Raw brick: composition, properties, manufacturing, application

The raw brick (another name for this building material is Saman) is an excellent building material. It has long been known to mankind, it is simple and convenient in manufacturing and application. The adobe is more common in southern places, but it is sometimes found in the middle band.

Excursion to the history

The first buildings, where the raw brick was used, appeared almost six thousand years ago. In this there is nothing surprising, since a person needs to live somewhere, and funds for building housing are often not enough. And it always was: now, a hundred years ago, a thousand ... If it is a matter of living near mountains or in the woods, then there are cheap construction materials in sufficient quantity. But what about those who live in steppes or deserts? There stone and wood were very expensive and not all were available. Of course, houses were built from expensive building materials and there, but not everyone could afford this luxury. And then, in the fourth millennium BC, a method was found for erecting clay constructions with an admixture of straw.

Properties of adobe, pluses and minuses

A raw brick with cut straw is a very convenient building material. Its advantages include an extremely low cost price. After all, the cost of its production is almost zero, since the raw materials lie literally under their feet. Another advantage of using this building material is its sound and heat insulation characteristics. Also, the adobe is hygroscopic, due to which it has a favorable effect on the microclimate in the room, absorbing excess moisture and preventing the appearance of dampness and mold inside. Also, raw brick, as well as any building material, which is based on clay, fireproof and provides significant fire safety of the structure.

But this building material has several drawbacks. The walls of raw brick are afraid of moisture, so a good layer of quality plaster is needed to protect them. With a mild climate, the brick dries for a long time and slowly gains strength. Also, an adobe is not suitable for building in winter. Even in the walls of raw brick often like to settle rodents and other pests. This can be prevented beforehand by applying special additives or by properly treating the surface. Among other things, the building of this brick is erected a little longer, because the walls need more time to reach the required fortress.

Raw brick and its types

Saman is of two types: light and heavy. For the construction of a light adobe brick as such is not needed at all. A mixture of clay and filler is prepared, the filler being taken proportionally more than the clay, and superimposed on the wooden frame of the structure with the crate. Sometimes an adobe is simply laid between the inner and outer wall panels. The advantages of this method are simplicity and speed. Disadvantages - it takes a lot of wood. Heavy Saman - this is the same raw brick with straw. Houses from it are obtained much stronger, more reliable, are built from ready-made blocks. Wall decoration is possible immediately after the completion of construction.

Material selection

Roasting of raw bricks is not done, therefore, in order to make it qualitative, and the structure - strong and reliable, we must initially pay attention to the choice of material, that is, clay. A brick made of low-plastic clay will turn out to be brittle, and from a very greasy clay it will crack from temperature and humidity changes. There are many ways to determine its quality. Let's consider some of them.

Method one - stir the clay to the required viscosity, we make from it three small cubes with sides of 20 cm. The first cube should be only of clay. In the second you need to add about 10% of the sand. And in the last cube you need to add fatty clay, also in the proportion of 10-15%. On all the cubes on one side with a stick or nail crosswise diagonally we make shallow lines. Their width is about 5 mm, and the length is 10 cm. The cubes are dried for a week and a half, and then the lines are measured. That clay, where the lines are shorter by 6-10 mm (compressibility 6-10%), is optimal for the manufacture of adobe bricks.

Method two - the clay is well kneaded, form a ball about five centimeters in diameter and smoothly squeeze it with two even boards. The clay of low plasticity begins to crack when the ball is compressed to the fifth or fourth part of its diameter. Average plasticity - cracks appear when the diameter of the ball is compressed by one-third. High plasticity - cracks when compressed to half the diameter. Optimal plasticity is average. We bring to the desired plasticity with sand or greasy clay.

The third method consists of a well-kneaded clay with a length of about 20 cm and a thickness of 1-1.5 cm. The roller is wound on a tube 20 cm in diameter. The low-density clay strongly cracks and tears, the highly plastic remains completely without cracks, and the most suitable clay composition is formed A grid of small cracks.

Preparation of clay

The best option would be to prepare the clay ahead of time. Fold it in stepped ridges with a width down to two and a half meters and a height of up to a meter. Pour each stepped layer with water and hold the material one winter. But you can use clay without preparation. It is necessary to mix up so much clay in order to have enough work for one day. For calculation: in order to produce 1000 pieces of standard raw bricks, almost 3 cubic meters of clay are needed. It is sprinkled with layers of 15-20 cm, crushed and mixed with greasy clay or sand and with the filler that is selected, that is, with chopped straw, chaff, scotch, etc. It needs to be done gradually and only in a dry state. At the edges of the work platform, clay skirts are made to hold water. Then they begin to fill the mixture with water. Usually there is water about 20-25% of the amount of clay. Stir clay to a homogeneous mixture of shovels, legs, can be concrete mixers.

Manufacturing of brick blocks

As a rule, the sizes of adobe blocks are of three types and depend on the climate of the area where the house is built. The drier and hot the climate, the larger the size of the blocks, as they can dry out well and gain the necessary strength. Small blocks have dimensions of 30x14x10 cm. Medium sizes are 30x17x13 cm. Large ones are 40х19х13 cm. Do not forget that in the process of drying bricks lose up to 10-15% of volume. Therefore, the shape is made 5-6 cm larger than the future brick. Forms can be made on one, two or four bricks. You can do without the bottom, but you can with the bottom in the form of boxes with handles. For better separation of the finished product from the form, it is possible to enclose its walls from the inside with dense polyethylene. Brick blocks are produced at the same place where they will be dried in the future. If necessary, the clay mixture is brought on the trolley, it is superimposed with a shovel into the molds with the top, it is rammed by the board, the surpluses are carefully cut off, and the blocks are laid out to dry.

Drying of finished products

A ready-made brick is pierced in 2-3 places with a thin (1.5-2 mm) wire and held for three days on a molding pad. Periodically it is turned over for uniform drying. After this period, the blocks are placed on the edge and dried for 3-5 more days. And then the bricks are stacked with a small gap between them. Above the blocks are covered with mats, shields, tarpaulin, polyethylene, etc. The main thing - do not allow moisture to enter during drying. The drying process takes place depending on the weather conditions from 2 weeks to a month. The degree of readiness can be determined by looking at the kink. The entire surface of the fracture should be monophonic, without spots in the middle. Also thrown from a height of two meters, the brick should remain intact and put in 48 hours in the water should not lose its shape.

Building a house from adobe

As has been repeatedly mentioned, during the construction of raw bricks, special attention should be paid to the insulation of walls from moisture.

The foundation for blocks from adobe is preferable to the tape type, centimeters 20-25 wider than the masonry itself. This is done to protect the walls from rain spray. The height of the foundation is 50 cm and above. The material is rubble stone or concrete. A layer of waterproofing is required on top of the basement.

The walls are usually built: the outer walls are 50 cm thick and the inner ones 30-40 cm. The solution is made of water, one part of clay and one part of sand. Also, the clutch can be reinforced with reeds, brushwood or straw. You can not do masonry in the rain. We must immediately cover the walls and wait for the dry weather. You can not build walls in winter. Immediately after the erection of the walls, it is necessary to finish them with plaster. It is better to take gypsum plaster, since the cement plaster has insufficiently good coupling with the raw brick.

The roof is made light to reduce pressure on the walls, and with a large overhang to 70-80 cm to push the drain away from the walls. The floor can be insulated with expanded clay, and from above it can be made boarded on logs.

Conclusion

That's all the main points that are related to the production of raw bricks and what is worth paying attention to when building a house from it. It is profoundly mistaken to believe that such a building is short-lived. A house made of adobe, built with the observance of all technologies, will last for more than one hundred years. In such houses it is warm in winter and cool in summer. It is not by chance that interest in houses made of adobe blocks comes back around the world.