Adobe

Saman is one of the oldest building materials. It was used by the ancient Egyptians as early as 5-4 millennia BC. e. The adobe walls defended the second Troy (2600–2300 BC). The material was mainly used in places that did not have forests, and, as a result, the possibility of erecting wooden structures ^[1] .

Clay soil is diluted with water, knead in pits, crates or on flat areas and thoroughly mixed with additives.

• increase tensile strength of cellulose fibers:
  • chopped straw
  • bonfire
  • chaff
  • wood shavings
  • manure
• reduce shrinkage when dried:
  • sand
  • gravel
  • crushed stone
  • expanded clay
• accelerate hardening and increase water resistance:
  • cement
  • lime
• improve stackability ( plasticizers ):
  • liquid glass
  • casein
  • bone glue
  • milk serum
  • slurry
  • syrup
  • starch , etc.

Raw tensile strength of clay concrete depends on the fat content of clay and the preparation time of the mixture. The optimum mixing time is determined empirically on small samples.

Molds for making adobe are made single, double, triple, quadruple and even 5 bricks. Forms for large blocks are made in the form of a box without a bottom, firmly knit together from boards with a thickness of 25-30 mm. Molds for adobe bricks of small sizes are made in the form of a box with a bottom. The dimensions of raw brick do not have clear standards and, depending on local conditions, can be large, medium and small in size (25 × 12 × 7 cm).

It is better to form adobe brick in spring, so that during the summer the wall can dry well in the sun. Work is carried out on a flat site. The mold is moistened with water, sprinkled with chaff so that the clay does not stick to the walls. They take a lump of clay, approximately equal to the volume of the mold, and fill it with a mold, tamp with a manual tamper and smooth it, or throw the lump of clay into the box with force, thereby achieving its compaction. Excess clay is removed and mixed with the total mass. After tamping, the form is removed and transferred to another place for the next filling.

Molded bricks stand on the molding site for three days. If the site is properly arranged, there is a good rainwater runoff, then a little rain is not dangerous, otherwise the adobe is placed under a canopy. After aging and drying, the bricks are laid flat on the edge, with a gap between the side faces for free passage of air and dried for another 3-7 days, then put into cells, where the adobe finally dries and hardens. A good brick is durable, does not break when falling from a height of two meters.

During the construction of buildings, adobe is laid manually.

Clay concrete density without lightweight aggregates - up to 1900 kg / m³. With a high straw content, the density is from 500 kg / m³, such a material is a good heat insulator. Thermal conductivity from 0.1 to 0.4 W / m ° C

The compressive strength of dried adobe and raw brick ranges from 10 to 50 kg / cm² and is comparable to gas and foam concrete with a density of 600 kg / m³ (tensile strength 25–40 kg / cm²).

Benefits:

1. Low cost - no firing fuel is required, the source material literally "lies under your feet."
2. Large thermal inertia and sound insulation of walls due to their mass.
3. Fire resistance options with a small amount of pulp.
4. Stabilization of humidity in the room due to the enormous hygroscopicity of clay.
5. Environmental friendliness.

Disadvantages:

1. Low moisture and frost resistance. Often plastering of the outer surface or other protection against dampness is required.
2. Rodents, insects, mosses, fungi can live in adobe.
3. If construction takes place in frosty weather, chemical additives are needed for mixing water to lower its freezing temperature.
4. Long drying of walls and a set of strength in a temperate climate.
5. According to the Russian Construction Norms and Regulations II-22-81 “Stone and Armored Stone Structures” (2003), raw brick and soil stones are allowed to be used only for the walls of buildings with an estimated service life of no more than 25 years.

In commercial construction, it is necessary to achieve guaranteed material strength at a given time regardless of the weather. To do this, it is more convenient to use the same aggregates on a cement binder instead of clay, which is no longer adobe.

Particular attention should be paid to the fact that the construction of any adobe structure should be carefully isolated from the possible penetration of moisture. As a rule, moisture can get into the walls from oblique rains, the action of capillarity forces, that is, from the soil, as well as due to poor insulation: roof malfunction, internal condensation of vapor penetrating the walls, water splashing from the roof to the ground and etc.

Among the means of reliable protection of adobe walls from moisture can be attributed the construction of foundations and socles made of waterproof materials: rubble stone , brick, concrete. In this case, blind areas should be arranged so that rain water, spray and snow do not fall on the walls. It is also important to carefully arrange the waterproofing layer under the walls, unloading belts, doorways, window sills, thresholds, Mauerlat, the implementation of eaves with overhangs of at least 50 cm.

For the installation of foundations for adobe walls, it is recommended to use rubble brick and stone, monolithic and precast reinforced concrete. The height of the base must be at least 50 cm from the foundation. In this case, the base should be carefully isolated with roofing material , roofing felt or film. The basement must be at least the thickness of the outer and inner walls. For external walls, the thickness is determined depending on the calculated temperature of a given climatic region, but not less than 50 cm, and internal - not less than 30 cm.

In the lower layers, to prevent penetration of rodents into the wall, broken glass can be mixed into adobe.

Walls of adobe erect before the onset of autumn frosts. In the summer, walls of adobe blocks (bricks) are laid out on a clay-sandy mortar with a composition of 1: 1 or 4: 3, depending on the clay content. To improve the quality of the clay mortar, fine straw cutting, chaff, etc. are added to it. In the spring and autumn, the masonry is carried out on a lime-cement mortar.

To reduce, and to avoid settlement of buildings, the thickness of horizontal joints should be minimal (1 - 1.2 cm).

In the process of erecting adobe walls around the perimeter below the window openings and at the level of lintels, reinforcement is laid from boards, brushwood or reeds. Knots and interfaces should be reinforced with these materials every 50 cm in height. The distance between the axes of the reed stalks is 5 cm. In angular mates, the stems of both directions must be laid with thick ends in the corner of the wall, after having flattened them with a light blow of a wooden hammer for better adhesion to the solution.

• Kotelets
• Arbolite
• Duval
• Icelandic turf houses
• Adobe buildings

• Efremov G. Adobe brick - affordable building material // Do it yourself: almanac. - M .: Ogonyok, 2001. - March-April ( No. 2 ). - S. 3-21 .
• Minke G. Clay concrete and its use. - Kaliningrad: Amber Tale, 2004 .-- 232 p.
• Saman // Brockhaus and Efron Encyclopedic Dictionary : in 86 volumes (82 volumes and 4 additional). - SPb. , 1890-1907.
• Ianto Evans, Mike J. Smith, Linda Smiley. House of adobe. Philosophy and Practice. - Kiev: Rіdna Zemlya, 2004 .-- 348 p.
• Buzukh Yu.V. Silence for body and soul // Melitopol Local History Journal, 2018, No. 11, p. 43-53.