Concrete additives. Additives to concrete - types, characteristics, purpose

Concrete is the most well-known and commonly used building mixture consisting of cement, aggregate and water. But since it is used not only for constructing walls and ceilings of residential and public buildings, but also for hydraulic structures, foundations, structures special purpose(supports of bridges, viaducts, etc.), then in each individual case the substance that has the general name “concrete” cannot be the same.

Every time when designing objects, structures are calculated taking into account all the conditions not only of their construction, but also of their further operation. And since the operating conditions are different, the concrete solution should also be different.

Therefore, to give concrete the desired properties, various additives are used that change not only the properties of the liquid concrete mixture, but also the hardened concrete itself.

Additives for concrete - classification

There are a lot of additives, which is why they are classified differently. The following is one of the most commonly used classifications:

1. Concrete modifiers - can increase the strength of the concrete mixture and its frost resistance, reduce its permeability, extend service life ready-mixed concrete. At the same time, they do not reduce the mobility of the mixture, which increases the efficiency of its use and facilitates the work.
2. Mobility regulators - they are used in hot weather or in cases of long-term transportation of concrete in order to maintain the necessary plasticity.
3. Plasticizing additives. Their use allows you to reduce concrete consumption without reducing its strength. They also make it possible to improve the mobility of the solution, increase its density, and in some cases, water resistance.
4. Anti-frost additives - used when laying concrete in winter period at temperatures down to -15 and even up to -25 degrees.
5. Additives for self-compacting concrete - used when it is necessary to fill thin-walled concrete structures.
6. Additives to accelerate the development of strength - improve this indicator in the first day after laying the mixture, and also increase the strength of already hardened concrete.

There are situations when it is necessary to improve several indicators of a concrete mixture at once. Then they use complex additives that can affect several indicators at once.

The use of several additives in such a situation can lead to unpredictable results, and a correctly dosed complex preparation guarantees the required quality of concrete.

All substances added to the concrete mixture can also be divided into 2 large groups:

1. (powders, emulsions and aqueous solutions) - are introduced into concrete in small quantities.
2. Finely ground substances (finely ground mineral substances) are used when it is necessary to save cement and produce durable, dense concrete.

Chemical additives divided according to the effect they have on the concrete mixture:

• hydrophobic;
• increasing the plasticity and mobility of the mixture;
• anti-frost;
• reducing the separation of liquid from solution;
• stabilizers that do not give liquid concrete exfoliate;
• hardening accelerators;
• regulators of deformation processes;
• retarders;
• gas- and foam-forming additives that increase the porosity of concrete;
• increasing resistance to aggressive environments and corrosion.

Concrete modifiers

These substances are intended for the production of special-purpose concrete with high technological properties: low water permeability (grade not lower than W12), high strength (up to B125), corrosion resistance and durability.

Some modifiers are designed to produce expanding, prestressing and shrinkage-compensating concrete and mortars.

These additives are mainly used for the production of normally and prestressed products using vibrocompression and molding methods.

Concrete mixture mobility regulators

They are used in situations where it is impossible to organize the production of a concrete mixture of the required quality directly next to the construction site and it is necessary to transport concrete from afar. These substances are also necessary when the production technology involves a long process of laying the mixture.

Typically, these substances are included in complex supplements.

They are made from:

• inorganic substances;
• organic materials;
• organomineral combinations.

Natural additives are produced mainly from waste from the agrochemical, petrochemical and forest processing industries.

Additives of inorganic origin are made based on concentrates of formaldehyde and naphthalene sulfonic acid.

They give the mixture the following qualities:

• high turnover;
• increased strength;
• resistance to temperature changes.

These substances reduce costs concrete works, reduce cement consumption in the production of concrete, have a positive effect on the adhesive properties of reinforcement (improves the adhesion of reinforcement to concrete).

For work such as pouring columns or densely reinforced structures, the use of these substances is mandatory.

Antifreeze additives

During the cold season, the hardening process of concrete slows down significantly, which has an extremely negative effect on its strength indicators - the concrete becomes loose, and its frost resistance index decreases.

If on construction site It is not possible to use heating of concrete, then they use, which reduce the freezing point of water and, thus, normalize the hardening process of concrete.

Antifreeze additives are a liquid with a density of approximately 1.4 l/kg with a mass fraction of calcium nitrate from 42 to 45% and an activity of hydrogen ions from 5 to 8 pH. The color of the additive depends on the manufacturer and can be light gray, yellowish or even dark brown.

These additives have the following effects on concrete:

• accelerate strength gain;
• increase the water resistance of concrete;
• increase its mobility;
• The corrosion inhibitor contained in the additive protects against oxidation.

The use of anti-frost additives prevents the appearance of efflorescence on the surface of a concrete structure, increases its strength, and allows the use of cement of lower grades for the mixture, which reduces the cost of concrete products.

These substances are introduced into the concrete mixture when pouring monolithic and prestressed products - bridges, dams, dams, oil and gas platforms.

The main requirement for these concretes is their stability to water separation and delamination.

Such concretes are used in densely reinforced structures, when conventional compaction of the mixture is impossible, so concrete is needed that can only be compacted by its own weight.

Hyperplasticizers are added to these concretes, which make it possible to obtain concrete with ultra-high performance properties.

They are used for the construction of monolithic, seamless, high-strength, shotcrete, reinforcement and restoration of structures.

Additives to accelerate strength gain

Most often, aqueous solutions of calcium chloride, sodium chloride and other chloride salts are used here. They accelerate the hardening of concrete and are used in the construction of the following structures:

• prefabricated reinforced concrete structures;
• densely reinforced and thin-walled structures;
• products of non-standard shapes;
• swimming pools.

All these substances are mainly used for industrial production concrete and products made from it. In private housing construction, the most used are anti-frost additives and concrete mix hardening accelerators.

What to consider when using concrete admixtures

When purchasing a supplement, pay attention to the manufacturer. Many imported additives are designed only for concrete made from high-quality components that are rarely used. It is better to purchase a domestic supplement from a reliable manufacturer.

When mixing concrete with additives yourself, you must strictly observe the proportions, otherwise you may end up with low-quality concrete.

Also learn exactly how the additive should be administered - some are introduced with water, while others require pre-mixing with one of the dry components of the mixture.

To improve the quality of a concrete mixture, manufacturers use various additives into its composition. Additives to concrete improve many characteristics of the mixture used. By changing the composition, resistance to low temperatures and corrosion, hardening time decreases, strength changes, etc.

Types of impurities

Each additive is responsible for certain properties of the resulting mixture. According to qualitative parameters, classification into categories is carried out as follows:

• plasticizing agents (water-soluble preparations, stillage from sugar molasses);
• air-entraining (sulfonol, tree resin);
• hardening accelerators (sodium and calcium salts, polyamine resin);
• retarders (sodium ethyl siliconate, polyhydroxyloxane, molasses);
• sealing agents (iron salts, calcium nitrate, aluminum sulfate, ethylene glycol resins);
• corrosion inhibitors (potassium and sodium dichromate, sodium nitrate);
• gas-forming agents (aluminum powder, polyhydroxyloxane);
• antifreeze (calcium and sodium chloride, calcium and sodium nitrate, urea) additives to concrete.

The listed types can be used as a single component or used in combination with each other. Combinations of added substances a large number of. Let's consider the properties of each impurity from the listed classification.

Plasticizing

The lower the water-cement ratio in the concrete mixture, the stronger the structure made from this material. But with the very minimum amount of liquid in the composition, the concrete mixture turns into a thick conglomerate.

The inclusion of additional components ensures the plasticity of the mixture without adding excess liquid. Also, plasticizers in concrete increase the strength and resistance of structures to frost.

Plasticizers are divided into four groups based on their reduction in water use:

• weak (less than 5%);
• average (5%);
• strong (10%);
• super strong (more than 20%).

Air-entraining

Adding such impurities to the composition allows you to obtain a porous structure of the mixture. Due to this, the frost resistance of reinforced concrete structures increases.

The pores inside the material provide free space for water to expand during freezing. The percentage of air-entraining additives should be minimal, because a large amount of impurities reduces the strength of the mixture.

These additives are used to speed up the hardening process of concrete. Low ambient temperature slows down the hydration process of concrete. The accelerator significantly reduces the hardening time, which allows the use of multi-layer pouring.

The process cycle can also be slowed down by the addition of other impurities that retard hardening. In this case, the accelerator compensates for the loss of time.

Retarders

They are used in cases where it is necessary to increase the time interval for maintaining the survivability of the mixture. Use in the first case justifies itself when the finished mixture needs to be delivered to the construction site, which is located at a great distance from the production site. Also when the technological process involves the phased use of concrete mortar. The moderator in this case allows you to save liquid state solution for a long time.

Seals

Increasing the density of the mixture contributes to its durability. The compactor fills the space between the concrete grains, which leads to increased strength. Also, these components help to reduce pores, which significantly increases the impermeability of the structure.

Corrosion inhibitors

The principle of their operation is the formation of an oxide film on the anode. Additives introduced into concrete in small quantities will protect the reinforcement from corrosion. Inhibitors cannot be used in combination with chlorides because they contribute to the destruction of the oxide film.

Gas-forming

Additives are used for the production of aerated concrete. They provide increased water resistance and reduced separation of the mixture. In the process of obtaining the mixture, gases are formed in a volume of 1.5–3%. This concrete structure improves frost resistance, but reduces the strength properties of the material.

Anti-frost

They allow concreting work to be carried out at temperatures down to –25°C.

The main task of these impurities is to accelerate the process of removing liquid from solution. Antifreeze additives for concrete make it possible to carry out work at sub-zero temperatures without additional heating.

Selecting a Component to Add

Additives that are introduced into concrete must be selected in accordance with the requirements for the technology. The selection of certain components should solve the following problems:

• improve technological properties concrete;
• increase strength and water resistance;
• increase resistance to frost and corrosion;
• reduce the amount of time for heat treatment;
• reduce the consumption of expensive cement and aggregate;
• regulate the mobility of the mixture.

You should also take into account not only the quality indicators of the mixture, but also the operating conditions. To achieve the required conditions, various classifications of additives and their combinations are selected.

The introduction of plasticizing and air-entraining impurities or their combination into the composition slows down the hardening process if curing is carried out under natural conditions. In this case, hardening accelerators must be added.

This condition is especially relevant if the ambient temperature is less than 10°C. Additives to concrete that accelerate hardening reduce the total time to 2-3 hours.

Heat treatment

If structures are subject to temperature influence, then the addition of plasticizing and air-entraining components without increasing the setting rate is carried out only in one case. This occurs when the process cycle is 13–14 hours for Portland cements. The holding time before the start of heat treatment must be at least 2 hours, and the temperature during the cycle must be increased by no more than 15°C in one hour.

Saving cement

To reduce the amount of cement, plasticizers, water-repellent admixtures and hardening accelerators are added to the concrete composition. General value Cement savings for weak plasticizing components range from 5 to 8% of the total volume.

If effective plasticizing additives for concrete are used, savings increase to 12%.

Heavy Duty Structures

The concrete mortar from which they are made is a multicomponent composition. It contains effective plasticizers, air-entraining admixtures and hardening accelerators. The question of saving cement in the manufacture of critical structures is not raised. It remains the main component providing strength parameters. Also, to obtain high-strength concrete, special technologies are used that ensure the required quality of construction.

Calculation of the amount of additive

Only the correct dosage of impurities can ensure the required quality of the material. Empirically, the amount of additive that is added to concrete can be determined using the following formula:

Рд = Рц*х/ γ*с,
where Рд – cement consumption, kg; x – % of admixture dosing based on the mass of cement; γ – density of the additive solution; с – additive concentration, %.

Рк = Р(1 - а/100),

where a is the value of reducing binder consumption, %.

Example

Let's calculate the amount of additive for the M300 brand. Cement consumption is 350 kg. It is necessary to introduce a plasticizing component – ​​technical lignosulfonate. We reduce cement consumption by 5%, the density for this indicator is 1.021 g/cm³. We perform the calculation:

• we determine the cement consumption taking into account additives: Rc = 350 (1–5/100) = 332.5 kg;
• it is necessary to determine standard indicators, the dosage of the additive intended for concrete, based on the mass of cement, is 0.1–0.5%, select the average value x - 0.3%;
• we calculate the amount of additive: Rts = 332.5 * 0.3/5 * 1.021 = 19.5 l.

The composition with the inclusion of the additive in the concrete solution will change in the following ratio: cement - 332.5 kg, technical lignosulfonate - 19.5 l.

For concrete, mortars and dry building mixtures

Waterproofing concrete additive "D-5" improves almost all the basic characteristics of concrete and mortars. It significantly increases strength, waterproof, sulfate resistance, frost resistance and adhesion of concrete and mortars, while being an effective plasticizer and hardening accelerator. Supplement D-5 can ensure continued mobility concrete mixtures during few hours. Hydraulic concrete and mortars with waterproofing additive D-5 are purchased unique property self-healing of through cracks that may form during the operation of structures. Self-healing of cracks occurs when water filters through these cracks.

Consumption

Composition and application

Attention! Before use, be sure to read.

Additive D-5 does not contain components hazardous to cement stone and reinforcement; it does not form toxic compounds in air and water. In the presence of other non-toxic substances and when exposed to climatic factors, it does not have a harmful effect on environment. Additive D-5 is approved for the production of concrete and reinforced concrete structures and products in contact with drinking water.

Additive D-5 is available in the form of a light beige powder. It can be used both in dry and liquid form. To obtain a liquid additive, it is necessary to mix the dry additive D-5 with clean drinking water in accordance with the manufacturer’s instructions.

Application area:.

• foundations
• underground parts of buildings and structures
• bridges
• tunnels
• hydraulic structures
• sea ​​and river ports, piers
• tanks for drinking water
• swimming pools
• wastewater treatment plants and etc.

as well as in structures that are subject to increased requirements for strength and durability:

• high-rise buildings and structures
• airfield runways
• cooling towers
• grain storage
• power line supports
• TV towers
• fortifications
• load-bearing prefabricated reinforced concrete structures, including pre-stressed (floor slabs, columns, pillars, beams, trusses, bridge structures, sleepers, pressure and non-pressure pipes, etc.).

Advantages and qualities

Basic properties:

1. Increases the water resistance of concrete to W 20 or more. This makes it possible to completely eliminate any other additional waterproofing of concrete, while the high water resistance of concrete is maintained for the entire period of operation of the structure;
2. Increases the strength of concrete by 50% - 100% compared to concrete without additives;
3. Accelerates the hardening process of concrete. The normalized 100% strength is achieved on 5 - 7 days of hardening under normal conditions;
4. Increases the sulfate resistance of concrete using ordinary Portland cement by 3-4 times;
5. Increases concrete adhesion by 50-70% and gives concrete the ability to self-heal through cracks up to 0.8 mm wide, which may appear in a structure during operation due to dynamic loads, including seismic ones. IN normal conditions this property is manifested in the fact that during long breaks in concreting (a month or more), the joints between old and freshly laid concrete “grow together” and do not leak even high blood pressure water;
6. Plasticizes the concrete mixture. Increases the mobility of the mixture from P1 to P4-P5 or reduces water consumption by 15-30% while maintaining the mobility of the concrete mixture;
7. Regulates the persistence of mobility of concrete mixtures for 3 hours or more (even in hot climates at air temperatures up to +50°C);
8. Increases frost resistance to F400;
9. Gives concrete antifreeze properties (up to - 5°C) in massive structures;
10. Allows you to reduce deadlines monolithic construction by no less than 25-30% due to the rapid increase in concrete strength, reducing the time it is kept in the formwork and completely eliminating all additional work By external waterproofing concrete;
11. Allows you to eliminate the process of heat and moisture treatment in the manufacture of prefabricated reinforced concrete products, replacing it with heating in a “thermos” at a temperature of 30 - 40°C;
12. Allows you to reduce cement consumption by 15 - 20% without reducing the strength and durability of concrete;
13. Significantly reduces (or completely eliminates) concrete shrinkage;
14. Increases protective properties concrete in relation to steel reinforcement;
15. Increases the adhesion of reinforcement to concrete by no less than 30%;

Additive D-5 is recommended for use (including shotcrete) when repairing premises with high humidity, during manufacture concrete screeds(including under “warm floors”), as well as in the production of dry construction mixtures and the production of foam concrete. Additive D-5 is also recommended for use in backfill mixtures used in filling mine workings, as well as in the manufacture of compositions for cementing concrete spaces during the construction of hydraulic tunnels.

Package: bags of 1 kg and bags of 18 kg.

Shelf life: 24 months in dry conditions from the date of manufacture.

After the expiration of the guaranteed shelf life, the D-5 additive must be tested. When positive results tests, the D-5 additive can be used for its intended purpose even after the expiration of the warranty period.

Instructions for use of additive D-5

Before using the D-5 additive at construction sites or at precast concrete plants, it is necessary to conduct preliminary laboratory tests of the additive in order to determine its effectiveness when interacting with those cements and aggregates that are used in each specific concrete plant. It is recommended to test one control concrete composition (without additive) and three main ones: with an additive dosage of 1.5%, 2% and 3% by weight of cement, and all compositions must have the same cone slump.

When making concrete or mortar, the D-5 additive (in dry or liquid form) is introduced into the concrete mixer simultaneously with water or cement. The mixing time of the concrete (mortar) mixture after adding all components is at least 30 seconds (determined separately in each specific case, depending on the design of the concrete mixer).

Transportation of concrete mixture to the construction site must be carried out in concrete mixer trucks with constant mixing of the concrete mixture. The time from the moment of preparing the concrete mixture to the start of its laying in the formwork should not exceed 60-90 minutes.

When it is necessary to ensure the preservation of the mobility of concrete mixtures for 1.5 - 3 hours or more, then it is necessary to produce a concrete mixture with the D-5 additive with an initial cone settlement of 21 - 23 cm.

At the same time, the higher the dosage of the D-5 additive, the longer the concrete mixture will maintain its mobility and the higher the strength of the concrete will be. With an additive dosage of 3% by weight of cement, sufficiently high mobility and pumpability of concrete is ensured after three hours or more. At the same time, in the first 24 hours there may be a slight slowdown in the concrete hardening process, however, from the second day an accelerated increase in strength will begin.

During the laying process, the concrete mixture must be thoroughly vibrated, especially if increased water resistance is required. After placing the concrete in the formwork, it is important to prevent the concrete from drying out in the sun and to maintain the concrete’s own moisture content as much as possible, especially in the first 7 days of hardening, cover it with film or water it with water.

During breaks in concreting, the surface of previously laid concrete in the place of the “cold” joint must be cleaned of the cement crust with the ArmMix Cleaner material, the concrete structure must be exposed, dust and small particles must be washed off with water and the concrete must be moistened abundantly. This procedure must be done twice: 4-12 hours after laying the concrete (when the concrete has hardened), and the second time after a break in concreting, immediately before laying fresh concrete. If this condition is met, high adhesion between old and freshly laid concrete will be ensured and the required water resistance of “cold” joints will be achieved (without the use of any additional structural measures), even if the break is several months.

To improve its preparation, various additives are added. They make it possible to increase the strength of structures or increase ductility. To ensure that the solution does not lose its original qualities, special additives are used in concrete.

What are they used for?

When mixed between its fillers, binder and water, hydration occurs - chemical reaction, during which water breaks down into molecules, crystals form and the concrete hardens. The more fillers contained in the composition, the greater the number of irreversible reactions that will occur in different time. To regulate the rate of hydration Substances are added to the mixture with the help of which the structure of concrete can be changed.

Additives promote various processes:

• decrease in pour point;
• increased fluidity;
• increasing adhesive properties;
• reducing the volume of concrete and its consumption;
• prevention of crack formation;
• increased water-repellent properties;
• narrowing of pores, etc.

Besides, concrete additives are used to obtain building material with the required characteristics. Almost all components are based on chemical compounds and are produced in dry and liquid forms.

Types of additives for concrete

All additives can be divided into several groups:

• plasticizing and modifying;
• retarders and;
• gas-forming and air-entraining;
• anti-frost;
• waterproofing;
• sealing;
• pigment dyes.

Pigment dyes for concrete

Each type has its own properties, thanks to which the concrete mixture acquires certain characteristics for construction.

Modifiers

Additive modifiers are designed to improve concrete properties such as long service life, strength of structures, and resistance to low temperatures. The addition of modifying additives reduces the permeability of concrete and also increases the mobility of the solution, promoting a deeper and more uniform filling of pores and cracks.

The choice of modifier is determined by the scope of concrete application. For example, one type of modifying substance is suitable for the construction of platforms, and another type is suitable for the construction of a well or pool.

Plasticizers

This type of additive is the most popular because it can be used to achieve the fluidity and desired mobility of concrete. The effect of plasticizing substances is to reduce the adhesion force of the mixture particles and prevent its delamination.

The main advantage of plasticizers is cost-effectiveness. By adding additives, it is possible to reduce the volume of cement consumed. The second advantage is the ability to quickly fill thin-walled formwork with mortar or cast individual concrete segments (borders or tiles for garden paths).

In addition, plasticizing impurities in the composition increase the frost resistance of structures.

Plasticizer additives can vary in the degree to which they reduce liquid (water) use. The classification is as follows:

1. Weak (up to 5%).
2. Average (5%).
3. Strong (5-10%).
4. Extra strong (over 20%).

Among the disadvantages, there is a decrease in the rate of concrete hardening due to increased plasticity and mobility of the solution, therefore it is recommended to use plasticizers and hardening accelerators simultaneously.

Anti-frost

To enhance structures, an anti-freeze additive is added to the mixture at the preparation stage. Its effect is to reduce the pour point of the solution. This means that the concrete mixture can harden even at negative air temperatures.

The main advantage of antifreeze additives is the ability to construction work using a concrete composition in the cold season without preheating. In this case, the cement has time to react with water and not harden at zero air temperature.

Mobility regulators

With their help, the solution retains its plasticity in the most unfavorable conditions. Best time for the use of such substances - summer, when concrete floors are poured. Mobility regulators are added to the composition to obtain a homogeneous mass when working with floor screed.

The main feature of mobility regulators is their suitability for operation even after long-term transportation.

Additives to concrete to increase strength

These additives are catalysts for the process of gaining concrete strength and act as plasticizing compounds and hardening accelerators at the same time. They consist of organic compounds.

These additives contain chemical compounds:

• modifying the mobility and plasticity of concrete;
• increasing moisture resistance and retaining moisture inside the solution;
• stabilizers against delamination of cement-sand mixture;
• anti-hardeners and hardeners;
• air-entraining and gas-forming compounds.

They can also perform anti-corrosion and anti-frost functions.

Air-forming additives are intended to form micropores in the mixture. Since foam is formed and pores appear inside the structure, there is a need to waterproof the structure. Therefore, it is better to use air-entraining compounds together with waterproofing compounds to increase the frost resistance of concrete.

In addition, substances with an antifungal effect are produced. The presence of such additives reduces the risk of mold and fungal infections at joints exposed to frequent and forced moisture (for example, at the junction of a foundation with a blind area).

Such additives are purchased for the production of foam and gas blocks.

Anti-corrosion

When these additives are added, the solution acquires such properties of the mixture as resistance to aggressive environments that cause corrosion of the concrete structure. Additives protect structures from the destructive ability of poorly soluble compounds, prevent the washing out of microparticles of concrete hardeners, and prevent the dissolution of substances.

In addition, anti-corrosion components of the mixture are added to the composition to increase moisture resistance and increase the density of concrete.

Additives for self-compacting mixtures

Such additives are successfully used in the manufacture of structures with thin walls to increase structural strength and include plasticizers that improve the mobility of the concrete mass. With their help, the density of the composition and water resistance are increased. finished products.

Density regulators help reduce binder consumption while maintaining its quality.

Popular manufacturers and prices

Modern companies offer various additives, with the help of which you can regulate the technical parameters of the prepared food. They also make it possible to reduce the volume of binder used without reducing the strength characteristics and increase the shelf life of the mixture.

These include:

• "TechnoNIKOL";
• "Polyplast";
• "Fort";
• "Alliance";
• "Biotech".

Additives are produced in dry form in 25 kg bags or liquid, in small containers of 1.5 or 10 liters.

All additives in dry form have a shelf life of up to 12 months, in liquid form - up to 6 months from the date of manufacture.

*The average cost per unit of production is indicated.

Concrete additives (additives, premixes) today occupy a fairly large and independent branch of construction chemicals, and the demand for these materials is growing every day. Concrete is a very strong artificial material, widely used in construction to build various designs, whether it is an above-ground, underground or underwater structure. Since all structures are subject to special safety requirements, in each individual case it is necessary to ensure that concrete structures are resistant to damage and exposure to both water and various aggressive environments.

To improve its properties and physical and technical indicators for some specific tasks When preparing the solution, various additives and additives are used in concrete. They not only improve the properties cement mortars, but also simplify or reduce the cost of the technological process of preparation, and also make it possible to transport ready-mixed concrete over long distances without reducing the grade strength.

Take, for example, concreting at subzero temperatures. Since the solution contains water, concreting work in winter time become significantly more complicated. Thanks to additives that can be used in winter to lower the freezing point of water when preparing concrete or mortar on a cement base, this problem can be eliminated quite easily.

There are also types of additives that can speed up or, on the contrary, slow down the setting of the mortar, which can help when working on large construction sites.

Separately, I would like to highlight a group of reinforcing additives - fiber and fiberglass. These are materials made from various materials in the form of fibers of a certain length, usually from 3 to 60 mm, allowing in some cases (concrete floors, cement-sand screeds, platforms, blind areas, castings, etc.) to completely abandon the use of reinforcement in concrete. In other cases, in addition to significantly increasing the impact strength of concrete and bending strength, fiber fibers also take on the main risks when transporting finished products, and therefore fiber is widely used in production cellular concrete. These additives reinforce the entire matrix, preventing shrinkage microcracks from appearing.

Classification of additives in concrete and mortars

Modifiers can be grouped by the main effect of the action:

• Complex and plasticizing additives that correct the basic properties of concrete mixtures (reducing water separation, increasing mobility, preventing mixture separation)
• Accelerating or slowing down the hardening of concrete mortar
• Increasing the density and water resistance of concrete (waterproofing additives)
• Air-entraining and foaming
• Giving special properties (anti-corrosion, water-repellent additives)
• Reinforcing (steel, polypropylene, fiberglass and basalt fibers).

In order to achieve several goals simultaneously (for example, when the goal is to accelerate the development of strength and increase the mobility of the mixture), complex additives are used that include several components. At the moment, there are a huge number of different complex additives that can improve the physical and technological properties of concrete. Our catalog contains all types of the above-mentioned concrete additives.