Asphalt is a reasonably strong and reliable road surface, but it can last much longer than you think if you follow the simple steps. They will help keep the asphalt intact, prevent cracks and failures, and reduce the cost of restoration and future road repairs.
Immediately after the repair of the road in the yard has been made, it is recommended to refrain for several days from cycling along it, and even more so from other vehicles. Motorists who are accustomed to leaving their cars near the entrances in the territories of the HOA should understand that how soon they will have to raise funds for new repairs depends on their vigilance, because it is the load from the cars that causes a strong weakening and destruction of the asphalt. Experts advise not to ride a bicycle or motorcycle around the yard for at least three days after laying the asphalt and not to drive a car for a week. This "rest" period is very useful for asphalt. It will be able to harden as much as possible only six months after laying. But since it will not be possible to restrict the movement of vehicles in the courtyard for such a period, then at least the first three days you need to let the asphalt stand without load. This will extend its "life".
If the movement of heavy vehicles cannot be ruled out, for example, the daily passage of a garbage truck, then thick plywood sheets can be laid on the asphalt.
To maximize the lifespan of your new asphalt pavement, you can monitor its condition and protect it from the effects of the weather. For example, in case of heavy rainfall and the absence of properly equipped drains, you can deal with the elimination of puddles using ordinary brooms. Residents of the HOA from each entrance could do such work near each entrance, as a result of which the yard will be put in order quickly, and the asphalt will not be damaged by water. In winter, of course, snow removal is a necessary and useful measure to extend the life of the asphalt.
Snowblowers are not in great demand today for clearing yards. And the new legislation prohibits the export of snow outside the city limits due to the harm caused in this way to the environment. Therefore, new devices have come into vogue, allowing you to quickly and effectively deal with snowdrifts on the surface of the asphalt: snow melters. These are mobile and very convenient installations, the operation of which is provided by a heating element inside and a container for collecting snow. The device moves with the help of a chassis, and can operate from the electrical network, diesel fuel or hot water. Such snow-melting structures are extremely convenient for use in small yards, alleys, where large equipment cannot be used. The HOA can hold a general meeting at which the owners can decide on the purchase of such an installation. This decision should be made only in the presence of all owners of the HOA. Thus, the durability of the asphalt can be significantly extended and protected from damage that occurs as a result of snow melting in spring and winter with strong temperature changes.
Another tip is addressed to motorists: do not place cars in the same place in the yard, which was paved a few days ago. You need to use either a specially equipped parking lot near the house, or, if this is not possible, park the car in different places, and not in the same place.
It is advisable to closely monitor the appearance of the slightest cracks and holes on the roads. They can get spent fuel, gasoline, oil from cars. These are aggressive compounds that can increase the size of the pit. Therefore, it is better to immediately close up small pits with improvised materials or asphalt crumbs. It is not expensive and will extend the life of the asphalt.
Today many road building companies use special sealants. With their help, asphalt surfaces are processed, which become impervious to moisture. Such sealant compositions are not applied immediately after new asphalt is laid or repaired. It is necessary to wait one or two winter seasons and then apply the sealant. Only after one year, the asphalt becomes extremely compacted and no means can get inside it with a layer, including the sealant, which should remain on the surface of the asphalt, and not penetrate and destroy it.
Thus, homeowners have the opportunity to make their asphalt durable and keep it in top condition with just a little effort.
Asphalt concrete pavement: general information
The first asphalt pavements were built in Babylon 600 years BC. The construction of pavements using bitumen resumed only in the 19th century in Western Europe and then in the USA. The first section of asphalt concrete pavement in Russia was built on Volokolamsk highway in 1928.
Asphalt concrete pavement has a number of positive properties and high transport and operational performance: slow wear under the influence of heavy vehicles; relatively high strength and resistance to climatic factors and water; hygiene (not dusty and easily cleaned of dust and dirt); ease of repair and strengthening of the coating.
Asphalt concrete pavement is laid on roads with a longitudinal slope of up to 60 ppm. The cross slope is prescribed within 15-20 ppm.
Asphalt pavement pavement structures are constantly changing due to the fact that traffic loads and traffic intensity are constantly increasing. As early as 20-30 years ago, two-layer asphalt concrete pavements with a thickness of 10-12 cm on a crushed stone base of 18-25 cm were used on roads of high categories. Now such structures are suitable only for roads of lower (IV and V) categories, and on roads of categories II and I, the structures have become more powerful, at the base, lean (rolling) concrete with a thickness of 20-35 cm is increasingly used, and the total thickness of the laid asphalt is equal to 18-25 cm.
The service life of asphalt concrete pavements depends not only on the quality of the asphalt concrete, but also on the construction of the pavement. An asphalt pavement of the same quality works differently on different substrates. So, in asphalt concrete pavements, laid on bases made of monolithic cement concrete, cracks appear due to the thermophysical incompatibility of the materials of the pavement and the base, that is, seams and cracks in cement concrete bases are repeated in asphalt concrete pavements.
Crushed stone bases are devoid of this drawback, however, they are subject to uneven shrinkage occurring due to the mutual movement of crushed stone grains under the influence of multiple impacts of transport loads.
With regard to the selected pavement structure, it is necessary to select the type of asphalt concrete mixture. Coverings from asphalt concrete mixtures should be arranged in dry weather. Asphalt paving (asphalt paving) should be carried out at an ambient temperature of at least + 5oC. Asphalt paving (asphalt paving) can be done both mechanically, using an asphalt paver, and manually.
Backfilling and restoration of roads to summer cottages and garage cooperatives, roads with inanimate traffic, asphalt road crumbs is a progressive method of road restoration. Due to the low cost and higher resistance to destruction than crushed stone, sand. Asphalt road chips have a higher density, are saturated with bitumen, which serves as an additional binding link and a sealing element, which allows the road to last much longer.
The best material for backfilling roads inside summer cottages and garage communities is asphalt crumb. The advantage of asphalt chips is that they are laid much denser than sand and gravel. A crumb of asphalt, after filling, is rolled by the wheels of cars to such an extent that it looks like asphalt. A road covered with asphalt chips is more resistant to erosion and other damage caused by water. The bitumen present in the crumb serves as an additional binding and sealing element, which allows the road to last much longer than the road dumped from sand and crushed stone.
Backfilling and restoration technology, dirt roads:
Before laying asphalt chips, leveling is carried out, with the help of a motor grader knocking down the unevenness of the road, profiling the base, achieving the necessary evenness. After reaching an even layer of the base, the road crumbs are leveled along the entire road, the slopes are profiled. Achieving evenness of the coating of the same layer thickness. At the final stage, compaction is performed using a road roller, thereby achieving high density and resistance to erosion and other damage caused by water.
After the road roller has compacted the surface, the new road is ready for use.
Before installing the base, it is necessary to install side stones and curbs. The bases for asphalt concrete pavements are made of crushed stone, slag, brick breakage, as well as other waste received from the dismantling of buildings and structures. Crushed old asphalt concrete (asphalt chips) is also used as a base material. The thickness of the base is usually assigned 10-15 cm, depending on the properties of the underlying soils. The base material is leveled with a layer of the required thickness and then compacted with rollers with scattering of stone or slag fines for chipping and splitting.
The thickness of the asphalt concrete pavement is usually taken as 3-4 cm. At the entrances to neighborhoods and yards, the thickness of the asphalt concrete layer is raised to 5 cm or more. Sand or fine-grained asphalt concrete mixtures are used for pavement coverings. For compacting asphalt concrete, vibratory plates or small-class rollers are used.
Sports field asphalting
font-size: 12.0pt; font-family: "times new roman> An asphalt base is being built for a special sports coverage on tennis courts, volleyball, basketball and other sports grounds. The construction of such a base includes a set of works:
- Earthwork (preparation of the "trough"). Excavation and removal of soil to the required height, as a rule, to the height of the crushed stone base. Layout, leveling of the soil inside the trough; Installation of side stones, curbs and drainage systems around the perimeter of the site; Installation of a sandy base with a thickness of 10-20 cm, if the soil contains clay; Arrangement of crushed stone base 15-18 cm thick. From crushed stone fractions 40x70 and 20x40. Can be used instead of rubble fr. 40x70, black crushed stone, and on the top layer - fine asphalt crumbs. It is advisable, to increase the reliability of the crushed stone base, to perform additional splitting by screening. Installation of embedded parts for racks; The top layer is made of a fine-grained asphalt concrete mixture of the “G” type, with a total thickness of 8 cm. The asphalt is laid in two layers of 4 cm each. To drain water from the surface of the court, the base must set a slope of 0.5 - 1 ‰ on the short side; Due to the specificity of the asphalt paving technology, it is impossible to achieve perfect evenness of the base. Therefore, before laying the sports flooring, it is necessary to level the base with special mixtures.
Laying in an embankment and soil compaction are carried out during planning works, erection of various embankments, backfilling of trenches, foundation sinuses, etc. Compaction is carried out in order to increase the bearing capacity of the soil, reduce its compressibility and reduce water permeability. Compaction can be superficial or deep. In both cases, it is carried out by mechanisms.
There is soil compaction by rolling, ramming and vibration. The most preferable is the combined method of compaction, which consists in the simultaneous transfer of various influences to the soil (for example, vibration and rolling), or combining the compaction with another working process (for example, rolling and movement of vehicles, etc.).
To ensure uniform compaction, the dumped soil is leveled with bulldozers or other machines. The greatest compaction of the soil with the least labor input is achieved at a certain moisture content that is optimal for a given soil. Therefore, dry soils should be moistened, and waterlogged soils should be drained.
The soil is compacted in sections (grabs), the dimensions of which should provide a sufficient scope of work. An increase in the work front can lead to drying out of the soil prepared for compaction in hot weather or, conversely, to waterlogging in rainy weather.
The most difficult is the compaction of the soil when backfilling the sinuses of the foundations or trenches, since the work is carried out in cramped conditions. In order to avoid damage to foundations or pipelines, the adjacent soil 0.8 m wide is compacted using vibrating plates, pneumatic and electric rammers in layers 0.15 ... 0.25 m thick.More productive methods, for example self-moving vibrating plates and others, are used when compaction of the backfill under the floors.
The penetrations of soil compactors are made with a slight overlap in order to avoid misses of uncompacted soil. The number of penetrations in one place and the thickness of the layer are set depending on the type of soil and the type of soil compacting machine or are established empirically (usually 6 ... 8 penetrations).
Embankments, which do not have high requirements for soil density, can be compacted by vehicles during the filling process. The scheme of work is drawn up so that the loaded transport moves along the dumped layer of soil.
Unlike conventional concrete, cement-crushed stone mixtures contain significantly less cement and can be compacted by the static effect of self-propelled rollers with smooth drums. The base of lean concrete is arranged along the technological layer of compacted crushed stone, cement soil or sand and gravel mixture 10-15 cm thick. On roads, a single-layer asphalt concrete pavement with a thickness of at least 10 cm is laid on a layer of lean concrete. Lean concrete is laid in the base with a concrete paver, crushed stone paver or with the help of small-scale mechanization. The mixture is spread in a layer up to 20 cm and immediately compacted, first with light and then with heavy rollers until the rolling marks disappear completely.
The device of an asphalt concrete pavement over lean concrete can be carried out after it has been compacted or after 2-3 days. In the latter case, the surface of the base should be treated with a bitumen emulsion in two layers. The total consumption of the emulsion is 0.7 kg per 1 m2 of the base. The installation of lean concrete foundations significantly reduces labor costs, as well as the time to start laying asphalt concrete. In the bases of lean concrete, temperature transverse joints are arranged. The distance between them is taken from 20 to 40 m, depending on the air temperature when laying the concrete mixture, the grade of lean concrete and the type of asphalt concrete pavement. The seams are cut with special cutters or arranged with a bookmark in the base of spruce or pine boards.
Reinforcement of asphalt as a way to increase its durability
The issue of road surface reinforcement is by no means idle, since the bulk of roads and streets are covered with asphalt concrete, and its often deplorable state and rapid, over several years, destruction is familiar to everyone who drives their own or municipal wheels.
The quality of asphalt paving and the service life of asphalt concrete depends both on the quality of the base on which it is laid and on the properties inherent in the very nature of the asphalt concrete pavement.
Asphalt concrete pavements with good resistance to short-term loads, have low tensile strength in bending and insufficient distribution capacity when the load is repeatedly applied. Therefore, the fatigue and reflected cracks arising during the operation of the asphalt concrete pavement, developing intensively, lead to its premature destruction.
For a long time all over the world, the service life of asphalt concrete pavement has been increased by reinforcing it with geogrids. Today on the market there are geonets made of fiberglass, polyester, basalt fibers and a number of others.
Based on the results of numerous laboratory studies and operating experience, the following requirements are imposed on reinforcing geonets:
- the modulus of elasticity of the reinforcing material must be greater than the modulus of elasticity of asphalt concrete in order to absorb tensile forces in the same way as in reinforced concrete; the adhesion between the asphalt and the reinforcing material must be very good in order to distribute the tensile stresses in the reinforcing material into adjacent areas of the asphalt concrete pavement. In doing so, two important factors must be taken into account that affect the strength of this bond: the difference between the coefficients of thermal expansion of asphalt concrete and the reinforcing material should be as small as possible, since with temperature drops, secondary local stresses arise at the point of their junction, which can exceed the limit values, and the system will stop working as a whole. An example is the excellent behavior of reinforced concrete, where steel and concrete have the same coefficients of thermal expansion; the modulus of elasticity of the reinforcement material should not exceed the modulus of elasticity of asphalt concrete by several orders of magnitude. This is due to the fact that, being an elastic-plastic material, asphalt concrete under a transport (dynamic) load behaves like an elastic material, perceives stresses and redistributes the load over a large area of the underlying layers together with the reinforcing material. If too stiff reinforcement is applied, most of the tensile stresses will be taken up by it. These stresses must be transmitted to the asphalt layers through the adhesion forces and a very large area of reinforcement embedding in the asphalt would be required so that the stresses do not exceed the adhesion forces of the reinforcement to the asphalt.
Characteristics of some materials and finished products |
|
Name | Elastic modulus, N / mm2 |
Asphalt | 1000 – 7000 |
Concrete | 20000 – 40000 |
Steel | 200000 – 210000 |
Fiberglass | 69000 |
Polyester fiber | 12000 – 18000 |
Polyester Geogrid Strands | 7300 |
Basalt geogrid strands | 35000 |
Analyzing the above data from the above positions, one can understand why materials such as glass, steel or basalt work in tandem with asphalt concrete worse than polyester.
The difference between the moduli of elasticity of fiberglass, steel, basalt, on the one hand, and asphalt concrete, on the other, causes problems with the adhesion strength between them. Reinforcement with the aforementioned materials would be possible if the reinforcing material extended over the entire width of the carriageway and were sufficiently secured along its edges. Otherwise, the reinforcement will simply be pulled out of the asphalt concrete.
There are examples of the use of fiberglass meshes for reinforcing asphalt concrete with an insufficient length of mesh embedding in asphalt concrete. The permissible adhesion forces between the mesh and the asphalt concrete are exceeded, delamination occurs between the mesh and the asphalt concrete, and under the influence of dynamic traffic loads, relative movements between the mesh and the asphalt appear, which lead to the complete destruction of glass fibers. This was found out during core sampling, when only white powder remained from the fiberglass mesh after several years of operation.
The reinforcement material should not be affected by dynamic loads from moving vehicles, otherwise the reinforcement will not work well in the future. Studies have shown that fiberglass meshes do not withstand dynamic loads. The breaking strength of the tested fiberglass meshes dropped to 20-30% of the initial value after 1000 loading cycles, and none of them withstood 5000 loading cycles, while Hatelit successfully withstood 6000 cycles.
Studies of fiberglass mesh reinforcement have shown disappointing results under various conditions. On two different road sections, the behavior of fiberglass reinforced and unreinforced asphalt concrete was investigated for four years.
In the first section, the fiberglass-reinforced pavement had many more cracks on the roadway than the unreinforced one.
In the second section, the final inspection showed the absence of cracks in the transition zone of both reinforced and unreinforced coatings. At the same time, the fiberglass mesh did not prevent the appearance of cracks in the area of intersection with the old railway tracks.
Thus, based on the research results, it is not recommended to use fiberglass mesh as a crack-breaking reinforcement.
The most serious approach to the choice of asphalt concrete pavement reinforcement should be taken when constructing asphalt concrete runways. After all, potholes in the asphalt on the roadway force drivers to slow down and only sometimes lead to damage to the car's suspension. Violation of the integrity of the asphalt concrete on the runway is a direct path to a disaster with fatalities.
The most optimal choice for reinforcing asphalt concrete in comparison with fiberglass mesh is a reinforcing mesh of the Hatelit type. This type of mesh has quite high technical and economic indicators:
- significant reduction in the thickness of asphalt concrete; increasing its crack resistance by 3 times or more; an increase in the service life of the coating and a decrease in operating costs for its maintenance.
The use of fiberglass reinforcing meshes did not give a positive effect due to their low physical and mechanical characteristics and the inability to effectively prevent the development of cracks in asphalt concrete.
Despite the fact that new types of fiberglass reinforcing nets are constantly being developed, their effectiveness and durability remains significantly lower than that of Hatelit-type polyester nets.
The most effective geogrids are Hatelit C grids according to the following indicators:
- The reinforcing threads of the nets are made of polyester and, in comparison with fiberglass threads, take well not only stresses in the horizontal plane, but also stresses from multiple vertical loads. Polyester yarns are resistant to vertical stress and deformation. Glass threads do not perceive vertical deformations and stresses; already in the factory, the mesh is treated with bitumen, which provides good adhesion to asphalt concrete; is a composite material. In addition to the reinforcing threads, the meshes have a geotextile base, which ensures the design position of the mesh when laying without additional operations; the dimensions of the cell of the reinforcing nets must be equal to the doubled size of the largest fraction of crushed stone. For fine-grained asphalt concrete, the optimal mesh size is 40x40 mm.
It should also be noted that in dynamic bending tests of specimens at maximum tensile stresses equal to 10 MPa, the number of cycles to failure for a specimen with Hatelit C is 13 times higher than that for a specimen with a basalt mesh. With three passes of the compacting roller, the basalt mesh lost almost 50% of its strength (Hatelit C - 10%), and with 5 passes - 60% (Hatelit C - 13%). Thus, there is an obvious tendency for the basalt mesh to lose its strength, to reduce the ability to deform and break with an increase in the number of compaction cycles or simply passages of heavy vehicles during road works. For comparison, in Hatelit C, the mechanical damage coefficient, even with a 5-fold compaction, remained within the permissible range - it did not exceed 1.15.
Shear stability studies showed that for the core with Hatelit C it is equal to 34 kN / m (due to good bitumen impregnation, fusion and compaction of the nonwoven material applied to the mesh), and for the core with basalt mesh, the shear resistance was 6 kN / m with the minimum allowable value 15 kN / m.
In addition, the consumption of 70% bitumen emulsion when laying the Hatelit S mesh is 0.3–0.5 l / m. sq., and when laying a grid of basalt - 1.0-1.2 l / m2. sq.
In the end, it should be noted that the Hatelit C geogrid is certified in Russia and Ukraine. In addition, in Ukraine there is a “Technological regulation for the use of the Hatelit 40/17 C mesh for reinforcing asphalt concrete”.
Reinforcement of the road: | Geogrid Hatelit C in rolls: |
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Geogrid Hatelit 40/17 С: | Laying asphalt on top of the Hatelit 40/17 C geogrid: |
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If you get to the dacha by your own car, then sooner or later you will get tired of putting it just near the porch of the house. You will think about the time to build a stationary parking lot for your "iron horse", which will protect it from hot sunlight and atmospheric precipitation during your summer vacation. The easiest and fastest to perform is a parking lot in the country in the form of a platform with a shed. Let's talk about how to build such a parking lot and select materials for it.
Choosing a parking location
The place to "rest" your car should be located on level ground. The slope is absolutely not suitable for parking, since you will subsequently have to constantly put the car on the hand brake, lay stones or bricks under the wheels, and just be nervous that the car, despite your efforts, will leave without your permission. However, despite this, it is necessary to provide for a slight slope for the site. This will make it easier for the car to enter the parking lot. Also, make sure that the site is not in a low place, but slightly above ground level. Then rainwater and snow will not stagnate here.
Site device
The construction of the site begins with the removal of a layer of soil with a thickness of 10-20 cm in a selected place. A sand or crushed stone pillow is poured into this small pit and tamped.
Concrete screed
If the soil on the site is sufficiently stable and not subject to seasonal displacements, then you can stop at a concrete screed, reinforced with reinforcement. For this, a wooden formwork from an edged board of the required height is installed along the perimeter of the site. A layer of concrete about 5 cm thick is poured over the sand, on which a reinforcing mesh is immediately placed, without waiting for solidification. From above, it is again poured with concrete.
The thickness of the concrete platform should be at least 10 cm, but if the car is large and heavy, then it is better to increase this figure. Despite the fact that the concrete will set in 2-3 days (at this time it will already be possible to remove the formwork), it is not yet possible to operate it. Wait another month for the concrete to reach its final strength - then it can support the weight of the machine.
Paving slabs
In the event that the soil is prone to swelling, then after a year the concrete surface of the site can be cracked, so another option must be preferred. A good choice can be paving slabs, which, due to the gaps between themselves, will allow moisture to evaporate better from the surface of the ground and the base of the parking lot will be less warped.
Such tiles can be of completely different textures and colors - stylized for a certain type of wood or stone. For car parking, it is better to use granite-like tiles.
It is very easy to lay paving slabs - on a tamped crushed stone pillow or on a layer of sand and cement. No other binders such as glue are required. The tile is nailed to the surface with a special rubber hammer and adheres tightly to the base. After the tile is laid, it is advisable to install a curb along its borders. Instead of tiles, paving stones, natural stone, clinker bricks can be used as facing the site.
Crushed stone filling
In the case of swollen soils, ordinary crushed stone can also be used for the site surface. It is enough to fill in a layer of rubble into the dug hole and the parking lot is ready.
Lawn grill
And this is already an option for lovers of environmentally friendly coatings that fit perfectly into the natural landscape. Ecoparking is a special rigid plastic lattice that creates a base for the soil in which lawn grass is sown.
The polymer grill will evenly distribute the weight of the machine over the entire area, so wheel ruts will not form on the grass and the lawn will always look well-groomed. The advantages of eco-parking are durability (up to 25 years), drainage, frost resistance. The grille does not require any maintenance during the entire period of use, however, it is relatively expensive.
Canopy over the site
Regardless of what kind of cover you prefer for your parking, it is undesirable to leave it open to rain and sunlight. The modern construction market offers a huge selection of carports. A canopy is very popular, which is a lightweight structure made of a steel frame and a roof - coverings made of polycarbonate, slate, metal tiles, corrugated board.
Such designs are sold ready-made, or they can be ordered in parts. If you wish, you can make such a canopy yourself. This will require supporting and transverse metal pipes, from which the frame is constructed using welding or bolts. From above, the roof is covered with wooden planks, slate or roofing felt - depending on what you have available.
Thus, a parking lot for a car in a country house can have a wide variety of views - from frankly urban (with a platform made of concrete and a canopy made of polycarbonate) to the most natural (eco-parking with a wooden canopy). The main thing is that it could protect the car from external negative factors and fit into the overall style of your site.
Technical requirements
EN 13108-6: 2006
(NEQ)
|
Moscow Standardinform 2012 |
Foreword
The goals and principles of standardization in the Russian Federation are established by the Federal Law of December 27, 2002 No. 184-FZ "On technical regulation", and the rules for the application of national standards of the Russian Federation - GOST R 1.0-2004 "Standardization in the Russian Federation. Basic provisions "
Information about the standard
1 DEVELOPED by the Autonomous Non-Profit Organization Scientific Research Institute of the Transport and Construction Complex (ANO NII TSK) and the 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 PUT INTO EFFECT by the Order of the Federal Agency for Technical Regulation and Metrology dated September 14, 2011 No. 297-st
4 This standard has been developed taking into account the main regulatory provisions of the European regional 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)
5 INTRODUCED FOR THE FIRST TIME
Information about changes to this standard is published in the annually published information index "National Standards", and the text of changes and amendments is published in monthly published information indexes "National standards". In case of revision (replacement) or cancellation of this standard, the corresponding notice will be published in the monthly published information index "National standards". Relevant information, notice 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
GOST R 54401-2011
NATIONAL STANDARD OF THE RUSSIAN FEDERATION
Public roads
ASPHALT CONCRETE ROAD CAST HOT
Technical requirements
Automobile roads of general use. Hot road mastic asphalt. Technical requirements
Date of introduction - 2012-05-01
1 area of use
This standard applies to hot cast asphalt road concrete and hot cast asphalt road concrete mixtures (hereinafter referred to as cast mixes) used for paving on public roads, bridge structures, tunnels, as well as for patching, and establishes technical requirements for them. ...
2 Normative references
This standard uses normative references to the following standards:
Appointment
Type of
Maximum size
grains of mineral
parts, mm
30-51
40 to 50
New construction, major and patching repairs
15-30
30 to 45
New construction, major and patching repairs, sidewalks
0-15
20 to 35
Sidewalks, bike paths
5 Technical requirements
5.1 Cast mixtures must be prepared in accordance with the requirements of this standard for technological regulations approved in the prescribed manner by the manufacturer.
5.2 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 specified in the table
Table 2
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Grain size, mm, finer * |
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1,25 |
0,63 |
0,315 |
0,16 |
0,071 |
||||||
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95-100 |
80-100 |
67-87 |
49-70 |
42-59 |
36-52 |
30-48 |
26-2 |
22-34 |
19-30 |
|
|
98-100 |
87-100 |
70-85 |
54-71 |
44-62 |
36-54 |
31-45 |
26-37 |
20-32 |
||
|
98-100 |
85-100 |
62-88 |
48-79 |
39-70 |
31-59 |
26-8 |
20-40 |
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* Total passes of mineral material, in percent by weight. |
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Grain compositions of the mineral part of mixtures of cast and asphalt concrete based on them, when using square sieves, are given in the appendix.
The graphs of the permitted granulometric compositions of the mineral part of the cast mixture are given in the appendix.
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
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Standards for types of mixtures |
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1 Porosity of the mineral backbone,% by volume, no more |
Not standardized |
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2 Residual porosity,% by volume, no more |
Not standardized |
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3 Water saturation,% by volume, no more |
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4 Temperature of the mixture during production, transportation, storage and laying, ° С, not higher |
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5 Tensile strength at fracture at a temperature of 0 ° C, MPa (optional): |
Not standardized |
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not less |
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no more |
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* The values correspond to the maximum temperature of the mixture based on the conditions for using polymer-bitumen binders. ** The values correspond to the maximum temperature of the mixture from the conditions of use of viscous oil road bitumen. |
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5.5 The maximum temperature indicated in the table is valid for any place in the mixing mechanism and containers for storage and transportation.
5.6 The values of the index of the indentation depth of the stamp, depending on the purpose and place of application of mixtures of cast and asphalt concrete based on them, are indicated in the table.
Table 4
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Type of work |
The range of the index of indentation of the stamp for the types of mixtures, mm |
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1 Motor roads of general use with traffic intensity ≥ 3000 vehicles / day; bridge structures, tunnels. |
Device top layer coverings |
1.0 to 3.5 Increase after 30 min No more than 0.4 mm |
Not applicable |
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|
Device bottom coating layer |
1.0 to 4.5 Increase after 30 min No more than 0.6 mm |
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2 Motor roads of general use with intensity< 3000 авт/сут |
Topcoat device |
1.0 to 4.0 Increase after 30 min No more than 0.5 mm |
Not applicable |
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Bottom coating device |
1.0 to 5.0 Increase after 30 min No more than 0.6 mm |
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3 Pedestrian and bicycle paths, crossings and sidewalks |
The device of the upper and lower layers of the coating |
Not applicable |
from 2.0 to 8.0 * |
from 2.0 to 8.0 * |
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4 All types of roads as well as bridges and tunnels |
Top patching coating layer; device leveling layer |
1.0 to 6.0 Increase after 30 min No more than 0.8 mm |
Not applicable |
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* The increase in the index of indentation of the stamp during the next 30 minutes is not standardized. |
|||||
The index of the indentation depth of the stamp at a temperature of 40 ° C during the first 30 min of the test and (if necessary) the increase in the index of the indentation of the stamp during the next 30 min of the test is determined in accordance with GOST R.
5.7 Poured mixtures must be homogeneous. The uniformity of cast mixtures is assessed in accordance with GOST R 54400 by the coefficient of variation of the values of the indentation depth of the stamp 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 a cast mixture of type III is not standardized. The homogeneity indicator of the cast mixture is determined at intervals of at least monthly. It is recommended to determine the homogeneity indicator of the cast mixture for each manufactured composition.
5.8 Material requirements
5.8.1 For the preparation of cast mixtures, crushed stone obtained by crushing dense rocks is used. Crushed stone from dense rocks, which is part of cast mixtures, must comply with the requirements of GOST 8267.
For the preparation of 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 clogging impurities in the crushed stone.
Physical and mechanical indicators of crushed stone must meet the requirements specified in the table.
Table 5
|
Indicator values |
Test Method |
|
|
1 Grade by crushing, not less |
1000 |
|
|
2 Abrasion grade, not less |
||
|
3 Brand for frost resistance, 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,A eff, Bq / kg: |
||
|
Up to 740 |
||
|
Up to 1350 |
5.8.2 For the preparation of cast mixtures, sand from crushing screenings, natural sand, and also their mixture are used. The sand must meet the requirements of GOST 8736. In the production of cast mixtures for the upper layers of road surfaces and bridge structures, sand from crushing screenings or its mixture with natural sand, containing no more than 50% of natural sand, should be used. The grain size composition of natural sand should correspond to the size of the sand not lower than the fine group.
The physical and mechanical properties of the sand must meet the requirements specified in the table.
Table 6
|
Indicator values |
Test Method |
|
|
1 Grade of sand strength from crushing screenings (original rock), not lower |
1000 |
|
|
4 Specific effective activity of natural radionuclides, A eff, Bq / kg: |
||
|
For road construction within settlements; |
Up to 740 |
|
|
For road construction outside settlements |
Up to 1350 |
5.8.3 For the preparation of cast mixtures, a non-activated and activated mineral powder that meets the requirements of GOST R 52129 is used.
The permissible content of powder from sedimentary (carbonate) rocks from the total mass of the mineral powder must be at least 60%.
It is allowed to use technical dust from the entrainment 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 dust from the entrainment of acidic rocks is allowed provided that it is contained in the total mass of the mineral powder in an amount of not more than 20%. The values of the indicators of dust entrainment must comply with the requirements of GOST R 52129 for powder grade MP-2.
5.8.4 For the preparation of cast mixtures, viscous oil road bitumens of grades BND 40/60, BND 60/90 in accordance with GOST 22245 are used as a binder, as well as modified and other bituminous binders with improved properties in accordance with regulatory and technical documentation agreed 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 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 bitumen should be used. In these cases, preference should be given to polymer-bitumen binders based on block copolymers of the styrene-butadiene-styrene type, brands PBV 40 and PBV 60 in accordance with GOST R 52056.
5.8.6 When designing compositions of cast mixtures, the type of binder should be assigned taking into account the climatic characteristics of the construction area, the purpose and place of application of the structural layer, the required (projected) deformative properties of mixtures of cast and asphalt concrete based on them. The suitability of the binder to achieve the required functional characteristics of mixtures of cast and asphalt concrete based on them is confirmed in the process of 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 dephlegmators into their composition, which make it possible to reduce the temperatures of production, storage and laying of cast mixtures by an amount from 10 ° C to 30 ° C without impairing their workability. The introduction of reflux condensers is carried out into bitumen (polymer-bitumen binder) or into a cast mixture during its production on an asphalt mixing plant.
5.8.8 The specified composition of the cast mix must be ensured during its production on an asphalt mixing plant. It is forbidden to change the composition of the cast mixture after the completion of the production process by introducing binder, oil products, plasticizers, resins, mineral materials and other substances into the mobile coher 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 allowed to use recycled asphalt concrete (asphalt granulate) as an aggregate in a cast mix. Moreover, its content should not exceed 10% of the mass fraction of the composition of the mixture cast for the device of the lower or upper layers of the road surface and patchwork and 20% of the mass fraction of the composition of the mixture cast for the device of the leveling layer. At the request of the consumer, the permissible percentage of asphalt granulate in the cast mix can be reduced. The maximum size of crushed stone grains contained in asphalt granulate should not exceed the maximum size of crushed stone grains in the cast mix. When designing compositions of mixtures cast using asphalt granulate, one should take into account the mass fraction of the content and properties of the binder in the composition of this aggregate.
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 in accordance with GOST 12.1.007, referring to low-hazard substances by the nature of the hazard and the degree of impact on the human body.
6.3 The norms of maximum permissible emissions of pollutants into the atmosphere during the production 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 mixes must meet the requirements of GOST 12.1.005.
6.5 Specific effective activity of natural radionuclides in mixtures of cast 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 the enterprise on one mixing plant during one shift, using raw materials from the same 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, the water saturation, the depth of indentation of the stamp and the composition of the cast mixture are determined. The parameters of the porosity of the mineral skeleton and the residual porosity and the indicator of the specific effective activity of natural radionuclides are determined when selecting the compositions of the cast mixture, as well as when changing the composition and properties of the starting materials.
7.5 During operational control of the quality of cast mixtures in production, the temperature of the cast mixture in each shipped vehicle is determined, which must not be lower than 190 ° C.
7.6 For each batch of the shipped cast mix, the consumer is issued a quality document containing the following information about the product:
Manufacturer's name and address;
Number and date of issue of the document;
Name and address of the consumer;
Order number (batch) and quantity (weight) of the cast mix;
Type of cast mixture (composition number according to the manufacturer's nomenclature);
The temperature of the cast mix during shipment;
The brand of the binder used and the designation of the standard by which it was produced;
Designation of this standard;
Information about the added 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 the data of acceptance tests and tests performed during the selection of the composition, according to the following indicators:
Water saturation;
The depth of indentation of the stamp (including an increase in the indicator after 30 minutes);
Porosity of the mineral part;
Residual porosity;
Uniformity of the cast mix (according to 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 carry out a control check of the conformity of the supplied mixture cast to the requirements of this standard, observing the sampling, sample preparation and testing methods specified in GOST R 54400.
8 Test methods
8.1 The porosity of the mineral framework, residual porosity, water saturation, depth of indentation of the stamp, composition of the cast mixture, tensile strength during splitting of cast asphalt concrete are determined in accordance with GOST R 54400.
In the case of using square sieves in the selection of grain compositions for determining the grain composition of the cast mixture, it is necessary to use a set of sieves in accordance with the appendix.
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 with 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.
In the absence of data on the content of natural radionuclides, the manufacturer of the cast mixture carries out incoming control of materials in accordance with GOST 30108.
9 Transport and storage
9.1 The prepared cast mixtures should be transported to the place of placement in cochiers. It is not allowed to transport the mixture cast in dump trucks or other vehicles in the absence of installed and functioning systems for mixing and maintaining the temperature.
9.2 The maximum temperature of the cast mixture during storage must correspond to the values indicated in the table or to the requirements of technological regulations for this type of work.
9.3 Mandatory conditions for the transportation of cast mixtures to the place of laying:
Forced stirring;
Elimination of segregation (stratification) of the cast mix;
Protection from cooling, atmospheric precipitation.
9.4 In case of long-term transportation or storage of the mixture cast in stationary coppers on asphalt mixing plants, its temperature should be reduced for the period of the expected storage time. When storing a cast mixture from 5 to 12 hours, their temperature should be lowered to 200 ° C (when using polymer-bitumen binders) or to 215 ° C (when using viscous oil bitumen). After the end of the storage period, immediately before the production of laying work, the temperature of the cast mixture is increased to the permissible values indicated in the table or in the technological regulations for this type of work.
9.5 The time elapsed from the production of the mixture cast on the asphalt mixing plant to its complete unloading from the mobile coher when laying in the pavement should not exceed 12 hours.
9.6 The cast mix must be disposed of as construction waste if the following conditions are met:
Exceeding the maximum permissible shelf life of the cast mix;
Unsatisfactory workability of the mixture, loss of the ability to be a casting mixture and the ability to spread over the base, friability (incoherence), the presence of brown smoke emanating from the cast mixture.
9.7 Instrumentation monitoring the temperature of the poured mixture on an asphalt mixing plant and in a coher (stationary and mobile) must be calibrated (verified) at intervals of at least once every three months.
10 Directions for use
10.1 The device of coatings from a cast mixture is carried out in accordance with the technological regulations, approved in accordance with the established procedure.
10.2 The cast mixture must be placed in the coating only in a liquid or viscous-flowing state, which does not require compaction.
10.3 Laying of cast mixes should be carried out at the temperature of the ambient air and the underlying structural layer not lower than 5 ° С. It is allowed to use cast mixtures at an ambient temperature of up to minus 10 ° C to carry out work to remove an emergency on the carriageway of highways with asphalt concrete pavements. In these cases, measures should be taken to ensure a sufficient quality of adhesion between cast asphalt concrete and the underlying structural layer.
10.4 Cast mixtures for paving, sidewalk and patchwork should 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 surface prepared by cold milling, such surfaces should be pretreated with a bitumen emulsion in accordance with GOST R 52128 with a consumption of 0.2 - 0.4 l / m 2 in order to ensure proper adhesion of the layers. The accumulation of emulsion in lowered areas of the base surface is not allowed. Mandatory is the requirement for the complete disintegration of the emulsion and evaporation of the resulting moisture before the start of the casting of the cast mixture. The use of bitumen for surface treatment instead of bitumen emulsion is not allowed.
The emulsion treatment of the underlying poured asphalt concrete layer is not performed when the lower and upper pavement layers are made of poured asphalt concrete.
The emulsion treatment of the underlying layer of cast asphalt concrete is not allowed to be carried out when the upper layer is made of crushed stone-mastic asphalt concrete mixture according to GOST 31015 with a time interval between the device of layers not exceeding 10 days, as well as in the absence of traffic during this period along the underlying layer.
10.5 The value of the maximum permissible longitudinal and transverse slopes of the road structure, when using a cast mixture, is from 4% to 6%, depending on the characteristics of the given composition of the cast mixture and its viscosity.
10.6 Cast mixes of all types are allowed to be laid both mechanically using a special device for leveling the cast mix (finisher), and by hand. The required workability of cast mixtures is achieved by the manufacturer by adjusting the specified composition and selecting a bituminous binder, introducing reflux condensers during the production of the cast mixture, provided that the strength characteristics specified in Art. Workability can be controlled by changing the temperature of the cast mix during its laying, taking into account the requirements for the minimum and maximum permissible temperatures of the cast mix. Mixture intended for mechanized paving may have higher viscosity and lower spreading speed over the surface during unloading.
10.7 The final stage of paving with a top layer of cast asphalt concrete is the arrangement of a rough surface, carried out by the "hot" injection method in accordance with the technological regulations approved in accordance with the established procedure.
10.8 Physical and mechanical indicators of crushed stone used for the device of the rough surface of the top layer of the asphalt concrete pavement cast by the hot injection method must comply with the requirements given in the appendix.
For the device of the rough surface of the upper layers of the asphalt concrete road cast hot by the hot injection method, fractionated crushed stone of igneous rocks of fractions from 5 to 10 mm, over 10 to 15 mm and a mixture of fractions from 5 to 20 mm according to GOST 8267 with a consumption of 10 - 15 kg / m 2.
When arranging the lower layers of coatings from cast mixtures, in order to additionally ensure adhesion with the upper layers of coatings from all types of compacted asphalt concrete, crushed stone of igneous rocks of fractions from 5 to 10 mm is distributed "hot" with a consumption of 2 - 4 kg / m 2. It is allowed not to sprinkle the bottom layer with crushed stone when installing two-layer pavements from cast asphalt concrete, provided there is no movement along the bottom layer of the pavement.
To ensure proper adhesion of surface crushed stone to cast asphalt concrete, it is recommended to use bitumen treated crushed stone (blackened crushed stone). The bitumen content should be selected so as to exclude its runoff, crushed stone adhesion or uneven bitumen coverage of the crushed stone surface.
Physicomechanical indicators of crushed stone used for the device of a rough surface of the upper layers of asphalt concrete poured by the injection method must comply with the requirements presented in the table.
Table A.1
|
Indicator values |
Test Method |
|
|
Rock crushing grade, not lower |
1200 |
|
|
Rock abrasion grade, not lower |
||
|
Frost resistance grade, not lower |
F100 |
|
|
Weighted average content of lamellar (flaky) and needle-shaped grains in a mixture of crushed stone fractions,% by weight, no more |
||
|
The total specific effective activity of natural radionuclides, A eff, Bq / kg: |
||
|
For road construction within settlements; |
No more than 740 |
|
|
For road construction outside settlements |
No more than 1350 |
The recommended temperature range of the mixture cast at the beginning of the process of distributing grain mineral materials over its surface is from 140 ° C to 180 ° C and must be specified during the production process.
For the device of a rough surface of footpaths, sidewalks and bicycle paths, natural fractionated sand is used with a consumption of 2 - 3 kg / m 2.
Table A.2
|
Test sieve size, mm |
|||||||||||
|
0,63 |
0,315 |
0,16(0,14) |
0,05 |
||||||||
|
Total residues,% by weight |
0-30 |
30-60 |
60-90 |
0,25 |
0,125 |
0,063 (0,075) |
|||||
|
95-100 |
78-100 |
62-83 |
54-72 |
49-62 |
42-59 |
37-54 |
29-48 |
25-40 |
21-34 |
19-30 |
|
|
95-100 |
83-100 |
72-89 |
Figure B.3 - Grain composition of type II mix (round sieves)
Figure B.4 - Grain composition of type II mix (square sieves)
Figure B.5 - Grain composition of type III mix (round sieves) Figure B.6 - Grain composition of type III mixture (square sieves) BibliographySNiP 3.06.03-85 Highways Key words: hot cast asphalt road concrete mixes, hot cast road asphalt concrete, road coverings | ||||||||
It is always convenient to drive in a car on a flat and smooth highway, developing a high speed. It is not uncommon that the quality of the track does not allow this, since the coverage has a deviation from the norm and is of little use for high-quality driving. Over time, under the pressure of the wheels of machines, especially large trucks, the influence of unfavorable natural conditions in the form of rain, hail, a sharp change in temperature, asphalt concrete flooring loses its original appearance. It is covered with small cracks, pits, potholes, which shortens the time of high-quality work of the highway. Driving on such worn-out roads leads to damage to vehicles and can even lead to an accident.
Causes of destruction
As a result of using asphalt concrete pavements, they undergo various deformations. Depreciation of roads is formed due to external and internal influences on. Defects on the coating from the influence of external factors include:
- power loads from automobile wheels;
- precipitation (rain, temperature changes, thawing, snow, freezing).
The main causes of destruction are non-compliance with the technology of paving or repairing the roadway and the impact of cars. Internal factors associated with the destruction of the asphalt concrete pavement arise due to improper design for roads, their construction and repair:
- Incorrect design of an asphalt-concrete highway leads to the destruction of the road surface. Inaccurate studies, calculations and mistakes made in determining the intensity of the flow of vehicles 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 violated; the base soil will sag; the strength of the soil cushion will decrease; wear of the asphalt concrete flooring will follow.
- Old techniques were applied and low quality materials were selected when working with asphalt concrete pavement. More recently, for the installation, laying of asphalt mortar and repair of the tracks, hot ones were used, which included low-quality bitumen. It caused damage to the road surface and deteriorated the strength characteristics of the ready mix for asphalting the road surface. However, the construction does not stand still, and today the newest polymer-bitumen materials are being developed and introduced, which can significantly increase the properties of the material and the future route. Various additives have become very popular in the mixture for: improving adhesion, increasing resistance to water and cracking. Thanks to these additives, the resistance of the roadway to subzero temperatures is ensured. To avoid defects and wear on the roadway, not only should new mixes be used for asphalt paving, but also new technologies should be chosen that will stabilize and strengthen weakened moving soils of the base. To prevent deterioration of the pavement, a reinforcing mesh is used, which will strengthen the road structure and increase the service life of the asphalt road.
- Defects and wear on the asphalt concrete pavement occur due to an incorrect technological process during the construction of a road structure. Destruction is formed due to mistakes made when laying asphalt and repairing the track. Contribute to the occurrence of defects in violation of the rules for the transportation of asphalt concrete mortar, as a result of which the mixture is supplied at the wrong temperature. When compaction of the laid mixture, air bubbles were not removed or, on the contrary, the solution was too compacted, then the asphalt road will begin to crack and delaminate. Destruction of the route can occur as a result of poor-quality preparation of the ground bed and works on laying the road structure.
- Defects on the road surface are most often formed as a result of weather conditions, when, during rains, moisture penetrates the asphalt road, and the hot rays of the sun spoil the upper layer of the track - the strength of the asphalt concrete deteriorates, which leads to the formation of potholes. In the period of subzero temperatures, the collected 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 roadbed is destroyed. High loads on the track surface are caused by an intensive traffic flow, as a result of which the throughput rate is exceeded in 24 hours and, as a consequence, the track bed resource is reduced. An increase in the axial load due to the operation of the road surface by vehicles with a large carrying capacity leads to the destruction of the asphalt concrete road, the formation of ruts and cracks.
Damage to the road surface made of asphalt concrete can occur due to the complex influence of external and internal factors.
Main types of defects
Typical road defects. Asphalt concrete damages are of the following types:
- Break. It is a slot in the asphalt area where the flow of vehicles passes. If cracks are not patched in time, they can grow in size and turn into a large-diameter breach.
- Expiration of service life. The destruction associated with the long-term operation of the road, on which no repairs have been carried out, affect the thickness of the asphalt concrete layer.
- Reducing the strength of asphalt concrete. As a result of heavy loads from heavy-duty trucks, the web is sagging and the top layer of the coating is destroyed in the form of irregularities, potholes and ruts.
- Potholes. Pothole fractures are depressions with a sharp edge cut, which occur due to improper masonry of asphalt concrete using poor quality materials.
- Peeling. The formation of peeling on the road surface due to the separation of the coating particles from the upper layer. Formed due to constant variable impacts on the road surface of frost and thaw.
- Climatic influences. During the melting of snow masses, a large amount of liquid is formed, which is capable of destroying the track bed, which entails a decrease in the strength characteristics of asphalt concrete.
- Chipping. This type of damage occurs due to a violation of the laying or repair of the roadway, namely, work in atmospheric precipitation or sub-zero temperatures.
- Cracks. Cracks are formed on the road surface as a result of a sharp change in temperature.
- Drawdown. Subsidence occurs due to the selected poor quality materials for laying the road, as well as as a result of insufficient compaction of the asphalt mixture or soil.