We are all so accustomed to paved roads and sites that their absence is surprising and displeasing. Coatings of this type are present almost everywhere. Not only roads are rolled up with asphalt, but also sidewalks and sports grounds. Such surfaces are able to withstand significant mechanical loads. It should be noted that this artificial material becomes especially popular in the period from spring to autumn.
The rules for laying asphalt allow you to clearly divide all the work into several most important stages:
- preparation of the work site,
- the formation of the bearing layer (sand-gravel mixture),
- applying a coating layer (coarse fractional asphalt KZ-7, or KZ-10),
- compaction roller treatment.
Defects during asphalting and immediately after it appear in the roadway quite often. For their immediate elimination, cold asphalt can be used, which differs from the usual one in altered composition, high frost resistance and ductility. This is a functional and wear-resistant material, which is perfect for spot repair work, forming coatings on sections adjacent to the railroad, performing preventive road repair operations, etc.
- Stirring device
- Tanks in which bitumen compounds will be located,
- Devices that provide temperature control,
- Mixing mechanisms for the preparation of asphalt mortar.
“Before laying, cold asphalt of fine-grained (0.5 cm) or sand (1-1.5 cm) fraction is mixed with bituminous thickeners.”
Special surface preparation for laying cold asphalt is not required, you just need to remove excess debris and get rid of excess moisture. The breakdown in the roadway is covered with the prepared mixture and left to solidify. It is not specifically necessary to seal it, this will happen by itself thanks to the natural ramming on the site.
Types of Used Stackers
The technology of laying asphalt on old asphalt by the paver implies the use of the following types of mechanisms:
- road milling machines - devices that allow you to remove the top layer of road surfaces,
- pavers - devices used in the main stage of paving,
- rollers - mechanisms for compaction and compaction of the soil.
Pavers, in turn, are also divided into several groups.
By type of chassis, they can be:
- tracked (used mainly for the construction and reconstruction of the roadway),
- wheeled (more suitable for repair by laying the upper thin layer).
There is also a division of these mechanisms by size:
- Laying width 1-3 m: used for processing broadening strips, walkways, sidewalks,
- Laying width 2-4.5 m: covers one lane of the road,
- Laying width 2.5-7.5 m: covers two lanes of the road at once,
- Paving width 3–9 m: used for work on roads of the 1st and 2nd technical category with a two-lane carriageway.
- Laying width 3-12 m: used for work on roads of the 1st and 2nd technical category with a three-lane carriageway.
What is the minimum layer to put on the old asphalt?
The minimum layer of asphalt during paving should have a thickness of 80 mm. It must be applied at a uniform speed, without stopping. The structure of the pavement may include two layers at once, then each of them individually may not correspond to the specified value, but their total thickness should be at least 8 cm.
Technology of laying new asphalt on old
The technology of laying asphalt on old asphalt will differ depending on the nature of the damage and the degree of wear of the previous coating. For example, individual pits can be repaired with cold asphalt. If the damage is non-local in nature, it is possible to use the hot or cold milling method, in which the upper layer of old asphalt is removed, the base is textured and a new coating is applied.
Finally, an asphalt recovery method can be applied. In this case, you will need:
- carry out a thorough cleaning of the old asphalt (this will require a watering machine),
- to lay a crushed stone layer (this work is performed by a grader),
- clean the edges of the pavement and warm it,
- with the help of rollers, lay a layer of restored asphalt concrete.
When the procedure is completed, all seams and all joints are impregnated with bitumen. If the asphalt concrete blade has worn evenly and in general is in good condition, then you can "build it up". It is enough to lay on top of a carefully cleaned old layer - a new one.
The correct technology for laying asphalt on old asphalt (GOST R 54401-2011, 9128) implies the implementation of road works of any type only when dry weather and acceptable temperature.»
The asphalt layer laid in the rain can immediately be considered defective.
How much does it cost to lay per 1 m2 of new asphalt on the old
To accurately calculate how much it costs to lay asphalt 1 m2, you need to take into account the cost of consumables and the work itself. Specific figures may vary depending on the region or the particular technology chosen. However, the average cost per square meter of asphalt with paving ranges from 400 to 1000 rubles.
What documents are needed for repair work?
Like any other type of construction activity, repair work is accompanied by relevant documentation.
Laying agreement (sample):
Territory asphalting agreement (sample):
We must not forget that any construction work must be completed with the complete removal of garbage. Also, do not save asphalt concrete too much, otherwise you will soon have to start working again. Compliance with all technological requirements will extend the life of the road surface up to 5-10 years.
What is asphalt made of?
Before talking about laying, you need to figure out what the asphalt coating consists of. Asphalt is a mixture of bitumen with bulk materials: sand, gravel or gravel. Depending on the purpose of the pavement, the percentage of components may vary. For example, it makes no sense to use crushed stone for a parking area near the house, since it allows you to withstand high pressure, which is necessary to cover public roads and highways. For ordinary paths and car areas, it is recommended to use up to 10% of gravel due to the lack of a large load on the coating.
Bitumen refers to tar-like products that result from oil refining. It is a binder component of the asphalt mix. The amount varies from 2 to 11%, depending on the purpose of the road surface. The higher the load, the more bitumen is contained in the asphalt.
Sand acts as a fine filler and allows you to evenly distribute the external load on the canvas. When preparing asphalt, only pure sand is used, since the final indicator of the strength of the canvas depends on this.
Crushed stone or gravel
As mentioned above, crushed stone is used to increase the strength of asphalt to external loads. If it is planned to move more than 5 tons along the equipment site, for example, when organizing the access of trucks to the construction site, the presence of crushed stone up to 15 mm in the asphalt is a necessary condition. Such asphalt will cope well with high tire pressure.
In the asphalt for pedestrian walkways, gravel up to 3-5 mm is used, which is an excellent shock absorber and filler.
Hot and cold asphalt paving
The most common method is hot laying, since this method provides a reliable and durable coating that can withstand loads up to 15 tons without deformation, which cannot be guaranteed by other types of road surfaces. Also, this method is considered the most cost-effective, if you take into account large volumes.
It is worth noting that the technology of hot styling involves working with a mixture of high temperature up to 120 ° C, which is quite dangerous in the home!
High temperature is necessary to prepare a homogeneous mixture, otherwise the reliability of such a coating will be of poor quality. Among the pluses, durability should be noted, due to the high degree of resistance to environmental influences. Among the shortcomings - in extreme heat, asphalt can become deformed and become environmentally hazardous.
Cold asphalt which is a mixture based on polymer-rubber bitumen is gaining popularity. It is mainly used for repairing pits, cracks and potholes on roads, as well as for refining personal plots. It is an environmentally friendly material since it does not contain solvents and plasticizers. A wide temperature range allows you to use it in extreme heat up to +40 ºС and severe frost up to -20 ºС.
Below we will look at how to properly lay asphalt with our own hands.
Hot Paving Technology
The following materials and tools will be required for hot laying of asphalt: a metal barrel, an ax, a shovel, a mop, a hand roller weighing 100-120 kg or a vibrating plate, a hand rammer, bitumen, sand, gravel or gravel.
- Asphalt needs to be laid in dry weather. The laying surface must be prepared in advance. The top layer of the earth needs to be removed, about 4-5 cm. Pour and sand a layer of sand, then fine-grained gravel in its place, to create a stable pillow.
- Next, you need to melt the bitumen, placing a metal barrel on a stone base in which fire will burn. Bitumen needs to be chopped into pieces with an ax. The smaller the pieces, the faster they will melt them. It is best to mix with an old shovel, since after laying asphalt it will become unusable. All work is best carried out directly near the place of laying so that the asphalt does not have time to cool down during its transportation.
- When the bitumen melts and boils, you need to start adding sand and gravel. You need to add gradually, then it will be easier to mix this mixture.
- Then with a shovel, you need to start spreading the mixture on the prepared surface. A shovel is excellent for these purposes. To level the layer of asphalt, you need to use a wooden mop. To increase the plane of contact with it, you can nail a board.
- After leveling, you need to use a manual roller for rolling. The drum must be moistened with water! If there is no skating rink, then a vibrating plate or manual tamper can be used. After finishing work, the coating must be allowed to stand for at least 6 hours.
The result is a durable coating that can easily withstand a car.
DIY asphalt paving
The technology of laying cold asphalt is much easier and simpler than hot. The mixture is already sold ready-made in convenient bags and buckets. The following tools will be required for installation: a manual skating rink, a vibrating plate or a manual rammer, a mop.
- First you need to prepare the surface. Remove the top layer of earth 4-5 cm and pour a layer of sand, then crushed stone and compact everything well.
- Pour the first layer of the mixture, smooth with a mop and roll with a hand roller or vibrating plate. If you do not have these funds, then you can do with a manual tamper. Then you need to pause 10-15 minutes and lay in this way the second layer. Good performance indicators show three layers of asphalt.
- After 24 hours, the coating is ready to use.
When laying cold asphalt, it is important to compact it in order to prevent water from entering the cracks and then such a coating will serve for a long time.
Marking and signs
Drawing lines and signs with thermoplastic or paint will mark the asphalt surface and indicate the necessary warnings. For example, on the site in front of the house you need to mark out parking spaces for cars. Or put a warning sign about the danger to drivers. For these purposes, thermoplastics is most suitable because it is wear-resistant, has good adhesion with asphalt and has a long service life. It is necessary to apply thermoplastic using special equipment, since it is required to constantly maintain a high temperature in the boiler and thoroughly mix the plastic mass.
If it is not possible to use specialized equipment, then the following recommendations should be observed:
- The asphalt surface must be dry and clean, then the plastic will hold firmly on the surface.
- The melting temperature of plastic is in the range from 140 to 180 ºС. After the plastic has melted, it must be constantly mixed to avoid clots.
- For applying thermoplastics, you need to use ready-made forms that will allow the plastic mass to harden on the asphalt.
- Thermoplastic cooling time is only a few minutes.
We examined two ways of laying asphalt, thanks to which you can get a high-quality and durable coating. The first method is beneficial when paving large areas. And the second - for the arrangement of a private household. In any case, a properly laid asphalt pavement will withstand heavy loads and will last a very long time.
What types exist
Currently, only two types of coatings are used:
As for the paving temperature, asphalt compositions are divided into two types:
- Hot coatings. They are laid at temperatures above 140 degrees. This requires special equipment. Hot asphalt pavement is highly durable, so it is used for laying roads, city streets and squares.
- Cold asphalt. This type of mixture is also called warm, and it is prepared using bitumen, which has a reduced viscosity. Cold material is laid at a temperature of 80 to 120 degrees. Asphalt pavements of this kind are most often used in yards, on playgrounds, sidewalks and other places that are not subjected to heavy loads.
All asphalt mixtures are divided into three classes according to the grain size of mineral components.
The first class is large grains. The largest of them can reach four centimeters. Material of this caliber is suitable for laying tracks. It is able to withstand the movement of a large number of trucks.
The second class is medium grains. Their largest size can be 25 millimeters. Such material is used to improve pedestrian streets and squares.
The third class is small grains. Particles of the mixture in this case do not exceed a size of fifteen centimeters. The fine fraction allows you to achieve a tight fit of the grains to each other. Therefore, during tamping, the surface is perfectly flat. This class of coating is suitable for the refinement of yards and sports grounds.
Any coating has its advantages and disadvantages. Asphalt is no exception. Its advantage can be considered the possibility of using specialized equipment in the installation process. Note that building concrete, for example, is laid only by hand, which is incredibly difficult.
The main disadvantage of this artificial material is its strong smell. And all because the mixture contains bitumen, which, under the influence of high temperatures, begins to smell strongly. This causes some discomfort.
If we talk about asphalting, then this process is quite complicated. It requires strict adherence to technology. Note that for each individual stage of laying there are standards. If all the rules are followed, then the finished coating will last for many years. It is also worth adding that in the process of laying a variety of machinery and equipment is used. Therefore, it is not enough just to attract experienced specialists and study the technology in detail. You must also have a license confirming that the company has the right to provide appropriate services.
In addition, the contractor must know how to correctly calculate the thickness of the future coating, how to perform marking, to perform all the necessary work. He is also required to guarantee quality. This is very important, because each of us knows very well how domestic companies like to save on this process. As a result, the road surface crumbles in just one season.
So, asphalt laying is a multi-stage process. Performing it is not easy, especially in the cold season. It is important to show extreme accuracy and scrupulousness. If the standards are violated, the material consumption will increase significantly, and the coating will become unusable faster.
But first, let's figure out what the asphalt coating consists of. And its components include the following components:
- Bitumen and bitumen emulsion.
- Mineral powder or stone flour.
Each of these components is taken in strictly defined proportions. Ни в коем случае нельзя заменять чистый щебень и песок продуктами камнедробления.
Рабочий процесс начинается с того, что местность тщательно размечают. Асфальт должен быть на одном уровне с землей. Именно поэтому вначале подготавливают сам грунт. The most loose part is removed using a bulldozer. It turns out like a bathtub for laying material. Its bottom is covered with sand, which is compacted with a vibratory roller and covered with special material. It is called geotextile. Its function is to prevent gravel from falling into the sand layer. Due to this, the level of strength increases.
Asphalt itself is laid either on a rigid concrete base or on a crushed stone pillow. For its preparation, crushed stone of three types is used. At first, the largest species falls asleep, and then the medium and small ones. As you add each of the layers is also rammed with a roller. When the pillow is ready, it must be poured with an emulsion of bitumen.
The final stage is the laying of asphalt, which is thoroughly mixed with fine sand and stone flour. This mixture is heated to the desired temperature and layered. Each of them should be approximately seven centimeters thick. In the process of paving use an asphalt paver. This serious technique is equipped with many sensors and its own computer. Upon completion of the process, the finished coating is again watered with a bitumen emulsion.
Note that technology may vary. It all depends on what type of material will be used in the process. For example, hot asphalt is laid quite differently than cold. Updating existing coverage is also performed using a different technology. In this case, there is no need to make a new foundation. It is necessary either to simply remove the old coating, or to ensure high-quality adhesion of the old and new layers. Note that you cannot lay asphalt in rainy weather. This will lead to too quick cooling of the composition, which will prevent it from being properly sealed.
If the laying of asphalt will take place in the winter, then it is necessary to use warm asphalt concrete. Its main difference lies in the content of special additives. Thanks to them, laying of asphalt in the winter becomes possible.
As for the laying of cold asphalt, it is usually used for patching. The fact is that a cold coating achieves the required strength due to compression. In other words, the finished mixture is simply laid on the desired site and rammed using heavy equipment. At the end of the repair work, the traffic is completely restored, which also contributes to an increase in the strength of the laid mixture. Cold asphalt is good in that it can be laid in any weather conditions. Moreover, this technology minimizes the amount of waste. The material that remains can be used in the future.
On defects in asphalt pavement and methods for their elimination
Now let's look at what defects can appear on an asphalt pavement, we will understand the reasons for their appearance and how to eliminate them.
- Short waves repeating every half meter. In this case, most likely, the composition is unevenly fed to the stacker screw feeders. As a result, the pressure of the screed on the surface is constantly changing. To eliminate the defect, you need to carefully examine the batteries of the paver and the smoothing plate itself. It is also necessary to pay attention to the temperature of the composition and its stability.
- Waves of a long type. Such a marriage occurs due to fluctuations in the composition and its temperature. Also, the reason may lie in sudden changes in the movement of the roller. In addition, this flaw may reflect a roughness of the foundation itself. The defect is eliminated by controlling the operation of stacking mechanisms and the quality of the working composition.
- Tears in the middle of the laid layer, along its edges and over the entire surface. Here, most likely, the paver himself is to blame, or rather his smoothing plate. Also, deformation of the coating can occur due to the low temperature of the working composition and the presence of extraneous components in it. Gaps can be eliminated by strictly controlling the operation of stacking equipment. Single tears are patched only by falling asleep hot mixture directly in front of the road roller.
- Uneven surface texture. This defect appears due to the fact that the composition exfoliates, its temperature decreases, or it simply goes wrong to the stacker. To eliminate the defect, you need to determine the cause of its appearance and monitor the operation of the paver.
- Cracking. This defect can manifest itself at the very beginning of the rolling process. The problem may lie in the excessive plasticity of the composition or its high temperature. Less often, the surface cracks due to the large temperature difference between the mixture and the base. In this case, the asphalt composition is checked and adjusted, the sealing mode is corrected. Replacement of road roller links may also help.
- Bituminous spots on the surface. This flaw arises at the very beginning of operation. This can make the coating more slippery, especially if it is raining. The cause of this defect is too much bitumen in the mixture, its separation, the presence of water in it. It is possible that the base itself contains too much bitumen. This drawback can be eliminated by controlling the level of moisture and bitumen in the mixture, changing its composition. In extreme cases, oily spots can be sprinkled with fine sand.
- Low quality of seams of contact of strips. Such a nuisance can occur if you do not follow the installation rules. Naturally, it is eliminated by strict adherence to asphalt paving technology. Also, experts recommend warming up cold commissures with gas burners, and then rolling them up with a roller.
- Unequal layer thickness. This type of marriage occurs either because the screed is not adjusted, or because the stacker himself drove too fast. In this case, you must adjust the operation of the asphalt machine.
- Longitudinal cracks. This kind of flaw arises from the fact that the bottom layer is poorly tamped. When the roller moves, this layer moves. As a result of this, cracks appear. The defect can be eliminated only partially, and then the mixture has not yet cooled.