Installation of cement-concrete bases and coatings. Road concrete - grades, composition, state

Asphalt is the main material used for road construction. After a few years, such a coating needs to be repaired, then its operational properties are restored annually. Concrete pavement is much better than asphalt pavement, but it is used to a limited extent. There are reasons for this, related to insufficient funding, low productivity, peculiarities climatic conditions, insufficient amount of cement of the required grades, relief areas. This technology is not particularly popular in Russia yet, since asphalt roads are much cheaper. However, we note that gradually the cost of these types of linen is slowly equalized. The construction of concrete roads, bridges, runways at airfields begins.

Advantages of concrete roads

Such coatings have certain advantages:

• concrete road has good strength, repair work ah no need. The coating can be used for at least four decades, and for asphalt this period is limited to a decade with annual repairs;
• automotive technology consumes less fuel. This is due to the fact that during the movement of a heavy vehicle, road concrete is not subjected to deformation, from which the vehicle needs less fuel to move a fifth;
• The coating is resistant to sudden changes in climatic conditions. It is not affected by heavy rains or sudden changes in temperature;
• there is a preservation of air purity, because cars need a smaller amount of fuel, the exhaust gases of which pollute the environment;
• natural resources are used sparingly. Limestone is used to make concrete, and oil is used to make asphalt.

Construction technology

The device of concrete roads includes certain stages:

1. The ground base is being prepared. It is rolled to achieve the desired density, if necessary, moistened or dried.
2. Water drainage is organized to extend the operational period of the canvas and give the ride safety.
3. The underlayment is being installed. It is a sandy layer, the thickness of which is up to two to four tens of centimeters.
4. The formwork structure is being assembled. Its elements are made of lumber, while taking into account the height of the fill.

If water seeps into the ground, the pavement is gradually destroyed.

The construction technology is complex, and each stage will be considered in detail.

Concrete road structure

The canvas includes certain layers:

• underlying - for its device, gravel is used, which drains ground water, and sand, with whose help the arising loads are compensated;
• reinforcing - represented by low-grade concrete that binds the bulk layer;
• the roadbed is a concrete surface.

The construction of a concrete road for heavy vehicles is made of stressed and non-stressed reinforced concrete, the reinforcing frame base in which does not allow the stone to crack from the weight of trucks.

In private types of construction work or when arranging a concrete pavement of roads on soils oversaturated with moisture, a waterproofing material is laid out on a sand cushion, which prevents the roadway from becoming very wet, followed by corrosion of stones and reinforcement. As a waterproofing material, ordinary roofing material is used.

Execution of works

Let's take a closer look at what constitutes a particular construction stage of concreting roads.

Training

Earthworks are difficult, and they are quite expensive. Their beginning is preceded by the preparation of a detailed design solution, the conclusions of which are based on geological studies of the area. If there is such an opportunity, then the concreting of roads is carried out horizontally, removing small hills or laying compacted rock in the recesses.

If a major highway is being built, then the layer of fertile land is removed in full, and for the construction of a concrete road in the yard, it will be enough to remove from fifteen to twenty centimeters of soil.

The prepared base is compacted by rollers and vibration mechanisms, which are characterized by a large weight.

This stage is considered a crucial moment, since the stiffness index and the integrity of the road surface depend on the strength of the base, even when dynamic loads are quite intense.

During earthworks, a drainage system is thought out so that it is possible to remove ground and rain moisture. For this purpose, the base is brought out in a plane, the inclined angle of which is from two to four degrees. Concrete gutters are installed on the sides of the road or slopes of a natural type are arranged, along the slopes of which water will enter the receiving wells or go into the ground.

Litter layer

A sand cushion is arranged, the thickness of which is twenty to forty centimeters. This element can be omitted, but it perfectly protects against moisture coming from the ground, improves the drainage process. The bedding layer is necessary to prevent erosion and swelling during frost, which leads to the formation of cavities and cracks in the cast-in-place concrete.

Most problems appear on clay, peat and other areas of the terrain that can hold water. In most cases, such layers are partially removed, the bottom is covered with large stones and gravel. The rolled layer reaches a height of thirty centimeters. From such training will depend on the costs and time required for construction.

The minimum thickness of the base depends on the type of soil and climatic conditions. Determine it according to a special table. If the layer is laid out from various materials, then a geotextile is spread between them.

Align the layers in accordance with the designed slopes. Stone backfills are strengthened with binders - cement, granulated slag from metallurgical production, to which quicklime is added, ash from thermal power plants, ground slag.

formwork

For the manufacture of this structure, boards are used, the height of which corresponds to the level of pouring concrete for the road. As a rule, it is equal to ten to fifteen centimeters. When determining its dimensions, it must be taken into account that ribs are arranged along the edges of the concrete to improve strength. The thickness of the boards should not be less than 5 cm. Each structural element should be covered with a special compound that will facilitate detachment from the hardened concrete.

Requirements are imposed on wooden formwork panels in terms of strength from expansion by their fresh concrete mass and the forces that arise as a result of tamping.

If heavy machinery is used for the construction of roads made of concrete, with which the concrete is compacted, then a formwork made of steel material should be installed. It will last much longer. At the heart of each element is a sole that improves stability.

Formwork sections are set in one line, firmly fixed. This is especially important if the vibrating of the concrete mass is carried out by heavy machinery. In places where the level of the base is reduced, lean concrete is poured under the formwork to improve stability.

Reinforcement

If the technological process of constructing a concrete road involves this type of work, then the reinforcement should be a metal mesh, the cell area of ​​which reaches 150 mm. sq. This choice of material will make it possible to avoid expansion and the appearance of cracks in the concrete thickness.

Laying of the reinforcing mesh is carried out in the process of pouring the concrete mixture at a height of three to four centimeters from the lower level. Before this, the poured concrete is leveled, the frame mesh is covered, and, if necessary, fixed. Now you can continue to work.

fill

The litter layer is covered with a material that is resistant to getting wet, waterproofing, or simply moistened. Road concrete, corresponding to GOST, is laid out in thickness in one go. When reinforcement is applied, the process is carried out in stages.

Concrete for the road, the brand of which meets all the requirements, is applied quickly, since it does not have a long pot life. It is not recommended to add water to the mass, because the mechanical properties of the coating will deteriorate. Since construction volumes are large, factory-prepared road cement is delivered to the place of work. The mixture is unloaded in one cubic meter and leveled to give the entire layer the same density.

The best option for laying a concrete canvas is two or three layers.

The concrete mixture is compacted by special mechanisms, represented by wooden or metal beams, which are acted upon by pneumatic hammers mounted on them. Such a device descends into the mixture, begins to move in it. Having processed one section, the beam is moved further.

If reinforcement is used, then the vibration device should be located five to seven centimeters above the upper edge of the frame.

In a special machine, in addition to the vibration device, there is also a leveling device located in front.

The concrete composition must be flexible and sufficiently mobile, but not too liquid, so that it cannot float, flowing through the formwork panels. All this will negatively affect the strength of the coating.

Seam cutting

A prerequisite is the device of expansion joints. This type of work is possible when concrete reaches a certain level of strength, which is 50 - 60 percent. In this form, the canvas is able to withstand the weight of not only the worker, but also a special tool for cutting seams.

In this way, the thermal expansion to which concrete is subjected to varying degrees is compensated. Road segments do not form cracks during seasonal changes.

Sawing is performed by jointing - a special tool. The distances between the seams are determined by design calculations. As a rule, for this, the thickness of the monolithic coating is multiplied by thirty.

To prevent moisture from getting into such seams, they are filled with mastic.

Materials for constructing a concrete web

M400 - universal concrete composition. Its strength allows it to withstand loads from various wheeled vehicles. The basis is Portland cement, which is resistant to moisture. Plasticizers are also added to the solution to improve hydrophobicity and strength.

The concrete mixture consists of:

• cement - 1 part;
• gravel - 5 parts;
• sand - 2 parts.

The composition of concrete and its characteristics are specified in the construction project.

Slab covering device

Concrete slabs for the road are made as follows:

1. Forms are being prepared right size, or shuttering boards are exposed.
2. If necessary, a reinforcing cage is prepared to improve the strength of the plates.
3. Pouring is carried out with a ready-made concrete mixture, it is advisable to immediately tamper to remove air bubbles.
4. After some time, when the concrete hardens, you can remove the formwork and give the slabs time to gain the desired strength.

With the help of such material, you can make a concrete road with your own hands. Under all conditions, it will serve you well for a long time.

Conclusion

The concrete pavement of the road is durable, but needs some maintenance. The resulting cracks must be immediately repaired so that they do not increase in size. To do this, use special putty compositions or concrete mortar. If a fracture has formed, the entire section of the concrete sheet should be removed.

Currently, two technologies are used in road construction in Russia:

• With the use of traditional asphalt concrete pavements, in which the binder is bitumen;
• Using cement-concrete coatings, in which the so-called road concrete is used.

Traditional asphalt paving technology is not very suitable for the Russian climate. Roads with such a coating are constantly being repaired, but their quality does not improve from this. The experience of European countries that started building cement-concrete roads showed the promise of such autobahns. And it's not even about the obsolescence of asphalt concrete technology. It has been discredited by the wrong methods of its application.

Asphalt-concrete roads, as an engineering solution, in Europe and the USA are a concrete base, on which there is asphalt applied in a thin layer. In Russia, asphalt pavement, in which the binder is not cement, but bitumen of the lowest quality, is laid in best case on a monolithic base of low-quality "lean" concrete, and most often - on gravel or sand bedding.

At present, only a small percentage of Russian highways has a concrete surface, mainly federal highways. Most of the Russian roads do not meet modern transport standards.

Advantages of concrete road surfaces

The technical and economic advantages of cement-concrete pavements over asphalt concrete pavements are undeniable:

• Sufficiently high strength allows the passage of heavy vehicles;
• High surface roughness allows high-speed traffic in rainy weather;
• Small wear of the roadway;
• Concrete durability for road construction to the aggressive environment;
• No dust;
• Small amount of current repair work;
• Durability in comparison with asphalt concrete roads, the service life reaches 50 years;
• Possibility of mechanization at all stages of construction.

According to experts, the continuation of the asphalt-bitumen strategy in the construction of Russian roads will not allow getting out of the vicious circle of "laying-repair", although huge funds are allocated annually for road maintenance.

The main differences between road concrete

The extreme nature of the operation of concrete pavements of autobahns is distinguished by the following negative factors:

• Cyclically changing freezes and thaws;
• Moisturizing and drying.

Due to such a set of negative impacts, the concrete roadbed is constructed from a special concrete material that differs from conventional types of concrete used in construction and landscaping. Concrete paths in a private house are poured with a completely different composition than a federal highway or an airfield runway.

Concrete road surfaces have the following positive characteristics:

• Increased wear resistance;
• High rates of mechanical compressive strength and tensile strength in bending;
• Low abrasion;
• Resistance to temperature changes;
• Frost resistance;
• Moisture resistance.

Comparative formulation of road concrete

Modern highways are constructed from heavy concrete, which incorporate heavy fillers with a fraction size exceeding 5 mm. The density of such concretes ranges from 1800-2500 kg/cu. m. Filler - gravel and crushed stone, which is based on basalt, granite, limestone.

It is important! For comparison, lightweight concretes, which include foam concrete, expanded clay concrete, wood concrete and other similar materials with a loose filling component, have a density in the range of 500-1800 kg / cu. meter.

For the construction of highways and city roads, for transport routes at industrial facilities, in the construction of airfields, in the manufacture of curbs, heavy concretes with a high content of crushed stone filler and a reduced weight fraction of binder-cement, called "lean concretes", are used. Such a dosage reduces the cost of producing a concrete mixture for an extended range of building structures, since a mixture of such a composition is cheaper than high-quality concrete compositions.

The composition of lean concrete includes:

• 1 weight part of binder-cement;
• 3 parts by weight of filler-sand;
• 5 or 6 weight parts of fillers - gravel or crushed stone.

The dosage of water is determined based on the requirements for road concrete of a given grade and the grade of cement used. Ordinary lean concrete is characterized by rigidity (F), which differs from ready-mixed concrete prepared according to the recipe regulated by GOSTs. In the range of lean concretes produced, there are compositions with stiffness Zh1-Zh3 and super-rigid compositions SZh1-SZh3, however, the following grades are most popular:

• M100 V7.5 Zh4 and
• M200 V15 Zh4.

Road concrete is a slightly different composition compared to lean concrete.

The difference lies in the content of special plasticizers, which give road concrete a higher mobility compared to lean concrete, which is important when laying road concrete in the process of road construction. The indicator of the mobility of the mixture P1 is added to the marking of road concrete. For example, the designation of one of the grades of used concrete road mixes M150 P1 F100 W2 is class B12.5. The corresponding letters in the designation mean the following indicators:

• "P" - the mobility of the mixture;
• "F" - frost resistance of the mixture;
• "W" - water resistance.

Rationing the water-cement ratio W / C allows you to more clearly subdivide the strength characteristics for road concrete intended for a particular type of coating. In different climatic zones, for concretes of single-layer pavements or the upper layers of two-layer road pavements, W / C is taken within the range of 0.5-0.55. In the same two-layer coatings, the bottom layer is produced with a W / C index exceeding 0.6.

But for modernized coatings, the base is made from mixtures with non-standard W / C.

It is important! Road concrete should be delivered only by dump trucks, as the mixture is stratified in automixers, the characteristics and quality of road concrete are lost.

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Road repair equipment

Construction of cement concrete pavements

The technology of cement concrete pavement installation consists of the following operations: - preparatory work; - delivery of the prepared mixture to the installation site; – mixture distribution; – formation of a constructive layer; – compaction of the cement-concrete mixture; – surface finishing of cement concrete pavement; – maintenance of freshly laid concrete; - arrangement of seams; - sealing seams.

To preparatory work when installing cement-concrete pavements, these include: 1) installation of copy strings, which ensure the evenness of the structural layers of the pavement and their planned and high-altitude location during the operation of concrete-laying machines with sliding formwork; 2) installation of rail-forms for the operation of machine sets on rail-forms;

3) procurement and installation of reinforcement and structures of expansion joints.

The tension of the copy string is made from two sides for the operation of the concrete paver with a sliding formwork. Copier strings are fixed in brackets on racks. Racks are set using a theodolite and a level at a distance of 4-6 m from each other on curved sections and after 15 m on straight lines. Brackets are mounted on racks at a height of 0.5-1.0 m from the surface of the underlying layer. The deviation of the copy string from the vertical marks should not exceed ±3 mm.

Installation of rail forms is a labor-intensive operation performed with the help of surveying tools and a truck crane. Rail-forms are intended for the movement of a set of machines along them and at the same time they are a formwork for concrete.

Rail-forms should be installed on a planned base with a width of at least 0.5 m on each side of the concreting (made of crushed stone, gravel or soil reinforced with binders) or on a base widened for this purpose under the coating. It is not allowed to settle the base from the impact of concrete-laying machines during laying. To do this, the installed rail-forms should be run in with the heaviest machine of the set. Deviation of marks of rail forms after running-in should not exceed +5 mm. Directly before laying the concrete mixture, the rail-forms must be lubricated with inside used oil.

Rail-forms should be separated from concrete using devices that ensure the integrity of the side faces and edges of the laid layer, not earlier than 24 hours after laying.

When installing cement concrete pavements in areas of high embankments above pipes, on the approaches to overpasses, bridges, the coating layer is reinforced.

Metal meshes are installed in the design position using concrete crackers or reinforcing embedded parts.

Delivery of the prepared mixture to the place of laying can be carried out by various means of transport, taking into account the amount of work and the distance of transportation. The range of transportation of the mixture should be calculated taking into account the temperature and humidity of the surrounding air, on which the setting speed of the cement concrete mixture depends. According to SNiP 3.06.03.-85, the mixture must be delivered to the place of concrete work no later than 30 minutes at an air temperature of 20-30 ° C, 60 minutes - at a temperature of 10-20 ° C.

To control the fulfillment of this condition, it is necessary to keep a strict record of the order of the movement of vehicles, if the Central Library serves only this object, or each vehicle must be equipped with supporting documents(passport of the mixture), which indicate the brand of cement concrete mixture, the mobility of the mixture, the time of its preparation and the place of laying. In places of unloading, it is necessary to equip washing points for cleaning car bodies from the remains of the cement-concrete mixture. Motor vehicles must have a waterproof body with a smooth, even surface.

Long-term transportation adversely affects the quality of mobile mixtures. It is not recommended to transport mobile mixtures in vehicles without prompting on the way over a distance of more than 10 km on a good road and 3 km on a bad one. Concrete mixer trucks are used as concrete trucks with impulse. Concrete mixer trucks are also used for preparing concrete mix en route to the place of laying.

The range of transportation of dry mixes is limited for economic reasons by the distance over which ready-made concrete mixes can be transported with impulsion (slow rotation of the drum 3-4 rpm) without compromising the quality of the mix.

When installing cement concrete pavements, the most time-consuming operations are the distribution, formation, compaction and surface finishing of the cement concrete pavement. For the production of these operations, sets of concrete paving machines are currently widely used.

The development of concrete paving machine sets is carried out in two directions: the creation of high-performance concrete paving machines with sliding formwork and concrete paving machines using rail forms.

Slipform pavers are tracked machines designed for continuous laying of cement concrete pavements in the construction of roads, airfields, canals. Traditionally, for these purposes, sets of concrete-laying machines DS-100 and DS-110 were used, at present a number of companies are entering our market offering their services in updating the fleet of construction machines.

Wirtgen slipform pavers are highly economical. Their modular design allows the machine to be quickly reconfigured depending on the job ahead.

Sliding molds can be hung between the running gears or sideways using the "offset" (offset) method. Thus, it is possible to use the same machine for covering a 7.5 m wide pavement and for forming an edge drainage tray, a reinforcing strip, and a guide wall.

The unloading of the cement concrete mixture is carried out directly on the base in front of the concrete paver or concrete mix distributor, if the base is strong enough for vehicular traffic. Otherwise, the mixture is unloaded into a receiving hopper located on the side. From the receiving hopper, the mixture is fed by a conveyor to the distributor auger. The distributor screw consists of two parts, each of which can rotate in two directions. This ensures uniform distribution of the cement concrete mixture across the width. Wirtgen's SP 1600 slipform pavers make it possible to form two-layer cement concrete pavements in one pass. One concrete paver is used for the simultaneous laying of the concrete base layer and concrete cover.

The cement-concrete mixture for the foundation device is fed directly to the base in front of the concrete paver, and the mixture for the top layer of the cement-concrete coating is fed into the receiving hopper located on the side or in front of the concrete paver. From the receiving hopper, the cement-concrete mixture is fed by a conveyor to the working body, which distributes and compacts the top layer of the cement-concrete coating. Sliding formwork can form the side surface of the layer to be flat or curved for better adhesion between adjacent strips.

The formation of the mixture along the width of the coating is carried out by the concrete mix distributor or by the concrete paver itself. When using a distributor, the concrete mixture is distributed to a given width with a certain thickness margin for compaction. The margin for compaction is specified by trial concreting.

The compaction of the cement concrete mixture and the final formation is carried out by a concrete paver. To compact the mixture, the concrete paver is equipped with internal vibrators, vibrating bars and a screed.

When vibrating, the grains of crushed stone and sand are denser, and the air in the mixture is forced out. When compacting, different vibration frequencies are used. Low frequencies contribute to the compaction of larger particles, and high - small ones. In this case, dense concretes are obtained with a short duration of vibration. The oscillation frequency is in the range of 460-1000 Hz.

The quality of vibrocompaction also depends on the duration of vibration. Its optimal duration depends on the workability of the mixture and is in the range of 60-90 seconds.

When vibrocompacting cement concrete surfaces, the upper layers are often enriched with excess water squeezed out from the thickness of cement concrete. This can lead to an increase in the porosity of the cement stone and a decrease in the strength of the top layer.

For the final finishing of the coating, the set of machines for the device of cement concrete pavements includes a concrete finishing machine - a pipe finisher. The working body of this machine is an asbestos-cement pipe suspended from the frame of the machine. By moving the pipe over freshly laid concrete, the surface is smoothed out. To prevent the destruction of the edges of the freshly laid coating during the first passes, the asbestos-cement pipe is installed at an angle to the axis so that the edges of the pipe do not reach the edges of the coating by 15-20 cm.

To remove the water squeezed out during vibration, the concrete finishing machine provides for hanging a moisture-absorbing cloth, such as burlap. At the end of the working shift, the burlap is thoroughly washed, cleared of cement laitance. The finishing machine also has attachments for applying grooves to create roughness. The average depth of the roughness grooves, determined by the "sand spot" method, depending on the required value of the coefficient of adhesion of the wheel with the coating, should be in the range of 0.5-1.5 mm. The texture of the treated coating must be uniform.

The next technological operation is the care of hardening concrete. This operation consists of a set of measures that provide favorable conditions for the hardening of the mixture laid in the coating. Measures include preventing the evaporation of moisture from concrete, which is necessary for the process of concrete structure formation, as well as protecting it from mechanical damage in the initial period of curing.

The duration of care is up to the set of design strength, but not less than 28 days.

To prevent the drying of concrete pavements, the surface is treated with film-forming materials, which can be used as powder (PM-86), lacquer "Etinol", bituminous emulsions. Bituminous emulsions are used less often, since the creation of a dark surface contributes to the heating of the coating, which is harmful to early stages strength set. To reduce surface heating after film formation, the coating treated with bitumen emulsion should be covered with a layer of sand 5 cm thick or suspensions of aluminum powder or lime mortar are applied to brighten the surface.

Currently, film-forming materials of the PM type are used to care for concrete. They are applied to the concrete surface in an amount of at least 400 g/m2 at an air temperature of up to 25 °C and 600 g/m2 at a temperature of 25 °C and above, as a rule, in two layers with an interval of 20-30 minutes.

Film-forming materials must be applied by spraying with a multi-nozzle distributor evenly over the entire exposed surface of the slab (including the side edges) after finishing the coating.

Film-forming materials of the PM type should be applied after the moisture has evaporated from the concrete surface (the surface becomes dull), and an aqueous bitumen emulsion should be applied immediately after finishing the surface of the concrete coating. In the event of a delay in the application of film-forming materials, fresh concrete must first be protected by applying a moisture depressant to prevent drying of the surface. As a depressant for moisture evaporation, a depressant of the DSSh brand should be used at a flow rate of 5-10 g/m2. Wet burlap is allowed. In the event of precipitation, rolled vapor-tight materials should be used.

To reduce the stresses arising from seasonal and daily changes in air temperature, expansion joints of compression, expansion and warpage are installed in cement concrete pavements.

At an air temperature exceeding that at which the coating was arranged, thermal elongation of the cement-concrete coating slabs occurs; expansion joints are arranged to ensure such an elongation.

The length of the concrete pavement increases in proportion to the distance between the expansion joints, the coefficient of thermal expansion of concrete and depends on the temperature difference of the pavement in this moment and at the time of installation. In expansion joints, the coating is cut across the entire thickness of the slab and over the entire width. This is done with a wooden lining.

At air temperatures below that at which the cement concrete mixture was laid, the cement concrete pavement slab tends to shorten. Compression joints allow for shortening of concrete pavement slabs. When the length of the slab is reduced, the frictional forces between the coating and the base cause tensile stresses in the cement concrete coating. Compression seams reduce these stresses and the associated potential for cracking. In compression joints, the coating is cut across the entire width by 1/3 - 1/4 of the thickness, below this slot, and a crack occurs later.

Seams in the longitudinal direction are arranged with a coating wider than 4.5 m. This seam is called a longitudinal seam, or warp seam, as it allows for the possibility of thermal warping in the transverse direction and reduces the likelihood of longitudinal cracks.

Grooves of expansion joints should be cut mainly in hardened concrete with diamond discs when the concrete reaches a compressive strength of 8-10 MPa. It is allowed to arrange seams and grooves of compression seams in a combined way: laying an elastic gasket in freshly laid concrete and cutting a groove along it in hardened concrete.

The expansion joint element (Fig. 4.15) should be securely fastened with pins before concreting in accordance with the project. Before installation in the design position, the board lining should be soaked in water for 24 hours or lubricated on all sides with liquefied bitumen. The pins of the transverse compression joints should be installed in the design position before concreting the pavement using supporting devices or embedded into freshly laid concrete by vibration immersion.

Rice. 4.15. Typical design of a transverse expansion joint: 1 - reinforcement; 2 - reinforcing body; 3 - wooden gasket; 4 - bituminous coating; 5 - plastic cap; 6 - rubber compensator

The start time for grooving the joints should be determined based on concrete strength data and verified by trial cutting. During test cutting, chipping of the edges of the seams should not exceed 2-3 mm. With daily air temperature fluctuations of less than 12 °C, the grooves of the transverse compression joints in the coating should be cut on the same day. If it is impossible to cut all the seams in a row due to unacceptable chipping of the edges of the seam, control compression seams should be arranged through three or four slabs using a two-stage method: cutting a narrow groove of the seam with one diamond disk when the concrete compressive strength is reached about 5-7 MPa and subsequent cutting the upper part of the joint to the design dimensions when the concrete strength reaches more than 10 MPa. If it is impossible to install control seams using a two-stage method and cracks appear in the coating, control seams should be arranged in a combined way.

With a daily air temperature difference of more than 12 ° C, the grooves of the transverse compression joints in the coating laid before 13-14 hours should be cut on the same day. In the coating laid in the afternoon, to ensure crack resistance, control transverse seams should be arranged through two or three slabs in a combined way, and subsequent cutting of intermediate seams should be made in hardened concrete.

When arranging control transverse seams in a combined way, an elastic tape (gasket) with a thickness of 0.2-3.0 mm should be laid in the concrete, and then a seam groove in the hardened concrete should be cut along the tape. As an elastic gasket, polyethylene tape and other similar materials can be used after finishing the surface of the concrete pavement. Installation of the tape according to SNiP 3.06.03.-85 is not allowed if the concrete mixture has lost its mobility and the tape is not monolithic. The tape should be laid to a depth of at least 1/4 of the coating thickness and protrude 0.5-1.0 cm above the surface.

At the end of the work shift and in the event of a forced break in work, work transverse seams should be arranged, as a rule, by the type of warping seams using attached formwork. The laying of the coating from the working joint should be continued after the formwork has been removed and the end of the slab has been coated with thinned bitumen or film-forming material. If an expansion joint is required at a given place, it is arranged at a distance of one plate before or after the working joint.

Joint sealing work is carried out in dry weather at an air temperature of at least +5 °C. Filling of joints cut in freshly laid concrete is carried out after 7 days, and in hardened concrete - immediately after they have been washed and dried.

Works on filling expansion joints with mastics prepared on the basis of bitumen should be carried out in the following sequence: and lay a cotton cord on the bottom of the groove of the joint; and lubricate the walls of the groove of the seam with liquefied bitumen; and fill the groove of the seam with mastic 2-3 mm above the level of the coating;

□ Cut off excess mastic that protrudes above the seam groove with a sharp scraper.

Sealing materials prepared on the basis of bitumen must be heated to a temperature of 150-180 °C before use.

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Concrete, cement-sand and mosaic (terrazzo) coatings

Cement-sand floors are used only in utility and service rooms, usually located in the basement floors, as well as on alcons, in boiler rooms, coal rooms, etc. with a rail and a novation plane, no more than 10 mm are allowed. With large gaps, irregularities are filled with a hard cement-sand mortar. When leveling the concrete base, the surface is pre-incised and thoroughly washed with water before laying the cement-sand mortar. Aligned places are compacted with surface vibrators and leveled without grout for better adhesion to the monolithic coating. When controlling the quality of mosaic floors, it is necessary first of all to check the quality of the raw materials: - the size of crushed stone and gravel is allowed no more than 15 mm or 0.6 of the coating thickness; - mosaic chips (fine crushed stone) and sand for mosaic composition should be made from polished hard rocks - marble, granite, basalt, etc. with a compressive strength of at least 600 kg / cm2; for monolithic floors it is allowed to use pure quartz sand; - for white or light-colored mosaic coatings, white (GOST 965-78) or bleached ordinary cement should be used; for bleaching, stone powder with a particle size of not more than 0.15 mm is added to ordinary cement from white or light stone materials with a compressive strength of at least 200 kg / cm2 in an amount of 20-40% of the mass of cement. In the manufacture of colored coatings, it is necessary to strictly control that for coloring only silk-resistant, light-resistant mineral pigments are added to white or bleached cement in an amount of not more than 15% of the volume of cement. The use of gypsum and lime for whitening cement is prohibited. Mosaic mixture (concrete) and cement-sand mortar are laid into the coating in strips (sections) not more than 2.5 m wide, bounded by slats that simultaneously serve as beacons. The height of the installed rails should be 30 mm, which after grinding provides a floor thickness of 20 and 30 mm in the high sections of the base. The mixture is placed 3-5 mm above the rails based on its compaction during vibration. The mixture is compacted with platform vibrators or vibrating screeds. Excessive vibration can cause most of the large grains to settle, resulting in a uniform surface after grinding and reducing the wear resistance of the concrete floor. Therefore, vibration and tamping must be stopped immediately after the appearance of laitance on the surface. After compaction, the surface of the coating is smoothed with steel trowels. Smoothing should be completed before the concrete or mortar begins to set. Sprinkling of cement on mosaic and concrete pavements during their smoothing is prohibited; ironing of cement-sand coatings is allowed only if indicated in the project. After compaction and smoothing, the beacon rails are carefully removed, and the grooves are filled with a mixture and smoothed with steel trowels to the same level with the compacted surface. As veins, depending on the pattern of the floor, strips of aluminum, brass, plastic are used, which can also serve as beacons at the same time. The upper layer of the mosaic mass is laid 1-2 hours after the laying of the lower layer and alignment of the veins. The processing of the mosaic flooring is carried out similarly to the processing of single-layer simple mosaic floors. Before final grinding with fine-grained stones, the surface of the coatings must be washed with water, and small scratches and carefully wipe the pores with cement with the addition of stone flour (and for color coatings with the addition of pigment). When resuming the laying of monolithic floors after a break in work, the vertical edge of the hardened concrete or mortar is cleaned of the cement film, dust and dirt with steel brushes, moistened and primed with cement milk with wash brushes.
Rice. 39. Installation of veins in mosaic floors: a - varieties of veins; b - installation of veins; 1- glass vein; 2 i. 3- metal veins with various mounts; 4 - plastic vein; 5 - mosaic mixture of terrazzo); 6 - cement-sand mortar. Compaction and smoothing of concrete and mortar in places of working seams is carried out until the seam becomes invisible. To increase the durability of cement-sand coatings, they are ironed. Ironing must be completed before the cement>sand mortar begins to set. Ironing of the hardened coating is prohibited. To improve the water resistance of concrete, mosaic and cement-sand coatings, fluates, liquid glass and calcium chloride are used. Surface impregnation of fluatam coatings (with aqueous solutions of hydrosilicic acid or its zinc, aluminum and magnesium salts, prepared no earlier than 5 days before application) is carried out no earlier than 10 days after laying concrete or cement-sand coatings. Before impregnation, the coating is dried and thoroughly cleaned. It is necessary to control that the impregnation with fluates was carried out three times with intervals of at least 24 hours, and the concentration of the solution was increased with each subsequent treatment (3-7-G2% by volume). Impregnation of the coating with sealing compositions must first be carried out with liquid glass (GOST 13078-67) with a specific gravity of 1.07, and after a day - aqueous solution calcium chloride with a specific gravity of 1.12. On the impregnation of the surface of the coating is an act. After the final grinding of mosaic and concrete floors before putting them into operation, walking on them and transporting materials, mechanisms and tools is not allowed. Finished mosaic and concrete floors are recommended to be sprinkled with wet sawdust, which is removed before putting the floors into operation. When accepting mosaic and concrete polished floors, check the grain. polishing quality, preservation of the veins in the presence of a pattern, the absence of noticeable scratches and potholes. Cement-sand floors must have a perfectly smooth surface. The horizontalness of the floor is determined by applying a control rail in different directions, visible gaps for all types of monolithic floors should not be more than 4 mm.

8.2.2 In livestock buildings, concrete floor coverings are recommended for use in machines, boxes, etc. when animals are kept on bedding or when using mats or slats, as well as in driveways and aisles.

8.2.3 Concrete pavements can be designed in the form of an exploitable underlying layer, on a concrete base and on a reinforced concrete floor (Fig. 3 and 4).

8.2.4 The coating thickness should be assigned depending on the intensity of mechanical impacts (Section I, Table 2). When performing a coating that simultaneously performs the function of an underlying layer, the thickness should be increased by at least 100 mm.

8.2.5 Coatings with a thickness of 50 to 120 mm are recommended to be reinforced with one layer of a metal mesh made of wire with a diameter of 5 mm with cells of 100x100 or 150x150 mm, with a thickness of 120-180 mm - with two layers of a metal mesh, and with a thickness of more than 180 mm, a frame determined by calculation. The lower layer of the metal mesh is laid on spacers with a thickness of at least 20 mm, the upper one - with 6x6 m cards, and in special cases with 3x3 m cards on supports welded to the bottom layer of the mesh.

Rice. 3 Structural schemes of floors with concrete coating along the underlying layer ( a) and over the overlap ( b)

1 - concrete pavement; 2 3 - waterproofing; 4 - base soil; 5 - heat and sound insulation; 6 - overlap; 7 - pipeline.

Rice. 4 Structural schemes of floors with steel-fiber concrete coating along the underlying layer ( a) and over the overlap ( b)

1 - steel fiber concrete coating; 2 - concrete underlay; 3 - waterproofing;

4 - base soil; 5 - heat and sound insulation; 6 - pipeline; 7 - overlap; 8 - concrete screed.

8.2.6 Steel fibers 50-80 mm long and 0.3-1 mm in diameter can also be used to reinforce concrete pavements. At the same time, it is recommended to use fine-grained concrete of class B25 and B35 with maximum size coarse aggregate 20 mm (Table 8.2.1). Steel fiber reinforced concrete coatings are recommended to be made with a thickness of 40-100 mm.

Table 8.2.1

8.2.7 In floor coverings with a thickness of more than 50 mm, it is recommended to provide expansion joints in the longitudinal and transverse directions with a step of 3 to 6 m. boundaries of the top layer of reinforcement. The depth of the expansion joint should be at least 40 mm and at least 1/3 of the coating thickness, the width should be 3-5 mm.

8.2.8 When performing floor coverings on the base soil, in order to prevent floor deformation if the building is subject to settlement, cut-off of the floor covering from columns and walls through gaskets made of rolled waterproofing materials should be provided.

8.2.9 Portland cement (GOST 10178-85) of at least grade 400 should be used for concrete preparation. At the same time, sulfate-resistant expanding cement is recommended for waterproof and frost-resistant concrete.

8.2.10 For light-colored coatings, white (GOST 965-78) should be used, and for colored coatings - colored cement (GOST 15825-80) grade not lower than 400.

8.2.11 Crushed stone from natural stone (GOST 8267-82), gravel (GOST 8268-82) and crushed stone from gravel (GOST 10260-82) for concrete classes B30, B22.5 and B15 must have a strength of 100, 80 and 60, respectively MPa. The size of crushed stone or gravel should not exceed 15 mm and 0.6 of the total thickness of the coating.

8.2.12 Quartz or crushed sand (GOST 8736-85) from natural stone of crystalline rocks (granite, syenite, basalt and the like), coarse or medium-grained, used for concrete coatings, must contain no more than 3% clay or silt particles .

8.2.13 Consumption of coarse aggregate for concrete coatings (crushed stone, gravel, marble chips) must be at least 0.8 m 3 per 1 m 3 of concrete, and sand 10-30% of the volume of voids in coarse aggregate.

8.2.14 For non-sparking concrete coatings, crushed stone and sand from limestone, marble and other clean stone materials that do not form sparks when struck by steel or stone objects should be used.

8.2.15 For alkali-resistant concrete coatings, it is recommended to use crushed stone, gravel and sand from dense sedimentary (serpentinites, porphyrites, limestones, dolomites) or igneous (diabases, granites) rocks or basic blast-furnace slags. It is allowed to use pure quartz sand. Materials for such coatings must withstand at least 15 cycles of alternate saturation with a solution of sodium sulfate and drying without signs of destruction.

8.2.17 For concrete pavements produced by vibration treatment, it is recommended to use the concrete compositions given in Table 8.2.2

Table 8.2.2

8.2.18 Concrete mixes, which do not contain plasticizers, for coatings made by vibration treatment, should be characterized by a cone draft of 2-4 cm. 8% by weight of cement.

8.2.19 Works on laying concrete and steel-fiber-concrete mixtures should be carried out at an air temperature at floor level of at least +5 °C. This temperature should be maintained until the concrete acquires 50% design strength. When placing concrete in winter conditions at negative temperatures, sodium nitrate, potash, etc. should be added to the concrete mixture. In this case, it is possible to highlight white spots on the surface of the concrete coating.

8.2.20 Before laying concrete mixtures, the underlying layer must be cleaned of dirt and dust, and grease stains removed by washing with a 5% solution of soda ash, followed by washing with water.

8.2.21 Slots between prefabricated floor slabs, their junctions with walls, as well as mounting holes should be sealed with a cement-sand mortar with a strength of at least 15 MPa, flush with the surface of the slabs.

8.2.22 It is recommended to glue the lower parts of walls and columns to a height equal to the thickness of the coating with waterproofing roll material or, in the case of expansion joints in these places, with polyethylene foam sheet.

8.2.23 When laying coatings up to 50 mm thick, to improve interlayer adhesion, it is recommended to prime the surface of the underlying concrete layer with a composition based on PVA emulsion or latex.

8.2.24 When installing floor coverings on old oiled concrete bases, it is recommended to provide a separating layer of polyethylene film, kraft paper, etc., and make the floor covering at least 100 mm thick from concrete of a class not lower than B30.

8.2.25 The concrete mix should be laid on the base in strips limited by beacon rails (rolled metal, non-removable aluminum or concrete rail forms) with a height corresponding to the thickness of the coating. In this case, the width of the strips is selected taking into account the technical characteristics of the equipment used, the distance between the columns in the building, as well as the planned location of expansion joints. Mounting joints must match expansion joints.

8.2.26 Beacon rails are recommended to be installed parallel to the long side of the wall on cement-sand mortar marks with orientation to the mark placed on the wall. In this case, the first row of rails should be placed at a distance of 0.5-0.6 m from the wall opposite the entrance to the room, and next rows- parallel to the first at a distance of up to 3 m.

8.2.27 In places where the floor should have a slope towards ladders or channels, beacon rails should be installed in such a way that the top of the rail has a given slope.

8.2.28 Immediately prior to placing the concrete mixture, the underlying layer should be moistened with plenty of water so that at the time of laying it is wet, but there is no accumulation of water on it.

8.2.29 The concrete mixture should be laid between the beacon rails in strips through one. At the same time, the thickness of the leveled concrete layer, taking into account its subsequent settlement during vibration treatment, should be taken 3-5 mm above the lighthouse rails.

8.2.30 With a concrete floor covering thickness of up to 100 mm, it is recommended to compact the concrete mixture with a vibrating screed, and with a greater thickness, it is necessary to pre-treat the laid concrete mixture with a deep vibrator before compacting with a vibrating screed. The speed of movement of the vibrating screed should be 0.5-1 m/min with the number of passes 1-2.

8.2.31 Concreting is recommended to be carried out without technological interruptions. Otherwise, before resuming concreting, the hardened vertical edge of the previously placed concrete must be cleaned of dirt and dust and washed with water. In places of working joints, compaction and smoothing of concrete should be carried out until the joint becomes invisible.

8.2.32 The skipped lanes are concreted after the removal of the lighthouse rails, using the concreted lanes as formwork and guides.

8.2.33 Vacuuming of concrete is carried out using a set of equipment, including: a vacuum unit, suction mats, a vibrating screed, smoothing machines, guides for vibrating screeds, hoses and connecting devices, containers for washing suction mats.

8.2.34 When using the vacuum method, the recommended concrete mixtures should have an increased sand content by 150-200 kg per 1 m 3 of the concrete mixture compared to the compositions according to table 8.2.2.

8.2.35 Concrete mixtures used when using the vacuum method should have a draft of 8-12 cm. The increased water-cement ratio facilitates the laying and compaction of the mixture, and also allows you to get a more even floor covering.

8.2.36 The technological regulations for the manufacture of floor coverings by the vacuum method provide for laying mats with vacuum cavities on the vibrocompacted surface of the floor covering, connecting them with hoses to a vacuum pump and suction of excess water, thereby increasing the strength and uniformity of concrete.

8.2.37 Suction mats are laid on the freshly laid concrete mix with an overlap of 10-15 cm on each side, when laying on hardened concrete - at least 20 cm. lower panels, then they should be overlapped by at least 3 cm), and the upper one is rolled out, starting from the middle. This order of rolling improves sealing. The panels must be laid evenly, without wrinkles and folds. The upper panel, in addition, after laying, it is recommended to iron it with a roller, brush, etc.

8.2.38 The vacuum unit at idle must create a vacuum of the order of 0.09-0.095 MPa. The normal operating vacuum of a vacuum pump is 0.07-0.08 MPa.

The duration of the evacuation increases inversely with the drop in vacuum. At a rarefaction of less than 0.06 MPa, evacuation should not be performed. The evacuation time is calculated on the basis of 1-1.5 minutes per 1 cm of the concrete coating thickness. The end of the process is judged by the termination of the flow of the water-air mixture into the pipeline.

8.2.39 After the end of the vacuuming process, it is necessary to roll up the top panel so that the filter panel is open by 1-2 cm from both sides with the vacuum pump turned on for 10-15 seconds. Then the top panel is completely folded.

8.2.40 In order to improve the evenness and smoothness of the surface of concrete floor coverings after compacting the concrete mixture and setting it to a state where light traces remain on the surface during walking, it is necessary to carry out the primary treatment of the coating - grouting with concrete finishing machines with leveling discs. The secondary processing of the coating - with concrete finishing machines with blades - is carried out no later than after 6 hours.

8.2.41 When using the vacuum method, the primary smoothing of the concrete surface is carried out immediately after the end of vacuuming, and the secondary treatment is carried out after 3-5 hours.

8.2.42 To increase the resistance of concrete floor coverings to mechanical stress, reduce dust separation and reduce water permeability, it is recommended to harden the surface of the coatings with dry mixes or impregnate the coatings with polymeric materials. A combination of these techniques is also possible. The use of colored reinforcing mixtures makes it possible to obtain colored concrete floor surfaces.

8.2.43 Concrete pavement with a hardened top layer is recommended to be made at least 70 mm thick.

8.2.44 The device of a hardened top layer can be provided for by a coating made as traditional way, and with the use of vacuum.

8.2.45 For hardened concrete floor coverings, concrete of the following compositions is recommended, wt. hours:

8.2.46 Dry mixtures used for hardening concrete pavements must contain Portland cement grade not lower than M400 and wear-resistant filler, which can be used as metal powders, corundum, quartz, etc., as well as modifying additives. As such a mixture, it is recommended to use a hardening mixture of the Mastertop brand according to TU 5745-003-40129229-01.

8.2.47 The application of hardening mixtures is carried out on the wet concrete surface of the concrete pavement, that is, before the stages of grouting and smoothing. When hardening concrete coatings made with the use of vacuum, the application of the hardening mixture is carried out immediately after vacuuming.

8.2.48 Before applying the hardening mixture, the concrete must be smoothed to soften the crust formed on the surface. After the appearance of moisture on the smoothed surface of the concrete, a dry mix should be applied to the concrete manually or using a mechanical distributor. The consumption of the hardening mixture is 5 kg per 1 m 2 of the coating surface.

8.2.49 It is recommended to apply the hardening mixture in 2-3 steps. At the beginning, 2/3 of the total amount of the mixture is applied. The mixture must be completely evenly saturated with moisture sucked from the concrete, as judged by the uniform darkening of the mixture. The addition of water to the hardening mixture is not allowed.

8.2.50 The smoothing of the surface is carried out by a concrete finishing machine with a disk, which excludes the formation of bubbles and shells. Areas that cannot be troweled by machine must be troweled by hand. After applying the remaining mixture, smoothing is repeated.

8.2.51 Finishing the hardened surface should be done with a machine with blades.

8.2.52 No later than 2 days after the coating is applied, expansion joints should be cut using joint cutters with a diamond disc. When using non-removable rail molds, the grooves in the upper part of the rail molds are used as expansion joints and the cutting of the joints is carried out only in the transverse direction.

8.2.53 Concrete coating after its installation must be kept in humid conditions (covering with polyethylene film, etc.) for at least 7 days, then natural drying is carried out. It is also possible to use compositions applied to a wet concrete surface and forming a film in order to prevent premature removal of moisture from the concrete. As a rule, one-component compositions based on acrylic dispersions are used as such compositions, in particular Master-Cur 113 sealant-hardener (MVT concern, Belgium). It is also recommended to use Rizopox 5601W water-dispersion epoxy paint (TU 2257-011-43548961-2002) and Rizopox 1301W water-dispersion epoxy primers (TU 2257-027-43548961-2003) and Koropox brands (Korodur, Germany). ).

8.2.54 The application of such compositions is carried out by roller immediately after the smoothing stage, with at least two layers of the composition being applied.

8.2.55 The use of the compositions specified in clause 8.2.54 to prevent premature drying of concrete on coatings on which polymer impregnation is planned is not recommended.

8.2.56 After the concrete has reached an air-dry state (moisture content not higher than 5%), expansion joints should be sealed by laying an elastic polyurethane cord into the formed groove and pouring it flush with a curable elastic urethane composition, which is recommended as a sealant "Gerteks" (TU 5770- 006-04002274-00). When performing expansion joints near columns and along walls, polyethylene foam gaskets should be removed and the resulting groove should be filled with a polyurethane composition.

8.2.57 When the concrete reaches an air-dry state, in order to reduce dust separation from floor coverings and their water and oil permeability, it is also possible to apply impregnating compositions, the compositions of which and application technologies are given in Chapter 9.

8.2.58 The operation of the floors is allowed after the concrete has acquired the design compressive strength, pedestrian traffic on these floors can be allowed if the concrete compressive strength is at least 5 MPa.

I. SCOPE

In all applications technological map it is necessary to link it to the local conditions of work, taking into account design features coating, type of substrate, method of cutting joints and concrete care.

II. MANUFACTURING PROCESS INSTRUCTIONS

Requirements for the readiness of previous work

Prior to the commencement of work on the installation of a cement-concrete pavement, a cement-soil base must be prepared and a longitudinal and transverse drainage system arranged.

The sand of the leveling layer should be taken out and planned out on the base and a geodetic breakdown should be made.

For the construction of expansion joints, boards are prepared from spruce, pine or linden (grades I and II), which, before installation: are immersed in water for 24 hours.

Pins 40-70 cm long are made of reinforcing steel with a diameter of 20-40 mm.

Work production technology (see figure) Formwork installation

Formwork boards with a thickness of at least 40 mm are installed along the edge of the coating, marked with pegs of geodetic stakeout. The formwork must be cleaned before installation.

Along the edge of the coating, at the joints of the formwork, wooden linings are buried in the sand so that their top lies at the level of the sole of the coating. The sand between the linings is planned and compacted, and then the formwork boards are installed on the linings, they are straightened in plan and in height and fixed with steel crutches or wooden pegs.

To create a reliable stop on the outside of the formwork, a soil roller with a width of at least 20 cm is poured and tamped.

In order for the upper edges of the formwork to have the design marks of the coating, the height of the boards must strictly correspond to the thickness of the coating.

The upper edges of the formwork must be even and smooth. The heads of the crutches that fix the boards should be planted below the upper edges of the formwork so that they do not interfere with the advancement of the template and the vibrating screed. At the joints of the formwork boards, the difference in marks should not be more than 2 mm.

After the final installation of the formwork, control leveling should be carried out.

Leveling and compacting the sand leveling layer

A sandy leveling layer on a cement-soil base is arranged using a template that is manually moved along the formwork.

Before the template, the sand is smoothed with trowels, and then finally leveled with a template. When laying out the leveling layer, workers should ensure that there is a 3-5 cm high sand bead in front of the template along its entire length. After leveling, the leveling layer is compacted with a surface vibrator.

The sand for the leveling layer device must be wet. If the cement-soil base was covered with sand during its installation, it can be used for the device of the leveling layer.

Technological scheme of the device of cement-concrete pavement at the traffic interchange by means of small-scale mechanization:

1 - formwork; 2 - template; 3 - surface vibrators; 4 - power plant; 5 - deep vibrator; 6 - vibrorail; 7 - portable bridge; 8 - portable awning; 9 - water tank; 10 - mobile toilet; 11 — trailer for PTR and pantry; 12 - trailer for workers

Installation of cement-concrete pavement, cutting joints and filling them with mastic

Prior to concreting, the inner edges of the formwork are lubricated with a clay-lime mortar and the expansion joint structures are assembled.

Expansion joint structures are installed immediately before the placement of the cement-concrete mixture so that they do not interfere with the passage of vehicles delivering the mixture.

The distances between the expansion joints are assigned in accordance with the instructions of the "Instructions for the installation of cement-concrete pavement of roads" VSN 139-68 / Mintransstroy.

The board of the expansion joint structure is fixed on both sides with pins, and then, in the process of concreting, a cement-concrete mixture is laid on both sides of the board and worked out with deep vibrators.

The cement-concrete mixture must meet the requirements of GOST 8423-63 "Road concrete" and have a draft of the cone within 2-3 cm. To increase the workability of the mixture, air-entraining and plasticizing additives (abietin resin, sulfite-alcohol stillage) should be introduced into it during preparation.

The cement-concrete mixture is delivered in dump trucks with rear unloading and unloaded directly onto the leveling layer. To the place of unloading cars are served in reverse. If it is possible to organize traffic along the side of the road, dump trucks with side unloading are used.

The place of unloading of the cement-concrete mixture is appointed by calculation. With a coating width of 4.5 m and a thickness of 22 cm, approximately 2 vehicles of the ZIL-MMZ-555 type should be unloaded for every 3.5 m of the coating (assuming that one vehicle delivers 1.7 -1.8 m 3 of the mixture).

Damage to the leveling layer, made by the passage of the car, is smoothed out by workers with trowels. The concrete mixture is distributed over the base with shovels without transferring.

The cement-concrete mixture laid flush with the upper edges of the formwork is compacted with deep and then surface vibrators. Near the formwork and at the expansion joints, the concrete mixture is worked out with a deep vibrator especially carefully. To protect the mace of the vibrator from breakage, a limiter must be placed on it, which does not allow the mace to sink to the cement-soil base.

At the locations of the compression joints, pins made of smooth reinforcing steel with a diameter of 18 mm and a length of 50 cm are immersed in the concrete mixture.

For the exact location of the pins, a template and a vibrator are used.

The surface of the concrete pavement is finished with a vibrating screed, the profile of which must correspond to the design profile of the pavement.

The upper faces of the formwork are cleaned from the concrete mixture. The vibrating screed is moved along the concrete surface at a speed of 0.5-0.8 m/min, while the edges of the vibrating screed must slide along the upper edges of the formwork. In front of the vibrating screed, workers add the missing concrete mixture with shovels or remove its excess.

If, after the passage of the vibrating screed, dents and shells appear on the surface of the coating, a concrete mixture is added to these places and the surface of the coating is re-treated with a vibrating screed.

When processing the surface of concrete at the laying of the seam, the vibrating screed is brought close to the seam, and then transferred to the other side of the seam and the concrete surface is continued to be processed. Finally, the surface of the coating at the mortgage board is smoothed with a grater, and then with a nylon brush. After the concrete has begun to set, the laying board is carefully removed and the joint is processed and poured in the same sequence as the compression joint.

After processing the concrete with a vibrating screed, the shells are sealed with a grater, the cement milk is removed with a nylon brush and the coating is smoothed with a long-handled trowel.

The evenness of the coating is checked with a rail 3 m long, which is installed on the coating parallel to the longitudinal axis of the coating in several places. In places where: gaps under the rail exceed 5 mm, add a cement-concrete mixture and repeat the treatment with a vibrating rail and trowels.

The finished concrete surface is treated by moving the nylon brush from the axial seam to the edge. When working with trowels and nylon brushes, they should be systematically cleaned and washed in water.

The edges of the coating are given an oval shape by processing them with a special grater.

When processing the surface of concrete, the edges of the coating and the seams, it is strictly forbidden to wet the concrete.

For the convenience of working on the surface of concrete and seams, workers use portable wooden bridges.

Compression joints are placed in freshly laid concrete. To do this, at the locations of the transverse compression joints, previously marked on the formwork, a cord is pulled or a guide rail is installed and 8 mm thick embedded boards are immersed into concrete in a vertical position to a depth of 5-6 cm. The top of the embedded boards should rise 4-5 cm above the concrete surface. On both sides of the embedded boards, the concrete surface is treated and rubbed with a grater so that the edges of the future seam are at the same level.

After the concrete begins to set, the embedded boards are carefully removed, the seams are treated with a grater and filled with hot bituminous mastic from a watering can.

The finished concrete surface is covered with a mobile awning or, after the disappearance of the water film, with a damp burlap. After 3-4 hours, the burlap is removed and the concrete is covered with sand with a layer of 6 cm, which is constantly moistened for 20 days.

The finished area of ​​​​the coating for the time of concrete hardening and care is protected by barriers and warning signs.

The formwork is removed after 8-24 hours, depending on the air temperature. First, remove the pins, and then carefully separate the formwork from the concrete with a crowbar. The formwork boards are removed, cleaned and transported to a new installation site, and the side edges of the coating are covered with wet sand.

After the end of the concrete hardening period, the surface of the coating is cleaned of sand, cut off the excess bituminous mastic on the seams with a special spatula and, if necessary, add bituminous mastic to the seams.

Basic quality requirements

The finished cement-concrete pavement must meet the following requirements:

The surface of the concrete should be even, without cavities, and the edges of the coating and the edges of the joints should have an oval shape. Concrete should be well worked out, there should be no shells on the side faces of the coating.

Permissible deviations from the design dimensions are:

across the width of the coating ………………………………….. ±5 cm

by thickness…………………………………………………. ±10%

along the transverse slope……………………………….. ±0.5%

Safety instructions

Workers working with vibrators and vibrating screeds must be trained in the use of electrified tools, and are familiar with the safety regulations.

All wiring cables connecting step-down transformers with PES and electric vibrators must be insulated. If the electric cable is exposed or broken, the vibrators are damaged, the workers must immediately report this to the electrician (TPS driver).

Warning and fencing signs to ensure the safety of work should be posted at work sites.

During the evening shift, the work area should be well lit.

During the construction of cement-concrete coatings, it is necessary to comply with the requirements of the following regulatory documents:

1. Building codes and regulations, part III, section D, chapter 5. Highways. Rules for the organization and production of work. Acceptance into operation. SNiP Sh-D.5-62. Gosstroyizdat. Lee, 1963.

2. Instructions for the installation of cement-concrete pavements for highways, VSN 139-68 / Mintransstroy, Transport, M., 1968. Mintransstroy

3. Safety regulations for the construction, repair and maintenance of highways, Transport, M., 1969.

III. INSTRUCTIONS FOR THE ORGANIZATION OF WORK

To perform a set of works on the installation of a cement-concrete pavement at a traffic intersection, replaceable grips are planned, on which the following work is performed:

a) formwork installation and leveling layer layout;

b) sand compaction of the leveling layer, installation and maintenance of the cement-concrete pavement;

c) removal of the formwork and backfilling of the edges of the coating with wet sand.

The necessary auxiliary materials and devices are concentrated at the work site: formwork boards and pins for fixing them, materials for lubricating the formwork, expansion joint designs and boards for working joints; plug-in rails and mastic for pouring joints and sand for covering concrete, a mobile bridge, an awning for covering concrete, as well as a set of tools and small-scale mechanization tools (vibrator, vibrators, templates, etc.).

Near the work site there are wagons for workers to rest and shelter from inclement weather, a chest for storing tools, a container with water for a technical purpose, tanks with drinking water, a first aid kit with a set of essential medicines.

The work on the installation of cement-concrete pavements is carried out by an integrated team consisting of three units.

The installation of the formwork and the layout of the leveling layer under the template is carried out by a link of workers consisting of:

Concrete worker 3rd category - one

Concrete workers 2 category - 2

One concrete worker 3 size. and one 2 times. formwork is installed, and the second concrete worker 2 razr. plans the sand under the pattern.

In the process of work, the link allocates one concrete worker. 2 bits for removing formwork in areas of hardened concrete and backfilling the edges of the coating with sand.

Sand compaction of the leveling layer, concrete pavement and joint cutting are carried out by a team of workers consisting of:

Concrete workers 4 size - 2

Concrete workers 3rd category - four

Concrete workers 2 category - 3

Road workers 1 category - 2

Power plant engineer 4th category. - one

Concrete worker 3rd category compacts the sandy leveling layer with a surface vibrator, levels it after the passages of vehicles delivering the cement-concrete mixture and distributes the cement-concrete mixture.

Three concrete workers 2 size. receive and distribute the cement-concrete mixture.

Concrete worker 3rd category compacts the cement-concrete mixture with a deep vibrator.

Two concrete workers 3 size. (one on each side of the coating) finish the concrete surface with a vibrating screed.

Two concrete workers 4 size. perform the final finishing of the concrete surface, the arrangement of seams and the finishing of the edges of the coating.

Concrete care is performed by a link of workers consisting of two road workers of the 1st category. Their duties include covering the concrete with an awning or damp burlap, removing the burlap, and filling the concrete with sand.

Power plant engineer 4th category. maintains mobile power station and vibrators.

IV. SCHEDULE OF PRODUCTION OF WORKS ON THE DEVICE OF CEMENT CONCRETE
4.5 m WIDTH, 22 cm THICK COATINGS WITH LOW MECHANIZATION

V. CALCULATION OF LABOR COSTS FOR THE DEVICE OF 248 m 2 CEMENT CONCRETE COATING 4.5 m WIDTH, 22 cm THICK MANUALLY BY MEANS OF SMALL MECHANIZATION

VI. MAIN TECHNICAL AND ECONOMIC INDICATORS

VII. MATERIAL AND TECHNICAL RESOURCES

a) Basic materials and semi-finished products

b) Cars

c) Tools and fixtures

The technological map was compiled by the Department for the introduction of advanced labor methods and technical regulation in the construction of roads and airfields of the Orgtransstroy Institute (performed by engineer T.P. Bagirova) based on materials from the Kharkov regulatory research station /

The second edition, revised with recalculation for new tariff rates. (Recalculation was made by engineer A.A. Kholodkova).

In the construction of monolithic cement-concrete pavements, a set of machines is used, which makes it possible to mechanize all production processes and organize the construction of the road by the in-line method. When organizing the construction of cement-concrete pavements in-line, the scope of work is divided into separate sections, based on the convenience of the machines included in the kit. The dimensions of the sections (captures) depend on the nature of the mutual linking of the machines with each other in work, which determines the whole system of organizing the construction of the coating as a whole.
As mentioned earlier, monolithic cement-concrete coatings can be one- and two-layer. On urban highways and high-speed roads, such coatings are laid on foundations made of soil reinforced with binders, as well as on gravel and crushed stone foundations. On streets with low traffic intensity, intra-block passages, it is allowed to arrange cement-concrete pavements on sandy bases. In the case of the use of sandy bases, as well as frost-protective and drainage layers of sand, work is carried out in the following sequence. Sand is brought in by dump trucks and distributed by a bulldozer or motor grader to the required vertical mark. After leveling, the sand is compacted by rollers on pneumatic tires.
The preliminary leveling of the sand layer is carried out by an autotrader, and the final leveling and compaction is carried out by a base profiler after the installation of the rail forms. The base or underlying layer should be compacted at the optimum moisture content of the sand, therefore, if necessary, before the passage of the profiling mechanisms, the sand is moistened with a watering machine.
The technological process of building crushed stone and gravel bases consists of the removal of materials by dump trucks, leveling with bulldozers or motor graders and compaction by rolling. It is advisable to use crushed stone laying machines in this case. When laying foundations from soils reinforced with binders, the production process can be carried out according to the mixing method in installations or according to the mixing method on the road. The technological sequence of operations is determined in this case in accordance with. the current "Guidelines for the use in road and airfield construction of soils reinforced with binders".
The technological process of setting up a cement-concrete pavement on a finished base with a set of concrete-laying machines includes the following operations: preparation of the base for rail-forms and installation of rail-forms; final layout and compaction of the base; surface treatment of the base (if it is made of cement-sand mixture) bituminous emulsion: installation of gaskets, pins of expansion joints, blocks for water intake wells; distribution of concrete mix; when installing two-layer coatings, after spreading the lower layer of the coating, a reinforcing mesh is laid, and then the concrete mixture of the upper layer is distributed; compaction of the concrete mixture and surface finish of the coating; arrangement of expansion joints; removal of rail molds; curing; filling expansion joints.

On fig. 105 presented technology system flow on the installation of monolithic cement-concrete pavements of urban roads with a set of concrete-laying machines moving along rail-forms. Rail molds can be installed on widened pavement bases. If such a base does not provide a non-sag position of the rail forms under the load from the machines of the concrete paving set, then a reinforced base must be arranged under the rail forms. Rail-forms must have strength and rigidity to ensure the passage of machines used for coating without deformation on them.
Before installation, check the condition of the rail forms and the correctness of the geometric dimensions. Curvature of the rail molds in the vertical plane should not exceed 2 mm, in the horizontal plane 5 mm. The difference in the height of the rail-form links at the joints should not exceed 2 mm. The rail molds must be cleared of old concrete. Deformed and faulty rail molds are rejected and not allowed for use.
Rail-forms are transported to the place of laying by cars or tractor carts. The rail-forms are installed in the design position by truck cranes with the expectation of a two-shift operation of the concrete paving machine. The breakdown of the rail-form installation line in the plan is carried out on one side of the coating using a theodolite, on the other side - according to a template. Installation of rail-forms in height is carried out according to design marks using a level.
The correctness of the installation of the rail forms is checked with geodetic tools, and the parallelism is checked with a template. The links of the rail-forms are connected with bolts, fastened to the base with metal pins.
Before the start of laying the concrete mix, the rail-forms must be run in, for which a concrete distributor with a bunker filled with sand is passed through them at least twice. All detected drawdowns are eliminated. The difference in height marks of two adjacent rail forms should not exceed 2 mm.
The mechanization of processes for the final compaction of sandy bases, frost-protective, draining and leveling layers is carried out by profilers DS-502A (B). The DS-502A profiler is manufactured in four modifications: for a flat profile device with a width of 3.5; 5 and 7 mm and for the installation of a gable profile with a width of 7 m. The DS-502B machine is designed for a strip width of a flat profile of 7.5 and 3.75 m, a gable profile of 7.5 m. Technical specifications base profilers are given in Table. 70.
When the profiler moves, the blade of the machine cuts off the unevenness of the base and accumulates a prism of material in front of it, filling up the depressions and giving the surface evenness and the necessary transverse slopes. The base is compacted with the help of a vibrating beam made in the form of a box-section beam, on the top panel of which vibrators with circular vibrations are mounted.

To reduce the coefficient of friction of the coating on the base, a leveling layer of sand treated with bitumen or cement is arranged. The work on profiling and compaction of this layer is also carried out by the DS-502A (B) machine.
After completing the final finishing of the base, gaskets with pins for expansion joints and structural elements of compression joints are installed. The normal operation of the joints between the plates depends not only on the design of the pin joints, but also on the thoroughness of the work performed during the construction process. If the seams are arranged in compliance with all technical rules, then for many years of operation of the road there will be no difficulties and only routine maintenance of the seams will be required. Improper work can lead to the rapid appearance of deformations, the correction of which will be costly.
In the practice of building main roads with cement concrete pavements in our country, for fastening gaskets and pins, supporting basket frames made of reinforcing steel with a diameter of at least 6 mm are used. In this case, the groove above the wooden spacer can be created in both freshly laid and hardened concrete.
In addition to these methods, when installing plank pads in the seams of concrete pavements, the method of fixing the pads with pins driven into the base on both sides of the board is used. After concreting, the pins must be removed, since the remaining pins anchor the concrete pavement to the base and, as a result, additional stresses appear in the concrete.
Simultaneously with the installation of the elements of the seams on the pavement of the roadway in the places provided for by the project, the structures of the manhole blocks of the water intake wells are installed. Blocks of wells are installed by truck cranes.
During the construction of reinforced concrete pavements, an additional operation is the laying out of reinforcing meshes or a frame. Reinforcement is prepared centrally at the production enterprises of urban road construction. Reinforcing meshes and frames are delivered to the place of laying on cars and installed in the design position by a crane on a car.
Before starting the laying of the concrete mix, the following is checked: a) the correct installation of the rail forms (their correct position in plan and longitudinal profile, the reliability of fastening the butt joints of individual links), the thoroughness of the lubrication of the side walls of the forms; b) reliable fastening of gaskets and pins in expansion joints; c) the sufficiency of wetting the leveling layer of untreated sand or sandy base.
The concrete mixture is transported to the place of laying in dump trucks with special bodies (with side unloading), which ensure convenient and quick unloading of the mixture into the distributor. The bodies of dump trucks must be waterproof, have serviceable closures and a smooth surface, devices for sheltering the mixture from drying out or moistening. After each trip, the bodies of dump trucks must be washed with water.
The duration of transportation of the concrete mixture on Portland cement with the onset of setting of at least 2 hours should not exceed: 30 minutes at an air temperature during concrete laying from +20° to + 30°C; 60 min - at air temperature below +20°. At air temperature from +30 to +35°С, relative air humidity less than 50% and concrete mixture temperature not more than 30°С, the duration of concrete mixture transportation should not exceed 30 minutes. The mobility (rigidity) of the concrete mixture should be assigned taking into account the time of its transportation to the place of laying and the air temperature. To maximize the use of a set of concrete placing machines and obtain concrete of a homogeneous composition, the concrete mixture must flow evenly and continuously throughout the work shift.
In Russia, a series of ZIL-MMZ-553 concrete trucks has been produced, designed to transport concrete mix in hot climates. This machine, made on the basis of the ZIL-164A car, differs from the dump truck in the body structure, which has the shape of a gondola with a steeply inclined rear wall. The angle of inclination of the bottom to the horizon reaches 80°, and the rear wall - 48°. The bottom of the oval shape and the side walls of the body have air gaps 80 mm thick. The body has a protective cover, which opens at the time of loading.
Reception of the concrete mixture from vehicles (dump trucks) and its distribution over the base of the coating are carried out by the hopper of the concrete mixture distributor DC-503A (B). Table 71.

Concrete mixture from dump trucks is unloaded into a distribution hopper, which distributes it over the base, moving across the roadway. By adjusting the height of the hopper under the base, it is possible to change the thickness of the laid concrete layer. The required increase in the thickness of the uncompacted layer of the concrete mixture against the design thickness of the coating is determined empirically, depending on the speed and plasticity of the mixture. With a cone draft of 1-2 cm, this increase is 2-3 cm.
A more efficient distribution of the concrete mix is ​​achieved by using concrete mix screw distributors. The DS-507 auger distributor, created in Russia, is designed for distribution and preliminary compaction of the concrete mixture over a strip 7.0-7.5 m wide. The main working body of the DS-507 machine - a reversible auger - consists of two halves, each of which has an independent drive. There are two blades in front of the auger, which cut off excess mixture and contribute to its uniform distribution. Both the auger and blades can be set to the desired height using the lift cylinders. The second working body of the DS-507 concrete distributor is a vibrating beam, which performs preliminary compaction of the distributed concrete mixture. The vibrobeam is made in the form of a welded beam, on which six mechanical vibrators are installed.
When constructing a two-layer coating, first lay the concrete of the lower layer with a thickness of 2/3 of the total thickness of the coating, then lay the prefabricated welded reinforcing mesh and the second layer of concrete. In this case, it is recommended to use two distributors for separate placement of the concrete mixture in the lower and upper layers of the pavement.
The organization of work on the construction of a two-layer pavement should ensure the rhythmic laying of the mixture with the expectation of obtaining a homogeneous monolithic and dense concrete throughout the entire thickness of the pavement. In this regard, the gap in time between laying the lower and upper layers at an air temperature of 5 to 20 ° C should be no more than 1 hour; at a temperature of 20-25 ° C - no more than 40 minutes and at a temperature of 25-30 ° C - no more than 30 minutes. It is necessary to complete work on the construction of a two-layer coating section with the calculation of laying the upper and lower layers at the same time.
After the passage of concrete-laying machines, leveling, compaction and finishing of the coating is performed by a concrete finishing machine DS-504A (B). The technical characteristics of concrete finishing machines DS-504A and DS-504B are given in Table. 72.

AT recent times A new rail concrete finishing machine DS-508 was created, which, together with a concrete mix distributor DS-507, is designed for laying road concrete in a pavement 7 and 7.5 m wide, mainly on stabilized soil foundations.
Concrete finishing machine DS-504A(B) moves along the rail-forms behind the distributor and performs work with three working bodies - a compacting paddle shaft, a vibrating beam and a screed.
The paddle shaft is located at the front (in the direction of travel) of the concrete finishing machine. When the shaft rotates, the blades evenly distribute the concrete mixture over the width of the strip being laid and partially compact it. Behind the shaft there is a vibrating bar, which, making oscillating movements, finally compacts the laid concrete mixture.
The screed of the machine consists of two screeds - the front vibration and the rear screed. Both beams perform swinging movements across the roadbed, sliding on the surface of the laid concrete. Thanks to the rocking movements of the beam, the surface of the concrete is finally leveled and smoothed out. The coating is finished in 1-2 passes in one place when the machine moves forward. On the reverse run, the machine rises to the transport position, leaning on the running wheels. For good compaction and surface finish of laid concrete, correct installation working parts of the machine. A self-propelled concrete finishing machine is operated by one driver.
During the construction of monolithic coatings with a set of wheeled vehicles, the rail-forms are removed by a crane no earlier than 24 hours after the concrete has been laid, after the concrete has gained the required strength, which is established empirically. The removed rail-forms are transported to the beginning of the stream, where they are installed in a new section by the same crane.
The most efficient machines for paving road concrete are trackless machines that move along the roadbed under construction on caterpillar tracks. Precise observance of the design arrangement of the concrete pavement in plan and profile is achieved in this case with the help of automatic tracking systems. The trackless paver differs from the rail machines also in that it has a single pass and is equipped with working elements for spreading, compacting and finishing concrete.
The main advantage of trackless pavers, or slipform pavers as they are called, is their high productivity due to single pass, as well as the fact that their use eliminates the extremely laborious, inefficient work of installing and dismantling rail forms.
Sliding forms are mounted between the tracks of the stacker. The distribution of concrete unloaded in front of the machine by dump trucks is carried out by auger or paddle working body. The frame with paddles can be lowered and raised by a hydraulic cylinder, moved on a cross tube carriage and thus evenly distributes the mixture across the entire width between the sliding forms.
For profiling the coating, a transverse beam is used - a slab with a pallet about 2 m wide. In front of this slab, the concrete mixture is compacted by rod electric vibrators immersed in concrete up to half the thickness of the coating. The top layer of concrete is additionally compacted with a vibrating tube mounted directly in front of the profile beam. The surface of the coating is leveled with a transverse slab with a pallet width of 0.7 m. Finally, the surface of the coating is smoothed out by a floating transverse beam with a pallet width of 0.4 m.
The paver may have a mechanism for making a longitudinal seam by inserting an elastic spacer into the freshly laid concrete. The control of the concrete paver is automated. To maintain the given direction of movement of the machine and the evenness of the surface of the coating, a tracking system is used. One of the designs of this system consists of two base wires stretched on metal racks with holders adjustable in height. The wire base is installed on both sides of the carriageway at least 100 m ahead of the concreting of the pavement. The installation is checked by leveling with an accuracy of ± 2 mm. Four electronic sensors are mounted on the paver frame to maintain a given level of the surface of the coating and one sensor for the direction of movement of the machine. Each sensor has a slot through which the base wire passes. There are microswitches on both sides of the slot.
When the movement of the machine deviates from the given direction or when the position of the working bodies deviates from the set level, the wire is pressed on one of the microswitches, as a result of which the relay system for turning on the electric motor of the reversing mechanism is activated to correct the direction of movement or the level of the position of the frame with the working bodies of the machine.
A sensor for maintaining a given direction of movement of the machine is suspended on the front corner of the machine frame. The adjustment is made according to the difference in the speeds of movement of the tracks of the machine, which have an independent drive. The position of the frame with working bodies is corrected by four sensors suspended on brackets in front and behind the machine.
With reliable bearing capacity base, this system ensures the evenness of the surface of the coating with a gap under the triple rail of no more than 3 mm.
It should be noted that the slipform paver performs the complex operations of laying, compacting and finishing the pavement and eliminates the use of special concrete finishing machines. One of the caterpillar slipform pavers mastered by our industry is the DS-513 paver. At present, our industry has mastered the production of a set of machines DS-100 with sliding forms for high-speed construction of highways (Fig. 106). Such machines can be used for the construction of urban highways. long distance, approaches to big cities, ring (around the city) highways.

The DS-100 set includes nine main types of machines and equipment: subgrade and foundation profiler DS-97; conveyor loader DS-98 mounted to the profiler; concrete mix distributor DS-99; concrete paver DS-101; DS-103 trolley for transportation of reinforcing mesh trailed to the concrete distributor; vibratory loader DS-102 of reinforcing mesh trailed to the concrete paver; concrete finishing machine - tubular finisher DS-104; DS-105 machine for applying film-forming materials; asphalt-laying equipment DS-106.
In addition to the main ones, the set includes auxiliary machines: cross cutter DS-112; cutter of longitudinal seams DS-115; filler of joints DS-67; DS-107 trailer with MAE-537 tractor for transportation of machines and equipment of the set.
The kit also includes an automated continuous concrete plant SB-109 with a capacity of 120 m3/h. For the normal operation of a set of vehicles with a rate of at least 1 km of road per day, it is necessary to have two such plants.
Profiler DS-97 is used for loosening, distributing and profiling the top layer of the subgrade, as well as profiling various imported materials (sand, slag, gravel, gravel-sand mixtures, soils reinforced with binder materials, etc.) when installing frost-protective, draining and underlying layers and various bases for cement-concrete coatings. The working bodies of the profiler are the auger-mill, the front blade, the distribution auger and the rear blade. A vibrating beam can be additionally mounted on the profiler for compacting the structural layers. Travel speed of the profiler during preliminary profiling (scarring with a cutter) 1-2 m/min, during finishing profiling 6-7 m/min, when distributing materials 3-5 m/min, when arranging a stabilized base (mixing in place) 8-12 m /min and when spreading reinforced soil with simultaneous compaction 1-2.5 m/min. The width of the processed strip is 8.5 m, and with dump extensions - 9.5 m. The level and direction indicators in terms of the profiler and other machines are copy cords (strings).
Hinged conveyor-loader DS-98, consisting of a fan-type belt transport, is designed for reloading excess material to the roadside or to vehicles.
The DC-99 concrete distributor is used to receive concrete mix and other materials from vehicles (usually dump trucks) and distribute them evenly over a width of up to 7.5 m and a thickness of up to 50 cm. The working bodies of the concrete distributor are laying equipment, including a frame, receiving hopper with a belt conveyor and a mechanism for moving the hopper; distribution equipment, including a screw cutter and a dosing gate. Speed ​​of movement of the DS-99 car at distribution of concrete mix of 2-4 m/min. When constructing a reinforced cement-concrete pavement, a DS-103 trolley is attached to the distributor for transporting a reinforcing mesh (up to 7.35 m wide).
An additional replacement equipment for the concrete distributor or profiler is the DS-106 asphalt paver, which is also used for laying stabilized and other mixtures. In this case, on the concrete distributor, as well as on the profiler, a vibrating beam can be mounted to compact the laid mixtures.
Asphalt paver DS-106 consists of a semi-trailer pneumatic hopper and a screed hung in front of a concrete distributor or profiler. The bunker performs the role of not only a receiving, but also a distributing and dosing device with a rear wall adjustable in height.
The DS-101 concrete paver performs operations on the final distribution of the concrete mixture, semi-automatic laying of reinforcing bars along the axis of the machine and from the sides of the coating to connect concreted strips, the device of a longitudinal seam in freshly laid concrete with filling it with insulating tape and preliminary finishing of the coating. The working parts of the paver are a distributing auger, a first metering gate, a package of internal vibrators, a second metering gate with electromagnetic vibrators, two oscillating forming beams, a screed and side sliding molds. Working bodies and sliding forms are mounted on an auxiliary frame, which is attached with special pins to the main frame of the concrete paver. Stacker travel speed up to 3.2 m/min.
When constructing mesh-reinforced coatings, the concrete paver is equipped with a reinforcing mesh vibrator DS-102. The vibratory loader is mounted on a semi-trailer two-support pneumatic wheel frame and is attached to the concrete paver using special rods. Two sections of vibrators are attached to the frame with the help of an adjustable shock-absorbing suspension; the vibration of each section is carried out by two mechanical vibrators. The mesh immersion depth is regulated by two hydraulic cylinders.
The paver is equipped with additional equipment: a device for forming the edges of the coating; vibratory cutter of a longitudinal seam in freshly laid concrete; device for laying reinforcing pins.
Concrete finishing machine - tubular finisher DS-104 is designed for final finishing of the surface of the cement-concrete coating. The main working body of the machine is a smoothing thin-walled pipe, consisting of two sections and located diagonally in relation to the direction of movement of the machine. The screed pipe is equipped with a water spray system for wetting the surface of the coating during its finishing. Finishing of a covering is carried out by shuttle passes for 3-4 times.
The DS-105 machine for applying film-forming materials to the surface of concrete is equipped with a tank with a stirrer, a pump for pumping liquid and a spray device. The machine moves at a speed of up to 10 m/min, applying a thin layer of a moisture-proof film on the surface of the coating or laying out a roll of synthetic film to a width of 3.65 to 7.92 m.
The cutter of transverse seams DS-112 is mounted on a self-propelled pneumatic wheel trolley. The cutter has two carriages (each with two cutting discs) as working elements, which move simultaneously along the frame, cutting transverse seams in hardened concrete.
The DS-115 seam cutter is a four-wheeled trolley with a working body installed on it - a three-disc cutter for cutting longitudinal seams in hardened concrete.
Transportation of the entire set of DS-100 and auxiliary machines and equipment is carried out by two DS-107 trailers with a MAZ-537 tractor.
The set of machines DS-100 for high-speed construction of roads with cement-concrete pavement is designed for an annual output of 50-75 km, so the efficient use of machines can be achieved only if the subgrade is prepared in advance, vehicles are provided (heavy-duty dump trucks of the KrAZ-type 256B) and uninterrupted supply of inert materials and cement to factories preparing cement-concrete mixtures.