Current repair of asphalt concrete pavement. Asphalt patching

Asphalting roads and other communications has always been very important in our lives. But sooner or later you can observe such a phenomenon as the wear of the roadway. Cracks, chips, potholes, and even pits may appear in the road surface, that is, in some places of various sections of the road, asphalt repair is required.

The technology for the production of pavement repair was developed and mastered a long time ago, but even today you can encounter cases of unfair repair work. However, this no longer applies to the technology itself, it simply becomes necessary to require the heads of repair teams to comply with all established standards.

Yes, the destruction of asphalt is a fairly common phenomenon even in highly developed countries, and not only here.

This happens despite the characteristics of strength, water resistance, frost resistance and similar parameters.

There comes a time when you still need to resort to asphalt repair. Asphalt - the material, in principle, is not very durable, moreover, it is affected by many different factors, which will be discussed below.

Asphalt Features

Asphalt is also called asphalt concrete.. In principle, asphalt concrete is similar to concrete - it also consists of sand, crushed stone and binders. But unlike concrete, where the binder component is cement, in asphalt this component is bitumen created by processing petroleum products.

Asphalt is a very durable material, but, however, over time, various kinds of cracks, pits, and potholes appear in it.

Asphalt wear occurs due to a number of factors, and not only because of the relatively high pressure of vehicles on the road surface:

• Weather and climatic conditions, of which frost is the most destructive;
• In addition, ultraviolet, which eventually destroys bitumen, and even oil from cars adversely affects the road surface.

In general, these phenomena need to be fought. eliminates problems with the road surface, although a set of preventive measures must be applied.

Asphalt pavements are resurfaced every few years, and the various cracks in the pothole are treated with a special water-resistant sealant.

These sealants are needed in order to fight against various chemical attacks. And if the asphalt is already starting to crumble, then it is necessary to change the coating in this place entirely. If the cracks are more than 20 mm, then a special repair compound with the addition of sand can be used to seal them, this is necessary to create a more rigid content. Allow all components to dry after application.

Both cracks and pits and potholes have different sizes, therefore, to eliminate them, it is necessary to use a variety of technologies.

If various types of sealants can be used in small cracks, then the so-called “cold asphalt” is used to eliminate holes and potholes with a diameter larger than ordinary damage. This material has its own article numbers and data, which indicate rather high properties of cold asphalt. is made directly from the container by pouring the material onto the repaired surface and in full compliance with the technological process.

Also, factors such as improper asphalt paving technology affect the wear of the road surface.

The nuances of laying asphalt

In our country, unfortunately, this is not uncommon. The quality is greatly affected by the fact that asphalt paving takes place in a humid environment, although any builder should be aware that the ingress of moisture into the consistency of the material is not only undesirable, but also harmful. This is especially unfavorable when the moisture that has got inside the canvas freezes and destroys the internal integrity of the road surface, significantly worsening its characteristics.

And of course, when working in wet conditions, it is very difficult to achieve adhesion of the base and the asphalt itself.

Phenomena such as subsidence of soil under the roadway are very common, leading to its deformation in certain areas. Often, the loads on the roadway exceed the maximum allowable according to the calculations of the properties of the material used.

A gust under the groundwater bed has a very bad effect on the quality of the road surface. In such cases, asphalt repair is carried out more thoroughly, often with a complete replacement of not only the asphalt pavement, but the entire foundation of the road. Such repair goes into the category of major repairs, when it is necessary to use a large amount of equipment and building materials.

When to overhaul asphalt

So, major repairs are carried out when very serious solutions to the problems of the roadway are necessary. This repair includes two types of repair:

• First- this is when the topmost layer is removed - asphalt and lining. The damaged area is again covered with sand, filled with various solutions, and then everything is again laid with bitumen. A completely new asphalt surface is being laid on top;
• Second type of overhaul - this is when asphalt repair, in principle, does not make sense in case of large damage, and it remains only to prepare the laying of a new roadway, taking into account the need to comply with all required norms and rules.

But often it is not required, especially in cases where its construction was carried out in full compliance with all necessary standards. If the canvas is damaged, only current repairs are required, which only affect the condition of the asphalt. Asphalt maintenance is usually performed when it is necessary to correct minor flaws, patch up some small details, cover up cracks or eliminate relatively small potholes and holes.

26.03.2019

The requirements for the state of road coverage are clearly spelled out in the relevant regulatory documents (GOST R 50597-93, SNiP 2.07.01 and others). However, they do not take into account the rapid increase in the number of vehicles and the corresponding increase in the load on the road surface. Along with the progress of technology, the number of materials and technologies for road repair is also growing.

In particular, patching of asphalt pavement is justified if the degree of damage allows it. Otherwise, major road repairs should be carried out. Only strict observance of technological conditions and requirements for such repairs provides strong "patches". Let's take a closer look at the technology.

Types of patching

The type of repair required in a particular case depends on the nature and extent of damage to the pavement, the operational load on the pavement (measured in the number of vehicles per day). The procedure is also divided into different types depending on the materials and technologies used:

• Laying hot mix asphalt.
• Hot asphalt paving.
• Casting with a fluid mixture.
• Jet-injection (injector) method.
• Repair with infrared heating units.

Each of the methods has its own advantages and disadvantages and is used depending on a number of factors related to the characteristics of the damaged pavement, the climatic conditions of the region, and even the budget allocated for the work. Efficiency of work is not the last indicator that affects the choice of technology. For example, patching with poured asphalt in winter is unacceptable due to high humidity.

The preferred technology and material must meet a number of criteria:

• Correspondence of the surface properties of the finished patch and the base coat.
• Correspondence of the strength of the asphalt concrete mix to the operational loads on the repaired site.
• Availability and accessibility of materials and technical means for repairs.
• Material requirements for weather conditions during repairs.
• Efficiency of resumption of traffic upon completion of work and overall speed of execution.
• Economic features of a particular method of performing work.

New Asphalt Technologies – NovTecAs is a company engaged in road and road patching, asphalt laying and related activities in Moscow.

Technology features

The technologies of the methods mentioned above differ in some details, but there are a number of general requirements that govern the performance of any type of repair. First of all, it must be carried out under appropriate weather conditions: the air temperature is at least 5ºС and in the absence of precipitation.

The exception is hot asphalt mixes, which can be worked with at 0ºС, but only in the presence of special additives and with a layer thickness of more than 4 centimeters.

Preparatory work

Before pouring or laying the mixture, it is necessary to prepare the damaged area of ​​\u200b\u200bthe coating. Preparatory work includes:

• Marking of repaired areas;
• Cutting out potholes to the full depth of the pavement, capturing at least 3 cm of whole asphalt around the pit (some technologies involve reusing the cut material);
• Mechanical cleaning of the cut out recess from moving particles (using pneumatic, hydraulic and mechanical devices for removing debris);
• Impregnation of the walls and bottom of the recess with a special preparatory compound or bitumen (depending on the requirements of a particular technology).

Of course, the required amount and types of preparation depend entirely on the chosen method. For example, infrared repair is performed by heating the coating, does not require cutting a pothole.

Laying a section of a new coating

The appropriately prepared pavement is filled with asphalt concrete mixture according to the selected technology. The mixture is poured, poured or sprayed into the recess, and then leveled and compacted.

Road patching technology, which includes recycling, involves the introduction of crushed old pavement into a fresh mixture to reduce material costs. In the case of using the jet-injection method, all preparatory and basic processes are performed using one installation, but the method has its limitations.

After the repair is completed, the patch should acquire operational properties within a period of time corresponding to the characteristics of the material used.

Asphalting with hot mixes

Hot mix asphalt can be free-flowing or flowable. Laying the heated material ensures its increased adhesion to the base.

Asphalt for casting has a pasty consistency and fills the unevenness of the base under the influence of gravity. In addition, poured asphalt does not require mechanical compaction, since it acquires the necessary density during the cooling process. On the other hand, such asphalt softens during the hot season, which leads to the formation of ruts.

Loose hot sweep of bitumen with aggregate of a certain fraction and type (sand, crushed stone) have their own advantages. First of all, not expensive transportation. At the same time, the technology of laying loose hot mixes involves the use of vibrotamping manual units or massive rollers, which complicates the technological process and increases the time spent on work.

Stored cold mix asphalt differs in paving temperature and, to a large extent, in composition. Modified bitumen and special additives expand the range of climatic conditions, allowing asphalting at temperatures down to -10ºС. Moreover, the packaged organo-mineral mixture:

• Does not require special equipment (except for a gas burner for heating the surface);
• Can fit into potholes without pre-cutting;
• No special requirements for transportation;
• Does not require special qualifications of the workforce.

On the other hand, the laid and compacted organo-mineral mixture is characterized by low shear resistance, which does not allow it to be laid in places where vehicles decelerate. The combination of price and quality of the material characterizes it as a means to quickly eliminate potholes when winter comes, that is, outside the traditional roadworks season and a means of preventing damage from increasing in winter.

The injection or jet-injection method is a special case of working with cold asphalt mixes. Appropriate installations (for example, UYAR-1 or foreign analogues) allow you to quickly repair small and medium damage to the road surface even without cutting. A single unit performs all the preparatory and main stages of the repair, and additional compaction is not required due to the application of the mixture under pressure.

There are several types of cold mix asphalt:

1. With emulsion for immediate use. Mixtures of this type, as a rule, are used for repairs by the injection method. A portion of the prepared mixture is placed in the tank of the unit before the start of the shift.
2. Emulsion mixtures with mineral additives.
3. Packaged stored organic mixture. In packaged form, such a mixture can be stored for up to 8 months and retain its properties after breaking the packaging for up to two months.

There are other, highly specialized types of mixtures, but they are used much less frequently than those listed above.

Quality control

After the patching of the road surface is completed, visual and instrumental quality control (GOST 310515, SNiP 3.06.03 and others) of the patch is carried out according to the following parameters:

• strength;
• Coating thicknesses;
• The presence of defects (drawdowns, etc.)
• planes;
• Coating roughness.

The results of the control are compared with the regulatory documentation, and based on the comparison, the quality of the work is determined.

P a simple solution to an age-old problem

G The main difference between the current repair of asphalt and the overhaul is the possibility of its implementation without a complete replacement of the pavement, that is, many times faster and cheaper, but with a good practical result (with the restoration of up to 85% of the functional characteristics of the new pavement). At the same time, I would like to emphasize that the current repair is not a forced half-measure - it is a kind of full-fledged road repair.

Depending on the goals pursued by him, the current repair of asphalt is usually divided into three main groups:

• fissure (sealing of cracks of established thickness and depth);
• patching (elimination of large potholes);
• carpet (local renewal of the asphalt road by smoothing the so-called "wear carpets").

Pothole repair is the most common among all of the above. It is used everywhere - both on city streets, and on local roads, and on suburban highways. The positive effect of it is high, regardless of the general condition of the pavement being repaired. Unless, of course, the repair was carried out in accordance with the established technology.

Pothole repair as the professionals see it

The technological sequence of patching production is quite simple:

• cleaning the pothole from debris, dust, soil, asphalt crumb (cleaning is carried out by the compressor method - “purging”);
• heating the edges of the pothole (necessary to improve adhesion);
• filling the pothole with an asphalt mixture (with a preliminary application of a bituminous emulsion);
• rolling of the surface (contributes to the leveling and compaction of the asphalt mixture).

TYPICAL TECHNOLOGICAL CHART (TTK)

I. SCOPE

I. SCOPE

1.1. A typical technological map (hereinafter referred to as TTK) is a comprehensive organizational and technological document developed on the basis of methods of scientific organization of labor, intended for use in the development of Work Production Projects (PPR), Construction Organization Projects (POS) and other organizational and technological documentation in construction.

TTC can be used for the proper organization of labor at a construction site, determining the composition of production operations, the most modern means of mechanization and methods for performing work according to a specific technology.

The TTK is an integral part of the Work Execution Projects (hereinafter referred to as the PPR) and is used as part of the PPR in accordance with MDS 12-81.2007.

1.2. This TTK provides guidance on the organization and technology of patching asphalt concrete pavements with hot asphalt mix.

The composition of production operations, requirements for quality control and acceptance of work, planned labor intensity of work, labor, production and material resources, measures for industrial safety and labor protection were determined.

1.3. The regulatory framework for the development of a technological map are:

- standard drawings;

- building codes and regulations (SNiP, SN, SP);

- factory instructions and specifications (TU);

- norms and prices for construction and installation works (GESN-2001 ENiR);

- production norms for the consumption of materials (NPRM);

- local progressive norms and prices, labor costs norms, material and technical resources consumption norms.

1.4. The purpose of creating the TTC is to describe solutions for the organization and technology of patching asphalt concrete pavements with hot asphalt concrete in order to ensure their high quality, as well as:

- cost reduction of works;

- reduction of construction time;

- ensuring the safety of work performed;

- organization of rhythmic work;

- rational use of labor resources and machines;

- unification of technological solutions.

1.5. On the basis of the TTK, as part of the PPR (as mandatory components of the Work Execution Project), Working Technological Charts (RTK) are developed for the performance of certain types of work (SNiP 3.01.01-85 * "Organization of construction production") for patching asphalt concrete pavements with hot asphalt concrete mix.

The design features of their implementation are decided in each case by the Working Design. The composition and level of detail of materials developed in the RTK are established by the relevant contracting construction organization, based on the specifics and scope of work performed.

RTK are considered and approved as part of the PPR by the head of the General Contractor Construction Organization.

1.6. TTK can be tied to a specific object and construction conditions. This process consists in clarifying the scope of work, means of mechanization, the need for labor and material and technical resources.

The procedure for linking the TTK to local conditions:

- consideration of map materials and selection of the desired option;

- verification of the compliance of the initial data (volumes of work, time standards, brands and types of mechanisms, building materials used, composition of the worker link) to the accepted option;

- adjustment of the scope of work in accordance with the chosen option for the production of work and a specific design solution;

- recalculation of costing, technical and economic indicators, the need for machines, mechanisms, tools and material and technical resources in relation to the chosen option;

- design of the graphic part with a specific binding of mechanisms, equipment and fixtures in accordance with their actual dimensions.

1.7. A standard flow chart has been developed for the maintenance and current repair of public roads in the spring, summer and autumn periods of operation and is intended for engineering and technical workers (foremen, foremen) and workers performing work in the II road-climatic zone, in order to familiarization (education) of them with the rules for the production of patching of asphalt concrete pavements with hot asphalt concrete mix, using the most progressive and rational solutions for the organization, technology and mechanization of road works.

II. GENERAL PROVISIONS

2.1. The technological map has been developed for a set of works on patching asphalt concrete pavements with hot asphalt concrete mix.

2.2. Works on patching of asphalt concrete pavements with hot asphalt concrete mix are carried out in one shift, the duration of net working time during a 10-hour shift is:

2.3. The scope of work consistently performed during patching of asphalt concrete pavements with hot asphalt concrete mix includes the following technological operations:

- placement of road signs at the repair site;

- preparation of coverage areas for repair;

- processing of prepared repair maps with bituminous emulsion;

- laying hot asphalt mix in the repair card;

- compaction of the place of repair.

2.4. The technological map provides for the performance of work by an integrated, specialized team consisting of: dump trucks KAMAZ-55111 (Q=13.0 t); vibrating plate TSS-VP90N (weight P=90 kg, compaction depth h=150 mm up to Ku=0.95); Atlas Copco XAS 97 Dd mobile compressor ( compressed air supply 5.3 m/h, =0.7 MPa, m=940 kg); jackhammer MO-2K (weight m=10 kg, =0.5 MPa, impact frequency 1600 bpm); floor saw MASALTA MF14-4 (=24.534.0 cm, cutting depth=90 mm, weight m=83 kg, manual control); mobile bituminous boiler volume 200 l; Bobcat S570 mini loader with skid steer (operating weight = 2900 kg, load capacity = 944 kg, = 62 hp, bucket height h = 3023 mm).

Fig.3. Mini Loader Bobcat S570

Fig.8. Asphalt Concrete Tools

1 - rake; 2 - leveler of the mixture; 3 - ironer

Fig.9. Asphalt Concrete Tools

1-4 - watering cans; 5 - scoop

2.5. The following building materials are used for the repair of asphalt concrete pavements: bitumen emulsion EBDC B, meeting the requirements of GOST R 55420-2013; hot, asphalt concrete, fine-grained mix type B grade II, meeting the requirements of GOST 9128-2013.

2.6. Works on patching asphalt concrete pavements with hot mix asphalt should be carried out in accordance with the requirements of the following regulatory documents:

- SP 48.13330.2011 "SNiP 12-01-2004 Organization of construction. Updated edition";

- SP 34.13330.2012. "SNiP 2.02.05-85 *. Highways. Updated edition";

- SP 78.13330.2012 "SNiP 3.06.03-85. Highways. Rules for the production of works. Updated edition";

- STO NOSTROY 2.25.37-2011. "The device of asphalt concrete pavements of highways Part 2. The device of asphalt concrete pavements from hot asphalt concrete";

- STO NOSTROY 2.25.47-2011. "Repair of asphalt concrete pavements of highways. Part 1. General provisions";

- ODMD-2004. "Guidelines for the repair and maintenance of public roads";

- ODM 218.0.000-2003. "Guidelines for assessing the level of maintenance of highways" ;

- VN 10-87 "Instruction for assessing the quality of the maintenance (condition) of highways";

- GOST R 55420-2013. "Public automobile roads. Cationic bituminous emulsions. Specifications";

- GOST 9128-2013. "Asphalt-concrete polymer-asphalt-concrete mixes, polymer-asphalt-concrete asphalt concrete for highways and airfields. Specifications";

- GOST 10807-78*. "Road signs. General specifications";

- GOST R 50597-93. "Requirements for the operational state, admissible under the conditions of ensuring road safety";

- SNiP 12-03-2001 "Labor safety in construction. Part 1. General requirements";

- SNiP 12-04-2002 "Labor safety in construction. Part 2. Construction production";

- NPO ROSDORNII-1993 "Rules for labor protection in the construction, repair and maintenance of roads";

- RD 11-02-2006 "Requirements for the composition and procedure for maintaining as-built documentation during the construction, reconstruction, overhaul of capital construction facilities and the requirements for certificates of examination of works, structures, sections of engineering and technical support networks";

- RD 11-05-2007 "Procedure for maintaining a general and (or) special journal for recording the performance of work during construction, reconstruction, overhaul of capital construction projects";

- MDS 12.-29.2006 "Methodological recommendations for the development and execution of a technological map";

- Order of the Ministry of Transport of Russia N OS-854-R dated 09.10.2002 "Methodological recommendations for the development of a road maintenance project".

III. ORGANIZATION AND TECHNOLOGY OF WORK PERFORMANCE

3.1. In accordance with SP 48.13330.2001 "SNiP 12-01-2004 Organization of construction. Updated edition" prior to the commencement of construction and installation works at the facility, the Contractor is obliged to obtain from the Customer project documentation and permission to perform construction and installation works in the prescribed manner. Work without permission is prohibited.

3.2. Prior to the start of patching work, it is necessary to carry out a set of organizational and technical measures, including:

- to conclude a contract with the technical Customer (road management authority) for the performance of work on the maintenance of a section of the highway and road structures on it;

- to receive from the technical Customer (road management authority) the Current plan containing the task on the quality of the maintenance of the section of this highway and road structures;

- receive from the technical Customer (road management authority) an approved and agreed "Project for the maintenance of a public highway";

- develop a WEP for the maintenance and current repair of a section of the road, containing decisions on the organization of construction production and the technology of road construction work, coordinate it with the construction control of the Customer (road management authority) and the General Contractor (Unitary road maintenance enterprise);

- solve the main issues related to the logistics of work, incl. conclusion of contracts for the supply of material and technical resources, placement of orders for the manufacture of elements of prefabricated structures, parts and products necessary for the maintenance of the road;

- organize a thorough study of the above, design materials, foremen and foremen of the construction organization;

- appoint by order of the construction organization persons responsible for the safe production of work, control and quality of their implementation;

- to equip the brigade (link) with workers of relevant professions and machinists of road-building machines with the necessary qualifications;

- to acquaint the foremen and link officers with the Project for the production of works, the technology of work on the current repair of the highway, and also to issue to the teams and links Orders-assignments, Calculations and Limit-fence cards for materials for the entire volume of assigned work;

The task order indicates the types of work performed in this area, their volume, production rates, the required amount of working time to complete the entire scope of work, the amount of piecework earnings, as well as the conditions for bonuses to the work brigade;

- to instruct the members of teams (links) on industrial safety and labor protection during the performance of work;

- provide workers with personal protective equipment;

- establish temporary inventory household premises for the storage of building materials, tools, inventory, heating workers, eating, drying and storing work clothes, bathrooms, etc.;

- develop schemes and arrange temporary access roads for traffic to the place of work;

- arrange temporary storage areas for receiving structures, building parts and materials;

- prepare for the production of machines, mechanisms and equipment provided for by the PPR, deliver them to the facility, mount and test them at idle;

- deliver to the work area the necessary equipment, devices for safe work performance, electrified, mechanized and hand tools;

- provide the construction site with fire-fighting equipment and signaling equipment;

- provide communication for operational and dispatching control of the production of works;

- draw up an act of readiness of the enterprise for the production of work;

- obtain permission from the technical supervision of the Customer to start work.

3.3. General requirements for the performance of work

3.3.1. Road maintenance includes a set of engineering and technical measures and works for the systematic maintenance of the road, road structures and the right of way, in order to prevent and maintain them in good order throughout the year and correct minor deformations and damage to all structural elements, as well as organizing and ensuring traffic safety.

The performance of maintenance work in full and with high quality slows down the process of deterioration of the transport and operational indicators of the road.

3.3.2. The maintenance task is to ensure the safety of the road and road structures and maintain their condition in accordance with the requirements permissible under the conditions for ensuring continuous and safe traffic at any time of the year.

3.3.3. Works on the maintenance of road facilities are carried out taking into account the season and the following periods of the year:

- spring period - March, April, May;

- winter period - December, January, February;

- summer period - June, July, August;

- autumn period - September, October, November.

3.3.4. Pavement maintenance work includes:

- cleaning of road surfaces from debris, dust and dirt, cleaning of foreign objects, elimination of slipperiness caused by bitumen sweating;

- elimination of small deformations and damages (sealing of potholes, subsidence, etc.), correction of edges (curbs) on all types of pavements, filling cracks in asphalt concrete and cement concrete pavements, restoration and filling of expansion joints in cement concrete pavements;

- repair of chips and breaks of cement concrete pavement slabs, replacement, lifting and leveling of individual slabs;

- protection of cement-concrete coatings from surface damage;

- arrangement of protective layers of emulsion-mineral mixtures in areas of peeling and chipping of asphalt concrete and cement concrete coatings;

- elimination of ruts up to 30 mm deep by laying two layers of emulsion-mineral mixture or surface treatment along rolling strips up to 0.8 m wide;

- partial milling or cutting of ridges and irregularities along the ruts with filling the ruts with black gravel or asphalt concrete and the installation of a protective layer of the emulsion-mineral mixture over the entire width of the coating;

- stopping and preventing the development of cracks and a network of cracks by installing an insulating layer of fine-grained surface treatment using local maps;

- restoration of worn upper layers of asphalt concrete pavements and laying them again on separate small (up to 20 m) sections of the road;

- correction of the profile of crushed stone and gravel coatings with the addition of crushed stone or gravel;

- profiling of unpaved and unpaved improved roads, restoration of the profile and improvement of their carriageway with crushed stone, gravel, slag and other materials with a flow rate of up to 100 m per 1 kilometer;

- dedusting of roads;

- maintenance of road sections with heaving and weak soils.

3.3.5. V spring period(before the start of intensive melting), snow and ice must be removed from the roadway and roadsides. After drying, the coating is thoroughly cleaned of dirt, dust, anti-icing materials using various means of harvesting mechanization.

In spring, during the period of maximum wetting of the subgrade, special attention is paid to the protection of coatings from destruction. The road service, on the basis of passport data or the results of an assessment, must determine the largest loads that can be missed on the serviced roads.

On weakened areas, especially on roads with lightweight types of coatings (wetting of the subgrade, abysses), measures are taken to increase the bearing capacity of the road structure by laying shields, brushwood, boards, drainage soil, followed by their cleaning after restoring the strength of the road structure. If it is impossible to fulfill them or if they are insufficiently effective, they restrict the movement of heavy vehicles, reduce speed or completely close the passage, transferring it to specially prepared bypasses. When organizing these events, be guided by special documents for restricting or closing traffic on roads.

In the spring, from the moment warm and stable weather sets in, they begin to eliminate minor damage in the form of potholes, cracks, individual waves, bumps and swells, etc.

3.3.6. V summer period perform work on cleaning the carriageway from dust and dirt, especially in adverse weather conditions. Cleaning is carried out with mechanical brushes, watering and washing and sweeping machines.

3.3.7. Patching repair - repair work that eliminates defects on the coating in the form of potholes, individual waves, influxes, bumps, etc.

The task of patching is to restore the continuity, evenness, strength, adhesion and water resistance of the coating and ensure the standard service life of the repaired areas.

As a rule, all patching work is carried out in early spring, as soon as weather conditions and pavement conditions allow. In summer and autumn, potholes and pits are sealed immediately after they appear.

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

hot ways are based on the use of hot asphalt mixes as a repair material: fine-grained, coarse-grained and sandy mixes, poured asphalt concrete, etc. Hot patching methods ensure higher quality and longer service life of the repaired pavement.

Hot patching is used in the repair of roads with asphalt concrete pavement and is performed using two components - bituminous emulsion and hot asphalt mix. The composition and properties of the asphalt mix used for repair should be similar to the one from which the coating is made.

Bituminous road emulsion- it is a homogeneous low-viscosity liquid of dark brown color, which is obtained by fine grinding of bitumen in an aqueous solution of a surfactant (emulsifier). Due to its low viscosity, this material is used as a film-forming or binder material, which provides the most favorable conditions for the treatment of road surfaces. The undeniable advantages of road bitumen emulsion include: environmental friendliness, safety and durability. It is actively used both on concrete and on asphalt and gravel coatings.

High-density and dense hot asphalt concrete mixes of types A and B- these are rationally selected mixtures of crushed stone, sand (natural or from screenings of crushing), mineral powder and road bitumen (with or without additives), mixed in a heated state, laid with a thickness exceeding the maximum size of crushed stone by at least 2-2.5 times.

Hot asphalt mixes are used, as a rule, mainly in the repair of road surfaces of categories I-II.

Works can be carried out at an air temperature of at least +10°C with a thawed base and a dry coating. When using a heater of the repaired coating, it is allowed to carry out repairs at an air temperature of at least +5°С.

3.4. Preparatory work

3.4.1. Prior to the commencement of works on patching of asphalt concrete pavements with hot asphalt concrete mix, the preparatory work provided for by the TTC must be completed, including:

- with a representative of the technical supervision of the Customer, an inspection of the road section was carried out to assess the condition and determine the types, volumes and technology of work required for the complete and high-quality elimination of the identified defects and damage to the pavement;

- the results of regular inspections of the road section and structures, carried out by representatives of the General Contractor (Unitary Road Maintenance Enterprise) and entered in the Journal of Daily Inspections of the State of the Road, Arrangement Elements and Structures, were studied;

- analyzed the identified defects and inconsistencies with the level of maintenance and regulatory requirements, the amount of repair work;

- based on the analysis and technical inspection of the identified inconsistencies, draw up a defective statement, which serves as the basis for determining and planning work, an assessment of the technical condition of the road section, structure is given;

- on the basis of a defective statement, develop and approve with the technical Customer for the execution of work the necessary calculations of the need for labor, production and material resources, estimates and drawings;

- re-examine the road section with the representative of the Customer's technical supervision in order to clarify the design solutions and identify additional work missed or not taken into account by the project and estimates;

- road signs and fences of the work site were placed according to the scheme.

3.4.2.

Asphalt pothole repair is a type of current repair of asphalt concrete pavement. This method is associated with the reconstruction of sections of the roadway by replacing the pavement in these same sections.
This type of repair of asphalt concrete pavements, such as patching, allows you to eliminate various damage to the roadbed with an area of ​​​​up to 25 m², for example, potholes, single cracks, peeling of the site, waves on the road, asphalt subsidence and many others.
The technology of patching the pavement consists in rolling asphalt mixtures and involves following the following steps:

• determination of the boundaries on which the repair will be carried out;
• cutting out the coating in the required place of repair;
• complete removal of the coating material;
• application of asphalt mix;
• compaction of the coating and its alignment.

When choosing the boundaries of the patching of asphalt pavements, it should be taken into account that the destruction on the base of the pavement under the defect of the canvas covers much larger frames than the actual destroyed zone. In general, the geometric dimensions of the "patch" should be in accordance with the zone of the destroyed state. Not less than 15 centimeters, the contour of the "patch" should overlap the destruction zone, and preferably even 20-30 centimeters.
Often the width of the "patch" is equated to the width of the lane (with extensive cracks, wide potholes, breaks, as well as other damage that takes up most of the lane), with smaller damage, this zone may be smaller than the zone of the lane, but more than 100 mm.

Places for repair make any contour, but without sharp corners, most often they are rectangular in shape, which is more convenient for repairs. In order to cut the coating at the repair site, it is necessary to use a jackhammer or joint cutter. If you use a jackhammer when processing the outer boundaries of the “patch”, practice shows that later these very boundaries are chipped. This has a very bad effect on the service life of the repaired coating.

If a seam cutter is used, then a jackhammer is used to break the coating and remove it from the "patch". The coating material is removed manually. Asphalt mixture is laid in ready-made patches. The compaction of such a mixture is carried out by a vibrocompactor.

Capital repairs of roads

Capital repair of roads is a whole range of works to fully restore and improve the performance of the road surface, subgrade, structures on the road, replacing old worn-out structures or parts with stronger and more durable ones. If necessary, the geometric parameters of the road are increased, here it is necessary to take into account the intensity of traffic on the road and the axle loads of vehicles within the limits that correspond to certain categories established for repair cases. The width of the subgrade does not change throughout the entire route. Today, the roads are very loaded, and, no matter how they are treated, repairs are needed in a timely manner.

Our climate in its own way affects the condition of the road surface. Cracks that appear on the pavement are not at all an indicator of poor road construction work. To a large extent, the climate influences - snowy winters with thaws. That is, the destruction of roads is quite natural and inevitable.

The main objective of the road overhaul is to restore the transport and operational potential of the road to the level at which it will comply with the measures of safe traffic on it.
The criterion that it is already necessary to resort to a major overhaul of the road is the transport and operational condition of the poured asphalt, in which the strength parameter has dropped to the limit value.
Major repairs of the road, as in the case of construction, must be carried out on all sections of this road, all structures and elements along the entire length of the asphalted area.
Capital repairs, as well as road construction, are carried out in full accordance with specially developed and approved design estimates.