What is an antifreeze additive in concrete?

When winter sets in and the weather gets cold, construction projects frequently encounter serious difficulties. Making sure that concrete can still set and harden properly in the winter is one of the main problems. Additives for antifreeze are useful in this situation.

Concrete antifreeze additives are unique compounds mixed into the concrete to aid in curing even in below-freezing temperatures. By lowering the water’s freezing point in the concrete mix, these additives let the hydration process proceed and keep the concrete from freezing before it has a chance to set.

When building concrete structures during the winter, it’s essential to use antifreeze additives to keep them strong and intact. In the absence of them, the water in the concrete mix may freeze, causing cracks and other weaknesses that could jeopardize the structure as a whole.

By lowering the need for extra heating measures, these additives not only guarantee that construction can continue throughout the winter, but they also save money and time. Because of this, they should be a part of every construction toolkit for cold weather.

Aspect	Description
Purpose	Prevents concrete from freezing in cold weather.
How it works	Lower the freezing point of water in the concrete mix.
Benefits	Allows concrete to set properly even in low temperatures.
Types	Can be chemical (like calcium chloride) or non-chemical.
Usage	Added to the concrete mix before pouring.
Considerations	Should be used according to manufacturer instructions to avoid negative effects on concrete strength.

What is concrete with antifreeze additives?

Special additives or their complexes are included in the composition of the concrete additive, which when combined with water lowers the temperature at which moisture transitions to a different form. Accelerating the setting process is another way that PMD helps concrete. In colder climates, this process takes two months or longer to gain strength. The kinetic reaction of PMD-containing concrete is accelerated.

According to GOST 21411-2008, standards do not create distinct requirements for the quality of additives; instead, the same standards apply as for other compositions. GOST 31384-2008 regulates the use of special additives in concrete to protect metal elements.

Advantages

There are several reasons why anti-frost additive is beneficial for cement mortars, including:

• the possibility of construction without downtime in winter;
• easy transportation of liquid composition at low temperatures;
• reduced need to heat concrete for setting the mixture;
• increased strength of concrete structure;
• reduced consumption of cement mortar in comparison with the standard composition.

Disadvantages

The drawbacks of PMD

• lead to the formation of salt stains on top of the material, they are extremely difficult to remove;
• the strength of the material is significantly reduced if the preparation technology is violated: add an excessive or insufficient amount of antifreeze additive to the concrete or ignore its care before setting;
• some components are toxic, they are not suitable for use in residential premises.

Types

Every concrete antifreeze additive has a unique effect on the solution’s chemical and physical characteristics.

One of three mechanisms is taken into consideration when creating modern compositions:

• antifreezes. Reduce the freezing temperature of water. Help to normalize the course of the hardening process;
• setting accelerators. Reduce the time until mineralization and acquisition of maximum strength of the composition;
• solvents. They help to dissolve concrete particles in water that were initially resistant to dissolution. In terms of the final result, the group is comparable to the effect of antifreezes, but has a lesser negative effect on the strength of concrete stone.

The most common type of additives used in concrete are antifreezes and setting accelerators. PMD is composed of both organic (urea) and inorganic (nitrates, carbonates, chlorides, sulfates, and formates) salts. Ammonia water and calcium chloride are two of the most popular materials.

Subgroups are created from the listed groups. Making the right decision is impossible without knowledge of their properties.

Plasticizers

Organic polyacrylates, melamine resin, and naphthalene sulfates serve as the building blocks of antifreeze plasticizers. They give concrete a plasticizing effect, use less water, strengthen the structure, and make it waterproof.

It is simpler to lay and level concrete after adding an antifreeze additive. Any form can be filled with the mixture and have any voids removed more easily. Moisture is retained longer in cement. PMDs lower water and energy expenses.

Strengthening

Utilized to quicken the concrete’s hardening process. Iron, calcium nitrate, calcium chloride, and aluminum sulfate are all present in the composition. Their primary goal is to shorten the solution’s hardening period. They start to work during the first three days, when the antifreeze additive is at its strongest and most effective. Work with the completed cement mortar can be done after adding strengthening additives, accounting for the increase in class strength.

Corrosion-resistant

Frost and oxidation are prevented from damaging reinforced concrete structures with the use of corrosion-resistant antifreeze additives. They increase durability and have a positive impact on the product’s service life. Concrete is more resistant to aggressive substances when such additives are used.

Mobility regulators

The cement mortar at the construction site sets quickly in warm weather, and this group of substances increases the mixture’s usability.

There are two kinds of chemical additives that they are:

1. Additives that are introduced into the mixture in small quantities (0.1–2% of the cement mass) and regulate the properties of concrete.
2. Finely ground ligatures (5–20%) – used to reduce cement consumption without changing the quality of the products.

Frost-resistant

Antifreezes that enable construction to proceed at negative thermometer readings are known as frost-resistant additives.

The marking on the product indicates its composition:

• NK – calcium nitrate;
• M – urea;
• M NK – a combination of the previous substances;
• P – calcium carbonate, reduces the curing time of the composition at -30°C;
• KHK – a mixture of calcium and hydrochloric acid. Not used for reinforced concrete structures, as it accelerates metal corrosion.

Complex

Building homes, baths, saunas, and swimming pools during the winter months necessitates the simultaneous use of multiple listed effects. Complex additives strengthen reinforced concrete structures, quicken the hardening of concrete and cement mortars, and shield metal from deterioration.

How concreting occurs?

It is important to select the appropriate PMD first. Self-made substances can have effects akin to those of manufactured goods. Ammonia water is a basic and versatile antifreeze additive. The substance stands out for being inexpensive and having no impact on the wall frame.

Its concentration is contingent upon the surrounding temperature:

Air temperature, °C	Concentration of ammonia mixing water, 5%
< -10	5
from -10 to -20	10
from -20 to -35	15
< -35	20

Add any compounds to a solution that is either cold or heated (10–20 °C). The intended purpose and the technical means of implementation should be taken into consideration when choosing the addition method.

Concrete antifreeze additives quicken the setting process; they cut the production time down to three hours for the first setting stage. Enough time is available to move the composition up to a 100-kilometer distance. It is improbable that distant locations will receive the solution.

Cement trucks can have their tanks equipped with heating systems to enhance the composition’s homogeneity and mobility.

The concrete pouring process is conducted using standard formwork, following the same methodology as custom. Modifications may be made during the composition maintenance stage, but the process varies depending on the PMD type. Certain manufacturers and varieties call for insulating the solution’s surface by wrapping it in a polyethylene film or layer of sawdust. The internal heat that is retained causes the temperature inside the concrete to rise.

When introducing a low concentration of PMD, insulation is necessary. Hardening happens subject to ambient temperature, but without extra insulation or heating if the proportion of additives is relatively high.

Application areas

When temperatures drop, concrete must actively use anti-frost additives. This is necessary in the northern regions of Russia during the winter and at other times of the year. When it’s necessary to restore concrete structures, such as roads, runways, hydraulic structures, or residential buildings, PMDs are employed.

PMD for concrete at a positive temperature between 1 and 5 °C enhances the monolithic slab’s strength and homogeneity.

Additive consumption

The use of PMD in concrete is directly influenced by the material’s intended use as well as the application rates recommended by the manufacturer or technical documentation. Antifreezes are typically added at a concentration of 10–15% of the solution’s total weight. The composition may lose some of its strength indicators and occasionally collapse entirely when the dosage is increased.

The amount of hardening accelerators used is less—between three and five percent of the cement share. When selecting a cost-effective additive, it is important to consider accelerator salts, specifically sodium formate, which has a concentration of 2-4% in concrete.

Heating the material

In anti-freeze concrete, there are two primary methods for preserving heat:

• heating with electrical equipment. The procedure is justified only when performing large-scale construction work, since the specific costs of heating increase with a decrease in the volume of concrete;
• insulation. To ensure the desired temperature, concrete is often coated with heat-insulating material. It prevents moisture evaporation and reduces heat loss. To stop evaporation, it is advantageous to cover the concrete with polyethylene film. More effective thermal insulation is provided by a layer of sawdust or a coating of dry boards.

A unique substance called an antifreeze additive is added to concrete to keep it from freezing in cold weather. Because it allows the concrete to cure properly without the risk of frost damage, this additive helps maintain the strength and durability of the concrete even in harsh winter conditions. For building projects that extend into the winter months, it’s a necessary solution to make sure the concrete sets and functions as planned in spite of the chilly weather.

Recommendations

Although using cement mortar is generally easy, there are a few things to watch out for:

• if you need to drill a hole, it is important to choose the right tool and drill. The most effective procedure is diamond drilling of holes in concrete or using a carbide drill;
• to create high-strength, loaded structures, a metal frame is required. It is important to understand how reinforcement works in concrete in order to create the most durable structure. The best technical characteristics are provided by the reinforcement frame and fiber for concrete;
• the decorative qualities of cement are quite low, most often it is treated with a finishing coating on top. There is an alternative option – grinding, it helps to eliminate protrusions and improve the appearance of the material. Several effective methods have been developed for grinding concrete;
• the thermal insulation characteristics of any monolithic foundation are inferior to porous materials. Porous concrete blocks retain heat, create less load on the foundation and are easier to lay, but are not suitable for the construction of multi-story buildings.

In construction projects, antifreeze additives in concrete are essential, particularly in cold climates. Timeliness for projects and structural integrity depend on concrete’s ability to cure and gain strength even in below-freezing temperatures, which is ensured by these additives.

Antifreeze additives keep water in the concrete mix from freezing and causing serious damage by lowering the freezing point of the water. This eliminates the need to wait for warmer weather or employ additional heating techniques, enabling construction to proceed without interruption.

For winter construction, using antifreeze additives is a sensible and effective solution. They guarantee that the concrete keeps its intended strength and qualities while also saving time and resources. Because of this, building projects can be finished on time even during inclement weather.

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