Antifrosty additives in the solution today are quite actively used in construction. Their appearance allowed the construction of buildings and structures at any time of the year without harming the quality of future structures.
The need for antifreeze additives
If you fill the solution without special additives at a low temperature, then its hardening will occur very slowly, which is due to the suspension of hydration of the cement component. When the temperature reaches -3 ° C, the liquid contained in the concrete begins to turn into ice, and the hydration process stops. When the solution thaws, all processes resume, and the structure continues to gain strength. But if ice formation occurred almost immediately after pouring, the thawing of concrete will be accompanied by the acquisition of a loose-structure monolith, this will lead to insignificant strength, in addition, the structure will not be resistant to frost.
The anti-frost additive is just used to ensure that the hardening processes occur normally in a solution flooded in winter. Antifreeze substances can lower the freezing point of the liquid, so the concrete will continue to gain strength at low temperatures.
Antifrosty additive - ammonia water
Ammonia water acts as an economically rational additive for concrete . It has more outstanding quality characteristics when compared with aqueous solutions of calcium chloride and potash. So, it demonstrates a not so impressive percentage of expansion, which makes it not very dangerous in the matter of deformation phenomena that can occur during ice formation.
The described anti-frost additive is used in the solution in such an amount that is dictated by the rules of the external air temperature. Quite often, ammonia water is chosen, and not other alternative additives, also because it does not cause corrosion processes of the reinforcement bars. The additive is not able to reduce the adhesive quality of the reinforcement with the solution, does not reduce the ability of the structure to be frost-resistant, cannot lead to efflorescence and all kinds of stains on the basis of the structures. Ammonia water slows down the period until the cement hardens, which provides a simpler laying of the mixture, which can last for a period limited to 4-7 hours.
Features of antifreeze additives
It is worth remembering, before adding anti-frost additives to the solution, that they have the ability to move and create clusters in some places, for example, in the ribs or upper layers. After that, they can acquire the structure of crystals. In order to eliminate this, you should not start work on pouring, when the temperature can vary greatly many times a day. This is especially true for conditions when the temperature goes from low to positive. This feature of weather conditions is characteristic of the autumn-spring period or winter thaws.
Some anti-frost additives in the mortar can cause the destruction of the finished concrete. This is often due to the possible crystallization of salts, which can be noted in areas where the additives are in a concentrated state. Subsequently, this may cause structural defects. Supplements that have potash as well as calcium nitrate among the ingredients are most susceptible to such phenomena. Such problems can be eliminated by carefully calculating the correspondence of the amount of additive with respect to the volume and composition of the solution, as well as external conditions.
Warnings
Some anti-frost additives in the solution (Astana is one of the cities in which you can purchase them) should not be used with concrete, which during operation will be exposed to hazardous environments. This applies to formulations that have double salts. So, sodium and calcium chlorides intensify the corrosion of steel, which becomes most likely in conditions with high humidity and the presence of oxygen in the air. But if complex compositions that have steel corrosion inhibitors are used in tandem with additives dangerous for reinforcement, the aggressiveness of the chloride component can be reduced. So, if nitrite ions are added to concrete (ratio by weight of NN: HC - 1: 1), chlorine ions are almost not dangerous for the preservation of the qualitative characteristics of the reinforcement.
Pros of anti-frost additives
By mixing anti-frost additives in a mortar for masonry or for the construction of foundations and other structures, as well as buildings and structures, you can be sure that they:
- increase the plasticity of the solution;
- make it possible to carry out construction work at low temperatures;
- increase the adhesive quality of concrete;
- increase the density of concrete;
- increase the strength of the structure after solidification;
- provide a longer service life of the concrete structure.
The cost of antifreeze additives
Anti-frost additives in the solution can have different costs, which will depend on the qualitative characteristics of the composition, its ingredients and some other factors. For example, the Russian-made Bitumast supplement can be purchased in convenient containers, the volume of which is 13.5 kg, for which the consumer will have to pay 638 rubles.
If you intend to carry out construction work in the winter, then you will certainly need anti-frost additives in the solution. Kazan (namely, Priority LLP) offers such goods from a German manufacturer for 285 rubles (10 liters).
You can choose the composition from the manufacturer that will appeal to you more in terms of price. Indeed, in the construction market today additives from different parts of the world are presented.