Current repair of asphalt concrete coating. Measuring repair of asphalt
What are the norms, which is attributed to overhaul, and what to the current. Namely, the repair of asphalt coating is it possible to carry out current repairs and with payment on OMS?
Answer
The repair of the asphalt coating at the expense of OMS is possible only within the framework of the current repairs. If the coating repairs are carried out within the framework of major repairs, it is impossible to pay for repair at the expense of the OMS.
If establishing several sources of financing and these costs are associated with the activities of the institution on other KFOs, expenses should be expected at the expense of various KFOs. Method of distribution of expenses Install in the accounting policy of the institution.
The institution independently determines which repairs refer to current, and which are to capital, since these issues are not regulated by the legislation on accounting.
The basis for determining the types of repair should be the relevant documents developed by the technical services of organizations within the planning and preventive repair system. This is stated in the letter of the Ministry of Finance of Russia dated January 14, 2004 No. 16-00-14 / 10. To determine what type of repair includes work, you can be guided by the following documents:
Regulations on the planning-preventive repair of production buildings and structures of MDS 13-14.2000, approved by the Resolution of the USSR State Building dated December 29, 1973 No. 279;
Departmental construction standards (VNC) No. 58-88 (P), approved by the Order of the State Committee for Goscomcolautors under the USSR State Street of November 23, 1988 No. 312;
letter of the USSR Ministry of Finance dated 29.05.1984 No. 80.
This is stated in the letters of the Ministry of Finance of Russia dated February 25, 2009 No. 03-03-06 / 1/87 and from 11/23/2006 No. 03-03-04 / 1/797.
For example, in accordance with the current legislation, work on the elimination of ruts, phases and elevation by displacement, as well as raising the extensions of the fine rubble and sealing of seams and cracks of cement-concrete coatings relate to the current repairs.
The device of the asphalt concrete coating on the roads with cement-concrete coating, the change of cement-concrete coating to the new, enhancement of the asphalt concrete coating, the reorganization of rubbed and gravel coatings, profiling of the dirt roads is overhaul.
Such a conclusion follows from Appendix No. 3 and No. 8 "Regulations on the conduct of planned-preventive repair of production buildings and structures" from 29.12.1973 No. 13-14.2000, 279. Thus, the meal repair of the asphalt coating should be attributed to the current repair .
Justification
From the decision, the provisions, the methodological documentation of the USSR State Construction of December 29, 1973 No. 13-14.2000, 279
MDS 13-14.2000 Regulations on the conduct of planning-preventive repair of production buildings and structures
A. Current repairs
3.4. The current repair of production buildings and structures includes work on systematic and timely protection of parts of buildings and structures and engineering equipment from premature wear through preventive measures and eliminating small damage and malfunction.
List of work on the current
Repair of buildings and structures on buildings
XIX. Car roads
1. Correction of oven with layout and seal.
2. Cleaning drainage channels and cuvettes.
3. The elimination of the rutting, sidelines and elevation by displacement, as well as the place of the sewers of the shallow rubble and sealing the seams and cracks of cement-concrete coatings.
4. References of separate on-board stones.
5. Replacing road signs.
6. Repair of artificial structures in the amount adopted for railway structures. *
List of works on the overhaul of buildings and structures
XIX. Car roads
a) Earthly canvas
1. Treatment of the earth canvas in places of landslides, collaps, blurred and punching.
2. Restoration of all drainage and drainage devices.
3. Restoration of all protective and strengthen structures of the earth canvas.
4. Changing individual structures of artificial structures or replacing them to other designs, as well as the complete change of pipes and small bridges (if they are not independent inventory objects, and are part of the earthen canvase or road as a single inventory object).
b) Roadwear
1. Alignment and replacement of individual cement-concrete slabs.
2. Laying on the cement-concrete coating of the leveling layer of asphalt concrete.
3. The device of the asphalt concrete coating on roads with cement-concrete coating.
4. Change of cement-concrete coating to new.
5. Strengthening asphalt concrete coating.
6. Reconstruction of rubbed and gravel coatings.
7. Mixing bridges.
8. Profiling dirt roads.
c) bridges, pipes
1. Partial overlap of stone and brick supports (up to 20% of the total volume).
2. Repair of concrete supports (up to 15% of the total).
3. Changing damaged elements of wooden bridges, with the exception of piles.
4. Change of wooden or reinforced concrete flooring, as well as the replacement of wooden flooring on the reinforced concrete.
5. Full change or replacement of spans.
6. Packing of pipe glides.
7. Change of elements of wooden, reinforced concrete or concrete pipes (up to 50% of volume).
d) venues for cars, road construction
and other machines, storage sites, as well as sites
break-accepting points
1. Repair and restoration of drainage structures (trays, cuvettes, etc.).
2. Machining of cobblestones.
3. Reconstruction of crushed stone and gravel area coatings.
4. Repair of concrete sites with laying of the aligning layer of concrete.
5. Alignment and replacement of individual cement-concrete slabs.
6. The coating asphalt concrete venues listed in paragraph 2 - 5.
Letter of the Ministry of Finance of Russia dated January 14, 2004 No. 16-00-14 / 10
On determining the type of repair of fixed assets
The Department of Accounting and Reporting Methodology reports that in the preparation of methodological instructions on accounting records of fixed assets approved by the Order of the Ministry of Finance of Russia dated October 13, 2003 No. 91n, in section 5 "Content and restoration of fixed assets" were excluded definitions of repair types, in t. h. capital; Since these issues are not regulated by legislation on accounting. The basis for determining the types of repair should be the relevant documents developed by the technical services of organizations within the planning and preventive repair system.
B. Overhaul
3.11. The overhaul of production buildings and structures includes such work, in the course of which the worn out of the structures and details of buildings and structures are changed or the replacement of them for more durable and economical, improving the operational capabilities of repaired objects, with the exception of the full change or replace the main designs, whose service life The buildings and facilities are the greatest (stone and concrete foundations of buildings and structures, all types of walls of buildings, all types of wall frames, underground networks, bridge supports, etc.).
FFOM letter from 06/06/2013 № 4509/21-and
On issues of consumption of compulsory medical insurance in the framework of the basic health insurance program
The federal fund of compulsory health insurance in connection with the appeals of territorial funds for compulsory health insurance on the spent of compulsory medical insurance funds in the framework of the basic health insurance program reports the following.
According to part 7 of Article 35 of the Federal Law of November 29, 2010 No. 326-ФЗ "On compulsory medical insurance in the Russian Federation" (hereinafter referred to as the Federal Law), the facilities of the Tariff for paying medical care in the framework of the basic health insurance program includes wage costs fee, accrual for remuneration, other payments, acquisition of medicines, consumables, food. Soft equipment, medical instruments, reagents and chemicals, other material reserves, costs for the cost of laboratory and instrumental research conducted in other institutions (in the absence of a laboratory and diagnostic equipment in a medical organization), nutritional organization (in the absence of organized nutrition in a medical organization) , expenses for payment of communication services, transport services, utilities, works and services for the maintenance of property, rental costs for the use of property, payment for software and other services, social security of medical organizations established by the legislation of the Russian Federation, other expenses, expenses For the purchase of equipment worth up to one hundred thousand rubles per unit.
In accordance with Part 1 of Article 30 of the Federal Law, tariffs for medical care are calculated in accordance with the methodology for calculating tariffs for medical assistance approved by an authorized federal executive body as part of the rules of compulsory medical insurance, and include the costs of the costs established by the territorial program of the mandatory medical insurance.
Medical organizations are obliged under paragraph 5 of part 2 of Article 20 of the Federal Law to use the means of compulsory medical insurance obtained for the medical assistance provided in accordance with the Mandatory Medical Insurance Programs.
In determining the appropriate areas of consumption of funds, instructions should be guided by the instructions on the application of the budget classification of the Russian Federation for 2013 and on the planning period of 2014 and 2015 (hereinafter referred to as instructions), approved by the Order of the Ministry of Finance of the Russian Federation of December 21, 2012 No. 171n. The classification of fixed assets included in the depreciation groups approved by the Decree of the Government of the Russian Federation No. 1 from January 1, 2002 No. 1 (hereinafter referred to as the classification of fixed assets) and the All-Russian Classifier of the Fund 13-94, approved by the Resolution of the Russian State Standard of December 26, 1994 No. 359.
Overhaul costs include the stand of 225 "works, services for the content of the property" Article 220 "Payment of works, services" Kward and according to a letter of the Ministry of Health of the Russian Federation of December 25, 2012 "On the formation of the Ministry of Health of the Russian Federation No. 11-9 / 10 / 2-5718 and the economic justification of the territorial program of state guarantees of free provision of medical care for 2013 and for the planning period 2014 and 2015 "are not included in the facilities for paying for medical care in the framework of the basic health insurance program.
The concept of capital construction of capital construction objects is given in paragraph 14 of Article 1 of the Town Planning Code of the Russian Federation, approved by the Federal Law of December 29, 2004 No. 190-FZ (with changes and additions).
Current repairs are subject to Storetia 225 "Works, services for the content of the property" Article 220 "Payment of works, services" of the COS and are included in the Tariff for paying medical assistance in the framework of the basic health insurance program.
What expenses can be made at the expense of the OMS
The structure of the tariff for paying for medical care in terms of the basic program includes the costs specified in paragraph 7 of Article 35 of the Law of November 29, 2010 No. 326-FZ. In particular, the tariff includes:
expenses for salary and accrual for labor;
acquisition of medicines, consumables, food, soft equipment, medical instruments, reagents and chemicals;
costs of payment for the cost of laboratory and instrumental studies conducted in other institutions (in the absence of a laboratory and diagnostic equipment in the medical institution);
costs for the organization of nutrition (in the absence of organized nutrition in a medical institution);
acquisition of fixed assets (equipment, industrial and economic equipment) worth up to 100,000 rubles.
In addition, other expenses may be included in the cost of rendering medical assistance in accordance with the legislation on the OMS. So, the FFOMS in a letter dated June 6, 2013 No. 4509/21 clarified that other expenses can be attributed to:
compensation to citizens of moral and physical harm in connection with the poor quality of medical assistance;
payment of taxes, fines and penalties;
Social security of medical institutions, etc.
Typical Technology Card (TTK)
I. Scope
I. Scope
1.1. Typical technological map (hereinafter referred to as the TTK text) - a comprehensive organizational and technological document developed on the basis of the methods of the scientific organization of labor intended for use in the development of projects of work (PPR), construction organization projects (POS) and other organizational and technological documentation in construction.
The TTK can be used for the proper organization of labor on a construction site, determining the composition of production operations, the most modern means of mechanization and methods for performing work on a particularly given technology.
TTK is an integral part of the work projects (hereinafter referred to as the PPR) and is used as part of the PPR according to MDS 12-81.2007.
1.2. In this TTK, instructions on the organization and technology of production of work on the invert repair of asphalt concrete coatings are hot asphalt concrete mixture.
The composition of production operations, requirements for quality control and acceptance of works, the planned labor-intensity of works, labor, industrial and material resources, industrial safety measures and labor protection are determined.
1.3. The regulatory framework for the development of a technological card is:
- typical drawings;
- Construction standards and rules (SNiP, CH, SP);
- factory instructions and technical conditions (TU);
- norms and rates for construction and installation work (GESN-2001 Yenir);
- production rates of consumption of materials (NRRM);
- Local progressive norms and rates, labor costs, the rate of consumption of material and technical resources.
1.4. The purpose of the TTK is a description of the decisions on the organization and technology of manufacturing work on the patch repair of asphalt concrete coatings with a hot asphalt concrete mixture, in order to ensure their high quality, as well as:
- reducing the cost of work;
- reduction of construction duration;
- ensuring the safety of the work performed;
- organization of rhythmic work;
- rational use of labor and machines;
- Unification of technological solutions.
1.5. On the basis of the TTK in the composition of the PPR (as the mandatory components of the project's work project) are developed working technological maps (RTK) to perform certain types of work (SNiP 3.01.01-85 * "Organization of construction production") on the patch repair of asphalt concrete coatings with a hot asphalt concrete mixture.
The design features of their execution are solved in each particular case of the work project. The composition and degree of detailing materials developed in RTK are established by the corresponding contract construction organization, based on the specifics and volume of work performed.
RTC is considered and approved as part of the PPR by the head of the General Contracting Construction Organization.
1.6. TTK can be tied to a specific object and conditions of construction. This process is to clarify the amount of work, means of mechanization, the need for labor and material and technical resources.
Procedure for binding TTK to local conditions:
- consideration of card materials and choosing the desired version;
- checking the compliance of the initial data (work volumes, time standards, brands and types of mechanisms used by building materials, the composition of the workers' link) adopted option;
- adjustment of work volumes in accordance with the selected version of the work of work and a specific project decision;
- crosses the calculation, technical and economic indicators, the need for machines, mechanisms, tools and logistical resources in relation to the chosen version;
- Registration of the graphic part with a specific binding of mechanisms, equipment and devices in accordance with their actual dimensions.
1.7. The typical technological card was developed for the maintenance and maintenance of public roads in the spring, summer and autumn periods of operation and is intended for engineering and technical workers (manufacturers of works, masters) and workers performing work in the II road-climatic zone, with a view to Familiarization (learning) of them with the rules for the production of works on the smelting repair of asphalt concrete coatings with a hot asphalt concrete mixture, using the most progressive and rational solutions for the organization, technology and mechanization of road works.
II. General provisions
2.1. The technological card is developed for a complex of work on the hole repair of asphalt concrete coatings with a hot asphalt concrete mixture.
2.2. Work on the patch repair of asphalt concrete coatings with a hot asphalt concrete mixture is performed in one shift, the duration of pure working time for a 10-hour shift is:
2.3. The work that serves asphalt coatings consistently performed with a hot asphalt concrete coatings, includes the following technological operations:
- alignment of road signs at the repair site;
- preparation of coverage for repair;
- processing of a bitumen emulsion of prepared repair cards;
- laying a hot asphalt concrete mix in repair card;
- Sealing the place of repair.
2.4. The technological card provides for the execution of works of a complex, specialized brigade in the composition: car dump trucks KAMAZ-55111
(Q \u003d 13.0 t); tSS-VP90N vibratinglitis
(weight p \u003d 90 kg, depth of sealing H \u003d 150 mm to ku \u003d 0.95); mobile compressor ATLAS COPCO XAS 97 DD
(supply of compressed air 5.3 m / h, \u003d 0.7 MPa, M \u003d 940 kg); jackhammer
MO-2K.
(Mass m \u003d 10 kg, \u003d 0.5 MPa, frequency of shocks 1600 ° C. / min); masalta MF14-4 seams
(\u003d 24.534.0 cm, the depth of propyl \u003d 90 mm, the mass M \u003d 83 kg, manual control); bitumen mobile boiler
volume of 200 l; bobcat S570 Mini Loader
With onboard rotation (operational mass \u003d 2900 kg, carrying capacity \u003d 944 kg, \u003d 62 hp, height of the lattice of the bucket H \u003d 3023 mm).
|
Fig.1. AVTOSMOSMA KAMAZ-55111 |
Fig.2. TSS-VP90T vibratinglitis |
Fig.3. Bobcat S570 Mini Loader
|
Fig.4. Masalta MF14-4 seams |
Fig.5. Bituminous boiler |
|
Fig.6. ATLAS COPCO XAS 97 DD Compressor |
Fig.7. Jackhammer MO-2K |
Fig.8. Asphalt Tools
1 - rake; 2 - miller of the mixture; 3 - ironing
Fig.9. Asphalt Tools
1-4 - Waters; 5 - Cupac.
2.5. The following building materials are applied to repair coatings from asphalt concrete mixtures: bitumen Emulsion EBDC B,
meets the requirements of GOST R 55420-2013; hot
asphalt concrete, fine-grained mixture
type b brand II,
Meeting the requirements of GOST 9128-2013.
2.6. Work on the patch repair of asphalt concrete coatings with a hot asphalt concrete mixture should be performed, guided by the requirements of the following regulatory documents:
- SP 48.13330.2011 "Snip 12-01-2004 Organization of construction. Actualized edition";
- SP 34.13330.2012. "SNiP 2.02.05-85 *. Automobile roads. Actualized editors";
- SP 78.13330.2012 "SNiP 3.06.03-85. Automobile roads. Rules for the production of works. Actualized editors";
- One hundred nostroy 2.25.37-2011. "The device of asphalt concrete coatings of automobile roads Part 2. The device of asphalt concrete coatings of hot asphalt concrete";
- One hundred nostroy 2.25.47-2011. "Repair of automotive asphalt concrete coatings. Part 1. General Provisions";
- ODSD-2004. "Methodical guidelines for the repair and maintenance of public roads";
- ODM 218.0.000-2003. "Guidelines for the assessment of the level of road maintenance";
- VN 10-87 "Instructions for assessing the quality of the content (state) of highways";
- GOST R 55420-2013. "Commercial use roads. Bituminous cationic emulsions. Technical conditions";
- GOST 9128-2013. "Mixtures asphalt concrete polymesphalt concrete, asphalt polymerasfalit concrete for roads and airfields. Technical conditions";
- GOST 10807-78 *. "Road signs. General technical conditions";
- GOST R 50597-93. "Requirements for the operational state, permissible under the conditions for 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";
- NGO Rosornia-1993. "Rules for labor protection in the construction, repair and maintenance of roads";
- RD 11-02-2006 "Requirements for the composition and procedure for conducting executive documentation during construction, reconstruction, overhaul of capital construction facilities and requirements for acts of examination of works, structures, sections of engineering and technical support networks";
- RD 11-05-2007 "The procedure for maintaining a general and (or) special journal of accounting for the construction of work during construction, reconstruction, overhaul of capital construction facilities";
- MDS 12.-29.2006 "Methodical recommendations for the development and design of a technological map";
- Order of the Ministry of Transport of Russia N OS-854-R of 09.10.2002 "Methodical recommendations for the development of a road maintenance project."
III. Organization and technology for performing work
3.1. In accordance with the SP 48.13330.2001 "SNIP 12-01-2004 Organization of construction. Actualized editors" Prior to the start of construction and installation work at the facility, the Contractor is obliged in the prescribed manner to receive project documentation from the Customer and permission to carry out construction and installation work. Performing work without permission is prohibited.
3.2. Prior to the production of work on patching, it is necessary to hold a set of organizational and technical events, including:
- to conclude with the technical customer (road management body) contract for the implementation of the maintenance of the road and road structures on it;
- get from the technical customer (road management body) the current plan containing a task for the quality of the content of the section of this highway and road structures;
- get from the technical customer (road management body) approved and consistent "project of the maintenance of a public road";
- Develop a PPR on the maintenance and current repair of the section of the road, containing solutions for the organization of construction production and the technology of road construction work, coordinate it with the construction control of the Customer (road management body) and the general contractor (unitary road-based operational enterprise);
- solve the main issues related to the material and technical support of work, incl. conclusion of contracts for the supply of material and technical resources, placing orders for the manufacture of elements of prefabricated structures, parts and products required for the maintenance of the road;
- to organize a thorough study of the above, design materials, craftsmen and manufacturers of construction organization;
- to appoint an order to the construction organization of persons responsible for the safe production of works, control and quality of their implementation;
- staffing a brigade (link) working relevant professions and machinists of road construction vehicles necessary qualifications;
- to familiarize yourself with brigadiers and links with the project production project, the technology of work on the current repair of the automotive road, as well as give the brigades and links of tasks, calculation and limit-fence cards to materials for the entire volume of charged work;
In the task, the types of work performed in this area are indicated, their volume, the rules of development, the required amount of working time to perform the entire amount of work, the amount of a piecework earnings, as well as the conditions for the bonuses of workers brigades;
- to conduct a briefing of members of the Brigad (links) on industrial safety and labor protection when performing work;
- to provide workers in individual protection;
- establish temporary inventory household premises for storing building materials, tools, inventory, workers heating, food reception, drying and storage of working clothes, bathrooms, etc.;
- Develop schemes and arrange temporary access roads for traffic to the place of work;
- arrange temporary storage sites for the reception of structures, construction parts and materials;
- prepare for the production of works of the machine, mechanisms and equipment provided for by the PPR, deliver them to the object, mounted and test at idle;
- to deliver a demanding equipment to the area of \u200b\u200bwork, devices for safe production of works, electrified, mechanized and hand tools;
- provide the construction site by fire inventory and means of alarm;
- ensure communication for operational dispatching management of work;
- draw up an act of readiness of the enterprise to the work of work;
- Get the technical supervision of the customer permission to start the production of works.
3.3. General requirements for work
3.3.1.
The maintenance of roads includes a complex of engineering and technical measures and work on systematic care for expensive, road structures and a disquisite strip, in order to prevent and maintain them in a proper manner throughout the year and the correction of minor deformations and damage to all structural elements, as well as the organization and provision traffic safety.
Performance of maintenance work in full and high quality slows down the process of deterioration of road operating indicators.
3.3.2.
The content task is to ensure the safety of the road and road facilities and maintaining their condition in accordance with the requirements allowed by the conditions for ensuring the continuous and safe movement 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.
The composition of the maintenance of road clothing includes:
- cleaning of road surfaces from garbage, dust and dirt, cleaning of foreign objects, elimination of sliding caused by bitumen;
- elimination of small deformations and damage (sealing chosel, drawdowns, etc.), correction of edges (borders) on all types of coatings, filling cracks on asphalt concrete and cement concrete coatings, restoration and filling of deformation seams in cement concrete coatings;
- repair of chips and bugs of cement concrete coatings, replacement, lifting and alignment of individual plates;
- protection of cement concrete coatings from superficial destruction;
- a device of protective layers from emulsion-mineral mixtures in the peeling sites and painting asphalt concrete and cement concrete coatings;
- elimination with a depth of 30 mm by laying two layers of an emulsion-mineral mixture or surface treatment according to row strips with a width of up to 0.8 m;
- partial milling or cutting of the ridges of the imposition and irregularities by filling with a roll of black rubble or asphalt concrete and a protective layer device from an emulsion-mineral mixture to the entire width of the coating;
- Stop and preventing the development of cracks and a grid of cracks with an insulating layer of fine-grained surface treatment with local maps;
- restoration of the worn upper layers of asphalt concrete coatings and styling them again on separate small lengths (up to 20 m) of roads of the road;
- correction of the profile of rubbed and gravel coatings with the addition of rubble or gravel;
- profiling of ground and soil improved roads, recovery of profile and improving their carriage part of rubble, gravel, slag and other materials with a flow rate of up to 100 m per 1 kilometer;
- Dusting roads;
- Caring for roads with bunched and weak soils.
3.3.5.
IN spring period (Before the intensive melting), snow and ice should be removed from the roadway and the rook. After drying, the coating is carefully cleaned from dirt, dust, antifungal materials using various means of mechanization of cleaning operations.
In the spring, during the maximum moisturizing of the earth canvas, special attention is paid to the protection of coating from destruction. Road service based on passport data or by the results of the assessment should determine the greatest loads that can be missed by serviced roads.
At weakened areas, especially on roads with lightweight types of coatings (overvoltling of the earth canvas, puchins), measures are performed to increase the bearing capacity of the road construction by laying shields, twigs, boards, draining soil with their subsequent cleaning after restoring the strength of the road construction. If it is impossible to perform their implementation or insufficient efficiency, limit the movement of heavy loading vehicles, reduce the speed or completely closed the passage, translating it into specially prepared detours. When organizing these activities, be guided by special documents for restriction or closing of road traffic.
In the spring of the onset of warm and sustainable weather, it is processed to eliminate small damage in the form of elevation, cracks, individual waves, bugs and influx, etc.
3.3.6.
IN summer period Perform work on cleaning the carriageway of the road from dust and dirt, especially in adverse weather conditions. Cleaning is carried out with mechanical brushes, watering and washing and sweeper-cleaning machines.
3.3.7.
Repair meal - repair work, eliminating defects in the form of chosel, separate waves, influx, bugro, etc.
The task of displacement is to restore continuity, evenness, strength, coupling qualities and waterproof coverage and ensuring the regulatory service life of repaired areas.
As a rule, all the works on the holes are performed early in the spring, as soon as weather conditions and the condition of the coating are allowed. In the summer and in the fall, the sealing of chosel and yams are made immediately after their appearance.
According to the type of repair material used, two groups of methods of displacement are distinguished: cold and hot.
Hot methods Based on the use of hot asphalt concrete mixtures as a repair material: fine-grained, coarse-grained and sandy mixes, cast asphalt concrete, etc. Hot methods of patchwork allow you to provide higher quality and long service life of the repaired coating.
Measuring repair using a hot way is used in the repair of roads with asphalt concrete coating and is performed using two components - bitumen emulsion and hot asphalt mixture. The composition and properties of the asphalt mixture used for the repair must be similar to the one of which the coating is made.
Bituminous road emulsion - This is a homogeneous low-brown liquid of dark brown color, which is obtained by fine grinding bitumen in an aqueous solution of the surfactant (emulsifier). Due to low viscosity, this material is used as a film-forming or binder, which ensures the most favorable conditions for the processing of road surfaces. The indisputable advantages of the road bitumen emulsion include: environmental friendliness, safety and durability. It is actively used both on concrete and on asphalt and crushed stone coatings.
Hot asphalt concrete mixtures high-profile and dense types A and B - It is rationally selected gravel mixtures, sand (natural or from crushing docks), mineral powder and road bitumen (with or without additives), mixed in heated state, laid thick, exceeding the maximum rubble size of at least 2-2.5 times.
Hot asphalt concrete mixes are used, as a rule, mainly when repairing the coatings of roads I-II categories.
Works can be performed at air temperature not lower than + 10 ° C with an outdown base and dry coating. When using a heater of the repaired coating, it is allowed to repair at an air temperature not lower than + 5 ° C.
3.4. Preparatory work
3.4.1.
Prior to the production of work on the patch repair of asphalt concrete coatings, the TTK preparatory work must be made by the hot asphalt concrete mixture, including:
- with a representative of the technical supervision of the Customer, an inspection of the road was inspected to assess the condition and determination of species, volumes and technology of the work of the work necessary for the full and high-quality elimination of identified defects and damage to road clothing;
- the results of regular inspections of the section of the road and structures, made by representatives of the General Contractor (Unitary Road-Operational Enterprise) and the daily inspections of the auto road, elements of the arrangement and structures are studied;
- analyzed the identified defects and inconsistencies in the level of content and regulatory requirements, the volume of repair work;
- on the basis of the analysis and technical inspection of the detected inconsistencies, to make a defective statement, which serves as a basis for determining and planning work, it is evaluating the technical condition of the part of the road, structures;
- on the basis of a defective statement to develop and approve the necessary calculations of labor, industrial and material resources, estimates, estimates and drawings in the technical customer;
- Repeated with a representative of the technical supervision of the Customer to inspect the section of the road to clarify the design solutions and identify additional works, missed or unaccounted by project and estimates;
- Road signs and fences of the work of work under the scheme are placed.
3.4.2.
P an increased decision of the eternal problem
G. the lavetled difference of the current repair of asphalt from the capital is the possibility of its implementation without the complete replacement of the road surface, that is, at times faster and cheaper, but with a good practical result (with the restoration of up to 85% of the functional characteristics of the new road cover). At the same time, I would like to emphasize that the current repair is not a forced semi-meter - this is a kind of full road repair.
Depending on the objectives of them pursued, the maintenance of the asphalt is made to divide the three main groups:
- fractured (sealing cracks of installed thicknesses and depths);
- meal (elimination of large picking);
- carpets (the local update of the asphalt canvas by smoothing the so-called "wear carpets").
Measuring repairs are the most common among all of the above. It is used everywhere - and on city streets, and on the roads of local importance, and on country highways. The positive effect of it is high, regardless of the overall state of the repair pavement. Unless, of course, the repair was performed in accordance with the installed technology.
Meal repair, how professionals see him
The technological sequence of the production of stalk repair is quite simple:
- purification of waste from garbage, dust, soil, asphalt drossy (cleaning is performed by compressor method - "purge");
- heating edges potholes (needed to improve adhesion);
- filling the asphalt mixture (with a preliminary application of a bitumen emulsion);
- pressing the surface (contributes to the alignment and sealing of the asphalt mixture).
The experience of operating asphalt concrete coatings on urban streets and roads shows that their service life to overhaul is approximately 8-10 years. On the asphalt concrete coatings, all sorts of cracks, shifts and gates appear (especially at the stopping points of public transport), breaks and drawdowns (near the hatches of the wells, tram track rails, in the places of former opening of road clothes, etc.). Under the influence of vehicles, the process of wear (abrasion) of the surface layer of the asphalt concrete coating is manifested and, over time, road clothing loses the necessary bearing capacity.
In accordance with the classification, the repair of road clothing and coatings is divided into three types: the current, medium and capital. The current repairs include work on emergency correction of small damage in order to prevent further coverage destruction. Average repair of execution in order to restore the bearing capacity of road clothing and increasing road transport and operational indicators. In case of major repairs, work is performed on the complete or partial replacement of the structural layers of the asphalt concrete coating.
Types of deformations of asphalt concrete coatings, the causes of their occurrence and solutions are shown in Table. 86.
The composition of the ongoing repair of asphalt concrete coatings includes sealing cracks, repair of awards and elevation, restoration of road clothing after leaving, elimination of waveforming, influx, stakes, shifts.
Cracks in asphalt concrete coatings usually occur during periods of sharp decrease in temperature (with strong and fast frost). Depending on the width of the cracks, it is divided into small - up to 0.5 cm, medium - up to 2 cm and large - up to 3 cm. Cracks, raging, lead to the destruction of the road coating. Therefore, their seal should be considered an important preventive event. For fillings and sealing cracks, the following materials are recommended: Liquefied or liquid brands of SG-70/130, SG-130/200, MG-70/130, MG-130/200, followed by processing the surface of the seam with black extensions of the fraction 3-7 mm; Revinobitume binder (RBV) consisting of bitumen, rubber crumb, softener; Mastics consisting of renumber binders and solid fillers.
Revurbitume binders and mastic are prepared in special stationary installations.
Small cracks (0.5 cm) it is advisable to fill in a renumber binding or dischargeable bitumen, followed by a mineral material; Cracks width more than 0.5 cm, as a rule, are filled with renumber binders or mastic. Liquid and liquefied bitumens are obtained by adding kerosene to viscous heated bitumes before use to 80-100 ° C.
The cracking material must have elasticity, heat resistance, good clutch (adhesion) with asphalt concrete and stone materials, high fluidity, when pouring should be easily poured out of the worker's working body and completely fill the crack. Elasticity is achieved by introducing synthetic rubber or rubber crumb into mastic, and heat resistance - the introduction of solid fillers: mineral powder, asbestos chip or joint use of viscous road and construction bitumen. The most common made of synthetic mastic preparation materials is the elastic material polyisobutylene, which has good adhesive properties and high resistance to chemical reagents.
In urban road construction for sealing cracks in asphalt concrete coatings, various compositions of mastic are used. In tab. 87 shows the mastic compositions selected for their use in II, III and IV climatic zones.
The selection of the composition of the mastic is to obtain such a mixture of binder and fillers, which would have a given softening temperature and sufficiently high fluidity at operating temperature. The softening temperature of mastic for the II road-climatic zone must be within 60 ° C, and III and IV - from 60 to 75 ° C.
Cracks close in dry weather at air temperature at least + 5 ° C. It is best to get the cracks in the first half of the road repair work, when the cracks are most disclosed. Before sealing, they need to thoroughly clean dust and dirt and dry. The dirt lay down in medium and large cracks is pre-breaking with metal hooks, and then clean them from dust with flat metal brushes. For final purification from dust and dirt, cracks are purged from the hose of a jet of compressed air. After cleaning and drying, they are poured with waterproofing materials.
For cutting and cleaning cracks at the current repair of asphalt concrete coatings, the DE-10 machine is used. The machine is a mobile three-wheeled trolley, manually controlled, on which the compressor is installed, fuel tank and thermal tooth, which is a working organ of the machine in the form of a reactive burner. Fuel from the tank is served under pressure air entering the tank and to the tool. When cutting the edges of cracks to a depth of up to 40 mm, the machine performance is 100-110 m / h, when cleaning the cracks of the same depth, the performance reaches 600 m / h.
More than 3 cm width cracks can be chopped with a cold and hot asphalt concrete mixture. When the cold mixture of cracks is filled with a discharged bitumen and stone extensions with such a calculation so that after sealing them to the surface of the coating, 8-10 mm remained. On top of the existers lay a layer of cold asphalt concrete, which is sealing with motor rollers with a mass of 1.5-3 tons. When the hot mixture of cracks are smeared with a dischargeable bitumen, and then filled with a hot asphalt concrete mixture, which is sealing with motor rollers weighing 5-6 tons.
In the presence on the asphalt concrete coating, the solid shallow mesh of cracks caused by the destruction of the coating due to the inconsistency of the properties of the asphalt concrete, the required or weak base, the sealing of the crack is not produced, and the damaged coating is removed completely and restored after repairing the base.
Repair of individual awards and choseli in the asphalt concrete coating must be produced by asphalt concrete mixtures of about the same compositions from which the coating is built. Materials should be taken out in the amount required for the repair of this section of the road. Unused materials and waste should be exported in a timely manner.
The stump of the repaired area should be made by a straight contour. Destroyed places from each other at a distance of 0.5 m are repaired by a shared map. The outline of cutting out on the rail. If only the top layer of coating is damaged with a thickness of no more than 1.5 cm, then the repair leads without cutting down the lower layer. If the coating is damaged to a greater depth, the coating is cut down to the base. Before laying an asphalt concrete mixture, the repaired place is thoroughly cleaned and processed (lubricated) along the edges and the base of hot or discharged bitumen. Lubrication provides the necessary adhesion of a newly laid coating with an old base.
The temperature of the mixed mixture should be from 140 to 160 ° C. The mixture must be homogeneous, without lumps, it should be sealing by motor rollers. After sealing the place of the adjoining of the old and re-laid asphalt concrete to ensure sufficiently dense pairing is treated with hot iron or thermal radiation burners.
When repairing small damage in coatings from a cold asphalt concrete at a depth of chosen more than 4 cm, they are close in two layers. A hot fine-grained or medium-trimmed mixture is placed in the lower layer, taking into account that during its sealing it remains at least 2 cm for laying the upper layer from the cold mixture.
At the current repair of asphalt concrete coatings, along with cutting off the destroyed layer, a large propagation was obtained by the method of removing the deformed asphalt concrete with the help of ac-foologenes. Asphalt-beaters are advisable to apply when fixing shifts, waves, spills, killers at public transport stops. The asphalt-heater of DE-2 (D-717), shown in Fig. 119, mounted on the chassis of the car UAZ-451DM, in the closed body of which accommodates the following equipment: a gas-plane unit, which includes cylinders with liquefied gas, low pressure reducer, pipelines and sleeves; Infrared radiation burner block with lifting mechanism; Hydro and electrical equipment. In addition to the described asphaltological heater manufactured by the industry, individual road-based operational organizations are manufactured for their needs heat radiation heater mounted on car chassis (RA-10, RA-20, AR-53, etc.).
Along with the asphalt-shirts at the current repairs, the Repair of DE-5 (D-731) is used, which heating asphalt coatings are carried out using infrared emitters. The repair is mounted on the GAZ-5EA car chassis, in the body of which placed the thermos bunker for the asphalt concrete mixture, containers for mineral powder and bitumen emulsion, portable blocks with infrared burners, mobile infrared heater, distribution trolley, electric gates, electromotive C-349, electrotrovkovka C-690, Hand tools (shovels, smooth, brushes, etc.) and enclosing shields and signs.
As a result of the use of machines equipped with sources of infrared radiation, more advanced methods for repairing asphalt concrete coatings were developed, in which the heat heating occurs without burning in the bitumen, which allows the use of the asphalt concrete-processed method for the device of the lower or leveling layer with the overlapping of its fresh mixture. Currently, tests have passed and the machine for the repair of asphalt concrete coatings with electrical quartz emitters is recommended.
After repair or laying underground communications, destroyed road clothing is restored after a thorough sealing of teeth and complete stabilization of the precipitation of the earth canvas. If it is not possible to achieve the necessary density of the base and earth canvas and the appeal is possible, it is possible to arrange a temporary coating using coarse-grained black chicken mixtures or a cold asphalt concrete with periodic, as precipitation, profile correction by the same materials. After attenuation of the sediment, road clothing in the disinfect places are arranged from the same materials from which the repaired road is erected.
The production of work on the current repair of sidewalks with asphalt concrete coatings is carried out by the same methods and rules that are used when performing the current repair of the carriageway of streets and roads with asphalt concrete coating. The main difference is that when repairing sidewalks, special sidewalk machines of small dimensions and less productivity are used: paving layouts, paving rollers, cracks of cracks, etc.
With the loss of asphalt concrete coating of the necessary roughness, the appearance of a large number of cracks, as well as a significant wear of the surface layer, plan an average coating repair. The coating roughness is restored to surface treatment. Surface treatment improves the appearance of the coating that has been substantially repaired, creates an independent deposit layer, eliminates slipness and gives the coating a roughness that increases the safety of traffic movement.
For surface treatment, crushed stone with a strength of at least 600 kgf / cm2 (60 MPa) fractions 5-10, 10-15, 15-20 and 20-25 mm are used. Crushed stone is pre-treated in stationary asphalt mixing plants or mobile concrete mixers bitumen or bitumen emulsion. The flow of black rubble of various fractions and a binder can be taken in accordance with the data table. 88.
With surface treatment, it is necessary to prepare a coating to bottling, pour the binder and scatter the stone material, compact the material with rollers and carpeted coating before making the rug. To prepare a coating to surface processing, you need to perform the necessary repair and plant cracks, as well as eliminate the surfaces on the coating. The last operation is particularly important, since the existing irregularities cannot be eliminated by surface treatment.
The binder is spilled by autogudaronators and are evenly distributed over the coating. With single-layer processing, after the filling of the binder immediately scatter out the resulting crushed stone. With double processing, the stone material of larger fractions first scatter and seal it, and then the bitumen is repeated again and the stone material is scattered with less large fractions. For better contact of the stone material with a binding seal, the resulting crushed rollers should immediately after its placer, while the spilled bitumen has the greatest temperature. The seal is conducted from the edges to the middle; The number of rink passes on one trace 4-5. To avoid crushing the roller rollers, it is necessary to use rollers on pneumatic tires.
The outdoor temperature during surface treatment should not be lower than + 15-20 ° C, and the surface of the coating should not be wet to ensure good adhesion of the binder with stone material. Finally, the rug is formed under the influence of moving transport, so some time after the start of the movement should be monitored.
Along with the surface treatment, the wear layer is restored by increasing to the existing coating of a new layer of asphalt concrete. As with surface treatment, the wear layer is suitable only after sealing cracks, drawdowns, chosen and other coating deformations. At the same time, to improve the safety of automotive movement, the increasing layer should have a roughness that ensures a reliable clutch of the vehicle wheels with the surface of the road. The coating device with an increased clutch coefficient should be started at the beginning of the road repair work at the steady air temperature not lower than 15 ° C. In urban conditions, three methods of coating devices with an increased coefficient of clutch are used.
In the first method, specially selected mixtures with an elevated content of rubble are placed in the upper coating layer. To obtain a rough surface, it is necessary to have 60% rubble in a mixture. When the rough surface device, the technology of work remains the same as the device of conventional asphalt concrete coatings. The layer tool in this case is carried out immediately with heavy rollers. With insufficient rigging, such a coating becomes short-lived.
According to the second method, a hot black crushed stone is scattered on the inspected top layer of the asphalt concrete cover and ripen it. The asphalt concrete mixture of the usual composition is placed asphalt paver and slowly rolling with light rollers, then scatter and smash the hot black crushed stone of the fractions 15-20 or 20-25 mm and lead the water rollers. The black crushed stone of the 15-20 mm fraction is scattered in the amount of 15-20 kg / m2, and the fractions are 20-25 mm - 20-25 kg / m2. By the beginning of the placer, the temperature of the black crushed stone must be 130-150 ° C, and the temperature in front of the rollers - not lower than 100 ° C. To the place of laying the mixture should be submitted continuously; Every 5-6 cars with a mixture need to serve a car with a hot black rubble.
In the third method, the rough surface is created in the insertion of the materials (fraction less than 100 mm), treated with bitumen, with a final compaction of the asphalt concrete mixture in such a technological sequence: put the top layer of the coating of a fine-grained plastic mixture with a rubble content of 30%; Pre-seal a mixture with light rinks (2-6 passes on one trace); The material treated with bitumen is distributed over the surface of the coating with a solid smooth layer using a lightweight asphalt paver or manually; Seal with rollers on pneumatic tires or heavy rollers. The temperature of the material distributed must be 120-140 ° C, and the coating temperature is -80-100 ° C. The flow rate of materials treated with bitumen, fraction 5-10 mm is 10-13 kg / m2, fractions 3-8 mm - 8-12 kg / m2 and fractions 2-5 mm - 8-10 kg / m2. Movement of vehicles on covering with tweed materials treated with bitumen, can be opened the day after the end of work.
In case of major repairs of asphalt concrete coatings, the basis for the installation of the asphalt concrete, laying the mixture, the sealing of the asphalt concrete and the surface finish is carried out. The preparation of the foundation is to build wells by reinforced concrete segments before the design mark, in cleaning the base from dust and dirt, drying and lubrication of its bitumen emulsion. Purification of the base lead mechanical brushes, sweeping machines. If necessary, the base surface is washed with irisomatic machines (PM-130, PM-10) or cleaned with compressed air supplied from the compressor receiver through special nozzles.
The laying of the asphalt concrete mixture on the wet surface is not allowed, since it does not ensure the necessary coating with the base. Wet bases are dried with asphalt or hot sand with hot sand, heated to 200-250 ° C. Before laying asphalt concrete, the base is covered with a bitumen emulsion or a dischargeable bitumen with mechanical sprayers mounted on an autoglyonator, as well as a special brush mounted on a water-wary machine.
The bitumen emulsion is applied with a thin uniform layer 2-3 hours before laying asphalt concrete mixture. The consumption of a binding per 1 m2 coating is 200-300. The approximate composition of the emulsion: bitumen 55-58%, water 41-43%, sulphite-yeast brazing up to 4%. The laying of the asphalt concrete mixture can be started only after the bitumen film will completely dry and grab well with the base.
To obtain the required thickness of the coating after bottular emulsion, you set control beacons or put the top of the coating on the curb stone. The top of the lighthouse or mark on the border stone must correspond to the top of the coating after the seal. All protruding parts of underground structures are lubricated by bitumen. When the two-layer coating device, the bottom layer is placed on such an area, which can be covered in the next shift by the upper layer. This achieves the best clutch of the coating layers and additional cleaning work are significantly reduced.
The asphalt concrete mixture is placed at a temperature not less than 130 ° with asphalt pavers of various types. Asphalt pavers allow you to smoothly change the layer thickness (from 3 to 15 cm) and ensure the laying of the mixture in compliance with the specified transverse profile. To increase the stacked strip, the stacker includes a screw of a screw, a frambling timber and a smoothing plate. 30 cm long-term broadcasters can be installed from one or both sides.
The number of strips of the laid asphalt concrete mixture in the width of the carriage part are taken taking into account the length of the traaming timber of the asphalt paver and the need to overlap each band by an average of 5 cm. To ensure the monolith of two adjacent bands, the mixture temperature at a previously laid lane should not be lower than 80 ° C. To get good The longitudinal spike stripes of asphalt concrete strip length stacked in one side of the asphalt paver should be taken depending on the air temperature.
In the presence of borders, the asphalt paveter moves at a distance of 10 cm from them, and the formed gap and other places are not available for mechanical stacking (at wells, on cool turns), close manually simultaneously with the operation of the asphalt paver. The thickness of the layer is taken, taking into account the coefficient of seal 1.15-1,20.
Before laying each next band, you need to warm up the spike previously laid. To do this, the edge of the compacted strip is covered with a hot mixture roller on a width of 15-20 cm, which is removed in front of the rain. Spicy spikes can also be laughing asphalt or autogogene burner. The asphalt concrete mixture is first sealing with light rinks, and after 4-6 passes on one trace - rollers on pneumatic, or vibrational 10-13 passes on one trace. The seal should be conducted at a mixture temperature of 100-125 ° C. It must be completed at a temperature not lower than 75 ° C. Retail of the lower layer at the air temperature below 10 ° C is allowed to carry out heavy rollers.
The top layer is laid along the bottom only after its cooling to 50 ° C at an air temperature of 10 ° C or up to 20-30 ° C at an air temperature above 10 ° C. The process of the upper layer device is the same as the lower. To compact the upper coating layer in mechanical laying, the mixture requires 5-7 passengers of the lungs and 20-25 passes of heavy rinks along one trace.
13.4. Measuring repair of coatings from asphalt concrete and bitumenineral materials. Main methods of patch and technological operations
The task of displacement is to restore continuity, evenness, strength, coupling qualities and waterproof coverage and ensuring the regulatory service life of repaired areas. In case of melling, various methods, materials, machinery and equipment are used. The choice of one or another method depends on the size, depth and number of elevation and other coating defects, type of coating and materials of its layers, available resources, weather conditions, requirements for the duration of repair work, etc.
The traditional method provides for stubbling edges of the edges of the rectangular outlines, cleaning it from asphalt scrap and dirt, brewing the bottom and edges, filling it with repair material and seal. To give a selection of rectangular outlines, small cold milling machines are used, disk saws, perforators.
Asphalt concrete mixtures are preferably used as a repair material, which requires compaction, and from the means of mechanization - small rollers and vibration machines.
When carrying out work in conditions of increased moisturizing, sequested air (hot or cold), as well as the use of burners of infrared radiation, are drunk. If the coating is repaired by small maps (up to 25 m 2), heated the entire area; When repairing large cards - around the perimeter of the plot.
After preparation, the injection is fill in the repair material taking into account the reserve for the seal. At depth, the chosable to 5 cm is placed in one layer, more than 5 cm - in two layers. The seal is made from edges to the middle of repaired areas. When suppressing, the chosable is deeper than 5 cm into the bottom layer lay a coarse mixture and compact. This method allows you to obtain high quality of repair, but requires a significant amount of operations. It is used in the repair of all types of coatings from asphalt concrete and bitumenineral materials.
Small potholes with a depth of 1.5-2 cm on an area of \u200b\u200b1-2 m 2 and are more repaired by the method of surface treatments using rubble small fractions.
The method of repairing the damaged coating and the reuse of its material is based on the use of special equipment for heating the coating - asphaltorogene. The method allows to obtain high quality repairs, ensures the savings of the material, simplifies the technology of work production, but has significant limitations on weather conditions (wind and air temperature). It is used in the repair of all types of coatings from asphalt concrete and bitumenineral mixtures.
Method of repairing the filling of chosel, holes and sawmills without cutting or heating the old coating is to fill these deformations and destruction by a cold polymemraft-concrete mixture, a cold asphalt concrete, a wet organineral mixture, and the like. The method is characterized by simplicity of execution, it allows you to perform work in cold weather with a wet and wet coverage, but does not provide high quality and durability of the repaired coating. It is used when repairing coatings on roads with low motion intensity or as a temporary, emergency measure on roads with high traffic intensity.
The type of repair material used is distinguished by two groups of displacement methods: cold and hot.
Cold methodsbased on the use of cold bitumenineral mixtures as a repair material, wet organineral mixtures (WOMS) or cold asphalt concrete. It is used mainly to repair coatings from black rubble and cold asphalt concrete on the roads of low categories, as well as if necessary, urgent or temporary sealing, elevated in earlier terms on the roads of high categories.
Working on the holes in this way is beginning in spring, as a rule, at air temperature not lower than + 10 ° C. If necessary, cold mixtures can be used for naval repairs and at a lower temperature (from + 5 ° C to -5 ° C). In this case, before laying a cold black crusp, or a cold asphalt concrete mixture is heated to a temperature of 50-70 ° C, the bottom and the walls are heated and the walls are heated until the bitumen appears on their surface. In the absence of burners, the bottom surface and walls are deceived by bitumen with a viscosity of 130/200 or 200/300, heated to a temperature of 140-150 ° C. After that, the repair material is placed and compacted.
The formation of the coating at the repair point is cold due to the movement of transport for 20-40 days and depends on the properties of a liquid bitumen or bitumen emulsion, the form of mineral powder, weather conditions, intensity and movement composition.
Cold asphalt concrete layers for naval repairs are prepared using a liquid media regulatory or slow-driving bitumen with a viscosity of 70/130, according to the same technology as the hot asphalt mixtures, at a heating temperature of the bitumen 80-90 ° C and the temperature of the mixture at the outlet of the mixer 90-120 ° С. The mixtures can be stored in stacks up to 2 m high. In summer, they can be kept in open areas, in the autumn-winter period - in closed warehouses or under a canopy.
Repair work can be performed at a lower air temperature, harvest in advance repair material. The cost of work on this technology is lower than with a hot way. The main disadvantage consists in relatively small deadlines of the renovated coating on the roads with the movement of heavy trucks and buses.
Hot methodsbased on the use of hot asphalt concrete mixes as a repair material: fine-grained, coarse-grained and sandy mixes, cast asphalt concrete, etc. The composition and properties of the asphalt mixture used for the repair of the asphalt concrete mixture should be similar to the coating. The mixture is prepared according to ordinary cooking technology for hot asphalt concrete. Hot methods are used when repairing roads with asphalt concrete coating. Works can be performed at air temperature not lower than + 10 ° C with an outdown base and dry coating. When using a heater of the repaired coating, it is allowed to repair at an air temperature not lower than + 5 ° C. Hot methods of snack repair allow you to provide higher quality and long service life of the renovated coating.
As a rule, all the works on the holes are performed early in the spring, as soon as weather conditions and the condition of the coating are allowed. In the summer and in the fall, the sealing of chosel and yams are made immediately after their appearance. Technology and organization of work in various ways have their own characteristics. However, for all methods of displacement, there are general technological operations that are performed in a certain sequence. All these operations can be divided into preparatory, basic and final.
Preparatory work includes:
installation of fencing places of work of work, road signs and lighting device, if work is performed at night;
markup of repair sites (cards);
cutting, breaking or milling of damaged areas of the coating and cleaning of the removed material;
cleaning choseli from remnants of material, dust and dirt;
drying bottom and walls are potholes, if the repair is produced by a hot way with a wet coverage;
processing (progressing) of the bottom and walls are injected with bitumen emulsion or bitumen.
Marking of places of repair (repair cards) is produced using a strained cord or chalk using a rail. The repair point is delineated by straight lines parallel and perpendicular to the axis of the road, giving the contour the correct shape and capturing the intact coating on the width of 3-5 cm. Several elevations that are at a distance of up to 0.5 m one from the other, are combined into a common card.
Cutting, fault or milling of the coating within the marked card is produced on the thickness of the destroyed coating layer, but not less than 4 cm throughout the repair area. At the same time, if the bottom layer of the coating affected the bottom layer in depth, the thickness of the lower layer with the destroyed structure is removed.
It is very important to remove and remove the entire destroyed and weakened layer of asphalt concrete, capturing the bandwidth of at least 3-5 cm from a durable, non-destructive asphalt concrete throughout the marked contour. It is impossible to leave these edges of these edges potholes, since the monolith of asphalt concrete is weakened here at the expense of the formation of microcracks, loosening and painting individual churches from the walls potholes (Fig. 13.10, a). In the pothole, water is assembled, which, under the dynamic effect of the wheels, penetrates the interlayer space and weakens the clutch of the upper layer of asphalt concrete with the bottom. Therefore, if you leave the weakened edges potholes, then after laying the repair material after a while, weakened edges can be destroyed, the newly laid material will lose touch with a solid old material and the development of potholes will begin.
Fig. 13.10. Cutting potholes before laying repair material: A - cutting of weakened places; B- cutting edges potholes after milling; 1 - weakened wall potholes; 2 - the detached part of the coating; 3 - the destroyed part of the bottom potholes; 4 - chopped or beveled wall potholes
The walls of the edges are potholes after cutting should be vertical over the entire contour. Cutting and the focusing of the coating can be carried out with the help of a jackhaft pneumatic hammer or scrap, concrete colon, cutter of seams and a ripper or with the help of a road cutter.
When using the road cutter for cutting, the rounded front and rear walls are formed, which should be trimmed with a disk saw or a jackhammer. Otherwise, the upper part of the stacked layer of repair material in places of pairing with the old material will be very thin and quickly collapsed (Fig. 13.10, b).
The degraded material of the old coating is removed from the potholes manually, and when using the road cutter, the material (granules) of the loading conveyor is supplied to the dump truck and exported. Cleaning the card is carried out using a shovel, compressed air, and with a large map area - using sweeping machines. Drying the bottom and walls of the card are made by the need to purge hot or cold air.
The processing of the binders (brewing) of the bottom and walls, the elevation is produced in the case of styling as a repair material of hot asphalt concrete mixtures. This is necessary in order to ensure the best sewing of the material of the old asphalt concrete to the new one.
The bottom and the walls of the purified card are treated with a liquid medium-risk 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 a bitumen emulsion with a flow rate of 0.8 l / m 2. In the absence of means of mechanization, bitumen is heated in mobile bitumen boilers and are distributed based on the base with watering can.
Filling potholes by repair material can be performed only after the fulfillment of all preparatory work. The laying technology and the sequence of operations depends on the method and volumes of work, as well as on the type of repair material. With small volumes of work and the absence of means of mechanization, the laying of the repair material can be done manually.
The temperature of the hot asphalt concrete mixture delivered to the placement location should be close to the preparation temperature, but not lower than 110-120 ° C. Most appropriately stacked the mixture at such a temperature when it is easily processed, and in the process of laying, waves and deformations are not formed when the roller pass. Depending on the type of mixture and its composition, such a temperature is considered: for a single mixture - 140-160 ° C; For the average mixture - 120-140 ° C; For a model-free mixture - 100-130 ° C.
The laying of the mixture in the card is made in one layer at a cutting depression up to 50 mm and two layers at a depth of more than 50 mm. At the same time, a coarse mixture with a rubble size of up to 40 mm can be laid into the lower layer, and only a fine-grained mixture with a fraction of up to 20 mm in the upper layer.
The thickness of layer layer in a loose body should be greater than the thickness of the layer in the dense body, taking into account the reserve coefficient for the seal, which is adopted: for hot asphalt concrete mixtures of 1.25-1.30; for cold asphalt concrete mixtures 1.5-1.6; For wet organic mineral mixtures of 1.7-1.8, for rubble and gravel materials treated with binders, 1.3-1.4.
When laying the repair material with a mechanized manner, the mixture is supplied from the thermos bunker through a rotary tray or a large-diameter flexible sleeve directly in the pothole and evenly recalling throughout the area. Laying asphalt concrete mixtures when chosening a map of 10-20 m 2 can be made by asphalt paver. At the same time, the mixture is stacked on the entire width of the map in one pass to avoid an additional longitudinal seam of pairing laying bands. The sealing of the asphalt concrete mixture laid into the bottom layer of the coating is made by pneumatic bands, electric machines or manual vibration rods in the direction from the edges to the middle.
The asphalt concrete mixture laid into the upper layer, as well as a mixture laid in one layer at a depth of 12 mM, seal a self-propelled vibration rink (first two passages along the trail without vibration, and then two passages along the vibration track) or static smooth light-type rollers Weighing 6-8 tons up to 6 passes on one trace, and then heavy rollers with smooth rollers weighing 10-18 tons to 15-18 passes one trail.
The sealing coefficient must have a value of not lower than 0.98 for sandy and unauthelastic asphalt mixtures and 0.99 for medium and single mixtures.
The sealing of hot asphalt concrete mixtures begin at the highest possible temperature at which deformations are not formed during the headcase. The seal should ensure not only the required density, but also the flattering layer, as well as the location in one level of the repaired coating with the old one. For a better conjugation of a new coating with the old and the formation of a single monolithic layer when laying hot mixes of the joint over the entire contour of the deforestation, using a line of burners or an electrical warmer. Speakers over the surface of the coating of the sealing junctions, the elevation is eliminated by milling or grinding machines. Final work is the cleaning of the remaining waste from repair with the loading of them in the dump trucks and the removal of fences and road signs, restoring the lines of markup in the zone of stitching repairs.
The quality of repair and service life of the repaired coating depend primarily on compliance with the requirements for the quality of the implementation of all technological operations (Fig. 13.11).
Fig. 13.11. The sequence of the main operations of the patch repair: and is correct; B- incorrectly; 1 - pothole before repair; 2 - cutting or cutting, cleaning and processing of binders (progress); 3 - filling with repair material; 4 - seal; 5 - view of renovated potholes
The most important are the following requirements:
repair must be performed at an air temperature not lower than that are permissible for this repair material on a dry and clean coating;
under the cutting of the old coating, a weakened material from all zones of potholes can be removed, where there are cracks, bugs and chipping; Repair card must be cleaned and sucked;
molds of repair card must be correct, walls with sheer, and bottom smooth; The entire surface of the potholes must be processed by binders;
the repair material must be laid at an optimal temperature for this type of mixture; The thickness of the layer must be more depth of potholes, taking into account the reserve on the seal coefficient;
the repair material must be thoroughly aligned and closed to the surface of the coating;
the formation of a new material layer is not allowed on the old coating at the edge of the card to avoid jolts at the car where the car and the rapid destruction of the renovated area.
The result of a properly performed repair is the height of the laid layer after the seal, exactly equal depth of the potholes without irregularities; Proper geometric shapes and imperceptible seams, optimal sealing of laid material and its good connection with an old coating material, a long service life of the repaired coating. The result of incorrectly accomplished repair may be irregularly compacted when its surface is higher or below the surface of the coating, arbitrary shapes of the map in terms of, insufficient seal and poor compound of repair material with the material of the old coating, the presence of protrusions and spills on the edges of the card, etc. Under the action of transport and climatic factors, the plots of such repairs are rapidly destroyed.
Meal repair of black crushed stone coatings or gravel. When repairing such coatings, simpler materials and methods of repair can be used, which make it possible to reduce the cost of maintaining roads with blackstone and black-breeding coatings. Most often, these methods are based on the use of cold bitumenineral mixtures or materials treated with bitumen emulsion as a repair material. One such materials is a mixture of an organic binder (liquid bitumen or emulsion) with a wet mineral material (rubble, sand or gravel-sandy mixture), stacked cold. As an activator, when using liquid bitumen or humming, cement or lime is used.
For example, for the repair of the depth of a depth of 5 cm, the repair mixture is used in the composition: 5-20 mm crushed stone - 25%; Sand - 68%; Mineral powder - 5%; Cement (lime) - 2%; liquid bitumen - over a mass of 5%; Water is about 4%.
The mixture is prepared in compulsory mixers in such a sequence:
mineral materials for natural humidity (crushed stone, sand, mineral powder, activator) are loaded into the stirrer; stirred;
add a calculated amount of water and stirred;
an organic binder is introduced, heated to a temperature of 60 ° C, and are finally stirred.
The amount of water injected is adjusted depending on its own humidity of mineral materials.
In the manufacture of a mixture, mineral materials are not heated and do not succumb, which significantly simplifies the cooking technology and reduces the value of the material. The mixture can be harvested in the future.
Before laying the mixture, the bottom and walls are not diagnosed with bitumen or emulsion, but wetted or washed with water. The mixed mixture is compacted and opened. The final formation of the layer occurs under traffic.
Measuring repairs using wet bitumenineral mixtures can be made at a positive temperature not higher than + 30 ° C and at a negative temperature not lower than -10 ° C in dry and raw weather.
Measuring repair of blackstone coatings by impregnation. As a repair material, crushed stone, previously treated in a stirrer with a hot viscous bitumen in an amount of 1.5-2% of the mass of rubble.
After the circuit marking the edges, the edges are chopped, boil the old coatings and remove the loose material, the bottom and walls are treated with a hot bitumen with a flow rate of 0.6 l / m 2. Then the black crusp stone of the fraction of 15-30 mm is placed and seal with a manual tamper or a vibratory bar; spill bitumen with a flow rate of 4 l / m 2; Put the second layer of black rubble fractions of 10-20 mm and compact it; Processing rubble bitumen with a flow rate of 2 l / m 2; Scattered stone explosion of fractions 0-10 mm and seal a pneumatic vibration rink. By the same technology, it is possible to repair the impregnation method and using a crushed stone that is not processed by bitumen. This increases the consumption of bitumen: at the first break - 5 L / m 2, with a second - 3 l / m 2. The distributed bitumen impresses the layers of rubble to the entire depth, as a result of which a single monolithic layer is formed. This is the essence of the impregnation method. For impregnation, viscous bitumens 130/200 and 200/300 are used at a temperature of 140-160 ° C.
A simplified method of patching with impregnation of rubble bitumen emulsion or liquid bitumen is widely used in France to close the small elevation on roads with low and medium traffic intensity. Such potholes are called "chicken nest".
Repair technology consists of the following operations:
initially, potholes or pits fall asleep by hand with a large size of a large size - 10-14 or 14-25 mm;
then, as the fine crushed stone of fractions 4-6 or 6-10 mm is scattered to the complete restoration of the road profile;
spill binder: bitumen emulsion or bitumen in a ratio of 1:10, i.e. one part of the binding of the ten parts of the rubble by mass;
manually with the help of vibrating plates produce a seal.
The binding penetrates the crushed stone layer to the base, as a result of which the monolithic layer is formed. The final formation occurs under the action of moving cars.
In addition to direct impregnation for snack repair, the reverse impregnation method is used. In this case, the bottom of the prepared card is spilled by bitumen with a viscosity of 90/130 or 130/200, heated to a temperature of 180-200 ° C. The thickness of the bitumen layer should be equal to 1/5 of the depth of potholes. Immediately after the spill of the hot bitum, the mineral material falls asleep: crushed stone fractions 5-15; 10-15; 15-20 mm, row crushed stone or gravel-sand mixture with particle size up to 20 mm. Mineral material is spilled and seal the rubbing.
When the mineral material interacts with natural humidity, the hot bitumen occurs foaming and the material is impregnated with bitumen from the bottom up. If the foam did not rose to the surface of the material, it produces a repeated spill of the binder from the calculation of 0.5 l / m 2, fall asleep with a thin layer of rubble and compact.
At depth of potholes up to 6 cm, all its fillings are performed in one layer. At greater depth - filling is made by layers with a thickness of 5-6 cm. Works on the patch repair in this way can be performed at a negative air temperature. However, the service life of repaired areas is reduced to 1-2 years.
Measuring repair with the use of rubble, treated with bitumen emulsion, has a number of advantages: there is no need to warm up astringent for the preparation of the mixture; can be laid at a positive ambient temperature, i.e. Since the beginning of spring and to the end of autumn; the rapid decay of the cationic emulsion, which contributes to the formation of the repair layer; No stump edges, removal of material and brewing.
To perform work, a car-repair is used, which includes: a base car with a heat-insulated tank for an emulsion with a capacity of 1000 to 1500 liters; switchgear for emulsion (compressor, hose, nozzle); The bunkers of the rubble fractions from 2-4 to 14-20. The cationic emulsion used must be with a rapid decay, contain 65% bitumen and is in a warm state at a temperature of from 30 ° C to 60 ° C. The processed surface should be clean and dry.
The technology of repairs of deep holes is more than 50 mm of type "chicken nest" (French terminology) consists of the following operations: Laying the crushed stone layer of the fraction 14-20; distribution of binder on the layer of rubble 14-20; Laying the 2nd layer of rubble 10-14; sputtering binder on a layer of rubble 10-14; laying of the 3rd layer of rubble 6-10; Spraying of the binder on the layer of rubble 6-10; Laying the 4th layer of rubble 4-6; Spraying of the binder on the layer of rubble 4-6; Laying the 5th layer of rubble 2-4 and seal.
It is important to ensure the correct dosing of the binder when spraying the emulsion on the rubble. Crushed stone should only be covered with a film of binder, but not recessed in it. The total consumption of the binder should not exceed the ratio of the knitting: rubble \u003d 1:10 by weight. The number of layers and the size of the rubble fractions depends on the depth of potholes. When repairing small picking depth to 10-15 mm, the repair is performed in the following order: laying a layer of rubble 4-6; spraying binding crushed stone 4-6; Rubble distribution 2-4 and seal.
These methods are applicable in the repair of blackstone and black-breeding coatings on roads with low traffic intensity. The disadvantages of the use of such methods consist in the fact that the presence of a layer of a variable thickness can cause the destruction of the edges of the patch, and the appearance of the patch repeats the outlines of the potholes.
Measuring repair of asphalt concrete coatings using an asphalt heater. The technology of work is greatly simplified in the event of a patch repair with preliminary heating of the asphalt concrete coating throughout the map area. For these purposes, a special self-propelled machine can be used - an asphalt-coat, which allows you to warm up the asphalt concrete coating to 100-200 ° C. The same machine is used to dry into crude weather repaired.
The heating mode consists of two periods: heating the surface of the coating to a temperature of 180 ° C and further smoother heating of the coating across the entire width to a temperature of about 80 ° C at the bottom of the heated layer at a constant temperature on the surface of the coating. The warm-up mode is regulated by changing the gas flow and the height of the burner over the coating from 10 to 20 cm.
After heating, the asphalt concrete coating is loosened by robbles for the entire depth of pothole, it is added to it a new hot asphalt concrete mixture of the thermos bunker, stirred with an old mixture, distributed over the entire width of the card with a layer of more than 1.2-1.3 times, taking into account the seal coefficient and Seal from the edges to the middle of the place repaired by a manual vibratory or self-propelled roller. The pairing places of the old and new coatings are heated using a line of burners that are part of the asphalt-heater. The burner line is a mobile metal frame with infrared radiation burners, which are supplied with gas from cylinders on a flexible hose. During repair work, the coating temperature should be within 130-150 ° C, and by the end of work on the seal - not lower than 100-140 ° C.
The use of the asphalt heater greatly simplifies the technology of displacement and improves the quality of work.
The use of gas-based asphaltological steels requires special attention and compliance with safety regulations. It does not allow the operation of gas burners at wind speeds more than 6-8 m / s, when the flames can be repaid on the burner part of the burner, and the gas of them will flow, concentrates in large quantities and can explode.
Significantly safer asphalt-fuels operating on liquid fuel or with electrical sources of infrared radiation.
Repair of asphalt concrete coatings using special machines for displacement or road repair. The most efficient and qualitative type of patch repair is the repair performed using special machines that are called road detectors. Road degenerates are used as a means of a complex mechanization of road repair work, since with their help not only the meal repair of road surfaces, but also seal cracks and fill seams.
The technological scheme of patching with the use of road degenerate includes conventional operations. If the producer is equipped with a heater, the repair technology is much easier.
Simplified methods of naval repairs (injection methods). In recent years, simplified methods of smelly repairs are more widely distributed using special machines of type "SAVALCO" (Sweden), "Rasco", "Duura Petcher", "Blow Petcher" and others. In Russia, similar cars are produced in the form of special trailed equipment - BCM-24 and UDN-1 grade seal. Repair of the elevation injecting method is performed using a cationic emulsion. Purification of potholes under repair are carried out by jet of compressed air or suction method; Downloading - heated to 60-75 ° C emulsion; Filling - black in the process of injecting rubble. With this method of repairing the stump of edges can not be produced.
As a repair material, crushed stone fraction 5-8 (10) mm and EBC-2 emulsion. Apply a concentrated emulsion (60-70%) on BND 90/130 or 60/90 bitumens with an approximate flow rate of 10-11% of the mass of rubble. The surface of the renovated area is sprinkled with a white rubble layer into one rubble. The movement is open after 10-15 minutes. Works are performed at air temperature not lower than + 5 ° C both dry and wet coating.
The meal repair by the injection method is performed in the following order (Fig. 13.12):
Fig. 13.12. Measuring repairs on simplified technology: 1 - cleaning chosen by purging with compressed air; 2 - brewing a bitumen emulsion; 3 - filling with rubble, processed emulsion; 4 - applying a thin layer of untreated crushed stone
the first stage - the place of the pit or patch is purified by a jet of air under pressure to remove pieces of asphalt concrete, water and garbage;
the second stage is the breaker of the bituminous emulsion of the bottom, the walls of the walls and the surface of the asphalt concrete coating adjacent to it. The emulsion flow is controlled by the control valve on the main nozzle. Emulsion enters the airflow from the splashing ring. The emulsion temperature should be about 50 ° C;
third stage - filling potholes with repair material. Crushed stone is introduced into the air flow using a screw conveyor, then falls into the main mouthpiece, where it is covered with an emulsion from the splashing ring, and from it the treated material with high speed is ejected to the pothole, is distributed with thin layers. The seal occurs due to the forces arising from high velocities of the material being discarded. Control of the suspended flexible sleeve is carried out by the operator remotely;
the fourth stage is the applying layer of dry raw crushed stone to the plot of patch. In this case, the valve on the main nozzle controlling the emulsion flow, is turned off.
It should be noted that the exclusion of the preload of the edges of the pothole leads to the fact that the old asphalt concrete with a disturbed structure, which is usually reduced with a reduced adhesion with the underlying layer remains in the cover zone. The service life of such a patch will be less than with traditional technology. In addition, the patchs have incorrect forms, which worsens the appearance of the coating.
Measuring repairs using cast asphalt concrete mixtures. A distinctive feature of cast asphalt concrete mixtures is that they are placed in fluid state, as a result of which they are easily fill in potholes and do not require seals. Small or sandy cast asphalt can be used to repair at low air temperature (up to -10 ° C). Most often for repair work, a sand-based asphalt concrete mixture is used, consisting of natural or artificial quartz sand in an amount of 85% by weight, mineral powder - 15% and bitumen - 10-12%. For the preparation of cast asphalt, a viscous refractory bitumen with a 40/60 penetration is used. The mixture is prepared in mixing plants with compulsory stirrers at a mixing temperature of 220-240 ° C. Transportation of the mixture to the place of laying is carried out in special mobile boilers like "Kohler" or in thermos bunkers.
The delivered mixture at a temperature of 200-220 ° C is poured into the prepared pothole and easily smoke with wooden glades. The lung mixture fills all the irregularities, due to the high temperature heats up the bottom and walls potholes, as a result of which a durable connection of the repair material from the coating is reached.
Since the fine-grained or sandy-cast mixture creates a surface of the coating with increased slighterness, it is necessary to apply measures to increase its coupling qualities. For these purposes, immediately after the distribution of the mixture, black crushed stone 3-5 or 5-8 is scattered with a flow rate of 5-8 kg / m 2 so that the crushed stone is evenly distributed with a layer in one crushed stone. After cooling the mixture to 80-100 ° C, they roll the crushed stone with a manual rink weighing 30-50 kg. When the mixture cools up to the ambient temperature, extra crushed stone, which has not pushed into the mixture, sweep and open the movement.
Laying cast asphalt concrete mixtures with mellow repair can be carried out manually or a special asphalt paver with a heating system. The advantage of this technology is that operations on repairing a repair card and the mixture seal are excluded, as well as in the high strength of the repair layer and the reliability of the seams of conjugation of new and old materials. Disadvantages are the need to use special mixers, mobile heating rollers and mixers or thermos-bunkers, viscous refractory bitumens, as well as increased safety and safety requirements when working with a mixture having a very high temperature.
In addition, cast asphalt during operation has significantly greater strength and less deformability compared to a conventional asphalt concrete. Therefore, in the case when the cast asphalt is repaired from a conventional asphalt concrete, in a few years this coating begins to collapse around the patch from cast asphalt, which is explained by the difference in the physicomechanical properties of the old and new material. Molded asphalt is used to be all used when the urban roads and streets are used.
One of the ways to simplify the technology of work and an increase in the construction season is the use of cold asphalt concrete mixtures as a repair material on a polymer bituminous binder (PBV). These mixtures are prepared using a complex binder, which consists of a bitumen of 60/90 in an amount of about 80% by weight of the binder, polymer modifying additive in an amount of 5-6% and solvent, such as diesel fuel, in an amount of 15% by weight of the binder. The binding is prepared by mixing the components at a temperature of 100-110 ° C.
The asphalt concrete mixture on the PBW is prepared in mixers with forced stirring at a temperature of 50-60 ° C. The mixture consists of a fine rubble of fractions 3-10 in an amount of 85% by weight of mineral material, drop-down 0-3 in the amount of 15% and a binder in the amount of 3-4% of the total mass of mineral material. The mixture is then stored in an open stack, 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, while maintaining its technological properties, including mobility, plasticity, lack of kellency and high adhesive characteristics.
The repair technology with the use of this mixture is extremely simple: a mixture of car body or from the road repair hopper manually or with the help of the sleeve is supplied to the pitch and smoking, after which the traffic is opened, under the action of which the road layer is forming. The entire repair process of the repair takes 2-4 minutes, since operations on the markup of the card, cutting down and cleaning are selected, as well as the sealing rollers or vibration rips. The adhesion properties of the mixture are preserved and when it is laying it into potholes filled with water. Repair work can be performed at a negative air temperature, the limit of which requires clarification. All this makes the specified method of displacement very attractive for practical purposes.
However, it has a number of essential flaws. First of all, there is a possibility of rapid destruction of renovated potholes due to the fact that its weakened edges are not removed. When performing work in crude 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 when the coating temperature is reduced below 0 to freeze. In this case, the process of destruction of the conjugation zone of new and old materials can be initiated. The second disadvantage of this repair method is to preserve after repairing an irregular external form of potholes, which worsens the aesthetic perception of the road.
The presence of a large number of ways of displacement makes it possible to choose the optimal one on the basis of specific conditions, taking into account the state of the road, the number and size of the coating defects, the presence of materials and equipment, the timing of repair and other circumstances.
In any case, it is necessary to strive for the elimination of vitality at the early stage of its development. After a patch repair in many cases, it is advisable to arrange a surface treatment or lay a protective layer that will give a monotonous appearance of the coating and prevent its destruction.
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