- Why does the soil freeze
- How to prepare the ground in the early stages
- “Folk” antifreeze additives
- Factory additives from the table above
- Electric heating
- How to do electric heating of brickwork with your own hands
- Frost-resistant materials
What rules for the use of building materials in winter do you need to know so as not to lose in quality? How to keep heat in grout or concrete? We will talk about these and other features of construction work in the winter in this article..
Continuity of work all year round is a necessity, first of all, for small developer companies and private craftsmen who build houses on order or for sale. Winter construction presents a problem related to the properties of materials, in particular, mortars and concrete – they do not want to freeze in the cold. Even an excavator does not take the frozen wet soil. Improper storage of building materials in winter can turn into trouble. For example, an ice-covered board, unevenly thawing in the structure, can warp it, and mineral wool insulation is completely afraid of moisture. The methods of solving these and other problems will be discussed..
Many measures for work in winter are taken during the warm season. In particular, soil preparation for winter development takes place before frost, at above-zero temperatures. The tree is prepared for winter (they begin to dry it) even earlier – in the last summer month. But first things first.
Winter development methods for unprepared moisture-saturated soil (loam, sandy loam) resemble a theater of war. It is drilled, hammered with diesel hammers, and even blown up – the natural bond is so strong.
Why does the soil freeze
It is not the solid particles of the soil that freeze, but the water that it contains. Under the influence of gravity, capillaries are formed in the medium (the so-called “capillary pump”), through which moisture enters the lower (from 40 cm) layers. Having frozen, capillaries become cold bridges. Accordingly, the higher the moisture content, the stronger it will bind in frost. Using the contradictory method, we conclude that the less moisture, the less adhesion and the more pliable the soil. This can be seen on the example of a heap of sand (clean) lying in the cold. The sand filters the water and does not retain it, so a frozen heap can be worked out with a shovel manually, and it will be loose even inside. On the other hand, trying to dig frozen clay is completely useless..
How to prepare the ground in the early stages
If in early summer it is known about the upcoming need to work on the site in the winter, and the site is swampy or has wet soil, it should be drained – dig the site with a trench. Then you can apply one of the many methods of soil strengthening..
In the case when it is necessary to prepare for winter in a short time, in the last warm days, this can be done in one of three simple ways:
- Thermal insulation layer device. Delay freezing for 2-3 months. The material can be: sawdust, mineral wool, polyurethane foam (including liquid) or special blankets. This method is the most expensive because it requires additional protection of the insulation from snow, rain and wind. The material is often used one-time.
- Plowing. The plot is plowed in two directions to a depth of 40–50 cm and harrowed by 7–10 cm. This destroys the “capillary pump” and cold bridges. Harrowing the top is necessary to create a primitive model of insulation – a material (in this case, soil) mixed with air. Such work is carried out at the end of the rainy season, possibly in the first days of frost. The plowing method is the most efficient, but requires the involvement of equipment.
- Salinization. It consists in impregnating the soil with salts or their solutions. Salt destroys the structure of hydrogen bonds and disrupts the natural properties of pure water (reduces thermal conductivity and increases heat capacity). This principle underlies the preparation of “winter” mortars and concretes. At the end of the rainy season, it is sufficient to simply fill the area with salt. Can be used in combination with plowing, even at shallow depths (motor cultivator). The method is the simplest technically, but expensive, provided that salt is purchased at a market price..
Attention! In all cases, be sure to take care of the removal of the fertile layer..
In the case when the soil is still frozen, various methods of thawing are used – from heating by a fire to steaming in hollow piles.
As mentioned above, processes in concrete are similar to those in soils. But unlike them, a chemical reaction must take place in concrete, which requires three factors: water, heat and time. That is, it must be realized in a certain environment at a given temperature at a certain time. In the summer, everything goes according to plan – the air temperature allows the reactions to take place. Frost disrupts this process, “barbarously” taking heat from the water.
In small construction, concrete walls are a rarity, but a foundation and all sorts of sides are massively made of it. This makes it possible to partially use the energy of the soil while maintaining heat. There are three ways to extend the life of liquid concrete:
- Electric heating. The most efficient and expensive way. The heating cable is woven into the reinforcement cage, after the concrete is placed, the voltage is connected. Energy consumption – about 10 kW / h per 1 m3. Requires the installation of special heating stations. Only large firms in the construction of high-rise buildings are able to provide this method..
- Shelter with a blanket. If we are talking about the foundation, located mostly underground, then the filled forms can be covered with a solid dense material such as a tarpaulin, throwing the boards over the entire area. In this case, it is enough to heat the air in the formed chamber once..
- Antifreeze additives. These are liquids based on solutions of sodium, calcium, silicon salts and additives (for plasticity and rapid shrinkage). Differ in operating temperature and can be used in combination with other methods, increasing their effectiveness.
Prices for antifreeze additives:
Name, manufacturer Substance Temperature range, ° С Release form Price, rub. NEOMID Stop Moroz, NITCAL, Norway calcium nitrate,
-5 …- 25 Bucket 1.5 kg 375 Antifreeze additive Bitumast, Russia modifier,
0 …- 15 Bottle 1 l 90 Canister 5 l 380 Canister 10L 670 “Crystallisol KMD”, “Gidrostroykomplekt”, Russia complex salt solution -5 …- 25 Spill from 50 l 105 for 1 l Antifreeze additive KBS, Russia calcium nitrate solution -5 …- 15 Canister 10 l 450 Antifreeze additive DECOSELF, Russia (Pufas technology, Germany) complex salt solution -5 …- 10 Canister 10 l 295 Praktica ICE, “Kuban-Polymer”, Krasnodar potassium nitrite solution -5 …- 20 Canister 5 l 190 “Almira PMD”, “Almira”, Russia sodium formate solution 20% -5 …- 15 Canister 5 l 190 GOOD-HIM, “Giropromstroy”, Russia sodium formate solution 25% 5 …- 15 Canister 10 l 285 Antifreeze additive “Progressol yellow”, “Progress”, Russia liquid soap,
0 …- 10 Canister 5 l 75 Pure sodium formate, “Arm-Snab”, Russia (made in China) sodium formate,
0 …- 15 Bag 50 kg 40 per 1 kg Potash К2СОЗ according to GOST 10690-73, SibEnergo, Russia (made in China) potassium carbonate technical,
-5 …- 25 Bag 50 kg 48 per 1 kg Sulphite yeast mash (SDB), “SibEnergo”, Russia (made in China) White powder – Bag 10 kg 100 per 1 kg
Masonry consists of two components – stone / brick and mortar. Unlike concrete, mortar has a long pause between production (mixing) and laying. The main load in the structure is borne by the brick (the solution only distributes it).
When properly stored (without intensive moisture), the stone itself is ready for laying. However, in the cold, it acquires additional heat capacity – the ability to absorb heat in contact with a less dense medium. This is the main factor in the rapid loss of properties of the solution. Therefore, the requirements for the solution are lower in strength, but higher in heat capacity..
There are a number of techniques that help maintain the quality of the final product when working in the winter..
“Folk” antifreeze additives
Liquid soap (10% water) is added to -5 ° C. The introduction of sodium chloride, calcium, sodium nitrate (salt, soda and saltpeter – 5–10% by weight of water) into the solution slows down the process of heat transfer. They are used at temperatures down to -15 ° C. In frost down to -25 ° C, potash (potassium carbonate) is added, which maintains the temperature, but accelerates the setting. In turn, to increase the “life span” of a solution with potash, an inhibitor of the heat exchange reaction is used – sulphite-yeast mash (from 1 to 2.5% of the mass of cement).
Factory additives from the table above
Most of the additives are suitable for mortars and concretes due to the homogeneity of the reactions taking place in them. Both receptions require high temperature water – not lower than -45 ° С.
Effective method with good voltage.
How to do electric heating of brickwork with your own hands
- In the process of laying bricks, release the tendrils of the masonry mesh by 50-70 mm (after 2-3 rows).
- Bend the antennae into a loop and pick up the bolt / nut with washers.
- Include a 3 kW BM071 type power regulator in the household network (cost about 1000 rubles).
- On each side of the row, connect the wires from BM071 so that they fall on the same net on both sides.
- Apply voltage to the regulator in minimum mode.
- Increase the voltage gradually while observing. Depending on the volume of the masonry, the result is achieved at different voltages.
Recommended seam area for heating from one regulator – up to 2 m2. Optimal placement in the masonry – two to the third seam.
Attention! Be sure to cover the heated masonry or create heat in some other way. In this case, the heating use time will be reduced several times..
The greatest effect (better qualities at lower costs) can be achieved by combining both methods – to warm the solution containing additives. In all cases, at the end of the working day, the masonry should be covered with heat-reflecting material..
The method of laying “for freezing” stands apart. A stone (brick, cinder block) is laid in a warm solution, which then simply freezes. This method was “invented” during the times of intensive construction, when the lack of quality properties of products was compensated for by mass production. Is the masonry strength low? Making the walls thicker!
The method appeared due to the unique properties of masonry mortar to completely restore the possibility of carrying out a chemical reaction after thawing. At the same time, the shrinkage characteristic of it returns, which did not manage to pass last season when the liquid mixture freezes.
Nowadays, this method can be easily applied to the urgent construction of irresponsible structures – sheds, garages, outdoor bathrooms and plugs of openings. There are several rules for freezing masonry:
- Do not dilute the frozen solution with hot water. It should be thawed and processed (mixed with fresh).
- Seal seams as quickly as possible so that there is no shrinkage during thawing.
- Use factory reinforced concrete lintels.
- Masonry height with a thickness of 1 brick – no more than 8 m, with a thickness of 1.5 bricks – up to 12 m.
- Do not carry out finishing work and installation of doors and windows until the temperature stabilizes above +5 ° C (five days in a row).
Saw and timber can be used at any temperature only if properly stored in natural humidity conditions. Water from an ice-covered board during thawing can dampen the insulation or cause unexplained dampness..
If you assemble any structure from a board of coniferous species (with low density) and begin to dry it unevenly, then it will invariably warp. This happens when “winter” houses are in a hurry to populate as early as possible. This becomes the cause of incomprehensible creaks and crackles – the tree dries. Therefore, in winter, after the construction of walls and roofs, frame houses are heated (dried) with heat guns, covering the openings with film. When the structure dries evenly, it stays smooth and rigid.
Without any special inconvenience (not counting the equipment of the master) the following objects are erected in winter:
- Steel structures. On locksmith (“cold”) joints or welding. Usually these are hangars, supermarkets, garages. Then they are sheathed with sandwich panels, also temperature-insensitive..
- Houses and cottages, pre-assembled according to the finished project. These are houses made of rounded timber or SIP panels, the material for which is prepared and stored in proper conditions. After assembly, the frame does not require intensive drying.
- Thermoblocks. Concrete walls with non-removable polystyrene foam formwork. The walls of the formwork hold the temperature until the end of the initial reaction.
In any case, winter construction entails additional costs that can be waived when time is precious. By following the rules and using the tips given above, you will be able to conduct a continuous cycle of work regardless of the season.