Guests on the pavement. How is asphalt paved? Asphalt in one layer

Asphalt road should provide the necessary smoothness of the road.

This article describes what an asphalt road is and in what cases the use of single-layer asphalt is justified.

Asphalt is a mixture of various resins and bitumen - asphalts with a filler - sand, gravel, crushed stone and various additives that change the properties of the finished mixture. Due to the large number of bitumen, in the heated state, asphalt concrete is plastic, well compacted, after solidification it acquires strength and wear resistance. Properly made asphalt roads have been around for decades.

Asphalt should have a minimum slope of 2% to avoid the formation of stagnant puddles that contribute to its degradation. This slope is set by a mound of crushed stones to also remove surface water along the perimeter of the foundation. If it is impossible to avoid asphalt, you should consider installing a drain to receive and direct rainwater into a storm sewer or ditch.

The compaction of crushed stone backfill is carried out using a reversible vibrating plate, which uses eccentric rotating loads to provide impact force and speed. A jumper or leg jumper that uses a lower frequency but a higher height for compaction, the impact force of the rammer is greater than the force of the vibrating plate. The compactor uses vibration as well as static force to seal foundation units.

Asphalt mix is \u200b\u200ba mixture of various resins and bitumen.

How is asphalt paved?

Asphalt is the top pavement. In order for the asphalt to serve for a long time, it is necessary to prepare a quality foundation. Crushed stone of different fractions, brick fight or concrete are used as the base. The base provides drainage of rain and groundwater and the distribution of pressure on the coating over the largest possible area. Ground unevenness of the soil is leveled to exclude the formation of knolls and pits. Thickness asphalt pavement directly depends on the basis and expected operating conditions. If the base is made of crushed stone or brick, then the thickness of the asphalt will have to be increased, because the compacted crushed stone does not have the necessary rigidity. If concrete is poured over crushed stone over the base, which provides the necessary stiffness of the coating, then the asphalt layer can be made smaller.

The minimum thickness of asphalt after compaction should be 2 inches. Prior to compaction, the asphalt layer should be between 5 and 3 inches. Basically, there are two types of asphalt for residential floors. The number of stones is greater, asphalt becomes less hot in the summer and remains more stable. Ironically, the asphalt chosen for its beauty will remain less beautiful. These two products have the same price, so this criterion is not important.

Best time to do this

Regarding the outside temperature, the best time to work in Quebec is the beginning of June and the end of September. From December 15 to April 15, it is risky to carry out this work, because after thawing, the soil can sag unevenly. Installation work is rarely urgent and can usually wait until June before being done.

The road surface consists of two parts: the lower part - the base and the upper part - asphalt.

Work with asphalt

Work with asphalt can be divided into three main categories: construction, repair and replacement of the top layer.

Construction

During the construction of the road, they lay the foundation, which is redone only during overhaul. If the foundation is made with high quality, then maintenance will be reduced to updating the asphalt road through patching and flooring on top of a thin layer of asphalt. If the foundation is made with errors, then an attempt to rectify the situation by replacing or increasing the asphalt layer will not work. You have to completely remove the asphalt layer, remove the upper layers of the base, and try to fix the lower ones. Often, the construction of a new road is cheaper than such repairs.

Street killers who earn us

Then you will have the best guarantee of workmanship, and the paving life can be extended. In March, more than 240 signs were dangerous in Rome by an unsightly mantle. So, the tricks: "Put the resin, then the layer will become narrower." To provide services, the state annually invests $ 5 billion. As if the country or region was suddenly canceled. 30% of victims are less than thirty years old. The infamous data describing a phenomenon of tremendous seriousness, against which various awareness-raising campaigns seem to never be affected.

Repairs

The purpose of the repair is to bring the road surface in proper condition. Depending on the damage to the pavement, patching, new flooring, or a complete replacement of the top layer of the road surface are used.

Top layer replacement

Sometimes it is necessary to replace the top layer of the road surface. For example, concrete does not tolerate temperature extremes, cracked and dusted. Or paving slabs annoy women in high heels. As a result, you have to change the top layer of the coating. In the case of asphalt flooring on the old concrete roadA thick layer is not required. Only heavy trucks will drive along the road. Thermal joints are cut in concrete and covered with asphalt. If the old coating is out paving slabs, then remove the tile, level the base with sand, and cover it with asphalt.

What is less known is that among the causes of accidents, it weighs 20% - the so-called “depletion” of infrastructure. That is, the conditions - sometimes catastrophic - of our roads. The problem with asphalt and its continuous destruction is one of those “national emergencies” that does not attract attention to other disasters, but does not save anything, and no one: large cities and small provincial centers, urban arteries and secondary roads, industrialized areas and rural areas.

An endless emergency that leads to death and injuries costs hundreds of millions of euros and makes many motorcyclists a real or potential injured population. The only city in Rome, the largest “purchasing station” in Italy, annually allocates one hundred million euros. However, the continuous river of government money, however, mostly in the cracks in the asphalt, seems to literally disappear. Where did the money go?

What determines the required thickness of asphalt?

The required thickness of asphalt depends on two factors - loads on the asphalt, and the rigidity of the base.

Asphalt in one layer

This thickness of asphalt is applicable for pedestrian paths, where cars occasionally call in, for example, parking in front of small shops. One layer of asphalt is also used for roads with a concrete base, on which only passenger vehicles move.

Who is responsible for the fact that, in addition to the decoration and image of the city, people's safety is often not guaranteed? Emergency maintenance of a business road is called “routine” when it comes to repairs. “Unusual” when it comes to excellence in the real world. In both cases, it is a business. For this reason, contracts are made up of a cake that feeds the appetites of the “asphalt lords” who are ready to win them with discounts that often exceed 40%. The numbers say clearly: they occupy jobs at a price significantly lower than the auction base and then later save on materials, labor and time, trusting the supply river, which from year to year never “breaks”.

Two-layer asphalt

This thickness of asphalt is applicable for roads along which passenger vehicles move, and the base of which is made of brick fight or crushed stone. Parking near large shops and car parks is most often done in two layers of asphalt. When laying two-layer asphalt on a concrete base, the strength of the road surface is sufficient for the movement of light trucks and buses.

Not to mention the head of control, which the contracting authorities - starting with the communes - must do strictly and in a timely manner, ready to challenge defective work. But this seems to happen rarely, and therefore birth appears. The capital of danger In a country that was able to build industry in emergency situations, it is the capital that condenses all the worst aspects of this problem. In Rome, more than in any other Italian city, this “disaster is ridiculous," because thousands of angry users define it on Internet sites, this can reveal laziness, inefficiency, and big waste.

Three-layer asphalt

A pavement with three-layer asphalt and a base of brick fight or crushed stone with a thickness of at least thirty centimeters is suitable for busy intercity routes, and the movement of any cars except heavy trucks on them.

Four-layer asphalt and more

Suitable for roads with heavy traffic of any car. With such an asphalt thickness, a concrete base has no advantages over 4-5 different fractions of crushed stone.

Sandro Salvati, president of the Ani Foundation, defines them as black dots. An elegant way to say traps. In March, in collaboration with the Romans, 243 “hole hazardous” sections were censored. “To really clear the streets of the capital, you need to spend one billion two hundred million in five years,” says Eugenio Batelli, president of Roman builders. “The one hundred million people that the municipality allocates each year,” he adds, “he can never go beyond the threshold of the required minimum.”

Then, in order to explain the weak resistance to many technical issues, he calls for movement and rain, continuous excavations of subcontracting companies, up to the ultramillion history of the city. Shadows about the quality of work? Fighting business behavior? Suspicions of inefficiency in body checks and performance tests? That seems to be the case.

Laying a thick layer of asphalt is suitable for roads with heavy traffic.

For the repair of damaged multilayer asphalt pavement that does not have deep (more than one layer of asphalt) damage.
For flooring over a concrete base, this will allow the use of the road for the movement of cars.
For footpaths.

Since you can think of building roads as one of those areas where the jungle is full of confusing rules, the rules are capillary, “mistaken” is difficult, and in fact this is not a mistake. The rule of savings Shipyard workers - asphalts - do not want to talk. They know enough to lose a place. But in the end, with some caution, some experts agree to tell. And they explain how, in many cases, work does take place. Maintaining the "rule of art" "Not really." Holes cover worse and the more they do in one day, the more you win.

Laying a thin layer of asphalt for walkways.

The thickness of the asphalt directly depends on the operating conditions of the road.

Smooth high-quality road surfaces, which provide full grip of the wheels of the vehicle with the canvas, are the key to safe and quiet traffic. Due to the active use of the road, they constantly need to be repaired and updated.

If we had not done this, it would have been “unprofitable activity”. Mario L. is 43 years old, and Roman is an asphalt worker both on the ground and in driving machines. In his “years” road construction he worked for a wide variety of companies, ”but all is almost the same, with the same methods, Serafim says, almost as if his story was not a revelation of illegal methods, but a synthesis of the obvious. “Saving on material and time is the rule,” he adds.

Usually, ”says Marco R., fifty years old,“ when we turn to the road, it’s good to go because we need to go through the first controls. Then the geometry of the company orders us “lower, lower”, and then the asphalt layer, compressed by the finisher, narrows. Therefore, you do this much earlier and save the material. A situation like the Roman has no equal. This saves on bitumen and more expensive materials. Subtle actions narrow. Perhaps moving to the fundamental steps that require regular trading, but how to do this, does not feed another profit scheme based on an emergency?

Currently, the most popular type of pavement repair is patching. This method is used more often than others, because it is much more profitable, economical and faster. However, there are also many complaints from drivers who complain about the quality of road surfaces and the rapid destruction of patches after repairs. But here the reason may lie not in the technology itself, but in those who use it. The quality of such repairs depends on compliance with the patching technology. Quite often, negligent workers do not even pay attention to the conditions and requirements that must be observed in the process of repairing roads, so an unfair and careless attitude to work more often causes damage to road surfaces.

And why are there disputes and go to the audience? The contradiction is contradictory, says Fabrizio Gera, a public works adviser. “We repaired 516% more roads than the previous administration, and we allocated 400% more.” If someone points out, however, that the holes have risen, and that in some way the work and discomfort never ends, and even the very affectionate Association of Road Victim Families said that Campidoglio is at a very late age an index against the previous junta: it's his fault, With this idea, entrust 800 km of city traffic to one operator: the Romeo Vianini-Strad Sikur Consortium.

Benefits

The patching of the road does not imply any work to restore communications, landscaping: asphalt is laid only in areas that need urgent repairs. In addition, it should be noted that such work should be carried out in strict compliance with all points technological process. This guarantees cost savings, long and maximum quality. Patching allows you to restore continuity, strength, evenness, adhesion and waterproof performance of coatings. In addition, it provides a standard site life.

Meanwhile, it was raining, there was always movement, the holes widened, people got angry. In the end, even the prefect was encouraged, the mayor and council proclaimed the state of emergency “So at a gallop with” extremely urgent. And here is a flurry of contracts, many of which are. According to official data, it’s negotiated, which means direct selection of companies without a public tender, a procedure that, in particular, in the most important works, is likely to give priority to the sign of a small entrepreneur. Your numbers are incorrect.

“No, the numbers are just that,” objected Massimiliano Valeriani, chairman of the Commission’s Transparency Committee, showing the documentation that he sent to the lawyer's audit chamber. Among other things, the law sets a limit of 500,000 euros for private negotiations and only in real situations. But how did this happen to break through the installed roofs?

Patching has been relevant for decades. There are dozens of technologies for carrying out such repairs of pavements, while the optimal method is selected based on weather conditions, the condition of the canvas, the possibilities of full use of special equipment and the specifics of the materials used. The patching of the pavement has several indisputable advantages:

The primacy of private negotiations. A private negotiation agreement is a practice that the industry supervisor considers subordinate to the exact criteria of urgency and effectiveness. In addition, to ensure market transparency, the main route has always been an open procedure, that is, an open tender. Which, in terms of money, means that it jumped from 6 million to 89 million. An “explosion”, they define it “halfway” by the experts of the Authority. Is their data “incorrect”? But this may be partial, since the body does not have a complete picture of the Feeling rewards such that the amount of entrusted work to the discretion of the city of Rome may be even greater.

there is no need to completely block the movement on the freeway / highway;
operational implementation of all necessary work (small areas are restored within a day);
lack of need to attract heavy special equipment;
patching asphalt pavement does not require huge financial costs (in comparison with the implementation

Recipe for success

Usually unscrupulous workers repair only the top layer of damaged areas. However, in fact, the technology of patching involves the restoration of the underlying layer.

From checking that, at the same time, the roads will be improved, making the capital a little less insidious for its residents and for the nine million tourists who cross it every year. From deep research and practical experience, he shows that defects and defects in granite slabs attempted to make erroneous design documentation, improper material selection, lack of proper technology in implementation, insufficient control, insufficient maintenance, etc. we will try to analyze the individual causes of the failures.

The main causes of defects and defects of hard layers of granite roofs

Causes of defects and defects resulting from material selection

First of all, this applies to all types of concrete mixers for layers, thermal insulation and leveling. Any wet process is sensitive to weather conditions and has a significant adverse effect on the quality of the plate, especially if it is considered a heat-insulating layer. The slope of the slope should be achieved by selecting the supporting structures with min. 1 °, which is a worldwide trend in waterproofing.

Before starting work, the boundaries of damage are determined, existing defects are identified, potential defects are determined, the scale of work and indicators of reliability, uniformity, strength and roughness of the coatings are calculated.

Asphalt rolling

Many domestic enterprises that carry out repair and road construction have rollers weighing more than 8 tons. Such road equipment is justified in full-scale operations, but it is not practical to apply it for patching. For compaction of several tens of meters of the road, it is better to use the “stamping” method, which is implemented by the use of manual vibration plates. Also patching asphalt is performed using small paving or vibratory rollers.

Traditional method

With this method of repair, the damaged area is first separated from the coating, this is done with the help of Then the edges of the potholes are cut off to give them rectangular outlines. Then, the defective sector is cleaned of dust and crumbs of its edge and the bottom is treated with liquid bitumen emulsion or heated bitumen, after which the asphalt mixture is poured.

The patching of the pavement, the technology of which is traditional, allows to obtain a high-quality result of work, however, it requires a significant number of operations. It is used in the repair process of various types of coatings from bitumen-mineral and asphalt concrete materials.

Repair with heating coatings and reuse of its material

Such patching of the road is based on the use of special equipment for heating coatings - an asphalt heater. This method allows you to get high-quality results, save on materials, facilitate the technology of work. But at the same time, patching of asphalt concrete pavement has significant limitations on weather conditions (air temperature and wind). This method is used in the repair process of various types of coatings from bitumen-mineral and asphalt mixtures.

Repair without cutting down or warming up the old coating

Destruction and deformation of the road surfaces are filled with cold polymer-asphalt mixture, wet organic-mineral mixture, cold asphalt, etc. The method allows for work in cold weather with wet and wet surfaces, is simple to implement, but is not able to provide high quality and durability of the coatings. This method is used in the process of repairing pavements with low traffic intensity, temporary, and also as an emergency measure on roads with high intensity.

Cold patching methods

This is a patching of the pavement, the technology of which is based on the use of cold asphalt concrete or bitumen-mineral mixtures as a repair material. These methods are mainly used in the repair process from cold asphalt concrete and on roads of low category and, if necessary, temporary or urgent sealing of potholes.

Work begins in the spring at an air temperature of at least +10 degrees. At the repair site, the coating is formed under the action of moving vehicles for 20-40 days, and its quality depends on the properties of the bitumen emulsion or liquid bitumen, mineral powder, composition and intensity of movement, weather.

Performing repairs is possible at low temperatures, while repair materials are procured in advance. The cost of repairs using this technology is less than with the hot method. The main disadvantage is the short service life of coatings on roads with the movement of buses and heavy trucks.

Hot ways

They are based on the use of hot asphalt mixes as materials: cast asphalt concrete, coarse and fine-grained, sandy, etc.

The methods are used in the repair of roads with asphalt concrete coatings. It is possible to perform work at air temperatures of at least +10 degrees with a dry coating and thawed base. When using a heater, repair at a temperature of at least +5 degrees is permissible.

Hot processes provide higher quality and longer coating life.

Preparatory operations

Before work is carried out preparatory operations:

Fences of places, road signs and lighting devices are installed during work in the dark.
Marked places (maps) of repair with a chalk or a taut cord. The repair map is outlined in straight lines perpendicular and parallel to the axis of the road, giving the contour a regular shape and capturing an intact coating.
Damaged coatings are cut, broken, or milled, and removed material is removed. It is carried out to the thickness of the destroyed coating layer, but not less than 4 centimeters along the entire length of the repair. When the pothole affects the bottom layer, it is loosened and removed to its full thickness.
Potholes are cleared of material residues, dirt and dust.
The walls and bottom are dried during the repair by hot method.
The walls and bottom are treated with bitumen or bitumen emulsion.

Basic operations

Only after preparation can the potholes be filled with repair material. The installation technique and the sequence of procedures depend on the volume and method of work, such as repair material.

With small volumes and the absence of mechanized means, styling can be done manually. Mixing is carried out in a card in 1 layer when cutting down to a depth of 50 millimeters and in 2 layers at a depth of more than 50 millimeters. In this case, a coarse-grained mixture of crushed stone can be laid in the lower layer, and fine-grained in the upper layer.

For mechanized laying, the mixture is fed from a thermos hopper.

When closing cards 10-20 square meters. m stacked by paver. In this case, laying is done in a pothole, and the mixture is evenly leveled over the entire area.

Seal asphalt mix in the lower layer of the coating is carried out by pneumatic rammers, manual vibratory rollers or electric rammers in the direction from the edges to the middle.

The mixture and mixture laid in the top layer and laid in 1 layer at a depth of up to 50 millimeters are compacted by self-propelled vibratory rollers or smooth-type static light rollers, and then heavy rollers.

For low-grained and sandy mixtures, the compaction coefficient should be not less than 0.98, for multi- and medium-grained mixtures - 0.99.

Hot mixtures condense at maximum temperatures at which deformation during rolling is impossible.

Joints that protrude above the surface of the coating are removed by grinding or milling machines.

Final operations

Final operations include measures to bring the road surface in readiness for the movement of vehicles. Workers clean up the remaining waste, garbage, load it into dump trucks. Also at this stage, road signs and fences are removed, the marking line is restored at the patching site.

Important requirements

The quality and service life of repaired coatings primarily depend on compliance with the requirements:

patching is carried out at air temperatures not less than permissible for a certain repair material on a clean and dry coating;
in the process of cutting down the old coating, weakened material is removed from all parts of the pothole where there are breaks, cracks and spalling;
it is necessary to clean and dry the repair card;
it is necessary to make the correct form of the card, steep walls, a flat bottom;
necessarily treating all surfaces of the pothole with an astringent;
repair material is laid at the optimum temperature for this type of mixture;
the layer should have a thickness slightly greater than the depth of the pothole, taking into account the margin for the compaction coefficient;
the formation of a layer of new materials on old coatings at the edge of the map is inadmissible in order to avoid jolts during collision of vehicles and rapid destruction of sections;
repair material is well leveled and compacted flush with the road surface.

Quality control

The polymerization of asphalt occurs at a temperature of more than 100 degrees and under high pressure. After compacting the mixture, the asphalt is not afraid of water. On the contrary, recoverable roadways it is advisable to water with water for quick cooling and restoration of traffic.

It should be noted that in case of incomplete compliance of the technology and violation of certain rules, asphalt concrete patches made can last at least 2 years. With strict observance of the repair technique - at least 5 years.

The carriageway must comply (after patching) GOST R 50597-93 - " Car roads and the streets. "