It is difficult to imagine a modern metropolis without good smooth asphalt. After all, high-quality roads are one of the main indicators of a high standard of living and development of the city. Every day, hundreds of thousands of pairs of legs and even more car wheels walk and ride along boulevards, avenues, roads, driveways, not noticing what is under them. And asphalt, by the way, is one of the most popular road surfaces.
Therefore, it would be fair to understand what is asphalt. What happens and how is it laid?
What is asphalt
Asphalt is a building material obtained by mixing various bitumen and mineral components. Their ratio may vary depending on the standards used in the production of a particular type of mixture.
It’s most common for a person to see how asphalt is used in the construction of roads, but he also has other areas of application. For example, it is part of all kinds of varnishes, adhesives and putties.
Types of asphalt
By type of origin, asphalt can be natural and artificial.
Natural asphalt is composed of hydrocarbons. It features a high level of bitumen content. They are in it, as a rule, at least 60%. They learned to extract and use this material in the economy in ancient times.
The most famous natural deposit of this material is Peach Lake Lake on the island of Trinidad. It consists entirely of pure liquid asphalt.
The “colleague” of Peach Lake is considered the Dead Sea. Layers of asphalt periodically floated to its surface. However, for more than half a century, no such cases have been reported. The last documented fact of the rise of asphalt mass weighing about a ton on the sea surface dates from the sixties of the XX century. It is believed that such asphalt, extracted from the Dead Sea, has the best qualities. It was mainly used in the chemical and paint industry.
Artificial asphalt is produced in factories. It is a mixture of crushed stone, sand, mineral powder and bitumen. There are a great many varieties of artificial asphalt: liquid, cast, dry, sandy, soft, rubber, and others. In this publication we will talk more about dry and liquid asphalt.
Liquid asphalt - what is it?
This is a sticky natural substance of black color, which has a number of physical properties. It is formed as a result of the processing of crude oil, when all light fractions are isolated from it. For example, as a result of the production of gasoline. Liquid asphalt is used as a binder in the manufacture of asphalt mixtures. It is also known as bitumen.
On the basis of bitumen, some varieties of liquid asphalt are also produced at the plants, adding various substances to it. In particular, colored asphalt. It is widely used in landscape design, it is believed that such asphalt allows you to recreate almost any texture and surface color. If you use a stencil when pouring, for example, in the form of paving slabs, then the final coating will acquire a characteristic relief. Liquid asphalt has increased wear resistance. In addition, when carrying out the necessary preventive work with the help of special tools, you can “update” the coating without completely replacing it.
Manufacturers claim that even an amateur can fill such asphalt, following simple instructions.
What does dry asphalt consist of?
Dry asphalt is often called cold. This is because dry asphalt is such a mixture that can be laid at fairly low, even below freezing temperatures. The main thing is that the material itself should not be colder than +10 ° C. Temperature conditions are one of the main advantages of this type of coating. Dry asphalt consists of filler, bitumen and various additives that give it some properties.
Among the disadvantages are the high cost of this type of coating (about 4 times more expensive than hot) and its “amorphous” nature. That is, even after rolling, after some time, it can be deformed, therefore it is recommended to be used in places where the load on the road is distributed evenly: on sidewalks, highways, and when patching holes. But near pedestrian crossings or stops of public transport, it will quickly become worthless, since vehicles in these places either stop or gain speed again.
Asphalt laying process
A significant advantage of dry asphalt is that it is sold in bags or plastic buckets already ready for use. It can be laid even in wet weather, and this requires a minimum of road equipment.
As a rule, laying dry type asphalt includes six stages:
- Removing a worn coating.
- Cleaning the site of dust and debris.
- Warming the ends (especially when it comes to patching pits) at the installation site.
- The distribution of a layer of sticky bitumen on the surface.
- Laying material, leveling the surface.
- Vibration plate compaction.