Deprecated: preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in /web/blog-oremonte.ru/page.php on line 13
How to concrete in frost: use of heating cable, antifreeze - Blog about repair

How to concrete in frost: use of heating cable, antifreeze

18-02-2018
Building

Is it possible to concrete in the cold? The standard answer to this question is negative. But if the situation requires the mandatory continuation of construction work, then you can always find a way out of the situation - in this article we will offer you even a few.

Photo of the foundation laid in winter

General provisions

Why concreting in frost is contraindicated? Let's look at the ingredients that make up the concrete. Cement, sand and gravel will not suffer even at very low temperatures.

But there is also water that combines all the components and makes the binder turn into stone. And it is she who is the weak link in the winter season, crystallizing at the moment when the thermometer begins to show below zero.

The transformation of water into ice is the main reason preventing winter concreting.

The frozen liquid not only ceases to perform its function of forming cement stone, but also, increasing in size, plows the concrete structure from the inside. That is, even after thawing, you will most likely get a loose shapeless mass instead of the expected monolithic structure.

At the same time, the correct statement is that a higher temperature accelerates the hardening process. This is well displayed in the following table:

Temperature, 0WITH Time to reach 70% strength, h
30 80
40 56
50 40
60 32
70 18
80 14

As you can see, if the solution is heated to eighty degrees Celsius, then further construction work can be done the very next day.

Ways of winter concreting

So, concreting during frosts is possible only if it is possible to prevent the crystallization of water. There are several methods to accomplish the task:

Antifreeze additives

Concrete antifreeze container

Вы, возможно, слышали что-то о различных модифицирующих добавках для бетона, применяющихся для улучшения качества цементных растворов. WITHреди них есть такие, которые справляются с предотвращением преждевременного замерзания воды. Можно выделить три основные группы таких модификаторов:

Group number Representatives Impact
1 Electrolytes of various levels of strength, non-electrolytes, carbamide, polyhydric alcohols. Weak, but steady acceleration of the process of formation of cement stone.
2 Calcium chloride based modifying compounds. A significant increase in the rate of hardening of concrete in combination with antifreeze protection.
3 Ferric sulfates. Fast curing with release of a large amount of thermal energy.

The use of antifreeze additives for concrete has several advantages:

  • Affordable price. The cost of their use goes below the options for the use of electrical equipment.
  • Ease of operation with their own hands. By and large, you simply add the purchased mixture to the solution.

Tip: It is recommended to increase the period of mixing concrete by adding antifreeze mixtures and a half. It is necessary that the modifier spreads over the solution as evenly as possible, and there are no zones uncovered by it. Otherwise, it will adversely affect the entire structure.

Knead the concrete in the cold should be carefully
  • Effective result. Using the described means, you can both protect the solution from freezing during the freezing period and shorten the setting period so that the cement does not have time to deteriorate.

But there is also a negative side: with the use of antifreeze additives, it is possible to concrete when the frost is not lower than -10 degrees Celsius, which is why sometimes you have to combine them with other methods of protecting concrete from freezing.

Heating cable

Laying the heating wire on reinforced rods

The instruction for implementing such a method looks like this:

  1. Before pouring the mortar, we lay a special single-core wire, fixing it to the reinforcement and formwork elements so that it will be inside the future structure.
The process of installing an electrical heating system

WITHовет: не допускайте резких перегибов кабеля, так как это может привести к перелому внутренней жилы.

  1. We bring the ends out to the unheated zone.
  2. We connect to the transformer.
Connection to transformers
  1. Fill the solution and turn on the system.

Despite the complexity of the implementation of the heating of the electric wire and considerable cost, it is most effective because:

  • WITHпокойно выдерживает морозы до -30 градусов Цельсия.
  • Heats the entire structure, not just its upper part, as is the case with the following methods.

So the water in this case will not freeze, and as a result, only cutting reinforced concrete with diamond circles will be able to cause any damage.

Diamond drilling holes in concrete, already gained its strength in the winter

The construction of the tent

Tents on an industrial building site

This method involves the installation of a tent above the concrete screed and heating it inside with heat guns.

But here it is immediately worth noting the difficulties associated with this process:

  • Great complexity.
  • High price.
  • Limited application only to horizontal surfaces.
  • Covers only the upper zone of the whole structure.

Warming by various materials

Protecting concrete from cold with improvised methods

If you cover the tie with plastic wrap, boards or other materials at hand, then you can protect it from cold to -3 degrees Celsius. Of course, it is impossible to call such an option universal, but it is perfectly combined with other methods of heating, enhancing them, and does not require significant investment of forces and finances.

Conclusion

Concreting in the winter is still possible, albeit undesirable. You just need to take care that the water in the composition of the solution does not crystallize. To do this, you can use one or several of the above methods at once.

Concrete pouring in winter

The video in this article will provide additional information. Careful preparation will allow concreting at any time of the year.