How to warm up concrete in winter with your own hands: video, technology: wires and electrodes

A private developer tries to carry out construction work in the warm season, but there are exceptions when some types of work must be done in winter.

Most often, the purpose of construction in winter is to hand over the building on time.

Construction work in winter involves high labor and financial costs. For example, concrete placement requires preheating. How to heat concrete with a PNSV wire will be discussed in this article.

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Conditions for using the method

The method of heating with a PNSV wire is used for outdoor work in the cold season.

While the concrete hardens, further work is also suspended.

Even if concrete gains the required strength some time after hardening, there is a possibility that over time, the structure may crumble and collapse during further operation.

Principle of operation

Concrete warming up occurs as follows.

1. Before pouring concrete, take a cable of the required cross-section and voltage.
2. Then it is laid and poured.
3. Then the cable is connected to the network.

When exposed to high temperatures, concrete will not swell, cracks will not appear after the concrete has hardened, there is no need to be afraid of this.

The hardening process will not be stopped by negative temperatures, due to the uniform heating of the concrete, it will harden as it should, and the structure will durable and reliable.

Wire characteristics

Concrete wire has its own characteristics.

• This is a specially coated conductor.
• The protection for the wire is different and can be made of polyester or polyvinyl chloride.
• The diameter is 1.2 mm.

• Average resistance is 0.15 Ohm / m.
• The wire can be used at temperatures from -60 to +50 degrees.

How to heat the concrete with a wire

Laying the wire

Necessary conditions for work

You need to calculate in advance how much wire you will need.

Presumably, about 55 m of wire goes for 1m3.

Heating of concrete with a PNSV wire in winter is completely safe, because such a wire is made with a good insulating sheath.

Due to the strength of the core, there is almost no possibility of kinking.

In no case should you connect the wire to the network until you immerse it in the concrete mixture, because this is fraught with burnout due to the increased current.

Heating of concrete with PNSV wire is used not only for domestic purposes, but also for industrial purposes.

Calculation of a wire for heating concrete

For one cubic meter of concrete, we need about 55 m of wire. To find out how much wire you need, you need to find out how much concrete will be poured. Thus, for 20 m3 we need 1100 m.

Installation and casting of the cable

There are some complex work to be done to install the cable.

1. First, you need to clean the surface of all sorts of debris and various foreign objects, this will protect the wire from damage.

2. Then make sure that the wire is not kinked. For this, the wire is laid in a semicircle, but so that there are no empty zones.
3. The most common pattern for laying a cable is a snake.

Connecting to the mains

After all the manipulations described above, fill and connect.

To connect the cable, it is necessary to bring it to a power source, and when connecting it is recommended to use a transformer.

After you have connected the cable, it is necessary to observe safety measures:

• there should be no voltage surges,
• use a stabilizer to avoid surges.

Connect the wire in two ways: "Star" and "Triangle".

In the "Triangle" scheme, the wire cores are divided into three equal parts and the wires of each part are mated in parallel.

The sets that have formed must be connected in three nodes and connected to the three terminals of the station.

Warm-up

Before starting concrete heating, it is necessary to find out the warm-up time.

At first, the solution will be warmed up, and the temperature should not be increased by more than ten degrees.

The second step will be to raise the temperature by no more than eighty degrees.

The final stage will be the cooling of the concrete, but it is not worth lowering the temperature more than five degrees per hour.

Work after warming up

This question can be answered positively, but several nuances must be taken into account.

You can cut concrete, but you don't need to shock.

When cutting, it is better to use a diamond tool.

If you use this tool, the hole in the concrete will have smooth edges when drilling.

Also, if you cut a hole in the concrete with a diamond bit, then at the moment when the bit reaches the reinforcement you will not have to change it.

Recommendations

• Concrete heating cable can be wound around steel frame, but it is necessary to ensure its tension.

• When it is laid between the elements of the metal frame, it must be borne in mind that the wire should not touch the formwork and protrude beyond the concrete after pouring.
• The cable is installed only after the reinforcing frame has been laid.
• Also, it is not worthwhile to carry out work until the embedded parts are fenced off.
• Heating of concrete is not permissible after curing up to 50%.
• The cable should warm up the concrete from about 40 to 80 degrees.

• Concrete gains strength in about three days.
• The heating station works according to the intermittent or long-term principle.
• The distance between the wires should not be more than 15mm.
• The wires must not touch or cross.
• Special wells are made to control the temperature regime in the poured structures.

• Until the concrete is completely poured, the concrete must not be heated!
• It is better to entrust all work with concrete and electricians to specialists in order to avoid any mistakes.

The decision will only be yours. We hope our article was useful to you. Good luck