What is asphalt? What is the traditional sidewalk asphalt?
Asphalt paving contractors use asphalt of all types to strengthen roads is mainly composed of two components: bitumen and mineral chips. Asphalt bitumens are available in various grades. Features of production technology Natural bitumen usually occur in the form of lenses near oil deposits. However, in industry and road construction, this second type of material is used more frequently-is artificial. Make such bitumen from refined petroleum products. It is usually tar and an extract of selective oil refining. Composition of asphalt and its varieties In addition to bitumen’s, mixtures intended to cover the road may contain components such as sand and crushed stone. At first, we use sand asphalt. Occasionally crushed stone is also added to the mixture. This is a very common type of coating. Such asphalt concrete is called rubble. Also, the material of this road may be made using gravel. In this case, crushed stone and mineral powder are added to the mixture. This kind of asphalt is called gravel. Depending on the purpose of the mixture, the proportions of all of these components can vary. Therefore, the sidewalks use asphalt made of fine sand and crushed stone. The lowest layer of the roadway is usually made from a mixture of slightly different compositions. In this case, asphalt is made using only very large crushed stone. Smooth asphalt is poured in the top layer of the road. Its structure contains small fractions of crushed stone.
Bitumen asphalt mark
Thus, the type of filler used affects the strength of this type of material and thus its application area. However, the composition and quality of asphalt are not very dependent on the grade of bitumen mixed in with it. Usually, special materials of this type are used for the production of mixtures of this type. It is called Road Bitumen and is marked with the letters BND. The main parameter in which this substance is classified is the temperature system
Under certain conditions, bitumen begins to melt without exception. Depending on when this happens, you can use the material in specific areas of that country. In order to determine the conditions under which this particular bitumen is used for asphalting, the markings must first be examined. The numbers in it indicate the viscosity range of this material. Currently, five types of road asphalt are used in the manufacture of asphalt: BND 40/60, 60/90, 90/130, 130/200, 200/300. The higher the climate, the more viscous the pavement is produced
Of course, asphalt bitumen must be present in sufficient quantities. Too much of this material in the preparation of the mixture is usually not used. Hot pavement compounds are not massive and should not be broken. However, without sufficient bitumen, asphalt starts to develop various types of harmful processes over time. Water penetrates it and freezes and breaks during the winter.
Main characteristics of BND
In addition to the viscosity, asphalt bitumen is Ductility this indicator is determined by the distance that can be drawn into the thread without breaking the bitumen. The larger it is, the stickier the mixture is. Road asphalts usually have a ductility on the order of more than 40 cm. The BND requirement for this indicator is set at a temperature of 0 ° C. Deformation characteristics. In determining bitumen suitability for asphalt production, attention is also paid to properties such as elasticity, creep, plasticity, brittleness and the like. It is those properties that determine the deformation properties of this material. Once the bitumen is heated, it should not change much.
Liquid formulations under construction
Asphalt bitumen usually has a very high viscosity. However, when pouring the coating, a liquid variety of this material may be used. Mainly used to prolong the season of road construction. A certain proportion of liquid bitumen is added to the viscosity. As a result, coatings at low temperatures do not cure very quickly. Liquid bitumen is made viscous by adding a distillate fraction. Medium viscosity materials are also used when performing repairs. Used to process cards that have already been cleared. In this case, the bitumen consumption rate at the time of laying asphalt is not so large.
What supplements are included in BND?
Various additives can be used, in the production of road asphalt. These are needed to change certain characteristics of this document. For example, in the manufacture of cold asphalt, bitumen is used, which consists of modifying components. As a result of their application after solidification, the coatings do not crack when cold and do not melt with heat. When using a MAC additive, the bitumen’s acquire their final properties more quickly.
What will be added to asphalt bitumen? If colored mineral powders are used in the production process, a very interesting variant of this material is obtained. From this bitumen, very beautiful asphalt was found. We lay in park and bicycle way and use for marking.
Asphalt has deep historical roots and was already known to the ancient Egyptians and Phoenicians. However, unlike our time, asphalt was intended for a completely different purpose than the covering of ancient roads. To understand what naturally occurring asphalt is, mountain natural asphalt contains 75% bitumen. Egyptians using asphalt used a corrosive composition to preserve the pharaoh’s mummy. Abysena recommended asphalt for treatment of the disease by analogy with the mummy. Practical Phoenician and Indians infiltrated their ship and canoe with asphalt compounds. It was hardly known that the Dead Sea was called the asphalt sea until the twentieth century because this mass of natural material floats on the surface.
I will be happy if the knowledge is to help anyone about the asphalt and bitumen.