Dimensions of fireclay bricks

When creating furnaces and other structures that are exposed to strong heating during operation, bricks are often used. However, ordinary red brick will not work here - at high temperatures it can easily begin to melt, and when it cools, especially when it cools, it quickly deteriorates. Therefore, instead of the usual one, it is preferable to use a heat-resistant fireclay brick.

Fireclay product belongs to the category of alumina refractories. It got its name thanks to chamotte. This type of fired clay is obtained by firing until it loses its plasticity. Corundum and zirconium can be added to its composition, which give additional strength to the material. All fireclay bricks are very dense - from 1.9 to 2.1 g / cm3.

Fireclay brick does not crumble under the influence of high and low temperatures, does not react to temperature changes, as well as to changes in humidity.

Fireclay bricks have been widely used in construction for more than one decade. Therefore, at the first opportunity, a quality standard for this refractory material appeared in the USSR. It is regulated by the document GOST 8691-73, which specifies the types of fireclay bricks, their weight, density and dimensions, as well as a number of other related GOSTs.

The main varieties that are most often used in construction have the following articles: SHA-5, SHA-6 and SHA-8. By these letters and numbers, it is easy to learn about the properties of a particular brand.

In total, fireclay has six main categories. Each of them has its own letter code - ША, ШБ, ШАК, ШЛ, ШВ or ШУС. The letter "Ш" indicates that the product belongs to the category of refractory fireclay bricks.

"A" and "B" are fire resistance classes. Bricks with the letter "A" in the code can withstand up to + 1750 ° C, and class "B" up to 1400 ° C. High heat resistance is provided in these grades by a high content of aluminum oxide. In addition, they can easily tolerate high humidity.

The letter "L" in the marking indicates that the brick is lightweight.

But it is better to compare the numerical nomenclature, since there are a lot of categories in it. They reflect shape, weight and dimensions, which are easy to verify with GOST.

When choosing a building material, you should pay attention to other marks. First of all, check the references to GOST. Now factories often produce products, guided not by them, but by their own specifications, however, in this case, they must indicate this.

On bricks made according to technical specifications (TU), after the letter "Ш" there will be no additional letters that indicate the class.

Sometimes you can find other letters - this is often the personal marking of the plant. For example, BG - Bogdanovskiy plant, SL - Sukholozhskiy refractory plant.

One of the lightest and most popular brands of fireclay refractory bricks is ШБ-6. The specific weight of a single element in this category is only 2.7 kg. Bricks ША-5 and ШБ-5 have a weight of 3.4 kg, and for ША-8 and ШБ-8 - 4 kg.

The dimensions of fireclay bricks must correspond to the standard of each brand. Large discrepancies are highly undesirable, as this can complicate the use of the product and provoke curvature of the masonry.Small imperfections on the surface of the bricks can be smoothed out with a putty, however, for products that are planned to be heated very much, the thickness of the seams should be as small as possible. The ideal option is 1–2 mm.

The main grades of chamotte have the following dimensions of length, width and height (thickness), respectively:

• SHA-5: 230х114х65 mm,
• SHA-6: 230х114х40 mm,
• SHA-8: 250х124х65 mm,
• ШБ-5: 230х114х65 mm,
• ШБ-8: 250х124х65 mm,
• ШЛ-8: 230х114х65 mm.

As you can see, the differences between the sizes are very small, so it is better to check with them when choosing bricks for your furnace or other structure. At the same time, between SHA-6 and SHA-8, for example, the difference lies only in size, the rest of their qualities are absolutely the same. But such differences help to choose the optimal thickness of the brickwork.

The largest brands ShA-8 and ShB-8 are most often used in construction, when the work must be done as quickly as possible. And also the size of these bricks allows you to use the putty more economically compared to other options. And in total, there will be fewer openings between the bricks in the walls, which will increase the heat resistance of the final structure.

A separate category is fireclay wedge bricks. They differ from the standard ones in that some of their sides are not made perpendicular to each other, but with a bevel. Such bricks are used where you need to make a semicircular structure. For example, they are often used in the construction of fireplace arches.

Wedge bricks include end and edge bricks. The most popular are ShA-22, ShA-23, ShA-24, ShA-44, ShA-45 and ShA-46. They are based on standard bricks, so the dimensions along the main planes correspond to the primary brands, but additional dimensions are added due to bevels. Most brands have a bevel in the range of 1–2 cm.

For information on the sizes of chamont bricks, see the next video.