. The tape is laid in a fault, which has been previously cleaned and smeared with bitumen. To obtain an airtight coating, a mixture of bitumen and rubber is carefully rammed into the damage.

Using the patching method of repair

The most commonly used method of repairing damage is patching the asphalt. There are several methods for carrying out such repairs:

1. using hot asphalt;
2. cold way;
3. cast coating;
4. infrared repair;
5. cold jet injection technology.

In order to choose a specific method correctly, it is necessary to provide for its good result for a specific type of damage, and this depends on the following factors:

• coincidence of the material used with the main coating in terms of density, evenness, roughness;
• availability of equipment providing the technology of the chosen method;
• weather;
• economic profitability, depending on the possibility of quick restoration of traffic and the cost of the repair work itself.

The need to carry out repair work not only in the summer-spring period, but all year round involves the use of most often cold mixtures. In addition, they can be stacked even when sub-zero temperature, they are also stored for a long time, while hot asphalt presupposes laying immediately after production.

Note! There are several types of cold mixes on the construction market: emulsion-mineral, organomineral, emulsion. They differ in terms of storage time and ambient temperature, which allows their use.

The technology of patching asphalt using a cold mix has several stages:

• cleaning the roadway from dust, dirt, snow;
• marking the location of faults, both single and grid;
• cutting out the contours of potholes, pits;
• cleaning cut holes from dust and debris;
• warming up the entire surface of the pothole, including the walls;
• impregnation of the walls, bottom of the pit with a binder on an organic basis;
• styling, tamping of the coldest filler.

From this chain of work, you can exclude the cutting of a part of the coating if the potholes and cracks themselves are not very large. But then more attention should be paid to the compaction of the cold mixture.

New trend in road renovation

The most economical and environmentally friendly is infrared asphalt repair. The savings are achieved by using the minimum amount of new asphalt. Environmental friendliness is that there is no high level noise and dust that accompany the removal of the old coating, there is no need to block traffic.

The essence of the infrared method consists in heating the damaged coating from the inside and sealing cracks and damages with the same composition. The result is a repaired seamless roadway, which significantly increases its service life. Infrared repair of asphalt is carried out in the following sequence:

• the canvas is cleared of dust, moisture, dirt;
• using an installation that carries out infrared heating, the damaged area is heated;
• the heated and softened material is loosened so as to remove joints, irregularities;
• if necessary, a little new mixture is added to completely fill the hole or pothole;
• the damaged area is compacted and leveled.

The result is an updated site, with minimal cost for repairs and no visible signs of damage.