The choice of a constructive solution for the external wall insulation system during reconstruction. Structural solutions of buildings Insulating constructive solutions of stone walls include

External walls erected in sliding and reversible formwork can be single-layer, two-layer and three-layer (see Fig. 6.2). When erecting walls in sliding formwork, it is recommended to use monolithic single-layer and three-layer, and in movable formwork - monolithic single-layer, monolithic or prefabricated monolithic two-layer and three-layer.

The compressive strength class of concrete for monolithic concrete walls must be at least B7.5 from heavy concrete and B5 from lightweight concrete. For reinforced concrete B12.5.

The thickness of the outer walls should be set larger based on strength and heat engineering calculation.

Internal monolithic load-bearing walls should be designed as single-layer, their thickness should be determined by the requirements of static reliability, fire resistance and sound insulation.

In monolithic walls, erected in a sliding formwork with the subsequent installation of floors, nests are arranged at the floor level for the possibility of connecting walls and floors. Interfloor floors of monolithic and precast-monolithic buildings can be prefabricated, monolithic and precast-monolithic. Monolithic ceilings are made in movable formwork, prefabricated - from panels manufactured at the factory.

Precast-monolithic floors are usually made of precast reinforced concrete. slabs (shells) with a thickness of at least 4 ... 6 cm and a monolithic layer with a thickness of at least 10 ... 12 cm. Prefabricated shells are mounted on monolithic walls. In the span under the shells, telescopic inventory racks are installed, after which the monolithic layer is concreted.

a) - a single-layer wall without a front protective and finishing layer;

b) - the same with the front protective layer;

c) - two-layer walls with a front protective and finishing layer and a structural and heat-insulating layer;

d) - the same with a heat-insulating layer located on the outside of the wall;

e) - the same with a heat-insulating layer located on the inner side of the wall;

f) - three-layer wall;

1 - bearing layer of concrete;

2 - protective finishing layer;

3 - structural and heat-insulating layer;

4 - bearing layer made of heavy or lightweight concrete;

5 - flexible connections;

6 - heat-insulating layer;

7 - vapor barrier layer;

8 - inner finishing layer;

9 - outer layer;

10 - protective finishing layer.

Figure 6.2 - Structural solutions of external walls

When designing precast-monolithic floors, special attention must be paid to ensuring reliable adhesion between the precast slab and the monolith to ensure their joint work.

Foundations can be designed in the form of flat or ribbed reinforced concrete. slabs, cross belts, box-type or pile-type. The type of foundation is selected on the basis of a technical and economic comparison of options.

Ways to further improve the energy efficiency of buildings

Reducing energy consumption in the construction sector is a complex problem; thermal protection of heated buildings and its control are only part, albeit the most important, general problem. A further decrease in the standardized specific consumption of thermal energy for heating residential and public buildings due to an increase in the level of thermal protection for the next decade is apparently inappropriate. Probably, this decrease will occur due to the introduction of more energy efficient air exchange systems (air exchange control mode on demand, heat recovery of the exhaust air, etc.) and due to the account of the control of the internal microclimate modes, for example, at night. In this regard, it will be necessary to refine the algorithm for calculating energy consumption in public buildings.

Another part of the common, not yet resolved problem is finding the level of effective thermal protection for buildings with indoor air cooling systems during the warm season. In this case, the level of thermal protection in terms of energy saving may be higher than when calculating for heating buildings.

This means that for the northern and central regions of the country, the level of thermal protection can be set on the basis of the conditions for energy saving during heating, and for the southern regions, on the basis of the condition for energy saving during cooling. Apparently, it is advisable to combine the rationing of the consumption of hot water, gas, electricity for lighting and other needs, as well as the establishment of a single rate for the specific energy consumption of a building.

Depending on the type of loads, external walls are divided into:

- load-bearing walls- perceiving loads from the own weight of the walls along the entire height of the building and the wind, as well as from other structural elements of the building (floors, roofs, equipment, etc.);

- self-supporting walls- perceiving loads from the own weight of the walls along the entire height of the building and wind;

- non-bearing(including curtain walls) - which receive loads only from their own weight and wind within one floor and transmit them to the internal walls and floors of a building (a typical example is filler walls in frame housing construction).

Requirements for different types of walls differ significantly. In the first two cases, strength characteristics are very important, since the stability of the entire building largely depends on them. Therefore, the materials used for their construction are subject to special control.

The structural system is an interconnected set of vertical (walls) and horizontal (floors) bearing structures of a building, which together provide its strength, rigidity and stability.

Today, the most used structural systems are frame and wall (frameless) systems. It should be noted that in modern conditions, the functional features of a building and economic prerequisites often lead to the need to combine both structural systems. Therefore, today the device of combined systems is becoming increasingly important.

For frameless structural system use the following wall materials:

Wooden beams and logs;

Ceramic and silicate bricks;

Various blocks (concrete, ceramic, silicate;

Reinforced concrete bearing panels 9panel housing construction).

Until recently, the frameless system was the main one in the mass housing construction of houses of various storeys. But in today's market, when reducing the material consumption of wall structures while ensuring the necessary thermal protection indicators is one of the most pressing issues in construction, the frame system for the construction of buildings is becoming more widespread.

Frame constructions have a high load-bearing capacity, low weight, which makes it possible to erect buildings for various purposes and of various storeys using a wide range of materials as enclosing structures: lighter, less durable, but at the same time providing the basic requirements for thermal protection, sound and noise insulation, fire resistance ... These can be piece materials or panels (metal like sandwich or reinforced concrete). Exterior walls in frame buildings are not load-bearing. Therefore, the strength characteristics of the wall filling are not as important as in frameless buildings.

The outer walls of multi-storey frame buildings are attached to the load-bearing elements of the frame by means of embedded parts or rest on the edges of the floor disks. Fastening can be carried out by means of special brackets fixed to the frame.

From the point of view of the architectural planning and purpose of the building, the most promising is the option of a frame with a free layout - floors on load-bearing columns. Buildings of this type make it possible to abandon the typical layout of apartments, while in buildings with transverse or longitudinal load-bearing walls, this is almost impossible to do.

Frame houses have also proven themselves in seismically hazardous areas.
For the construction of the frame, metal, wood, reinforced concrete are used, and the reinforced concrete frame can be either monolithic or prefabricated. Today, the most commonly used rigid monolithic frame filled with effective wall materials.

Light frame metal structures are increasingly used. The construction of the building is carried out from separate structural elements at the construction site; or from modules installed on site.

This technology has several main advantages. Firstly, it is fast construction of the structure (short construction period). Secondly, the possibility of forming large spans. And finally, the lightness of the structure, which reduces the load on the foundation. This allows, in particular, to arrange attic floors without strengthening the foundation.

A special place among metal frame systems is occupied by systems made of thermoelements (steel profiles with perforated walls interrupting cold bridges).

Along with reinforced concrete and metal frames, timber frame houses are well known for a long time, in which the supporting element is a wooden frame made of solid or glued wood. Compared to chopped wood frame structures, they are more economical (less wood consumption) and a minimum susceptibility to shrinkage.

Another method of modern construction of wall structures is somewhat apart - the technology with the use of fixed formwork. The specificity of the systems under consideration lies in the fact that the elements of the permanent formwork themselves are not load-bearing. structural elements. During the construction of the structure, by installing reinforcement and pouring concrete, a rigid reinforced concrete frame is created that meets the requirements for strength and stability.

Exterior wall structures are classified according to the following criteria:

The static function of the wall, determined by its role in the structural system of the building;

Material and construction technologies determined by the building's building system;

Constructive solutions - in the form of a single-layer or layered enclosing structure.

According to the static function, they are distinguished (Figure 4.4) load-bearing walls (4.3), self-supporting walls(4.4) and curtain walls (4.5).

Figure 4.4. Classification of external walls by bearing capacity: a - bearing; b - self-supporting; c - non-bearing

The non-bearing walls are supported by the floor on the adjacent internal structures of the building (floors, walls, frame).

Bearing and self-supporting walls perceive along with vertical and horizontal loads, being the vertical stiffeners of structures. In buildings with non-bearing external walls, the functions of vertical stiffeners are performed by the frame, internal walls, diaphragms or stiffeners.

Bearing and non-bearing external walls can be used in buildings of any number of storeys. The height of self-supporting walls is limited in order to prevent operationally unfavorable mutual displacements of self-supporting and internal supporting structures, accompanied by local damage to the decoration of the premises and the appearance of cracks. In panel houses, for example, it is permissible to use self-supporting walls with a building height of no more than 4 floors. The stability of self-supporting walls is ensured by flexible connections with internal structures.

Load-bearing external walls are used in buildings of various heights. The maximum number of storeys of a load-bearing wall depends on the bearing capacity and deformability of its material, design, the nature of the relationship with internal structures, as well as on economic considerations. So, for example, the use of lightweight concrete panel walls is advisable in houses with a height of up to 9 - 12 floors, load-bearing brick outer walls - in mid-rise buildings, and steel lattice shell walls - in 70 - 100-storey buildings.

By material, there are four main types of wall structures: concrete, stone, non-concrete materials and wood. In accordance with the building system, each type of wall contains several types of structures: concrete walls - made of monolithic concrete, large blocks or panels; stone walls - brick or small blocks, walls of large stone blocks and panels; wooden walls - chopped, frame-panel, panel and panel.

Exterior walls can be of single or layered construction. Single-layer walls are built from panels, concrete or stone blocks, monolithic concrete, stone, brick, wooden logs or beams. In layered walls, different functions are assigned to different materials. Strength functions are provided by concrete, stone, wood; durability functions - concrete, stone, wood or sheet material (aluminum alloys, enameled steel, asbestos cement, etc.); thermal insulation functions - effective insulation (mineral wool boards, fiberboard, expanded polystyrene, etc.); vapor barrier functions - roll materials (cushioning roofing material, foil, etc.), dense concrete or mastics; decorative functions - various facing materials. An air gap can be included in the layers of such a building envelope. Closed - to increase its resistance to heat transfer, ventilated - to protect the room from radiation overheating or to reduce deformations of the outer facing layer of the wall.

Study and analyze the above material and answer the proposed question.

The vertical structural elements of the building that separate the premises from the external environment and divide the building into separate premises are called walls. They perform enclosing and bearing (or only the first) functions. They are classified according to various criteria.

By location - external and internal.

Exterior walls- the most complex building structure. They are exposed to many and varied forceful and non-forceful influences. Walls perceive their own mass, permanent and temporary loads from ceilings and roofs, wind effects, uneven deformations of the base, seismic forces, etc. from the inside - to the effect of heat flow, water vapor flow, noise.

Performing the functions of an external enclosing structure and a composite element of facades, and often a supporting structure, the external wall must meet the requirements of strength, durability and fire resistance, corresponding to the class of capital of the building, protect the premises from adverse external influences, provide the necessary temperature and humidity regime of the enclosed premises, have decorative qualities.

The structure of the outer wall must meet the economic requirements of minimum material consumption and cost, since the outer walls are the most expensive structure (20-25% of the cost of building structures).

In the outer walls, there are usually window openings for lighting the premises and doorways - entrance and for access to balconies and loggias. The complex of wall structures includes filling the openings of windows, entrance and balcony doors, structures of open spaces.

These elements and their connections to the wall must meet the requirements listed above. Since the static functions of walls and their insulating properties are achieved in interaction with internal supporting structures, the development of external wall structures includes the solution of mates and joints with ceilings, internal walls or a frame.

External walls, and with them the rest of the building structures, if necessary and depending on the climatic and engineering-geological conditions of construction, as well as taking into account the peculiarities of space-planning solutions, are cut by vertical expansion joints of various types: temperature, sedimentary, anti-seismic, etc. ...

Internal walls are divided into:

Interroom;

Intra-apartment (walls and partitions);

Walls with ventilation ducts (near the kitchen, bathrooms, etc.).

Depending on the adopted structural system and building scheme, the external and internal walls of the building are subdivided into load-bearing, self-supporting and non-bearing (Fig. 84).

Fig. 84. Wall constructions:

a - carriers; b - self-supporting; c - mounted

Partitions- these are vertical, as a rule, non-bearing fences, dividing the internal volume of the building into adjacent rooms.

They are classified according to the following criteria:

By location - interroom, interroom, for kitchens and plumbing units;

By function - deaf, with openings, incomplete, that is, not reaching

By design - solid, frame, sheathed outside with sheet material;

By the method of installation - stationary and transformable.

Partitions must meet the requirements of strength, stability, fire resistance, sound insulation, etc.

Carriers the walls, in addition to the vertical load from their own mass, perceive and transfer to the foundations loads from adjacent structures: floors, partitions, roofs, etc.

Self-supporting the walls take the vertical load only from their own weight (including the load from balconies, bay windows, parapets and other wall elements) and transfer it to the foundations directly or through basement panels, randbeams, grillages or other structures.

Non-bearing walls by floor (or through several floors) are supported on adjacent internal structures of the building (floors, walls, frame).

Bearing and self-supporting walls perceive along with vertical and horizontal loads, being the vertical stiffeners of structures.

In buildings with non-bearing external walls, the functions of vertical stiffeners are performed by the frame, internal walls, diaphragms or stiffeners.

Bearing and non-bearing external walls can be used in buildings of any number of storeys. The height of self-supporting walls is limited in order to prevent operationally unfavorable mutual displacements of self-supporting and internal supporting structures, accompanied by local damage to the decoration of the premises and the appearance of cracks. In panel houses, for example, it is permissible to use self-supporting walls with a building height of no more than 4 floors. The stability of self-supporting walls is ensured by flexible connections with internal structures.

Load-bearing external walls are used in buildings of various heights.

The maximum number of storeys of a load-bearing wall depends on the bearing capacity and deformability of its material, design, the nature of the relationship with internal structures, as well as on economic considerations. So, for example, the use of lightweight concrete panel walls is advisable in houses up to 9-12 floors high, bearing brick outer walls - in middle-rise buildings (4-5 floors), and steel lattice shell walls - in 70-100-storey buildings.

By design - small-element (brick, etc.) and large-element(from large panels, blocks, etc.)

In terms of mass and degree of thermal inertia, the external walls of buildings are divided into four groups - massive (more than 750 kg / m 2), medium massive (401-750 kg / m 2), light (150-400 kg / m 2), especially light (150-400 kg / m 2).

By material, the main types of wall structures are distinguished: concrete, stone from non-concrete materials and wood... In accordance with the building system, each type of wall contains several types of structures: concrete walls - from monolithic concrete,

large blocks or panels; stone walls - hand-made, walls made of stone blocks and panels; walls made of non-concrete materials - half-timbered and panel frame and

frameless; wooden walls - frame-sheathing, frame-panel, shield and panel walls, chopped from logs or beams. Concrete and stone walls are used in buildings of various storeys and for various static functions in accordance with their role in the building's structural system. Walls made of non-concrete materials are used in buildings of various storeys only as a non-bearing structure.

Exterior walls can be single-layer or sandwich construction.

Single layer e walls are erected from panels, concrete or stone blocks, monolithic concrete, stone, brick, wooden logs or beams. V layered walls, the performance of different functions is assigned to different materials. Strength functions are provided by concrete, stone, wood: durability functions - concrete, stone, wood or sheet material (aluminum alloys, clad steel, asbestos cement, etc.); thermal insulation functions - effective insulation (mineral wool boards, fiberboard, expanded polystyrene, etc.); vapor barrier functions - roll materials (cushioning roofing material, foil, etc.), dense concrete or mastics; decorative functions - various facing materials. An air gap can be included in the layers of such a building envelope. Closed- to increase its resistance to heat transfer, ventilated- to protect the premises from radiation overheating or to reduce deformations of the outer facing layer of the wall.

Single and multi-layer wall structures can be made pre-assembled or using traditional techniques.

Wall structures must meet the requirements of capital, strength and stability. The heat-shielding and sound-insulating capacity of the walls is established on the basis of heat-engineering and sound-proof calculations.

The thickness of the outer walls is selected according to the largest of the values ​​obtained as a result of static and heat engineering calculations, and is assigned in accordance with the structural and heat engineering features of the enclosing structure.

Rice. 85. Uniform brickwork:

a - six-row dressing system; b - chain (two-row dressing system).

Fig. 86. Well masonry of brick walls:

a - with horizontal diaphragms made of cement-sand mortar; b - the same, from staggered butt bricks; in - the same, located in the same plane; d - perspective view of the masonry.

Rice. 87. Exterior wall panels:

a - single layer; b - two-layer; c - three-layer; 1 - structural and heat-insulating concrete; 2 - protective finishing layer; 3 - structural concrete; 4 - effective insulation.

The foundation is the underground part of the building, which perceives all loads, both permanent and temporary, arising in the above-ground parts, and transfers these loads to the foundation. Foundations must meet the requirements of strength, stability, durability and economy. In this project, the foundation was selected in accordance with the requirements of industrialization, achieved by using prefabricated prefabricated or landfill blocks with their maximum enlargement, as far as the hoisting and transport mechanisms available at the construction site allow.

In this building, a prefabricated reinforced concrete strip foundation is designed for load-bearing and self-supporting walls. The strip foundation is a continuous wall evenly loaded with overlying load-bearing and self-supporting walls and columns. Prefabricated strip foundations for walls are constructed from foundation cushion blocks and from foundation wall blocks. Cushion blocks are laid on a layer of compacted sand 100 mm thick.

Slabs-cushions for external walls are 1400 mm wide. Cushion slabs for internal walls are 1000 mm wide. The cushion slabs can be laid with breaks. At the junctions of the longitudinal and transverse walls of the slab, the cushions are placed end-to-end and the junctions between them are sealed with a concrete mixture. On top of the laid cushion slabs, horizontal waterproofing is arranged and on top of it a cement-sand screed 30 mm thick, into which a reinforcing mesh is laid, which leads to a more even distribution of the load from the overlying blocks and structures.

Then concrete foundation blocks are laid with bandaging of seams in five rows, on top of which a horizontal waterproofing layer of two layers of roofing material on mastic is arranged. The purpose of the waterproofing layer is to exclude the migration of capillary soil and atmospheric moisture up the wall. The width of the foundation blocks for the outer walls is 600 mm. The width of the foundation blocks for internal walls is 400 mm.

The depth of the foundation or the distance from the planning mark of the earth to the base of the foundation is taken depending on the geological and hydrogeological conditions of the construction site, and on the climatic conditions of the area. The depth of the foundation of this building is 2.18 m, which exceeds the depth of soil freezing, which in this area is 1.9 m.

Exterior walls

In the construction of low-rise buildings, load-bearing skeletons are used that correspond to the types and properties of construction materials and the technology for the construction of such buildings. In this project, a load-bearing frame with transverse and longitudinal load-bearing walls is used. The stability of the walls, both bearing and braced, is ensured by a rigid connection of the longitudinal and transverse walls at their intersection and by the connection of the walls with ceilings.

The walls of the building are designed for fencing and protection from environmental influences and transfer loads from the structures located above - floors and roofs to the foundation.

Clay ordinary corpulent brick is used as a material for the walls of the building. The walls are laid out of bricks with filling the gap between them with mortar. The mortar is used in cement. The masonry of the walls is carried out with the obligatory observance of the multi-row dressing of the seams. With a multi-row masonry system, dressing is carried out through five rows. Multi-row masonry is more economical than two-row masonry, since it requires less manual labor.

The design adopted a lightweight well masonry with filling of voids with mineral wool slabs. The walls between the windows are reinforced with mesh reinforcement through 3 rows of masonry. The walls are erected by laying lightweight insulating materials inside the stone wall - between two rows of solid walls. The thickness of the outer walls is determined on the basis of a heat engineering calculation. The thickness of the outer walls is 720 mm, the binding is 120 mm. This thickness is necessary to ensure resistance to wind and shock loads, as well as to increase the heat and sound insulation capacity of the walls.

Openings for windows and doors are provided with quarters. The quarters are installed in the side and upper lintels of the outer walls to ensure a tight, windproof abutment of the filling elements - window and door frames. Doorways in the inner walls are made without quarters. A quarter is made by means of a brick protrusion at the outer surface of the wall by 75 mm. The openings are covered with lintels that take the load of the overlying masonry. Lintels are reinforced concrete bars or beams.

To protect the outer walls from moisture and to increase durability, a plinth is arranged. The plinth is made of durable waterproof durable materials. The height of the basement, due to the presence of a basement floor, is assumed to be 0.85 m.