Brick chammatory straight. Sizes of chamotte bricks of different brands, characteristics, permissible temperature, prices. Basic technical characteristics of refractory SB brick

Portland cement, which is the most common and valuable cement for use in construction, is partially different from Pozzolan cement. The product thus obtained is crushed to obtain a very thin powder, to which a certain percentage of plaster is added with the sole purpose of regulating the time spent on cementing. Cooking produces silicates and calcium aluminates, which have the property to be chemically reacting with water forming a solid stone-like mass.

The test has several chemical reactions that also require some time to complete. In general, it is estimated that after 28 days of casting, about 80% of the test chemically reacts and accepts "clutch". The mechanical properties of the cured dough are the most important characteristics, and they, like the handles, are affected by various factors, such as the mineralogical structure of cement and grace of grinding. In short, it can be said that the mechanical dough strength increases with the final grinding of the used cement with a decrease in certain limits of the amount of water used and, to a certain extent, the ripening of the test.

Also various types of aluminates and calcium silicates present in the dough and their proportions affect the specific mechanical properties Portland cement that will have different composition and processing depending on the intended use. Mixing portland cement with sand, gravel, gravel or other aggregates, solutions and concrete of various characteristics, which are installed are most often used in construction.

Very rare, never say, cements are used clean. Small amounts of pure cement are used for cementing or minor repairs. However, the use of pure cement is inappropriate for practical, technical and economic reasons.

Cements have a high retention rate during drying, which can threaten the quality of the final result, especially in large nozzles. In addition, cement is significantly more expensive than other building materials such as sand, gravel and crushed stone. Finally, mixing with other materials gives specific different properties that can be used in different situations.

Using the high strength of the cement clutch, small quantities can be mixed with a large number of inert gases without prejudice to the final mechanical strength of the product. Inert presence reduces the holding of mass during drying to minor levels, reduces the cost of construction, provides various characteristics Dough depending on the materials used. Cement mix With different inert materials is called solution or concrete. The use of inert gases from specific properties, such as foamed clay, vermiculite or perlite, as described below, it is thus the compositions obtained in such a way, heat resistance or thermal insulation, etc.

Many bricklayers are not familiar with refractory mortar. Furnaces and fireplaces are often built using Portland cement, it is possible to add small quantities of clay or refractory clayTo make cement "Fireproofs.". The portland cement problem is that it is not able to withstand serious thermal hesitation. Oddly enough, Portland cement retains its high mechanical properties to very high temperatures, but during the subsequent cooling deteriorates. After several heating and cooling cycles, everything that remained from cement made with the Portland cement is a sand that does not have anything more or less than the original binder.

The mortars no longer have the power to keep bricks together so that they end up moving or left their home, especially if a rich layer of solution was inserted between them. At this stage you want to replace the entire chimney or oven, and all you need to do is use the right refractory solution.

Fireproof refractory refractory. In fact, refractory solutions use binders that do not deteriorate when heated, but rather prone to an increase in their capture ability when exposed to high temperatures. In addition, the use of refractory solutions simplifies and speeds up the design and, therefore, cheaper.

For example, refractory solutions "pull" much faster than Portland cement. In particular, sodium silicate solutions are not hydraulic solutions, that is, they do not lead to a chemical reaction in the presence of water, such as conventional solutions, but dried under the influence of air, which allows the use of a solution layers even a few millimeters, and not to wet the bricks in advance, Without prejudice to any ability to hold, which is so fast that in a few seconds after the placement of the brick, already undertakes certain efforts to remove it.

Hydraulic refractory solutions, however, have a very fast settling time. On the market there are both pure cements and refractory solutions. For amateur use, it is recommended to use a ready solution, strictly following the manufacturer's instructions. The composition is similar to the dough used for the manufacture of bricks, binder cement in combination with a percentage of shamot. At the end of the work, any excess solution can be easily cleaned with a sponge-soaked sponge.

It should be especially mentioned by aluminum cement or "melted" cement, which is called specific production technology. Unlike portland cement, which is produced from a mixture of calcined limestone and clay, aluminum cement is obtained from a mixture of limestone and bauxite with a high content of aluminum oxide, heated to very high temperatures, until the state of liquid, cast ingot, cooled and crushed, so that it can be Bring to powder ready to use.

Aluminum cement chemicals are the same as Portland cement, but they are distinguished by a high percentage of aluminum and specific links of chemists, which calcium contained in limestone and aluminum, present in the bauxite form due to the merger, forms calcium aluminates in the form and diversity not found in general Portland cement.

The result is a hydraulic cement with exceptional characteristics: the capture is very fast, after 24 hours the hardness of the aluminum cement is higher than that of Portland cement in 28 days; Resistance to corrosion acids and water is significantly higher, which creates a lot of heat during the capture, it can also be used at different levels of the subclass, unlike Portland, which is afraid of frosts during jets, mechanical strength and abrasion exceeds, it has high refractory.

Under these conditions, these aluminates are chemically modified, released water and forming emptiness in otherwise extremely dense cement structure. Porosity and water permeability increase significantly and quickly, reducing strength and mechanical strength Concrete is proportional.

It may seem strange that cement with high refractory abilities can significantly lose its mechanical properties at such low temperatures. However, refractory and mechanical strength have different characteristics. At this temperature, the cement mass sach out, creating ceramic bonds, such as refractory brick. Mechanical resistance to compression and stretching increases again, reaching and even exceeds the original one. If he slowly cools, he retains new acquisitions.

In short, a specific product, which, if used by experienced hands, finds the use for which it can be strongly recommended. Extended clay is a natural aggregate obtained when baking a special clay, called "different colors", which has a feature to adsorb water and other materials separating gas during preparation.

For the combined action of gas pressure, which occurs inside it during heating and rotational motion, the clay liquid expands almost smoothly in the form of round balls. The material is then removed from the furnace and is exposed to air flows, which, by rapid cooling, the clay and oxidation is caused by a "clinker" surface, which leads to a porous inner core, which guarantees ease and insulation and a durable external rigid zinc coating that provides mechanical strength.

By changing the temperature, rotation and other parameters, you can control the density and granulometry of the finished product. This is non-flammable material, resistant to chemical and atmospheric substances, with thermal insulation properties. Unlike vermiculite, it has remarkable compression strength. It is used to produce light concrete, fire-resistant curtains, roofing, soles and insulating walls, land drainage and other uses in agriculture.

Vermikulite is a natural clay mineral, not very similar to the mica. It has a three-layer crystalline structure consisting of magnesium and aluminum hydroxide, which contains water. Extracted vermiculite has a very small mechanical strength, but very low thermal conductivity makes it excellent insulating material.

It is often used as inert concrete castings that should have an insulating ability. However, there are many applications, both in construction and agriculture. This is odorless material, chemically inert, non-combustible, impermeable and resistant to aging, water insoluble, sterile, unable to form volatile particles, insect-resistant and microorganisms that can absorb a large amount of liquids. It is used as a thermal and acoustic insulating material in the production of light cements in flame retardant coatings as a retainer for harmful and absorbent impurities and odors, since the filter material as a packaging material has many applications in agriculture and gardening.