Asphalt pavement: what it is, what formulations are made,

Historians argue that the first mention of something similar to asphalt appeared in the 6th century BC in Babylon. But the technologies of those times were not reliable, plus unnecessarily expensive, as a result, such roads were forgotten until the 20th century. Construction of asphalt pavements in Russia began in 1928 and to this day it is predominant.

What it is

This composition is used everywhere, starting with the laying of federal highways and ending with the arrangement of urban areas and garden paths in private construction.

According to GOST and SNiP, the asphalt concrete pavement device may be different.

But the overall composition of the mixture, for more than 100 years, remains unchanged:

• First of all, bitumen enters as a binder..
• Be sure to some extent there is sand and large mineral fillers.
• The list is completed with various mineral or synthetic additives..

In those days, when the composition was developed, natural bitumen was used, but since it is not very natural in nature, an artificial analogue was synthesized based on refined petroleum products, which is still successfully used by road workers all over the world.

Sand is taken career, as for coarse filler, along with various types of rubble for concrete, crushed rocks and some crystallized slags are widely used.

Natural mineral or synthetic additives are used to increase certain useful properties of the coating. In particular, increased frost resistance, road grip, viscosity and much more.

What formulations are available

The range of species presented is quite wide, depending on the percentage of the components, as well as on the additives used, the experts divide the asphalt into the following types.

1. For the arrangement of sidewalks, garden paths or the inner space of urban courtyards, sand compositions are used.
2. Fine-grained compositions cover the city streets with medium and high traffic intensity.
3. Coarse-grained asphalt is used as the underlying layer in multi-layered laying technology.
4. Polymer-bitumen coatings are used for the installation of bridges, bulky parking lots or road junctions. They have increased strength and durability.
5. Crushed stone-mastic types of asphalt are considered the most robust, they are laid by federal highways and high-speed autobahns with increased transport load.
6. For stadiums, running or bicycle lanes, as well as other sports facilities, there is a rubber-bitumen coating.

Asphalt production at home

Making pavement is considered to be a difficult and inaccessible case. But, nevertheless, there are enthusiasts who are ready for experiments. Of course, such compositions are not designed for the federal highway, but at the dacha it is quite realistic to prepare such asphalt with your own hands.

Tip: from experience we can say that the mixture prepared in an artisanal way, of course, is suitable for arranging a garden concrete path, but more often it is used to repair potholes on an already finished surface.

Classic recipe

For the preparation we need the usual river or quarry sand, tar or bitumen and crushed stone of small fraction. From the equipment will need a metal barrel and a bucket.

It is better to cook asphalt on a fire, as using gas is unsafe and expensive.

• Initially, we fall asleep rubble with sand in a 2: 1 ratio and mix well. All this should be filled with water and hung over the fire.
• At the same time we are preparing a bitumen base. To do this, we take a metal bucket and heat the bitumen in it to a boil, synthetic polymers can be added as a plasticizer, but it is cheaper to use shampoo or any detergent.
• When the resin warmed up, and the water in the barrel with rubble also boiled, they need to be connected. Water is needed to ensure that crushed stone with sand does not heat up above 100? С. Next, this broth should be stirred, keeping boiling until all the water boils away. While the solution is hot it can be poured.

Important: be careful, at 80? With bitumen melted, and at 100 - 120? With it boils. But already at 170? C bitumen can ignite. Actually to prevent such a fire, we use water.

Using old pavement

Dismantling asphalt pavements and foundations can be a good material for making new asphalt.

The technology partly resembles the previous version, but with some amendments.

• The asphalt concrete pavement itself is dismantled using the old-fashioned method, using a sledge hammer and other percussion instruments. Only the upper layer of asphalt bound by bitumen is used, the road cushion can be left alone.
• Old pavement is broken into pieces with a fraction of not more than 40 mm. For 100 kg of old asphalt 10 kg of bitumen is taken.
• After that, the ground substance needs to be filled in with water and boiled in a barrel until melted. Next technology repeats the above option. Heated bitumen combines with molten asphalt and water is evaporated.

Cold asphalt

The above two methods are well suited for economical repair of damaged asphalt in the yard or near the yard. If you need to cover the area with a large square, then we recommend using cold asphalt.

This coating appeared on the market of our country about 5 years ago. The principle of operation here is similar to the widely known cold welding. Modified bitumen is used for the binder, so it can be laid even at sub-zero temperatures. The instruction is on the package.

The only disadvantage of this material is a significant price. But, as it is known, asphalt from the factory is released hot and must also be stowed hot. Therefore, for remote locations, cold polymer asphalt is the only alternative.

Important: when repairing the pavement, the problem is a high-quality joint device in the asphalt concrete pavement. Polymer-based cold asphalt solves this problem completely, as it fits securely with any bitumen-based compound.

Paving rules

Construction of asphalt pavement is a responsible matter and it’s not so important whether you install it yourself or hire professionals. Laying and acceptance of asphalt concrete pavement is carried out according to SNiP 2.07.01-89, as well as a number of state standards.

Only a specialist can understand these documents, therefore we have outlined the main provisions of these norms and rules in a more understandable language.

Preparatory stage

Any work begins with markup. You need to clearly decide where the asphalt will be laid. Where the curb will be mounted, and how it will be. It is also very important to take care in advance that the drainage, drainage system and drainage system be installed.

All work on the installation of underground communications by this time should be fully completed. If you are arranging the parking area or access roads to the office, it is better to know in advance where the city communications are going, since, if necessary, the municipal services will disrupt your coverage and may even impose a fine.

Above it was mentioned about the types and purpose of existing types of asphalt. So, at the stage of preparation, you need to choose what kind of material you are going to stack.

Important: the estimate for the device of asphalt concrete pavement should contain not only data on the cost of the material and the scope of work. It would be useful to include transportation costs in it, as well as leave a column for unforeseen expenses, such as permission to work from the relevant official or service.

If a footpath or a platform with occasional passage of passenger cars is laid, a black-gravel cushion can be made up to 15 cm thick. The thickness of the asphalt concrete pavement will be between 4 and 5 cm.

If you equip gas stations or any access roads, along which, with high probability, heavy equipment will periodically pass, then in this case the gravel cushion thickness will be about 25 - 35 cm. Plus asphalt itself will be laid at least 2 layers.

After marking the arrangement of the so-called trough or pit for the road begins. In the city or in private construction, as a rule, roads and platforms are made at about the same level, therefore, the ground must be chosen completely for the whole thickness of the “road pie”. Federal highways are being equipped with a somewhat different technology, but we will not dwell on it.

When the ground is chosen, the whole site should be well tamped, it is done with a roller or vibrating plate. Pay attention to the presence of trees nearby, the roots may eventually break the asphalt, so, if possible, it is better to remove them immediately. Although the price of works will be slightly increased, we advise you to cover the ground with geotextiles so that the vegetation does not penetrate the floor.

Important: at this stage, the curbs are set, they play the role of a formwork for the “road pie”. If at laying of paving slabs the border is made below the level of the road, here, on the contrary. In this regard, it is necessary to immediately plan drains for water drainage.

Now you can start dumping pillows from rubble. For walkways with a cushion thickness of 10–15 cm, 1 layer of crushed stone of a fraction of 30–40 mm is sufficient. More powerful bases are stacked in several layers.

The bottom layer is used for drainage in case of rise of groundwater, it is poured with large gravel with a fraction of 40 - 70 mm. The next layer with a fraction of 20-40 mm will be responsible for evenly distributing the load on the base of the road.

The final layer of dumping is made of fine gravel with a fraction of 5-20 mm. He will also be responsible for the distribution of the load, but in addition he will turn the pillow into a dense, monolithic structure.

All layers must be tightly tamped. For serious surfaces, road rollers weighing from 2 to 10 tons are used. Each ball dumping compacted separately, the roller must walk on it at least 5 times, plus in modern road rollers is a function vibropress, which increases the efficiency several times. In the process of tamping, the surface should be regularly watered.

Tip: in the process of tamping should immediately take into account the angle of the road, on average, it is about 1? on 1 running meter. To do this, periodically check with markup or data leveling.

Asphalt laying

After the tamping of the pillow, you can proceed directly to the laying of asphalt. As mentioned earlier, for sidewalks and localities, it is enough to lay a fine-grained composition with a layer of up to 50 mm. Heavy road rollers are also not required, you can get by with a light roller or vibrating plate.

Note! This type of coating according to SNiP is not recommended to lay in places for recreation.

More serious objects are being put out in 2 layers. In this case, the lower layer is laid with coarse-grained asphalt at a level of 40 - 50 mm. A fine-grained composition is applied almost immediately to it, which in most cases is finishing.

At present, technologies have been developed, according to which a reinforcing mesh of polymeric materials should be laid between layers of hot asphalt. As a result, the durability and strength of such a road increases significantly. This technology is used when laying the federal highways and roads with increased load.

Important: the restoration of asphalt pavement is most often done with the help of hot bitumen. Although GOST should be performed thermoprofiling asphalt pavements. This procedure involves pre-heating the roadway to a depth of 2 to 5 cm.

The mixture should be delivered hot to the object, as a rule, it is brought by dump trucks with a carrying capacity of 7–20 tons. After that, asphalt is manually or machine-evenly distributed along the road plane, observing the slope. An average of 10m? the roadbed consumes 1 ton of asphalt with a thickness of 40 mm.

Construction of asphalt pavement is a meteorological process. In the cold season, that is, at temperatures below +5? C, it is not recommended to perform work at all. Plus, during rain or in wet weather, the laying quality is significantly reduced, as the composition is moistened and cools faster.

Conclusion

We outlined the general basic principles of high-quality laying of asphalt, but science does not stand still and technologies are complemented and improved. In the video in this article, you can consider the process of laying asphalt in more detail.