Prefabricated monolithic frame. Reinforced concrete frame of multi-storey buildings. Large panel walls

Monolithic house frame

An example of a constructed monolithic frame
Houses. Click on photo to enlarge.

Building a private house based on a monolithic reinforced concrete frame is an almost ideal way to build a house. The foundation, bearing columns and ceilings are made of reinforced concrete, and the walls are filled with masonry from blocks. The house is super strong; in fact, the same technology is used in the construction of modern skyscrapers. If a basement floor is planned in the house, then it is also made of monolithic reinforced concrete.

Building a house based on a monolithic frame allows you to implement any planning ideas. You can make rooms of different sizes, heights and shapes. You may not be attached to standard sizes concrete products (floor slabs). In too large rooms, load-bearing columns may appear on the "territory" of the room, this is inevitable.

A concrete frame is rarely built "by hand", using non-professional labor. Usually they hire a normal construction company. Concrete, of course, is also used purchased. An electric vibrator is used to compact the concrete mixture after pouring.

IN monolithic construction concrete works can be performed at a time, when the entire concrete structure is poured, or in stages, when the concrete is poured in parts. It is clear that it is impossible to fill in the two-story frame of the house entirely at once. Therefore, concrete is poured in stages, as the previous part of the structure hardens: for example, load-bearing columns on the second floor are poured after solidification of the monolithic between the first and second floors.

At this point, the concept cold seam. The temperature has nothing to do with it, the cold joint is the boundary between the hardened concrete and a new batch of freshly poured concrete. Unfortunately, the cold joint is a weak point in the concrete frame of the house, the adhesion of concrete here is worse than in just single-monolithic concrete.

But you don't have to worry too much about this. The appearance of cold joints is inevitable during the construction of a monolithic concrete frame of a house. Therefore, in order to improve the adhesion of hardened concrete to fresh concrete, the surface of hardened concrete must be cleaned of dust, dirt, water, and also the cement film that has arisen due to the presence of salts.

Monolithic floors are made using horizontally exposed formwork (for example, from moisture-resistant plywood) mounted on a set of vertical metal jacks. A reinforcing cage is knitted on the formwork, which is then poured with concrete. Supporting racks from under the ceiling are removed gradually, as the concrete sets.

Technological openings must be provided in the ceiling: for the chimney, ventilation ducts, cables, sewer pipes, water and heating.

In the construction of load-bearing columns, in contrast to floors, concrete with a higher mobility. The reason is the more abundant reinforcement of the columns, and the concrete must fill all the voids in the volume. Mobility should not be achieved by excessive addition of water. Mobile concrete mixtures are designated P1, P2, P3, P4, etc.

For monolithic columns, a special removable reusable formwork is usually used. There is no need to save here, otherwise the formwork can be torn apart by pressure from the inside. Normal construction companies have such formwork, although its use is not cheap. People who pour the bearing columns themselves are forced to build very strong formwork for the columns. Sometimes they build a "fixed formwork" of brick.

It is important to pour the entire column at once in order to avoid the appearance of a cold joint in the column. It will appear only at the junction of the column and floors. The cold seam of the column must be horizontal.

Concrete work is very desirable to carry out at a positive temperature. There are concrete additives to work with it in cold weather, and heating cables are sometimes used. You can also build a tent from a plastic film over a construction site, but it is still better to work with concrete if possible in the warm season.

The wall filler in a monolithic frame does not have to be very strong, because the load is carried by reinforced concrete columns. The wall in this case only performs a limiting and heat-shielding function. In fact, you can fill the walls in the monolithic frame of the house with any material: warm ceramics, ordinary bricks, blocks of cellular concrete (foam concrete, aerated concrete, etc.), wood concrete, etc.

You can use combinations of wall materials. For example, facing brick outside, warm ceramics inside. Or the option is more expensive: facing brick + warm ceramics + inner layer of ordinary ordinary brick. The third inner layer of brick in this case is needed for comfortable use of the wall: it is convenient to ditch, drill, fasten, nothing is guaranteed to fall out of the wall.

At houses based on a monolithic reinforced concrete frame, they can freeze monolithic floors if they go outside and are not insulated. The thermal conductivity of reinforced concrete is approximately 1.69 W / (m ° C), and this is a strong cold bridge inside the house. Therefore, all the ends of the floors must be insulated.

The columns of the monolithic frame must be "placed" against the inside of the wall. The slab extends beyond the column and the wall material "bypasses" the column from the outside. Thus, the bearing columns are constantly in the heat zone and do not freeze in winter. This prolongs the life of the columns, although it is already very long.

The place in the outer wall where the load-bearing column is located can turn out to be with poor heat transfer resistance. Therefore, it is possible that insulation will have to be used on this section of the wall.

Although the column must be pressed against the inside of the wall, it is not necessary to make the same even surface, the column should be slightly recessed inward. Thanks to this, if the walls are then chased, the strobes will not go along the column.

As one architect told me, there is a risk of moisture being sucked in by a monolithic concrete frame from a concrete foundation. In this case, it is necessary to separate the frame from the foundation with waterproofing. Those. the frame will stand on the foundation on the waterproofing layer. The fact that there is no direct integral connection between the foundation and the frame should not be afraid, gravity holds everything tightly. The house is already super strong.

Houses on a monolithic frame are well suited for earthquake-prone regions of Russia (Sochi, Yekaterinburg and other areas).

Igor (15.12.2015 11:36) I do not understand those who "steam" about the "high cost and complexity" of the reinforced concrete frame. In aerated concrete - foam concrete walls, under the ceiling, monolithic armored belts are arranged in without fail, you just need to add columns and here it is - the frame (simplified) is almost ready .... And this time you get a house of a completely different quality, which is not afraid of very strong earthquakes, soil subsidence .... in case of a strong fire - a frame will hold the ceilings (reinforced concrete) and allow you to safely evacuate .... Has anyone seen the cracked walls of an aerated concrete house (sometimes you can stick your fist into them)? Such a house becomes unsuitable (unsafe) for living and the money spent on its construction can be largely considered lost, plus the cost of dismantling .... Yes, such cases are not massive, but who will guarantee that the "saved" on the columns will not come back to haunt you .... The British are right in this regard (although I don’t like them) - your house should be a fortress))))

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Reinforced concrete frames of buildings and structures

Frameworks one-story buildings. frame elements. The main elements of the reinforced concrete prefabricated frame of one-story industrial buildings: foundations, foundation beams (rand beams), columns, crane beams, bearing elements of the coating (trusses, beams) and connections.

All elements of prefabricated reinforced concrete frames are unified. The characteristics of each of them are given in special catalogs. To connect prefabricated reinforced concrete frame elements to each other, as well as to fasten walls, coatings and other elements of buildings, they have embedded steel parts.

Rice. 49. General view of the precast concrete frame: 1-column; 2 - crane beam; 3 - farm; 4- coating slabs; 5 - steel frame of the lantern; connections

For slinging frame elements during their transportation, storage and installation during the manufacturing process, mounting (lifting) loops made of mild reinforcing steel (class A-1) are laid in them or special holes are arranged. The assembly of reinforced concrete elements into the frame is carried out by welding steel embedded parts. On fig. 49 brought general form prefabricated reinforced concrete frame of a one-story industrial building.

Foundations. Separate stepped reinforced concrete foundations are arranged under the columns of the building frame, having a glass in the upper part, in which the columns are installed (Fig. 50). For the arrangement of these foundations, see § 24. foundation beams. In industrial frame buildings with a column pitch of 6 and 12 m, foundation beams serve to support self-supporting walls on them and transfer loads from them to foundations. The beams have a T-shaped (Fig. 51) or trapezoidal cross section. The length of the main beams with a column pitch of 6 m is 4950 mm, with a pitch of 12 m - 10700 mm.

Rice. 50. Supporting the column on the foundation: 1 - column; 2 - foundation

Rice. 51. Foundation beam

Beams laid at the ends of the building and expansion joints, where the column spacing is reduced, are 500 mm shorter than the main ones - 4450 and 10 200 mm. The thickness of the beams for brick walls is 250, 380 and 510 mm, block -380 and 510 mm, panel -200, 240, 300 and 400 mm. The height of the foundation beams is 400 and 600 mm.

Beams 6 m long are made without prestressing, 12 m long - prestressed.

Rice. 52. Supporting the foundation beam: 1 - foundation beam; 2 - concrete column; 3 - foundation

Under the outer walls, the beams are laid on the outside of the column, under internal walls- between columns on the longitudinal center line. The beams rest directly on the steps of the foundations or on concrete columns (Fig. 52), laid out along these steps so that the upper edge of the beams is located at -0.030, i.e. 30 mm below the level of the finished floor. The gaps between the ends of the beams, as well as between the ends of the beams and columns, are filled with concrete grade 100.

On the leveled surface of the beams, horizontal waterproofing of the walls is arranged. In order to avoid deformation of the beams in heaving (clay) soils, as well as to protect the near-wall strip of the floor from freezing from below and from the sides of the foundation beams, slag bedding is made.

The foundation beams are made of concrete grades 200-400, the working reinforcement of the FB beams is made of steel class A-P, FBN beams (stressed foundation beams) - made of steel class A-Sh V.

Columns. In one-story industrial buildings, prefabricated reinforced concrete columns use solid rectangular sections (Fig. 53, a, b) and through two-branched (Fig. 53, c). In buildings equipped with overhead cranes, the columns have consoles for supporting crane beams on them, on which rails are laid to move the crane. Unified columns have a height that is a multiple of the module 600 mm. The design height of the column (H) is calculated from the level of the finished floor of the room, i.e. from the mark 0, 000 to the top of the column, excluding its lower end 900-1350 mm long, which is embedded in the foundation.

Rice. 53. Types of prefabricated reinforced concrete columns of one-story industrial buildings: a - for craneless buildings; b-crane of rectangular section; c - crane two-branch for middle rows

The part of the column, located above the consoles, is called over-crane, below - under-crane. The overhead part of the column, which supports the elements of the coating, is called the overhead column. In two-branch columns, the over-column is made from one branch, as a result of which ledges are created to protect the crane beams. The upper end of the column has a steel embedded sheet with anchor bolts for fastening the load-bearing elements of the coating. Steel embedded parts are also provided in the places of installation of crane beams and ties and, in addition, in the side planes of the extreme columns (for fixing walls).

To align the position of the columns during their installation, risks are provided in the form of vertical grooves of a triangular profile. They are applied on the four faces of the columns (top and bottom), as well as on the side faces of the consoles of the columns.

The columns are made of concrete grades 200, 300 and 400, the working reinforcement is made of A-Sh class steel.

Half-timbered (auxiliary frame) columns are arranged in end half-timbered and half-timbered longitudinal walls of one-story industrial buildings with a wall panel length of 6 and 12 m.

The columns rely on the load from the wind and the mass of the panel walls. install columns on independent foundations. The outer face of the columns is located in the plane inner surface walls.

The columns are made of concrete of grades 200-400, the working reinforcement is made of steel of class A-Sh.

Rice. 54. Prefabricated reinforced concrete crane beams: a - T-section 6 m long b - I-section 12 m long

Crane beams serve to move overhead cranes along them and are longitudinal links between the frame columns. Beams are installed on reinforced concrete columns at their pitch of 6 and 12 m. Crane beams have a T-section or an I-section. Beams with a span of 6 m are made of a T-section with thickening of the wall on supports 800 and 1000 mm high (Fig. 54, a), and with a span of 12 m - an I-section 1400 mm high with a reinforced upper shelf (Fig. 54, b). The upper flanges of the beams serve mainly for attaching crane rails to them. Beams are provided with embedded parts necessary for attaching beams to columns and rail tracks to beams. All beams are prestressed.

The beams are made of concrete grade 300-500, the working reinforcement is made of high-strength wire Vr-P, steel class A-Shv, etc.

Rafter beams. They are made single-slope, gable and with parallel belts (Fig. 55).

Shed beams (Fig. 55, a) are used in the coatings of one-story industrial buildings with a span of 6-12 m, with a column spacing of 6 m and an external drain. Gable beams (Fig. 55, b) are used in the coatings of one-story industrial buildings with spans of 6-18 m, column spacing of 6 and 12 m with external and internal drains. Beams with parallel belts (Fig. 55, c) are used in coatings of industrial buildings with flat roof with spans of 12 and 18 columns of 6 and 12 m. Rafter beams have a T- or I-section. In order to reduce the mass of beams and pass communications in their walls, holes of various shapes are arranged. Single and gable beams can be assembled from separate blocks with subsequent tension of the reinforcement passed through them.

Beams are installed on reinforced concrete columns or on load-bearing walls with reinforced concrete pads, and beams with a span of 18 m are also installed on rafter beams. Coatings are attached to the columns of the beams with anchor bolts released from the columns and passing through the base sheet welded to the embedded part of the beam. The supporting sheet of the beam is attached to the sheet embedded in the column.

In the longitudinal expansion joints, one of the beams is equipped with a roller support.

The beams are made of concrete of grades 300, 400 and 500, the working reinforcement is made of high-strength wire of class VR-P or rods of steel of class A-IV and A-Shv.

Rice. 55. Reinforced concrete beams: a - lean-to; b - gable; c - with parallel belts

Roof trusses - structures consisting of individual rods connected to each other, forming a frame.

The truss rods located along its upper contour make up the upper belt, and along the lower contour - the lower belt. The vertical rods of the farm are called racks, the inclined ones are called splits. Racks and braces located between the upper and lower chords form a truss lattice, and the points (places) at which the ends of the racks and braces converge are the truss nodes. The area between two adjacent nodes is called a panel.

Depending on the outline of the upper belt, farms are divided into segmented, with parallel belts, etc. (Fig. 56). Reinforced concrete trusses can be solid or composite. Composite farms are made of two semi-farms or several blocks.

Rice. 56. Reinforced concrete prestressed roof trusses: a - segment truss; b - farm with parallel belts

They are used in pitched and flat coatings of one-story industrial buildings with a span of 18 m or more. Roof trusses are installed on reinforced concrete columns or truss trusses. For attaching trusses to columns (rafter trusses), as well as to trusses of roof slabs, lantern frames, ties, they are provided with appropriate steel embedded parts.

Trusses are performed with prestressing of the lower chord and stretched braces (in trusses with parallel chords).

Farms are made of concrete grades 300-500, working fittings. - made of high-strength wire Vr-N and rods made of steel class A-IV
and etc.

Roof trusses and beams are used in the coatings of one-story multi-span industrial buildings along with truss trusses and beams (Fig. 57),

Rafter trusses and beams are used in the middle rows of buildings to support trusses or roof beams in cases where their step is 6 m, and the step of the columns of the middle rows is 12 m.

Rafter trusses (beams) are installed along the building directly on the columns, with which they are fastened by welding embedded parts. All trusses (beams) have the same span of 12 m, except for trusses installed at the ends of the building and at transverse expansion joints, the span of which is 11.5 m (in accordance with the location of the columns). At the ends and in the middle (in the lower node) of the truss trusses (beams), platforms are provided for supporting the truss trusses (beams). The platforms have embedded sheets with anchor bolts welded to them.

Trusses (beams) are made with prestressing of the lower chord from concrete grades 400 and 500. The main (prestressed) reinforcement is made of high-strength wire of class Vr-11 and steel of class A-1U, etc.

Connections. The rigidity of the precast concrete frame in the transverse direction (across the spans) is ensured by the rigidity of the columns themselves and their fixation in the foundations. In the longitudinal direction (along the spans) in buildings with and without overhead cranes at a height of more than 9.6 m, the rigidity of the frame is ensured by the installation of longitudinal vertical steel ties (Fig. 58), which are located in each longitudinal row of columns at the middle of each temperature block. They are made from rolled profiles and welded to special embedded parts of the columns.

Rice. 57. Rafter reinforced concrete prestressed structures: a - beam; b - farm; in-detail of the covering trusses supported on the truss truss; 1 - truss truss; 2 - roof trusses; 3 - coating slabs; 4- embedded parts for attaching trusses; 5 - the same, for fixing plates

Rice. 58. Vertical connections between columns: a - cross; b - portal; 1 - reinforced concrete columns; 2 - crane beams; 3 - beams (or trusses) of the coating; 4 - vertical connections

In addition to the vertical connections between the columns, horizontal and vertical connections are also established between the trusses (beams) of the coating. Horizontal, ontal connections are established in horizontal planes, i.e. in the planes of the upper and lower belts of farms, vertical - in vertical planes between farms.

Frames of multi-storey buildings are frame, bonded and frame-bonded type. For buildings made of prefabricated reinforced concrete elements, frames of a frame-braced system are more often used (Fig. 59).

Rice. 59. A multi-storey building with beam ceilings of a frame-braced system: 1 - self-supporting wall; 2 - crossbar with shelves; 3 - ribbed plates; 4 - column console

Rice. 60. Columns of multi-storey industrial buildings

The main elements of such a frame are columns, crossbars, floor slabs, ties.

Columns (Fig. 60) of the frame of multi-storey industrial buildings usually have a solid rectangular section 400 × 400 or 400 × 600 mm in size, one or two floors high and are of the cantilever type. In terms of the building, the columns have a grid of 6 × 6 or 9 × 6 m.

The columns of the lower floor rest on glass-type foundations. The columns of the upper floors are interconnected by welding embedded steel parts. The ends of the column are equipped with steel heads (welded from angles and strips), to the vertical walls of which the ends of the working reinforcement of the columns are welded. The joint is carried out by welding to the same heads of short butt rods.

In the frames of multi-storey buildings, the joint of columns for ease of installation is usually provided at a height of 0.6 m from the floor level.

The columns are made of concrete grades 200-500, the working arma-TURU is made of A-Sh class steel.

Crossbars (Fig. 61) are used as part of prefabricated reinforced concrete floors in multi-storey buildings. Crossbars are made with shelves for supporting slabs and rectangular cross-section without central locks 6 and 9 m long, 800 mm high and 300 mm wide.

Crossbars with a span of 6 m are made without prestressing. niya, and a span of 9 m - with a prestressing of two or three rods of the lower working reinforcement. For hanging comm. nications in the crossbars there are through holes with a diameter of 50 mm. When mounting the frame, these holes are used to lift the crossbars.

Rice. 61. Rzheli

Rice. 62. Floor slabs

At the ends of the crossbars in the upper part there are recesses in which the outlets of the upper supporting reinforcement of the crossbar are placed, joined with the outlets of the column reinforcement.

Crossbars are installed on the consoles of reinforced concrete columns and connected to the columns by welding reinforcement and embedded parts, followed by embedding. They are made of concrete grades 200-400, reinforcement - from steel of class A-Sh (without prestressing) and A-Shv - for prestressed.

Floor slabs (Fig. 62) are used as part of prefabricated reinforced concrete floors buildings. In multi-storey buildings, two types of floor slabs are used. Plates of the 1st type are made with a width of 1500 and 750 and a length of 5550 and 5050, plates of the 2nd type - with a width of 1500 and a length of 5950 mm. Slabs with a nominal width of 750 mm are laid at the longitudinal walls of the building.

All slabs have a U-shaped section with a height of 400 mm. At the ends of the plates there are blind transverse ribs of the same height (plates of the 1st type) and a height of 150 mm (plates of the 2nd type). In addition, there are three intermediate transverse ribs 200 mm high in the arrival. Plate shelf thickness 50 mm. There are holes in the longitudinal ribs with a diameter of 35 mm (every 1 m) for hanging electrical wiring and other loads weighing up to 300 kg per hole from the ceiling.
Intercolumn slabs (type 2) laid along the longitudinal staking axes, the so-called spacer or bonded slabs, have cutouts in the shelves at the junction with the columns. Plates are made without prestressing or with prestressing of working reinforcement. The longitudinal and transverse ribs of the plates are reinforced with flat welded frames, the shelf with welded mesh. The main reinforcement is rod.

Slabs of the 1st type are laid on the shelves of reinforced concrete crossbars (type 1), slabs of the 2nd type - on top of reinforced concrete crossbars of rectangular cross section (type 2).

Slabs are made from concrete grades 200-300 (slabs of the 1st type) 300-400 (slabs of the 2nd type), and the main working reinforcement is made of steel class A-I, A-Sh and A-Sh in.

Connections. In prefabricated reinforced concrete frames of a frame-braced system of multi-storey buildings, columns and crossbars of floors form a series of transverse frames that provide spatial rigidity of the frame in the transverse direction. The rigidity of the junctions of the crossbars with the columns is achieved by welding the embedded parts of the crossbars and consoles of the columns, as well as welding the outlets of the upper reinforcement of the crossbars with rods passed through the body of the column. The gaps between the columns and the ends of the crossbars are filled with concrete.

To ensure the spatial rigidity of the building frame in the longitudinal direction on all floors in the middle of each temperature block between the columns of the longitudinal rows, vertical steel ties of the cross or portal type are installed, welded to the embedded parts of the columns (see Fig. 58).

In multi-storey buildings, the spatial rigidity of the building as a whole is also ensured by the design of so-called walls (diaphragms) and stiffness cores in them. The stiffening walls are made of prefabricated or monolithic reinforced concrete. As precast concrete, separate Wall panels, which are installed between the columns of the building frame. The panels are fastened to the columns and to each other (along the height of the floors) by electric welding of embedded steel parts in the panels and columns. The number and location of stiffening walls in each building are determined by calculation and indicated in the project.

Spatial stiffness cores, as a rule, are arranged as monolithic reinforced concrete, with a wall thickness of 20-40 cm or more, in a sliding or adjustable formwork. Stair-elevator units, ventilation shafts, garbage chutes and other communications are usually located within the core. Stiffening cores provide (due to beneficial static work) high building rigidity with minimal consumption of concrete and steel compared to flat braced diaphragm systems. In addition, spatial stiffness cores effectively work on the perception of torques that occur under the action of asymmetric horizontal (wind) loads.

expansion joints. In the frames of buildings of considerable length, expansion (temperature) joints are arranged, which dismember the frame and all structures based on it into separate sections - blocks (Fig. 63). There are transverse and longitudinal seams.

Transverse expansion joints are made of double columns and, as a rule, without an insert, i.e., without doubling the transverse center axes. The axis of the expansion joint is combined with the transverse broken axis, and the geometric axes of the columns (as well as those resting on them load-bearing structures ceilings) are displaced from the temperature axis, the leg seam by 500 mm. At the same time, in areas adjacent to the seams at. shortened slabs are changed, and special reinforced concrete elements are used to fill the gap between the paired crossbars.

Rice. 63. Expansion joints in frame buildings; a - scheme of the temperature transverse seam (without insert); b, c - the same, longitudinal seams (with an insert); g - transverse seam in the coating; 1 - row axis; 2 - column axis; 3 - steel table; 4 ~ reinforced concrete insert; 5 - reinforced concrete slab coatings; 6, 7 - compensators; 8 - brick wall; 9 - board; 10 - apron

Longitudinal expansion joints in buildings with a reinforced concrete frame are made of two rows of columns with an insert between the stake axes of 500, 1000 and 1500 mm in size, and in buildings with a steel or mixed frame - from one row of columns.

If there are under-rafter structures in the longitudinal expansion joint in the coating, then for their placement it is necessary to bind columns of 250 mm. Sometimes the temperature seam is combined with the sedimentary seam. In such cases, a temperature-sedimentary seam is also arranged in the foundations of paired columns. The distances between the temperature and temperature-settlement seams for various buildings and structures are given in the relevant design standards.

Building frames. Silos. Silos are used for storage of bulk materials (grain, cement). The frames of the silo are constructed from prefabricated reinforced concrete structures or from monolithic reinforced concrete. However, the construction of monolithic silos has a number of significant drawbacks: the impossibility of applying prestressing reinforcement, heat treatment, etc. The use of monolithic reinforced concrete complicates the work in winter conditions.

Rice. 64. Silo building made of precast concrete (cross section): 1 - large panels; 2 - frame; 3 - plate; 4 - rings; 5 - slag concrete; 6 - columns; 7 - monolithic reinforced concrete slab; 8 - wall blocks; 9 - pilasters in the outer blocks

IN last years they build prefabricated reinforced concrete silos for storing grain and cement, the construction of which largely eliminates the above disadvantages inherent in monolithic silos. In a silo for grain storage, consisting of two blocks of 24 cans with a total capacity of 32 thousand tons, from monolithic reinforced concrete only the foundation slab is performed, the rest of the structures are made of precast concrete (Fig. 64). Silo banks, having a height of about 30 m, consist of reinforced concrete rings 1480 mm high, reinforced with welded meshes; inner diameter of the rings 5.7 m, wall thickness 120 mm, weight 8.1 tons.

Silos for storing cement with a height of about 25 m are mounted from rings 1490 mm high, having an inner diameter of 10 m, walls 200 mm thick and a mass of 24 tons. Trapezoidal grooves are provided for joining the rings at their upper ends, and ridges at the lower ends.

The connection of rings in banks is produced in two ways. The first option is that the rings rest on each other dry on two circular platforms. According to the second option, the joint of the rings is performed with a gap of about 20 mm, which is filled with a solution during installation. Along the circumference of the rings, three steel support tiles are embedded in their grooves and ridges in advance (during manufacture), with which the rings, during installation, rest on each other through centering spacers. The first version of the connection of the rings is much simpler than the second, but does not always provide the exact horizontality of the joints of the rings; with it, local open gaps in the joints and a violation of the verticality of the walls of the cans are possible.

Rice. 65. Fan cooling tower

The connection of the cans to each other along the generatrices is carried out by reinforcing the joint with vertical spatial frames and meshes, which also go into the horizontal joints between the rings. Joint concreting is carried out in metal formwork attached to the outlets of the reinforcement.

Cooling towers. In the USSR, multi-section fan cooling towers from prefabricated reinforced concrete unified elements have been developed and are being built (Fig. 65). The ground frame of such a cooling tower consists of columns with a section of 200 × 200 mm, installed at a distance of 4 m from one another and interconnected by transverse and longitudinal two-branch beams 8 m long with a total section of 500 X 200 mm. Each beam has three sockets for connection with columns. To install sprinkler blocks in the three lower tiers, intermediate beams are laid on the beams of the main frame. The top of the cooling tower consists of reinforced concrete short struts located along the outer perimeter of the cooling tower sections, beams and roof slabs.