How and from what are bricks made for building houses? What is brick made from - a building material of all times and peoples. What and how is brick made from?

Brick of any kind in all reference books and dictionaries is defined as an artificial stone in the shape of a bar. There are several types of this building material, depending on what the bricks are made from and what production method is used.

Based on these characteristics, two main groups can be distinguished:

Ceramic

This is a classic red brick made of baked clay or a mixture of several types of clay.

Silicate

Made in an autoclave from sand and lime, the color depends on the additives. White brick can be given any color, incl. red, but this will not give it the right to be called red - it will remain silicate red.

Types and quality of bricks

The scope of application of this material is very wide. Red brick is used to build load-bearing and self-supporting walls and partitions in buildings of various heights; it is used to fill voids in concrete structures, lay foundations, internal parts of furnaces, etc.

Building brick is called ordinary brick, but its front (facing) appearance is more valued. After firing at high temperatures, the material is durable and beautiful, and is widely used for cladding the external walls of buildings and plinths, restoration work and for interior design.

Properties of ceramic bricks:

Strength and durability.
Frost and moisture resistance.
Reliable sound insulation.
Hydrophobic and quick drying.
Environmental friendliness. The natural composition of bricks and time-tested technology guarantee the safe stay of people in brick walls.
High density (with manual molding reaches 2000 kg/m³).

Disadvantages include high cost, which is explained by the complexity of the technology. This material is very durable; houses made from it last hundreds of years. If you want to build a quality building, you should not try to make bricks yourself – It is impossible to ensure a sufficient firing temperature in artisanal conditions.

For cladding, you should buy material from the same batch, otherwise the color may differ.

Types of fired bricks

Private requires plastering. Often, a pressed pattern is made on its side for adhesion to the solution.
The front has two smooth surfaces; they also produce textured and shaped types. There are many voids inside to increase thermal insulation.
Stove and fireclay are made from refractory clay. The material is sand-colored and grainy.

When buying a brick, it is important to understand its purpose. Ordinary brick is much cheaper than face brick and there is no point in overpaying for the construction of walls.

Basic composition and properties of clay

The useful properties of the material directly depend on what the brick is made of and how accurately the technology is followed. A high-quality product can be obtained by supplying clay with a constant composition and uniform production operation.

The facial variety is made from fine clay. There are few rich deposits with a uniform mineral composition left. In most cases, mining is complicated by multi-layers of clays of different compositions. The layers are cut off with an excavator, the clay is crushed and mixed until an average composition is obtained. This is necessary for uniform drying and firing, since clay of different composition requires individual thermal and time processing conditions.

Typically, an enterprise works with raw materials from one deposit, so the right technology allows them to obtain a high-quality product for many years. When exploring and developing new deposits, the quality and quantity of clay is analyzed. The best red brick is obtained if the clay composition does not require additives. Typically, clay is suitable and cannot be used to produce other ceramic products.

When water is added, the mineral mass becomes plastic, and after drying it retains its shape. After firing, the clay hardens and becomes very durable.

For the production of red brick, raw materials are suitable, which include:

Kaolinite
Illit
Montmorillonite
Quartz

Important properties of clay for making bricks:

Plastic. The clay should not collapse when kneaded and retain its shape. Plasticity can be high, medium, moderate and low. Non-plastic clays are also found.
Bonding ability. The raw material retains its plasticity after adding additives. It varies as a percentage of the amount of sand and can be in the range from 20 to 80%.
Shrinkage. Changes in size after drying and during firing.
Caking ability. The property of hardening when heated. Low-temperature clay is sintered at temperatures up to 1100 ° C, medium-temperature clay - 1100-1300 ° C, high-temperature clay - more than 1300 ° C.
Fire resistance. When heated, the raw material should not melt. The highest fire resistance is found in pure, highly plastic kaolinite clays, from which porcelain is made. The facing type is made from refractory raw materials with a small amount of impurities. For ordinary bricks, a fusible type is sufficient.

Supplements

Without additives it is impossible to achieve high quality material. The technologist who draws up the recipe and knows how to make brick according to GOST, provides ways to improve the quality of the raw material.

The following additives are used:

Slag, sand, ash.

Added to thin the raw material, facilitate formation and reduce shrinkage.

Sawdust, coal and peat powder

Organics are added to reduce density. After the additives burn out, they leave pores.

Iron ore, sandstone

Special additives for regulating the firing temperature.

Ulphite-alcohol stillage

Makes molding easier.

Metal oxides

Gives color.

The technologist’s task is to select the optimal composition of raw materials, molding, drying and firing modes.

Color

You can achieve the desired color not only with the help of additives. In most cases, it all depends on the mineral composition of the clay, which is redder after firing. This type of clay is called red-burning clay.

Quite rarely, white, yellow and apricot-colored ceramic bricks are made from white-burning clay.

The brown color is obtained after adding pigments.

Naturally, the material for production DIY bricks is clay. There are many options for obtaining clay, the main thing is to find it in sufficient quantities. You can try visiting quarries in the area, or it may be right on your property. But, it is worth considering the composition and quality of the clay, not every type and type of clay is suitable - we advise you to check whether it is suitable in quality and what its fat content is.

For determining the fat content of clay There are several ways, you can find them below.

Take some clay, about half a liter. Gradually we begin to pour and mix water into the clay. We continue until the clay absorbs water and begins to stick to our hands. Next, you need to give the mass the shape of a ball (3-4 cm in diameter) and a flat cake (about 10 cm in size), and leave to dry for several days.

After two or three days, it is necessary to inspect the figures. The presence of cracks indicates that it is necessary to add sand to the clay, because... she's too fat. If there are no cracks, a strength test must be carried out. To do this, you need to throw the ball from a height of about a meter. If the ball scatters into pieces, then the clay is thin and not suitable for making bricks. Clay with a higher fat content should be added to the existing raw materials. If the Ball remains unharmed, then brick production can begin.

It should be remembered that it is necessary to mix clay or sand in small portions, and control the quality of the raw materials after each batch. This will allow you to find the optimal proportion and avoid mistakes.

DIY mold for making bricks.

Do-it-yourself raw (unfired brick) made from high-quality raw materials, in compliance with all norms and rules, practically corresponds in properties and quality to its red (burnt) counterpart, well known to everyone. Raw material can be used in the construction of small utility buildings, such as sheds and bathhouses.

Since, in this situation, there is no need to organize continuous production, there is no need to purchase or assemble a forming press yourself.

To start production, you need a simple form. You can make it yourself, from available materials: two sheets of plywood and thin boards, 20-25 mm thick. For greater productivity and speed, it is advisable to prepare several forms. These forms can easily replace an industrial press, which will allow us to get high-quality bricks at the output.

The size of the form can be any, depending on desire, but it is advisable to build cells of a standard size - 250x120x65mm. Sometimes, during the production process, special voids are formed in bricks, designed to improve the adhesion of the surface of the product to the mortar. This is why the protrusions are made in the top and bottom covers. All parts of the mold are attached to each other with 50-60 mm nails, only the top cover is not fixed with nails, which allows you to remove it to fill the mold and remove the formed brick from it.

If you need to improve the quality of finished bricks, you can make a special molding press, but this is a broad topic for a separate article.

Making bricks with your own hands.

Forming adobe (brick) with your own hands proceeds as follows: moisten the mold from the inside with water, sprinkle with a little fine dust and cement, this will make it easier to remove homemade bricks from the cells of the mold. Next, fill the molds with the clay mixture and shake to better fill the corners. If there is more clay than necessary, the excess should be carefully removed with a construction trowel or a suitable metal plate. Cover with a removable lid on top and leave for some time.

To remove the brick, you need to remove the lid and turn the mold over.

The next stage is drying. It must be taken seriously, because this is the most important stage. Everything here is a little more complicated than it might seem at first glance. After shrinkage, the size of the brick can be about 85 percent of the initial dimensions.

It is recommended to use shelving with a canopy; in such conditions, the bricks will be protected from direct sunlight, rain, and the air circulation will not be impaired. The drying process can take approximately 6 to 15 days, depending on the temperature and humidity. The higher the temperature and drier the air, the less time it will take to dry.

As a result of this stage we get raw brick.

In cases where you still need to create a fired brick, then, if desired, you can carry out the firing yourself. Of course, this stage is very difficult to complete and requires a lot of time and effort. You should not count on a large production volume. This process makes sense only for a small number of bricks - about fifty. Making more is not at all rational.

Firing bricks with your own hands.

The kiln can be made independently; a metal barrel with a volume of about 200-250 liters is ideal for this purpose.

It is necessary to prepare a hole in the ground for the fire, approximately half a meter deep. We cut out the bottom of the barrel and place it on legs, 20 cm high, on the fire. This will allow you to monitor the fire and also adjust the temperature for more even heating.

The next step is to fill the barrel with bricks, leaving small gaps. To prevent cold air from entering the barrel, it is closed with a lid. We advise you to do the following: you can easily construct a lid from a cut-out bottom, attaching handles to it for greater convenience.

The firing process itself takes, on average, about 20 hours. You should prepare a sufficient amount of fuel, and it’s better to even make a reserve, because the fire will have to be maintained all this time. By the time the firing is completed, the fire of the fire is gradually reduced. Next, the barrel needs to cool down on its own; opening the lid to improve air circulation, or using any artificial cooling method is prohibited! After about 4-5 hours, the barrel and its contents will cool down sufficiently. Now you can open the lid and start removing the finished baked bricks.

To control the quality of the finished product, we suggest doing the following: split the brick with a hammer. Well-burnt brick has a uniform color and structure over the entire fracture area. If a broken brick is immersed in water, then after some time in water the color and structure of the brick should remain uniform over the entire area of the fracture.

In case the quality test handmade bricks, passed perfectly, congratulations, you were able to make a brick with your own hands!

Brick is one of the most ancient building materials, known to the first civilizations in history, Sumer, and even earlier. But for many people today it remains a mystery - what is brick made of? In our article we will open it by filling this gap in your knowledge.

Additionally, you can watch the video in this article about brick production:

What types of bricks are there?

The two most common types of bricks are fired ceramic and silicate. The latter, has a less ancient history, is distinguished by slightly worse moisture resistance and some other characteristics, but its price is lower. In our article we will give the greatest attention to ceramic bricks, since they are produced in large quantities compared to other types.

In addition, there is adobe - a brick made of unfired clay. It began to be used in construction even earlier than ceramic, but was almost forgotten due to its low strength and almost zero moisture resistance.

Houses were built from it only in the southern regions, since the material perfectly retains coolness and stabilizes indoor humidity. Now, due to the fact that adobe is more environmentally friendly than most other materials, it is again beginning to be used more and more widely.

Why know what brick is made of?

As we already said at the beginning of the article, first of all, you need to know what a brick is made of to broaden your horizons.

But this is only one reason to learn the technology of making bricks. There are two more:

knowing how and what brick is made from, it is easier to choose the right material for construction and use it correctly;
you might want to make your own brick.

If the first argument is undeniable, then the second may raise doubts, because it is easier and often cheaper to purchase ready-made material.

But sometimes homemade bricks have advantages over their industrial counterpart:

Factory-made material has a standard shape and size; by making it yourself, you can get rid of these limitations.
If the material and fuel are free, then a homemade brick will be the same free, regardless of labor.

Hand-molded brick looks like an antique, and fits well into the interior and exterior of buildings, as in the photo below. Although you can purchase factory material of this type for a decent price.

Also, if we are talking about unfired adobe brick, then it is not produced industrially at all. Now, in detail about the materials for all these types of bricks, and briefly, to make it more clear, about the technology of their manufacture.

Ceramic brick

The raw materials for this material are:

clayey rocks;
tripoli and diatomites;
mineral and organic additives;
water;
materials for textured bricks.

Now about each of the components in more detail.

Clays

This is the main raw material for the production of bricks; in fact, all other components of the molding mixture are just additives to the clay. Therefore, we will tell you about it in more detail.

Clays are sedimentary rocks formed primarily by the destruction of feldspars. In a completely dry state, it is dusty and when mixed with water it forms a thick plastic mass. Depending on the deposit, the composition may vary, but always includes one or more minerals of the kaolinite group - consisting of oxides of silicon (silica) and aluminum (alumina), as well as other chemical compounds.

Clay deposits

Clay deposits can be primary, that is, the rock is located where the decomposition of spars occurred, but secondary clays are more common:

Deluvial- transported by rain or snow waters. They are characterized by a heterogeneous composition and a large number of foreign impurities, and a layered structure. Deposits are usually associated with existing or former swamps, lakes and rivers and are located in low-lying areas.

Loess-like- the transfer was due to the wind. The deposits are characterized by rock homogeneity, porous structure and a large number of dust particles.

Glacial- the rock is transported with the movement of the glacier. Deposits are most often in the form of lenses with the inclusion of rocky particles, from small to huge boulders.

Types of clays according to the ratio of silica and alumina

Clay rocks are also usually distinguished by the ratio of clay and sand.

The types of rocks are shown in the table below:

Loams are mainly used for brick production. Clays are usually mixed with thinning additives, which can be sand or sandy loam. Clay sands are not raw materials for bricks.

The composition of the clay is given in the table below:

Let us present some properties of each of the oxides and talk about their effect on the characteristics of clay and finished (burnt) brick.

Alumina

The most important and refractory oxide in the composition. As its proportion in the clay composition increases, the plasticity of the mixture, strength and fire resistance of the finished products increase.

Silica

In large quantities, this mineral clogs the clay, and during firing it can destroy the brick or create cracks in its volume due to changes in the modification of quartz. But if its proportional ratio is not greater than in the table above, then silica reduces settlement and increases the strength of the material. Fine-grained sand improves drying of brick blanks.

Iron oxide and oxide

Gives the fired stone a red tint. When the content is more than 3 percent, it reduces the firing temperature. It enters the clay composition primarily as an impurity in colluvial deposits.

Titanium dioxide

It has virtually no effect on the properties of raw materials and products, except that it can give a greenish tint.

Calcium oxide

It is a harmful contaminant if included in the molding mixture in particulate form. As a result of firing the brick, particles are converted into lime, which, when interacting with water, increase in volume and destroy the material.

However, in a finely sprayed state it makes the raw material more sensitive to drying and reduces the formation of cracks.

Magnesium oxide

The effect on the properties of raw materials and materials is the same as that of calcium oxide, only less pronounced.

Alkali metal oxides

They reduce the firing temperature (called fluxes). Additionally, they reduce the coloring effect of iron and titanium oxides.

Also, clay almost always contains organic impurities; they give the molding composition a gray color and the finished products darker shades. They increase the plasticity of the mixture, but after firing they increase settlement and promote the formation of cracks.

Clays may also contain volatile substances that are removed during drying and firing. They increase the porosity of the material, which worsens its strength characteristics, but improves its thermal insulation properties.

This section of the article is given only for theory, and not for independently examining clay mined in a nearby quarry or simply on the bank of a river. However, when purchasing bricks or raw materials for its independent production, you can ask several questions that confuse the non-specialist seller.

Clay grain size

Clays are also divided according to the size of the particles that make up the rock and their relationship to each other. A set of sieves is quite inexpensive, so studying this characteristic is quite possible at home.

High dispersion- in the composition of particles passing through a sieve of 0.001 millimeters more than 60 percent and through a sieve of 0.01 millimeters more than 85 percent.
Dispersed- through a 0.001 millimeter sieve from 20 to 60 percent, and through a 0.01 millimeter sieve 40-85 percent.
Coarsely dispersed- fractions less than 0.001 millimeter less than 20 percent, and through a sieve 0.01 millimeter less than 40 percent.

Raw materials are also distinguished according to the size of large inclusions encountered:

small inclusions - size up to 2 millimeters;
medium - 2-5 millimeters;
large ones more than 5.

The best clay for brick is fine clay, it is the most plastic. Inclusions in the grain composition are unacceptable; they are screened out on a sieve or crushed when preparing the mixture for molding.

Plasticity of clay

It is determined by the difference in water saturation (absolutely dry rock is taken) between the thresholds when the raw material becomes a liquid mass and it can be rolled out.

Divided into the following categories:

difference in water saturation of more than 25% - highly plastic;
15-25% - medium plastic;
7-15% - moderately plastic;
3-7% - low plasticity;
less than 7% cannot form a plastic, rollable dough at all.

The greater the plasticity of the clay, the better quality brick it will make.

If you are going to make a brick yourself, then the easiest way to test the plasticity is to roll out a uniform ball of clay and crush it. The fewer cracks in the resulting “pancake,” the higher the plasticity.

Processes occurring in clay during firing

When clay is fired, moisture is removed from the raw material, and a chemical reaction occurs in which kaolinite is converted. Initially, unbound moisture evaporates from the raw material.

Then, when heated to a temperature of more than 500 degrees, the water included in the compounds is removed from the crystal lattice. If the temperature exceeds the limit of 1000-1200 degrees, then aluminosilicates mullite and sillimanite are formed, which are durable, hard and insoluble in water.

Tripods and diatomites

In addition to clay, some enterprises also use tripoli and diatomite to produce ceramic bricks.

These are mainly factories near large deposits of these rocks. They are sedimentary rocks, mainly of organic origin (remains of diatomite algae).

The chemical composition is given in the table below:

As you can see, these rocks are very close in chemical composition to clays, so they can be used in the production of ceramics. Brick made from this material has greater porosity than clay, and therefore has excellent thermal insulation properties, but less frost resistance and strength.

Supplements

In principle, brick can be made from only one clay, but in order to improve the properties and characteristics of the finished brick, facilitate molding and make drying and firing better, various additives are added to the composition of the raw material.

They are divided into the following types:

emaciated;
becoming emaciated and burning out completely or partially;
burning out completely;
enriching and plasticizing;
strengthening and fluxing additives.

Now in more detail about each type.

Leaning Supplements

It is added to excessively fatty raw materials to reduce the proportion of alumina and sediment of products. The following materials are used as leaning additives:

Quartz sand. Use only clean coarse sand (fractions 1.5-0.15 millimeters) without impurities. It is unacceptable to introduce carbonate sand into raw materials, even if it is contained in the form of impurities. Fine sand practically does not reduce settlement.
Chamotte is fired waste ceramic products. Grind to fractions of 1.5-0.15 millimeters. It is an effective clearing agent superior to sand. Better than other additives in reducing sediment. Up to 15% of the total volume of the mass is introduced, since a larger amount complicates the molding, however, if the brick is made by semi-dry pressing, then the proportion of fireclay can be increased to 25%.

Dehydrated clay is clay from which water has been removed by firing to 500-600 degrees. Also significantly reduces shrinkage. Enter in amounts up to half the volume of the mass. Simultaneously with the dihydrated clay, coal must be added and the firing temperature increased by 35-50 °C.

Leaning and partially or completely burning out additives

Wood sawdust. They facilitate the molding of bricks, but reduce the strength of the product and increase its water absorption. The introduction of sawdust also reduces the density of the brick and, consequently, its thermal insulation properties. Preference should be given to slitting sawdust, since the fibers reinforce the brick. They also increase frost resistance. Up to 10% of the total volume of the mass is introduced, a larger amount worsens the appearance of the products. It is effective to introduce another clearing agent together with sawdust - coal or fireclay.

Lignin is a waste product during the production of alcohol by hydrolysis from wood. Reduces shrinkage and cracking during drying. In addition, it is also a plasticizer. Add up to 20% of the total mass. If it is necessary to obtain a porous brick by reducing strength, then the proportion can be increased to 40%.

Peat - milled and waste from the production of briquettes. It is used as a last resort in the absence of other thickening agents, since due to its high moisture capacity it slows down drying and deteriorates its quality.

Furnace slag is an effective slag that improves the quality of firing. It is advisable to use up to 10% sawdust simultaneously.

Ashes from thermal power plants, waste from the combustion of coal dust, in addition to their depleting effect, improve the quality of firing, since they include a small amount of unburned fuel. Up to 45% of the mass volume is introduced. It is effective to mix with other additives, such as sawdust, before administration.
Coal enrichment waste is predominantly shale rocks containing up to a third of combustible substances. They are used in the same way as thermal power plant ash.

Burn-out additives

Solid fuel is used as burnable additives - various types of crushed coal, coke, etc. They are added up to 3% of the volume of the initial mass, and fuel resources for the production of bricks from these additives can amount to up to 60-80% of the total fuel consumption required for making bricks.

The main task of burnout additives is to speed up firing and improve the sintering of raw materials, and hence the strength of the finished brick.

Advice. Do not neglect these additives when making your own bricks. By introducing them into the mixture, you can achieve high-quality firing even in a small oven.

Enrichment and plasticizing additives

Used to increase the proportion of alumina in the mixture, as well as to improve brick formation and reduce the formation of cracks and shrinkage. They are used as enriching and plasticizing additives.

Highly plastic clay. It is added to the composition if the alumina content in the feedstock is less than 7-8%. It enriches the mixture with alumina and increases their plasticity. It is administered as a suspension with a moisture content of 40%. The amount of highly plastic clays in the mixture can reach 20%.

Waste from coal mining. Rocks discarded during coal mining or beneficiation may contain alumina and be used as an enriching additive for the mixture intended for making bricks. Plastic waste is introduced in the form of an aqueous suspension, solid waste in the form of finely ground dust to facilitate mixing.

Bentonite clays. The mixture is enriched and plasticized due to the large amount of hydroalumina silicate (up to 70%) in the composition of bentonite. The disadvantage is that bentonite clays expand in volume as humidity increases. Increases sensitivity to drying. Added in amounts up to 3% of the volume of the raw mixture.

Surfactants form a film on the surface of the mixture particles, which acts as a lubricant and increases the plasticity of the composition while reducing the amount of water required for mixing by 2-4%. The introduction of a surfactant also improves moisture transfer, both during drying and during firing, and prevents the formation of microcracks, which means it increases the strength of the brick.

Extracts from straw and peat. Prepare by boiling peat or straw for 15-20 minutes (take 1-2 kilograms per 10 liters of water). You can also get it using a 1% solution of caustic soda without boiling. Add to water intended for preparing molding sand in an amount of 50%. In this case, plasticity more than doubles.

Advice. If you are planning to make bricks yourself, then this is one of the most affordable plasticizers (not counting purchased ones).

Sulfite-alcohol stillage. In the pulp industry it is a waste. In addition to surface-active properties, it also has adhesive properties, due to the presence of resins and sugars in the composition. Increases the strength of brick by 3-4 MPa. It is introduced into the mixture in the form of a one percent aqueous solution.

Yeast waste. They represent waste water used for washing yeast. Administered in an amount of 4%. It works exactly like other plasticizers.

Strengthening and fluxing additives

Pyrite cinders, a waste product from the production of sulfuric acid from iron pyrites, are used as strengthening and fluxing additives. Helps accelerate sintering and increase the strength of bricks. The higher the firing temperature, the more pronounced their effect. They also somewhat reduce the sensitivity of the mixture to drying.

Materials for textured bricks

Used primarily for facing bricks. They are added to the mixture used to form the front part of the brick, or applied separately to this surface.

Light clays

As a rule, they are low-melting (sintered at low temperatures). Change the color of the brick surface to a lighter color (if it contains titanium oxides, then with a greenish tint). They also increase the fire resistance of the surface layer of the brick.

Fusible glass

It is used primarily for making glazed bricks.

The surface can be either glossy or matte by mixing glass and clay. Waste (cullet glass) is most often used as a texture additive, but in some cases blocks of glass of the required color are purchased.

Quartz sand

Used as a surface layer protectant. Should not contain iron compounds.

Scrap porcelain and refractory products

Production waste is used, which is thoroughly crushed in mills before being added to the mixture.

Preparation of materials for brick molding

We told you what materials are used to make ceramic bricks. However, the raw material must be prepared before molding. Additives are crushed or mixed (dissolved) with water.

Most operations are carried out with clay. The fact is that when it is extracted in a quarry (especially if the deposit is secondary), it is always heterogeneous; even samples taken at a short distance from each other differ in chemical composition, humidity and foreign impurities. Before preparing the molding mixture, the clay is averaged.

For this:

mix the clay at the mining site with an open-bottomed ladle;
if possible, let the clay sit in dumps at the site of mining or brick production for several years, it freezes (it goes through several freezing-thawing cycles) and becomes looser and more homogeneous;

Before preparing the mixture, it is passed through rollers, which grind the particles, sift to remove rocky inclusions and mix thoroughly.

Optimal mixture composition

In production, specialized laboratories are involved in the selection of mixtures for bricks. After analyzing the raw materials, they select the ratio of clay and additives in order to obtain high-quality bricks.

Moreover, the moisture content of the mixture before molding can be different. If the brick is made using the most common plastic molding method, then the initial mixture will contain more than 20 percent water. When produced by semi-dry pressing, about 7 percent.

The second production method involves the use of presses for molding raw material, therefore it is least suitable for making bricks with your own hands. But when using it, drying of raw bricks is avoided; firing can be carried out immediately after molding, which reduces fuel costs and production time. The downside is that semi-dry pressed brick is somewhat more porous and has less frost resistance.

If you are going to make bricks yourself, then, naturally, you cannot do this, because this requires special equipment. Therefore, we can advise you to turn to old methods that have been known for hundreds of years.

The instructions are as follows:

Mix about half a kilogram of clay, gradually adding water until the mixture stops sticking to your hands. Make several similar batches with different ratios of sand and clay, recording the proportions.

Advice. It is better to scratch the batch number on the sample with a pin or toothpick. Naturally, we write down the proportions on paper.

From the mixture we make samples in the form of a ball with a diameter of 5 centimeters and a disk with a diameter of 10 centimeters.
We dry our samples at room temperature.
We select the batch (the proportions of which we wrote down) from which the highest quality samples were obtained. They must be free of cracks, and the ball must withstand a fall from a height of about a meter without damage.

Sand-lime brick

This type of brick, as we have already said, appeared much later than ceramic brick - its mass production began in the late 19th and early 20th centuries. As we already noted at the beginning of our article, the main advantage of this material is its low cost.

Making sand-lime bricks at home is almost impossible (we’ll talk a little about the technology below), since it requires presses and autoclaves that are impractical to construct or purchase for small-scale production. Therefore, this part of our article has rather an informational value.

In order to make such a brick, you need only three materials - sand, water and lime. If a colored material is needed, then pigment is additionally added to the mixture.

Sand-lime brick production technology

Although our article is devoted to raw materials for production, and not to the production itself, in this section we will briefly describe how silicate bricks are produced so that the requirements for raw materials are more clear.

There are two ways to prepare the raw material:

Silage - quicklime or its mixture with hydrated lime, as well as sand, are mixed and, at low humidity, loaded into tower-type containers (silos) for slaking. The process takes 8-12 hours.
Drum - a mixture of lime and sand is quenched in sealed rotating drum containers with steam, under a pressure of 0.15-0.2 MPa (1.5-2 atmospheres). The process takes less than an hour, and additional mixing of the components also occurs.

Then the mixture is pressed under pressure into brick blanks, which are sent to autoclaves, where they are treated with live steam at a temperature of about 180 °C under a pressure of 0.8 MPa. Moreover, the parameters are raised to the required ones within an hour and a half, then kept for 5-6 hours and also slowly reduced.

During this treatment, water, Ca(OH)2 and SiO2 (slaked lime and sand) react to form strong, water-insoluble compounds.

Sand

This is the main component of the mixture; the consumption of raw materials for brick production is 90-95 percent of the volume (excluding water). Only pure quartz sand is used (to reduce transport costs, silicate brick production is often built near its deposits). The requirements for sand for the production of sand-lime bricks are somewhat different from the requirements for sand for preparing mortars; we list them.

The fractional composition of the sand should ensure the most dense packing of its particles (minimum volume of empty spaces between the grains). To do this, the sand is sifted and crushed (grinded) to obtain small particles.
Clay inclusions should be no more than 10%.
The presence of more than 0.5% mica inclusions is not allowed. During heat treatment, it will swell, which will lead to the formation of cracks and cavities inside the material.
The presence of organic and sulfur impurities is not allowed.
The grains should, if possible, not be round in shape, but have a rough surface. Therefore, instead of river sand, it is advisable to use mountain sand.

Lime

This is the second component of the raw material mixture for sand-lime brick; it is contained in the dry composition for molding 5-10%. Quicklime or hydrated lime, as well as a mixture of them, are used. The following special requirements apply to lime.

It should be finely ground.
The content of magnesium oxide (MgO) is no more than 5%.
Lime slaking should be as fast as possible.
The presence of burnt particles is not allowed.

Raw brick (adobe)

Adobe brick is essentially a semi-finished ceramic product - raw, which can then be fired. According to one version, having discovered that adobe, unintentionally burned by the flame of a hearth or fire, acquires greater strength and water resistance, people invented ceramics.

Therefore, its composition is almost the same as that of ceramic bricks - clay, sand, water and additives. In addition to them, materials are introduced into the mixture that reinforce the products. Let's take a closer look at each component.

Clay

Exactly the same as for ceramic bricks, which are also pre-prepared (averaged, mixed). If necessary, sand and additives are added to it, adjusting the proportion of alumina in order to achieve plasticity and minimal shrinkage.

Advice. Almost always, a mixture ideally selected for plasticity and shrinkage does not lag well behind the shape (for adobe it is often made of wood). You should not add water, it is better to lubricate or simply wet the mold.

Sand

It does not have such stringent requirements for impurities, since there is no firing. For example, organic substances will not reduce the strength of adobe if they are present in the form of remains of unrotted roots and other parts of plants.

Supplements

The list of additives that are added to adobe is smaller than for ceramic bricks, which is also due to the absence of a firing stage. This is understandable - fluxing and burning additives are useless.

Also, the surface of adobe brick is not textured; during construction, masonry made from this material is usually protected from moisture by other materials, and not exposed. Only thinning or enriching additives and plasticizers are introduced into adobe.

Reinforcement materials

To reinforce the entire volume of raw brick, materials with greater tensile strength than clay are added to the mixture. As a rule, they are of plant origin. The word “saman” itself is translated from the Turkic language as straw. Let's list what can be used to reinforce raw brick.

Finely chopped straw. It doesn’t matter what kind of grain it may be: wheat, rye, oats, etc., the main thing is that it is dry and not damaged by rot.
In the absence of straw, use hay and reed stalks.
Sawdust is best for cutting wood along the grain.
Bonfire is a waste product from the ruffling of textile plants (flax, kenaf, hemp).
Chaff is waste in the form of small plant parts during threshing of cereals.
You can also add polymer materials, trimmings of polyethylene twine, etc. to the composition of the mass.

In desert areas, farm animal dung was added to adobe, naturally making bricks for the house; no one will use this material.

We hope that in our article we have sufficiently covered the topic - what brick is made of. In our opinion, after reading it, you can even pass an exam at an educational institution. The material presented will also be a good help if you are planning to make one or another type of brick at home. Let your home be durable and comfortable from it.

It's nice to have a house outside the city! But what if there is a plot of land, but there is no money for building materials? So, you need to build from what you have!

Materials for making bricks and blocks

Today everyone is accustomed to buying ready-made building materials. And our ancestors did everything with their own hands. And their houses were strong, warm, cozy.

Today's craftsmen also began to make bricks with their own hands for the construction of country houses. A variety of materials are used for this.

You can make the following building materials at home:

concrete cinder blocks;
adobe bricks;
terrablocks.

With diligence, labor and patience, all the work can be done without any purchased mechanisms. And the financial investment on the material can be kept to a minimum.

Brick and block molds

Of course you can buy them. But since you decide to do everything yourself, then you should build the molds for filling yourself. Moreover, ready-made bricks will be useful not only for building a house, but also for building a poultry house, garage and other utility rooms.

If possible, you can make metal molds. But the easiest option is to put them together from plywood or wooden planks.

They make either single molds, double molds, or multi-piece molds. First, the walls of the box are knocked together. It is best to make the bottom of the mold retractable. But the covers are not attached in any way, but are simply placed on top. It is recommended to fill them with cone-shaped cones to create voids in bricks and blocks.

Although some craftsmen make do without lids at all when making bricks. Their bricks and blocks are cast, solid, without voids. In this case, more material is consumed, and the thermal conductivity of the walls is higher. That is, housing is less warm, since it is easier to share temperature with the environment.

If the mold is made for casting two or more blocks or bricks, then partitions are inserted inside. They can be made either stationary or removable. The latter option is considered more successful, since the bricks can be removed without any problems after removing the partitions.

Molds for making blocks and bricks differ only in their sizes. Moreover, everyone chooses for himself how large his building materials will be.

Concrete cinder blocks

This option is the most expensive of the three mentioned above. But, nevertheless, by making the blocks yourself, rather than purchasing them, the master significantly saves money.

For a concrete cinder block you need to take:

1 part cement;
6 parts sand;
10 parts filler.

The filler is expanded clay or crushed stone. But a thrifty owner can replace purchased ingredients with ordinary garbage, which is easy to collect in his yard, from his neighbors, or (forgive me, people with an aristocratic upbringing!) in a landfill.

It is important to use as a filler something that does not rot and does not shrink.

These are:

broken glass;
stones;
pieces of brick;
plastic;
small metal parts.

When combining ingredients, it is necessary to measure the parts based not on the weight of the materials, but on their volume.

The volume of filler is calculated using a method based on Archimedes' law.

To do this, you will need a container of known volume and water. First, they put the material into it. Then fill everything with water, filling the container completely. After this, all that remains is to simply calculate how much water fits, subtract this number from the known volume of the container. What will remain is exactly the figure that will be equal to the volume of the material being measured.

Adobe bricks

To produce building materials of this kind, the following ingredients are required in equal volumes:

clay;
sand;
wet manure or;
filler.

The following are used as fillers:

crushed insulation fibers;
reed fines;
shavings;
sawdust;
chopped straw.

You can add lime fluff or cement to the mass to increase strength.

If you have difficulty finding peat or manure, experts advise making your own stabilizer for bricks. To do this, vegetable tops, leaves, and weeds are dumped into a special pit and filled with clay solution. After three months, the rotted mass can be used as an ingredient for making adobe mortar.

Terrablocks

It is even easier to use ordinary earth as a material for bricks and blocks.

For earthen bricks, you should not take the top layer of soil, in which plant roots are found in large quantities, but those located deeper. Silted soils are not suitable for work.

Ingredients for Terrablocks:

1 part clay;
9 parts of earth;
5% fluff;
2% cement;
filler (slag, garbage, crushed stone, expanded clay, crushed insulation).

You can mix the ingredients for the composition with your feet by placing it in a hole, a large container like a bathtub. There is an option to perform this work using special devices - soil mixers, which resemble miniature concrete mixers.

Drying bricks

Concrete bricks and cinder blocks dry in one to two days in good warm weather. But adobe and earthen building materials have to be kept under a canopy for a week or even about half a month. A canopy is necessary to protect bricks and blocks from precipitation and sunlight.

Moreover, adobe and terra bricks are first dried in a horizontal position for 2-3 days, and then turned over on their side. After a few days, they are transferred to the opposite side, then with the bottom part up.

If brick production occurs in winter, for drying it is necessary to equip a room with walls, a ceiling and heating.

It is very important to remember when building a house from adobe or earthen bricks: finishing cannot be carried out earlier than a year after the construction of the walls!

This rule follows from the fact that buildings made from this building material have a tendency to shrink strongly.

Video about how to make earthen bricks using a simple homemade machine

Brick is one of the oldest and most popular building materials. This is, in fact, a stone of regular shape, made artificially, the masonry of which is significantly lighter.

What a brick is made of depends on its type and purpose, as well as on the production method.

Source materials and their characteristics

Before talking about the composition and manufacturing technology of bricks, we must make a reservation: there are two main types of this building material. Ceramic, or red, and silicate or white, consisting of sand and lime. Let's start with the most common red brick.

Raw materials for the production of ceramic bricks

The production of red ceramic bricks can be divided into three main stages:

Selection and extraction of clay, preparation of charge;
The process of forming and drying bricks;
Final firing of the product.

We will talk specifically about the first item on this list. Since the formation of the quality of the final product begins in the quarry.

As you know, modern building blocks are made in brick factories, and for such large enterprises the important conditions are:

stability of indicators of homogeneity of the chemical composition of clay;
sufficiently large volumes of raw material deposits with the same properties;
clay purity;
presence of foreign inclusions;
plasticity of the material;
fat content;
presence of limestone inclusions;
presence of plant residues.

Important!
A homogeneous chemical composition with significant volumes of deposits allows for a minimum number of expensive laboratory tests aimed at determining the optimal composition of clay mixtures used for the production of products.
In addition, this allows you to set the most productive conditions and modes of drying and firing, which together affects the stability of the entire enterprise, as well as the quality of the products.

The clay extracted for the production of ceramic bricks must, if possible, meet the following requirements:

have a minimum content of large and medium-sized rocky inclusions;
contain a minimum amount of plant residues;
include as little limestone as possible, since its presence leads to the formation of calcium oxide during firing, which, under the influence of atmospheric moisture, undergoes a quenching process, increasing in volume, and forms the so-called. “dusts” in the body of the product, and large volumes of this substance completely destroy the building brick;
it is desirable to have thick layers of homogeneous clay;
clay should have average plasticity;
The raw material must have sinterability acceptable for the chosen firing method.

Next, it should be said about this indicator of the quality of raw materials, and in our case, what red brick is made from is clay, like plasticity. If we introduce the definition of this term, we can say that plasticity is the ability of a material to take any shape without rupture under the mechanical influence of external forces, and the adopted shape must be maintained after the end of such influence. Sometimes plasticity is called fat content.

According to the degree of fat content, clays are divided into:

non-plastic,
low-plasticity,
moderately plastic,
medium plastic,
highly plastic.

This property depends mainly on the amount of aluminum oxide in clay-forming mineral compositions: the more it is, the higher the plasticity of the clay. Also, with an increase in aluminum oxide, the fire resistance and strength of the formed and fired products increases.

Also, the plasticity of the raw material affects the percentage of liquid input when obtaining the molding mass. Low-plasticity varieties of clay require the input of 15–20% water, while high-plasticity ones can take up to 30–40% into their composition, and such an amount of liquid can lead to cracking of products, loss of shape, and also significantly lengthens the drying process.

To reduce plasticity, various thinning agents such as sand, shale, sawdust or coal water are usually added to fatty varieties.

Another important quality indicator is the binding ability of clay. This is an indicator characterizing the ability of a material to maintain plasticity when adding the above-mentioned thickening agents. Based on the amount of sand that clays can bind, they are divided into low-plasticity (less than 20%), plastic (from 20 to 60%) and high-plasticity (from 60 to 80%).

The next and one of the most important characteristics is the sensitivity of the clay used in production to drying. The fact is that during processing, air and fire shrinkage occurs, which manifests itself in the form of changes in the linear and volumetric dimensions of bricks formed from clay raw materials during firing and drying.

To determine the degree of sensitivity of the material to drying, special marks are applied diagonally to the sample, and the distance between them is measured before and after the drying/firing process. Samples with high ductility shrink more than 10%, and this negatively affects crack resistance and shape retention during heat treatment.

Important! The raw materials from which ceramic bricks are made should ideally have a medium degree of plasticity and have shrinkage rates within 6 - 8%.

Finally, an important indicator of the quality of a clay material is its sinterability. This is the property through which raw materials, when heated, acquire the qualities of a stone-like body, i.e. compacted and strengthened.

Based on this property, clays are usually divided into the following categories:

Low-temperature, sintered when heated to 1100 °C;
Medium temperature, sintered at temperatures from 1100 to 1300 °C;
High-temperature, sintered at temperatures exceeding 1300 °C.

Important!
The interval between the onset of deformation and sintering is no more than 100 °C, therefore the selection of an acceptable sintering interval is an important procedure for the production technology and processing of the product.

As you can see, the selection of raw materials for the production of ceramic bricks is a complex and multi-level task that requires a number of laboratory studies and experiments. Of course, with your own hands (hand molding), the instructions are not so strictly defined, but with modern production in a factory environment, not only the quality of the final product, but also the stability of the enterprise’s operation depends on this.

Raw materials for sand-lime brick

When producing white or sand-lime bricks, including double sand-lime bricks M 150, sand and lime are used. Moreover, the mass fraction of sand is 85 – 90%. Therefore, the quality of the final product mainly depends on the quality of the sand used.

Sand is mined in river quarries, from fuel slag, blast furnace and water jacket slag, from waste from crushing rocks, i.e. from both natural and artificial sources.

The sand coming from the face is screened from stones, branches, clay, metal inclusions and other foreign impurities using drum screens.

The formability of the silicate mixture is influenced by the shape and nature of the sand grains; also, these characteristics are of no small importance for the strength of the raw material and the rate of reaction with lime during autoclave processing.

The second component of the silicate mixture is lime. This includes carbonate rocks containing at least 95% calcium carbonate. These can be chalk, marble, limestone tuff, shell rock and dense limestone. At factories producing sand-lime bricks, only quicklime is used.

A silicate mass (what bricks are made from) is prepared from sand and lime using a silo or drum method, while the silo method is preferable from an economic point of view, since it does not consume water vapor to slak the lime.

The silicate mass is further pressed into, which is delivered to the autoclave for treatment with saturated steam. When undergoing a full cycle of such treatment (from 10 to 13 hours), sand-lime brick acquires its strength properties and can be shipped to consumers.

Important!
In general, the production process of sand-lime brick is simpler and less picky about raw materials, so the price of white brick is lower than red.
However, the properties of this building material are in many ways inferior to ceramic products.

Conclusion

High-quality products are the key to the durability of the structure

The quality of the materials that make up the brick greatly influence the quality of the final product. Therefore, brick factories are forced to carry out reconnaissance and laboratory testing of all raw materials used. In the video presented in this article you will find additional information on this topic.