Concrete repair mixes

Properties of the waterproofing mixture CERESIT CX 5 (hydroseal):

• the beginning of setting after 3 minutes;
• quickly gaining strength;
• non-shrinking;
• waterproof;
• frost-resistant;
• has high adhesion to concrete and metal;
• does not contain chlorides;
• does not cause corrosion of reinforcement;
• suitable for indoor and outdoor use;
• environmentally friendly.

Instructions for the use of Ceresit CX 5 installation cement / hydraulic seal:

Substrate preparation:

The preparation of the bases should be carried out in accordance with SNiP 3.04.01-87.

The substrate must be solid, clean, rough, with sufficient load-bearing capacity and open pores.

The base must be cleaned of dust and dirt (efflorescence, oils, bitumen, etc.).

Unstable areas of the base should be removed.

Moisten the substrate if necessary.

Mounting cement can be used on substrates such as concrete, cement-sand mortars, ceramic facing bricks and natural stone masonry.

Execution of works:

A small amount of assembly cement is mixed with clean water until a homogeneous mass without lumps is obtained.

The consistency of the material is selected depending on the type of work performed.

• For stopping water inflows, anchoring and filling potholes on vertical bases, the material is prepared with a plastic consistency by mixing 4 parts by volume of cement with 1 part of water.

• For anchoring and filling cracks on horizontal bases, the material is prepared with a fluid-plastic consistency by mixing 3 parts by volume of cement with 1 part of water.

The mixture should be consumed within 3 minutes from the moment of preparation.

The gap between the anchor and the cavity walls should not exceed 20 mm.

With gaps of more than 20 mm, the assembly cement is mixed with quartz sand in a 1: 1 ratio and the mixture is brought to the required consistency with water.

The introduction of sand does not affect the setting rate of the material, but leads to a slight decrease in its strength.

When the water inflows stop, the water-developing defect is quickly filled with the prepared mixture at the time of its setting (determined by the change in consistency and active heat release) and kept there until it is completely cured.

Fresh remnants of the mixture can be easily removed with water, dried ones can only be removed mechanically.

Recommendations for working with Ceresit CX 5 installation cement / hydraulic seal:

Work should be carried out in dry conditions, at an air and base temperature from +5 to + 35 ° C and a relative air humidity not exceeding 80%.

The setting speed of the assembly cement can be adjusted by the mixing water temperature - the lower the mixing water temperature, the slower the material sets.

STORAGE

In dry conditions, on pallets, in original undamaged packaging - no more than 12 months from the date of production.

The product reacts actively with moisture, therefore, incompletely used material should be kept hermetically sealed and used as soon as possible !!!

TECHNICAL CHARACTERISTICS OF CERESIT CX 5 MOUNTING CEMENT:

Rigid waterproofing Ceresit CR 65 can be used:

• for external and internal waterproofing of buried and underground structures (including in combination with Ceresit sanitizing plasters);
• for waterproofing small monolithic baths of indoor pools and water tanks for household and drinking purposes;
• for waterproofing wet rooms (bathrooms, showers, toilets, kitchens, industrial premises, etc.) under tiled cladding;
• to protect cooling towers, hydraulic engineering and treatment facilities, tunnels and other concrete structures from moisture and frost destruction;
• for filling holes and voids when injecting masonry in old buildings (see CO 81).

On deforming substrates, terraces and heated screeds, add CC 83 modifier (6.0 l of modifier + 3.0 l of water per 25 kg of dry mix) to the mix, or use a two-component analogue.

The waterproofing should be protected from mechanical damage by means of tiled cladding or not containing gypsum plaster or screed, which you can also buy from our company.

Self-production

A repair compound for concrete can be made independently for work on the arrangement of a private house, outbuildings, etc.

You will need to mix the following components:

• 1 part cement powder;
• 3 parts of clean fine sand;
• glue (PVA or Bustilat) with water in proportions of 1: 3.

It is required to mix sand and cement powder, mix with other ingredients and prepare a homogeneous mass. When mixing, a special mixer is used. The composition is prepared on the eve of work to prevent preliminary solidification. The mixture is suitable for finishing floor coverings, vertical panels, etc.

Classification

In most cases, repair mixes are sold in the form of a powder, which must be diluted with water before use. Some manufacturers add certain components to their products to improve the properties of the concrete base.

Repair substances are classified according to their destination:

1. for the regeneration of concrete systems that are under stress, for example, load-bearing building structures, beams, columns;
2. for the reconstruction of concrete floor coverings;
3. to protect reinforced concrete structures from rust.

In addition, there is a division into dry mixes and injection molding.

Dry mixes are used to recreate the original properties of concrete and to strengthen solid structures.

Due to such parameters as strength and endurance in conditions of high humidity, concrete waterproofing is often performed with restoring materials. The dry material is environmentally friendly, safe for human health, therefore it can be used for domestic purposes, for example, to restore the previous type of containers for supplying drinking water.

The last criterion determines the division of repair mixes into industrial and household ones.

Casting masses are used to fill cracks and small pits previously cleaned of dirt. They expand during pouring, reliably adhere to concrete, and practically do not shrink when solidified. Filling the resulting voids, the solution hermetically closes and seals the damaged area. Casting mixtures are used to restore horizontal planes.

According to the complexity of the initial composition, mixtures are distinguished:

• mono-component - cement compositions with large and small particles;
• two-component - prepared using synthetic resins;
• multicomponent - liquid polymer repair compounds.

The modern market also provides restorative compositions for concrete with limited operating conditions.

Fast-acting mixture for repairing concrete bases

The name itself suggests that such products dry out and harden quickly.As a rule, within 30 minutes after filling, work can be carried out using loading heavy equipment.

These types of mixtures are very helpful when it is necessary to make repairs as soon as possible. For example, in factory warehouses, where different goods are constantly moving, and downtime due to forced repairs will be a real disaster. If you need to carry out the repair of a concrete structure as quickly as possible, but at the same time qualitatively, then high-speed mixtures are the best solution.

Shrink-free repair product

Shrinkage refers to deformations that occur as a result of a reduction in the amount of cement stone in a concrete solution. They are formed during the volatilization of water from the adhesive mixture, therefore, the more liquid is required for the mortar, the deeper the shrinkage will be.

A simple building mixture shrinks up to 5 mm, which is considered a rather large figure in the construction business. Such shrinkage can provoke the appearance of shrinkage cracks.

Thixotropic mixture

This type of repair substance is specially designed for the repair of vertical surfaces and inclined walls. Due to its design features, it does not require the use of an auxiliary lathing.

Two-component cementitious waterproofing CERESIT CR 166 can be used:

• for waterproofing foundations, hydraulic structures, terraces, balconies, building elements below ground level, etc.;
• for waterproofing baths of outdoor and indoor pools and water tanks for domestic and drinking purposes up to 50 m deep;
• to protect concrete and reinforced concrete structures from carbonization (on piers, retaining walls, tunnels, bridges, cooling towers, supports, etc.).

Possesses high chemical resistance to alkalis, fertilizers (at pH> 4.5), hydraulic oil, 10% sodium chloride solution, sodium hypochlorite, sodium carbonate (soda), sugar, 10% ammonia solution, acetone.

In the presence of a hydrostatic head, the waterproofing must work against the pressure. The waterproofing coating should be protected from mechanical damage by tiling or plaster-free plaster or screed, which you can also buy from our company at a discount from the retail price.

How to choose?

To choose and buy a high-quality repair mixture, you need to follow the advice of professionals.

• At the first stage, it is necessary to conduct a visual inspection of the concrete surface and determine:
  • kind of flaws;
  • their sizes;
  • possible loads.
• To choose a manufacturer, you should consider at least two options, compare the cost of products in this segment, its features and study the composition (the mixture must be non-toxic and safe for humans).
• Having calculated the thickness of the future layer and the area of ​​reconstruction work, you need to buy the appropriate amount of the mixture.
• If you need to strengthen a concrete foundation, it is better to buy a deep-penetrating mortar.

• Tikstotropic mixtures are best suited for strengthening vertical surfaces. They have a thick consistency, adhere well to concrete, so they will firmly adhere to the walls.
• Surface leveling mixtures must have high adhesion properties.
• Important characteristics that you need to know before buying a repair mixture are:
  • hardening period - the less it is, the better;
  • material consumption - the instructions on the package usually indicate how much of the mixture is required to complete a specific task;
  • the degree of protection against ultraviolet rays of the sun, frost and chemical influences;
  • the degree of shrinkage - there are non-shrinking repair mixtures on sale, it is better to buy them.

For information on how to repair cracks in concrete, see the next video.

Peculiarities

After the creation of mixtures for the reconstruction of concrete, the builders no longer needed to completely replace the deformed sections.Now, thanks to special repair substances, it is possible not to spend large sums and time on restoring the original parameters of the concrete system. With the help of restorative mixtures, the defective product gets an attractive appearance and returns to its original properties.

The composition of the repair joints is designed in such a way that the concrete base and the mixture itself reliably adhere to each other. After they have completely solidified, you do not have to worry that the updated system will soon become unusable. High-quality repair mixtures from well-known manufacturers do not need to be quickly replaced, since they differ in a number of positive properties.

Among them:

• frost resistance;
• resistance to sharp drops and rises in temperature;
• vapor permeability;
• long period of service;
• high level of adhesion;
• antiseptic abilities;
• water repellent capabilities.

Fine-grained repair and restoration mixture for concrete (5 - 30 mm)

Fine-grained repair and restoration mixture CERESIT CD 25 intended for the repair of defects (chips, potholes, voids, caverns, etc.) and restoration of the geometric dimensions of concrete and reinforced concrete structures with a layer thickness of 5 to 30 mm.  

Not suitable for use on lightweight and aerated concrete, masonry, lime and gypsum plasters.

Repair mixture Ceresit CD 25 is part of the Ceresit system, developed for the complex repair, restoration and protection against corrosion of concrete and reinforced concrete structures with signs of partial destruction: water tanks (water treatment plants, swimming pools), flyovers, facade elements (balcony slabs, columns), foundations, retaining walls, refrigerating and freezing chambers, chimneys etc..

Properties of the concrete repair mix CERESIT CD 25:

• fast hardening;
• high strength;
• water and frost resistant;
• vapor permeable;
• crack-resistant;
• reinforced with microfibers;
• resistant to anti-icing agents;
• suitable for indoor and outdoor use;
• environmentally friendly.

Instructions for the use of repair and restoration mixture for concrete CERESIT CD 25:

Substrate preparation:

The preparation of the base must be carried out in accordance with the requirements of SNiP 3.04.01-87.

The concrete must have a compressive strength of at least 30 MPa.

The substrate must be free of dust, efflorescence, oils, bitumen and other contaminants. Weakened concrete layer, corrosion products, laitance, formwork release agent, paint coatings must be removed.

The concrete surface must have a rough, open-cell structure.

For filling concrete defects with a depth more than 30 mm it is recommended to use a coarse-grained repair and restoration mixture Ceresit CD 22.

Moisten the substrate until it is saturated, avoiding water accumulation, and apply an adhesive layer of Ceresit CD 30 mixture.

Ceresit CD 25 mix applied to the still wet adhesive layer - about 30-60 minutes after its application.

If the specified time is exceeded, it is necessary to wait until the previous layer has completely hardened and apply a new adhesive layer.

In the presence of bare reinforcement, remove the concrete behind the reinforcement to a depth of 10-20 mm, clean the reinforcement from concrete and rust with a steel brush or dry sandblasting and blow with compressed air with a minimum residual oil content.

To apply two layers for reinforcement adhesive mixture Ceresit CD 30.

The first layer should be applied no later than 3 hours after cleaning the reinforcement, while the surface of the reinforcement should be slightly damp. When the first coat has hardened (approx. 3 hours after application) apply a second coat of adhesive mixture.

Execution of works:

To prepare the mixture, take a measured amount of clean water with a temperature of +15 to + 20 ° C.

The dry mixture is gradually added to water with stirring, achieving a homogeneous mass without lumps.

Mixing is carried out with a mixer or a drill with a nozzle at a rotation speed of 400-800 rpm.

Then stand technological pause about 5 minutes to ripen the mixture and mix again.

The mixture should be used up within 30 minutes from the moment of preparation.

The prepared mixture is applied to the base using a steel trowel or plastering trowel.

The mixture can also be applied by dry gunning or spraying.

When applying several layers of the mixture, the next layer should not be applied later than 3 hours after the previous one, according to the rule Wet on wet.

If the specified time is exceeded, you must wait 24 hours, moisten the base, apply adhesive layer made of Ceresit CD 30 mixture and after 30-60 minutes start applying the next layer of the repair mixture.

Repair mixture Ceresit CD 25 can serve as a finishing layer or not earlier than 2 days after application, its surface can be leveled with Ceresit CD 24 putty.

For additional protection against carbonization and frost destruction, it is recommended to apply a coating of Ceresit CR 166 waterproofing mass or Ceresit CT 44 acrylic facade paint not earlier than 3 days after applying the mixture.

Fresh dirt with the mixture can be easily washed off with water, dried - can only be removed mechanically.

Recommendations for working with repair mortar CERESIT CD 25:

Work should be carried out at an air and base temperature from +5 to + 30 ° C and a relative air humidity not exceeding 80%.

During the period of drying and setting of the mixture, it should be protected from contact with water, exposure to negative temperatures and too fast drying under the influence of sunlight and wind.

How to choose the right one

A cement-based repair mixture can be made independently, however, a wide selection of materials on the construction market allows you to use ready-made, high-quality material in different price categories.

The fundamental point in choosing the type and grade of the composition that is supposed to be used in the work is the type of defect and its size, as well as what kind of load on the object will be given in the future. In the case when it is necessary to strengthen the base of the structure, it will be advisable to apply a deep penetration primer. For working with vertical surfaces, it is optimal to use dry mixes due to their ease of use.

For filling cracks, mixtures containing fiber are perfect. Also, when choosing a mixture for work, it will not be superfluous to study the information on the label, which indicates the period for which the composition solidifies, its required consumption and other useful characteristics.

How to properly prepare and apply a repair mixture using the example of Ceresit CN83, see the following video.

The choice of the repair mixture

When choosing a high-quality repair and restoration mixture, it is most reliable to use the recommendations of specialists. Some of them are listed below.
How to choose a repair mixture

First, the concrete structure is examined to determine the type of damage, the size of cracks or chips, and to determine the loads on the unit being repaired. To choose a brand of repair mixture, study the characteristics of two or more compositions, compare prices and other features of materials, check out the working composition. The main requirement for the components of the mixture is non-toxicity and safety for people. If a simple leveling of the surface is assumed, then the mortar should have high adhesion.

Comparison of the parameters of some brands of repair compounds:

The most important parameters of the repair mixture:

1. Curing time. The shorter the curing period, the better the surface to be repaired will be.
2. Consumption, which is indicated on the package.
3. The level of protection against UV radiation, negative temperatures and aggressive environment.
4. The possibility of shrinkage of the mixture.

After calculating the thickness of the repair layer and its area, the required amount of the repair mixture is acquired. When repairing a foundation based on concrete mortars, a deeply penetrating mixture is optimal. For the repair or restoration of walls or other vertical surfaces, a thixotropic mixture with a thick consistency and high adhesion is used.

Mixture application technology

As with any work, before applying the repair mixture, it is necessary to clean the surface, removing dust and debris from the deformed areas. This will make it possible to determine the required amount of material. After that, the crack deepens by about 5 centimeters. The reinforcement cage is thoroughly cleaned, which is subsequently covered with anti-corrosion primer.

Deep cracks will need additional reinforcement. Then dust is removed and the treated areas are moistened.

You can prepare the mixture for repair work yourself.

Further actions depend on the type of material used.

The treated surface must be smoothed out with a steel trowel, masking defects and irregularities. After the mixture has set, which will take about half an hour, this action must be repeated.

To prevent cracks from appearing on the applied material, it should be damp for about a day. When exposed to high temperatures, this condition must be extended to three days. For humidification, you can use a spray bottle or a regular hose with water. Next, the treated area must be covered with a waterproof material.

Manufacturers and range of repair mixes

The existing dry or molded mixtures have different composition, differ in properties, have different consumption, price, volume and weight in the package. Below is a list of the most popular Russian and foreign manufacturers:

1. Russian mix Emaco. Improves the technical and operational characteristics of damaged concrete structures. Composition: crushed quartz sand, environmentally friendly viscous polymers. Emaco can seal cracks of 2-20 mm. Repair mix Emaco has a high resistance to negative temperatures, which allows you to work with it in the winter.
2. Russian repair mix "Birss". The frost resistance of this mixture is such that the regeneration of the concrete surface can be carried out even at low temperatures outside. In addition, the composition has high strength and good moisture resistance.

Mix of Russian production Emaco

1. Consolit Bars is a molding mixture made in Russia. It is used for the repair and restoration of various structures and structures made of concrete. Does not shrink, has a high degree of adhesion.
2. Ceresit CN 83 masonry mixture. Designed for operation in high humidity, while it does not shrink and has a moisture-resistant surface after hardening. You can work with the mixture at low temperatures.
3. Knauf waterproofing mixture. Leveling the concrete surface, forming a moisture-resistant and vapor-proof film. The mixture is environmentally friendly, designed for indoor and outdoor use.
4. Russian repair mix Indastro. The repair and restoration mixture Indastro NC60 is used for the restoration, reconstruction and restoration of any concrete structures, structures and foundations.
5. Italian repair mix Mapei. Easy restoration or repair of any concrete surfaces. The mixture shrinks slightly, but cracks do not form. The hardened surfaces are resistant to abrasion and mechanical wear. The composition of the Mapei SW brand is designed to work in reinforced concrete structures. It behaves stably and steadily at different temperatures and humidity, creates an anti-corrosion moisture-resistant coating that protects concrete reinforcement.The hardened mortar is an excellent waterproofing agent.

Mapei - mix for the restoration of reinforced concrete structures

1. Russian composition "Mountain Khrustalnaya". It is used for the repair and restoration of concrete, for the restoration of damaged concrete, reinforced concrete, foam concrete and aerated concrete structures. Designed for filling gaps in concrete, filling technological holes and other recesses, strengthening chips, eliminating erosion and caverns in concrete structures, correcting defects in old reinforced concrete objects, repairing and restoring concrete floors and other surfaces, including floors.
2. Siltek is a mixture made in Russia. Grade B25 is constantly in demand in the construction market, developed for the repair and restoration of any surfaces made of concrete and cement, qualitatively eliminates defects that may arise after pouring joints between floors and panels.

Manufacturers

The construction market offers a number of manufacturers of repair mixes for concrete, among which the following companies are especially popular:

Ceresit is one of the most popular brands of concrete repair mortars. The range of its positive properties is very wide. The composition is distinguished by the absence of shrinkage, calmly tolerates the effects of negative temperatures and water. The mixture is applied in layers of 5-35 millimeters. It is plastic due to its viscosity, it is able to reliably fill all cracks and cracks, therefore it is used when working on both horizontal and vertical surfaces. It tolerates mechanical loads well, it is used both for internal and external work.

The mixture is applied to cement-sand screeds made no more than a month ago. The age of the concrete to be repaired with this material should not exceed 3 months. The work is recommended to be carried out within the temperature range from 5 to 30 degrees.

To prepare the composition, water is taken at a temperature of 15-20 degrees, into which the mixture is gradually added. For 3 liters, you need about 25 kilograms of the mixture. If the volume of water exceeds the required limits, this can adversely affect the strength and durability of the material. After laying on a wet, previously prepared layer, the mixture is leveled to smooth out irregularities and imperfections.

Ceresit compounds have several grades, the main difference of which is their grain size. Mixtures CD 22, 23, 25, 26 and CN 83 are isolated.

Particularly popular is the composition of the MBR-300 "Mountain Khrustalnaya". It can be used both in the construction of objects and in their subsequent repair. The fiber content increases the positive properties of the material. It is used on vertical and horizontal surfaces and has good compatibility with materials made of reinforced concrete, brick, stone and concrete.

The material practically does not shrink, has good water resistance, frost resistance, firmly adheres to the surface. This composition can be prepared and applied independently, subject to technology compliance. No specialized skills are required for its installation.

The mixture can be used both during construction and during repairs. It does not require additional priming and leveling, and the application process usually does not cause problems. The curing process is fast enough. Also, an undeniable advantage is the relatively low price in comparison with similar materials. It is used both for self-carried out repairs and for the work of professional craftsmen.

More about the composition and application of repair mixes

The repair mixtures were developed specifically to carry out local filling of cracks and chips, waterproofing of the destroyed surface, without replacing a section of concrete with disturbances. All repair mixtures, including Ceresit, are capable of restoring the technical and operational characteristics of concrete in the damaged area to the original ones.The impact of the mixtures is based on the fullest possible adhesion (penetration and adhesion) of the repair mortar into the concrete structure with the subsequent provision of certain qualities of the repaired area, including:

1. Frost resistance.
2. Immunity to contrasting temperatures.
3. Water vapor permeability.
4. Long service life of the repaired site.
5. High coefficient of mixture penetration into concrete.
6. Antiseptic and water-repellent properties.

Repair of a damaged section of a concrete surface