Pavement patch repair: technology, methods, GOST

Smooth high-quality road surfaces, which provide a full grip of the wheels of transport with a canvas, are the key to safe and quiet traffic. In connection with the active use of the road are constantly in need of repair and renovation.

Currently, the most popular type of repair of road surfaces is pit repair. This method is used more often than others, because it is much more profitable, more economical and faster. However, he also has a lot of complaints from the drivers who swear about the quality of road surfaces and the rapid destruction of patches after repairs. But here the reason may be not in the technology itself, but in those who use it. The quality of such repairs depends on compliance with the technology of patching. 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 dishonest and negligent attitude toward work often causes the destruction of road surfaces.

Benefits

Road patching does not imply any work to restore communications, landscaping: asphalt is only laid on sites that need urgent repairs. In addition, it should be noted that such work should be carried out in strict compliance with all points of the technological process. This guarantees cost savings, long life and maximum quality. Patchwork repair allows to restore continuity, durability, evenness, coupling qualities and waterproofness of coatings. In addition, it provides the normative service life of the plots.

Patchwork repair is actual for decades. There are dozens of technologies for carrying out such repair of road surfaces, while the optimal method is selected based on weather conditions, canvas conditions, the full use of special equipment and the specifics of the materials used. Pitch patching of the pavement has several undeniable advantages:

• There is no need to completely block traffic on the motorway / track;
• Operative carrying out of all necessary works (small sites are restored within day);
• No need to attract heavy special equipment;
• Patching of asphalt pavement does not require huge financial costs (in comparison with the implementation of major repairs).

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.

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

Asphalt packing

Many domestic enterprises that repair and build roads have rollers weighing 8 tons. Such road-building equipment is justified in full-scale operations, but it is not practical to use it for patching. To seal several tens of meters of the road, it is better to use the method of "treading", which is realized using manual vibrating plates. Also, pit repair of asphalt is carried out using small paving or vibrating rollers.

The traditional method

With this method of repair, the damaged area is first separated from the coating, this is done using a road mill. Then the edges of the potholes are cut off, giving them rectangular outlines. Then, the defective sector is cleaned of the dust and crumbs of its edges and the bottom is treated with a liquid bitumen emulsion or heated bitumen, and then the asphalt mixture is poured.

Pavement patch repair, the technology of which is traditional, allows you to get a high-quality result of work, but it requires a significant number of operations. It is used in the process of repairing various types of coatings from bituminous mineral and asphalt-concrete materials.

Repair with the heating of the coatings and the repeated use of its materials

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

Repair without cutting or warming up the old coating

Destruction and deformation of road surfaces are filled with cold polymer-concrete mix, wet organomineral mixture, cold asphalt concrete, etc. The method allows to carry out work in cold weather with wet and damp coating, simple in execution, but is not capable of providing high quality and durability of coatings. This method is used in the process of repairing road surfaces with low traffic intensity, temporary, and also as an emergency measure on roads with increased intensity.

Cold patching methods

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

Begin work in the spring at an air temperature of not less than +10 degrees. At the repair site, the coating is formed under the influence 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 traffic intensity, weather.

Repair is possible at low temperatures, and repair materials are prepared in advance. The cost of repair for this technology is less than with the hot method. The main disadvantage is the short service life of road coverings with the movement of buses and heavy trucks.

Hot ways

Based on the use of hot asphalt-concrete mixtures as materials: cast asphalt concrete, coarse and fine-grained, sandy, etc.

The methods are used in the repair of roads with asphalt concrete pavements. It is possible to perform work at air temperatures of not less than +10 degrees with a dry coating and thawed substrate. When using a heater, let's say repair at a temperature of not less than +5 degrees.

Hot methods provide higher quality and longer life of coatings.

Preparatory operations

Preparatory operations are carried out before the work:

1. Fences of places, road signs and lighting devices are installed during work at night.
2. The places (maps) of repair are marked with the help of chalk or stretched cord. The repair map is outlined by straight lines perpendicular and parallel to the axis of the road, giving the correct shape to the contour and capturing the undamaged coating.
3. Cut, cracked or milled damaged coatings, removed the removed material. Performed on the thickness of the destroyed layer of coatings, but not less than 4 centimeters over the entire length of the repair. When a pothole affects the bottom layer, it is loosened and removed to the full thickness.
4. Potholes are cleaned of debris, dirt and dust.
5. The walls and the bottom are dried during hot repair.
6. The walls and the bottom are treated with bitumen or bitumen emulsion.

Basic Operations

Only after preparation, potholes can be filled with repair material. The technique of laying and the sequence of procedures depend on the scope and method of work, the type of repair material.

With small volumes and lack of mechanized means, laying can be done manually. Laying the mixture is done in a map 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.

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

With the embedding of cards 10-20 square meters. M asphalt mixtures are laid asphalt paver. In this case, the laying is carried out in a pothole, and the mixture is uniformly leveled over the entire area.

Sealing of the asphalt-concrete mixture in the lower layer of the coating is carried out by pneumatic fittings, hand vibrating rollers or electric tampers in the direction from the edges to the middle.

The mixture to be laid in the upper layer and the mixture laid in 1 layer at a depth of up to 50 millimeters is compacted by self-propelled vibro-rollers or smooth-roller static lightweight rollers, and then by heavy rollers.

For low-scraped and sandy mixtures, the compaction factor should be at least 0.98, for multi- and medium-grained - 0.99.

Hot mixes are compacted at maximum temperatures, which can not be deformed when rolling.

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

Finishing operations

The final operations involve measures to bring the road surface into readiness for the movement of vehicles. Workers clean the remaining waste, garbage, dump them in dump trucks. Also at this stage road signs and fences are removed, the line of marking is restored at the site of the pit repair.

Important requirements

The quality and service life of the repaired coatings depends first of all 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 surface;
• In the process of cutting down the old coating, weakened material from all areas of the pothole, where there are cracks, cracks and dying;
• It is necessary to clean and dry the repair card;
• It is necessary to do the correct forms of the map, sheer walls, flat bottom;
• All surfaces of the pothole are treated with an astringent compound;
• Laying of repair material is carried out at the optimum temperature for this type of mixture;
• Layer should have a thickness slightly greater than the depth of the pothole, taking into account the stock by the coefficient of compaction;
• It is inadmissible to form a layer of new materials on old coverings at the edge of the map in order to avoid jolts when the vehicle hits and quickly destroys the sites;
• The repair material is well leveled and compacted level with the road surface.

Quality control

Polymerization of asphalt concrete flows at a temperature of more than 100 degrees and under high pressure. After compacting the mixture, asphalt is not afraid of water. On the contrary, it is desirable to water the restored roadbeds with water for rapid cooling and restoration of traffic.

It should be noted that with incomplete compliance of technology and violation of certain rules, asphalt concrete patches made can last at least 2 years. With strict adherence to the repair technique - not less than 5 years.

The carriageway of the road must correspond (after the patching is done) to GOST P 50597-93 - "Roads and streets".