In what cases is used and how non-freezing is used for

During the construction of the house a significant part of the work can be carried out at any time of the year, regardless of weather conditions and ambient temperature. The only weak point is the performance of work associated with the use of cement-sand and concrete mortar, since for their normal solidification it is necessary that the ambient air temperature is not lower than + 5 ° C. In order not to stop construction work during the cold season, special non-freezing concrete for concrete - with your own hands added to the solution during its preparation.

Antifreeze additives for concrete mortar

To help the reader understand the features of concrete work in the winter, this article will look at one of the ways to reduce the minimum operating temperature of a liquid mortar, namely an antifreeze liquid for concrete, as the most acceptable solution to the problem.

Also here will be presented a brief instruction, which describes in detail the technology and the formulation of the preparation of winter mortar.

The difficulties of winter concreting

Concrete solution is a mixture of a binder (cement M300 - M500), fine aggregate (river or quarry sand), coarse aggregate (gravel, limestone or granite rubble) and water, which are thoroughly mixed together in a certain proportion.

After being laid in a form or formwork, over time, the cement reacts with water, which is called hydration, as a result of which it sets and gradually hardens.

The normal course of this process is possible only at positive temperatures, therefore, in case of frost in the liquid solution, the following changes may occur:

1. When the ambient air temperature drops below +5 ° C, the hydration time increases significantly.
2. A decrease in temperature below 0 ° C leads to the formation of an ice lattice in a liquid solution. The ice crystals, increasing in volume, create in the fragile solution foci of local stress, which leads to the disruption of its structure and multiple breaks in the bonds of cement particles, which have just begun to clutch between themselves.
3. In the event that the concrete has frozen, an ice crust forms around the metal parts of the structure, which pushes the mortar mass away from the elements of the steel rebar, disrupting the integrity of the reinforced concrete product.
4. The transformation of free water into ice reduces its quantity, as a result of which it will not be enough for the normal hydration of cement.

It should also be noted that all these phenomena are dangerous when the freezing of concrete occurs at an early stage of solidification, that is, when it has not yet managed to gain critical strength, which is conventionally 50% of the design strength.

Ways to combat freezing of the solution

Based on all the above, it can be concluded that the main task of concreting in the winter period is to protect the solution from freezing and to keep water in a liquid state for as long as possible.

In order for the concrete not to freeze during the curing process, there are several ways, each of which has its own advantages and disadvantages.

1. The so-called thermos effect is to use formwork for concrete from materials that have good thermal insulation properties.. In the process of preparation, the components of the solution are heated, after which it is poured into the formwork in a heated form, and then covered with insulating materials. These measures together make it possible to prevent the concrete from freezing before it reaches the critical strength value.
2. Heating of the liquid solution in the formwork is performed either by heated steam, or by passing an electric current through special electrodes. This method is very energy-intensive and requires the use of special equipment.
3. Introduction to the solution of special modifying additives allows you to speed up the hydration reaction and protects the water in its composition from freezing.

Tip! As an alternative method, it is possible to consider the construction of a closed canopy or a hut above the site of construction, which is heated by electric or diesel heat guns.

The main advantages of antifreeze

Of all the above methods, the use of liquid antifreeze additives is considered the most appropriate for individual construction.

Among the advantages of this method are the following positive qualities:

1. Due to the antifreeze properties, the freezing point of free water, which is part of the solution, is reduced.
2. Plasticizing properties reduce the thickness and increase the mobility of the finished solution without adding excess water, which contributes to a better formation of the concrete product.
3. As a rule, high-quality liquid non-freezing in concrete contains in its composition corrosion inhibitors, which prevent steel elements of the rebar from being oxidized and destroyed.
4. A balanced set of components ultimately contributes to the acceleration of a set of critical strength, and also increases the water resistance and design strength of the finished product.
5. Due to the low cost of liquid additives, the price of this method of dealing with frost is much cheaper than the others, moreover, does not require the use of bulky and energy-intensive equipment.

Tip! In structures with metal reinforcement, it is not recommended to use liquids without corrosion inhibitors due to their high corrosive activity.

Features work with antifreeze additives

In order to avoid thinking about the question when building in winter time: what to do if the concrete froze, it is enough just to use the necessary antifreeze modifying additives in a timely manner.

The technology of their use is quite simple:

1. Pour the right amount of water into a working mixer and then add non-freezing liquid in exact accordance with the instructions for use.
2. Allow the mixer to work for some time for complete mixing of the water and the modifying additive.
3. After that, load half the volume of sand into the bucket, then the entire volume of cement, and then the rest of the sand.
4. Finally, load the right amount of coarse aggregate into the mixer and leave to work until the components are fully mixed and a homogeneous mixture is obtained.

Table 1 shows the average proportions of non-freezing liquid for concrete and the speed of the set design strength.

Tip! Proper application of antifreeze additives, due to the increase in the design strength of concrete, allows the use of lower grades for the preparation of concrete mortar.

Conclusion

After reading this article, we can conclude that the use of liquid antifrosty additives will not only allow you to perform construction at any time of the year, but also significantly improve the quality of finished concrete products.

To obtain additional information on the subject of interest, it is recommended to watch the video in this article or read similar materials on this subject on our website.