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, it begins to deteriorate over time. The reason for this may be poor-quality installation, non-compliance with the proportions of the components, an aggressive external environment, or mechanical damage. Defects can be eliminated using special repair compounds.

In order to prepare the composition, you need to mix the dry repair mixture with water. It is possible to use 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 roughly divided according to their purpose:

· for repair of load-bearing concrete structures, for example, columns, beams, floor slabs;

· for road repairs and concrete floors;

· to protect concrete structures from corrosion.

There are quite a few on the market wide range repair compounds with different properties, from different domestic and global manufacturers. Accordingly, their quality and price category may differ quite significantly.

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

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 mixtures for concrete are divided into thixotropic and castable. The first are used for vertical surfaces, the second - for horizontal. The reinforcing properties can be increased using fiberglass.

How to choose a repair compound

Several factors influence the choice of repair composition:

type of damage

· defect size

· terms of Use

There are three main types repair work:

· strengthening the concrete surface

· leveling the concrete surface

repair of cracks

To strengthen concrete that carries heavy loads and has an unstable surface (screed, floor slabs), primers are usually used deep penetration.

The most common type of concrete repair is leveling out uneven surfaces. Sealing of vertical surfaces is carried out using thixotropic dry mixtures. They cling perfectly to the surface, stick well to them and do not blur. They have minimal shrinkage and high strength, water and frost resistance characteristics.

Particularly critical areas require the addition of reinforced fiber fiber. Quick repairs are ensured by special compounds. Their hardening time is up to 6 hours. But they have a limitation on layer thickness - up to 30–40 mm.

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

Leveling mixtures are also used to repair cracks in concrete.

The choice of repair composition is influenced by the operating conditions of the structure. If necessary, you can add components to the mixture that enhance different properties, for example, water resistance or fast hardening.

The most famous manufacturers repair mixtures - BASF, MAPEI, SIKA, from Russian ones - “Lakhta”, “Alit”, “Consolit”, “SpetsRemSmes”.

Leveling the floor

To level the floor, you need to prepare a cement-sand screed. The concrete surface is first cleaned of dust and treated with a primer. After this, they determine the point at which the floor will be leveled, according to laser level beacons are installed.

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 trowel.

The screed should dry well. This may take up to 2 weeks. The screed is covered with 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-leveling compound. They are used in the presence of small defects and uneven areas. The result of use 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).

Repairing potholes on the floor

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

After applying the solution, it is necessary to remove its excess and use a lath to level the surface. After complete drying, the composition becomes as durable as possible. The sealed area is sanded.

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

Due to various reasons Cracks appear in the concrete. Over time, they can increase, destroying the entire structure. This defect must be repaired.

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

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

There is another method for eliminating cracks. At the beginning of work, the crack is sawn 25–50 mm deep and 10–20 mm wide. Excess concrete must be removed and the crack must be blown out of dust and dirt. The cut is filled with repair mixture. If the concrete crumbles, it is worth using a higher quality mixture; if it produces virtually no dust, a cheaper product will do.

To repair cracks, you can use the following mixtures: “LAKHTA basic repair composition” (cost - 57 rub./kg), BASF MasterEmaco S 488 (33 rub./kg), Sika Monotop 612 (86 rub./kg).

Comparative table of technical characteristics of dry repair mixtures:

Options	"LAKHTA basic repair composition"	BASF MasterEmaco S 488	Sika Monotop 612
Material consumption, kg/dm 3	1,6–1,7		2,11
Water consumption, l/kg	0,13	0,145–1,6	0,1–0,115
Strength of adhesion to concrete after 28 days, MPa, not less			1,5–2,5
Bending strength after 28 days, MPa, not less			7–9
Waterproof grade no less
Application temperature, °C	from +5 to +35	from +5 to +50	from +5 to +35
Cost, rub./kg

Basic technical specifications presented in this table will help you choose best option repair mixture for your needs.

The right mixture for concrete repair and quality work guarantee an excellent final result.

Andrey Badovsky, rmnt.ru

http://www. rmnt. ru/ - RMNT website. ru

The choice must be approached as responsibly as possible. After all, if work to restore a concrete base is carried out using unsuitable or low-quality materials, the structure only loses strength, not to mention the fact that its cost increases significantly.

What causes concrete to fail?

Concrete structures are destroyed under the influence of the following negative factors:

Chemical reactions caused by increased carbon content in concrete. These processes provoke a violation of the proportions of water and cement content in the solution.

Chemical reactions caused by the action of chlorine ions contained in road salt, which is used in the cold season to protect reinforced concrete road surfaces from ice. As a result of these processes, oxidation of reinforcement in concrete begins.

Action of moisture. Water seeps into concrete cavities. When frozen, it crystallizes and causes destruction and cracking in the concrete structure.

Mechanical factors - shocks and dynamic impacts exceeding the permissible loads provided for in the design documentation, etc.

Seismic processes.

Natural disasters - floods, hurricanes, etc.

Fires.

Failure to comply with technological standards and violations at the construction stage. For example, long periods of downtime during the concreting stage can lead to poor adhesion of the new concrete to the old base. This entails the formation of working (cold) seams and, over time, reduces strength and damages the aesthetics of the structure.

The main stages of concrete repair activities

Work is carried out in the following sequence:

Examination. At this stage, specialists assess the severity of the damage caused and analyze possible reasons who provoked them. To do this, the size of cracks, the thickness of the protective layer, the intensity of carbonization processes, etc. are measured. Based on the results of the surveys and their recommendations, a repair plan is drawn up and the means intended for this are selected.

Preparatory work. The damaged layer and signs of previously carried out restoration measures are completely removed from the base to a dense, clean and solid base. Its surface is cleaned of all types of dirt, traces of paint, oils, etc.

Processing of reinforcement. Bare reinforcement bars are carefully cleaned from traces of corrosion and covered with protective compounds.

Repair work. Construction mixtures for concrete repair are applied manually, by pouring (for example, into formwork) or by spraying/gunning.

- Recovery using special means. Protective compounds on an organic or inorganic basis protect concrete from negative effects environment, pollution and other aggressive external factors.

If necessary, a decorative layer is applied over the protective layer.

Types of mixtures for concrete repair

Depending on the purpose and nature of use, the following types of compositions are distinguished:

Compositions used to restore load-bearing concrete structures (floors, beams, highways, floors in industrial premises and other types of coatings experiencing strong dynamic loads).

Compounds used for non-structural restoration of concrete, leveling the surface of the base and sealing minor defects.

When choosing a repair composition for concrete, the nature and extent of damage, the specific operating conditions, technical parameters of concrete and other factors are taken into account.

Concrete repair mixtures from MAPEI

MAPEI offers various materials for a complete and quality repairs reinforced concrete structures:

• Means for anti-corrosion protection of fittings.
• Materials for repair of reinforced and unreinforced concrete.
• Leveling mixtures.
• Waterproofing compounds.
• Epoxy resins for crack repair injection method.
• Finishing decorative and protective materials, etc.

The most popular materials for complex concrete repair from MAPEI are produced in Russia, at the company’s own factories.

The most popular mixtures for concrete repair from MAPEI

Mapegrout Thixotropic is a dry mixture for the repair of reinforced concrete and concrete structures, reinforced with polymer fiber, with compensated shrinkage. It is characterized by excellent adhesion to concrete and steel, frost resistance, water resistance, and mechanical strength. Applied in a layer of 10 to 35 mm. Thanks to its thixotropic properties, it is suitable for use on both vertical and horizontal bases, without requiring the use of stationary formwork. Gains strength quickly. This dry mixture is intended for surface restoration concrete foundations- for example, for filling formwork marks, smoothing open reinforcing rods, repairing upper layers industrial floors, ramps, etc.

Mapegrout Hi-Flow is a dry mixture for repairing concrete by pouring into formwork. Indispensable where, due to the depth and specificity of the damage, materials with high fluidity rates are required - for example, for restoring road surfaces, filling the distances between elements of concrete structures, etc. Apply in a layer of 10 to 40 mm. Upon contact with water, it forms a concrete mixture that is not subject to delamination, resistant to abrasion, and low temperatures and having waterproofing properties.

Mapegrout 430 is a concrete repair material characterized by controlled shrinkage and medium strength values. Used for repairing concrete foundations destroyed as a result of corrosion processes in reinforcement. It is applied in a layer of 5 to 35 mm without the use of formwork on vertical surfaces. In order to ensure the composition can fully expand on open construction sites, it is recommended to use it in combination with the Mapecure SRA additive.

Mapegrout SV-R Fiber is a dry repair mixture that quickly gains strength and is intended for the repair of serious defects where the coating is subject to heavy loads and long-term downtime is not possible (road surfaces, airport runways, industrial premises etc.). Can be used under negative temperature conditions from -5*C. Apply a layer of 20-50 mm.

ARB-10 and ARB-10F are concrete repair compounds that quickly gain strength. They are characterized by high resistance to mechanical damage, water resistance and compensated shrinkage. Thanks to the presence of steel fibers in the composition, ARB 10F can be used to repair foundations subject to severe loads. These products were developed specifically for the restoration of airport runways, bridges, industrial floors, etc. Apply in layers from 50 to 300 mm

Mapefill and Mapefill 10 are expansive, flowable concrete mixtures that do not shrink and quickly gain strength. Used for base fixing and anchoring industrial equipment. In addition, it is suitable for filling seams, technological cavities, etc.

Stabilcem is a cement binder for the preparation of injection solutions for repairing cracks in concrete, brick, and stone using the injection method. It is also used to compact foundations and fill hard joints.

Compositions:

Mapelastic is an elastic composition for protection against water load and atmospheric influences, both external (balconies, terraces) and underground parts of the structure (basement walls, swimming pools, water tanks, etc.), as well as plastered surfaces and old floors.

Idrosilex Pronto - rigid waterproofing for the protection of underground structures: basements, foundations, channels, swimming pools, under positive and negative water pressure

We focused only on the most famous repair compounds from MAPEI. The company’s product range is so wide and includes so many materials for different areas of construction that it is simply impossible to list the entire product line in one article.

Comments:

Repairing cracks in concrete sometimes appears as a task of increased importance. Defects and cracks form both in old structures and in newly built ones. Before you start getting rid of cracks, you will need to choose the most convenient method.

Cracks in concrete can occur due to moisture or deformation of the concrete product, shrinkage or stress.

Sealing cracks in concrete

Defects and cracks can form both in new concrete structures and in those that have been in use for some time. The reasons for their appearance can be very different. If you do not eliminate them, but only carry out minor repairs, the structure will gradually collapse.

Cracks can be, for example, deformation or shrinkage. Deformation cracks are those that occur due to temperature expansions or incorrect shrinkage. They can appear in structures with light loads that are not load-bearing. These can be screeds, the bases of paths and porches, etc. Their opening is most often small and amounts to a few mm, so they do not affect the strength of the structure. They can decrease or increase due to changes in humidity, air temperature, shrinkage of foundations and soils.

Shrinkage cracks can be caused by the concrete mixture setting and drying too quickly. The opening of cracks may be uneven, but not large. Sometimes concrete becomes covered with a web of small cracks that are barely noticeable to the eye. But if you wet the surface, the cracks immediately become clearly visible. They do not pose a threat to the strength of concrete, but through them the structure will be saturated with moisture.

Reasons for the formation of cracks in a concrete structure:

Repair of cracks is carried out by filling the depth with synthetic solutions with the addition of resins.

1. Seating. For example, a foundation made of concrete may settle due to the fact that the soil compresses unevenly, and the load is different for different areas. A material such as concrete is not so strong that it does not change under loads, and during its hardening it can crack due to uneven loads.
2. Corrosion. Exposure of components to carbon dioxide, carbonation, and salts creates the most favorable environment for cracks to appear in the material.
3. Mechanical loads. Various types of destruction can occur due to accidents, possible seismic activity, excessive vibrations, and so on.
4. Other impacts. The material may slowly deteriorate due to the influence of salts, acids or alkalis.

Here are the main reasons why defects may occur in the material. Any problems of this kind require immediate elimination, otherwise cracks in concrete will appear again and again.

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How to repair defects in concrete

When starting to repair cracks, first determine how you will do it. In most cases, thin cracks in concrete are simply primed, plastered, or painted on top.

If unstable cracks appear in unloaded structures, they can be sealed with silicone or other elastic sealants.

Cracks are sealed mainly by filling the depths with synthetic mixtures with the addition of resins, which have low viscosity. Holes are drilled along the crack; they must be placed diagonally, towards the defect. After this, bushings are placed in the holes and the working mixture is pumped through them. Then the resin is pressed in using an injector. This method helps ensure the structure has good strength and is able to function as a single unit.

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Sealing and injection of concrete

One of the methods most often used to eliminate defects is called sealing, the second is injection. He is considered the most professional and possessing best effect. But to use it you need to have certain working skills. This method is more expensive, but the results are impressive. The procedure is carried out as follows: special compounds made of polymers or cement mixtures with additives. They are able to quickly fill the space, after which they harden.

Another method is called crack sealing. First, the cavity should be cleaned of crumbling concrete particles. Then tap the space with a chisel. The excess layer of concrete must be removed 300 mm up from the crack and the same amount down. After treatment, crumbs and dust are completely removed from the area and the prepared repair compound is applied. It is prepared from a solution of sand and cement, adding polymer components. You can use epoxy resin in this composition. At the last stage, the treated surface is coated with polyurethane sealant.

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Which repair compounds are more popular?

Preparation of the composition from epoxy resin, quartz sand and hardener.

If, when examining the surface where work is to be carried out, it was decided to remove a layer of concrete with defects, a new layer of cement-sand mixture will then need to be applied in its place. To do this, you need to carefully consider the development of its composition. It is necessary to select components depending on the size of the damage and cracks. For example, the composition for sealing large defects will differ from the one used to treat hairline cracks.

The most popular compositions for repairing concrete surfaces are: concrete, with the addition of epoxy resin, and cement-sand. Concrete mixture is most effective when it comes to sealing significant defects and cracks. It contains styrene-butadiene latex and Portland cement, which are mixed in a 1:2 ratio.

When making the mixture, the composition should turn out a little fatter than the previous one. After laying, the concrete mixture must be kept for about four days. Another mixture that can be used for such work is made up of sand and cement. It is more convenient to use for sealing cracks small size. The composition is made by mixing Portland cement and sand, ratio 1:3. For the sealer, styrene-butadiene latex can be used. The coating is waterproof and the adhesion of the mixture to the surface is improved. If the cracks are very small, less than 100 mm in depth, it is better to apply the composition using a pneumatic apparatus. This results in a better seal. You can choose shotcrete concrete for embedding - it will provide good strength for possible compression.

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

The widespread use of concrete is due to a wide range of advantages: strength, non-flammability, durability and low cost. Gradually, under the influence of various factors, structures begin to collapse. The reasons are different: non-compliance with the proportions when mixing, violation of the solution laying technology, mechanical damage, aggressive external environment. As a result, the material loses its design characteristics, cracks and chips form.

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

Situations in which their use is advisable:

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

Types and characteristics of mixtures

They are sold in the retail chain in the form of dry powders, which simply need to be diluted with water in certain proportions. Ready solution fills free space in concrete, reliably seals and strengthens the defective surface. To impart special qualities (frost resistance, moisture resistance, high speed hardening) use a variety of plasticizers, modifying additives, and granular fillers.

All of them are conventionally classified according to several criteria.

1. According to the complexity of the composition.

• One-component – ​​cement with different filler sizes.
• Two-component - epoxy of varying degrees of fluidity.
• Multicomponent – ​​polyurethane liquid.

2. According to the degree of compression.

• Shrinkable - mixtures that shrink when hardened in air. When shrinkage is difficult to calculate in advance required quantity layers. Depending on the complexity of the repair, apply 1-2 additional times. The main advantage is the low price.
• Non-shrinking - includes special additives with an expanding reagent. This allows you to obtain a non-separating and mobile solution that does not shrink and hardens quickly. With it you can easily repair any foundation, which ultimately turns out to be strong and durable. The only disadvantage is the high price.

3. As intended.

• Compositions for concrete structures subject 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.
• High-strength products for road surfaces and screeds. In winter they provide additional protection from frost.

4. According to the conditions of use.

• Molded - for screeds and others horizontal planes.
• Thixotropic - for correcting defects on walls.
• Frost-resistant - for outdoor concrete surfaces.
• Quick-hardening – for urgent repairs and leak repairs.
• Industrial and domestic use.

Using self-leveling (molding) types, you can repair planes up to 100 mm thick. Quick-hardening compounds are used for a working layer of no more than 40 mm.

How to choose mixtures for concrete?

When purchasing, you need to take into account the nature of the defect, the size of the damaged area and operating conditions. It is better to choose solutions that, after setting, do not delaminate and do not shrink.

The compatibility of the composition with the working surface and the level of adhesion are of great importance. Large manufacturers always have branded products in their product line. soil mixtures deep penetration, which bind concrete and provide reliable adhesion.

When choosing, you need to take into account the scale of the repair. Deep cracks, potholes and pronounced differences are leveled using coarse-grained mortars or fiber-reinforced mortars. For small chips and cracks, it is better to buy an option with increased plasticity containing fine fractions.

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

Repair technology

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

• Clear work surface from dust and debris and degrease.
• For better adhesion, treat the concrete with epoxy primer.
• Assess the scale of the repair and calculate the required composition. Experts recommend maintaining the thickness of the screed within 40 mm.
• Set up control beacons and lay the solution.
• Remove excess and level using a lath.
• Cover the finished surface plastic film and leave for 2 weeks to gain strength. During this time, the concrete should be 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 liquid types with increased plasticity.

2. Repair cracks.

First, all the cracks are widened and cleaned. To do this, you need to cut grooves around them to a depth of no more than 50 mm. This is convenient to do with a diamond wheel or grinder. Then select the debris with a chisel or hammer drill. Work area clean with compressed air or a vacuum cleaner, prime and apply the product.

• Gradually fill cracks on horizontal and inclined surfaces with the solution, without exerting strong pressure on it.
• To eliminate cracks on vertical planes, quick-hardening dry mixtures should be used.
• Internal voids and very deep cracks are filled by injection using special device– packer. Remove excess compound that comes out under pressure using a lath.

After hardening, the surface is sanded.

Review of popular brands

Manufacturer - Russian company Basf. Mixtures are used to repair defects of varying degrees of complexity.

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

2. Consolid Bars.

Compound Russian production Excellent for restoring vertical and horizontal surfaces. It sets quickly and does not shrink. Has a high degree of adhesion to concrete.

• Self-leveling – for horizontal and inclined planes.
• Thixtotropic – for the restoration of walls and various vertical surfaces. The line includes repair, finishing, reinforcing and moisture-resistant coatings.

A domestically produced product intended for the reconstruction of concrete of any complexity.

• Birss 28,29,30,30N – for light repairs of cracks and crumbled surfaces.
• 30С1, 58С1, 59С2 – for restoration of structures with an average degree of wear.
• 59С3, 59Ц - options for serious damage.
• RSM, RBM, 600VRS are used in cases of severe damage.

4. Knauf Flachendicht.

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

5. Ceresit CX5.

Restorative mixture for repair concrete products in conditions high humidity. It does not shrink during hardening and reliably protects against high and low temperatures.

6. Found.

• Innoline NC60 is a priming agent used for the restoration of all types of surfaces. Successfully used for installing and securing heavy equipment on a concrete base.
• Selform T112 – for walls and floors. Characterized by excellent grip and water-repellent properties.

Price

Name	Packaging, kg	Price per package, rubles
Emako	25	850-1700
Birss	50	400-450
Knauf	5	350-450
Ceresit	25	2700-3500
Consolid Bars	30	800-1500
Founds Innoline NC60	25	800-1200
Founds Selform T112	20	160-250
S.W.	25	240-260
Mapei	25	850-1300
Alit	25	1100-1700

Reliability and can serve for a long time. But it is possible that he is susceptible to destructive external influence. Over time, cracks and irregularities may appear on it, so in this article we will look at how to get rid of such damage using repair mixtures and compounds.

What is it

The restorative composition consists of:

• cement;
• sand;
• fillers;
• all kinds of additives that give the solution the qualities necessary for its strength.

Dry repair compounds for concrete can be used immediately; to do this, add water to them and mix thoroughly.

With the help of such solutions, deficiencies in concrete structures are eliminated, in particular:

• semi;
• stairs;
• bridge;
• wall;
• road.

Also, dry repair compositions are usually used for the following purposes:

• repair work of main structures that serve as load-bearing structures: concrete beams, floor slabs, columns and others;
• carrying out repair work on road surfaces (aircraft take-off strips, parking lots), concrete floors on industrial enterprises, warehouses;
• as a protection for surfaces made of .

Today there is a varied selection of concrete repair compositions, ranging from various manufacturers to the properties of the products. The price of the mixtures also has a wide range.

Compositions intended to eliminate defects are divided into two main types:

• injection molded, which are used for horizontal surfaces;
• thixotropic - for vertically located planes.

Advice: to increase the reinforcing properties, it is necessary to add fiber fiber to the repair products.

How to choose a mixture

When choosing, you need to take into account several indicators, namely:

• what kind of damage?
• what is the surface defect?
• conditions of its operation.

How to strengthen concrete surface?	Often, concrete surfaces that are subject to heavy loads have insufficient strength. Monolithic structures can be distinguished as concrete screed and floor slabs. They need to be strengthened with a deep penetration primer.
How to level a concrete surface?	Unevenness is the most common defect in concrete structures. In this case, you can also use a deep penetrating primer. Thixotropic dry mix is ​​excellent for vertical surface, since it is applied evenly to the plane, does not blur and sets well. Also this composition: high strength; resistant to frost and moisture; has only slight shrinkage.

When carrying out repair work on particularly important concrete areas, the use of reinforced fiberglass is most appropriate. In addition, there are special means, designed to carry out repairs in a short time, which harden quite quickly.

Advice: apply each layer no more than 35 mm thick. And, if the reinforcement in concrete structures is exposed, it should be treated with an anti-corrosion primer.

In order to level the horizontal surface, use a dry casting repair mortar for concrete. It has a liquid consistency compared to thixotropic ones.

The casting composition simply needs to be poured onto the concrete surface. In this case, one layer can be 100 mm thick. The composition has minimal shrinkage, it firmly covers the surface and sets instantly.

When repairing cracks in concrete, which often appear on its surface, the same mixtures that were used to level the surface are used. When choosing them, consider the conditions further exploitation designs.

When making such a mixture, the composition may contain different components that give the product certain characteristics, for example:

• frost resistance;
• hydrophobicity;
• reducing the hardening time of the solution.

How to level the floor surface

You can level the horizontal surface with your own hands. However, the work will require considerable effort, certain knowledge and techniques, but by adhering to technology, you can independently achieve the necessary quality. To level the floor, you will need a cement-sand screed.

Below are instructions for working with it:

1. At the first stage, clean the floor from dust and dirt. Remove the old coating and treat the surface with a primer to distribute the solution more evenly.
2. Determine the highest point from which the floor leveling will begin.
3. Install beacons, for which metal corners, pipes or profiles are suitable. Place them so that they are at the same level.

Tip: it is better to do this using a laser level.

1. Start pouring the screed. In this case, its layer should be up to 40 mm thick. A solution that has been mixed in advance in a metal or plastic container, pour it onto the surface, then continue leveling the fill using the rule.

After finishing pouring, let the screed dry well for a couple of weeks. The next day after completion, if the solution has managed to gain some hardness, remove the beacons and fill the seams with grout.

Tip: while drying, cover the screed with polyethylene film. Moisten the surface with water from time to time to avoid cracks and give the screed strength.

Repairs to horizontal concrete surfaces can be carried out using a self-leveling agent. It is used if there are small defects or irregularities on the surface up to 3 mm. The result is an absolutely smooth plane.

How to remove potholes

It happens that potholes form on the concrete surface.

1. First make an incision along the perimeter of the defect, its depth should be up to 20 mm. Use a grinder with a diamond blade for this purpose.
2. Remove excess concrete with a chisel or hammer drill.
3. Remove any remaining dirt and dust. To better remove all debris, you can use sandblasting equipment or a vacuum cleaner.
4. Apply an epoxy primer to the clean surface, which helps the product adhere to the concrete.

1. Fill the pothole with a special mixture, which can be repair compounds for reinforced concrete.
2. Remove excess mixture from the surface and level it with a lath or rule.

The patch must be left until it is completely dry. In this case, the product will be quite durable. The last stage is sanding the patch.

Conclusion

For repair work, it is better to use special dry mixtures instead of the standard one. concrete mortar. Such repair products have certain properties that will provide the coating with adequate strength. The video in this article will help you find additional information on this topic.