Asphalt pavement: advantages and disadvantages. Service life of asphalt pavement. A warranty period will be established for road works Warranty periods for the operation of asphalt concrete pavement

15.05.2020

Asphalt laying is a rather complicated and time-consuming process, but at the same time effective way pavement devices. The range of work performed includes: excavation, foundation, asphalt laying, landscaping.

The work performed at a professional level will allow you to create not only a reliable and stable road surface, but also ensure its long-term service life. Specialists START CITY GROUP help you choose best option 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, liquid bituminous substance. All substances are selected in the optimal amount and mixed in a heated state.

Crushed stone, which is part of 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 complies with established Russian standards.

The scope of application of asphalt concrete is wide: the construction of a roadway, squares, sidewalks, parking areas, a park area 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 the use of the selected material.

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

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

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

Stacking technology. Stages. materials

To date, two technologies for the construction of the roadway are used:

hot asphalting;
cold asphalt.

Each of them has its pros and cons:

Hot asphalt. The mixture is prepared from viscous and liquid petroleum bitumen. Laying can be carried out in winter. The temperature of the mixture should not be less than 120 degrees. Before asphalt is laid, a piece of the road, on which the asphalt concrete mixture will be applied, is dried with special equipment.
Cold paving. The mixture is prepared from liquid petroleum road bitumen. Laying works are carried out only in the warm season, since this technology does not dry the water. Cold asphalting is often used for patching.

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

Asphalt laying consists of several stages:

1. Development of design estimates

Each site is individual: it has its own size, topography and configuration, soil characteristics, remoteness and features of access roads. Based on these criteria, after the departure of a specialist, it is determined total area, volume and preliminary cost of works.

2. Territory development, excavation

Preparation of the territory for the installation of an asphalt canvas begins with the removal of the top layer of soil. As a rule, bulldozers and loaders are involved to remove a large soil layer. Graders are used to level the surface of the base. According to the given marks, the formation of a road "trough" is carried out with its further compaction.

If there is an old coating on the asphalted area, then it is destroyed by a road mill. With proper recycling, the old coating can be reused.

3. Foundation preparation

It is the turn of the formation of a "road pillow". To do this, two layers of the 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 fine fraction is poured to minimize voids. Each layer of the base is leveled by a grader and carefully compacted. A side stone is installed along the edges of the site. In order for asphalting to be of high quality, before laying asphalt, the surface of the site is shed with bitumen.

4. Asphalt paving

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

The mixture is evenly distributed over a given area. For laying the last layer of the mixture, asphalt pavers are used. Asphalt rolling is carried out by several rollers for the best consistent compaction. Our company has formed its own material basis - a modern fleet of special equipment, which has about 40 units of equipment, which fully ensures the entire process of road construction.

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

Road time

It should be noted that asphalt paving is a seasonal work 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 should occur as quickly as possible so that it does not have time to cool. Otherwise, it will be impossible to lay asphalt.

Service life

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

The guaranteed service life is approximately 7 - 10 years. But you need to take into account the fact that with intensive use, the specified period can be reduced. Timely repair work of the roadway, which includes the elimination of pits, subsidence, cracks and irregularities, will help to extend the operational life.

DEPARTMENTAL BUILDING REGULATIONS

REGIONAL AND INDUSTRY REGULATIONS
SERVICE LIFE
FLEXIBLE TRAVELING
AND COATINGS
(VSN 41-88)

Agreed by Gosstroy of the RSFSR

Approved

Minavtodor of the RSFSR

Moscow 1999

Regional and sectoral norms of overhaul periods of service of non-rigid pavements and coatings (VSN 41-88) / Ministry highways RSFSR. - M.: GUP TsPP. 1999. Standards of overhaul service life of non-rigid pavements are developed in accordance with direction 02 of the Program for solving the scientific and technical problem 0.55. II-P "... To develop, improve and introduce progressive technical solutions and technologies for the repair and maintenance of highways and artificial structures for 1986-1900." The document is intended for specialists of road organizations involved in the design and operation of roads. Giprodornii of the RSFSR Minavtodor, the Leningrad branch of Soyuzdornia, MADI, Rostov, Sverdlovsk, Saratov and Khabarovsk branches of Giprodornia, SibADI, the Computing Center of the RSFSR Minavtodor, Azdorproekt and the Scientific Research Laboratory of the Minstroyavtodor of the AzSSR, NPO "Dorstroytechnika" of the Mindorstroy of the BSSR, Gruzgosorgdornia, the Kazakh branch of Soyuzdornia, KirgizavtodorKTI, Vilnius ISI and Orgtehdorstroy trust of the Ministry of Automotive Road of the Lithuanian SSR, Orgdorstroy trust of the Minavtodor of the Moldavian SSR, Central Asian branch of Soyuzdornia, KADI, Gosdornia and HADI. The list of participants is given in Appendix 2. When preparing the document, comments and suggestions from the road ministries of the Union republics were taken into account. 1. These standards are intended to develop standards for long-term planning of funding volumes for the repair of public roads, clarify the norms for the consumption of materials and cash costs for road repairs, as well as for use in calculating the strength of the designed pavement and reinforcement layers of structures in operation. 2. The service life of pavement is the period of time within which the bearing capacity of the road structure is reduced to a level that is maximum permissible under traffic conditions. Repair of pavement is carried out when the calculated level of pavement reliability and the corresponding limit state of the pavement in terms of evenness are reached during operation. Under the reliability of pavement is understood (in accordance with the Instruction for the design of non-rigid type pavement VSN 46-88 of the USSR Ministry of Transport and Construction) the probability of failure-free operation of the structure during the entire period of operation until repair. Quantitatively, the level of reliability represents the ratio of the length of strong (undamaged) sections to the total length of the pavement with the corresponding value of the strength factor. 3. Regulatory overhaul periods of pavement service and the corresponding standards of reliability levels are taken according to Table. one .

Table 1

Norms of overhaul (estimated) service life (T 0) and norms of reliability levels (K n) of non-rigid pavements

Intensity of traffic flow, vehicles/day	Pavement type	Road-climatic zone

			T 0 , years	T 0 , years	T 0 , years
	capital
	capital
	capital
	lightweight
	capital
	lightweight
	transition
	lightweight
	transition

Notes. 1. Intermediate values are taken by interpolation (for K n and T 0). 2. When calculating the layers of strengthening of capital and lightweight pavements, it is allowed to reduce the service life norm by 15% from the minimum values while maintaining the reliability level norm. 3. When designing roads for the calculation of pavements, it is recommended to use the norms of the longest service life from the specified range for each type of pavement. 3.1. For existing roads: Category III with transitional clothes, the overhaul periods and reliability levels are taken the same as for roads of category IV; Category V with capital type clothes, the norm of the overhaul period of service should be increased by 20%, and the norm of the level of reliability should be reduced by 30% compared with the norms established for roads of category III with a similar surface; Category IV with lightweight clothing at a traffic intensity of 100-500 vehicles / day. normalized indicators are taken the same as for roads of category V. If the actual intensity of the traffic flow on the road exceeds the calculated one established for the considered category of roads, the norm of the overhaul life of the pavement is reduced by 20% while maintaining the norm of the level of reliability. When the traffic intensity is less than the standard, the reliability level is reduced to 15% while maintaining the service life rate. 3.2. When planning and carrying out repairs using the thermal profiling method, the level of pavement reliability is reduced by 10%. 3.3. In the regional conditions of the RSFSR, it is allowed to lower the norm of the level of reliability of pavements against the values \u200b\u200bgiven in Table. 1. on: 2% - in the Urals (Perm, Sverdlovsk regions), East Siberian (Amur, Irkutsk, Chita regions, Buryat ASSR, Yakut ASSR) and West Siberian regions (Tomsk and Tyumen regions, Krasnoyarsk Territory, north Omsk region); 5% - in the Far East region (Primorsky, Khabarovsk Territories, Sakhalin, Kamchatka, Magadan Regions). 3.4. When solving practical problems related to the assessment of the actual service life of non-rigid pavements and the transport and operational qualities of roads, they are guided by the maximum permissible operating conditions of the pavement for evenness "δ i" depending on the level of pavement reliability.

K n
δ i , cm/km

The given data was obtained using the TXK-2 pusher installed on the UAZ-452 car. When using other car brands, a preliminary calibration of the device is required. 4. The service life of the pavement is the period of time within which the adhesion properties of pavements (capital and lightweight pavements) decrease or the wear of the pavement surface (transitional and lower pavements) increases to the maximum allowable values for traffic conditions. 5. The norms of the overhaul life of pavements (T p) on roads with capital and lightweight pavements are taken depending on the intensity of the traffic flow in the first year after construction or work on the arrangement of rough surfaces during road repairs (Table 2).

table 2

Traffic intensity on the busiest lane, avt./day	Road-climatic zones	Norms of overhaul service life of road surfaces (T p)

from 200 to 2500
from 200 to 2000
from 200 to 1500
from 2500 to 4500
from 2000 to 4000
from 1500 to 3000
from 4500 to 6500
from 4000 to 6000
from 3000 to 5000
over 6500

5.1. The service life rate of the coating may be reduced by: 20% - when used as a binder for surface treatments of tar and resins; 30% - when using crushed limestone. 5.2. In cases where the overhaul life of the pavement and pavement differ by more than 30%, the overhaul life of the pavement is taken equal to 50% of the normal life of the pavement. 6. Compensation for wear of transitional pavement coatings is provided with a frequency no later than after 3 years. 7. Road-climatic zones (DKZ) are established according to the map of road-climatic zoning of the USSR (see VSN 46-83).

Appendix 1

(not approved)

Features of the application of norms in the Union republics

1. Road-climatic zones within the republics

1. Azerbaijan SSR V 2. Armenian SSR V 3. Byelorussian SSR II, III 4. Georgian SSR V 5. Kazakh SSR IV, V 6. Kirghiz SSR III, IV, V 7. Latvian SSR II 8. Lithuanian SSR II 9. Moldavian SSR III, IV 10. Tajik SSR V 11. Turkmen SSR V 12. Uzbek SSR V 13. Ukrainian SSR II, III, IV 14. Estonian SSR II consider vertical zoning. When the road is located above sea level at an altitude of 1000 to 1500 m, the service life of the pavement and the reliability level should be reduced by 7% and 3%, respectively, from 1500 to 2000 m - by 10% and 4.5%, from 2000 to 2500 by 14% and 6% and over 2500 m - by 20% and 10% respectively. It is allowed to reduce the overhaul periods of up to 30% in conditions where deformations are observed associated with the loss of stability of the subgrade. 3. In the regional conditions of the Byelorussian SSR, the service life of surface treatments (road surfaces) on motor roads of categories IV-V should not exceed 3-4 years. 4. In the regional conditions of the Uzbek SSR, it is allowed to increase the service life of road surfaces up to 7-9 years for pavements of a capital type. 5. In the regional conditions of the Ukrainian SSR and the Moldavian SSR, the minimum service life of pavement surfaces for capital and lightweight types of clothing is assumed to be at least three years. 6. In the regional conditions of the Estonian SSR, in contrast to the norms recommended in Table. 2, the longest service life of pavements of lightweight and capital types is five years. With traffic intensity per lane from 1500 to 2500 and 2500 to 6500 vehicles / day. terms of service are four and three years, respectively.

Appendix 2 List of participants in the development of standards

Apestin V.K. with the participation of Bolshakova I.V., Dudakov A.I., Ermakov M.Zh., Kulikov S.S., Stepanova T.N., Strizhevsky A.M., Tulupova E.V. (Giprodornii of the Minavtodor of the RSFSR - responsible for the implementation of research) Korsunsky M.B. (Leningrad branch of Soyuzdornia); Vasiliev A.P. with the participation of Tulaeva I.A. (MADI); Uglov V.A., Friedrich N.G., Rasnyansky Yu.I., Ivanov S.P. (Rostov-on-Don branch of Giprodornia); Roizin V.Ya., Naboka N.I., Yudina V.M. (Saratov branch of Giprodornia); Permin G.I. with the participation of Nechaeva Z.I. (Sverdlovsk branch of Giprodornia); Malyshev Alexey A., Malyshev Alexander A., Khristolyubov I.N. (SibADI); Zakurdaev I.E., Voronin A.A., Kudimova L.I. (Khabarovsk branch of Giprodornia); Burenkov Yu.N. Ponomareva N.I. (Computer Center of the Minavtodor of the RSFSR); Musaev M.M. (Azdorproekt): Akhmedov K.M., Karaisaev N.M., Abramov Y.Kh. (NIL of the Ministry of Construction and Road of the AzSSR); Karapetyan A.A. ( Technical management Minavtodor of the Armenian SSR); Pasternatsky V.A. (NPO Dorstroytechnika); Shilakadze T.A., Gegelia D.I., Daneladze R.M., Surenyan E.A. with the participation of Babaradze M.A., Bernashvili G.K., Datunashvili T.S., Evtyukhina V.E., Kiknadze Ts.V., Korashvili M.U., Levit A.A., Nozadze A.I., Chigogidze G.E., Tsereteli Z.M., Tsiklauri L.M., Natsalishvili N.N. (Gruzgosorgdornia); Kotvitsky A.F., Krasikov O.A. (Kazakh branch of Soyuzdornia); Smatov T.Sh., Tyulegenov K.A., Turgunbaev A.T., Abekov T.U. (KyrgyzavtodKTI); Palshaitis E.L. (Vilnius ISI); Dranaitis E.A., Kazhdailis P. (Trust Orgtekhdorstroy of the Ministry of Transport and Transportation of the Lithuanian SSR); Kozhushko I.G (Trust Orgdorstroy of the Minavtodor of the Moldavian SSR); Butlitsky Yu.V., Pasynsky L.N. (Central Asian branch of Soyuzdornia); Sindenko V.M., Alemich I.D., Ivanitsa E.V., Titarenko A.M. with the participation of Bulakh A.I. (CADI); Kolinchanko N.N., Kazny A.S., Nosova N.V. (Gosdornia); Mikhovich S.I., Kudryavtsev N.M., Storazhenko M.S., Kolommets V.A. (HADI).

Asphalt concrete pavement: general information

The first asphalt pavements were built in Babylon 600 BC. The construction of pavements using bitumen resumed only in the 19th century. Western Europe and then to the USA. The first section of asphalt concrete pavement in Russia was built on the Volokolamsk Highway in 1928.

Asphalt concrete pavement has a number of positive properties and high transport and operational performance: slow wear under the action of heavy vehicles; relatively high strength and resistance to climatic factors and water; hygiene (does not produce dust and is easily cleaned from 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 transverse slope is prescribed in the range of 15-20 ppm.

Pavement structures with asphalt concrete pavements are constantly changing due to the fact that traffic loads and traffic are constantly increasing. Even 20-30 years ago, two-layer asphalt concrete pavements 10-12 cm thick on a crushed stone base 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 (rolled) concrete 20-35 cm thick is increasingly used, and the total thickness of the asphalt being laid is 18-25 cm.

The service life of asphalt concrete pavements depends not only on the quality of asphalt concrete, but also on the design of the pavement. The same quality asphalt pavement performs differently on different bases. So, in asphalt concrete pavements laid on monolithic cement concrete bases, cracks appear due to the thermophysical incompatibility of the pavement and base materials, i.e., seams and cracks in cement concrete bases are repeated in asphalt concrete pavements.

Crushed stone foundations do not have this drawback, however, they are subject to uneven shrinkage due to the mutual movement of crushed stone grains under the influence of repeated transport loads.

In relation to the chosen pavement design, it is necessary to choose the type of asphalt concrete mixture. Asphalt concrete pavements should be installed in dry weather. Asphalt laying (asphalting) should be carried out at an ambient temperature of at least +5oC. Asphalt laying (asphalting) can be carried out as mechanized way, with the help of an asphalt paver, and manually.

Backfilling and restoration of roads to holiday villages and garage cooperatives, roads with slow traffic, asphalt road crumb is a progressive method of road restoration. Due to the low cost and higher resistance to destruction than crushed stone, sand. Asphalt road crumb has a higher density, is saturated with bitumen, which serves as an additional link and sealing element, which allows the road to last much longer.

The best material for backfilling roads inside holiday villages and garage communities is asphalt crumb. The advantage of crushed asphalt is that it is much denser than sand and gravel. Asphalt crumb after filling is rolled away by car wheels to such an extent that it becomes like asphalt. A road paved with crushed asphalt 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 filled with sand and gravel.

Backfilling and restoration technology, unpaved roads:

Before laying asphalt crumbs, leveling is carried out, using a motor grader, knocking down road irregularities, profiling the base, achieving the necessary evenness. After an even layer of the base is reached, the road crumb is leveled along the entire road, the slopes are profiled. Achieving uniformity of a covering of identical thickness of a layer. At the final stage, compaction is carried out 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 pavement, the new road is ready for operation.

In front of the foundation device, it is necessary to install side stones and curbs. The bases for asphalt concrete pavement pavements are made of crushed stone, slag, broken bricks, as well as other waste obtained from the dismantling of buildings and structures. Crushed old asphalt concrete (crushed asphalt) is also used as a base material. The thickness of the base is usually prescribed 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 a scattering of stone or slag fines for crushing and wedging.

The thickness of the asphalt concrete pavement is usually taken to be 3-4 cm. At the entrances to neighborhoods and courtyards, the thickness of the asphalt concrete layer is raised to 5 cm or more. For pavement pavements, sandy or fine-grained asphalt concrete mixtures are used. For compaction of asphalt concrete, vibrating plates or small-class rollers are used.

Asphalting of the sports ground

font-size:12.0pt;font-family:" times new roman>The asphalt base is built for a special sports coverage on tennis courts, volleyball, basketball and other sports grounds. The device of such a foundation includes a set of works:

Earthworks (preparation of the "trough"). Excavation and removal of soil to the required height, as a rule, to the height of the crushed stone base. Planning, leveling the soil inside the trough;

Installation side stones, curbs and drainage system along the perimeter of the site;

Device sandy base 10-20 cm thick if the soil contains clay;

Construction of a crushed stone base with a thickness of 15-18 cm. From crushed stone fractions 40x70 and 20x40. Can be used instead of crushed stone fr. 40x70, black gravel, and on the top layer - small asphalt chips. It is desirable, to increase the reliability of the crushed stone base, to perform additional sifting.

Installation of embedded parts for racks;

The top layer is made of fine-grained asphalt-concrete mixture type “G”, with a total thickness of 8 cm. Asphalt is laid in two layers of 4 cm. To drain water from the surface of the court, the base must be given a slope of 0.5 - 1 ‰ on the short side;

Due to the specifics of asphalt laying technology, it is impossible to achieve perfect evenness of the base. Therefore, before laying the sports floor, it is necessary to level the base with special mixtures.

Soil laying and compaction are carried out during planning work, construction 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. Consolidation can be superficial and deep. In both cases, it is carried out by mechanisms.

There is soil compaction by rolling, tamping and vibrating. The most preferred is a combined compaction method, which consists in the simultaneous transmission of various actions to the ground (for example, vibration and rolling), or combining compaction with another work process (for example, rolling and vehicle traffic, etc.).

To ensure uniform compaction, the dumped soil is leveled with bulldozers or other machines. The greatest compaction of the soil with the least expenditure of labor is achieved at a certain optimal moisture content for this soil. Therefore, dry soils should be moistened, and waterlogged ones should be drained.

The soil is compacted in sections (captures), the dimensions of which should provide a sufficient scope of work. An increase in the scope of work can lead to the drying 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 foundations or trenches, since the work is carried out in cramped conditions. In order to avoid damage to foundations or pipelines, the soil adjacent to them to a width of 0.8 m is compacted using vibrating plates, pneumatic and electric rammers in layers 0.15 ... 0.25 m thick. compacting backfill under floors.

The penetrations of soil-compacting machines are made with a small overlap in order to avoid omissions 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 in the process of backfilling. The scheme of work is drawn up so that the loaded transport moves along the backfilled soil layer.

Unlike ordinary concrete, cement-crushed stone mixtures contain significantly less cement and can be compacted by the static action of self-propelled smooth rollers. The base of lean concrete is laid on a technological layer of compacted crushed stone, cement soil or sand and gravel mixture with a thickness of 10-15 cm. On the 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 layers up to 20 cm and immediately compacted, first with light and then with heavy rollers, until all traces of rolling disappear.

The device of asphalt concrete pavement on lean concrete can be made after its compaction or after 2-3 days. In the latter case, the base surface should be treated with a bituminous emulsion in two layers. The total consumption of the emulsion is 0.7 kg per 1 m2 of base. The construction of lean concrete bases significantly reduces labor costs, as well as the timing of the start of asphalt concrete laying. In the bases of lean concrete, temperature transverse seams are arranged. The distance between them is taken from 20 to 40 m, depending on the air temperature when laying the concrete mixture, the brand of lean concrete and the type of asphalt concrete pavement. The seams are cut with special cutters or arranged by laying spruce or pine boards in the base.

Reinforcement of asphalt as a way to increase its durability

The issue of reinforcing the pavement 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 moves on their own or municipal wheels.

The quality of asphalt pavement 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, which have good resistance to short-term loads, have low tensile strength in bending and insufficient distribution ability under repeated load application. Therefore, fatigue and reflected cracks arising during the operation of the asphalt concrete pavement, intensively developing, 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 geogrids made of fiberglass, polyester, basalt fibers and a number of others.

According to the results of numerous laboratory studies and operating experience, the following requirements are imposed on reinforcing geogrids:

the modulus of elasticity of the reinforcing material must be greater than the modulus of elasticity of asphalt concrete in order to perceive tensile forces in the same way as it happens 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 reinforcement material to adjacent sections of the asphalt pavement. In doing so, two important factors, affecting the strength of this adhesion:

the difference between the coefficients of thermal expansion of asphalt concrete and reinforcing material should be as small as possible, since secondary local stresses arise at the place of their connection, 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 explained by 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 rigid reinforcement is applied, the main part of the tensile stresses will be taken up by it. These stresses must be transmitted to the asphalt layers via cohesive forces and a very large area of reinforcement in the asphalt would be required in order for the stresses not to exceed the forces of adhesion of the reinforcement to the asphalt.

Characteristics of some materials and finished products
Name	Modulus of elasticity, N/mm2
Asphalt	1000 – 7000
Concrete	20000 – 40000
Steel	200000 – 210000
Fiberglass	69000
polyester fiber	12000 – 18000
Hatelit geogrid strands made of polyester	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 modulus of elasticity of fiberglass, steel, basalt, on the one hand, and asphalt concrete, on the other hand, causes problems with the adhesive strength between them. Reinforcement with the mentioned materials would be possible if the reinforcing material extended over the entire width of the carriageway and sufficient reinforcement was provided 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 asphalt concrete are exceeded, delamination occurs between the mesh and asphalt concrete, and under the influence of dynamic traffic loads, relative movements appear between the mesh and asphalt, which lead to the complete destruction of the glass fibers. This was found out when taking cores, when only white powder remained from the glass mesh after several years of operation.

The reinforcement material must not be affected by dynamic loads from moving vehicles, otherwise the reinforcement will not perform well in the long term. Studies have shown that fiberglass meshes do not tolerate dynamic loads. The breaking strength of the tested fiberglass meshes dropped to 20–30% of the original value after 1000 loading cycles, and none of them survived 5000 loading cycles, while Hatelit successfully withstood 6000 cycles.

Studies of fiberglass reinforcing mesh have shown disappointing results in various conditions. On two different road sections, the behavior of glass-reinforced and unreinforced asphalt concrete was studied over a period of four years.

In the first section, the fiberglass-reinforced pavement had many more cracks in the roadway than the non-reinforced pavement.

In the second section, the final inspection showed the absence of cracks in the transition zone of both the reinforced and non-reinforced pavement. 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-interrupting reinforcement.

The most serious approach to the choice of reinforcement of asphalt concrete pavements should be taken in the construction of runways for airfields with asphalt concrete pavement. 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 asphalt concrete on the runway is a direct path to a catastrophe with human casualties.

The most optimal choice for reinforcing asphalt concrete in comparison with glass mesh is a reinforcing mesh of the Hatelit type. This type of grid has rather high technical and economic indicators:

a significant reduction in the thickness of asphalt concrete;

increasing its crack resistance by 3 times or more;

increasing the life of the coating and reducing the operating costs of its maintenance.

The use of fiberglass reinforcing meshes did not positive effect due to their low physical and mechanical characteristics and inability to effectively prevent the development of cracks in asphalt concrete.

Despite the fact that new types of fiberglass reinforcing meshes are constantly being developed, their effectiveness and durability remain significantly lower than those of polyester meshes of the Hatelit type.

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, well perceive not only stresses in the horizontal plane, but also stresses from repeated vertical loads. Polyester threads are resistant to vertical stresses and deformations. Glass threads do not perceive vertical deformations and stresses;

already in the factory, the mesh is treated with bitumen, which ensures 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 during laying without additional operations;

the dimensions of the reinforcing mesh cell should be equal to twice the size of the largest fraction of crushed stone. For fine-grained asphalt concrete optimal size grid cells 40x40 mm.

It should also be noted that during dynamic bending tests of samples at maximum tensile stresses equal to 10 MPa, the number of cycles to failure for a sample with Hatelite C is 13 times higher than for a sample 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, reduce its ability to deform and fracture with an increase in the number of compaction cycles or simply passages of heavy vehicles during roadworks. For comparison, Hatelit C has a coefficient mechanical damage even with a 5-fold compaction, it remained within the permissible range - it did not exceed 1.15.

Studies on shear resistance showed that for a core with Hatelit C it is 34 kN/m (due to good bituminous impregnation, melting and compaction nonwoven fabric applied to the grid), and for the core with a basalt grid, the shear resistance was 6 kN/m with the minimum allowable value of 15 kN/m.

In addition, the consumption of 70% bitumen emulsion when laying Hatelit S mesh is 0.3–0.5 l/m. sq., and when laying a grid of basalt - 1.0–1.2 l / m. 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 Hatelit 40/17 C mesh for reinforcing asphalt concrete”.

Road reinforcement:	Geogrid Hatelit S in rolls:

Geogrid Hatelit 40/17 C:	Asphalt laying over Hatelit 40/17 C geogrid:

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 that it is time to build a stationary parking lot for your “iron horse”, protecting it from hot sunlight and precipitation during your summer vacation. The easiest and fastest in execution is parking for a car in the country in the form of a platform with a canopy. Let's talk about how to build such a parking lot and select materials for it.

Selecting a parking location

The place for "rest" of your car should be located on a flat area. The hillside is categorically not suitable for parking, since subsequently you will have to constantly put the car on the handbrake, 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 lowland, but slightly above ground level. Then you won't stagnate here rainwater and snow.

Site device

The device of the site begins with the removal of a layer of soil 10-20 cm thick in a selected place. A sand or crushed stone cushion is poured and tamped into this small pit.

Concrete screed

If the soil on the site is sufficiently stable and not subject to seasonal shifts, then you can stop at concrete screed reinforced with reinforcement. To do this, a wooden formwork made of edged board required height. 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 be possible to remove the formwork), it cannot yet be exploited. Wait another month until the concrete reaches its final strength - then it can support the weight of the machine.

paving slabs

In the event that the soil is subject to swelling, then after a year concrete surface sites can be hacked, so another option should be preferred. A good choice might be paving slabs, which, due to the gaps between themselves, will allow moisture to evaporate better from the surface of the earth and the base of the parking lot will warp less.

Such tiles come in completely different textures and colors - stylized as a certain type of wood or stone. For car parking, it is better to use "granite-like" tiles.

Paving slabs are laid very easily - on a compacted crushed stone cushion 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 mallet and adheres tightly to the base. After the tile is laid, it is advisable to install a curb stone along its borders. Instead of tiles, paving stones can be used as the lining of the site, a natural stone, clinker brick.

crushed stone dumping

In the case of loose soils, ordinary crushed stone can also be used for the surface of the site. It is enough to fill the dug hole with a layer of rubble and the parking area is ready.

lawn grate

And this is already an option for lovers of environmentally friendly coatings that fit perfectly into the natural landscape. Eco-parking is a special tough plastic grill, which creates the basis for the soil in which lawn grass is sown.

The polymer grating will evenly distribute the weight of the machine over the entire area, so wheel ruts do 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 grate will not require any maintenance during the entire period of use, however, it is relatively expensive.

Canopy over the platform

Regardless of what kind of coverage you prefer for your parking lot, it is undesirable to leave it open to rain and sunlight. The modern construction market offers huge selection canopies for car parking. The canopy, which is a lightweight structure made of a steel frame and a roof - polycarbonate, slate, metal tiles, corrugated board, is very popular.

Such designs are sold already finished or they can be ordered in parts. If there is a desire, then such a canopy can be made independently. This will require support and transverse metal pipes, from which a frame is constructed with the help of welding or bolts. From above, the roof is covered with wooden boards, slate or roofing material - depending on what you have available.

Thus, parking for a car in a country house can have the most diverse look - from frankly urban (with a concrete platform and a polycarbonate canopy) to the most natural (eco-parking with a wooden canopy). The main thing is that it can protect the car from external negative factors and fit into the overall style of your site.

Asphalting today it is the easiest, fastest and most economical way to build roads and carry out repairs. For the production of new asphalt, asphalt chips formed during dismantling are used.

Requirements for asphalting roads

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

Asphalt should be laid at an air temperature of at least +5 degrees in autumn and +10 degrees in spring. Asphalting it is impossible to make at a rain, snow and other precipitations. Careful dismantling of the old asphalt pavement must be carried out before laying the new one. Only if all requirements are met can a quality result be guaranteed. BiK specialists always comply with all technical requirements, which ensures high quality of road works.

What determines the expiration date

The service life of an asphalt pavement depends primarily on the observance of technologies during its laying and use. 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 life of the asphalt can be reduced to five years, even with careful observance of all technical requirements to his setup.

How to extend the service life

Timely repair, elimination of pits, irregularities and cracks as they appear can extend the life of the road surface. Repair work do not require large financial and time costs, unlike the laying of new asphalt.

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

Employees of our company have extensive experience in road works. We always have a wide range of all necessary special equipment available, which allows us to perform any work at a high level of quality. Therefore, we offer our customers a wide range of road works.