Regulation of the properties of fireclay bricks
The most common and reliable building material remains brick. Probably, everyone knows that it is different: silicate, ceramic, fireproof. Speech in this article let's go about the chamotte version of this product.
The relatively small weight of fireclay bricks almost does not affect its resistance to high temperatures and open fire. Weight, like its size, depends on the brand. A relatively small mass, of course, positively affects the reduced load on the foundation.
Chamotte brick, GOST 390-96, has the correct geometric shape, granular base and straw-yellow color with reddish blotches. In form it can be: straight, wedge shaped, trapezoidal. When tapping, it emits a sonorous, metallic sound, and if it is broken, it will split into large pieces, and not crumble.
The principle of manufacturing fireclay bricks
Fireclay bricks, whose properties are still in demand, is used not only in industry, but also in the economy. It accumulates well and gives off heat. It is able to withstand a temperature of 1300-1500 ° C.Its strength is both a virtue and a disadvantage, because cutting such material sometimes becomes a very laborious process.
Fireclay products are produced in much smaller volumes than, for example, ceramic, respectively, its price will be higher, but also for construction work will need less.
Fireclay bricks, whose composition determines its grade, is produced by burning at high temperatures a mixture of chamotte powder and refractory clay. The firing technology must be clearly observed. If such a brick is restrained in the furnace, it will be covered with a glassy film, which will give it greater strength, but make it unsuitable for laying ovens and fireplaces.
If, on the contrary, it does not hold, then it will begin to actively absorb moisture and retain it, while losing its strength. A stove, a fireplace, a pipe or something else built of this material can easily fall apart.
Features of the use of fireclay bricks
Fireclay bricks, whose characteristics depend mainly on the content of alumina in it, not only withstand high temperatures and their oscillation, but also is resistant to alkaline and chemically aggressive environments.
Thermal conductivity of fireclay bricks depends on its porosity, and porosity - on the concentration of aluminum oxide. Thus, the porous brick will be heated longer, but it will cool down more slowly. This is called the accumulating property. But, at the same time, a large porosity will reduce its strength.
The density of fireclay bricks is approximately 1700-1900 kg / m. This value is inversely proportional to its porosity. Density determines the thermal insulation properties, its adhesion to the solution, as well as the water absorption index. Depending on how much the fireclay weighs, you can roughly determine its thermal conductivity: the lower the weight, the higher the thermal conductivity.
As fireclay bricks are used for the most important parts of the stove or fireplace, it is not even worth thinking about the use of defective or poor-quality bricks. For the laying of furnaces from such a material, a special refractory solution is required, it must be sufficiently viscous. For the construction of chimneys such a brick must have the necessary class of frost resistance. In the drawings, as a rule, it is shaded.