Asphalt service life. Road works technologies

For the last month we have been trying to convince the city administration to increase the guarantee for road repairs. Despite the obvious advantages of the increased warranty for the city, we were faced with a powerful traffic lobby. The city's public chamber sent a letter to Jacob with a request to increase the warranty period; they tried to convince him in every possible way that this was not possible, but in fact, everything is possible. Until May 12, you can make changes to the auction documentation for road repairs in the amount of 434 million rubles, and increase the guarantee from 3 to 5 years.
Within the framework of the Public Chamber, they did everything they could, but they are unable to increase the guarantee. So far we have achieved an intermediate result - an increase in the warranty from three to four years, and then starting next year. I am not happy with this option, and I want to win over the townspeople and the media. Therefore, I ask journalists for help in covering the topic of warranty periods for road repairs. We need a comment from the administration so that they explain why they are not increasing the guarantee for road repairs. Next there will be a fairly long text with the cost of asphalt and references to orders of the Ministry of Transport - this is important to know in order to understand why we suddenly demand an increase in the guarantee.

Until 2013, all roads in the city were repaired with grade I Type “A” asphalt and the contracts included a 3-year guarantee. The cost of a ton of asphalt type “A” in 2001 prices is 497.88 rubles per ton without VAT. Since 2013, we switched to ShchMA asphalt, which costs 735.75 rubles per ton.

By using more expensive ShchMA asphalt, within a limited budget, we reduce the area of roads being repaired. If the warranty period is not extended, the city takes on an additional burden. In the current realities, I think this is not reasonable. Moreover, if the ShchMA asphalt was laid poorly, then in three years it will not be possible to fully understand this, because it resists wear better than grade I type “A”.

Moreover, the order of the Ministry of Transport of the Russian Federation No. IS-414-r dated May 7, 2003. specifies the following warranty periods:

Subgrade	from 8 years
Road base	from 6 years
Bottom layer of coating	from 5 years
Top coating layer	from 4 years
Artificial constructions:
Bridges, overpasses, tunnels, overpasses	from 8 years
Culverts	from 6 years
Regulatory structures (type of structure)	from 6 years
Road arrangement:
Barrier fencing (metal, reinforced concrete)	from 5 years
Signal posts	from 2 years
Road signs	from 2 years
Buildings and structures of operational and motor transport services	from 8 years

Regardless of the intensity of wear and category of the road, as well as the asphalt used, the warranty period for the top layer of the coating must be at least 4 years, and for ShchMA asphalt 5-6 years. But so far it has not been possible to convince the administration to increase the deadline. They refer to the old, no longer valid version of the order of the Ministry of Transport of the Russian Federation 157 dated November 1, 2003, where it was stated that the turnaround time for a road with Mirka asphaltI type “A” - at least 3 tapes. But in the new edition this is not there. Since April 12, 2015, a new reduction of the order has been in force, the changes were made by order 30 of February 25, 2015, now the overhaul cycle is 12 years.

Moreover, it is stated that: “ The turnaround time for major overhauls and repairs of federal highways established by this appendix is accepted when designing road work and is taken into account when forming a program of work for major overhauls and repairs for sections of highways, the design of which was carried out taking into account the time between overhauls specified in this appendix.»

Therefore, the warranty can be from 4 years to 12 years, for asphalt grade I type “A”. The mayor of Polevsky provided a 5-year guarantee.

Personally, I don’t understand why the guarantee has not yet been increased by the administration on its own. And the only explanation for this I see is the actions of the road lobby.
In fact, in most cases, the formation of ruts and holes occurs not because of spikes, but because of a violation of technology or poor-quality asphalt. Here are three examples of streets where cheaper asphalt grade I type "A" was used.

1. Lenin Avenue from 8 March Street to Karl Liebnecht was renovated in 2012, The traffic intensity is more than 30 thousand cars per day, the asphalt has been standing for four years, and no climate, spikes or tanks can destroy the road.

The only area where a rut formed and the top layer of asphalt was worn out was in front of the intersection with 8 March, but there the rut was formed due to the fact that instead of a 10 cm thick layer of asphalt, only 3.5 cm was laid.

2. Mamin-Sibiryak Street, the asphalt was also laid in 2012, already in the fall, a couple of days before winter. The traffic intensity is 20-30 thousand cars per day, the asphalt has been standing for four years and I am sure that such a road will stand for 12 years without major repairs.

But the Tokarei-Gurzufskaya-Repina-S. Deryabina interchange, the new, newly built road fell apart after 4 years, the photographs were taken in 2015, now everything is even worse. This interchange was built by the UralTrassSpetsStroy Trust, which is now building its way through Lenin to Tatishchev.

In four years, both the top and bottom layers on the new road fell apart, there was a three-year warranty! You see a “cobweb”, usually contractors say that this is not a warranty issue and the pillow is to blame. How could a pillow deteriorate in 4 years?

Have you ever seen a new road in Europe fall apart within 4 years? The main reason for bad roads is not in thorns or climate, but in the hands of road builders - they simply do not know how to repair roads. It’s like a migrant worker who has been laying tiles crookedly for 10 years, he has a lot of experience in fraud, but it’s normal, according to GOST, he won’t be able to lay tiles, or he can lay them if he constantly creates an atmosphere of anxiety.

Therefore, if we are talking about improving the quality of roads, we need to start with increasing warranty periods and operational control, that is, in the summer, make sure that asphalt is not put in puddles or in the rain. If we don’t do it ourselves, no one will do it!

Request to residents: please share this post on your social networks, maybe it will help and the guarantee will be increased!

Asphalt road surfaces are common and extremely popular. This is due, first of all, to the durability and strength of this option. For these conditions to be fully met, a number of conditions must be met. The technology of laying asphalt has certain difficulties, but if everything is done correctly, the costs will be recouped with impeccable coverage and trouble-free operation.

Types of asphalt pavement

In the production of asphalt mixtures, bituminous materials (resins), as well as reinforcing filler, are used. Its role is played by coarse sand and mineral rocks of a certain fraction. All materials must be of good quality, and depending on the type and purpose of the coating, other ingredients are added to the composition.

Types of asphalt:

First class coatings. They are used for laying routes and can withstand heavy loads. The technology involves the use of mineral filler up to four centimeters in size. Such coatings can withstand the weight of loaded vehicles and intensive use.
Second class coatings. They are used for paving squares, sidewalks and pedestrian roads. The largest inclusions of the asphalt mixture reach 25 mm.
Third class coatings. The priority in this case will be the plasticity of the mixture. Mineral particles of minimal size (up to 15 mm), which allows for a tight fit of the composition. This type of coating is used for non-vehicular use (private courtyards, institutional areas, sports grounds).

Proportions and manufacturing standards are regulated by GOST, but many manufacturers ignore this rule and use cheap substitutes. This does not reflect well on the quality of the asphalt mixture, so it is preferable to order this product from truly trusted companies, for example, representative offices of the Road Technologies company.

Application technologies:

Hot asphalt. Its installation technology requires the use of special equipment, as well as compliance with a number of conditions. First of all, this is the temperature of the finished mixture and the ambient air. It is unacceptable to lay cooled asphalt, or to carry out work at sub-zero temperatures. The second important point is the speed of laying hot asphalt. If the work is not performed in accordance with GOST, the quality of the coating will be poor. Hot asphalt is used to lay new roads and sidewalks. After application, the coating should not be used for some time to ensure sufficient adhesion.
Cold asphalt. Its standards are also regulated by GOST and SNIP, but in production other grades of bitumen are used, which harden faster and do not require a certain temperature. Cold asphalt can be laid in a wider range of ambient temperatures (up to -5ºС is allowed). Most often, this method is used when performing pothole repairs of roads, or to perform asphalt paving on your own.

You can purchase cold asphalt not only directly from the manufacturer, but also in construction stores. Airtight containers allow you to preserve its characteristics for up to several months. At the same time, in terms of strength and service life, the cold mixture is significantly inferior to the alternative option, so the use on busy roads or places of active use is somewhat limited.

Preparatory work before laying asphalt

An important condition for proper installation is compliance with the requirements of GOST and SNIP for surface preparation. These standards provide for several stages, on which the quality of the future road will also depend.

How to prepare the surface:

Clear and mark the asphalt paving area. If necessary (swampy areas, possible problems with the soil), geodetic surveys are carried out.
The top layer of soil is completely removed. For highways it is possible to build a special embankment, but for a pedestrian road made of asphalt this is not required.
A sand “cushion” is poured into the bottom of the trench, after which it is necessary to install a special material - geotextiles. It will prevent the displacement of large fractions of building materials into the sand.
It is necessary to fill the resulting pit with crushed stone of different sizes. The fraction of the material will depend on the purpose of the coating. The largest crushed stone is used for laying highways. The layers are arranged in descending order from coarse to fine-grained materials.
The number of preparatory layers also depends on the further use of the road. After installation, the material is well pressed with a special roller. This will ensure reliable coupling, eliminating possible operational problems.
To strengthen and prevent cracks from appearing on the finished coating, a reinforcing mesh is used.

GOST for laying asphalt regulates all possible nuances associated with the implementation of such a coating. This process is complex, because even with special equipment, most of the work still requires manual labor.

How is asphalt paving done?

The rules for laying asphalt mostly depend on the type and purpose of the coating, but some standards cannot be changed. Such rules are clearly stated in GOST and SNIP, and they ensure the durability and quality of future roads and sidewalks.

According to GOST requirements, asphalting of roads and sidewalks must be carried out under suitable weather conditions. The production of the mixture is also determined by the standards of these documents. Laying asphalt SNIP (building codes and regulations) also determines the quality of the finished work, from the stage of preparatory work to the final cycle.

Basic requirements of the standards:

Immediately before laying asphalt, heated bitumen or bitumen emulsion is applied to the prepared surface.
Laying hot asphalt should be carried out exclusively at positive air temperatures (not lower than 5 degrees).
The mixture must be at a certain temperature, so before application it is kept hot (not lower than 100 degrees).
The thickness of the asphalt mixture layer is determined by the purpose of the coating. Asphalt is applied in sections of a certain length, after which it is leveled and compacted.
Compaction of the layer must begin immediately after backfilling. For this purpose, special equipment is used - a roller, a brick press or an asphalt paver.
The applied layer should harden for at least a day, but for cold asphalt this time can be only a couple of hours.

Modern additives - plasticizers allow installation even at sub-zero temperatures. This mixture is called asphalt concrete. It is quite expensive and is most often used for emergency road repairs in winter.

Final works

After asphalting, a special impregnation must be applied to the section of the future road. It provides tight adhesion to asphalt and gives the coating an attractive appearance.

The following impregnation options are distinguished:

Asphalt emulsion. Among all types, this is the most affordable mixture, but does not always live up to expectations. Most often used for sections of road without heavy traffic or sidewalks.
Coal tar. A reliable base, which also gives the finished coating an aesthetic appeal. It is not affected by petroleum products and has a long service life.
Acrylic polymers. Adding special components to the mixture allows you to obtain an elastic and durable coating. It is even possible to change the color, which is used for additional decoration of the area.

When choosing a finishing layer, it is worth considering not only the financial issue, but also the main purpose of the project. When choosing a mixture, you need to take into account how intensively the road surface is used.

Creating an asphalt surface is an important process, because it determines the quality and durability of future roads and sidewalks. The classification of mixtures and the application process are determined by the requirements of GOST and SNIP, as well as the types of road work. In order for the coating to last as long as possible even under intense load, it is important to choose a reliable manufacturer. "Road Technologies" guarantees speed of execution and compliance with all quality requirements.

GOST R 54401-2011

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

Public roads

HOT CAST ROAD ASPHALT CONCRETE

Technical requirements

Automobile roads of general use. Hot road mastic asphalt. Technical requirements

OKS 93.080.20

Date of introduction 2012-05-01

Preface

1 DEVELOPED by the Autonomous Non-Profit Organization "Research Institute of Transport and Construction Complex" (ANO "NII TSK") and Open Joint Stock Company "Asphalt Concrete Plant No. 1", St. Petersburg (JSC "ABZ-1", St. Petersburg)

2 INTRODUCED by the Technical Committee for Standardization TC 418 "Road Facilities"

3 APPROVED AND ENTERED INTO EFFECT by Order of the Federal Agency for Technical Regulation and Metrology dated September 14, 2011 N 297-st

4 This standard has been developed taking into account the main regulatory provisions of the European standard EN 13108-6:2006 * "Bituminous mixtures - Material specifications - Part 6: Cast asphalt" (EN 13108-6:2006 "Bituminous mixtures - Material specifications - Part 6: Mastic Asphalt", NEQ)
________________
* Access to international and foreign documents mentioned in the text can be obtained by contacting Customer Support. - Database manufacturer's note.

5 INTRODUCED FOR THE FIRST TIME

6 REPUBLICATION. October 2019

The rules for the application of this standard are established in Article 26 of the Federal Law of June 29, 2015 N 162-FZ "On Standardization in the Russian Federation" . Information about changes to this standard is published in the annual (as of January 1 of the current year) information index "National Standards", and the official text of changes and amendments is published in the monthly information index "National Standards". In case of revision (replacement) or cancellation of this standard, the corresponding notice will be published in the next issue of the monthly information index "National Standards". Relevant information, notices and texts are also posted in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet (www.gost.ru)

1 area of use

This standard applies to hot cast road asphalt concrete and hot cast asphalt road mixtures (hereinafter referred to as cast mixtures) used for the construction of coatings on public roads, bridge structures, tunnels, as well as for the production of pothole repairs, and establishes technical requirements for them .

2 Normative references

This standard uses normative references to the following standards. For dated references, only the edition of the referenced standard applies; for undated references, the latest edition (including any amendments) applies:

GOST 12.1.004 System of occupational safety standards. Fire safety. General requirements

GOST 12.1.005 System of occupational safety standards. General sanitary and hygienic requirements for the air in the working area

GOST 12.1.007 System of occupational safety standards. Harmful substances. Classification and general safety requirements

GOST 12.3.002 System of occupational safety standards. Production processes. General safety requirements

GOST 17.2.3.02 Rules for establishing permissible emissions of harmful substances by industrial enterprises

GOST 8267 Crushed stone and gravel from dense rocks for construction work. Specifications

GOST 8269.0 Crushed stone and gravel from dense rocks and industrial waste for construction work. Methods of physical and mechanical tests

GOST 8735 Sand for construction work. Test methods

GOST 8736 Sand for construction work. Specifications

GOST 22245 Viscous petroleum road bitumens. Specifications

GOST 30108 Construction materials and products. Determination of specific effective activity of natural radionuclides

GOST 31015 Mixtures of asphalt concrete and asphalt concrete crushed stone-mastic. Specifications

GOST R 52056 Polymer-bitumen road binders based on block copolymers of the styrene-butadiene-styrene type. Specifications

GOST R 52128 Bitumen road emulsions. Specifications

GOST R 52129 Mineral powder for asphalt concrete and organomineral mixtures. Specifications

GOST R 54400 Public automobile roads. Hot cast road asphalt concrete. Test methods

Note - When using this standard, it is advisable to check the validity of the reference standards in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet or using the annual information index "National Standards", which was published as of January 1 of the current year, and on issues of the monthly information index "National Standards" for the current year. If an undated reference standard is replaced, it is recommended that the current version of that standard be used, taking into account any changes made to that version. If a dated reference standard is replaced, it is recommended to use the version of that standard with the year of approval (adoption) indicated above. If, after the approval of this standard, a change is made to the referenced standard to which a dated reference is made that affects the provision referred to, it is recommended that that provision be applied without regard to that change. If the reference standard is canceled without replacement, then the provision in which a reference to it is given is recommended to be applied in the part that does not affect this reference.

3 Terms and definitions

The following terms with corresponding definitions are used in this standard.

3.1 hot cast road asphalt concrete: Hot cast asphalt concrete road mixture, frozen during the cooling process and formed in the coating.

3.2 asphalt granulate: A material obtained by milling an existing asphalt concrete pavement (recycled asphalt concrete).

3.3 leveling layer: A layer of variable thickness that is applied to an existing layer or surface in order to create the desired surface profile for the installation of the next structural layer of uniform thickness.

3.4 astringent (astringent): An organic compound (viscous road bitumen, modified bitumen) designed to connect the grains of the mineral part of the cast mixture together.

3.5 reflux condenser: Special additives based on natural waxes and synthetic paraffins with a melting point from 70°C to 140°C, used to modify petroleum binders in order to reduce their viscosity.

3.6 additive: A component that can be added to a mixture in certain quantities to influence the properties or color of the mixture.

3.7 road surface: A structure consisting of one or several layers that absorbs loads from transport and ensures its unhindered movement.

3.8 specified mixture composition (mixture composition): The optimally selected composition of a certain asphalt concrete mixture, indicating the curve of the granulometric composition of the mineral part of the mixture and the percentage of components.

3.9 acidic rocks: Igneous rocks containing more than 65% silicon oxide ().

3.10 kocher (mobile kocher): A special mobile thermos boiler for transporting the cast mixture, equipped with heating, a mixing system (with or without an autonomous drive) and instruments to control the temperature of the cast mixture.

3.11 "hot" method: The technological process of creating a rough surface of the top layer of a road surface by applying a grain mineral mixture (fractionated sand or crushed stone) or blackened crushed stone to a cast mixture that has not yet cooled down after laying.

3.12 modified bitumen: A binder made from viscous road bitumen by introducing polymers (with or without plasticizers) or other substances in order to impart certain properties to the bitumen.

3.13 bridge structure: A road engineering structure (bridge, overpass, viaduct, overpass, aqueduct, etc.), consisting of one or more spans and supports, laying a transport or pedestrian path over obstacles in the form of watercourses, reservoirs, canals, mountain gorges, city streets , railways and roads, pipelines and communications for various purposes.

3.14 main rocks: Igneous rocks containing from 44% to 52% silicon oxide ().

3.15 coating surface: The top layer of the road surface that comes into contact with traffic.

3.16 polymer-bitumen binder (PBB): Polymer-modified viscous road bitumen.

3.17 complete passage of mineral material: The amount of material whose grain size is smaller than the size of the openings of a given sieve (the amount of material passing through a given sieve when sifted).

3.18 total remainder of mineral material: The amount of material whose grain size is larger than the size of the holes of a given sieve (the amount of material that did not pass through a given sieve when sifted).

3.19 row (laying strip): An element of pavement laid in one work shift or work day.

3.20 segregation (stratification): Local change in the granulometric composition of the mineral materials of the cast mixture and the binder content in the initially homogeneous mixture, due to separate movements of particles of the large and small fractions of the mineral part, during the storage of the mixture or its transportation.

3.21 layer (structural layer): A structural element of a road surface consisting of a material of the same composition. The layer can be laid in one or several rows.

3.22 Hot asphalt concrete road mixture: Casting mixture with minimal residual porosity, consisting of a grain mineral part (crushed stone, sand and mineral powder) and viscous petroleum bitumen (with or without polymer or other additives) as a binder, laid using casting technology, without compaction , at a mixture temperature of at least 190°C.

3.23 medium rocks: Igneous rocks containing from 52% to 65% silicon oxide ().

3.24 stationary kocher: A special stationary storage bin for homogenization and storage of the cast mixture after the end of its production process, equipped with heating, a mixing system, a shipping device and devices for monitoring the temperature of the cast mixture.

3.25 workability: The qualitative characteristic of a cast mixture, determined by the efforts that ensure its homogenization during mixing, its suitability for transportation and installation. Includes such properties of the cast mixture as fluidity, suitability for installation using casting technology, and speed of spreading over the surface.

3.26 blackened crushed stone: Fractionated crushed stone treated with bitumen, in an unbound state and intended to create a surface rough layer.

4 Classification

4.1 Cast mixtures and asphalt concrete based on them, depending on the largest grain size of the mineral part, the crushed stone content in them and their purpose, are divided into three types (see Table 1).

Table 1


Main classification features of cast mixtures		Purpose
	Maximum grain size of the mineral part, mm
		New construction, major and pothole repairs
		New construction, major and pothole repairs, sidewalks
		Sidewalks, bike paths

5 Technical requirements

5.1 Cast mixtures must be prepared in accordance with the requirements of this standard according to technological regulations approved in the prescribed manner by the manufacturer.

5.2 The grain compositions of the mineral part of mixtures of cast and asphalt concrete based on them, when using round sieves, must correspond to the values indicated in Table 2.

table 2


Mixture type	Grain size, mm, finer*




* Complete passes of mineral material, as a percentage by weight.

The grain compositions of the mineral part of mixtures of cast and asphalt concrete based on them, when using square sieves, are given in Appendix B.

Graphs of the permitted particle size distribution of the mineral part of the cast mixture are given in Appendix B.

5.4 Indicators of physical and mechanical properties of mixtures of cast and asphalt concrete based on them, production, storage and laying temperatures must correspond to those indicated in Table 3.

The physical and mechanical properties of mixtures of cast and asphalt concrete based on them are determined in accordance with GOST R 54400.

Table 3


Indicator name	Standards for types of mixtures

1 Porosity of the mineral framework, % by volume, no more			Not standardized
2 Residual porosity, % by volume, no more			Not standardized
3 Water saturation, % by volume, no more
4 Temperature of the mixture during production, transportation, storage and installation, °C, not higher	215* 230**	215* 230**	215* 230**
5 Tensile strength upon splitting at 0 °C, MPa (optional):			Not standardized

no more
Values correspond to the maximum temperature of the mixture from the conditions for using polymer-bitumen binders. * The values correspond to the maximum temperature of the mixture from the conditions for using viscous petroleum road bitumens.

5.5 The maximum temperature indicated in Table 3 is valid for any location in the mixing mechanism and storage and transport container.

5.6 The values of the stamp indentation depth, depending on the purpose and place of application of mixtures of cast and asphalt concrete based on them, are indicated in Table 4.

Table 4


Application area	Type of work	Range of stamp indentation indicator for types of mixtures, mm

1 Public roads with a traffic intensity of 3000 vehicles/day; bridge structures, tunnels.		From 1.0 to 3.5 Increase after 30 min No more than 0.4 mm		Not applicable
		From 1.0 to 4.5 Increase after 30 min No more than 0.6 mm
2 Public roads with a traffic volume of 3000 vehicles/day	Installation of the top layer of coating	From 1.0 to 4.0 Increase after 30 min No more than 0.5 mm		Not applicable
	Installation of the bottom layer of coating	From 1.0 to 5.0 Increase after 30 min No more than 0.6 mm
3 Pedestrian and bicycle paths, crossings and sidewalks	Installation of top and bottom layers of coating	Not applicable	from 2.0 to 8.0*	from 2.0 to 8.0*
4 All types of roads, as well as bridges and tunnels	Pothole repair of the top layer of coating; leveling layer device	From 1.0 to 6.0 Increase after 30 min No more than 0.8 mm		Not applicable
* The increase in the stamp indentation rate over the next 30 minutes is not standardized.

The indicator of the depth of indentation of the stamp at a temperature of 40°C during the first 30 minutes of testing and (if necessary) increasing the depth of indentation of the stamp during the next 30 minutes of testing is determined in accordance with GOST R 54400.

5.7 Cast mixtures must be homogeneous. The homogeneity of cast mixtures is assessed in accordance with GOST R 54400 by the coefficient of variation of the values of the stamp indentation depth at a temperature of 40°C during the first 30 minutes of testing. The coefficient of variation for mixtures of cast types I and II should be no more than 0.20. This indicator for cast mixture type III is not standardized. The homogeneity indicator of the cast mixture is determined at intervals of no less than monthly. It is recommended to determine the homogeneity index of the cast mixture for each produced composition.

5.8 Material requirements

5.8.1 To prepare cast mixtures, crushed stone is used, obtained by crushing dense rocks. Crushed stone from dense rocks, which is part of cast mixtures, must comply with the requirements of GOST 8267.

To prepare cast mixtures, crushed stone of fractions from 5 to 10 mm is used; over 10 to 15 mm; over 10 to 20 mm; over 15 to 20 mm, as well as mixtures of these fractions. There should be no foreign contaminants in the crushed stone.

The physical and mechanical properties of crushed stone must meet the requirements specified in Table 5.

Table 5


Indicator name	Indicator values	Test method
1 Grade according to crushability, not less
2 Abrasion grade, no less
3 Frost resistance grade, not lower
4 Weighted average content of lamellar (flaky) and needle-shaped grains in a mixture of crushed stone fractions, % by weight, no more


7 Specific effective activity of natural radionuclides, , Bq/kg:

5.8.2 To prepare cast mixtures, sand from crushed screenings, natural sand, and a mixture of them are used. Sand must meet the requirements of GOST 8736. When producing mixtures cast for the top layers of roads and bridge structures, sand from crushed screenings or its mixture with natural sand containing no more than 50% natural sand should be used. The grain composition of natural sand should correspond in size to sand not lower than the fine group.

The physical and mechanical properties of sand must meet the requirements specified in Table 6.

Table 6


Indicator name	Indicator values	Test method
1 Strength grade of sand from crushing screenings (initial rock), not lower


4 Specific effective activity of natural radionuclides, , Bq/kg:
For road construction within populated areas;
For road construction outside populated areas

5.8.3 For the preparation of cast mixtures, non-activated and activated mineral powder is used, meeting the requirements of GOST R 52129.

The permissible content of powder from sedimentary (carbonate) rocks from the total mass of mineral powder must be at least 60%.

It is allowed to use technical dust from the ablation of basic and medium rocks from the dust collection system of mixing plants in an amount of up to 40% of the total mass of the mineral powder. The use of acidic rock entrainment dust is permitted provided that it is contained in an amount of no more than 20% in the total mass of mineral powder. The values of blow dust indicators must comply with the requirements of GOST R 52129 for MP-2 grade powder.

5.8.4 To prepare cast mixtures, petroleum road viscous bitumens of the grades BND 40/60, BND 60/90 in accordance with GOST 22245 are used as a binder, as well as modified and other bitumen binders with improved properties in accordance with regulatory and technical documentation agreed upon and approved by the customer in in accordance with the established procedure, provided that the quality indicators of asphalt concrete cast from these mixtures are ensured at a level not lower than those established by this standard.

5.8.5 When using cast asphalt concrete on bridge structures, in the upper and lower layers of road surfaces with high traffic intensity and design axle loads, polymer-modified bitumens should be used. In these cases, preference should be given to polymer-bitumen binders based on block copolymers of the styrene-butadiene-styrene type, grades PBB 40 and PBB 60 according to GOST R 52056.

5.8.6 When designing the compositions of cast mixtures, the type of binder must be assigned taking into account the climatic characteristics of the construction area, the purpose and place of application of the structural layer, the required (designed) deformation properties of cast mixtures and asphalt concrete based on them. The suitability of the binder for achieving the required functional characteristics of mixtures of cast and asphalt concrete based on them is confirmed during the mandatory and optional tests specified in GOST R 54400.

5.8.7 In the production of cast mixtures, it is permissible to use binders modified by introducing reflux condensers into their composition, which make it possible to reduce the temperature of production, storage and laying of cast mixtures by 10°C to 30°C without compromising their workability. Dephlegmators are introduced into bitumen (polymer-bitumen binder) or into the cast mixture during its production at an asphalt mixing plant.

5.8.8 The specified composition of the cast mixture must be ensured during its production at an asphalt mixing plant. It is prohibited to change the composition of the cast mixture after completion of its production process by introducing binders, petroleum products, plasticizers, resins, mineral materials and other substances into the mobile kocher in order to change the viscosity of the cast mixture and the physical and mechanical characteristics of cast asphalt concrete.

5.8.9 It is permitted to use recycled asphalt concrete (asphalt granulate) as a filler in the cast mixture. Moreover, its content should not exceed 10% of the mass fraction of the composition of the cast mixture for the installation of the lower or upper layers of the road surface and patching and 20% of the mass fraction of the composition of the cast mixture for the installation of a leveling layer. At the request of the consumer, the permissible percentage of asphalt granulate in the cast mixture can be reduced. The maximum grain size of crushed stone contained in asphalt granulate should not exceed the maximum grain size of crushed stone in the cast mixture. When designing the compositions of cast mixtures using asphalt granulate, the mass fraction of the content and properties of the binder in the composition of this aggregate should be taken into account.

6 Safety and environmental requirements

6.1 When preparing and laying cast mixtures, general safety requirements in accordance with GOST 12.3.002 and fire safety requirements in accordance with GOST 12.1.004 must be observed.

6.2 Materials for the preparation of cast mixtures (crushed stone, sand, mineral powder and bitumen) must correspond to hazard class no higher than IV according to GOST 12.1.007, being classified as low-hazard substances in terms of the nature of their harmfulness and the degree of impact on the human body.

6.3 The standards for maximum permissible emissions of pollutants into the atmosphere during the work process should not exceed the values established by GOST 17.2.3.02.

6.4 The air in the working area during the preparation and laying of cast mixtures must meet the requirements of GOST 12.1.005.

6.5 The specific effective activity of natural radionuclides in cast mixtures and cast asphalt concrete should not exceed the values established by GOST 30108.

7 Acceptance rules

7.1 Acceptance of cast mixtures is carried out in batches.

7.2 A batch is considered to be any quantity of a cast mixture of the same type and composition, produced at an enterprise in one mixing plant during one shift, using raw materials from one delivery.

7.3 To assess the compliance of cast mixtures with the requirements of this standard, acceptance and operational quality control is carried out.

7.4 Acceptance control of the cast mixture is carried out for each batch. During acceptance tests, water saturation, the depth of indentation of the stamp and the composition of the cast mixture are determined. The indicators of the porosity of the mineral skeleton and residual porosity and the indicator of the specific effective activity of natural radionuclides are determined when selecting the composition of the cast mixture, as well as when changing the composition and properties of the starting materials.

7.5 During operational quality control of cast mixtures in production, the temperature of the cast mixture in each shipped vehicle is determined, which must be at least 190°C.

7.6 For each batch of cast mixture shipped, the consumer is issued a quality document containing the following information about the product:

- name of the manufacturer and its address;

- number and date of issue of the document;

- name and address of the consumer;

- order number (batch) and quantity (weight) of the cast mixture;

- type of cast mixture (composition number according to the manufacturer’s nomenclature);

- temperature of the cast mixture upon shipment;

- brand of binder used and designation of the standard according to which it was produced;

- designation of this standard;

- information about the introduced additives and asphalt granulate.

At the request of the consumer, the manufacturer is obliged to provide the consumer with complete information about the released batch of products, including data from acceptance tests and tests carried out during the selection of the composition, according to the following indicators:

- water saturation;

- depth of indentation of the stamp (including an increase in the indicator after 30 minutes);

- porosity of the mineral part;

- residual porosity;

- homogeneity of the cast mixture (based on the test results of the previous period);

- specific effective activity of natural radionuclides;

- granulometric composition of the mineral part.

7.7 The consumer has the right to control the compliance of the supplied cast mixture with the requirements of this standard, observing the methods of sampling, sample preparation and testing specified in GOST R 54400.

8 Test methods

8.1 The porosity of the mineral core, residual porosity, water saturation, stamp indentation depth, composition of the cast mixture, tensile strength during splitting of cast asphalt concrete are determined according to GOST R 54400.

If square sieves are used when selecting grain compositions to determine the grain composition of a cast mixture, it is necessary to use a set of sieves in accordance with Appendix B.

8.2 Preparation of samples from mixtures of cast and asphalt concrete based on them for testing is carried out in accordance with GOST R 54400.

8.3 The temperature of the cast mixture is determined by a thermometer with a measurement limit of 300°C and an error of ±1°C.

8.4 The specific effective activity of natural radionuclides is taken according to its maximum value in the mineral materials used. This data is indicated in the quality document by the supplier company.

In the absence of data on the content of natural radionuclides, the manufacturer of the cast mixture carries out incoming inspection of materials in accordance with GOST 30108.

9 Transportation and storage

9.1 Prepared cast mixtures must be transported to the place of installation in kochers. It is not allowed to transport the cast mixture in dump trucks or other vehicles in the absence of installed and functioning mixing and temperature maintenance systems.

9.2 The maximum temperature of the cast mixture during storage must correspond to the values indicated in Table 3 or the requirements of technological regulations for this type of work.

9.3 Mandatory conditions for transporting cast mixtures to the place of installation:

- forced mixing;

- elimination of segregation (stratification) of the cast mixture;

- protection from cooling and precipitation.

9.4 In case of long-term transportation or storage of the cast mixture in stationary containers at asphalt mixing plants, its temperature should be reduced for the period of the expected storage time. When storing cast mixtures for 5 to 12 hours, their temperature should be lowered to 200°C (when using polymer-bitumen binders) or to 215°C (when using viscous petroleum bitumen). After the end of the storage period, immediately before laying work, the temperature of the cast mixture is increased to the permissible values indicated in Table 3 or in the technological regulations for this type of work.

9.5 The time elapsed from the production of the cast mixture at the asphalt mixing plant to its complete unloading from the mobile kocher when laying it in the coating should not exceed 12 hours.

9.6 The cast mixture is subject to disposal as construction waste if the following conditions are met:

- exceeding the maximum permissible shelf life of the cast mixture;

- unsatisfactory workability of the mixture, loss of the ability to be a cast mixture and the ability to spread over the base, friability (inconsistency), the presence of brown smoke emanating from the cast mixture.

9.7 Instrumentation that monitors the temperature of the cast mixture at the asphalt mixing plant and in the pit (stationary and mobile) must be subject to calibration (verification) at least once every three months.

10 Directions for use

10.1 The installation of coatings from the cast mixture is carried out in accordance with the technological regulations approved in the prescribed manner.

10.2 The cast mixture must be placed into the coating exclusively in a liquid or viscous flow state that does not require compaction.

10.3 Laying of cast mixtures should be carried out at a temperature of the ambient air and the underlying structural layer of at least 5°C. It is allowed to use cast mixtures at ambient temperatures down to minus 10°C for carrying out work to relieve emergency situations on the carriageway of roads with asphalt concrete surfaces. In these cases, measures should be taken to ensure sufficient quality of adhesion between cast asphalt concrete and the underlying structural layer.

10.4 Cast mixtures for the construction of road surfaces, sidewalks and pothole repairs must be unloaded directly onto the surface of the underlying structural layer or waterproofing layer. The surface of the underlying layer must be dry, clean, dust-free and must meet the requirements for asphalt concrete and monolithic cement concrete bases and coatings.

When laying a cast mixture on a concrete base or asphalt concrete pavement prepared by cold milling, such surfaces should be pre-treated with bitumen emulsion in accordance with GOST R 52128 with a flow rate of 0.2-0.4 l/m in order to ensure proper adhesion of the layers. Accumulation of emulsion in low areas of the base surface is not allowed. It is mandatory to require complete disintegration of the emulsion and evaporation of the resulting moisture before laying the cast mixture. The use of bitumen instead of bitumen emulsion for surface treatment is not allowed.

Emulsion treatment of the underlying layer of cast asphalt concrete is not carried out when the lower and upper layers of the coating are made of cast asphalt concrete.

It is allowed not to treat the underlying layer of cast asphalt concrete with an emulsion when constructing the top layer of crushed stone-mastic asphalt concrete mixture in accordance with GOST 31015 with a time interval between laying layers of no more than 10 days, as well as in the absence of traffic during this period on the underlying layer.

10.5 The value of the maximum permissible longitudinal and transverse slopes of the road structure, when using a cast mixture, ranges from 4% to 6%, depending on the characteristics of the given composition of the cast mixture and its viscosity.

10.6 Cast mixtures of all types may be laid either mechanically using a special device for leveling the cast mixture (finisher), or manually. The required workability of cast mixtures is achieved by the manufacturer by adjusting the specified composition and selection of bitumen binder, introducing reflux condensers during the production of the cast mixture, provided that the cast asphalt concrete maintains the strength characteristics specified in 5.4. Workability can be adjusted by changing the temperature regime of the cast mixture during its laying, taking into account the requirements for the minimum and maximum permissible temperatures of the cast mixture. A mixture intended for mechanized placement may have increased viscosity and a lower rate of spreading over the surface during unloading.

10.7 The final stage of constructing a road surface with a top layer of cast asphalt concrete is the installation of a rough surface, carried out by the “hot” embedding method in accordance with the technological regulations approved in the prescribed manner.

10.8 The physical and mechanical properties of crushed stone used to create a rough surface for the top layer of asphalt concrete pavement cast by the hot embedding method must comply with the requirements given in Appendix A.

Appendix A (recommended). Physico-mechanical characteristics of crushed stone used for the construction of a rough surface of the upper layers of hot cast asphalt concrete road pavement using the hot embedding method

To create a rough surface of the upper layers of road cast hot asphalt concrete using the hot embedding method, fractionated crushed stone of igneous rocks of fractions from 5 to 10 mm, over 10 to 15 mm and mixtures of fractions from 5 to 20 mm according to GOST 8267 with a consumption of 10 -15 kg/m.

When constructing the lower layers of coatings from cast mixtures, in order to additionally ensure adhesion to the upper layers of coatings from all types of compacted asphalt concrete, crushed igneous rocks of fractions from 5 to 10 mm are distributed “hot” with a flow rate of 2-4 kg/m. It is allowed not to sprinkle the bottom layer with crushed stone when installing two-layer coatings made of cast asphalt concrete, provided that there is no movement on the bottom layer of the coating.

To ensure proper adhesion of surface-treated crushed stone to cast asphalt concrete, it is recommended to use crushed stone treated with bitumen (blackened crushed stone). The bitumen content must be selected so as to prevent its runoff, sticking of crushed stones or uneven coverage of the crushed stone surface with bitumen.

The physical and mechanical properties of crushed stone used to create a rough surface for the upper layers of asphalt concrete pavement cast by embedding must meet the requirements presented in Table A.1.

Table A.1

- for road construction within populated areas;


Indicator name	Indicator values	Test method
Rock crushability grade, not lower
Grade for rock abrasion, not lower
Frost resistance grade, not lower
Weighted average content of lamellar (flaky) and needle-shaped grains in a mixture of crushed stone fractions, % by weight, no more

			No more than 740
For road construction outside populated areas	No more than 1350

The recommended temperature range of the cast mixture at the beginning of the process of distribution of grain mineral materials over its surface is from 140°C to 180°C and must be clarified during the production process.

To create a rough surface for pedestrian paths, sidewalks and bicycle paths, natural fractionated sand is used with a consumption of 2-3 kg/m.

The recommended grain composition of natural sand is determined by the total residues on the control sieves given in Table A.2.

Table A.2


	Test sieves size, mm

Total residues, % by weight

It is acceptable to use crushed fractionated sand with a grain size from 2.5 to 5.0 mm and a consumption of 4-8 kg/m.

Appendix B (recommended). Complete passages of mineral material using square sieves

B.1 Complete passages of mineral material when using square sieves as a percentage by weight are given in Table B.1.

Table B.1


Types of mixtures	Grain size, mm, finer
		0,063 (0,075)

Table B.2


Mixture type

Appendix B (recommended). Requirements for the granulometric composition of the mineral part of all types of mixtures

The permitted values for the composition of the mineral part for all types of mixture are in the zone between the two broken lines shown in the graphs of Figures B.1-B.6.

Figure B.1 - Grain composition of type I mixture (round sieves)

Figure B.2 - Grain composition of type I mixture (square sieves)

Figure B.3 - Grain composition of type II mixture (round sieves)

Figure B.4 - Grain composition of type II mixture (square sieves)

Figure B.5 - Grain composition of type III mixture (round sieves)


UDC 691.167:006.354	OKS 93.080.20
Key words: hot cast asphalt road mixtures, hot cast asphalt road concrete, road surfaces

Electronic document text
prepared by Kodeks JSC and verified against:
official publication
M.: Standartinform, 2019

Laying asphalt is a rather complex and labor-intensive process, but at the same time an effective way to construct a road surface. The range of work performed includes: excavation work, foundation installation, asphalt laying, and landscaping.

The work performed at a professional level will not only create a reliable and stable road surface, but will also ensure its long-term service life. Specialists START CITY GROUP will help you choose the best base and material for laying asphalt, based on your wishes.

Characteristic

Asphalt (or asphalt concrete mixture) is a rationally selected mixture based on mineral materials, which include sand, crushed stone, mineral powder, and liquid bitumen. All substances are selected in optimal quantities and mixed while heated.

The crushed stone included in the mixtures must comply with the requirements of GOST 8267 and GOST 3344. It is allowed to use gravel or crushed stone produced according to foreign standards, provided that their quality meets the established Russian standards.

The scope of application of asphalt concrete is wide: construction of roadways, squares, sidewalks, parking areas, park areas for cyclists, airfields, flooring in industrial buildings and in many other areas.

Today, asphalt concrete mixtures, depending on the mineral component, are divided into:

Sandy;
Crushed stone;
Gravel.

The structure of each type has its own characteristics, which determine the effectiveness of using the selected material.

Also, asphalt concrete mixtures are classified depending on the size of the mineral grains:

Fine-grained - less than 2 cm;
Coarse-grained – up to 4 cm.
Sandy – up to 1 cm.

The amount of solid filler contained in the mixture determines which group the asphalt concrete belongs to. There are 3 groups: A, B, C.

Laying technology. Stages. Materials

Today, two road construction technologies are used:

hot paving;
cold asphalting.

Each of them has its pros and cons:

Hot asphalting. The mixture is prepared from viscous and liquid petroleum bitumen. Laying can be done in winter. The temperature of the mixture should not be less than 120 degrees. Before laying the asphalt, the piece of road on which the asphalt concrete mixture will be applied is dried using special equipment.
Cold asphalting. The mixture is prepared from liquid petroleum road bitumen. Laying work is carried out only in the warm season, since water is not dried using this technology. Cold asphalt paving is often used for pothole repair.

Professional paving work requires significant financial investments. After all, for this it is necessary to attract special equipment and experienced qualified specialists.

Laying asphalt consists of several stages:

1. Development of design and estimate documentation

Each site is individual: it has a unique size, topography and configuration, soil characteristics, remoteness and features of access roads. Based on these criteria, after the specialist’s visit, the total area, volume and preliminary cost of the work are determined.

2. Development of the territory, excavation work

Preparing the area for installing an asphalt surface begins with removing the top layer of soil. Typically, bulldozers and loaders are used to remove large layers of soil. Graders are used to level the base surface. At the given marks, a road “trough” is formed with its further compaction.

If there is an old coating on the asphalted area, it is destroyed with a road milling machine. If properly recycled, old coating can be reused.

3. Preparing the base

Now comes the turn of the “road cushion” formation. To do this, two layers of road “pie” are poured: first, sand or a sand-gravel mixture is laid, and to give the entire coating special strength, crushed stone of a large fraction is poured on top, and then a small fraction to minimize voids. Each base layer is leveled with a grader and thoroughly compacted. Edge stones are installed along the edges of the site. To ensure high-quality asphalt paving, before laying the asphalt, the surface of the site is spilled with bitumen.

4. Laying asphalt

The finishing layer consists of asphalt concrete. This material is delivered by dump trucks or prepared directly at the road construction site. The standard composition of ABS includes: mineral powder, sand, crushed stone and liquid bitumen.

The mixture is distributed evenly over the given area. Asphalt pavers are used to lay the final layer of the mixture. Asphalt rolling is carried out with several rollers for the best consistent compaction. Our company has formed its own material base - a modern fleet of special equipment, which numbers about 40 units of equipment, fully covering the entire process of road construction.

It should be noted that the technology for laying asphalt concrete and the materials used may have some differences depending on further operating conditions. For example, to extend the life of highways, new technologies are used - modified gelled petroleum bitumen (MAC bitumen).

Road time

It should be noted that asphalt paving is a seasonal job and directly depends on weather conditions. It is recommended to carry out all work in dry weather.

In autumn and spring, the temperature should not be less than +5 degrees. After all, the delivered mixture is a hot product. Therefore, all manipulations with it must occur as quickly as possible so that it does not have time to cool down. Otherwise, it will be impossible to lay asphalt.

Service life

The service life of asphalt pavement directly depends on loads, traffic intensity, weather conditions, compliance with laying technologies and the quality of the materials used.

The guaranteed service life is approximately 7 - 10 years. But you also need to take into account the fact that with intensive use, the specified period can be reduced. Timely repairs of the road surface, which include the elimination of holes, subsidence, cracks and irregularities, will help extend the service life.

Asphalting today is the simplest, fastest and most economical way to build roads and carry out repair work. To produce new asphalt, asphalt crumbs formed during dismantling are used.

Requirements for asphalting roads

Asphalting of roads must be carried out in strict accordance with all technical requirements set forth in the design documentation. All actions performed by workers must comply with the documentation, otherwise there is a risk of violating the technology and obtaining a poor-quality result.

Asphalt must be laid at an air temperature of at least +5 degrees in autumn and +10 degrees in spring. Asphalting cannot be done in rain, snow or other precipitation. It is necessary to carefully dismantle the old asphalt pavement before laying the new one. Only if all requirements are met can a high-quality result be guaranteed. BIK specialists always comply with all technical requirements, which ensures high quality of road work.

What determines the shelf life

The service life of asphalt pavement depends primarily on adherence to technology during its installation and the use of high-quality materials. The guaranteed service life of asphalt is about ten years. However, during operation under the influence of natural and man-made factors, this period may decrease. Under bad weather conditions and intensive use of the road surface, the service life of asphalt can be reduced to five years, even if all technical requirements for its laying are carefully observed.

How to extend service life

Timely repairs and elimination of potholes, irregularities and cracks as they appear can extend the life of the road surface. Repair work does not require large financial and time expenditures, unlike laying new asphalt.

High-quality asphalting of roads from the company "BiK"

Our company's employees have extensive experience in road work. We always have a wide selection of all the necessary special equipment available, which allows us to perform any work at a high level of quality. Therefore, we offer our Customers a large selection of road work: paving roads, repair work, major repairs, dismantling old asphalt pavement, laying paving slabs and other activities.

www.bik-stroy.ru

Asphalt pavement in modern construction remains the most reliable and in demand. The service life of the canvas is at least 7 years if the rules of installation and operation are observed. The evenness of the finished asphalt, the relative cheapness of the coating and a long service life are the main differences from other types of road construction.

Types of asphalt

Hot asphalt mixture consists of sand, bitumen, gravel, and mineral additives. The composition is prepared from ingredients taken in a certain proportion, heated to a temperature of 120 ° C. Asphalt should be used within 4 hours from the moment of production. Raw materials are transported in special containers to ensure a constant temperature. Asphalt laying is carried out using heavy equipment: pavers, rollers and vibrating plates. The ambient temperature is allowed to be no lower than 5° C when working on asphalt laying. In hot weather, the asphalt road surface may collapse if the road maintenance rules are violated. You can fully use the asphalt-covered strip 6 hours after installation.

Hot mix asphalt

Cold asphalt uses liquid bitumen and a number of special additives to give the product strength. The road can be used almost immediately after laying. For compaction, hand tools are used along with special equipment. High quality is maintained when working in temperatures from -20° C to +40° C. Many customers are stopped by the fairly high cost of the product with the same quality indicators as hot asphalt.

Cold mix asphalt

Asphalt chips - a removed and crushed layer of old pavement - are used mainly for patching roads.

Asphalt crumbs

Laying asphalt

To properly lay the asphalt road surface, ensuring the proper quality of the future road, you must:

mark the area for asphalt paving: determine the boundaries;
designate a place for water drainage after natural precipitation;
bypass underground communications so that in case of repair they do not destroy the road surface; remove roots of large trees;
determine the intended purpose of the asphalt pavement in order to correctly calculate the pit depth and material consumption;
provide construction with special equipment or devices;
calculate the required slope of the road to ensure the flow of rainwater into the drainage system.

Technology for laying asphalt pavement:

remove the top layer of soil using an excavator or similar equipment. The depth of the pit is calculated depending on the purpose of the road;
limit the width of the pavement to ensure decent quality of the road strip;
fill the pit and compact it first with crushed stone measuring 40-60 mm, and then with a fraction of 20-40 mm. You can use broken bricks, stones or concrete slabs;
A layer of river sand is poured on top and carefully compacted. For better settlement, the layers can be moistened;
the final stage is laying the asphalt itself in a layer corresponding to the intended use of the road.

Each layer is compacted separately to ensure decent quality and durability of the finished coating.

kayrosblog.ru

Guaranteed service life of the road surface

A bill establishing a guaranteed service life was submitted to the State Duma. If it is adopted, companies involved in the construction or repair of roads will have to restore the surface at their own expense in the event of destruction of the roadway before the expiration of the warranty period.

In this case, the duration of the guarantee will be established by regulations. So the bottom layer of coating should last at least five years, the base - at least seven years. For earthen pavement, the service life will be 10 years or more, and asphalt pavement will have to be expected to last at least 4 years. The transitional and inferior type of topcoat should last at least 3 years.

In addition, the warranty on bridges, overpasses and various overpasses will be over 8 years, barrier fences will last more than 5 years, and signal posts will become unusable only after 4 years. Road signs will remain in place without replacement for 3 years. Road markings must last at least 9-15 months, with the exception of temporary markings. The warranty period begins to apply from the date of delivery of the work. If a defect is discovered, the warranty period will begin from the moment it is eliminated.

Currently, quality requirements and guarantees are specified in the documentation when concluding a contract. It is expected that in this way builders will be more responsible in their work and will provide the appropriate quality of services to meet the requirements. The rate of deterioration of roads in Russia today shows that most contractors are negligent in their obligations for the construction or repair of roads or various structures, so the government decided to legislate the responsibility of road services Source: jcnews.ru

carddefence.ru

Asphalt laying technology

The work performed at a professional level will not only create a reliable and stable road surface, but will also ensure its long-term service life. START CITY GROUP specialists will help you choose the best base and material for laying asphalt, based on your wishes.

Characteristic

Today, asphalt concrete mixtures, depending on the mineral component, are divided into:

Sandy;
Crushed stone;
Gravel.

The structure of each type has its own characteristics, which determine the effectiveness of using the selected material.

Also, asphalt concrete mixtures are classified depending on the size of the mineral grains:

Fine-grained - less than 2 cm;
Coarse-grained – up to 4 cm.
Sandy – up to 1 cm.

The amount of solid filler contained in the mixture determines which group the asphalt concrete belongs to. There are 3 groups: A, B, C.

Laying technology. Stages. Materials

Today, two road construction technologies are used:

hot paving;
cold asphalting.

Each of them has its pros and cons:

Hot asphalting. The mixture is prepared from viscous and liquid petroleum bitumen. Laying can be done in winter. The temperature of the mixture should not be less than 120 degrees. Before laying the asphalt, the piece of road on which the asphalt concrete mixture will be applied is dried using special equipment.
Cold asphalting. The mixture is prepared from liquid petroleum road bitumen. Laying work is carried out only in the warm season, since water is not dried using this technology. Cold asphalt paving is often used for pothole repair.

Professional paving work requires significant financial investments. After all, for this it is necessary to attract special equipment and experienced qualified specialists.

Laying asphalt consists of several stages:

1. Development of design and estimate documentation

2. Development of the territory, excavation work

If there is an old coating on the asphalted area, it is destroyed with a road milling machine. If properly recycled, old coating can be reused.

3. Preparing the base

4. Laying asphalt

Road time

It should be noted that asphalt paving is a seasonal job and directly depends on weather conditions. It is recommended to carry out all work in dry weather.

Service life

The service life of asphalt pavement directly depends on loads, traffic intensity, weather conditions, compliance with laying technologies and the quality of the materials used.

start-city.com

Destruction of asphalt concrete pavement: causes and types

It is always convenient to drive a car on a flat and smooth highway, developing high speed. It is not uncommon for the quality of the track to not allow this, since the surface deviates from the norm and is unsuitable for high-quality driving. Over time, under the pressure of the wheels of vehicles, especially large trucks, and the influence of unfavorable natural conditions in the form of rain, hail, sudden changes in temperature, the asphalt concrete flooring loses its original appearance. It becomes covered with small cracks, pits, and potholes, which shortens the time for high-quality operation of the highway. Driving on such worn roads leads to damage to vehicles and can even lead to an accident.

Causes of destruction

As a result of the use of asphalt concrete coatings, they are subject to various deformations. Road wear occurs due to external and internal impacts on asphalt concrete pavements. Coating defects caused by external factors include:

force loads from car wheels;
precipitation (rain, temperature changes, thawing, snow, freezing).

The main causes of destruction are non-compliance with the technology for laying or repairing the roadway and the impact of cars.

Internal factors associated with the destruction of asphalt concrete pavement arise due to incorrect design of roads, their construction and repair:

Improper design of an asphalt concrete highway leads to the destruction of the road surface. Inaccurately conducted research, calculations and errors made in determining the intensity of vehicle flow can contribute to the formation of defects on the road made of asphalt concrete and lead to the destruction of the road structure, namely: the integrity of the asphalt layer on road surfaces will be compromised; the foundation soil will subside; the strength of the soil cushion will decrease; wear of the asphalt concrete flooring will follow.
Old techniques were used and low quality materials were selected when working with asphalt concrete pavement. More recently, for installation, laying asphalt mortar and repairing highways, hot asphalt concrete mixtures were used, which included low-quality bitumen. It caused damage to the road deck and deteriorated the strength characteristics of the finished mixture for paving the road surface. However, construction does not stand still, and today the latest polymer-bitumen materials are being developed and implemented, which can significantly improve the properties of the material and the future route. Various additives to the mixture have become very popular to: improve adhesion, increase resistance to water and cracking. Thanks to these additives, the road surface is resistant to sub-zero temperatures. To avoid defects and wear of the road surface, you should not only use new mixtures for laying asphalt, but also choose new technologies that will stabilize and strengthen weakened mobile soils of the base. To prevent the destruction of pavements, a reinforcing mesh is used, which will strengthen the road structure and increase the service life of the asphalt pavement.
Defects and wear on asphalt concrete pavements arise due to incorrect technological processes during the construction of road structures. Damage occurs due to mistakes made during asphalt laying and road repairs. Violations of the rules for transporting asphalt concrete solution contribute to the occurrence of defects, as a result of which the mixture is supplied at the wrong temperature. When compacting the laid mixture, air bubbles were not removed or, conversely, the solution was too compacted, then the asphalt surface will begin to crack and delaminate. Destruction of the route can occur as a result of poor-quality preparation of the roadbed and work on laying the road structure.
Defects on the road surface most often form as a result of weather conditions, when during rains moisture penetrates into the asphalt surface, and the hot rays of the sun spoil the top layer of the road - the strength of asphalt concrete deteriorates, which leads to the formation of potholes. During periods of sub-zero temperatures, the accumulated moisture in the layers of asphalt concrete can increase in volume and thereby destroy the structure and compaction of the asphalt.
As a result of heavy loads from vehicles, the road surface is destroyed. High loads on the highway surface are due to the intense flow of vehicles, as a result of which the 24-hour throughput rate is exceeded and, as a consequence, the service life of the highway surface is reduced. An increase in axial load due to the operation of the road surface by vehicles with a large carrying capacity leads to destruction of the asphalt concrete surface, the formation of ruts and cracks.

Damage to asphalt concrete road surfaces can occur due to the complex influence of external and internal factors.

Return to contents

Main types of defects

Typical defects of highways.

Asphalt concrete damage is of the following types:

Break. It consists of slots in the asphalt area where the flow of vehicles passes. If cracks are not patched in time, they can increase in size and turn into a large-diameter breach.
Expiration of service life. Destructions associated with prolonged use of the road surface, which has not been repaired, affect the thickness of the asphalt concrete layer.
Reducing the strength of asphalt concrete. As a result of heavy loads from heavy trucks, subsidence of the canvas occurs and destruction of the top layer of the coating in the form of unevenness, potholes and ruts.
Potholes. Destructions in the form of potholes are depressions with a sharp break in the edge, which occur due to improper laying of asphalt concrete using low-quality materials.
Peeling. The formation of peeling on the road surface due to the separation of coating particles from the top layer. Formed due to constant variable effects of frost and thaw on the road surface.
Climate impacts. During the period of melting snow masses, a large amount of liquid is formed, which can destroy the road surface, which entails a decrease in the strength characteristics of asphalt concrete.
Chipping. This type of damage occurs as a result of improper laying or repair of the roadway, namely work in precipitation or sub-zero temperatures.
Cracks. Cracks form on the road surface as a result of a sharp change in temperature.
Drawdown. Subsidence occurs due to poor quality materials chosen for laying the roadbed, as well as as a result of insufficient compaction of the asphalt mixture or soil.

Return to contents

How to prevent road damage?

The measures taken will prevent further destruction of the road.

Preventing destruction of asphalt concrete pavements includes comprehensive measures to eliminate problem areas of the route. Timely detection of damage will prevent further formation of potholes and fractures and improve the strength characteristics of the asphalt pavement.

Damage control methods help maintain the desired transport and operational parameters of the route, preserve the integrity of the structure and coating, and also increase the service life of the automotive surface. These methods include:

Using the latest materials, equipment and technology for laying asphalt on highways. Polymer mixtures are used, which are added to the solution at the stage of its manufacture, which are necessary to increase heat resistance in the hot season, when the coating is exposed to direct sunlight and high temperatures. Polymers in the asphalt mixture reduce the formation of cracks during low air temperatures and prevent the formation of potholes during the use of the route.
In the process of constructing a road surface, you must adhere to all the rules and requirements for installing a highway: thoroughly compact the soil and asphalt mixture, add a binder component - bitumen - to the solution in the required proportions to ensure the necessary adhesion and improve the roughness of the coating.
To avoid road damage, it is important to carry out repairs not only when necessary, but also for preventive purposes. Failure to carry out work in a timely manner worsens the condition of the road surface and leads to increased costs for bringing automobile pavements to a standard condition. Delayed repair of the road surface leads to the use of more reinforced thick layers of road surface and higher costs for repairing the road surface.

Return to contents

Conclusion

People encounter asphalt concrete road surfaces every day, so this part of the road structure must not only have high strength and quality, but also be easy to use. Various potholes, cracks, ruts and other damage to the road that can cause a lot of trouble for both pedestrians and vehicles.

To prevent the road surface from deteriorating, it is important to follow technological methods and recommendations for its installation, carry out repair work in a timely manner and not allow existing damage to increase.

kladembeton.ru

Laying asphalt according to SNIP and GOST

Types of asphalt pavement

Types of asphalt:

First class coatings. They are used for laying routes and can withstand heavy loads. The technology involves the use of mineral filler up to four centimeters in size. Such coatings can withstand the weight of loaded vehicles and intensive use.
Second class coatings. They are used for paving squares, sidewalks and pedestrian roads. The largest inclusions of the asphalt mixture reach 25 mm.
Third class coatings. The priority in this case will be the plasticity of the mixture. Mineral particles of minimal size (up to 15 mm), which allows for a tight fit of the composition. This type of coating is used for non-vehicular use (private courtyards, institutional areas, sports grounds).

Application technologies:

Hot asphalt. Its installation technology requires the use of special equipment, as well as compliance with a number of conditions. First of all, this is the temperature of the finished mixture and the ambient air. It is unacceptable to lay cooled asphalt, or to carry out work at sub-zero temperatures. The second important point is the speed of laying hot asphalt. If the work is not performed in accordance with GOST, the quality of the coating will be poor. Hot asphalt is used to lay new roads and sidewalks. After application, the coating should not be used for some time to ensure sufficient adhesion.
Cold asphalt. Its standards are also regulated by GOST and SNIP, but in production other grades of bitumen are used, which harden faster and do not require a certain temperature. Cold asphalt can be laid in a wider range of ambient temperatures (up to - 5ºC is allowed). Most often, this method is used when performing pothole repairs of roads, or to perform asphalt paving on your own.

Preparatory work before laying asphalt

How to prepare the surface:

Clear and mark the asphalt paving area. If necessary (swampy areas, possible problems with the soil), geodetic surveys are carried out.
The top layer of soil is completely removed. For highways it is possible to build a special embankment, but for a pedestrian road made of asphalt this is not required.
A sand “cushion” is poured into the bottom of the trench, after which it is necessary to install a special material - geotextiles. It will prevent the displacement of large fractions of building materials into the sand.
It is necessary to fill the resulting pit with crushed stone of different sizes. The fraction of the material will depend on the purpose of the coating. The largest crushed stone is used for laying highways. The layers are arranged in descending order from coarse to fine-grained materials.
The number of preparatory layers also depends on the further use of the road. After installation, the material is well pressed with a special roller. This will ensure reliable coupling, eliminating possible operational problems.
To strengthen and prevent cracks from appearing on the finished coating, a reinforcing mesh is used.

How is asphalt paving done?

Basic requirements of the standards:

Immediately before laying asphalt, heated bitumen or bitumen emulsion is applied to the prepared surface.
Laying hot asphalt should be carried out exclusively at positive air temperatures (not lower than 5 degrees).
The mixture must be at a certain temperature, so before application it is kept hot (not lower than 100 degrees).
The thickness of the asphalt mixture layer is determined by the purpose of the coating. Asphalt is applied in sections of a certain length, after which it is leveled and compacted.
Compaction of the layer must begin immediately after backfilling. For this purpose, special equipment is used - a roller, a brick press or an asphalt paver.
The applied layer should harden for at least a day, but for cold asphalt this time can be only a couple of hours.

Final works

After asphalting, a special impregnation must be applied to the section of the future road. It provides tight adhesion to asphalt and gives the coating an attractive appearance.

The following impregnation options are distinguished:

Asphalt emulsion. Among all types, this is the most affordable mixture, but does not always live up to expectations. Most often used for sections of road without heavy traffic or sidewalks.
Coal tar. A reliable base, which also gives the finished coating an aesthetic appeal. It is not affected by petroleum products and has a long service life.
Acrylic polymers. Adding special components to the mixture allows you to obtain an elastic and durable coating. It is even possible to change the color, which is used for additional decoration of the area.

nsk-asfalt.ru

Assessment of fatigue life of asphalt concrete pavements under real operating conditions

In the conditions of modern high-speed intensive traffic, asphalt concrete pavements are exposed to multi-cyclic effects of vehicles, which is dynamic in nature and is one of the main factors in reducing the transport and operational condition of road pavements and their destruction. It is known that the destruction of asphalt concrete under the influence of repeated loads is caused by fatigue processes, i.e. the formation and accumulation of microdefects with a gradual decrease in strength over time.

The works of Sall A.O., Radovsky B.S., Rudensky A.V., Bakhrakh G.S. are devoted to the study of fatigue durability of asphalt concrete pavements. etc. The increased interest in the issues of fatigue failure of road surfaces is explained by the increasing traffic flow every year, on the one hand, and the decrease in the actual service life of asphalt concrete pavements, on the other hand. That is why, in a number of foreign methods for designing road pavements, fatigue calculations of the material of the bending layer are considered the main thing in determining the required thickness of the layers of the structure (the Shell oil company method, Finnish design standards, etc.). An important conclusion was obtained during the development of the “Guide to the Mechanical-Empirical Design of New and Reconstructed Pavements” (USA), in which much attention is paid to the issues of fatigue cracking (two types of fatigue cracking are considered: ascending and descending). It consists in the fact that asphalt concrete pavements with a thickness of 7.6 - 12.7 cm (3-5 inches) are subject to the greatest fatigue failure. Increasing or decreasing the thickness of the asphalt concrete pavement leads to an increase in its fatigue life. Considering that in the Russian Federation on roads of III and IV technical categories the thickness of a two-layer asphalt concrete pavement is 10-12 cm, increased attention should be paid to the development of measures to increase the resistance of asphalt concrete to fatigue failure.

The method used in our country for calculating the strength of flexible road pavements involves assigning the thicknesses of individual structural layers based on the calculation of the structure as a whole based on the permissible elastic deflection with checking the resistance of monolithic layers to fatigue failure from stretching during bending and the shear resistance of soils of low-cohesion structural layers. At the same time, the calculation of the structure for the resistance of monolithic layers to fatigue failure, in our opinion, has a number of disadvantages: – discrepancy between the period of the year during which the number of applications of the design load is summed up and the design parameters of the asphalt concrete layers. So, for example, for the region of the European part south of the Rostov-on-Don-Elista-Astrakhan line, according to Table. P.6.1. ODN 218.046-01 the number of calculation days per year is 205, which covers a period with various temperature and humidity factors. In this case, the calculated values of the elastic modulus of asphalt concrete during the calculation of tensile stresses in the lower layer of asphalt concrete correspond to low spring temperatures; the calculated total number of applications of the design load during the service life is determined taking into account the number of design days per year, which does not correspond to the real conditions for the occurrence of fatigue phenomena in asphalt concrete pavements, because according to clause 6.1. ODN 218.046-01 “the design day is considered to be the day during which the combination of the condition of the subgrade soil in terms of humidity and temperature of the asphalt concrete layers of the structure provides the possibility of accumulation of residual deformation in the subgrade soil or poorly cohesive layers of road pavement,” and fatigue damage accumulates throughout the entire period operation;

the values of tensile stresses that arise in the asphalt concrete layer during the passage of vehicles change throughout the year depending on the temperature regime of the coating and the soil moisture of the subgrade. This means that when calculating asphalt concrete layers for resistance to fatigue failure, it is necessary to take into account the climatic factors of the region, and in the current regulatory document, the calculated values of the elastic modulus of asphalt concrete are assumed to be the same for all road climatic zones.

Along with the stated shortcomings, it should be noted that the current regulatory document on the design of flexible road pavements is limited in the field of their design. Traditional design methods provide for the arrangement of layers with a decrease in the strength characteristics of the material in depth. In this case, porous or highly porous asphalt concrete, which has the least resistance to fatigue failure, is laid in the lower layer of the coating. It is not possible to design road pavement whose bottom layer has a higher elastic modulus, since for such a design it is impossible to calculate the permissible elastic deflection in accordance with ODN 218.046-01. More than 25 years ago A.O. Sallem, B.S. Radovsky and others proposed structures that are resistant to fatigue failure, in which the elastic modulus of the lowest layer of asphalt concrete is greater than that of the layer located above it. In 2000, a similar principle was followed in the design of pavement in Southern California on a high-traffic highway. At the suggestion of a group of specialists from the University of California, led by K. Monismith, the following road pavement structure was built: a wear layer of a highly porous drainage mixture (25 mm), a coating (75 mm) of a dense asphalt concrete mixture with a polymer bitumen binder, an intermediate layer (150 mm) of a dense mixture on high-viscosity bitumen, a lower layer of asphalt concrete (75 mm) with the same grain composition and bitumen as the intermediate one, but with a higher bitumen content.

The coating and intermediate layer were chosen to ensure minimal rutting in the hot season, and a dense bottom layer with a high bitumen content should provide high resistance to bending fatigue. Research and experience in operating highways show that increasing the thickness of the structural layers of road pavement ( especially non-cohesive foundations) under conditions of intense high-speed traffic does not provide the required service life of road structures, although it increases their overall modulus of elasticity. To increase the durability of road structures, it is necessary to search for new effective design solutions and test them.

Our country has accumulated significant experience in materials science solutions to increase the fatigue life of asphalt concrete pavements: reducing the porosity of asphalt concrete, increasing the viscosity of bitumen, introducing modifying, strengthening additives (polymer, reinforcing, etc.), and using reinforcing layers. However, the absence in Russian standards of methods and requirements for the fatigue strength of asphalt concrete mixtures under repeated loading excludes the possibility of targeted selection of compositions of asphalt concrete mixtures with increased fatigue strength, which sometimes leads to erroneous decisions when choosing the type of mixtures and justifying the feasibility of using polymer and reinforcing additives.

In modern conditions of high-speed intensive traffic of vehicles, in order to objectively assess the durability of materials of structural layers of road pavement, it is necessary to switch to new methods of testing them, corresponding in terms of loading conditions to the real impact of traffic flow. Such test methods are currently carried out in many countries. According to the draft European standards (prEN 12697-24), for example, the determination of fatigue strength is carried out at loading frequencies of 10 Hz, 25 Hz, and also in the frequency range from 1 to 60 Hz.

Thus, the solution to the problem of increasing the fatigue life of asphalt concrete pavements should be comprehensive and integrated, including: at the design stage of flexible road pavements, calculation of the fatigue life of asphalt concrete pavements, taking into account loading characteristics under given climatic conditions in different periods of the year; analysis of the effectiveness of design solutions to increase the fatigue life of asphalt concrete coatings; testing the fatigue strength of asphalt concrete mixtures under repeated loading to select compositions that provide the specified operational properties of asphalt concrete; at the stage of operation of highways, calculating the characteristics of the dynamic impact of vehicles taking into account the actual smoothness of road surfaces; calculating the fatigue life of operating asphalt concrete pavements and predicting the residual life of road surfaces taking into account real loading; testing the fatigue strength of asphalt concrete selected from the coating. To assess the fatigue life (residual life) of asphalt concrete pavements, we have developed a comprehensive experimental - theoretical method. Its essence is as follows:

– at the first stage, the dynamic characteristics of loading of asphalt concrete pavements on a given highway are calculated throughout the year. The operational level of the road surface and speed modes determine the level and frequency characteristics of the dynamic impact of vehicles. Calculation of the dynamic loading characteristics of the road surface is carried out using developed mathematical models of the “road structure - soil” system for a given composition of the traffic flow. This takes into account seasonal changes in climatic factors characteristic of a given region. This method (calculation and theoretical) can be implemented both in the design of new road structures to substantiate the most efficient and durable asphalt concrete pavements, and in the operation of highways to calculate the residual life of road pavements under the real dynamic impact of traffic flow. For operating highways, it is advisable to use an experimental method in which the dynamic loading characteristics of an asphalt concrete pavement are determined during field measurements using a vibration-measuring complex;

– at the second stage, the durability of asphalt concrete pavements is calculated under operational loading conditions. Currently, DorTransNII RGSU has developed a laboratory installation for testing asphalt concrete for fatigue failure under dynamic (vibration) influence in a wide frequency range (from 0.5 to 100 Hz). The loading mode during laboratory tests is adopted in accordance with the previously calculated loading characteristics of the asphalt concrete pavement. Fatigue failure curves for various types of asphalt concrete mixtures allow you to select the type of mixture, select the composition and justify the feasibility of using polymer and reinforcing additives to increase the durability of the road surface. Tests for fatigue failure of asphalt concrete from the surface of operating highways under real loading conditions make it possible to predict the residual life of asphalt concrete pavements and to reasonably prescribe the types and timing of repair work.

Conclusion

In the conditions of modern high-speed intensive traffic, the impact of vehicles on the road structure has a significantly pronounced dynamic nature, which leads to an increase in loads on road structures and a decrease in the fatigue life of asphalt concrete pavements.

The calculation of road pavements used in our country for the resistance of monolithic layers to fatigue failure has a number of disadvantages, which does not allow optimal decisions to be made at the road pavement design stage to increase the fatigue life of asphalt concrete pavements.

To increase the durability of road structures, it is necessary to search and test new effective design solutions, which include, for example, the construction of lower layers of asphalt concrete pavements from dense mixtures with a high bitumen content, providing high resistance to bending fatigue; installation of reinforcing layers, etc. The absence in Russian standards of methods and requirements for the fatigue strength of asphalt concrete mixtures under repeated loading excludes the possibility of targeted selection of compositions of asphalt concrete mixtures with increased fatigue strength, which sometimes leads to erroneous decisions when choosing the type of mixtures, justifying the feasibility of using polymer and reinforcing additives . To objectively assess the durability of materials of structural layers of road pavement, it is necessary to switch to new methods of testing them, corresponding in terms of loading conditions to the real dynamic impact of traffic flow. The dynamic impact of traffic flow on a road structure is determined by the smoothness of the road surface and speed conditions. It is proposed to calculate the dynamic loading characteristics of the road surface based on the developed model of the “car-road” system for a given composition of the traffic flow, or to determine them during experimental measurements using the vibration measuring complex DorTransNII RGSU.

6. To assess the residual life (fatigue life) of asphalt concrete pavements, taking into account real dynamic loading, a comprehensive experimental-theoretical method has been developed and proposed, based on the developed mathematical model of the stress-strain state of the “road structure - soil” system and experimental tests of fatigue failure of asphalt concrete under real loading conditions.

Literature Radovsky B.S., Merzlikin A.E. “Guide to the mechanical-empirical design of new and reconstructed road pavements” (USA) // Science and technology in the road industry. 2005, No. 1, pp. 32 – 33. ODN 218.046 – 01. Design of flexible road pavements. -M., 2001. – 146 pp. Sall A.O. On the issue of designing road pavements with asphalt concrete bases / Tr. Soyuzdornii, vol. 105. M, 1979, p. 142 – 155. Rudensky A.V. Road asphalt concrete pavements. – M.: Transport, 1992. – 253 pp. Iliopolov S.K., Seleznev M.G., Uglova E.V. Dynamics of road structures. - Rostov-on-Don: Publishing House "South". 2002 – 260 pp. Iliopolov S. Investigation of dynamic transport impact in pavement design/ IX International Conference. Kielce. 2003, pp. 451 – 457 Frequency characteristics of various types of vehicles Roughness of the road surface (micro-profile) Average speed modes of vehicles Calculation of the dynamic impact of vehicles on a highway (vehicle-road model) 1st stage Road structure Amplitude-frequency characteristics of the impact of various vehicles Composition of traffic flow Calculation of characteristics dynamic stress-strain state of asphalt concrete pavement (model “road structure - soil”) Seasonal changes in climatic factors Calculation of the dynamic loading characteristics of asphalt concrete pavement throughout the year Testing of asphalt concrete samples for resistance to fatigue failure under a given loading mode Stage II Service life (residual life) of asphalt concrete pavement Assessment of fatigue life (residual life) of asphalt concrete coatings

Asphalt service life. Road works technologies

Types of asphalt pavement

Types of asphalt:

Application technologies:

Preparatory work before laying asphalt

How to prepare the surface:

How is asphalt paving done?

Basic requirements of the standards:

Final works

The following impregnation options are distinguished:

Preface

1 area of ​​use

2 Normative references

3 Terms and definitions

4 Classification

5 Technical requirements

6 Safety and environmental requirements

7 Acceptance rules

8 Test methods

9 Transportation and storage

10 Directions for use

Appendix A (recommended). Physico-mechanical characteristics of crushed stone used for the construction of a rough surface of the upper layers of hot cast asphalt concrete road pavement using the hot embedding method

Appendix B (recommended). Complete passages of mineral material using square sieves

Appendix B (recommended). Requirements for the granulometric composition of the mineral part of all types of mixtures

Characteristic

Laying technology. Stages. Materials

1. Development of design and estimate documentation

2. Development of the territory, excavation work

3. Preparing the base

4. Laying asphalt

Road time

Service life

Requirements for asphalting roads

What determines the shelf life

How to extend service life

High-quality asphalting of roads from the company "BiK"

Types of asphalt

Laying asphalt

Technology for laying asphalt pavement:

Guaranteed service life of the road surface

Asphalt laying technology

Characteristic

Laying technology. Stages. Materials

1. Development of design and estimate documentation

2. Development of the territory, excavation work

3. Preparing the base

4. Laying asphalt

Road time

Service life

Destruction of asphalt concrete pavement: causes and types

Causes of destruction

Main types of defects

How to prevent road damage?

Conclusion

Laying asphalt according to SNIP and GOST

Types of asphalt pavement

Types of asphalt:

Application technologies:

Preparatory work before laying asphalt

How to prepare the surface:

How is asphalt paving done?

Basic requirements of the standards:

Final works

The following impregnation options are distinguished:

Assessment of fatigue life of asphalt concrete pavements under real operating conditions

1 area of use