Use of fireclay bricks in construction

Brick is the most popular building material in the field of construction of residential and industrial buildings. There are many varieties of bricks, different in physical parameters, on which the area of ​​their application also depends. In this review, we will discuss brick with chamotte. But, let's start from the beginning.

Brick types

1. Ceramic bricks( the main component is clay).
2. Silicate brick( sand + clay + various additives).
3. Refractory brick( sand + clay + additives, improving the ability to resist high temperatures):

• zhele;
• refractory;
• Borovichi;
• New Moscow;
• hearth;
• chamotte.

Chamotte( alumina) bricks are made from special chamotte powder and various clays, burning billets in special furnaces at a very high temperature.

Chamotte is a fire-resistant clay that has lost chemically bound water and plasticity during firing, caking to a certain extent. This raw material is produced in shaft furnaces by roasting at 1300-1500 ° C.

Kinds of chamotte

1. Highly combustible( moisture absorption 2-10%).
2. Low-fat( moisture up to 25%).

Visual differences of fireclay bricks

1. Yellow( sand) hue. Saturated and dark color indicates that this brick is suitable for masonry stoves.
2. Grainy texture.
3. Rough surface.
4. Special marking( "Ш").

What shape can be brick fireclay?

• rectangular;
• wedge;
• trapezoidal, etc.

Advantages of fireclay bricks

1. Refractory properties. Chamotte blocks are capable of withstanding up to 1600 ° C.
2. A plane made of this material warms up quickly and holds heat longer than a similar ceramic( ie, to achieve the same effect, less fuel is needed).
3. Easy to install. Each of the 6 sides of fireclay bricks can act as the front side. For comparison, ceramic brick has only 3 such faces, which differ from others visually.
4. Does not emit harmful fumes when heated, unlike other varieties of refractory bricks.
5. Resistance to aggressive alkaline and acidic media.

Disadvantages of fireclay bricks

1. Fewer freezings-sizes, which are capable of rendering such a brick, in comparison with the ceramic analogue. To eliminate this drawback, you can use a special lacquer or liquid glass.
2. Because of the special hardening is badly cut. The pruning of this material can be made only by a Bulgarian equipped with a diamond disc.

Weight and dimensions of fireclay bricks

1. Weight = 3 kg.
2. Dimensions of the most popular types of this type of brick: 25x12x6.5cm and 23x11.4x 6.5cm.

Signs of good quality bricks

1. The correct shape and smoothness of the surface.
2. No chips, white stains, cracks, unevenness.
3. Color saturation( the darker, the better).
4. When tapping, the brick produces a sonorous sound.
5. With a strong impact does not crumble, and is divided into large pieces.

Signs of unburned bricks

• pale not expressed in color. The
• , when tapping, forms a dull sound.
• brittleness( it is painted with a chisel impact).
• is too porous structure.

With excessive firing, the brick becomes black, charred and melted to the very middle. The resulting product is called iron ore. He is very resistant to the influence of various external factors. It is advisable to choose it for laying foundations and sewer lines. But, for the construction of stoves, this brick is no longer suitable.

Where is it advisable to use such a brick?

1. Finishing of those surfaces of outdoor stoves that are in direct contact with fire - firebox, chimney, etc.
2. Masonry fireplace or oven, arranged in a house entirely made of fireclay bricks.
3. Creation of production plants for concentrating, metallurgical and chemical and other industries such as blast furnaces, boilers and fuel chambers, etc.

This building material is often preferred in the construction of a stove or fireplace, but here we must remember that the price of fireclay bricksmuch higher than the classical ceramic.

Masonry features

1. Masonry is done without pre-soaking the blocks.
2. It is necessary to pre-clean the surface from clogging with a brush.
3. The width of the joints during laying should not exceed 3 mm.

Preparation of a bonding mortar for chamotte masonry

Preparing for the beginning of the masonry, you can buy a ready-made powder( chamotte mortar) to make the binder solution, and you can make such a powder yourself by mixing refractory clay and fireclay sand. Let's consider both variants.

Mortar preparation( per 100 pieces of bricks)

What is needed?

• 40 kg of finished powder( yield - 3 buckets of finished substance);
• pure water( no additives, not salty);
• Portland cement - 6kg( 15% of the weight of dry blizzard);
• electric drill( concrete mixer).

Technology of cooking

1. In dry refractory powder, just add water. This must be done before the time when the solution becomes a creamy-like density.
2. In this case, stir the solution for at least 5 minutes with a mixer, electric drill or concrete mixer( for large volumes).
3. Leave the substance for an hour.
4. Mix again.
5. Add Portland cement to improve strength properties.
6. The solution is ready for use.

The use of a blizzard is definitely a more comfortable and simple option. However, a solution made from the main constituents with its own hand does not give such a strong shrinkage and has better strength characteristics. Therefore, it is better not to be lazy and prepare the solution yourself.

A mortar made with fireclay sand and refractory clay

What is needed?

• 1 pack of ground clay( preferably white kaolin);
• sand chamotte( chopped battle chamotte blocks);
• water( pure, no additives, not salty);
• screen( with cells 3x3mm in size).
  

  Sand chamotte

Technology of creating

1. Soak the clay so that the water covers it completely.
2. Leave for a while( from 12 hours to 2-3 days).
3. Periodically stir the substance.
4. Thoroughly clean the clay through a sieve.
5. Add sand sifted through the sieve( its mass should be twice the mass of clay).
6. Stir thoroughly.
7. Proceed to the laying.

Important!

1. If white kaolin clay is not found, replace it with Cambrian blue.
2. Pure clay almost does not smell. If there is a very strong smell, organic additives are not washed out of the clay.
3. The only permissible replacement of chamotte sand is rock sand without inclusions. Do not try to replace it with quartz analog, marble or granite chips.
4. The final solution should be so thick that it can freely slide off the trowel without sticking or staining it. It should be free of lumps and clots.

A solution made according to all the rules does not require the use of additional additives. However, if there is any doubt about the quality of the mixture, certain substances can be used to improve some of the qualities.

Additives

1. For strengthening strength properties: salt - 100-150g / bucket;cement 150 - 1/2 trowel / bucket. But, it should be understood that adding cement, you can no longer repair the masonry, and salt often leaves whitish stains.
2. To increase plasticity - liquid glass( 1-3% of the volume of the solution).

Fireclay bricks today has become indispensable, its application guarantees the safety of the masonry in specific operating conditions, improves fire safety and gives a special visual effect to home furnaces and fireplaces.