The construction of external walls is made of brick. “Study of brick wall structures. Basic properties of brick surfaces

• Basic properties of brick surfaces
• Design brick wall
• Basic Rules brickwork
• Types of brickwork
• Types of distribution of masonry according to wall thickness
• Making a brick wall
• Required Tools

Since ancient times, a brick wall has been the basis of a wide variety of structures. Ancient structures have withstood all adversity and now continue to delight the eye. Houses with such walls are built to last.

Nowadays, many building materials have been developed and used that allow construction to be done quickly and efficiently. However, the brick wall still remains out of competition.

Basic properties of brick surfaces

The material is artificial stone, obtained by firing clay. There are other manufacturing methods. Based on the manufacturing method and composition, the following main types of brick are distinguished: red, silicate (white) and decorative.

The material is a rectangular block. Its main geometric parameters are height (thickness), width and length. All edges of such a block are used as workers. In this case, the following names are accepted: the widest side is bed, the side edge is spoons, the end edge is dots.

Red is most common in wall construction. It is obtained by firing clay. Standard red is available in sizes 120x250x65 mm. It has a division in compressive strength from 76 to 300 kg/cm² (this value is indicated in the grade of the material). The weight of one standard brick is 3.5-3.8 kg. In addition, a thick red one with dimensions of 120x250x88 mm is produced.

Silicate has a quartz-sand base. It comes in white. Standard sand-lime brick is the same size as thick red brick.

All types have very good frost resistance, heat resistance and high waterproofing properties. The mechanical strength of a material depends on its composition, therefore it is indicated in its brand, for example, M500 - compressive strength 500 kg/cm². When choosing, you should consider what surfaces it is intended for (load-bearing, internal, etc.). Frost resistance is also indicated in the brand after the letter F, for example, F50 is frost resistance of -50º C. Thermal insulation properties depend on the presence of voids: hollow bricks have higher thermal insulation characteristics, but reduced strength.

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Brick wall design

The work is a regular masonry bonded with a fastening agent (mortar). Reinforcing elements can be used for strengthening. The main indicators of any wall are strength and thermal insulation properties. In the case of a brick wall, these parameters depend (in addition to the properties of the brick itself) on the thickness of the floor and the method of laying in a row.

The thickness mainly depends on the number of rows in the transverse direction. The calculation is based on the condition of laying in one row on a bed across the wall. In this case, the following wall thicknesses are accepted:

Scheme of ligation and brickwork of walls: 1 - tie row, 2-6 - spoon rows.

• 125 mm – half a brick;
• 250 mm - 1 brick;
• 380 mm – 1.5 bricks;
• 510 mm – 2 bricks;
• 640 mm - 2.5 bricks.

Brick walls usually have the following thicknesses:

• external – 1.5-2 bricks;
• internal load-bearing – 1.5;
• partitions – 0.5.

The surface is made of bricks bound with mortar. The solution forms a seam between the touching faces. When laying, the solution is applied to all contacting faces. As a result, the following seams are present in the wall: on the front side there is a horizontal seam (between the beds of bricks) and a vertical seam (between the ends), inside the wall there is a longitudinal seam (between the spoons) and a transverse seam (between the surfaces interior bricks along the wall).

Cement-based mortars, lime mortars and cement-lime mortars can be used as a binding agent for fastening. Cement-based mortar is a mixture of cement and sand in a ratio of 1:3 or 1:4. Lime mortar (lime with sand and a small amount of clay) has low strength, but has good thermal insulation properties. The most common type of brick wall is cement-lime mortar. The approximate proportion of the mixture is as follows: cement - 1 part, sand - 3 parts, lime - 1 part.

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Basic rules of brickwork

Brick walls will have sufficient strength if certain rules for laying the material are followed.

First of all, the planes of all rows must be parallel to each other.

Standards prohibit surface distortion by an angle of more than 17°. The spoons and points inside the row should form two mutually perpendicular systems, that is, by contacting each other, form transverse and longitudinal seams. Longitudinal and transverse seams in the vertical direction must be parallel.

The laying principle should be based on the bonding principle, i.e. the brick should be placed on at least two lower bricks.

A similar dressing should be done along the vertical, longitudinal and transverse seams.

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Types of brickwork

Image 1. Types of brickwork.

Depending on the installation of the brick (along or across), two types of masonry are distinguished: bonded and spooned. With interlocking masonry, only the ends of the brick extend onto the front side of the wall, and with spoon masonry, only the side edge extends. Various combinations of these styling are possible.

With a thickness of half a brick, only spoon masonry is possible. In the case when the thickness is one brick, it is possible to use both methods, but a combination of these methods is preferable. For example, after 2-3 bricks are laid along the wall, one is laid across. This installation creates an interlacing in one row and strengthens the structure.

More more options combinations of installations can be used as the wall thickness increases. A brick wall made according to Old Russian masonry has the following combination of edges on its front side: alternating one poke and one spoon, with the poke falling in the middle of the spoon in the previous row (image 1: types of brickwork)

An important laying rule is the bandaging of joints, i.e. the joint between bricks in one row should not coincide with the joint in the previous row.

The third row is usually placed in the same way as the first row. Bandaging of rows should also be ensured in the transverse direction. Chain ligation involves alternating splice and spoon rows in order to prevent the seams from matching inside the wall.

Traditional wall material is brick- artificial building stone used for manual laying.
The most widespread in domestic construction is clay (red) brick. This brick resists the action well high temperatures, does not absorb moisture, and therefore was used without limitation in the walls and pillars of civil, public and industrial buildings.
Sand-lime brick It is distinguished by more regular shapes and precise dimensions and thus has a number of advantages in the production of masonry. However, it is more thermally conductive, less resistant to high temperatures and moisture-intensive.
Solutions for brickwork are composed of inert, lowering and various additives. The following are used as inert ones: ordinary (quartz) sand, sand from heavy boiler slag, sand from light and granulated slag, pumice sand, etc. The lower the density, the higher the thermal insulation properties of the solution and the lower the thermal conductivity of the masonry laid on it.
According to their structure, brick walls are divided into dense (homogeneous), made of brick, and lightweight, heterogeneous, made of brick with fillings made of other less thermally conductive materials or with air pockets.
Pre-revolutionary housing construction(until 1917) was formed by the construction of walls with massive brick walls 660-1480 mm thick. Excessive thickening of the walls was caused by the lack of calculation theory at that time stone structures. The thickness of the walls by floor was taken in relation to the developed practical rules, according to which the thickness of the walls of every two floors from top to bottom, starting from the third floor, increased by half a brick. The wall cuts were made inside the building.
The load-bearing capacity was used by 50-70%. The following types of solid masonry were most widespread at that time (Fig. 1):
. chain (spoon and butt rows alternate, the vertical seams of all spoon rows coincide);
. cross (vertical seams in spoon rows are laid out in a dressing);
. Dutch (bonded rows alternate with mixed ones; in a mixed row, spoon and interlocking bricks go through the mines);
. Gothic (consists of mixed rows, interlocking and tongue bricks alternate in each row);
. English (for every two spoon rows there is one bond row, all rows are tied in 1/4 brick).

Rice. 1. Types of brickwork:
a- chain; b- cross; v-Dutch; g - Gothic, d - English, f - multi-row, w - multi-row without bandaging the horizontal seams of the outer verst.

Pre-war housing construction was distinguished by the construction of buildings with both massive brick walls and lightweight ones.
Solid masonry was made of two types of ligation of seams: chain, which provides ligation of all seams in the cross section with overlying bricks, and American, which ensures ligation of seams in only one row of six; therefore it is often called six-row.
Lightweight walls. There is a relationship between thermal conductivity, self-weight and mechanical strength. The greater the dead weight, and therefore the density of the material, the lower its thermal resistance, but usually the higher its strength. This leads to the fact that in the walls of the upper floors there are excessive safety margins, and in the walls of the lower floors there is a lack of thermal resistance, which causes excessive weighting of the wall structures and foundations and loss of usable area premises.
Where there was a reserve of strength, so-called lightweight walls made of lighter and therefore less thermally conductive materials were used. This made it possible to reduce the thickness of the walls so that the strength of the material was maximally used. Such materials are types of bricks that have significantly less mass and lower thermal conductivity than ordinary clay or silicate, for example: 1) clay-tripel, obtained by firing clay with an admixture of tripol; 2) porous, during the production of which coal dust or sawdust is added to the clay, which burns out during firing; 3) non-firing - slag and ash, produced from granulated slag and oil shale ash.
The listed varieties of bricks have the same dimensions and shape as ordinary clay bricks, and are produced in the following grades: respectively, “35”, “50”, “75”, “100”; thus, on average, they are less durable than ordinary clay bricks.
Structurally lightweight brick masonry is no different from masonry made of ordinary brick, but the minimum thickness of the walls was reduced by 1/2 brick, since their thermal resistance is 30-50% higher (depending on the type of brick). Masonry from these types of bricks was carried out exclusively on light mortars of grades “8” and “15” and was used only for low-rise (2-3 floors) buildings or the upper floors of multi-storey buildings. The use of such bricks was not allowed for the walls of rooms with high humidity (baths, laundries), as well as for laying chimneys, hogs, stoves, etc.
A significant reduction in the mass of the wall was achieved by replacing part of the brickwork with other lightweight and therefore low thermal conductivity materials.
Masonry with backfill. One of the oldest wall designs of this type was proposed in the 90s. XIX century architect Gerard. The masonry of the Gerard system consists of two walls, each half a brick thick, laid out on a mortar grade of at least “15”, with a gap between them of 18-33 cm, filled with low thermal conductivity material: a backfill of boiler slag, ash, crushed coal, etc. or slag - sawdust concrete of composition 1:10:6 (lime paste: slag: sawdust). For areas with 1= -30°C, the wall thickness was taken to be 51 cm, for areas with a temperature of -400°C - 56-64 cm. To eliminate the risk of dampening of the backfill due to condensation of vapors penetrating from inside the premises, inner surface the walls were covered with dense (cement) plaster, oil paint etc. To connect the walls, they were connected to each other by releasing pokes - through one row from each wall. When leaving a gap of 3-5 cm wide between the poke and the wall, the danger of freezing along the line of the pokes can, as practice has shown, be considered eliminated. Connecting walls with metal brackets requires a significant amount of metal, complicates the work, and therefore was rarely used.
Backfills give some settlement over time, resulting in the formation of voids that reduce the thermal resistance of the wall. To combat this, a gap was left in the upper part of the walls, within the attic, through which the backfill was periodically replenished.
Compared to solid brick wall Guerard system more economical in terms of material consumption. However, it required the use of only good, intact bricks; in addition, laying such a wall is more labor-intensive than laying a solid wall.
These shortcomings were partially eliminated in N.S.’s masonry. Popova - N.M. Orlyankin, in which two low walls in four horizontal rows of trays were overlapped by horizontal diaphragms made of solid brickwork two rows thick. The low-height backfill resulted in virtually no settlement, and the masonry of the wall with horizontal diaphragms was simple.
Infill walls were used for the exterior walls of buildings no more than five stories high. The distance between the transverse walls or columns of the frame did not exceed 7.5 m. Such walls were not installed in buildings with high air humidity: laundries, baths, kitchens, washing rooms.
The plinth was built from solid masonry with appropriate thickening. The partitions had a width of at least 51 cm. The lintels with a span of up to 1.5 m were arranged in rows, separate under each wall. The backfill was supported by an antiseptic (creosoted) board laid over the window frame. The row lintels had a height of at least six rows and were laid out on a 1:4 cement mortar. Bundle iron was laid under the bottom row of bricks. Non-load-bearing lintels with a span of more than 1.5 m, as well as all lintels bearing the load from floor beams (regardless of the span), were reinforced concrete or made of rolled steel beams.
The floor beams rested on both walls through wooden or reinforced concrete pads. To increase the stability of load-bearing external walls, sometimes a reinforced concrete belt 6.5 cm thick was provided under the beams of the interfloor floor. In order not to rest the beams on the walls, internal pilasters were installed along which wall purlins were laid along the wall, supporting the ends of the beams.
Brick-concrete masonry and masonry filled with ready-made liners - masonry N.S. Popova. The masonry of this system consists, like those described above, of two parallel walls the thickness of a brick. The gap between them was filled with lightweight concrete (approximate composition 1:2:24 - cement: lime paste: slag).
With a density of lightweight concrete of 1250 kg/m3, the total wall thickness using a warm solution was taken in areas with a temperature of -20 degrees. at 42 cm, in areas with -30°C at 52 cm, and in areas with -40°C at 60 cm.
When masonry was less than 51 cm thick, to connect the walls with lightweight concrete, every fourth to sixth row in height was overlapped with studs in a checkerboard pattern.
When the thickness of the masonry was over 51 cm, the connection was carried out by a through horizontal row of brickwork, laid in height every three tray rows of the side walls.
Masonry N.S. Popova used for external walls up to 15 m high, i.e. for four-story buildings. By replacing the internal part of the masonry with lightweight concrete, savings of 20 to 40% of bricks were achieved without compromising the thermal properties.
The structure of the plinth and cornices was not fundamentally different from the structure of those with solid brick walls. The lintels over the openings were usually made of ordinary brick.
The advantage of brick-concrete walls is their high strength. This is explained by the fact that the concrete absorbs part of the load transmitted to the wall, and, in addition, the connection between the front walls is well ensured. Therefore, brick-concrete walls, depending on the grades of brick used and the class of concrete, were allowed to be built up to six floors.
The disadvantages of such walls are: insertion into the brick wall during laying large quantity moisture and increased labor intensity of work and difficulties in carrying out work in winter. These shortcomings are eliminated in the design of a brick wall with thermal liners developed by V.P. Nekrasov (Fig. 2). This wall differs from a brick-concrete wall in that its internal space, instead of a concrete mixture, was filled with pre-made low-thermal conductivity stones (thermal liners). For the manufacture of thermal liners, lightweight concrete, foam concrete, foam silicate, etc. were used.
Well masonry walls of the L.A. system Serka and S.A. Vlasova (Fig. 3, a, b, c) consists of two front walls with a thickness of 0.5 bricks, between which there are transverse half-brick walls (diaphragms), which provide a connection between the front walls and divide the internal cavity of the wall into a series of wells.

Rice. 2. Lightweight masonry with thermal liners: 1 - brickwork; 2 - thermal insert

The distance between the diaphragms was set from 530 to 1050 mm, i.e. from two to four bricks. The wells were filled with lightweight concrete or lightweight concrete liners. The walls were made with a thickness of 1.5 to 2.5 bricks, depending on the brand of brick and class of concrete. Well masonry walls were used in the construction of buildings up to five floors high. In buildings up to two floors inclusive (as well as in the upper two floors of multi-story buildings), wells were filled with slag. To avoid settling of the backfill, reinforced mortar diaphragms 15 mm thick were installed every five rows of brick along the height of the wall from a solution of the same composition as for the masonry (see Fig. 3, d).
Under the floor beams, the mortar diaphragms were thickened across the entire width of the wall to 40 mm and reinforced with additional reinforcement.
In corners and junctions interior walls to the outside they were reinforced with steel ties. Ties with a diameter of 5-6 mm with hooks at the ends were laid in mortar diaphragms at the levels of ceilings, window sills and lintels.
All described structures of lightweight walls, depending on the results of thermal engineering calculations, were made with a thickness of 380-420 mm (1.5 bricks), 510-580 mm (two bricks) or 640-700 mm (2.5 bricks). Intermediate thickness was obtained by widening the vertical joints between the interlocking bricks of the transverse walls.

Rice. 3. Well masonry wall of the L.A. system. Serka and S.A. Vlasova:
a - rows of masonry; b- sections along the well; c - section along the transverse wall; g - cross-section along the well when backfilling is installed; 1- bricks of a spoon row; 2- bricks of a bonded row; 3 - slag; 4 - thermal insert; 5 - solution diaphragm.

Walls with an air gap (proposal by G.F. Kuznetsov) consist of two walls with a gap between them (Fig. 4, a). The main internal wall has a thickness of 1 or 1.5 bricks, depending on the required strength and thermal requirements. The outer wall was laid out with a thickness of 0.5 bricks. A closed air layer 50 mm thick has a thermal resistance equivalent to the resistance of brickwork 0.5 brick thick. Therefore, the presence of such a layer in the masonry significantly saved brick and mortar and made it possible to reduce the thickness and weight of the wall without deteriorating its thermal properties.
The connection between the inner and outer walls was carried out by bonded rows of bricks placed every five rows of bricks, as a result of which such walls were allowedused in multi-storey construction. Walls with an air gap could be laid out of solid bricks, as well as hollow and porous ones. When using bricks with a height of more than 65 mm, transverse ligation was performed every four rows (see Fig. 4, a).

Rice. 4. Walls with an air gap:
a - made of solid brick; b-from multi-hole brick; c - filled with mineral felt; 1- air gap; 2 - external plaster; 3- internal plaster; 4 - mineral felt on a bitumen binder; 5 - stitching.

To avoid blowing through the outer wall, its surface was plastered. If the air gap was filled with inorganic backfill (slag, mineral wool, etc.), no plaster was used, and the seams were carefully unstitched.
An example of such filling with mineral felt on a bitumen binder is shown in Fig. 4, c. The disadvantage of this design is its increased labor intensity.
Walls with slab insulation consist of load-bearing masonry 1-2 bricks thick and an internal heat-insulating board (gypsum, gypsum slag, gypsum sawdust, foam concrete, fiberboard) (Fig. 5).
The slab insulation can fit tightly to the wall with a mortar fastening, but it was recommended to install it on a distance, that is, create an air gap 20-40 mm thick between the wall and the slabs, which provides additional insulation (see Fig. 5, 6).
The slabs within each floor rest on reinforced concrete floors or on brick wall outlets so that their settlement does not differ from the settlement of the brickwork.

Rice. 5. Walls with slab insulation and panel cladding: a - installation of insulation on a mortar; b - installation of insulation on site; 1- cement mortar; 2- insulation; 3- grout; 4 - jointing; 5 - air gap 20-40 mm.

The installation of the slabs was carried out using lime-gypsum mortar and gypsum beacons (slats) applied to the wall. The beacons were applied in regular rows, and their surface was made strictly vertical. The distance between the beacons was determined in such a way that the joints of the slabs were located at the beacons. The slabs were installed in rows, bandaging the seams and connecting them to the masonry with special fasteners.
The advantage of walls with slab insulation is that they did not perform internal plaster, limiting themselves to grouting their surfaces and seams.
A rational design for mid-rise residential buildings is wall construction insulated with large-size cladding panels. These panels were used only in the areas between windows. The installation of the panels was carried out immediately after the completion of the laying of the walls of the corresponding floor before the installation of the ceiling and partitions.
The panel was fastened to the walls with nails, which were driven into tarred plugs. Special attention walls made from warm solutions with slag additives obtained from burning coal with a high ash content (about 20%) deserve to be used. Light (warm) solutions, in which fine slag was used instead of ordinary sand, are inactive and strongly deformed when compressed. As a result, with the same brand of mortar, the strength of masonry using warm mortar is almost 30% less than the strength of masonry using regular mortar. It is also less durable and resistant to moisture, especially to strong soaking of the surface of a wall with a damaged plaster layer by precipitation, which leads to a significant decrease in the strength qualities of the masonry.