Fireclay artificial stone is valued for its high strength and heat resistance. Experienced builders recommend using it for laying stoves, fireplaces and chimneys. The weight of fireclay bricks depends on its type and size, they must be taken into account when drafting a future building.

Main types

The stone is made from fireclay powder and special refractory clay, which are mixed with each other in equal proportions. The resulting product has a rough, fine-grained structure of a bright yellow color, but the content of small red inclusions is also acceptable. Briquettes are characterized by low thermal conductivity, withstand high temperatures, they are not afraid of high humidity, they are environmentally friendly, strong and durable.

The weight and dimensions of fireclay bricks depend on its type. There are several classifications of products:

• According to the class of fire resistance - it happens with the marking ShA, can be used at temperatures up to 1400 ° C, and ShB - up to 1350.
• In shape - rectangular, trapezoidal and wedge-shaped, used for vaults and arches of stoves and fireplaces.
• In size - single, one and a half and thickened.

Mass of artificial stone

The weight of fireclay refractory bricks varies depending on its dimensions. Most often, for laying stoves and fireplaces, products marked ShB are used. Their mass is taken into account to evenly distribute the load on the foundation and other components of the building. Brick ShB-5 fireclay weighs 3.4 kg with dimensions of 230x114x65 mm, ShB-6 - 2.7 kg with 230x114x40 mm. An artificial stone marked ShA also has a numerical designation 5, 6 or 8, its external volumes are the same as those indicated for ShB. The mass of fireclay SHB-8 bricks is 4 kg, and the dimensions are 250x124x65 mm.

How to make the right choice

1. Check the strength of the briquettes and how the firing technologies were observed. To do this, take one copy and gently tap it with an iron object. If you have a quality product in front of you, you will hear a ringing sound, the instrument will seem to spring from it, and vibrate in your hands. In the event of a strong impact, the briquette will not crumble, but will crumble into several large pieces. Incorrectly burned and poorly dried will give a dull sound, crumble into small pieces.

2. Be sure to make sure that the selected product is stored in appropriate conditions. It should be stored in a dry and well-ventilated area on wooden pallets. During transportation, the supplier is obliged to pack it in polyethylene.

3. Choose products with an even geometric shape and a uniform shade, without chips, cracks and dents.

Related articles:

stoneguru.ru

What is fireclay brick

This material is quite simple in composition, it is based on dry fireclay powder, the content of which reaches 60%. It is obtained from kaolin (white clay), which has high refractory properties due to preliminary cleaning and firing. Pieces are crushed in order to obtain particles of various fractions used for the manufacture of mixtures, bricks, blocks.

The composition of the material also includes purified refractory clay. Additional components can be graphite and coke fillers and quartz grains of a large fraction. All substances are mixed in the right proportions, after which they are sent for molding and pressing.

The most important technological nuance is firing. The process is designed to the smallest detail, because any deviation will interfere with obtaining the desired properties. So, unburned elements do not have the necessary strength, absorb water well and quickly collapse. And burnt parts acquire excessive hardness, which makes it impossible to lay them on any solution due to low adhesion.

Brick firing is possible only in professional kilns

High-quality fireclay bricks have several features:

1. The color should be straw yellow with red patches.
2. The base is exceptionally grainy.
3. On impact, a metallic sound is heard.
4. High strength. With a slight mechanical impact, the structure of the material should not be disturbed.

Straw yellow color is considered classic for fireclay

There are also different forms of fireclay products:

• straight (standard);
• complex shaped;
• industrial;
• large block;
• laboratory.

Great attention must be paid to the choice of a suitable material, otherwise many problems may arise.

Additional elements of refractories are widely used when laying furnace chambers of complex shape.

Product pros and cons

Products have advantages and disadvantages, depending on the properties of a particular variety.

Advantages:

There are also negative points:

• If the production technology is violated, the quality and size of products change.
• The cost of production is quite high.
• For masonry, a special mortar is needed - a mortar, the layer of the mixture must be very thin.
• High strength limits cutting.

For cutting high-strength blocks, a diamond blade is used on stone

But the existing shortcomings do not reduce the demand for the product.

Types and scope

The scope of such products is quite extensive. The main areas of use depending on the properties:

1. The main purpose is the construction of the internal contour and lining of fireplaces and stoves in private construction, chimneys.
2. It is used to protect furnaces, taking into account the maximum heating up to 1700-1800 degrees.
3. Can be used for industrial convection shafts and installations.

For household stoves and fireplaces, one layer of refractory bricks in the firebox is enough

There are various types of fireclay refractory bricks, which are divided according to the method of molding, the shape of the parts and the level of porosity.

According to the molding method, the following options can be distinguished:

• hot pressed;
• thermoplastic pressed;
• fused;
• cast.

Refractory materials are divided into several types

The shape of the brick can also be different, due to the need to make different geometric facings of the stove or fireplace. There are the following options:

1. Straight. Used for flat areas.
2. Wedge. It has a bevelled side, suitable for complex shapes of fireboxes and their decoration.
3. Arched. Allows you to design semicircular sections of furnaces and make the configuration smoother.
4. Trapezoidal. It is also used for laying out the furnace and individual sections of the structure.

When laying household stoves and fireplaces, 4 forms of refractory blocks are most often used

Of great importance is the correct choice of the level of porosity. This indicator determines the ability to retain heat and the area of ​​\u200b\u200bend use. There are the following varieties:

• Very high density. The level of porosity is not more than 3%.
• High density. The indicator does not exceed 10%.
• Dense. Grain content ranges from 10 to 16%.
• Compacted. The level varies from 16 to 20%.
• Average density. Grain parameters are not lower than 20% and not higher than 30%.
• Low density (lightweight). Porosity 30–45%.
• Lightweight. The parameter ranges from 45 to 85%.
• Ultra lightweight. The graininess is very high - more than 85%.

This diversity allows you to choose the best option for a particular site.

Performance characteristics of bricks in comparison

Technical characteristics of fireclay bricks

Technical specifications:

• Fire resistance indicators - from 1100 to 1800 degrees.
• Frost resistance grade - F15-50.
• Density - 1650–1900 kg / m3.
• Porosity - from 3 to 85%.
• Strength grade - M75-250.
• Thermal conductivity coefficient - 0.6 W / m ° C.
• The specific heat capacity is different at different temperature indicators. So, at 100° it is 833 J/(kg deg), and at 1500 degrees it is 1251 J/(kg deg).
• Linear expansion (coefficient) - α, 10−6/°C: 5.3.

Fireclay bricks are equally well suited for both laying the furnace and for the construction of the furnace body.

To give certain properties to fireclay bricks, there are two main production technologies: in strict accordance with the state standard, where all characteristics have clear parameters depending on the brand and variety, or according to specifications (technical specifications) determined by each manufacturer individually. Naturally, the first option is better and therefore preferable.

Dimensions and weight of products

The weight of fireclay refractory bricks depends on the type and method of production. So, according to GOST, a standard single product will weigh from 2.8 kg to 3.7 kg. When manufactured according to specifications, the maximum weight usually does not exceed 4.5 kg.

The geometry of the product affects the size range of fireclay bricks:

1. Straight standard parts are 230 (250) mm long, 114 (124) mm wide and 65 mm high.
2. For wedge-shaped elements, the most common parameters are 230 * 114 * 65/45.
3. Trapezoidal brick is found in size 250 * 124 * 65/55.

More accurate dimensions and weight depend on the brand of product.

The classic dimensions of the fireclay block

Marking

All types of bricks made of refractory clay and fireclay powder (sand) have a certain marking, which indicates the scope of their use and production technology.

The abbreviation includes letters and numbers. The first letter "SH" means that this is a fireclay type of refractory product. Then, according to GOST, “A” should follow - the content of 30% aluminum oxide or “B” - may consist of 28% aluminum oxide, which means the fire resistance class. Elements marked "SHA" are able to withstand temperatures up to 1700 degrees, "SB" - up to 1650 degrees. If there is a number after the letter “Ш”, then the products were manufactured in accordance with the specifications.

Each type of furnace blocks is marked separately

Depending on this designation, fireclay is used for the following works:

• SHA, SHB and SHAK are universal varieties suitable for arranging fireplaces and domestic stoves.
• ShL is a light version used for lining. It has a high porosity, therefore it is not used for the furnace device.
• SHV and SHUS are suitable for steam generators and convection shafts.
• PB is recommended for domestic use, laying stoves and barbecues.

Dimensions and characteristics of the best-selling fireclay

On a note! All markings are clearly related to the dimensions, weight and fire resistance class of the material.

The most common are (L*W*H):

• SHA-5 - 230 * 114 * 65 mm;
• SHA-6 - 230 * 114 * 40 mm;
• SHA-8 - 250 * 124 * 65 mm;
• SHA-9 - 250 * 150 * 65 mm;

If there are several letters after the number, then they indicate the abbreviated name of the brick production.

otdelkagid.ru

Characteristics

Qualitative indicators characterizing fireclay bricks are strictly controlled by the state. The GOST contains indicators that reflect the weight of fireclay bricks and its dimensions, the composition of raw materials with a percentage of aluminum oxide, as well as technological properties: strength, geometric parameters, fire resistance, porosity.

The main indicators are shown in the table:

In the manufacture of products, many manufacturers are guided by their own specifications instead of the conditions prescribed by GOST. Therefore, when choosing a material, the question arises which brick to take. Indeed, according to a number of characteristics, products manufactured in accordance with GOST and according to the manufacturer's specifications very often do not coincide. In that case, it's best to purchase goods with a GOST mark, because it is better.

As for the geometric parameters, GOST specifies the size of a standard rectangular product 230x113x65 mm, and this is considered the optimal material for the construction of brick structures. But today other dimensional characteristics are also acceptable, so the market is filled with a variety of products from different manufacturers.

The mass of products also has different indicators, and varies in the range from 2.8 kg to 4.5 kg , with an allowable weight according to GOST - 3.7 kg. When purchasing, do not forget about this, because the thermal conductivity of the material depends on the mass. To keep the heat in the room, you need to choose a material with a larger mass, because a small weight increases its thermal conductivity.

From the quantitative content in the composition of the building material aluminum oxide depends on the resistance to chemicals, alkalis and high temperatures. The content of this element in the composition affects the structure of the material, making it porous . A porous brick heats up for a long time, but it also cools down longer than usual, retaining the resulting heat.

At the same time, strength decreases with increasing porosity. Therefore, it is worth choosing
material with an optimum density of 1700–1900 kg/m. Density also affects properties such as: moisture absorption, thermal insulation, adhesion to the mounting mortar and the weight of fireclay bricks.

You can determine the porosity of a brick by just holding various options in your hands.

Summing up, we can say that when choosing such a building material, production standards, dimensions, weight, aluminum oxide content and density should be taken into account.

Marking

For the convenience of classification and ease in the choice of this building material, a marking, thanks to which you can immediately determine the properties of the material. It reflects the dimensions of products, temperature properties and technical characteristics.

The most popular brands of fireclay bricks: SHA, SHB, SHAK, SHUS, SHV, PV and PB.

Using the example of a bar marked ShB 5 SL, we will decipher the data from the manufacturer.

W- a letter indicating that the product belongs to the type of fireclay aluminosilicate bricks;
B- a brick made according to the requirements of GOST, and belonging to fire resistance class B. There is also class A.

Fireclay brick of class A can withstand temperatures up to 1350 C, and class B - 1400 C.

GOST mark guarantees the compliance of the building product with the list of specified parameters: integrity, dimensional compliance, strength, operating temperature.

If there is a number in this place, without the presence of a letter after Ш, it means that the fireclay brick was produced according to the manufacturer's specifications.

The figure itself means the geometric parameters indicated in the table below. That is, our example corresponds to the dimensions of 230x114x65 mm.

SL- indicates the manufacturer of the product. SL here is the Sukholozhsk refractory plant, and BG is Bogdanovichsky.

There is a deeper classification within each brand: shape, size, thermal conductivity.

Table with common types of fireclay bricks, according to GOST 8691-73:

In addition to the standard rectangular shape of fireclay bricks, there is also trapezoidal and wedge.

Application area

Due to its resistance to temperature changes and the effects of alkalis and chemicals, fireclay bricks have a wide range of applications. It is used in industrial plants in installations that emit active chemicals during combustion: blast furnaces, boilers, fuel chambers.

The solution used to create thermal devices is also of great importance. Usually, the same ingredients are used for mixing that are used in the production of bricks. This gives the oven a high level of thermal stability.

To lay fireclay bricks of the ShB-5 or ShB-8 brand, refractory clay with crushed bricks is used. The resulting solution is called "Mertel" or "chamotte clay".

Before laying the furnace equipment, the operating temperature of the future structure should be calculated. The width of the mounting seam between fireclay bricks depends on this indicator. The higher the operating temperature, the thinner the masonry layer. Sometimes it does not exceed 1 mm. Such work requires a high level of skill from the performer, and good quality of the prepared solution.

As a result, the consumption and cost of the necessary materials increase, and you need to choose a brand of product with a higher resistance to fire.

Despite all the advantages, there are nuances that limit the use of fireclay bricks ( negative points):

• hygroscopicity- the ability to absorb moisture. This quality reduces the strength of the product when heated and increases its weight.
• Low freeze resistance. Best of all, fireclay bricks of the ShB-5, ShB-45, ShB-94 brands withstand low temperatures. Not suitable for household stoves ShB-8, because during intermittent operation, the stove, cooling down, begins to crumble.
• High product density. Such material is difficult to cut if you need to change the original dimensions.
• High cost, long warm-up time and the need to prepare a special mounting mixture.

How to distinguish marriage

Special requirements are imposed on the quality of fireclay bricks, since it depends on strength future furnace, her high temperature resistance And heat retention capacity . Therefore, it is necessary to exclude even the slightest defect of the product.

To test for strength, you need to hit it harder. A high-quality briquette will break into large pieces, and small crumbs eventually speak of marriage.

Low-quality bricks should not be used for laying furnaces. They acquire the inherent properties of absorbing and retaining moisture. Such material loses three-quarters of its useful qualities, unlike dry.

pechnoedelo.com

One of the types of refractory bricks is fireclay bricks. It got its name from the main component that is part of it (special fire-resistant clay, popularly referred to as chamotte). The mass fraction of chamotte in the material is 70%, the remaining 30% are coke or graphite powders, which are used as special additives. Additives are necessary to create a dense structure of the material - cracks do not occur during firing. Unlike ordinary red, the weight of fireclay bricks practically does not change, since it is all solid.

The material in question is used in the porcelain industry, metallurgy, and glass production. The vaults of furnaces are made of such bricks, in which fuel (oil, gas) burns at very high temperatures. As we can see, our material is used in the most critical places of blast furnaces, so its quality must be strictly controlled, the use of low-quality bricks will lead to premature destruction of structures laid out of it. The seams between fireclay bricks should be minimal; special refractory clay, which is the raw material for the manufacture of the material, serves as a mortar.

The weight of fireclay bricks is small - only 3.4 kilograms, although it depends on the size and brand. The main size of fireclay bricks is 230 × 113 × 65 millimeters (it is its weight that is indicated). According to the standards, this material should have a yellow color with reddish speckles, accurate dimensions and a granular base. Depending on the purpose, it can be straight with the dimensions indicated above, wedge-shaped and trapezoidal. If you knock on it, you can hear a ringing sound, similar to the sound that metal makes. When broken, the material breaks into pieces; a properly made brick should not crumble.

Building materials should be used only with strict consideration of the load created on the base. That is why the weight of fireclay bricks should be carefully controlled. In addition, the organization of transportation of products also depends on this.

Peculiarities

SHA-8 and SHA-5 are the two most commonly used fireclay bricks. They are obtained by firing a clay mixture of a certain shape with significant heating. For the production of the product, a combination of kaolinite with other minerals is used. The technology implies that a certain amount of aluminum and silicon oxides should be in the finished composition. The two brands of fireclay bricks mentioned above are widely used for:

• installation of stoves and fireplaces;
• construction of chimneys;
• lining of melting furnaces at metallurgical plants.

Choosing the composition of refractory bricks, technologists have learned to influence not only its thermal stability. Differences in chemical composition cause differences in density (specific gravity). Yes, 1 pc. fireclay brick category ShA-5 weighs 3.4 kg. At the same time, its linear dimensions are strictly prescribed in state standards and amount to 230x114x65 mm. In accordance with GOST 390, a brick with a size of 250x120x65 mm must have a mass of 4 kg.

Standard fireclay products

GOST 390-96 also prescribes the mass of bricks laid on 1 pallet. It can vary from 1350 to 1600 kg. This implies laying 385-400 pieces of finished products. Mass of one cube. m of refractory bricks is from 1745 to 2050 kg. Regardless of the total gravity of 1 cu. m should include exactly 513 pieces.

Characteristics by brand

When choosing fireclay bricks, there is no need to calculate the mass of products using complex formulas. It is enough to know the specific technical brand of the finished product. So, a lightweight brick of category SB 5 should weigh 3.5 kg. It is used to decorate stoves, barbecues, make fireplaces and barbecues. Fireclay category ShA 5 has a mass of 3.4 kg. It is intended for individual residential construction.

Blocks ША 5 and ШБ 5 should have the same size - 230x114x65 mm. ShA 6 blocks, designed for laying out thermal and heating equipment, are also produced in standard dimensions - 230x114x40 mm. At the same time, the mass of such a product is 3.4 kg. The heaviest products are SHA 8. They are needed for the formation of internal masonry in heating furnaces and smoke ducts.

Calculation example

Let it be planned to build a furnace with a height of 2400 mm (with a base of 24 bricks). Each row has a height of 70 mm, and 300 mm are subtracted from the planned height for “cutting”. In total, 30 rows of masonry remain, and after multiplying by 2/3 (the usual proportion in the construction of "Dutch women"), only 20 rows will remain. The result is 480 bricks (plus 50 for "cutting").

If you order fireclay brick SHB-5 straight, then 1 pallet will contain 385 blocks with a total weight of 1309 kg. The total need in this case is 530 bricks with a total mass of 1802 kg. We can conclude: it is required to use 1.37 pallets of building blocks. You can bring them in a Gazelle-type car, but the car will be overloaded.

If you order straight fireclay SHB-8, 1 pallet will contain 297 blocks with a total weight of 1188 kg. The weight of a single product will be 4 kg. Thus, 530 pieces will weigh 2120 kg. Therefore, you will have to order a full-fledged truck to deliver a batch of fireclay bricks to the site. Of course, in reality, the size of the stoves and the number of blocks used for masonry change, it is also worth considering the chimney, but the general principle of counting remains unchanged.

You will learn more about refractory fireclay bricks from the video.

Those who have already purchased building bricks in order to build a structure from it with their own hands (a house, a garage, a fence) have an idea about the classification of this building material (silicate, ceramic). They know what, for example, a double sand-lime brick M 150 is according to standards.

Photo: the most popular refractory material is fireclay

They can say that since it is double, then its geometric dimensions are 250 mm x 120 mm x 138 mm. And the brand - "M 150" is its strength indicator and indicates that this silicate building material can withstand a load of 150 kg per 1 cm2.

Standards, regulatory documents

Anyone who is interested in more complete information on the topic, standards on refractory materials used by man in construction (laying stoves, fireplaces) today, can familiarize themselves with the following regulatory documents:

• GOST 8691 - 73 "Refractory products for general purposes".
• GOST 24704 - 81 "Refractory corundum and high alumina products".
• GOST 390 - 96 "Refractory fireclay and semi-acid products of general purpose and mass production."
• GOST 24704 - 94 "Refractory corundum and high alumina products".
• GOST 4157 - 79 "Dinas refractory products".
• GOST 5040 - 96 "Refractory and highly refractory lightweight heat-insulating products."
• GOST 21436 - 75 "Refractory and highly refractory products for lining rotary kilns".
• GOST 6137 - 97 "Refractory aluminosilicate mortars".
• GOST 969 - 91 "Aluminous and high aluminous cements".

Refractory bricks

Ordinary building bricks, depending on the raw materials used in its production, are divided into:

1. Ceramic- which is made of clay.
2. Silicate- it uses a mixture of sand and lime, other additives.

But, these products of brick production can not be used everywhere. For example, with high-temperature technologies (up to 1800 degrees C) in the metallurgical industry, in glass-making (glass-making) industries, the same ordinary clay brick (in the common people, “red”) will not withstand high temperatures for a long time.

With strong heat and prolonged exposure to high temperature, it will begin to melt, and then, as it cools, it will crumble. Although, as a masonry and finishing material, it is widely used in indoor fireplaces and stoves in baths, saunas, residential areas, where the temperature is not higher than 800 degrees C.

Types of fire-resistant building materials

In furnaces where glass is blown, porcelain is fired, in blast furnaces where steel is smelted, a more resistant, fire-resistant material is used in the furnace core of hearths. Refractory bricks according to GOST 8691 - 73 withstand heat with a temperature of more than 1000 degrees C.

Refractories are produced with different properties and characteristics for different applications.

Fire-resistant material according to its physics - chemical composition, production methods and methods, temperature range is divided into four classes:

1. Aluminous.

Composition and applications of refractories

1. quartz brick- consists of quartz (sandstone), with small additions of clay. As a result of firing, it acquires a cavity-free, full-bodied structure. In furnaces it is used in places where it has contact only with an open flame (for example, reflective vaults in fireboxes of a fireplace, stove). Keeps heat well.

Important to remember! Quartz refractories should not be in contact with alkalis, lime, iron oxides, which destroy it.

1. - in a simplified form, it is compressed graphite or coke. It has the highest characteristics in terms of strength, fire resistance. It is used in highly specialized areas of construction (for example, in the construction of blast furnace structures).

1. - includes in its composition a lime-magnesian mass, which allows the use of this refractory for the production of Bessemer steel from phosphorus ores.

1. aluminous- from its very name it is clear that in its basis clay makes up most of the structural component (about 70%). Therefore, it is better (in contrast to quartz refractories) resists the destructive action of alkalis (lime). Easily tolerates rapid temperature changes.

It is easy to manufacture, its price is lower than other flame retardant materials. It is widely used in the cores of furnaces, where the temperature is not higher than 1300 degrees C. Brick of this grade is also called "chamotte". It is marked with the letter "W", and the numbers following it carry information about its size.

The nature of the heat treatment

In the production of fireclay material, according to the processing method, products are distinguished:

• unfired;
• burnt;
• fused cast.

Designation, shapes and sizes of fireclay products (GOST 390-96, GOST 8691-73)

The size of the refractory brick and its shape can be different. According to GOST alone, there can be more than a hundred such standard sizes.

Therefore, we present only the most used products in private furnace construction. The rest can be found in the standards themselves.

The brand of building material depends on the maximum temperature of its use during operation.

Table: Limiting temperatures for the use of fireclay products

Depending on the physical and chemical composition, the temperature of use, general-purpose fireclay refractories are divided into grades ShA, ShB, their serial number (1 - 109) depends on the shape and size. These brands are most widely used in private stove and fireplace construction.

For information! Fireclay refractories are also produced in other grades, fireclay ladle bricks ShKU, fireclay blast-furnace bricks for ShPD hearths and others.

In its form, fireclay bricks can be - straight, wedge rib, wedge end, trapezoidal, suspended and shaped. Here are tables of standard sizes, shapes of some brands of fire-resistant ideas widely used in laying stoves and fireplaces.

Table: Sizes and shapes of fireclay bricks for general purposes (grades ША, ШБ)

Designation, brand	Dimensions, mm
	230 x 114 x 65
	230 x 114 x 40	straight (bream)
	250 x 124 x 65
	300 x 150 x 65
	230 x 114 x 65/55	end wedge
	230 x 114 x 65/45	end wedge
	250 x 114 x 65/55	end wedge
	230 x 114 x 65/55	rib wedge
	230 x 114 x 65/45	rib wedge
	300 x 150 x 65/55 (65/45)	end wedge
	250 x 114 x 65/55	rib wedge
	230 x 114 x 65
	230 x 114 x 40
	250 x 124 x 65
	300 x 150 x 65	Tables: Straight fireclay Thus, fireclay products for standardization are divided into: wedge or straight (normal sizes), large or small formats; shaped large-block, especially complex, complex, simple; special fireclay products for industrial, laboratory purposes. Weight characteristics of refractory (chamotte) brick GOST 390 - 96 The weight of a refractory brick depends on the raw materials from which it is made, on its shape and size. How much does a refractory brick made of fireclay of the most popular brand (ША, ШБ), and its packaging (cages) without taking into account the weight of the pallet 30 - 40 (kg), look in the table below It will be interesting to look at the video in this article, how and with what you can make a figured fireclay brick with your own hands at the link: conclusions It will be easier with the selection of shapes and sizes of bricks if you purchase a ready-made ordered layout for standardized products. Then there will be no difficulty in processing the solid chamotte material with a diamond tool for the desired shape.

Chamotte brick is an excellent refractory building material. Its natural base consists of white refractory clay (kaolin), which, thanks to feldspars in its composition, has a fine dispersed structure. Therefore, the use of fireclay bricks is so common in the construction of fuel chambers, chimneys, stoves, fireplaces and other buildings that can often come into contact with flames and temperature changes. After all, such a brick can withstand the temperature of fire in furnaces of 1200 degrees.

Fireclay bricks are used for the construction of stoves and fireplaces, because they can withstand temperatures up to 1200 degrees.

In the industrial production of refractory bricks, powdered kaolin and refractory clay undergo a firing process until their elastic properties are completely lost. Sometimes coarse quartz sand, graphite or coconut powder can be added to the brick. The technology for the production of fireclay bricks must be observed correctly, otherwise, when it is overexposed, the properties will gain even greater strength, but the overexposed brick will become unsuitable for laying chimneys. If it is underbaked, then laying from such a brick will become impossible due to its loose structure.

Types and sizes of fireclay bricks.

During the firing process, kaolin white clay retains its natural white color up to a temperature of 1200 degrees. Above 1300 degrees, it blushes, then, with an increase in temperature, it acquires a brownish tint and a granular basis. This color is considered acquired during production, it will be stable during further use of fireclay bricks.

With the appearance of brown color, the shape of the product may also change. At the exit, it has the correct geometry of the bar, and due to its low weight, it does not significantly affect the load of the foundation.

General properties of fireclay bricks:

1. Release according to GOST 390-96, the specific gravity of one brick bar is from 3.4 to 4 kg.
2. It has the shape of a rectangle or a wedge-shaped and trapezoidal bar.
3. Durable, does not crumble when broken, but only breaks into large pieces.
4. The strength is 1700-1900 kg/m.
5. Resistant to open fire, able to withstand up to 1500 degrees of surface heating.
6. Great for holding and dissipating heat.

Table of properties of fireclay bricks.

Due to its ideal physical qualities, refractory bricks have a high cost. However, its masonry does not always require a huge number of units.

The weight of fireclay products may vary. It depends on the brands of the product. At modern construction enterprises, two grades of refractory bricks are produced: ShA and ShB. The thermal conductivity of the bricks depends on the weight: it will be higher with less weight, and, accordingly, the absorption of moisture and adhesion with the mortar will be better.

When laying chimney buildings using fireclay bricks, the use of an appropriate viscous mortar with a high degree of frost resistance is required.

Therefore, the involvement of professional stove-makers is necessary.

The resistance of fireclay bricks to strong heat and sudden temperature fluctuations is provided by a special production technology. It is used in the construction of industrial furnaces, fireplace chimneys. This stone is light yellow in color, with a porous structure and high thermal conductivity. Fireclay powder (refractory clay) with the addition of graphite and coke is fired in a kiln at temperatures up to 1500 C. If it is burned through, a vitreous film forms on the brick. Such a product has increased strength, but loses refractory properties. If the brick is underexposed, it will attract moisture and quickly crack.

Varieties and weight of fireclay bricks.

They produce rectangular, wedge-shaped and shaped. Depending on the size, ShB (SHA) -5,6,8 is marked. The first letter Ш indicates directly the presence in the composition fireclay. The second letter indicates the maximum application temperature in accordance with GOST 390-96: A - 1400 degrees, B - 1350. If the product does not contain a second letter, this indicates that it is manufactured according to specifications. The number indicates the aspect ratio.

Unlike ordinary ceramic bricks, refractory bricks are denser, and therefore heavy. Fireclay brick SHA-5 with dimensions of 230x114x65 mm weighs 3.5 kg; SHA-6 - 230x114x40 mm weighs 2.8 kg, SHA-8 250x124x65 mm - 4.3 kg. Bricks marked ShB are slightly lighter than ShA. ShB-5 with dimensions 230x114x65 mm, weighs 3.4 kg; SHA-6 - 230x114x40 mm weighs 2.7 kg, SHA-8 250x124x65 mm - 4 kg.

Signs of high-quality fireclay bricks.

To check compliance with firing, you need to hit the brick with a metal object. The sound from the impact should be sonorous, and the brick should spring slightly. After a strong blow, the briquette will break into several large pieces. A poorly dried or burnt product will give a dull sound and crumble into small pieces. Improper storage can reduce product quality. Bricks should be stored in a well-ventilated, dry area, stacked on pallets. Chips, cracks, white spots are not allowed on bricks. The color should be uniform, light yellow with small patches.