Mixes for concrete repair outdoors. Repair mixes for concrete: varieties and choices The best mix for concrete repair on the street

The process of solidification of all binders in the air is accompanied by an inevitable process of shrinkage.
Deformations that occur in the process of reducing the volume of the cement mixture can cause cracks in the finished concrete, which will not only adversely affect the appearance of the structure, but also violate its solidity, significantly reducing the operational period.
To correct the situation by restoring the solidity of the concrete structure, dry repair mixtures applied to the places of destruction of the concrete layer are capable. This dictated the need to use concrete repair mixtures.

Features of our concrete repair mixes

Buying dry mixes for concrete, instead of alternative repair options, the client not only saves his own time, but also the budget. The reason for this is the optimal ratio of price and quality of our products, which allows to achieve the first results within 24 hours from the moment of application, which is an order of magnitude faster than traditional analogues.
Among other things, the repair of concrete is accompanied by an increase in water resistance in the places where the mixture is applied. This effect is achieved due to the adhesion process that quickly proceeds between the damaged concrete and the multicomponent non-shrinking mixture.

As for the temperature regime, the concrete repair compound has high hardening rates, arriving in the temperature range from +5 to +80 degrees Celsius.

The shelf life of the consistency of the diluted mixture reaches 60 minutes, which is quite enough for spot application.

Advantages

By choosing our high-speed materials, the customer enjoys a wide range of benefits. Among them are:

• acceptable cost
• Possibility of delivery to the customer's address
• an impressive range of repair mixtures for damages of any type and size
• compliance of the materials sold with European quality standards, which acts as a guarantor of durability

Exposed concrete is subject to permanent exposure to snow, rain, sun. From season to season, structures experience temperature fluctuations, the magnitude of which can reach 100°C. Sadly, statistics show a very extensive experience of the fragility of the protection used.

Literally a year later, the seams and layers crack, leaks occur, and fluid accumulates in the protective layer. With the next freeze / thaw cycle, peeling of the finish coat may occur. Therefore, the most serious requirements are imposed on the complex of repair and restoration work.

Long downtime during concreting can cause poor setting of new and old concrete

Structures made on the basis of artificial stone are destroyed under the influence of the following factors:

• chemical reactions- arise due to an increase in the level of carbon in an artificial stone. They cause a violation of the proportions of the w/c ratio in the solution;
• chemical reactions that occur under the action of chloride ions. Chlorine is found in road salt, which affects reinforced concrete pavements. Reinforcement oxidation begins in the structure;
• moisture liquid is able to seep into the pores of concrete. At sub-zero temperatures, it crystallizes, which causes the destruction of concrete, cracking;
• mechanical loads- dynamic impacts, impacts exceeding the allowable loads work on the destruction of concrete;
• natural disasters, seismic activity, fires;
• carries a serious risk non-compliance with technological standards at the construction stage. Here we can talk about the formation of cold seams, which during operation damages the strength and aesthetics of the structure.

Purposes and methods of repairing concrete on the street

Repeated repairs carried out without observing the technology and with the participation of illiterately selected materials can lead to further degradation of the structure, loss of bearing capacity and significant financial costs.

Restoration of concrete structures should be well planned, taking into account the following goals:

• restoration of the bearing capacity of the structure;
• protection of fittings from corrosion;
• reinforcement of concrete by means of composite materials.

Repair steps can be summarized as follows:

• inspection of the concrete structure;
• identification of the causes that led to the destruction;
• planning of repair activities;
• selection of compositions and technologies;
• repair implementation;
• care;
• quality control.

Concrete floor repair materials

Objects can be industrial outdoor areas, beams, ceilings, roads and other surfaces that are subject to strong dynamic loads.

When choosing a material, the degree and nature of damage, the technical characteristics of concrete, and the specifics of operating conditions are always taken into account. It is necessary to monitor the compatibility of the repair composition and concrete, the degree of responsibility of the structure, the depth of destruction, the position and accessibility of the repaired surface.

Depending on the nature of the damage and the purpose of the repair, the following types of mixtures are used:

• repair compounds used to restore the bearing capacity of concrete structures;
• compositions for non-structural restoration. In this case, small defects are repaired and the surface is leveled.

In addition, it is customary to distinguish:

• compositions for anti-corrosion protection of fittings;
• materials for the repair of non-reinforced and reinforced concrete;
• waterproofing compounds;
• leveling compounds;
• epoxy resins for repairing cracks by injection;
• finishing protective and decorative coatings.

Thixotropic mixtures (materials for structural repairs)

These are dry mixes intended for the restoration of concrete and reinforced concrete structures on the street. The material is reinforced with polymer fiber and is characterized by compensated shrinkage. We can talk about a high degree of adhesion, water resistance, frost resistance, mechanical strength.

Thixotropic mixtures are applied manually or mechanically, in a layer of 10-35 mm. Thanks to its thixotropic characteristics, the working the solution works on vertical and horizontal bases, without requiring the use of stationary formwork.

Scope of application: mixtures are most often used for structural repairs (restoration of bearing capacity) of vertical and horizontal foundations, when smoothing open reinforcing bars, filling traces from formwork, repairing upper layers.

Fluid solutions

Scope of application: structural restoration of reinforced concrete columns, viaduct steps, floor slabs and beams, industrial floors, roads, filling gaps and cracks between slabs

These are dry mixes used for the repair of concrete by pouring into the formwork. This option is indispensable where, due to the specificity and depth of damage, a high fluidity of the solution is required. The material is used in the restoration of road surfaces, when filling areas between concrete structures, etc.

The thickness of the application layer is 10-40 mm. When mixing with water, a solution is formed that is resistant to abrasive loads, delamination, and low temperatures. Plus, waterproofing properties are realized.

Typical technical parameters

Solutions for the repair of concrete destroyed by corrosion of reinforcement

Such compositions are characterized by average strength and controlled shrinkage. They are used to repair concrete destroyed due to corrosion processes in reinforcement. Layer thickness 5-35 mm. Formwork is not required.

Solutions of this type can be applied to vertical surfaces. In order for all the properties of the material to be able to fully work on open concrete sites, it is recommended to use additional additives. The material is not suitable for structural repairs.

Scope of application: restoration of concrete destroyed by corrosion of reinforcement, balconies, beams, pillars, alignment of defects on vertical surfaces, in technological, rigid seams.

Typical Specifications

Compounds with fast curing

The aggregate size in grout mixtures can vary from 3 to 10 mm

These dry mixes not only quickly gain strength, but are also designed to eliminate serious defects. This is a good solution for heavily loaded bases where long downtimes are not possible (industrial facilities, roadways, runways, bridges). Some varieties can be used at low temperatures. Layer thickness 20-300 mm.

Gravy mixtures can be attributed to this group - they do not shrink and are characterized by rapid hardening. The material is necessary for high-precision grouting and installation of equipment, including outdoors.

Scope of application: repair of road, airfield pavements, where urgent work is required, repair of concrete industrial sites, filling of hard joints, installation of fences, concrete pillars.

Typical technical parameters

Anchor mixtures

It is a fluid, expanding concrete mix that quickly gains strength and is not subject to shrinkage. It is used for anchoring industrial equipment and fixing bases, filling technological cavities and seams.

Typical technical parameters

Injection solutions

To repair cracks, a cement binder can be used, on the basis of which an injection mortar is prepared.

The injection material is suitable for filling rigid joints, cavities, cracks, compacting foundations, strengthening structures

Typical technical parameters

Waterproofing materials

Compositions of this type are used for waterproofing and secondary protection of concrete structures.

The material can be divided into two groups:

• elastic compounds for protection against weathering and water load. These are ready-to-use two-component mixtures based on a special cement binder, synthetic polymers, and additives. After curing, a waterproof elastic layer with high adhesion is formed. The optimal application thickness is 2 mm;
• rigid waterproofing to protect structures in case of negative and positive water pressure. These are ready-to-use one-component mortars based on cement binder, fine sand, and additives. After mixing, a plastic solution is formed. In the cured state, a tough waterproof layer with high adhesion is formed. The optimal application thickness is 2-4 mm.

Typical specifications:

Rigid waterproofing layer is able to withstand pressure up to 1 atm

Equipment, tools and equipment

Professional equipment and tools are required at every stage of repair and restoration work.

A typical set that should be on site:

• base preparation equipment: in the open air, sandblasting or shot-blasting installations, high-pressure apparatuses (hydraulic installations), compressed air compressors are used. To connect the equipment, mobile power plants of the required capacity may be required. For jointing defects and cracks, perforators, jackhammers are used, the reinforcement is treated with metal brushes;
• equipment and tools for applying solutions: manual application may require spatulas, brushes, trowels. For mechanized application, shotcrete installations are used;
• equipment and tools for preparing solutions: concrete mixers are taken to work. You may also need a construction drill with a mixing nozzle, a shovel, a clean container, a measuring tool, devices for determining the viscosity of the solution and searching for reinforcement;
• means of individual protection, overalls.

Foundation preparation

The edges of defects, recesses are worked out with diamond disks, acting with the tool perpendicular to the surface. Work to a depth of at least 10 mm. With a needle gun or light perforators, concrete is selected from the defect.

The walls of the processing area must be vertical, the base itself rough and even. If the surface is smooth, create a roughness with recesses of at least 5 mm.

Concrete must be cleaned of cement laitance, paint, grease, oils. For final cleaning of the surface, compressed air of a compressor or high-pressure apparatus is used.

Surface cleaning can be implemented in several ways, depending on its actual state and working conditions:

• hydraulic method- the technology does not work in cases where it is required to exclude an increase in air humidity. Otherwise, it is a versatile and effective method that can be applied to almost any concrete;
• thermal- they work with burners when the concrete is heavily contaminated with petroleum products, rubber, oils. The method is effective at a small depth of damage (up to 5 mm). The heating of the base should not exceed 90 degrees;
• mechanical- one of the universal methods of preparation. Concrete is cleaned with sandblasting equipment, perforators, jackhammers, but mechanical processing is excluded where high dustiness should be avoided;
• chemical- an alternative to mechanical processing. The work site is treated with special compounds, after which it is washed with water.

Do not forget about cleaning the fittings from rust. To do this, use a metal brush to work manually or use a mechanized method (sandblasting).

With full exposure of steel, the gap between the surface and the rods should be at least 20 mm

If a thixotropic compound is applied, the prepared concrete must be damp. Excess liquid is removed with compressed air or a sponge. Good moisture should be achieved, but the substrate should not be wet.

Preparation of solutions

The technology of work depends on the type of mixture used. Of paramount importance is the amount of mixing water and the sequence of kneading.

Preparation of thixotropic solutions:

• for proper mixing of the working mixture, use the material in a whole container. The packaging is opened immediately before mixing;
• an accurately measured amount of water is poured into the concrete mixer (3.75 l - with manual application, 3.9 - with mechanical application);
• the mixer is switched on, after which the dry mixture is continuously introduced into it. The kneading lasts 1-2 minutes;
• the equipment stops for a minute, the walls are cleaned of adhering dry mixture;
• if required, water is introduced, not more than 200 ml;
• then kneading continues for 2-3 minutes until a solution with a homogeneous consistency is produced;
• if it is impossible to provide proper moisture care for concrete, it is recommended to introduce moisture-retaining additives. The amount is taken as 0.25 kg for every 100 kg of dry mix;
• if it is required to prepare a small amount of mortar, it is permissible to knead with a construction drill with a paddle nozzle. Thixotropic mixtures are not mixed by hand.

Preparation of flowable cement mortars:

• the working composition is prepared in a concrete mixer. Pour the required amount of water into the bowl of the equipment. To ensure medium fluidity, 3.6-3.7 liters of liquid per 25 kg of dry powder will be required, for highly fluid - take 3.8-4.0 liters per 25 kg;
• After adding water, the stirrer is started, the dry powder is continuously introduced. The kneading lasts 1-2 minutes;
• the finished mixture should be liquid, without lumps;
• It is permissible to use an electric drill with a nozzle. The composition is kneaded by hand in exceptional cases, prepared in small portions for 5-6 minutes.

Dry mixes for the repair of concrete affected by corrosion of reinforcement, fast curing compositions are prepared in an identical way

Preparation of injection solution:

• 6-6.4 l of water is poured into the concrete mixer and 20 kg of dry mix is ​​introduced. The solution is mixed for several minutes until a homogeneous fluid mass without lumps is formed.

Preparation of elastic waterproofing:

• liquid component B is poured into a clean container;
• component A is slowly poured and the mixture is kneaded with a construction low-speed mixer;
• the kneading lasts several minutes. Control the thoroughness of mixing at the bottom and walls of the container;
• waterproofing can be prepared in a concrete mixer equipped with mortar sprayers. With this method, you should make sure that the mixture is homogeneous and without lumps. So it will calmly pour into the sediment funnel.

If it is necessary to prepare a rigid waterproofing, water is added to a clean container, a dry mixture is introduced in portions. The composition is mixed with a low-speed mixer for 2-3 minutes. The material must stand for 10 minutes, after which it is re-mixed and goes to work.

Application of solutions

Repair of concrete structures can be carried out using special equipment or hand tools.

Application of thixotropic mortar:

• thixotropic mixtures are applied to vertical or horizontal structures by hand using a trowel or spatula. It is possible to involve a mechanized method with the help of special equipment (shotcrete installations);
• the allowable thickness of one layer is taken as 35 mm. The layer-by-layer exposure time should be 4 hours;
• before applying the material, the reinforcement must be cleaned and coated with an anti-corrosion compound;
• the temperature of the base during the repair should not be lower than +5 degrees. In case of rain and strong wind, the composition is not applied;
• average consumption - 19 kg of dry powder per m2 of surface when developing a layer of 1 cm;
• during the day, the repaired area is moistened.

Application of fluid solution:

• the finished solution is continuously poured into the formwork, the concrete is pre-impregnated with water. Formwork before starting work is treated with appropriate materials (lubricants) to prevent the absorption of water contained in the solution;
• in the process of pouring do not use vibrolaths, vibrators, etc.;
• the material must fill the entire volume of the formwork. If there are hard-to-reach places, the solution is applied there manually;
• in hot weather, cold water is used to prepare the mixture, the filling is protected from solar radiation. Average consumption - 20 kg / m2 per 1 cm layer.

The use of mortars with a rapid set of strength:

• the prepared material is poured onto the prepared surface without the use of vibration;
• the composition is evenly distributed over the entire area of ​​\u200b\u200bthe repaired area with the help of a trowel, spatula, trowel. Smoothing is carried out immediately after leveling.

The internal parts of the formwork are treated with grease for subsequent easy dismantling

If the solution is poured into the formwork, it is continuously fed from the selected side (it must be one). This will help prevent air entrapment. Surface care is required within 24 hours.

Application of injection solution:

• make sure that the base is structurally resistant to injection pressure. Otherwise, it is required to strengthen the concrete;
• the solution is introduced under a pressure of 1-2 atm, through pre-installed packers (tubes);
• work begins with the lower packer, gradually moving up until all defects are filled. Typical consumption is 1.6 kg to fill a cavity with a volume of 1 liter.

Application of elastic waterproofing:

• after preparation, the solution must be applied within 1 hour;
• if manual application is intended, spread the material with a smooth spatula. The second layer is applied on top of the fresh first layer. The thickness of the two-layer system should not exceed 2 mm;
• with a large amount of work, the composition is applied by spraying;
• if it is required to waterproof critical structures (intensive loads), a fiberglass reinforcing mesh is pressed into the fresh layer. After that, the surface is leveled and after 4-5 hours a second layer is applied.

Rigid waterproofing is applied by spraying, brushing or spatula. If a brush is used, 2-3 layers are implemented in compliance with layer-by-layer drying (5-6 hours). When using a spatula, it is still recommended to apply the first layer with a brush.

When spraying, the waterproofing is applied in two layers, after waiting for the partial hardening of the first. The final thickness of the coating should be 2-3 mm. In windy and hot weather, the base is protected from the rapid evaporation of moisture with a polyethylene film.

Reinforcement corrosion protection

Reinforcement bars must be cleaned of corrosion. In the course of the work, the possibility of applying an anti-corrosion compound to the rear side of the reinforcement is evaluated. When preparing a working solution, the amount of water used is controlled. The thickness of the applied layer is measured with a caliper (before and after application).

When the reinforcement is processed, a solution with anti-corrosion properties is applied. Application on vertical surfaces is carried out manually using a spatula or trowel. The maximum layer thickness is 35 mm. Mechanized technology with the help of special equipment is acceptable. The exposure time of each layer is 4 hours.

Repair of concrete floor screed

To restore such bases, thixotropic solutions are successfully used. With their help, you can eliminate minor defects, large cracks, and carry out major repairs. The principles of surface preparation and solution preparation remain typical. Before repairing defects or pouring a new screed with a thixotropic mixture, priming is carried out.

Quality control

After the repair and restoration work is completed, quality control is carried out, for which special equipment and visual inspection are used. Most often, structures are checked by mechanical means: adhesion meters, sclerometers, hammers, devices that determine the quality of the floor screed.

After measurements, the obtained characteristics are compared with regulatory documents

Safety precautions when repairing concrete on the street

Persons of full age (18+) are allowed to carry out the work. All workers must undergo appropriate instruction, medical examination and training. Provision of personal protective equipment is required. Repair compounds may cause irritation on contact with skin and mucous membranes. If such contact occurs, the affected area is abundantly cleansed with water and medical attention is sought.

The cost of work

The average financial costs for the restoration of structures for various purposes start from 2.5 tr. per cubic meter. This price includes preliminary preparation of the bases, the main stage of work and maintenance.

findings

The choice of material for the repair of artificial stone should have an integrated approach. The use of a particular technology depends on the operational characteristics of the bases, the condition of the concrete, and the degree of its damage.

Modern cement mixes, with which the market is so filled, are considered a universal solution for the repair and restoration of concrete structures. Thixotropic compositions have successfully proven themselves in restoring the bearing capacity of even the most critical objects.

Flowable, anchoring and fast-setting mortars are used in any repair practice for leveling and sealing damage on concrete that is not subject to high loads.

An example of repairing concrete structures on the street is shown in the video:

Repair mixtures are designed to eliminate various defects in concrete structures. Special compositions can be used in winter and summer, they tolerate temperature extremes well, let water vapor through, are not afraid of mold and fungus, have increased adhesion, and provide a quick and durable connection.

The widespread use of concrete is due to a large set of advantages: strength, incombustibility, durability and low cost. Gradually, under the influence of various factors, the structures begin to collapse. The reasons are different: non-observance of proportions during mixing, violation of the mortar laying technology, mechanical damage, aggressive external environment. As a result, the material loses its design characteristics, cracks and chips are formed.

Additional concreting usually does not give good results, so it is better to purchase specialized mixtures for repairs. They help to quickly restore the geometric parameters and performance.

Situations in which it is advisable to use them:

• multiple chips in the floor;
• recesses exposing the reinforcing cage;
• cracks with a width of more than 0.5 mm;
• significant dust formation;
• base corrosion (deep or surface);
• other defects larger than 0.3 mm.

Types and characteristics of mixtures

In the distribution network they are sold in the form of dry powders, which are enough to be diluted with water in certain proportions. Ready mortar fills the free space in concrete, reliably seals and strengthens the defective surface. To impart special qualities (frost resistance, moisture resistance, high hardening rate), various plasticizers, modifying additives, and granular aggregates are used.

All of them are conditionally classified according to several criteria.

1. By the complexity of the composition.

• One-component - cement with different fineness of the filler.
• Two-component - epoxy of varying degrees of fluidity.
• Multicomponent - polyurethane liquid.

2. According to the degree of compression.

• Shrinkage - mixtures that shrink when cured in air. When shrinking, it is difficult to calculate in advance the required number of layers. Depending on the complexity of the repair, it is additionally applied 1-2 times. The main advantage is the low price.
• Non-shrinking - includes special additives with an expanding reagent. This allows you to get a non-separating and mobile solution that does not shrink and quickly hardens. With it, you can easily repair any base, which in the end is strong and durable. Of the shortcomings, only the high price.

3. By appointment.

• Compositions for concrete structures subjected to increased mechanical loads: load-bearing walls, floor slabs, beams, columns.
• Mixtures for strengthening reinforced concrete elements against corrosion, as well as protection against fungus and mold.
• Means of increased strength for road surfaces and screeds. In winter, they provide additional protection from frost.

4. According to the conditions of use.

• Molded - for screeds and other horizontal planes.
• Thixotropic - to correct defects on the walls.
• Frost-resistant - for concrete surfaces on the street.
• Fast-hardening - for urgent repairs and elimination of leaks.
• Industrial and domestic purposes.

With the help of bulk (injection) types, planes up to 100 mm thick can be repaired. Fast-hardening compounds are used for a working layer of not more than 40 mm.

How to choose mixes for concrete?

When buying, you need to proceed from the nature of the defect, the size of the damaged area and the operating conditions. It is better to choose solutions that, after setting, do not exfoliate and do not shrink.

Of great importance is the compatibility of the composition with the work surface and the level of adhesion. Large manufacturers in the product line always have branded deep penetration soil mixtures that bind concrete and provide reliable adhesion.

When choosing, you need to take into account the scale of the repair. Deep cracks, potholes and pronounced drops are leveled with coarse-grained mortars or reinforced with fiberglass. For small chips and cracks, it is better to buy a version of increased plasticity with a content of small fractions.

If the concrete is used outdoors, in damp and other extreme conditions, then the compositions must contain additives that give special characteristics (frost resistance, water resistance, etc.). Properly selected products and strict adherence to the instructions for use are a guarantee of strength and durability.

Repair Technology

To correct large defects and level differences, inexpensive sand-cement mixtures are most often used.

• Clean the work surface from dust and debris and degrease.
• For better adhesion, treat the concrete with an epoxy primer.
• Estimate the scale of the repair and make a calculation of the required composition. Experts recommend maintaining the thickness of the screed within 40 mm.
• Set control beacons and lay the solution.
• Remove excess and level with a rail.
• Cover the finished plane with plastic wrap and leave for 2 weeks to gain strength. During this time, the concrete is periodically (more often in summer) moistened with water to avoid cracking.

If the size of the defects is insignificant, then for horizontal planes it is better to buy self-leveling bulk types with increased plasticity.

2. Crack repair.

First, all slots are widened and cleaned. To do this, you need to cut grooves around them to a depth of not more than 50 mm. It is convenient to do this with a diamond wheel or a grinder. Then select the debris with a chisel or perforator. Clean the working area with compressed air or with a vacuum cleaner, prime and apply the product.

• Gradually fill cracks on horizontal and inclined surfaces with mortar, without exerting strong pressure on it.
• To eliminate cracks on vertical planes, dry mixes of fast hardening should be used.
• Internal voids and very deep cracks are filled by injection, using a special device for this - a packer. Remove excess compound acting under pressure with a rail.

After hardening, the surface is polished.

Overview of popular brands

The manufacturer is the Russian company Basf. Mixtures are used to repair defects of varying degrees of complexity.

• Emaco N 5100 is chosen for minor damage: cracks, shells, dust formation.
• Emaco N 900 and N 5200 are recommended for defects of moderate severity: small chips, crumbled areas.
• Emaco S 5400, S 488 are designed to eliminate the consequences of corrosion, remove cracks up to 40 mm deep.
• Emako T 1100 TIX, S 466, S 560FR, A 640 - for heavily damaged structures with open reinforcement and deep chips.

2. Consolidation Bars.

The Russian-made composition is excellent for restoring vertical and horizontal surfaces. It sets quickly and does not shrink. Possesses high degree of adhesion with concrete.

• Bulk - for horizontal and inclined planes.
• Thixtotropic - for the restoration of walls and various vertical surfaces. The line is represented by repair, finishing, reinforcing and moisture resistant coatings.

A product of domestic production, intended for the reconstruction of concrete of any complexity.

• Birss 28,29,30,30N - for light repairs of cracks and crumbled surfaces.
• 30S1, 58S1, 59S2 - for the restoration of structures of an average degree of deterioration.
• 59С3, 59Ц - options for serious damage.
• RSM, RBM, 600VRS are used in cases of severe damage.

4. Knauf Flahendicht.

Specially designed for repairing concrete defects. Gives the planes steam and water resistance. Among the many positive characteristics are the absence of toxic components and small volumes of packages (5-6 kg). Equally used outdoors and indoors.

5. Ceresite CX5.

Restoring mix for repair of concrete products in the conditions of the increased humidity. It does not shrink during hardening and reliably protects against high and low temperatures.

6. Founding.

• Innoline NC60 is a grout used for the restoration of all types of surfaces. It is successfully applied to installation and fixing of the heavy equipment on the concrete basis.
• Selform T112 - for walls and floors. Features excellent grip and water repellency.

Price

Potholes, chips, cracks - all this can happen to any concrete surface. In this article we will tell you how and with what mixtures you can repair concrete.

Types of repair compounds

Concrete is known for its strength, reliability and durability. However, under the influence of various factors over time, it begins to collapse. The reason for this may be poor-quality installation, non-compliance with the proportions of the components, aggressive external environment, mechanical damage. Defects can be eliminated with the help of special repair compounds.

In order to prepare the composition, you need to mix the dry repair mixture with water. A variant is possible with the use of special additives that improve some of the characteristics of concrete. Ready-made compounds are used to repair floors, walls, stairs, bridges, roads and other concrete structures.

All repair mixtures can be conditionally divided according to their purpose:

• for the repair of load-bearing concrete structures, for example, columns, beams, floor slabs;
• for the repair of roads and concrete floors;
• to protect concrete structures from corrosion.

A fairly wide range of repair compounds with different properties is presented on the market, from various domestic and global manufacturers. Accordingly, their quality and price category can vary quite significantly.

Repair compounds must provide high adhesion to concrete, non-shrinkage and absolute compatibility with it. With their help, the bearing capacity of structures is restored, water resistance, frost resistance and concrete strength are increased. In addition, they must be affordable and economically viable.

According to international and domestic experience, it has been proven that the use of repair mixtures is more effective than the use of traditional cement-sand mortars.

Repair mixes for concrete are divided into thixotropic and casting mixes. The former are used for vertical surfaces, the latter for horizontal ones. You can increase the reinforcing properties with the help of fiberglass.

How to choose a repair compound

Several factors influence the choice of repair composition:

• damage type
• defect size
• terms of Use

There are three main types of repairs:

• reinforcement of the concrete surface
• leveling the concrete surface
• crack repair

To strengthen concrete, which carries heavy loads and has a fragile surface (screed, floor slabs), deep penetration primers are usually used.

The most common type of concrete repair is leveling unevenness. The sealing of vertical surfaces is carried out using thixotropic dry mixes. They perfectly cling to the surface, hold well on them and do not blur. They have minimal shrinkage and high characteristics in terms of strength, water and frost resistance.

Particularly critical areas require the addition of reinforced fiberglass. Quick repair is provided by special compounds. Their curing time is up to 6 hours. But they have a limitation on the thickness of the layer - up to 30-40 mm.

Horizontal surfaces are leveled with casting mixtures. They are more liquid and, due to this, they are simply poured onto the surface. The mixture sets quickly, has minimal shrinkage and is quite strong. One layer can be laid up to 10 cm thick.

Leveling compounds are also used to repair cracks in concrete.

The choice of repair composition is influenced by the operating conditions of the structure. If necessary, components can be added to the mixture that enhance various properties, for example, water resistance or quick solidification.

The most famous manufacturers of repair mixtures are BASF, MAPEI, SIKA, from Russian ones - Lakhta, Alit, Konsolit, SpetsRemSmes.

floor leveling

To level the floor, it is necessary to prepare a cement-sand screed. The concrete surface is pre-cleaned of dust and treated with a primer. After that, they are determined with the point at which the floor will be leveled, beacons are installed at the laser level.

Next, the screed is poured. Its maximum height should not exceed 35-40 mm. The pre-mixed solution is poured onto the surface and leveled with a spatula. On the second day, the beacons are removed and the seams are sealed with a rubbing solution.

The screed should dry well. This may take up to 2 weeks. The screed is covered with a film, and the surface itself is periodically moistened with water. Thanks to this, it will become stronger and will not crack.

Horizontal surfaces can be repaired using a self-levelling compound. They are used in the presence of small defects and uneven areas. The end result is a perfectly flat surface.

To level the floor, I use the following mixtures: VOLMA-Nivelir Express (cost - 14 rubles / kg), Vetonit-2000 (17 rubles / kg), KESTONIT 97 (39 rubles / kg).

Floor pothole repair

At the beginning of work, small incisions are made around the damage using a diamond disc or grinder. Then, the remains of damaged concrete are removed with a chisel and a perforator, the surface is cleaned of dust. For better adhesion of the composition to concrete, a special epoxy primer is applied to the surface.

After applying the solution, it is necessary to remove its excess and level the surface with a rail. After complete drying, the composition becomes as durable as possible. The closed place is polished.

The following mixtures are suitable for filling potholes: IVSIL EXPRESS-BASIS (cost - 10 rubles / kg), Thomsit RS 88 (30 rubles / kg), LAKHTA Quick Repair (80 rubles / kg).

Crack repair

Cracks appear in concrete due to various reasons. Over time, they can grow, destroying the whole structure. This defect must be repaired.

Vertical cracks are repaired by the injection method. When using the injection method, the composition is pumped into the fracture using special equipment - a packer.

Surface cracks, which usually form on inclined and horizontal surfaces, are repaired by the saturation method. In this case, the cracks are impregnated with a mixture without pressure.

There is another way to fix cracks. At the beginning of the work, the crack is sawn 25-50 mm deep and 10-20 mm wide. Excess concrete must be removed and the crack blown out of dust and dirt. The cut is filled with a repair mixture. In the event that the concrete crumbles, it is worth using a better mixture, if it practically does not dust, a cheaper agent will do.

The following mixtures can be used to repair cracks: LAKHTA basic repair compound (cost - 57 rubles / kg), BASF MasterEmaco S 488 (33 rubles / kg), Sika Monotop 612 (86 rubles / kg).

Comparative table of technical characteristics of dry repair mortars:

The main technical characteristics presented in this table will help you choose the best repair mortar for your needs.

The right mixture for concrete repair and the quality of the work performed guarantee an excellent end result.

Andrey Badovsky, rmnt.ru

Concrete is considered a very strong, reliable and durable material. However, under the influence of various influences, it begins to collapse. Sometimes defects occur after a short time, and they can be eliminated with special repair compounds.

Concrete is strong enough, strong and durable material, however, it is not eternal. Cracks and breaks may appear on it. And in such cases, it is necessary to use special mixtures to repair it.

Repair compositions for concrete are special products, which include cements, fillers, sand and various additives that give certain properties to the solution.

Scheme of repair of concrete defects with reinforcement exposure: a - concrete defect with reinforcement exposure; b - removal of destroyed concrete, application of a protective layer on the reinforcement; c - restored section of the structure 1 - building structure; 2 - fittings; 3 – “KTtron-primer” material; 4 - repair material "KTtron" thixotropic (depending on the project).

Dry repair compounds are completely ready for use after mixing with water. They are used to eliminate imperfections in concrete floors, walls, bridges, stairs, roads and other concrete structures.

Dry repair compounds are intended for:

• repair of load-bearing structures (beams, columns, floor slabs, etc.);
• repair of road surfaces (runways, parking lots, etc.), industrial floors, floors in warehouses, etc.;
• protection of concrete and reinforced concrete surfaces against corrosion.

Currently, repair compounds for concrete are presented in the widest range: from various manufacturers, with different properties and different price categories. Means for removing defects are divided into two main groups: thixotropic (for vertical surfaces) and casting (for horizontal planes). To increase the reinforcing properties, fiber can be added to the composition of the mixture.

The choice of mix for concrete repair

Scheme for repairing a panel made of cellular concrete with a destruction depth of 20 to 50 mm and an area of ​​up to 0.5 m2: 1 - panel; 2 - nails; 3 - metal wire; 4 - destruction contour.

The choice of mixtures for depends on several parameters: on the type of damage, surface defect, as well as on operating conditions.

Strengthening the concrete surface. Often, concrete surfaces that carry heavy loads have a fragile surface (floor slabs, screed and other monolithic structures). In such cases, deep penetration primers for concrete should be used.

Surface leveling. Rough surfaces are one of the most common defects in concrete structures. In this case, deep penetrating primers are also excellent. For vertical surfaces, thixotropic dry mixes should be used, they fit well on the surface, do not blur and adhere well to vertical planes. In addition, they have high strength, frost and water resistance and have minimal shrinkage.

When repairing particularly critical areas, it is necessary to use reinforced fiberglass. There are also special compositions for quick repairs, which harden in the shortest possible time. In this case, the thickness of each layer should not exceed 35 mm.

Bare reinforcement in concrete structures must be treated with an anti-corrosion primer.

For leveling horizontal surfaces, casting dry mixes are used. Such compounds have a more liquid consistency, unlike thixotropic ones, and are poured onto the surface. The thickness of one layer can reach 10 cm. The mixture has minimal shrinkage, high coating strength and fast setting.

Crack repair. Another common defect in concrete surfaces is cracks. To repair cracks, as a rule, the same compositions are used as for leveling the surface.

When choosing a composition for concrete repair, it is worth considering the operating conditions. During production, various components can be added to the mixture, giving certain properties, for example, frost resistance, water resistance, rapid solidification of the composition, and so on.

floor leveling technology

Alignment of horizontal surfaces can be done independently. Although the work is quite laborious and requires knowledge of technology, but, following all the rules, you can get a perfectly flat plane with your own hands.

To level the floor, a cement-sand screed is required. Before starting work, the surface must be cleaned of dirt and dust, the old coating. Then the plane is treated with a primer, which contributes to a more uniform spreading of the solution.

Next, you should determine the highest point, according to which the floor will be leveled. After that, beacons are installed, which can be used as metal corners, profiles or pipes. Beacons are installed in such a way that their height is at the same level. To do this, it is better to use a laser level.

Schemes of sealing expansion joints of concrete dams: a - diaphragms made of metal, rubber and plastics; b - dowels and gaskets made of asphalt materials; c - injection seals; g - bars and slabs of concrete and reinforced concrete; 1 - metal sheets; 2 - profiled rubber; 3 - asphalt mastic; 4 - reinforced concrete slab; 5 - wells for grouting; 6 - grouting valves; 7 - reinforced concrete beam; 8 - asphalt waterproofing pad.

After installing the beacons, the pouring of the screed begins. The layer thickness should not exceed 40 mm. The solution, previously mixed in a plastic or metal container, is poured onto the base, then leveled with a spatula.

After pouring, the screed must dry out, this may take up to two weeks. On the second day after pouring, it is necessary to remove the beacons, and seal the seams with a grouting solution.

When drying, the screed must be covered with plastic wrap. Periodically, it is recommended to moisten the surface with water. This will prevent cracking of the surface and give the screed greater strength.

It is also possible to repair horizontal concrete surfaces with the help of a self-leveling mixture. Such compounds are used in cases where the surface has small defects, uneven areas up to 3 mm. The result is a perfectly flat surface.

Pothole Removal

Scheme of repairing a chipped edge of the concrete coating at the seam: a - before repair; b - after repair; 1 - existing concrete; 2 - edge chip and crack in concrete; 3 - gravel; 4 - dirt; 5 - expansion joint; 6 - waterproofing; 7 - freshly laid concrete; 8 - polyethylene film; 9 - mortgage board.

Often, defects such as potholes appear on the concrete surface. They are eliminated as follows. First, an incision is made along the perimeter of the damage, the depth of which should not exceed 2 cm. For this, it is better to use a tool such as a grinder with a diamond disc. After the incision is made, the remains of the concrete are removed using a perforator and a chisel.

Next, remove dust and dirt. For the best removal of all debris, a vacuum cleaner or sandblasting equipment should be used. An epoxy primer is applied to the cleaned surface. It provides better adhesion of the composition with. Then the pothole is filled with a special compound for repairing the concrete surface.

Excess mortar is removed, and the surface is leveled with a rule or rail. After that, the patch is kept for the required time until it dries completely. During this time, the composition acquires its maximum strength. The final stage is grinding the repaired damage.

For repairs, special dry mixes should be used, and not a regular concrete mortar, since the repair compounds have special properties that ensure the strength of the coating.

Repair of cracks in concrete

They may appear due to various reasons. At the same time, they can develop further, which negatively affects the strength of the whole structure, or not spread further. In any case, the defect must be repaired.

Depending on the width of the crack and the material used to seal the crack, there are various ways to eliminate defects:

• injection. Vertical cracks are always eliminated in this way. For injection, special equipment is used - an injection packer, with the help of which, under pressure, the crack is filled with a repair compound;
• saturation. The method of saturation (impregnation) is used to eliminate surface cracks. As a rule, such defects occur on horizontal or inclined surfaces. When impregnating cracks, the repair compound is injected into the crack without pressure.

Cracks can be eliminated in the following way. First, the crack is sawn to a depth of approximately 20-50 mm (depending on the size of the crack) and a width of 10-20 mm. After that, excess concrete is removed, dust and dirt are blown out. Then the cleaned cut is filled with a repair compound. At the same time, it is worth considering that if the concrete does not particularly dust during operation, then the composition can be used cheaper, simpler. If the concrete crumbles, then you should choose a better and more expensive product.