With high -quality sealing, using modern sealing equipment, coarse -grained asphalt is also used for a single -layer road surface, which in its qualities is not inferior to two -layer asphalt. The main properties and characteristics of coarse -grained asphalt.1. The gravel used for asphalt has a large fraction of 40 mm.2. The volume of the remaining pores in the asphalt after its rolling is about 5–10%.3. The temperature during the shipment of ready -made asphalt should be at least 150 ° C to consumers.4. In the finished mass of asphalt, the amount of crushed stone should be about 60%.The main property of such a material as the asphalt is coarse -grained is its high strength. This composition of asphalt withstands large dynamic and static loads. But the use of large crushed stone, in addition to increased strength, has one drawback – This is a great porosity of the laid asphalt. Moisture penetrating through pores has the ability to destroy the asphalt coating over time. Especially for frosts in the autumn period, when a sharp change in temperature occurs often — at night minus, and during the day plus. The addition of crushed stone of a small fraction and special minerals reduces the porosity of the asphalt, but still completely getting rid of the pores is practically not possible. The use of coarse -grained asphalt. Coarse -grained asphalt, having high strength, successfully transfers large loads arising from the wheels when the vehicle movement on the ground canvas of the road. Therefore, it is most often used as the lower bearing layer in asphalt of the road in two layers. Asphalt made with a crushed stone of a large fraction using modern technologies allows it to be used not only during the construction and reconstruction of roads. They are successfully asphalt with parking sites and territories around large shopping centers, courtyard and park paths and other squares. Road surface device. The main feature of laying any asphalt water, but especially coarse -grained, is to observe the temperature of the layered asphalt mixture. It should be at least 150 ° C. Otherwise, the stacked mass of asphalt can delay the components of its ingredients. And this will cause the loss of certain properties that are necessary for high -quality styling and the normal function of the road surface.