Anti-frost additives in mortar today are quite actively used in construction. Their appearance made it possible to erect buildings and structures at any time of the year without harming the quality of future structures.
Need to use antifreeze additives
If you pour the solution without special additives at a low temperature, then its hardening will occur very slowly, due to the suspension of the 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 are resumed, and the structure continues to gain strength. But if the formation of ice occurred almost immediately after pouring, the thawing of the concrete will be accompanied by the acquisition of a monolith of a loose structure, 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 the solution poured in the winter. Anti-freeze agents are able to lower the freezing point of the liquid, so the concrete will continue to gain strength at lower temperatures.
Anti-frost 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 shows a not so impressive percentage of expansion, which makes it not very dangerous in terms of deformation phenomena that can occur during the formation of ice.
The described anti-frost additive is used in the solution in such an amount that is dictated by the rules of external air temperature. Quite often, ammonia water is chosen over other alternative additives also because it does not cause corrosion of reinforcement bars. The additive is not able to reduce the adhesive qualities of reinforcement with mortar, does not reduce the ability of the structure to frost resistance, and cannot lead to the appearance of efflorescence and all kinds of stains on the base of the structure. Ammonia water slows down the time until the cements harden, which makes it easier to lay the mixture, which can last for a period limited to 4-7 hours.
Features of antifreeze additives
It is worth remembering before adding antifreeze additives to the solution that they have the ability to move and create clusters insome places, such as in the ribs or upper layers. After that, they can acquire the structure of crystals. In order to exclude this, you should not start pouring work when the temperature can change greatly many times during the day. This is especially true for conditions when the temperature changes from low to positive. This feature of weather conditions is typical for the autumn-spring period or winter thaws.
Some antifreeze additives in the mortar can cause the destruction of the finished concrete. This is often due to the possible crystallization of s alts, which can be noted in areas where additives have been found to be in a concentrated state. Subsequently, this can lead to the appearance of design defects. The most susceptible to such phenomena are additives that have potash and calcium nitrate among the ingredients. You can eliminate such problems by carefully calculating the correspondence of the amount of additive in relation to the volume and composition of the solution, as well as external conditions.
Cautions
Some antifreeze additives in the mortar (Astana is one of the cities where they can be purchased) should not be used with concrete that will be exposed to hazardous environments during operation. This applies to formulations that have double s alts. 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 used in tandem with additives hazardous to reinforcementcomplex compositions that have steel corrosion inhibitors, then the aggressiveness of the chloride component can be reduced. So, if nitrite ions are added to concrete (the mass ratio HH:XK is 1:1), chloride ions are almost not dangerous for the preservation of the quality characteristics of reinforcement.
Pros of antifreeze additives
By mixing anti-frost additives into 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;
- enable construction work at low temperatures;
- increase the adhesive qualities of concrete;
- increase the density of concrete;
- increase the strength of the structure after curing;
- provide a longer life for the concrete structure.
Cost of antifreeze additives
Anti-frost additives in the solution may have different costs, which will depend on the quality characteristics of the composition, its ingredients and some other factors. For example, the Russian-made Bitumast additive can be purchased in a convenient container, 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 Prioritet LLP) offers such a product from a German manufacturer for 285 rubles (10 l).
You can choose the composition frommanufacturer, which is more to your liking in terms of price. After all, additives from different parts of the world are presented on the construction market today.
