Requirements to road asphalt-concrete coatings

The phenomenon of road phenomenon has a unique place in the development of humanity and contributes to the improvement of living standards. Roads are ranked first among all transport networks used on the ground according to their "compactness".

Highway - motorized vehicle engineering. The highway is divided into international, state (local) and local roads. The International Highway includes roads linking countries, large industrial centers and major economic significance. Public roads are roads connecting major industrial centers, major railway stations, pristan and others, and local roads include regional, village, community roads. The motor road engineering consists of the following elements: ground floor; roadbed; carriageway; roadside; sun'-smell and linear structures and other equipment. The highway consists of natural or soil extensions, basements and coatings. The base (middle layer) is sand, gravel, stone, shale and shah. material is made from 133. Depending on the importance of the motorway, the following types of coatings are to be operated: a) sandy loam on the ground, low-grade coatings of gravel; b) Coarse fibrous or groats; c) lightweight coatings on gray stone and gravel; g) capital coatings such as asphalt concrete, cement concrete. The width of routes allows the car to run in two or more rows. The width of one line is 3 m wide. The width of the margins is 2 to 2.5 m. Sometimes the middle of the road is planted in green spaces to ensure the convenience of movement. In the road construction, artificial structures (tunnels, bridges, base walls, protective corridors) will be built. The highway is equipped with water drainage and drainage equipment. Traffic signs, indicators, protective equipment and traffic flow control devices are installed to ensure traffic safety. Also, the automobile will be equipped with technical service stations, fuel stations and other facilities. According to world standards, highways and railways will be divided into five categories, divided into two.

The procedure for the construction of asphalt-bottet coatings is as follows: preparation of mixing plants, preparation of bedding, transportation of asphalt-bpone mixture, spreading and condensation of the resulting layer. The asphalt bleet mixture should be transported to the workplace in motor racks, the distance to the transport should be such that the hot mix should not be less than the permitted temperature in the dispensing compartment.

Welded asphalt pavement coatings are made in dry spring and summer, at which the air temperature should be below + 5ºС and in autumn at + 10ºS.

Construction of asphalt-concrete coatings is usually carried out in two shifts. It is recommended to lay the top layer during the daytime. In the evening shift the machines, equipments, aggregates and automatic maintenance technics are provided.

The pavement of the asphalt concrete pavements is accomplished through a well-leveling and tightening of each layer: the high level of flatness and density of the bed and floor: the coating on the level of the standard; reducing the number of transverse connections, and strict control of production.

Ground flooring in winter conditions, if groundwater level is close, row height is higher than 3 m where the roadbed is carried out in 2 years after foundation of the soil slab.

The asphalt-bottone coating is smooth and smooth, with the use of asphalt machines which automatically controls the given plane and the thickness of the coating.

Asphalt-bottetone coatings are placed on a dry, clean and free surface.

In order to have a good adhesion of the coating, the base is purged of dusty dust through mechanical cutters, compressed air or other applications before moving the asphalt concrete. The humidified base is heated up to 150 + 200 ° C with heated sand and heaters. 41 When required, the substrate on the base or asphalt-betone coating surface is treated with a bitumen emulsion or liquid bitumen 3-5 hours prior to the foundation of the asphalt concrete pad.

Depending on the surface of the substrate on the substrate or asphalt concrete surface coating, it is 0.5-0.3 per 1 m2 and fluid bonding ratio of 0.2-0.3 dm3 / m2. If you use a 60% bitumen emulsion for this purpose, then the consumption will be 0.6-0.9 to 0.3-0.4 dm3 / m2

If the coating is laid on organic base material, ie, the top layer on the layered base layer and the new layered substrate, it may not be possible to process the surface binding.

Mechanical groups for the construction of asphalt-bottet coatings are: selfpropelled asphalt, motorized cages, auxiliary machinery and necessary manuals

(road broomsticks, mobile bitumen boilers, heaters, devices, lighting power stations, etc.).