Subzero temperature of air is the main and main problem which accompanies process of winter concreting. Low temperature leads to destruction by frost of water which is part of concrete and also slows down cement hydration process. As it is correct to concrete during the winter period?
It is required to you
- - PVC film;
- - heat guns;
- - antifreeze agents;
- - transformers of big power.
1. Widespread method of concreting in cold weather is use of antifreeze agents (most of producers of concrete use this additive). Antifrosty substance is entered into concrete strictly in percentage (depending on quality class). Air temperature at which concrete is produced is not less important.
2. One of the most rational ways of concreting at subzero temperature is cement concealment. But this method is carried out at temperature fluctuating from +3 to-3. Cement has direct contact with water, at the same time it actively generates heat. To keep heat, cover fresh concrete structure with heater or film of PVC.
3. In hard frosts it is relevant to use gas or electric guns. For this purpose lay film not on concrete structure, and on timber or metal frame construction (timbering). As a result something will turn out in the form of tent or the improvised tent. Under it the heat gun is also installed. The temperature under film will be higher, the concrete fastening process will go quicker, respectively, it is possible to stop earlier heating of this design (in one-three days concrete will grab).
4. More often on large constructions the electrical curing is applied (where there is opportunity to use transformers of huge power). As in power supply networks and small substations the warming up of concrete during the winter period – rather impossible action for the private developer there is not enough power. And yet if you have such opportunity, warm up concrete electricity.
5. Even if during concreting you have not undertaken anything, and concrete has frozen, do not despair, process of set of durability will be resumed right after restoration of positive temperature (spring). Most often concreting takes place in such conditions with insignificant losses: branded durability of concrete decreases, the upper part of design is sprinkled (as the peeled-off paint).