What is the name of a set of artificial walls? Architectural and structural elements of walls. General information about building structural systems
The main structural part of a building is the walls. The walls are bearing structures, according to calculations, having sufficient strength and stability under vertical and horizontal loads.
Wall is a vertical fence separating the room from external environment or from another room.
The walls are divided:
- depending on the load perception - on carriers, self-supporting And non-load-bearing;
- by type of material - stone, wood, walls made of local materials, as well as combined
In this article we will look at the main types of walls by type of material - wooden And stone.
Wooden walls
For the walls of low-rise buildings, wood is a traditional material. The most comfortable in terms of sanitary and hygienic requirements are paving walls And chopped walls from coniferous trees. Their disadvantages are sedimentary deformation in the first 1.5-2 years and low fire resistance.
Frame walls justified in the presence of lumber and effective insulation materials. Note that frame walls do not require massive foundations, unlike log walls, they do not cause post-construction deformations. Fire resistance and capitality frame walls increases when facing with brick.
Logs It is advisable to harvest in winter, since the wood is less susceptible to rotting and warping during drying. Wood moisture content should be 80-90%. Logs must be free of cracks, rot, and not affected by bark beetles and fungi. The quality of the material can be determined by hitting the butt of an ax; a clean and clear sound indicates good quality. Wooden houses build no more than two floors high.
By design wooden walls heated buildings are divided into chopped from logs or beams, frame, panel and frame-panel.
Chopped log walls
Characteristic
Chopped log walls They are a structure made of logs stacked on top of each other in horizontal rows and connected at the corners by notches. The thickness of the logs in the upper cut for the external walls of heated buildings located in the central zone of Russia is 22 cm, in the northern and north-eastern regions it is 24-26 cm. The diameter of the logs is chosen to be the same, with the difference between the upper and lower cuts not exceeding 3 cm.
Technology
Each row of logs in the wall is called crowning glory. The crowns, laid sequentially one on top of the other from the bottom to the top of the wall, form a frame. First lower crown called the frame, it is made 2-3 cm thicker than the other crowns.
The crowns are placed with their butts alternately in different directions and connected along the length by means of vertical ridge(Fig. 10), and the joints of the crowns are spaced apart along the height of the wall. The crowns are held together using grooved grooves and insert tenons measuring 25x50x120.
The crowns are stacked groove downwards, thereby eliminating the possibility of water flowing into it. Tow is placed in the grooves between the crowns to seal the seam and insulate it. Depending on climatic conditions, the width of the groove is taken from 12 to 15 cm.
Spikes placed every 1.5-2.0 m along the height of the log house in a checkerboard pattern, rectangular (8x2 cm) or round (3-4 cm) cross-section, 10-12 cm high. In the piers, spikes are placed in each crown, one above the other in quantity at least two and located 15-20 cm from the edges of the wall.
Within 1-2 years after construction, the log house gives a settlement amounting to 1/20 of its height, due to shrinkage of the wood and compaction of tow in the seams. Due to draft of the log house nests for tenons should exceed the height of the tenons by 10-20 mm, and gaps of 6-10 cm are left above the openings, which are filled with tow and covered with platbands.
Seams between logs to reduce airflow, caulk with tow for the first time immediately after the construction of the walls and a second time 1-2 years after the end of settlement. In the corners of the building, the crowns are matched with a notch with the remainder in the bowl or without the remainder - in the paw. With the method of joining the crowns in the corners into a paw, i.e. without any residue, less wood is consumed, so this method is more appropriate. In Fig. Figure 11 shows a section of a chopped log wall from the cornice to the foundation.
Advantages and disadvantages
Chopped log walls are highly durable and have good heat-protective qualities, at favorable conditions durability. Log processing and wall construction - labor-intensive process, requiring a large consumption of wood.
Cobblestone walls
Characteristic
Cobblestone walls erected from horizontally laid beams. The use of beams makes it possible to eliminate manual processing logs, cutting of corner joints, wall junctions and move on to mechanized preparation of wall elements.
Procurement of material
Bars for walls are prepared at the factory with all notches for mates and sockets for tenons. Compared to log houses, the labor intensity of constructing log houses is significantly less, and wood consumption is reduced. Unlike log walls, block walls are assembled immediately on ready-made foundations.
Technology
Section of beams for external walls, 150x150 mm and 180x180 mm are accepted. Depending on climatic conditions, for internal walls - 100x150 mm and 100x180 mm. The beams are laid on top of each other with resinous tow placed between them and the seams caulked. For better drainage of water from the horizontal seam between the beams, a 20x20 mm chamfer is removed from the upper edge of the front part of the beam.
Rows of beams are connected to each other cylindrical dowels with a diameter of 30 mm and a length of 60 mm, placing them at a distance of 1.5-2 m from one another. The crowns of the mating paving walls are at the same level and connect them at corners, junctions and sections in various ways. The conjugation of the corner and the junction of the walls using dowels is shown in Fig. 12 using spikes measuring 35x35 mm and 35x25 mm.
Protection of paving walls
Effective protection of paving walls from atmospheric influences is planking or brick cladding, which protects walls from moisture, increases thermal protection, reduces exposure to wind, and fire resistance increases with brick cladding of walls. Brick cladding must be installed with a gap from the paving walls at a distance of 5-7 cm, below and above brick cladding leave vents to ensure ventilation.
Frame walls
Advantages
Frame walls require less wood than log or block walls, are less labor-intensive, and therefore more economical.
The basis of the frame walls is carrier wooden frame , sheathed on both sides with sheet or molded materials. Frame walls, due to their lightness, are practically not subject to shrinkage, which allows them to be sheathed or covered immediately after construction.
Wall protection
Frame walls must be protected from atmospheric moisture by external cladding with overlapped vertical and horizontal joints and arranging drains from the protruding elements of the walls. Protection against water vapor is provided by installing a vapor barrier made of synthetic film, glassine, or using other types of vapor barrier, laying them between internal lining and insulation.
Technology
For frame manufacturing 50 mm thick boards are used for external and internal walls, as for rafters and beams. With a thickness of 50 mm, load-bearing wall posts are recommended to be used with a width of at least 100 mm.
Width of frame posts in external walls is determined by the calculated thickness of the insulation, depending on the efficiency of the insulation itself and the calculated temperature of the outside air. The supporting pillars of the frame are placed at a distance of 0.5 m, matching the dimensions of the window and doorways. The basement beams are placed at a distance of 0.5 m. Corner posts the frame is made of beams or composite boards, and ordinary ones are made of boards 50x100, or 60x120 mm.
Frame with inside sheathed with boards of any profile and section, plasterboard boards; typesetting, sheet wall panels and others finishing materials. On the outside, clapboard, siding, planks, thermal brick panels and other materials are used to cover the frame.
Insulation
Insulation of frame walls carried out using mineral and organic materials with a density of up to 500-600 kg/m³. Mineral, glass wool boards, polystyrene foam are effective modern insulation materials, because they are fire-resistant, lightweight, not susceptible to rotting, exposure and penetration of bacteria, fungi, and are not destroyed by rodents. Organic insulation materials are susceptible to destruction by rodents, are flammable, and subject to rotting; in addition, before backfilling, they must be treated with an antiseptic and mixed before use with a mineral binder - cement, lime, gypsum, then laid in a wet state in layers of 15-20 cm, compacting. This backfill dries within 4-5 weeks, so to fill the frame you should use pre-prepared slabs and blocks from lightweight concrete. The materials for backfilling are: pumice, sawdust, gilak, shavings, peat and others, which are significantly inferior in their properties to modern mineral insulation.
Panel walls
Advantages
Difference panel boards wooden houses from frame ones is that their main structural parts consist of enlarged panel elements, manufactured, as a rule, at the factory. The process of constructing panel houses comes down to installation at the construction site and finishing works. The construction of panel wooden houses reduces the labor intensity of work and ensures high installation rates.
Technology
In panel rooms wooden houses the basis of the walls is bottom harness made of wood antiseptic bars, laid on the base of the building and attached to it using anchor bolts. Wall panels are installed on the frame. Above wall panels fastened with an upper harness placed on them, on which it rests attic floor. Wall panels are made internal and external, which, in turn, are divided into blind, window and door. The height of the boards is equal to the height of the floor, the width is assumed to be 600-1200 mm. The panels consist of paving frames and sheathing, internal and external, between which insulation is placed.
Mattresses made from mineral felt. A vapor barrier is laid under the sheathing on the inside of the shield in order to prevent the formation of condensation of water vapor inside the shield penetrating into it from the side of the room. To reduce airflow under external cladding lay paper.
The panels are placed vertically and connected with nails. When making joints between panels, it is necessary to ensure sufficient density and airtightness of the joint. In Fig. 14b shows the recommended design of vertical joint of panels. The joint must be covered with continuous layers of air and vapor barrier.
Mineral felt 20 mm thick is placed in the joint, gluing it cold bitumen mastic. Then, using a lever device, the joint is compressed. IN panel houses the ceilings are made of panels or beams.
Wall protection
When installing the basement and cornice units, it is necessary to take measures to protect them from freezing by installing insulated base and an insulated frieze belt at the eaves, as well as from humidifying the internal air with vaporous moisture, arranging a vapor barrier for this purpose. Under basement floor The underground is not insulated. The underground should be cold and well ventilated, and the structure ceilings above the underground and especially the basement unit must have reliable insulation and vapor barrier laid on top under the finished floor structure. To protect against freezing, an insulated belt is installed outside at the ceiling level.
Stone walls
Homogeneous walls
Material
Homogeneous walls composed of ordinary hollow or light building bricks. In heterogeneous lightweight walls Part brickwork replaced the thickness of the wall with thermal insulation tiles and an air gap.
Technology
Walls are erected with a thickness of 1/2, 1, 11/2, 2, 21/2, 3 bricks or more, taking into account the thickness of the vertical joints equal to 10 mm; brick walls have a thickness of 120, 250, 380, 510, 640, 770, respectively mm or more. The thickness of the horizontal joints is assumed to be 12 mm, then the height of 13 rows of masonry should be 1 m.
When constructing brick walls, two masonry systems are used: two-row - chain and six-row spoon.
IN double-row masonry system Pod rows alternate with spoon rows. Transverse seams in this system overlap by 1/4 brick, and longitudinal seams by 1/2 brick (Fig. 16).
Six-row system involves alternating five spoon rows with one back row. In each spoon row, the transverse vertical seams are tied in half a brick, the longitudinal vertical seams formed by the spoons are tied in stitched rows through five spoon rows.
Masonry using a six-row system is simpler than using a two-row system. To reduce the air permeability of the walls, the facing seams of the masonry are sealed special tool, giving the seams the shape of a roller, fillet or triangle. This method is called jointing.
Flaws
The disadvantage of ordinary solid brick, clay or silicate, is its large volumetric weight and, therefore, large thermal conductivity.
Crowning cornices
Technology
Crowning cornice, shown in Fig. 17, brick masonry walls with a small offset - up to 300 mm and no more than 1/2 the thickness of the wall, can be laid out of brick by gradually releasing rows of masonry by 60-80 mm in each row. When the offset is more than 300 mm, the cornices are made from prefabricated reinforced concrete slabs, embedded in the walls.
The inner ends of reinforced concrete slabs are covered with prefabricated longitudinal reinforced concrete beams, which are attached to the masonry using steel anchors embedded in it, thereby ensuring the stability of the cornice.
Classification
Lightweight brick walls are divided into 2 groups. The first group includes structures consisting of two thin longitudinal brick walls, between which they lay thermal insulation material, the second group includes structures consisting of one brick wall, insulated with thermal insulation boards.
Brick walls with insulation from thermal insulation panels
Characteristic
Brick walls with insulation of thermal insulation panels (Fig. 19) consist of a load-bearing part - masonry, the thickness of which is determined only from the conditions of the strength and stability of the wall, and a heat-insulating part - foam concrete, gypsum or gypsum slag panels.
Advantages and disadvantages
Lightweight concrete stones compared to ordinary bricks, they have a lower volumetric weight and lower thermal conductivity, therefore the use ceramic stones for the construction of external walls allows you to reduce their thickness. The disadvantage is that lightweight concrete stones with a lower volumetric weight have less strength and resistance to weathering.
Characteristic
Three-hollow stones with large voids have dimensions of 390x190x188 mm. In bonded rows, a bonded stone with a smooth end surface is used.
After laying the stones into the wall, the void in climatic conditions the middle and northern regions should be filled with slag, a material with low thermal conductivity, since when the voids are large, air exchange occurs in them, increasing the thermal conductivity of the wall. Filling voids with low-conductivity materials increases the labor intensity of masonry. To reduce air circulation in voids, three-hollow stones with blind voids are used - five-walled stones.
The base is the layers of soil that lie under the foundation, as well as to the sides of it.
The base can be natural or artificial.
The thickness of soil lying under a building and receiving loads from it is called natural basis.
If the natural soil mass is not capable of absorbing the loads from the building being constructed and requires work to strengthen it, then such a foundation is called artificial.
Natural bases, their properties.
When constructing buildings on natural foundations:
Soils lying in the thickness of this base must have the necessary compressibility;
Soils must have sufficient bearing capacity;
Soils should not have heaving properties;
Soils must resist the effects of groundwater, which, by dissolving some rocks, removes the smallest particles from their thickness, resulting in porosity of the base, which reduces its bearing capacity;
Soil characteristics:
Rocky– in the form of a continuous or fractured massif of quartzites, limestones, sandstones, such soils are practically not compressible, are not subject to heaving and are excellent foundations.
Coarse clastic– in the form of layers of large stones and pebbles, these soils are slightly compressible, not heaving, waterproof and are good foundations.
Sandy– depending on the size of sand particles, soils are divided into: gravelly, coarse, medium, fine, dusty.
Gravelly, coarse and medium sands quickly compact under load, do not swell when freezing, and are strong and reliable. Fine and dusty sands, when increased and subsequently frozen, become heaving and their bearing capacity decreases.- in a dry and low-moisture state they are able to withstand loads on the building, but when moistened, the bearing capacity of these soils decreases;
such soils are characterized by long-term settlement under load and swelling when freezing; Loess-like
- in their natural state they have pores in the form of vertical tubes; in a dry state they have sufficient load-bearing capacity, but when moistened their structure is destroyed and under the influence of load they form subsidence; Artificial foundations. If the foundation soils within the compressible strata do not have the necessary bearing capacity (peaty bulk soils, loose sandy and loamy soils with a high content of organic residues, etc.), they are artificially strengthened or foundations are used that transfer loads to underlying strong soils, in particular , pile foundations. Choice pile foundations
or a method of strengthening soils is carried out by a technical and economic comparison of various options for constructing foundations and foundations.
In mass civil construction, as a rule, two types of artificial foundations are used: a foundation created by soil compaction, and a foundation created by its consolidation.
Foundations, their classification.
According to design diagrams:
strip, columnar, solid, pile;
according to the material:
natural stone, rubble concrete, concrete, reinforced concrete, metal, wood;
by nature of work:
rigid (working in compression) and flexible (working in compression and bending);
by depth:
shallow (up to 5 m) and deep (more than 5 m);
Strip foundations.
In the form of a continuous strip under the load-bearing walls of the building.
FL (reinforced concrete), length - 3000 mm, width - 1600 mm
FBS (concrete), block height – 580 mm (280 additional), width – 300, 400, 500, 600 mm
Seam – 20 mm
Columnar foundations.
It consists of a column support in which a glass for the column is placed, a slab part consisting of steps. (1,2,3) Pile and solid foundations. A solid foundation (in the form of a solid monolithic reinforced concrete slab) is installed under the entire area of the building; such foundations are erected under significant loads or weak and heterogeneous soils. They ensure uniform settlement of the building and protect
basement
from water back up.
A pile foundation consists of piles and a grillage.
Classification by nature of work:
by material: metal, wood and reinforced concrete.
according to design solutions:
Driven (manufactured at the enterprise, placed in the ground using mechanisms);
Prismatic (reinforced concrete, solid section, section size: 200x200 and 300x300, length: 4.5-12 m);
Prismatic (with a round plane, section size: 300x300, 250x250, length: 3-8 m);
Tubular (reinforced concrete, diameter: 400-800 mm, length: 4-12 m)
Wooden (from softwood logs);
Pyramidoidal (with an upper section of 300x300, inclined side faces up to 14°, length: 5-12 m);
Pressed (from monolithic concrete, laid in pre-drilled wells and connected on top by a grillage);
by depth:
short (3-6 m)
long (more than 6 m)
Electrical wiring is a set of insulated wires and cables with their fastening elements, protective and supporting structures.
Electrical wiring ensures the supply of electricity to consumer electrical receivers. When designing electrical wiring, you should be guided by the current “Rules for the Construction of Electrical Installations” (PUE), “Norms for the Technological Design of Electrical Installations” and “Building Norms and Rules” (SNiP).
Internal and external electrical wiring
Internal wiring is electrical wiring installed indoors.
External wiring is called wiring laid along the outer walls of buildings and structures, under canopies, etc., as well as between buildings on supports (no more than four spans of 25 m each) outside streets and roads.
Open and hidden electrical wiring
TO open wiring This includes wiring laid on the surface of walls, ceilings, supports, trusses and other construction elements of buildings and structures. Wires and cables are laid directly on the surface of walls, ceilings, on rollers, insulators, on cables, on brackets, in pipes, in flexible metal sleeves, or directly by gluing to the surface.
Open electrical wiring can be stationary, mobile and portable. Open electrical wiring includes wiring laid inside the structural elements of buildings and structures (in walls, floors, ceilings), as well as in plastered grooves, without grooves under a layer of wet plaster, in closed channels and voids building structures etc.
Wires and cables are laid either in pipes, flexible metal sleeves, boxes, or without them.
Hidden electrical wiring completely protects wires and cables from mechanical damage and environmental influences.
Replaceable and non-replaceable electrical wiring
Hidden electrical wiring can be replaceable or non-replaceable.
Replaceable wiring is the type of wiring that allows you to replace wires during operation without destroying building structures. In this case, the wires are laid in pipes or channels of building structures.
Fixed wiring cannot be dismantled without destroying structures or plaster.
- designing electrical wiring in a garden house, cottage or residential building begins with drawing electrical diagram connections linked to the floor plan of the house on a scale of 1:100 (1:200);
- electrical wiring on the plan is drawn in a single-line design. Lamps, switches, sockets, and protection devices are indicated on the plan drawings by conventional symbols.
In different climatic zones of the country, a variety of materials are used in the construction of garden houses, cottages and dachas. Construction Materials and designs. All erected buildings are divided into three categories:
- according to the degree of flammability of building materials and structures;
- according to environmental conditions;
- according to the degree of electric shock.
In accordance with the requirements of the “Building Codes and Rules”, all building materials and structures are divided into three groups: combustible, non-combustible and non-combustible.
- fireproof includes all natural and artificial inorganic materials used in construction; metals, gypsum and gypsum fiber boards with an organic matter content of up to 8% by weight; mineral wool slabs on a synthetic, starch or bitumen binder with a content of up to 6% by weight;
- Refractory materials include materials consisting of non-combustible and combustible components, for example, asphalt concrete, gypsum and concrete materials containing more than 8% by weight of organic filler; mineral wool slabs on a bitumen binder with a content of 7-15%; clay-straw materials with a density of at least 900 kg/m³; wood subjected to deep impregnation with fire retardants, fiberboard, textolite, and other polymer materials;
- All other organic materials are classified as combustible.
The "Rules for the Construction of Electrical Installations" (PUE) adopt the following environmental conditions:
- Dry: relative humidity in them does not exceed 60%. These are residential heated premises.
- Humid: here the relative humidity does not exceed 75%, vapors or condensing moisture are released only temporarily and in small quantities ( unheated premises, canopies of residential buildings, warehouses, sheds, utility rooms, kitchens, etc.).
- Raw: their relative humidity exceeds 75% for a long time.
- Particularly damp: here the relative humidity is close to 100%. The ceiling, walls, floor and objects in the room are covered with moisture (bathrooms, shower rooms, toilets, basements, vegetable stores, greenhouses, etc.).
- Hot: the temperature exceeds 30°C for a long time (steam rooms, baths, attics, etc.).
- Dusty: they may release abundant process dust in such quantities that it can settle on wires and penetrate into electrical equipment.
- Premises with a chemically active environment: here, due to production conditions, vapors are constantly or for a long time contained or deposits are formed that have a destructive effect on the insulation and live parts of electrical equipment (rooms for livestock and poultry, etc.).
- Explosive rooms and outdoor installations: explosive mixtures of flammable gases or vapors with air or other oxidizing gases, as well as combustible dusts and fibers with air (garages, gas and oil product storage facilities, etc.) can form in them.
Wires and cables
In order to save scarce wires with copper conductors, wires and cables with mainly aluminum conductors are currently used for electrical wiring.
Copper wires and cables are laid only in cases stipulated by the “Rules for the Construction and Operation of Electrical Installations”, for example, in fire and explosive premises, in buildings with combustible floors.
The laying of wires and cables with aluminum conductors is, in principle, no different from the laying of wires and cables with copper conductors, but is carried out with greater care in order to avoid damage to the conductors due to their smaller size. mechanical strength compared to copper. Working with aluminum wires, you should not allow multiple bends in the same place, or cuts in the cores when stripping the insulation.
A wire is one uninsulated or one or more insulated metal current-carrying core, on top of which, depending on the installation and operating conditions, there may be a non-metallic sheath, winding or braiding with fibrous materials.
Wires can be bare and insulated.
Bare wires are those that do not have protective or insulating coatings on top of the current-carrying cores. Bare wires of brands PSO, PS, A, AS, etc. are usually used for air lines power transmission
Isolated are called wires in which the current-carrying cores are covered with insulation, and on top of the insulation there is a braid of cotton yarn or a sheath of rubber, plastic or metal tape. Insulated wires are divided into protected and unprotected.
Protected are called insulated wires, having a shell on top of the electrical insulation designed to seal and protect from external climatic influences. These include wires of the brands APRN, PRVD, APRF, etc.
Unprotected are insulated wires that do not have a protective sheath over the electrical insulation (wires of the APRTO, PRD, APPR, APPV, PPV brands, etc.)
A cord is a wire consisting of two or more insulated flexible or especially flexible conductors with a cross-section of up to 1.5 mm², twisted or laid parallel, covered with a protective insulating sheath.
A cable is one or more insulated cores twisted together and enclosed in a common rubber, plastic, or metal sheath (NVG, KG, AVVG, etc.).
For electrical wiring of power and lighting networks carried out inside garden houses and cottages, as well as on the territory garden plots, insulated installation wires and non-armored power cables with rubber or plastic insulation in a metal, rubber or plastic sheath with a cross-section of phase conductors up to 16 mm².
The conductive cores of the installation wires have standard cross-sections in mm: 0.35; 0.5; 0.75; 1.0; 1.5; 2.5; 4.0; 6.0; 10.0; 16.0, etc. The wire cross-section is calculated using the following formula:
S = ?D 2: 4
where S is the wire cross-section, mm²;
n - number equal to 3.14;
D - wire diameter, mm.
The diameter of the current-carrying core (without insulation) is measured with a caliper or micrometer. The cross-section of the cores of stranded wires is determined by the sum of the cross-sections of all wires included in the core.
The insulation of the installation wires is designed for a certain operating voltage. Therefore, when choosing a wire brand, it should be taken into account that the operating voltage for which the wire insulation is designed must be greater than the supply voltage electrical network. The network voltage is standardized: - 380 V, phase - 220 V, and installation wires are available for a rated voltage of 380 V and higher, therefore, as a rule, they are suitable for electrical wiring.
The installation wires must match the load being connected. For the same brand and the same cross-section of wire, loads of different magnitudes are allowed, which depend on the laying conditions. For example, wires or cables laid openly are cooled better than those laid in pipes or hidden under plaster. Wires with rubber insulation allow long-term heating of their cores, not exceeding 65°C, and wires with plastic insulation - 70°C.
The cross-section of the current-carrying conductors is selected based on the maximum permissible heating of the conductors, at which the insulation of the wires is not damaged.
General information about structural systems buildings
SECTION 2.1. BUILDING STRUCTURAL SYSTEMS
Ensuring spatial rigidity of buildings.
The building and its elements must have:
Strength - ability to withstand loads
Stability - the ability of a building to resist horizontal loads
Spatial rigidity is the ability of individual elements and the entire building not to deform under the action of applied forces.
In frameless buildings, spatial rigidity is ensured by the device:
Internal cross walls and walls stairwells associated with longitudinal (external) walls
Interfloor enterprises connecting the stand to each other In frame buildings with a device
Multi-tiered frames formed by a combination of columns, crossbars and ceilings, representing a geometrically unchangeable system.
Shear walls installed between columns
Walls of staircases and elevator shafts related to frame structures
Ground mating of frame elements at joints and nodes.
The structural system of a building is a set of vertical and horizontal load-bearing structural elements, interconnected in a certain way and ensuring the strength and stability of the building.
Structural elements of a building (foundations, walls, individual supports, floors) that absorb all types of loads arising in the building and acting on it from the outside, and transmitting these loads to the foundation soils are called load-bearing frame of the building. Depending on the combination of elements forming the load-bearing frame, the following structural systems of buildings are distinguished:
Frameless with load-bearing walls (wall);
Frame;
With an incomplete frame (combined).
Constructive decisions elements and systems of the building as a whole are selected on the basis of variant design and technical and economic analysis of their main technical and economic indicators.
Frameless system is a system that combines external and internal walls and floor slabs resting on them into a single load-bearing frame. The frameless system, in turn, is divided into:
A system with longitudinal walls located along the long facade side of the building and parallel to it (there can be two, three, four) (Fig. 2.1);
A system with transverse load-bearing walls, with a narrow pitch (4.2 - 4.8 m), with a wide pitch (more than 4.8 m), with mixed steps (Fig. 2.2);
System with longitudinal and transverse walls (cross-wall with simultaneous support of floor panels along the contour). The size of the floor panels in this case equal to size spatial cell between four walls (Fig. 2.3).
In buildings with a frameless system, external load-bearing walls combine two functions: load-bearing and enclosing.
Rice. 2.1. Building with longitudinal load-bearing walls:
A - axonometry; B - floor plan; B - floor plan; 1 - floor slab; 2 – external load-bearing wall; 3- internal longitudinal load-bearing wall; 4 – transverse self-supporting wall
Rice. 2.2. Building with transverse load-bearing walls:
A - axonometry; B - floor plan; B - floor plan; 1-floor slab; 2 – external load-bearing wall; 3- internal longitudinal load-bearing wall; 4 – external longitudinal self-supporting wall
Rice. 2.3. A building with longitudinal and transverse load-bearing walls at the same time (supporting floor panels along the contour):
A - axonometry; B - floor plan; B - floor plan; 1- floor panel; 2 - external longitudinal load-bearing wall; 3 - external transverse load-bearing wall; 4- internal transverse load-bearing wall; 5- internal longitudinal load-bearing wall
All buildings, despite their differences in technical design, consist of separate structural parts. Walls are one of them. I propose to consider the architectural and structural elements of the walls, get acquainted with their name and purpose.
When designing buildings, they also take into account aesthetic considerations, giving the facade a look with attractive proportions of the external elements of the building walls.
To avoid solidity (uniformity), the surfaces are conventionally divided vertically (pilasters, for example, braces) and horizontally (plinths, cornices).
Basic wall elements
Base
The lower part of the building (walls), located on the foundation, slightly protruding beyond the plane of the facade, is called the plinth. It connects the foundation to the walls.
The top of the plinth (cordon) is arranged horizontally, so a building with a high plinth (50-60cm) is perceived as architecturally complete, rising as if on a pedestal. In addition to architectural and constructive expressiveness, the plinth protects the building from the penetration of precipitation.
Waterproofing is installed between the foundation and the plinth to prevent moisture from entering the masonry. IN in some cases, when the material of the walls and base is different, then waterproofing layer They are also provided on top of the base.
For non-seismic areas - this is roll waterproofing (roofing felt, modern rolled materials). For a seismic zone - this is waterproofing from cement mortar M – 100, 150, 30mm thick.
The plinth is an important architectural and structural element, forming the foundation of the structure; it gives it not only visual, but also structural stability. It must be finished with durable, waterproof and frost-resistant materials.
It can be:
- Plaster with granite additives, marble chips, just plaster;
- Brick cladding with jointing;
- Natural or artificial stone;
- Natural cladding, artificial tiles and other options.
1-base; 2-window opening; 3 - doorway; 4-jumpers; 5- ordinary pier; 6 — corner pier; 7- crowning cornice; 8 same, intermediate; 9- belt; 10 - sandrik; 11-parapet; 12 – pediment; 13- niche; 14 – pilaster; 15- buttress; 16-cut; 17 – bracing Architectural and structural elements of walls give the building proportionality in shape and size, improving the visual perception of the structure as a whole.
Openings
Openings are large holes left during the construction of walls for windows, door blocks, and stoves. The distance between the openings is called piers.
Types of piers:
- ordinary - between adjacent openings;
- corner - between the corner of the building and the nearby opening.
The upper and side areas surrounding the opening are called slopes (lintel). In brick external walls, the masonry in the openings is arranged with projections of a quarter of a brick (from the street side).
Jumpers
The structure that covers door, window, and arched openings is called a lintel. The lintels support the walls and ceilings located above. They must rest on the wall masonry.
By bearing capacity jumpers are divided:
- Load-bearing elements - must bear the weight load wall material above it, the ceiling plus its own weight;
- Non-bearing - only their own weight and the load from the wall material above them.
More common in construction are prefabricated reinforced concrete products, the dimensions of which are taken depending on the load, the size of the space to be covered, and the thickness of the walls on which it will rest. Monolithic lintels are not practical in terms of cost and labor intensity, but are possible.
The embedment depth is:
- for load-bearing – 250mm;
- for non-load-bearing elements - at least 125mm;
- for partitions – 200mm.
They are mounted on a layer of mortar no more than 15 mm thick. The geometric shape of the lintel can be bar, slab, façade or beam. If they overlap a non-standard size in width, then it is made according to an individually placed order.
Architectural and structural elements of walls - in particular, lintels can be arranged and brick type provided that the width of the space to be covered is no more than 2 meters, with a small load from the wall material laid above, in non-seismic areas, in the absence of vibration. They are used only in non-load-bearing walls.
Brick lintels, depending on the masonry technique, are:
- Ordinary lintels - the masonry is of the usual type, like a continuous belt, the mortar is of a higher grade, and special quality control is carried out. The height of the masonry layer is calculated by the project, and should not be less than four rows.
When installing a lintel, formwork is installed at the bottom of it, on which a layer of cement mortar 30 mm thick is laid. Reinforcement is recessed into this layer, the cross-section and number of rods of which is determined by the design. - Arched lintels are laid out on arranged formwork, made in the form of an arc of a given curvature. The brick is laid on edge. In this case, the seams between adjacent bricks are wedge-shaped. The number of rows of masonry must be kept odd.
They are now rarely used, mostly to give the building architectural and constructive expressiveness. They are mainly present in old buildings.
Cornices
Cornices are horizontal protruding parts of the wall. The main or crowning one is the upper cornice. It is considered as one of the main elements of the external walls, completing the architectural and structural ensemble of the building. Functionally, it serves to remove precipitation from the roof.
Architectural and structural elements of walls - cornices - are designed taking into account the size of the building, number of floors, accessory and harmony with the main buildings around.
As a rule, reinforced concrete prefabricated elements are installed, which are secured with anchors. If a small overhang of the cornice is provided, then it is made of brick by overlapping masonry (solid brick).
Cornices over openings (windows, doors) are called sandriks. The plane of the facades can be divided by additional, intermediate cornices of simple shape - belts.
Expansion joints in the walls of a building
If the building is long, its parts may not react equally to external influence. These are temperature changes, uneven settlement, seismic vibrations, which can lead to the appearance of cracks that reduce the load-bearing capacity of the structure.
Expansion joints divide the building into separate parts from the foundation to the roof. Their width is calculated based on temperature winter period, brands of mortars, wall materials. For example, the lower the temperature in winter, the more often seams are made.
Settlement seams are performed where uneven settlement is expected. At the border of soils of different structure, at the junction of buildings with different number of storeys, and other similar options. Here the cutting is made from the bottom of the foundation.
Anti-seismic seams are provided in areas of increased seismicity on the principle that each individual compartment must be resistant to tremors.
Ventilation ducts
Smoke and ventilation ducts. They are made of brick and can be made of reinforced concrete (ventilation). They are designed for air exchange in rooms with high humidity, with the presence of combustion products, intoxication, and other similar situations.
According to the standards, a separate exhaust duct is provided from each room. The ducts should not communicate with each other, and the exhaust occurs to the street through ventilation heads on the roof.
Loggia, balcony, bay window
These are also architectural and structural elements of walls, providing additional usable area and operational amenities. They serve for economic needs, they can be attached to the room where they are located.
Balcony is a cantilever reinforced concrete slab anchored in outer wall. It is fenced with railings, the balconies are glazed and finished from the inside to prevent the access of precipitation, or can remain open.
Some owners of second floors that do not have a balcony arrange them themselves, resting them on racks, but this requires special permission and a design that calculates the loads on the supporting parts.
Loggia fenced on the sides with walls and a ceiling on top. The walls rest on a foundation made specifically for the enclosing walls of the loggia. Its load-bearing capacity exceeds that of a balcony. It can also be glazed and make an excellent utility room.
Bay window protrudes beyond the plane of the wall, increasing the internal space from the inside. It is glazed and connected to interior space. This is typical especially in houses of old construction with architectural and structural external forms. In plan form, it can be of different configurations depending on the architectural and structural solution.
Parapet
External walls quite often end with a parapet, which is a continuation of the masonry and rises above the roof. It is intended for fencing the roof; according to the architectural and structural design, it is a rectangular wall with a height of 0.7 - 1 meter. The parapet also serves architectural detail decorating the building.
Other description of wall elements
There are other smaller architectural and structural elements of walls. These include:
Gable- wall covering attic space on gable roof from the end, framed by cornices protruding beyond the plane.
Tong the same pediment, only without a cornice in the lower part at the base.
Niches- a blind recess in the walls. Heating radiators are recessed in them, built-in wardrobes, plumbing, etc. are installed.
Nests– small holes or recesses intended for laying pipelines in sleeves, sealing the ends of structures, etc.
Pilasters– narrow vertically located protrusions of the walls, used for their local strengthening with a large length or height, with rectangular cross-section in respect of. They can have a foundation, base, capital, which visually resemble columns.
Similar semicircular protrusions are called semi-columns. Pilasters and half-columns give the building aesthetic solemnity and monumentality.
Buttresses- structures that increase the stability of walls, which are protrusions from them with an inclined outer edge. This design provides additional rigidity and strength when absorbing horizontal loads.
Walls are sometimes made with ledges along the height of the masonry, which are called sawn-off shotguns. The ledges on the plane of the facades along its length are called unfastening.
All architectural and structural elements of the walls have their own functional purpose, and also give the building architectural beauty, expressiveness, and individuality.
