What is the current repair of roads. Road Repair Technology

Road Repair Technology

TO category:

Operation of special vehicles

Road Repair Technology

During the operation of roads, their coatings are exposed to moving vehicles, various climatic factors, etc., which causes deformation, destruction and wear of the coating. Malfunctions of the road surface, leading to a decrease in the performance of the road, are eliminated by repair work.

Distinguish between current, medium and major road repairs. Maintenance is carried out mainly in the warm season, at an air temperature of at least +5 ° C. However, if the malfunctions that occur can lead to great damage, they repair the road regardless of the air temperature.

The average repair is carried out in accordance with the established turnaround time, that is, 1 time for several years, in order to strengthen the pavement by restoring the wear layer. Medium repair work is significant in volume and can cover up to 40% of the total coverage area. Overhaul is carried out periodically in the established turnaround time in order to fully restore or increase the strength of the road surface, or, if necessary, change the geometric parameters of the road surface. Distinctive feature overhaul - the scope of work covers the entire width of the road over a long distance

With the current repair of asphalt concrete pavements, cracks, potholes, subsidence, waves and sagging on the pavement, as well as damage to the side stone, are eliminated. v Crack sealing is one of the most common malfunctions of asphalt concrete pavement. Open cracks contribute to the accelerated destruction of the coating, therefore ^ timely liquidation of them ensures the preservation of asphalt concrete in proper operating condition. When repairing cracks fill sealed materials. This operation is preceded by a thorough cleaning of cracks (metal hooks and compressed air) from contaminants and dust to ensure proper adhesion of the filling material with asphalt concrete. If the width of the cracks is less than 5 mm, liquefied bitumen or special rubber-bitumen mastic is used to fill them, if more than 5 mm - liquefied bitumen or astringent mastics. After filling the cracks with liquefied bitumen, they are sprinkled with mineral materials. If the road surface has a grid of small cracks, it is recommended not to fill them separately, but to repair the entire surface.

Cracks are closed in dry weather, at temperatures not lower than 5 ° C with a special machine. It is most advisable to carry out work in spring or autumn.

Potholes and subsidence dramatically reduce the performance of coatings. When repairing damage to mash-up coatings, pits are first prepared and potholes are thoroughly cleaned of contaminants and their contours are marked with straight lines perpendicular and parallel to the axis of the road. If the potholes are located at a short distance from each other, then they are combined into one common card. The distance from the damage to the border of the repaired area should be within 3-5 cm. Then, the repaired part is cut down along the intended contour to the depth of destruction, but not less than 3-4 cm.

When repairing a two- or multi-layer coating, when the adhesion of the upper layer is unsatisfactory, they cut it down to the full depth. They also act with the second and subsequent layers, if the damage extends to them. The walls of the cut contour must be strictly sheer. Then, the place to be repaired is thoroughly cleaned of cut asphalt concrete and contaminants, and the internal surfaces are lubricated with liquid or viscous (liquefied) bitumen.

A hot asphalt mixture with a temperature of 150-180 ° C is placed in a place prepared in this way. Depending on the depth of felling, the mixture is laid in one (with a depth of less than 5 cm) or in two layers, and it should be slightly higher than the pavement, taking into account the fact that hot mixtures are compacted at a compaction ratio of 1.25-1.35. In cards up to 3-5 m2 in area, the mixture is compacted with a hand tool, pneumatic or electric rammers. Motor skating rinks are used in the repair of large-area cards. The interface between the newly laid and old asphalt concrete is carefully smoothed so that the surface of the pavement is smooth, without sag and open joints.

The damage is mechanized, using appropriate machines. To clean up the contaminants (when preparing the coating for marking), sweepers or watering-washing machines are used. The main cycle of work is performed using machines for the routine repair of roads and sidewalks. When repairing damage to coatings over large areas (map area more than 25 m2), an asphalt spreader is used for layout and leveling asphalt mix.

In addition to this repair method, a repair method based on heating the surface of a repaired place is becoming more widespread. Two types of asphalt and heat heaters are used for heating: machines that affect asphalt concrete with an open flame, and flameless type heaters. The operation of asphalt heaters with an open flame is imperfect, as this results in the burning of bitumen in asphalt concrete and it loses its ductility. The work of heaters of this type is accompanied by noise, soot, smoke, which does not meet the working conditions on city roads and the requirements of environmental protection. Better asphalt heaters equipped with infrared burners. In this case, asphalt concrete retains its physical and mechanical properties during heating and acquires the plasticity necessary for repair. The place to be repaired (after thorough cleaning of contaminants) is heated using infrared burners to a temperature of 130-150 ° C. the heated asphalt concrete is loosened up, a certain amount of the asphalt concrete mixture is added to it and compacted with a motor roller or using a hand tool. Such asphalt heaters are equipped with a portable ruler with infrared burners, a hopper for transporting asphalt mix. A portable ruler with infrared burners is used to repair elongated potholes, wide cracks, as well as damaged areas along the side stone or walls of buildings.

In the absence of coating breaks, small waves and sag are eliminated by rolling the deformed coating sections. To ensure the proper quality of work, the area with waves and influxes must be given plasticity by heating it with an asphalt heater using infrared burners. Before heating, the repaired area is thoroughly cleaned of impurities, and after heating, they are rolled off with a motor skating rink until they eliminate waves and influxes. At high air temperatures, causing softening of the pavement, waves and sag are eliminated without pre-heating the deformed area using an asphalt heater.

Pavement areas of a large area, with significant height and height of influxes and waves formed as a result of breaking the adhesion of the top layer of asphalt concrete to the base, are repaired by completely replacing the coating. Why the asphalt heater is heated, and then the top layer is removed. After that, fresh shear-resistant asphalt mixture is laid by pavers and rolled it.

To correct landings and minor damage to the side stone using an electric or pneumatic tool, open the coating along the sagging side stone. Then the sagging stones are lifted using the ED-3M attachments to the Belarus excavator, the base under the stone is leveled and corrected using cement mortar or concrete mix. The side stone is thoroughly washed and manually set in the design position, filling the joints with cement mortar. After that, manually (or using a machine for routine repair), the damaged pavement is repaired.

Minor damage on the surface of the side stone is corrected as follows. The surface is thoroughly cleaned of dirt and dust with a mechanical brush and washed with a 30% hydrochloric acid solution. Colloidal cement glue is applied to the cleaned surface with a brush or spray and immediately damage is manually repaired with a mixture of cement-sand concrete. The mixture should protrude above the damaged surface at 20-25% of the fracture depth. Then it is compacted with a surface vibrator to a general level.

During the current repair of cement concrete pavement fill and close damaged joints, eliminate peeling, cracks, potholes and sinks.

Before repairing the seams, the repaired places are pre-cleaned of contaminants and oil stains at small volumes manually using hard, metal brushes, and with significant ones, with electric brushes. Oil stains are removed by treating them with an aqueous solution of hydrochloric acid or using sandblasting machines. The cleaned places are washed with water (watering and washing machine) and purged with compressed air, removing the water remaining in the repaired places. The adhesion strength of damaged cement concrete surfaces to repair materials and, consequently, the quality of repair, i.e., the quality of sealing damaged areas with bitumen rubber and sealing pastes, largely depend on the quality of the preparatory work. Mastic or paste in damaged places is served by special machines, and for small volumes of work - by manual fillers of cracks. With a deep destruction of the edges of the seam in excess of 4-5 cm, the damaged area is cut down, cleaned and sealed with concrete.

In a ruined place, a groove is cut to a depth of at least 7 cm, using a seam cutter or a concrete saw for this, after which the site prepared for repair is manually primed with cement mortar. Filling the seams and repaired places with mastic or paste, they are sprinkled with mineral powder or sealed with roll paper.

To eliminate peeling, the repaired surface of the cement-concrete coating is thoroughly cleaned of contaminants using electric brushes or a sandblasting apparatus. If the repaired surface is heavily contaminated, has oil spots, then it is cleaned with an aqueous solution of hydrochloric acid, and then washed with water (a watering and washing machine) and purged with compressed air from the compressor unit, removing the water remaining on the repaired surface. In the absence of compressed air, surface repair begins only after it has completely dried. With a depth of destruction of up to 1 cm, peeling is eliminated using a manual grout or a machine for pouring cracks that distribute special mastic based on epoxy glue over the damaged surface. With a destruction depth of more than 1 cm (but not more than 3 cm), the damaged surface is covered with an epoxy-mineral mixture.

The mixture is sprinkled with sand using a sand spreader and compacted with rollers.

It is recommended to close cracks immediately after their formation, since they entail further destruction of the coatings. Before sealing, the crack must be cleaned of stone fines, dirt and dust (hooks and steel brushes) to ensure good adhesion of the repair material to cement concrete. After cleaning, the crack is closed with liquid or liquefied bitumen, mastic, bitumen emulsion or concrete mix. Depending on the scope of work and the size of the cracks in depth and latitude, they are sealed with an airbrush or crack fill.

Covering potholes and sinks up to 5 cm deep on a cement-concrete pavement, their lines are marked with straight lines along which cement concrete is cut using a seam cutter or pneumatic tool. Then, using an electric or pneumatic tool, the concrete is cracked. The place to be repaired is thoroughly cleaned of concrete residues and impurities, using an electric brush or compressed air from the compressor, and washed. Then, the inner surfaces are primed with epoxy glue and sand-concrete mixture is laid in the felling. Small cuttings are compacted by hand, large ones - by surface vibrators.

Potholes and sinks with a depth of more than 5 cm are eliminated after cutting and cleaning the prepared area in a different way. The edges of the felling and its bottom are moistened for several hours with water. A thin layer of cement-sand mortar is applied to the wetted surface. Then sand-concrete or cement-concrete mixture is put into the felling and compacted by hand (by rammers) or surface vibrators.

The average repair of asphalt concrete pavements includes the restoration of the wear layer, the elimination of subsidence and breaks, as well as the replacement of the side stone.

Instead of a worn layer, a thin layer is arranged asphalt concrete pavement, which also serves to level the surface and restore the solidity of the pavement. If there are cracks, potholes or subsidence on the coating, they must be carefully repaired and repaired. Before laying the wear layer, the coating is cleaned of contaminants by sweeping machines or irrigation and washing machines, and then using the auto-distributor, the entire area is lubricated with liquefied bitumen or emulsion. After the solvent in the liquefied bitumen or emulsion evaporates, with the help of an asphalt paver, the asphalt concrete mixture is usually laid in warm, dry weather, at an ambient temperature of at least 15-20 ° C. To ensure the surface roughness of the wear layer, asphalt concrete mixtures with a high content of crushed stone are used. The laid mixture is compacted with rollers.

Drawdowns and breaks with large cards with an average repair are eliminated in the same way as with the current one. The difference lies only in the volume of work, which with an average repair is much larger. In this case, more rational methods of work are used, in particular, asphalt heaters with infrared burners are used, which allow eliminating low-productivity operations for cutting down damaged asphalt concrete.

The failed side stone is replaced with a compressor, which provides cutting and destruction of the seams, as well as the destruction of the road surface adjacent to the stone. The rest of the work (stone excavation and replacement) is done manually or by universal means. If several on-board stones are to be replaced, the first of them is prepared for excavation using a compressor, and the rest is prepared using an excavator with special ED-3M attachments (excavation of a replaceable stone, dumping and loading it into vehicles).

Using the same equipment, the side stones are unloaded and fed to the installation site. After excavation of the replaced bead stone, the soil is leveled and the trough is corrected. The stone after installation manually or using ED-ZM equipment is carefully aligned in height and then the stone adjacent to it is placed. The seams between the stones are filled with cement mortar, and the sinuses with cement-concrete mixture. The junction of the side stones to the coatings is covered with asphalt manually or with a machine for current repair.

During the average repair of cement concrete pavements, roads fix subsidence and worn-out areas with an area of \u200b\u200bmore than 200 m2, replace individual defective slabs, and with continuous peeling, arrange a protective layer.

To eliminate subsidence, raise the concrete slab to a height corresponding to the subsidence depth using jacks or compressed air from the compressor unit. To install the jacks, holes are drilled in the plate in such a way that there is one jack per 3.5 m2 of the plate. In addition, with the help of a drill with a drill or an electric drilling machine, additional holes of smaller diameter are drilled in the plate to pump filling material through them. The plate is raised so that it is on the same level (flush) with the surrounding plates. Then, using a mortar pump or shotcrete apparatus, filling material is pumped through additional holes - a lean cement mortar or soil-silicate mixtures with the addition of cement.

After filling the voids, the jacks are removed, the holes are filled with concrete mixture and the joints are immediately repaired with mastic manually or with the help of a joint filler.

To lift the plate with compressed air, holes of large diameter are also drilled in it from the calculation - one hole per 3-3.5 m2. To lift the plate and inject the filling material into it, all openings, except for one, are closed with plugs. Filling material is pumped through an open hole, then they move to another hole until the plate is flush with the adjacent plates. The material is injected until it starts to flow out through the seams.

When repairing breaks, worn places on a pavement with an area of \u200b\u200bmore than 200 m2, marking, cutting down with a pneumatic tool and thorough cleaning of the repaired places with an electric brush or manually. Then check the quality of the base and, if necessary, remove the underlying layer to a depth of at least 20 cm and replace it with a new one. After chopping and cleaning, the walls of the places to be repaired are greased with cement-sand mortar, and then the concrete mixture is laid and compacted in them.

If it is necessary to replace individual slabs in a cement concrete pavement, then after removing the replaceable slab using a truck crane, check the quality of the base and correct it if necessary. Then, using a crane, a new stove is brought to the place of laying. When lowering, this plate should come in contact with the prepared base at the same time with its entire surface. Laying the slab should occur without distortions while maintaining the longitudinal and transverse seams of the pavement. Then the plate with the help of a vibrator is deposited on the design site and the joints are closed.

The cover layer during continuous peeling is arranged after all defects of the road surface have been eliminated - potholes, cracks, damage to joints, etc. These works must be completed in advance 2-3 weeks before the protective layer is applied. The coating thus prepared with the help of a sweeping machine is thoroughly cleaned of impurities and liquid bitumen heated to a temperature of 150 ° C is poured onto the cleaned surface; liquid, and then viscous bitumen is treated using an asphalt distributor. Then, the protective layer is compacted with rollers, and a day after this operation, the pavement is sprinkled with granite screenings with a sand spreader (with fractions of 5-10 mm). With continuous peeling with a depth of less than 3 cm, the coating is repaired using a cement-sand mixture, for which it is first thoroughly cleaned with a metal brush from dirt and dust, then it is washed (with a watering and washing machine), treated with colloidal glue, and a cement-sand mixture is distributed using a paver .

Overhaul of asphalt concrete pavement is its restoration with removal or using old asphalt concrete as a base.

The road surface is restored with the removal of old asphalt concrete, usually using special machines of shock-milling type, providing a layer removal of up to 10 cm thick. However, the productivity of such machines is insignificant (up to 200 m2 / h), therefore, asphalt heaters with burners are increasingly used for these works. infrared radiation. At the same time, asphalt heaters equipped with milling devices for removing heated to 120-140 ° C and a softened layer to a depth of 3-10 cm showed themselves from the best side. In the absence of a milling device, heated asphalt concrete is removed using a grader. The width, depth of heating and milling of the top layer depends on the area of \u200b\u200bdamage, the presence of wells on the road surface, etc. After removing the old asphalt concrete layer, the resulting base is treated with liquid bitumen or bitumen emulsion with a tar spray for better adhesion, and then a new paver is laid asphalt layer. If the road surface is restored to the full width of the carriageway, the mixture is laid with two pavers moving with a ledge along adjacent strips at a distance of 10-15 m from each other. The laid asphalt mix is \u200b\u200bcompacted with rollers - first light, then heavy. During the compaction process, after the first passes of the rollers, the evenness of the coating is checked in the longitudinal and transverse directions.

Restoring the pavement without removing the old asphalt concrete is applicable if it is possible to increase the height of the asphalt layer without disturbing the interface with the road surface of adjacent streets and driveways, building entrances, as well as without disrupting the operation of storm sewers. After thoroughly cleaning the pavement from contamination with sweeping and watering machines, it is treated with liquid bitumen or a bitumen emulsion using an asphalt distributor. Then the asphalt mixture is laid, using, depending on the amount of work, an asphalt paver or asphalt paver, and compacted with rollers.

During a major repair of cement concrete pavement, areas with sagging slabs are repaired, a large number of destroyed slabs are replaced with new ones, the foundation is restored, peeling is eliminated over large areas, etc. The technology for performing these works is the same as for current and average repairs, and the difference is only in the scope of work.

In connection with the large volumes of work at overhaul it is necessary to widely use machines and mechanisms, in particular, for those operations that are still performed manually during current and secondary repairs.

TO Category: - Operation of special vehicles

Construction and repair of roads - An extremely urgent topic for our state, since the quality of asphalting in most regions leaves much to be desired. There are many ways to bring the road surface in proper condition. We offer for your consideration the most popular types of them.

There are two ways to implement the regeneration of the pavement: hot and cold. At hot regeneration the whole composition roadbed heated with special equipment. Thus, a viscous condition of the road surface is achieved. In this state, it is easily deformed, which greatly facilitates the process of its restoration. Until recently, restoration of the roadway using the hot regeneration method could be carried out only on small sections of the road surface, but now, due to the appearance of mobile aggregates, it has become possible to regenerate asphalt concrete pavement along its entire width.

Foreign experts in the field of pavement restoration distinguish the following types of hot regeneration:

thermal restoration of the road surface with the addition of crushed stone;
thermal restoration of the canvas to its original form;
thermal recovery with the gradual addition of an asphalt mixture and subsequent mixing;
thermal restoration by adding asphalt concrete pavement;
thermal restoration of the lower layer of the canvas with the subsequent application of a new upper layer.

What about cold regeneration , then it can be made both directly at the place of repair, or in a specialized installation. The meaning of this method is to introduce new components into the asphalt concrete pavement that strengthen the structure of the composition and thereby improve the quality of the roadway as a whole. It is worth noting that, according to most foreign experts, road repair using the cold regeneration method asphalt pavement directly at the repair site is one of the most promising types of roadway regeneration.

Surface treatment of the roadway

This method of restoration is subject to absolutely any type of roadbed. Surface treatment is divided into: single, double and triple.

The essence of surface treatment consists in the uniform distribution of the organic binder, which includes mineral additives, over the entire surface of the roadway. As the binder itself, tar, bitumen emulsion, polymer bitumen or materials made on the basis of epoxy resin are used. The choice of binder is largely determined weather conditionsat which processing will be carried out, and, of course, directly from the type of pavement itself. Unfortunately, bitumens of predominantly low quality are produced in Russia, which leads to a fairly rapid breaking of the pavement after the repair of roads made by the surface treatment method. The situation can be corrected only by the use of high-quality imported bitumen containing polymer additives.

This type of repair of the roadway is most justified in those cases when signs of rutting begin to appear on the surface. A substance with a bitumen content of more than 60% acts as a binder in a concrete emulsion. Grain mineral material is selected based on the requirements for the thickness of the applied layer. If the track does not exceed 30 millimeters in depth, then the size of the grains used should be about 8 millimeters. If the track has a large depth, it is advisable to use grains with a diameter of 11 millimeters and above.

Concrete emulsion is sprayed on the surface of the roadway by special road equipment equipped with nozzles. At the back of each such machine is a rubber band or screed. Thus, road equipment is able to independently complete the installation process.

Work on the application of concrete emulsions should be carried out at an ambient temperature of at least 5 ° C, otherwise rapid wear of the road surface is possible. If night frosts are expected in the region where roads are being repaired, then you should not start work. It should also be borne in mind that concrete emulsions must be applied exclusively to a clean surface.

The advantage of this method is that already 30 minutes after the end of work, the road can be opened for the movement of cars. It is also worth noting the low consumption of concrete emulsion: 25-30 kg / m².

Membrane washing

This repair method is relatively new. It was developed in the Netherlands and can significantly improve the quality and wear resistance of the roadway. The essence of the method is to wash onto a damaged road surface a special liquid consisting of bitumen and granular fine material.

If there is a need to repair only one pothole or crack, resort to the simplest method of washing the membranes. A certain amount of bitumen emulsion is sprayed onto the surface of the roadway, after which sand is added to it, then the resulting mixture is swept into a pothole. In order to prevent the resulting mass from sticking to the wheels of a passing vehicle, the patched pothole is abundantly sprinkled with gravel or sand.

If the asphalting of the road was initially not carried out at the proper levelAs a result of which the coating needs a full-scale repair, special mobile units should be used. Such installations are ordinary continuous mixers and can be mounted on any road equipment. In the course of work, such installations mix emulsion, crushed stone, sand and necessary additives, after which the resulting solution is sprayed directly onto the road surface. Tamping the canvas after this is not required, since the resulting composition of the membrane type is absorbed into the asphalt extremely quickly.

Friends! Recently, I often come across the fact that many people confuse different types of repair work on roads, ask when and by what technologies it is possible to carry out construction and technical work, in what weather, etc. etc.
Since recently I had to delve deeper into the study of this issue, I believe that I can give some clarifications to others. This post opens a series of publications to explain all these subtleties. To begin, consider the main types of repair of the roadway.

PATIENT REPAIR

In the modern world, patching of the pavement is considered advisable when the amount of damage on the road does not exceed 15%. In opposite cases, repair is required with the complete replacement of certain layers of the road surface. Patching is the fastest, cheapest and easiest way to year-round restoration of minor shallow damage, which must be repaired in a fairly short time, established by the "Requirements for the operational state, permissible under safety conditions traffic (GOST R 50597-93) ”- from 5 to 10 days, depending on the category of road. Patch repair refers to the current repair and includes: the elimination of pits, potholes, chips, cracks.
The most famous, but at the same time labor-intensive method of patching is the so-called. hot technology. With this method, an almost complete production cycle is involved, as when laying a new asphalt concrete layer. The sometimes poor quality and short service life of defective places patched with a hot mixture are associated primarily with poor preparation of such places for repair, delivery hot mix in vehicles unsuitable for heat preservation (often there is excessive cooling of the mixture at the time of its use) ‚poor quality of mixture compaction and other elementary violations of the rules‚ requirements and repair techniques (laying the mixture on a wet surface ‚in water‚ on snow ‚without primers, etc.). There is a "cold" technology. In this case, repairs can be carried out not only on the wet surface of the coating, but also at small negative air temperatures (up to -5 ... -10С), although from the point of view of quality of work, positive temperatures are preferable. The strength and water resistance of cold asphalt concrete, prepared on liquid or liquefied bitumen, is 2-3 times lower than hot. An advanced patching method is jet injection. Its main advantage is that the whole procedure is performed using one single installation without preparatory cutting and milling of the surface. The embossment of the pothole itself is carried out by filling it with small gravel ‚pre-treated with bitumen emulsion in the mixing chamber of the machine. Due to the involvement and supply of crushed stone by an air stream, its laying in a pothole occurs at a high speed, which ensures its good packing (compaction), virtually eliminating the need for additional use of vibrating plates and vibratory rollers. Puncture jetting can be used almost all year round.
The average cost of patching in Ulyanovsk is from 400 to 900 rubles per 1 square meter.

CARD REPAIR

Card repair means the complete replacement of the top layer of the road surface with a width of up to 6-8 cm in a certain section of the road (wear layer).
This type of repair must comply with all applicable regulatory and technical requirements, including SNiP 3.06.03-85 "Roads", Guidelines for the repair and maintenance of public roads (Letter of Rosavtodor dated March 17, 2004 No. OS-28/1270-is). The normative “card” repair refers to the current one, since a major change is made to a more significant change in the characteristics of the road. When repairing a worn coating by milling and laying a new layer, there is no need to repair the damage, and it becomes possible to partially correct the transverse slopes.
Replacing Top Wear pavement without proper preparation of the underlying layer - the leveling one - leads to deeper and difficult to eliminate consequences in the form of destruction of the leveling layer and damage or excessive moisture saturation of the base. The device of new layers of pavement is carried out with additional operations for continuous picking, profiling and compaction of the existing coating, cleaning the coating from dust and dirt, priming and drying.
The specified method in Ulyanovsk in 2013, repairs were carried out on the streets of Karl Liebknecht, Inzenskaya, Kamyshinskaya, Ryabikova, Federation, September 12, Leo Tolstoy and others.
The cost of card repair depends on the width of the roadway, the amount of materials used. For example, on the street Karl Liebknecht replacing the top layer by 1 meter cost 5,200 rubles, on Inzenskaya street - about 8,500 rubles.

CAPITAL REPAIR

Overhaul of roads includes a full cycle of work to restore the strength characteristics and geometric dimensions of the road (in accordance with the requirements of the project) while replacing worn, lost strength and required properties of structural layers of pavement and artificial structures to design standards. So, in Ulyanovsk in 2013, overhaul was carried out on the streets of Oktyabrskaya, Pushkareva, Leninsky Komsomol Avenue, and also which year is carried out on the section of the highway from Dimitrovgrad highway to Mirny settlement.
Guidelines for the repair and maintenance of public roads (Letter of Rosavtodor dated 03/17/2004 No. OS-28/1270-is) establish specific requirements for the overhaul of roads, and SNiP 3.06.03-85 "Roads" contains normative indicators that a repaired road must meet (this Construction Norms and Regulations establishes methods for the construction of new and reconstruction of old roads, while the regulatory requirements are used as indicators in the production of repair work).
With the overhaul of roads, the correct and conscientious acceptance by customers is of great importance. Necessarily produced inspection of works in kind, control measurements, verification of the results of production and laboratory tests of building materials and control samples. Acceptance is made according to all parameters of the road:
- the density of the layers of pavement;
- the evenness of the layers of the bases and coatings by determining the algebraic differences of elevations;
- grip of the car tire with a coating (for the upper layers) or roughness of the coating;
- the strength of the material and the thickness of the coating in three cores per 1000 m 2 when identifying inconsistencies of these parameters with the required values \u200b\u200bby other control methods.
On the roads I and category II, as well as when applied to highways improved capital types of pavements using new building materials or atypical structures of pavement, acceptance control should usually be carried out specialized organizations.

The photo on the left shows how the core fell apart at the time of its excavation. The reason is the loss of adhesion between the layers of pavement due to the laying of asphalt concrete in the snow (