Purpose of expansion joints, types of expansion joints: for bridges, between buildings, in industrial buildings, between walls, subheadings. Alternative energy and energy saving Insulation of expansion joints between buildings

Since in recent times prices for various building materials are growing rapidly, you need to think about how to create effective and high-quality buildings so that after construction you do not have to correct mistakes. In order to eliminate possible errors and risks, it is necessary to organize expansion joints in concrete during the construction of any buildings. These designs minimize various deformations.

Various concrete structures are no exception. These can be floors, blind areas and many other structures. If the choice of technology for creating the floor is wrong, then as a result it will be covered with cracks, and topcoat deformed.

The condition of the foundation tape depends on the blind area. If it cracks, then this can cause moisture to penetrate into the base and ultimately result in very serious consequences.

How do they look?

By appearance they are cuts in the concrete. Thanks to these cuts, cracking of the base will not occur with sharp and smooth temperature changes. This can be explained by the fact that the base can expand, there is enough space for this.

So, there is a large number of similar protective building structures. The SNIP classification contains not only temperature seams, but also many other types of seams.

Variety of concrete joints

So, among the seams are distinguished:

• Shrinkage;
• Sedimentary and temperature;
• Anti-seismic.

Heat shrinkage joints are temporary lines. They are created mainly in monolithic structures directly when pouring concrete mixtures. When the mixture begins to dry, it will shrink. This can form cracks. So, the solution will contract, and the pressure will act on the line of the void, which will expand. Then, when everything is dry, the line will be destroyed.

As for the second group, these grooves are designed to keep the building from precipitation and temperature changes. A sedimentary seam can be found on any elements of the building, as well as at the base. The temperature cut can be found everywhere, on any element, but not on the foundation. For example, in most buildings, expansion joints can be found in the walls.

Anti-seismic protection - these are special lines that divide the building into blocks. Where these lines pass, double walls or special racks are created. This makes the building more stable.

Protects against sudden changes in temperature and deformation

According to their design features, the expansion joint is a special groove, line. He divides the entire building into blocks. The size of such blocks and the directions in which the notch line divides the building is determined by the project, as well as by special calculations.

In order to seal these grooves, and also to minimize heat loss, these grooves are filled with heat insulators. Often used various materials based on rubber. So, the elasticity of the building increases significantly, and thermal expansion will not destructively affect other materials.

Often, this cut is made from the roof to the base. The very foundation of the building is not divided, since the foundation is lower than the depth at which the soil freezes. The base will not be affected by low temperatures. The spacing of the expansion joint depends on the materials used, as well as on the point on the map where the object is located.

Most buildings and structures can use numbers from tables. The distance between the expansion joints will be 150 m for buildings that are prefabricated and heated, or 90 m for monolithic heated structures.

Where is there no heating?

In this case, these figures are reduced by 20%. To prevent effort, in the event of uneven settlement, settlement seams can be arranged. Also, this protection can act as a thermal one. The sedimentary section must be created to the bottom. Temperature - up to the top of the foundation. The width of the expansion joint should be 3 cm.

Protection in homes where people live

The expansion joint in a residential building has ancient history... They began to use these technologies during the construction of the first Egyptian Pyramid. Then it began to be used for any stone structures. With the help of this trick, people have learned to save their homes from temperature surges and other natural disasters.

The operation of residential buildings often leads to different types destruction of the base and foundation. Among the multitude possible reasons you can distinguish the movement of the ground under the house. This is a signal of a violation of waterproofing. Subsequently, the house will collapse sooner or later.

How it's done

Every home has a hammer drill. So, with the help of a drill, you need to make a horizontal cut in the wall. Then it is necessary to seal the seam with roofing felts, tow, and at the end a special lock should be made from water, sand, clay and straw. It is necessary to seal the expansion joint well with this composition.

And if the house is made of bricks

Here, such means of protection should be provided at the design stage. In order to equip the cut, use a tongue in brickwork, which will be lined with two layers of roofing. Then everything is pulled together with a layer of tow and again you need to cover everything with a lock based on water and clay.

1. The sheet pile is created during the construction phase of the building. However, if it is not and is not provided for, and it is very necessary to make such a protective agent, then everything can be done with a puncher, but you need to work very carefully. What is tongue and groove? This is a technological notch. The dimensions of such a recess are 2 bricks high and 0.5 deep.
2. At this stage, it is necessary to overlay the future expansion joint in the brickwork with the same tar paper and clog it with the same tow. Thanks to its unique properties these materials do not react in any way to temperature jumps, and the masonry, in turn, will not react to them either.
3. Now it's time to close this groove. Most people use concrete or cement mortar... However, a clay-based putty is much better suited for this purpose. Efficiency is due to the fact that clay is an excellent heat insulator and waterproofing agent. Also, clay also has a decorative function.

Protecting the blind area

So, in order to perform expansion joints in the blind area, you must:

• Dig a trench along the petymeter of the structure. Its depth should be 15 cm. The width of the trench should be larger than the roofing canopy;
• Fill a crushed stone pillow to the bottom of the trench, and lay on top with roofing felt around the entire perimeter;
• Carry out the installation of the frame based on the reinforcement.

Before moving on to concrete works on the blind area, we will perform a protective seam. It should be done on the line where the walls and blind area join. To organize the groove, it is enough to install boards of small thickness between the blind area and the wall. Also, these grooves are needed across. This is done in the same way. You need to maintain a distance of 1.5 m.

After pouring, the concrete mixture will go where it is needed, but grooves will remain where the boards are installed. After the mortar has hardened sufficiently, the wood can be pulled out. The slots can be blown out with sealant or other means. The most important thing is that the cuts are not empty, otherwise the protection will be zero.

What about the concrete floor?

Expansion joints in floors can be made even after the mixture has hardened sufficiently. Of course, it is better to take care of them even before the pouring process.

To perform such protection in the floor, you need:

• Define lines for cutting concrete. The distance can be easily and simply calculated. So, 25 must be multiplied by the size of the floor thickness;
• Cut grooves with a power tool. The depth will be 1/3 of the thickness. Optimal dimensions in width - a couple of centimeters;
• Remove all dust from the grooves and prime;
• When dry, the slots should be filled with any material intended for this purpose.

These actions will not cause difficulties for anyone. What happened? If the floor deforms, then these processes will follow the lines of the seams. The screed may crack a little here, but fine flooring will remain perfectly intact.

It turns out that such events and simple technological operations, both on the street and in a house or any other building, help protect the building. If, once, using inexpensive materials and a perforator, you create an expansion joint in a slab, floor and anywhere, you can significantly save in the future and extend the service life of the building.

CENTRAL ORDER OF LABOR RED BANNER SCIENTIFIC RESEARCH AND DESIGN INSTITUTE OF TYPICAL AND EXPERIMENTAL DESIGN OF HOUSING (TSNIIEP HOUSING) STATE ARCHITECTURE

MANUAL

for the design of residential buildings

Part 1

Residential building structures

(to SNiP 2.08.01-85)

Contains recommendations on the selection and layout of the structural system and the design of residential buildings. The features of designing structures for large-panel, volume-block, monolithic and prefabricated-monolithic residential buildings are considered. Practical methods for calculating load-bearing structures are presented, as well as examples of calculation.

The manual is intended for residential building design engineers.

FOREWORD

The main direction of industrialization of housing construction in our country is the development of frameless large-panel housing construction, which accounts for more than half of the total volume of construction of residential buildings. Large-panel buildings are made of relatively easy-to-manufacture flat large-sized elements. Along with planar elements in large panel buildings also used are volumetric elements saturated with engineering equipment (sanitary cabins, tubing of elevator shafts, etc.).

The construction of large-panel buildings allows, in comparison with brick buildings, to reduce the cost by an average of 10%, the total labor costs - by 25 - 30%, the duration of construction - by 1.5 - 2 times. Houses made of three-dimensional blocks have technical and economic indicators close to large-panel buildings. An important advantage of a three-dimensional block house is a sharp reduction in labor costs for construction site(2 - 2.5 times compared with large-panel housing construction), achieved due to a corresponding increase in the labor intensity of work at the plant.

In the last decade, housing construction has developed in the USSR from monolithic concrete... The construction of monolithic and prefabricated-monolithic residential buildings is advisable in the absence or insufficient capacity of the prefabricated housing base, in seismic regions, as well as if it is necessary to construct buildings of increased number of storeys. The erection of monolithic and prefabricated-monolithic buildings requires significantly lower (in comparison with large-panel housing construction) capital costs, reduces the consumption of reinforcing steel by 10-15%, but at the same time leads to an increase of 15-20% in construction costs.

The use in modern residential buildings made of monolithic concrete of inventory formwork, prefabricated reinforcement elements (nets, frames), mechanized methods of transporting and placing concrete makes it possible to characterize monolithic housing construction as industrial.

In this Guide to the design of residential buildings, the main attention is paid to the most massive and economical building systems of frameless residential buildings - large-panel, volume-block, monolithic and precast-monolithic. For other constructive types of residential buildings (frame, large-block, brick, wooden), only minimal information is provided and links to regulatory and methodological documents are given, where the design of structures of such systems is considered.

The manual contains provisions for the design of structures of residential buildings erected in non-seismic regions, in terms of the selection and layout of structural systems, design of structures and their calculation for force effects.

The manual was developed by TsNIIEP of the housing of the State Committee for Architecture and Construction (Candidates of Technical Sciences V.I. Lishak - head of the work, V.G. Berdichevsky, E.L. V. Kazakov, E. I. Kireeva, A. N. Mazalov, N. A. Nikolaev, K. V. Petrova, N. S. Strongin, M. G. Taratuta, M. A. Khromov, N. N Tsaplev, V. G. Tsimbler, G. M. Shcherbo, O. Yu. Yakub, engineers D. K. Baulin, S. B. Vilensky, V. I. Kurchikov, Yu. N. Mikhailik, I. A. Romanova) and TsNIIPImonolit (Candidates of Technical Sciences Yu. V. Glina, L. D. Martynova, M. E. Sokolov, engineers V. D. Agranovsky, S. A. Mylnikov, A. G. Selivanova, Ya. I. Tsirik) with the participation of MNIITEP GlavAPU of the Moscow City Executive Committee (candidates of technical sciences V.S.Korovkin, Yu.M. Strugatsky, V.I. Yagust, engineers G.F.Sedlovets, G.I. Shapiro, Yu.A. Eisman) LenNNIproject of the GlavAPU of the Leningrad City Executive Committee (Candidate of Technical Sciences V.O. Koltynyuk, engineer A.D. Nelipa), TsNIISK im. V.A.Kucherenko of the USSR State Construction Committee (candidates of technical sciences A.V. Granovsky, A.A.Emelyanov, V.A.Kameiko, P.G.Labozin, N.I. A. M. Dotlibov, M. M. Chernov), NIIZhB, NIIOSP them. NM Gersevanov of the USSR State Construction Committee, the Mosstroy Research Institute of the Glavmosstroy of the Moscow City Executive Committee and the LenZNIIEP of the State Committee for Architecture.

Please send your comments and comments to the address: 127434, Moscow, Dmitrovskoe shosse, 9, bldg. B, TsNIIEP dwelling, department of structural systems of residential buildings.

1. GENERAL PROVISIONS

1.1. The Manual provides data on the design of structures for apartment buildings and dormitories with a height of up to twenty-five floors, inclusive, erected in non-seismic regions on foundations composed of rocky, coarse-grained, sandy and clayey soils (normal soil conditions). The Manual does not consider the design features of buildings for seismic regions and buildings erected on subsiding, frozen, swelling, water-saturated peat soils, silts, undermined areas and in other difficult soil conditions.

When designing structures, along with the requirements of SNiP 2.08.01-85, the provisions of other regulatory documents, as well as the requirements state standards on a structure of the corresponding type.

1.2. It is recommended to choose the constructive solution of the building on the basis of a technical and economic comparison of options, taking into account the existing production and raw material base and transport network in the construction areas, planned construction sites, local climatic and engineering-geological conditions, architectural and urban planning requirements.

1.3. Residential buildings are recommended to be designed with load-bearing structures made of concrete and reinforced concrete (concrete buildings) or stone materials in combination with reinforced concrete structures (stone buildings). Residential buildings one to two storeys high can also be designed with timber-based structures (wooden buildings).

1.4. Concrete buildings are subdivided into prefabricated, monolithic and precast monolithic.

Prefabricated buildings are made of prefabricated products of factory or polygon production, which are installed in the design position without changing their shape and size.

In monolithic buildings, the main structures are made of monolithic concrete and reinforced concrete.

Prefabricated monolithic buildings are erected using prefabricated products and monolithic structures.

In conditions of mass construction, it is recommended to predominantly use prefabricated buildings, which make it possible to mechanize the process of erection of structures to the greatest extent, reduce the construction time and labor costs at the construction site. Monolithic and prefabricated-monolithic buildings are recommended mainly for use in areas with warm and hot climates, in areas where there is no industrial base for prefabricated housing construction or their capacity is insufficient, as well as, if necessary, in any areas of construction of high-rise buildings. With a feasibility study, it is possible to carry out individual structural elements from monolithic reinforced concrete in prefabricated buildings, including stiffening cores, structures of lower non-residential floors, foundations.

Rice. 1. Large-sized prefabricated elements of residential buildings

a¾ wall panels; b¾ floor slabs; v¾ roofing boards; G¾ volumetric blocks

Panel is called a plane prefabricated element used for the construction of walls and partitions. A panel that is one floor high and at least as long as the size of the room it encloses or divides is called a large panel, panels of other sizes are called small panels.

Precast plate is called a prefabricated planar element used in the construction of floors, roofs and foundations.

Block is called a self-stable prefabricated element during installation, predominantly of a prismatic shape, used for the construction of external and internal walls, foundations, ventilation and garbage chutes, placement of electrical or sanitary equipment. Small blocks are usually installed manually; large blocks - using mounting mechanisms. Blocks can be solid or hollow.

Large blocks of concrete buildings are made of heavy, lightweight or aerated concrete. For buildings with a height of one or two floors with an expected service life of no more than 25 years, gypsum concrete blocks can be used.

Volumetric block is called a pre-fabricated part of the volume of a building, fenced off from all or some of the sides.

Volumetric blocks can be designed as bearing, self-supporting and non-bearing.

A bulk block is called a load-bearing block, on which the volume blocks located above it, floor slabs or other supporting structures of the building are supported.

Self-supporting is a volumetric block in which the floor slab rests on the load-bearing walls or other vertical load-bearing structures of the building (frame, staircase and elevator shaft) and participates together with them in ensuring the strength, rigidity and stability of the building.

A non-bearing block is a volumetric block that is installed on the floor, transfers loads to it and does not participate in ensuring the strength, rigidity and stability of the building (for example, a sanitary cabin installed on the floor).

Prefabricated buildings with large panel walls and precast slab floors are called large-panel. Along with flat prefabricated elements in a large-panel building, non-bearing and self-supporting volumetric blocks can be used.

A prefabricated building with large block walls is called large-block.

A prefabricated building made of load-bearing volumetric blocks and plane prefabricated elements is called panel-block.

A prefabricated building made entirely of volumetric blocks is called volumetric block.

Monolithic and precast-monolithic buildings according to the method of their construction, it is recommended to use the following types:

with monolithic external and internal walls, erected in sliding formwork (Fig. 2, a) and monolithic ceilings erected in small-panel formwork using the "bottom-up" method (Fig. 2, b), or in large-panel slab formwork using the "top-down" method (Fig. 2, v);

with monolithic internal and end external walls, monolithic ceilings, erected in volumetric-movable formwork, removed to the facade (Fig. 2, G), or in large-panel formwork of walls and floors (Fig. 2, d). In this case, external walls are made monolithic in large-panel and small-panel formwork after the construction of internal walls and ceilings (Fig. 2, e) or from prefabricated panels, large and small blocks of brickwork;

with monolithic or prefabricated monolithic external walls and monolithic internal walls erected in movable formwork, retrieved upwards (large-panel or large-panel in combination with block formwork) (Fig. 2, f, s). Overlappings in this case are made prefabricated or precast-monolithic with the use of prefabricated slabs - shells that play the role of permanent formwork;

with monolithic external and internal walls, erected in a volumetric mobile formwork (Fig. 2, and) by the method of tiered concreting, and prefabricated or monolithic ceilings;

with monolithic internal walls erected in large-panel wall formwork. In this case, the ceilings are made of prefabricated or precast-monolithic slabs, the outer walls are made of prefabricated panels, large and small blocks, brickwork;

with monolithic stiffening cores, erected in a movable or sliding formwork, prefabricated panels of walls and floors;

with monolithic stiffening cores, prefabricated frame columns, prefabricated exterior wall panels and slabs erected by the lifting method.

Rice. 2. Types of monolithic frameless buildings erected in sliding ( a— v), volumetric-adjustable and large-panel ( G— e), block and large-panel ( f - and) formwork (arrows show the direction of movement of the formwork)

1 — sliding formwork; 2 - small-panel slab formwork; 3 — large-panel slab formwork; 4 - volumetric movable wall formwork; 5 — large-panel wall formwork; 6 - small-panel wall formwork; 7 - block formwork

Sliding formwork called a formwork, consisting of shields fixed on jack frames, a working floor, jacks, pumping stations and other elements, and designed for the construction of vertical walls of buildings. The entire system of sliding formwork elements as the walls are concreted is lifted up by jacks at a constant speed.

Small-panel formwork called a formwork, consisting of sets of boards with an area of ​​about 1 m 2 and other small elements weighing no more than 50 kg. It is allowed to assemble panels into enlarged elements, panels or spatial blocks with a minimum number of additional elements.

Large-panel formwork called a formwork, consisting of large-sized panels, connection and fastening elements. Formwork panels accept all technological loads without installing additional bearing and supporting elements and are completed with scaffolds, struts, adjusting and installation systems.

called the formwork, which is a system of vertical and horizontal shields, hinged-united into a U-shaped section, which in turn is formed by connecting two L-shaped half-sections and, if necessary, inserting a floor shield.

Volumetric mobile formwork called the formwork, which is a system of outer panels and a folding core, moving in layers along the vertical in four racks.

Block formwork called the formwork, consisting of a system of vertical panels and corner pieces, hingedly united by special elements into spatial block-forms.

1.5. Stone buildings can have walls of masonry or prefabricated elements (blocks or panels).

Masonry is made of bricks, hollow ceramic and concrete stones (from natural or artificial materials), as well as lightweight brickwork with slab insulation, backfill from porous fillers or foamable in the cavity of the masonry polymer compositions.

Large blocks of stone buildings are made of bricks, ceramic blocks and natural stone(sawn or clean teska).

Panels of stone buildings are made of vibrobrick or ceramic blocks. Exterior wall panels can have a layer of insulated slabs.

When designing the walls of stone buildings, one should be guided by the provisions of SNiP II-22-81 and the corresponding manuals.

1.6. Wooden buildings are subdivided into panel, frame and block.

Wooden panel buildings are made of panels made using solid and (or) glued wood, plywood and (or) profile products from it, chipboard, fibreboard and others sheet materials based on wood. The structures of wooden panel buildings should be designed in accordance with SNiP II-25-80 and "Guidelines for the design of structures for wooden panel residential buildings" (TsNIIEPgrazhdanselstroy, M., Stroyizdat, 1984).

Wooden frame buildings are made of timber frame, which is collected at the construction site and sheathed with sheet material, between which heat and sound insulation from slabs or backfills is arranged.

In log buildings, the walls are made of solid wood in the form of beams or logs. Log buildings are used mainly in rural manor construction in forestry areas.

1.7. When designing structures for residential buildings, it is recommended:

choose the best in technical and economic terms, design solutions;

comply with the requirements Technical regulations economical use of basic building materials;

comply with the established maximum consumption rates for reinforcing steel and cement;

provide for the use of local building materials and concrete based on gypsum binders;

apply, as a rule, unified standard or standard structures and formwork, allowing the building to be erected by industrial methods;

to reduce the range of prefabricated elements and formwork through the use of enlarged modular grids (with a module of at least 3M); to unify the parameters of structural and planning cells, reinforcement schemes, the location of embedded parts, holes, etc .;

provide for the possibility of interchangeable use of external enclosing structures, taking into account the local climatic, material and production conditions of construction and the requirements for the architectural solution of the building;

provide for the manufacturability of the manufacture and installation of structures;

use structures that provide the lowest total labor intensity of their manufacture, transportation and installation;

apply technical solutions, requiring the least expenditure of energy resources for the manufacture of structures and heating the building during its operation.

1.8. In order to reduce the material consumption of the structure, it is recommended:

accept the structural systems of the building allowing full use of bearing capacity structures, if possible, reduce the class of concrete and change the reinforcement of structures along the height of the building;

take into account the joint spatial work of structural elements in the building system, providing it structurally by connecting prefabricated elements with ties, combining wall sections separated by openings with jumpers, etc.;

reduce the load on structures through the use of lightweight concrete, lightweight structures made of sheet materials for non load-bearing walls and partitions, layered and hollow-core bearing concrete and reinforced concrete structures;

the compressive strength of load-bearing walls is predominantly ensured due to the resistance of concrete (without the calculated vertical reinforcement);

to prevent the formation of cracks in the structure during their manufacture and erection, mainly due to technological measures (selection of appropriate concrete compositions, heat treatment modes, molding equipment, etc.), without using additional structural reinforcement for technological reasons;

to accept such schemes of transportation, installation and removal from the form of prefabricated elements, which, as a rule, do not require their additional reinforcement;

provide for the installation of prefabricated elements mainly with the help of traverses, providing the vertical direction of the lifting slings;

use lifting eyes as parts for connecting prefabricated elements to each other.

1.9. In order to reduce the total labor costs for the manufacture and erection of structures in the design of prefabricated buildings, it is recommended:

enlarge prefabricated elements within the carrying capacity of mounting mechanisms and established transport dimensions, taking into account rational cutting of elements and minimum consumption steel caused by the conditions of transport and installation of structures;

transfer the maximum amount of finishing work to the factory conditions;

apply industrial solutions for hidden wiring;

at the factory, install window and balcony door blocks in the panels and seal their interfaces with the concrete of the panels;

provide for the factory complete set of individual structural elements into composite mounting elements;

perform the most labor-intensive building elements (sanitary facilities, elevator shafts, waste collection chambers, fences for loggias, bay windows, balconies, etc.) mainly in the form of volumetric elements with full engineering equipment and finishing at the factory.

1.10. Constructive and technological solutions monolithic and precast-monolithic buildings should, as a rule, provide a variety of volumetric-spatial solutions with a minimum of the reduced costs. To this end, it is recommended:

to take into account most fully the features of each method of building construction that affect the volumetric-spatial solutions;

to use the structures of movable formwork, assembled from modular panels;

to design the technology and organization of work simultaneously with the design of the building for the mutual coordination of architectural planning, structural and technological solutions;

to industrialize the production of work as much as possible through the comprehensive mechanization of the processes of manufacturing, transportation, laying and compacting of concrete mixture, the use of prefabricated reinforcement products and mechanization of finishing works;

reduce construction time by ensuring maximum formwork turnover by intensifying the hardening of concrete with positive and negative temperatures outside air;

use formwork and concrete compaction methods that provide minimal additional work to prepare concrete surfaces for finishing.

1.11. In order to reduce fuel consumption for the manufacture of structures and heating the building during its operation, it is recommended:

thermal resistance of external enclosing structures shall be assigned according to economic requirements, taking into account operating costs;

take into account the energy consumption of the production of materials for structures and their manufacture;

by constructive measures to reduce heat loss through openings in walls, joints of prefabricated elements, heat-conducting inclusions, rigid ribs, in layered walls, etc.);

to choose space-planning solutions of the building, allowing to minimize the area of ​​their external fences;

apply roofs with a warm attic.

1.12. To ensure the reliability of structures and assemblies during the life of the building, it is recommended:

use materials for them that have the necessary durability and meet the requirements of maintainability; heat and sound insulation materials and gaskets located in the thickness of the supporting structures must have a service life that corresponds to the service life of the building;

choose Constructive decisions external fences, taking into account the climatic regions of construction;

use combinations of materials in external layered structures, excluding the stratification of concrete layers;

prevent the accumulation of moisture in structures during operation;

assign structural parameters and select physical and mechanical, thermal, acoustic and other characteristics of materials, taking into account the peculiarities of manufacturing technology, installation and operation of structures, as well as possible changes in the properties of materials of structures over time;

assign a class for frost resistance, and, if necessary, a class for water tightness of structures in accordance with the requirements of SNiP 2.03.01-84, II-22-81;

provide for the sequence and procedure for the construction and installation of structures, connections, sealing, insulation and sealing of joints, allowing to ensure their satisfactory operation during the operation of the building;

provide measures to protect against corrosion of structural reinforcement, ties and embedded parts;

elements of structures and engineering equipment, the service life of which is less than the service life of the building (for example, joinery, floor coverings, sealants in joints, etc.), should be designed so that their change does not disturb adjacent structures.

1.13. In the drawings of structural elements (panels, slabs, volumetric blocks, etc.), the design characteristics of the material in terms of strength, frost resistance (if necessary, for water resistance), tempering strength, moisture and density of the material of the building element, schemes of design loads and control tests, must be indicated, as well as tolerances for the manufacture and installation of structures.

with antifreeze additives (potash, sodium nitrite, mixed and other additives that do not corrode the concrete of prefabricated elements), ensuring the hardening of mortar and concrete in frost without heating;

without chemical additives with heating of the erected structures during the time during which the mortar or concrete in the joints gains strength sufficient for the erection of subsequent floors of the building.

The erection of prefabricated buildings by freezing without chemical additives and heating structures is allowed only for buildings with a height of no more than five floors, provided that the calculation of the strength and stability of structures during the first thawing (with the lowest strength of the freshly thawed mortar or concrete), taking into account the actual strength of the mortar (concrete) joints during operation.

In cases where solutions with anti-freeze additives are used, steel ties with an anti-corrosion protective coating of zinc or aluminum must be protected with additional protective coatings.

unheated (the "thermos" method, the use of antifreeze additives);

heating (contact heating, chamber heating);

a combination of non-heating and heating methods. Non-heating methods are recommended to be used at outdoor air temperatures up to minus 15 ° С, and heating methods - up to minus 25 ° С.

The choice of a specific method of erection of monolithic structures in winter is recommended to be made on the basis of technical and economic calculations for local construction conditions.

1.15. In buildings extended in plan, as well as in buildings consisting of volumes of different heights, it is recommended to arrange vertical expansion joints:

temperature - to reduce efforts in structures and limit the opening of cracks in them due to the constraint by the base of temperature and shrinkage deformations of concrete and reinforced concrete structures of the building;

sedimentary - to prevent the formation and opening of cracks in structures due to uneven settlement of foundations caused by the heterogeneity of the geological structure of the foundation along the length of the building, unequal loads on the foundations, as well as cracks that occur at places where the height of the building changes.

It is recommended to perform vertical expansion joints in the form of paired transverse walls located at the border of the planning sections. The transverse walls of vertical joints should, as a rule, be insulated and performed similarly to the structures of the end walls, but without an outer finishing layer. The width of the vertical joints should be determined by calculation, but taken at least 20 mm in the clear.

In order to prevent the ingress and accumulation of snow, moisture and debris, vertical joints are recommended to be closed along the entire perimeter, including the roof, with strips (for example, from corrugated galvanized iron sheets). Cover strips and insulation of vertical seams should not prevent deformation of compartments separated by a seam.

Expansion joints are allowed to be brought to the foundations. Settlement joints should divide the building, including foundations, into insulated compartments.

1.16. The distances between the temperature-shrinkage joints (the lengths of the temperature compartments) are determined by calculation taking into account the climatic conditions of construction, the adopted structural system of the building, the structure and material of walls and floors and their butt joints.

Efforts in the structures of extended buildings can be determined according to "Recommendations for the calculation of structures of large-panel buildings for temperature and humidity effects" (M., Stroyizdat, 1983) or by app. 1 of this Manual.

The distance between the temperature-shrinkage joints of frameless large-panel buildings are rectangular in plan, the design of which meets the requirements of Table. 1, it is allowed to appoint according to table. 2, depending on the value of the annual difference in average daily temperatures t avg. Days, taken equal to the difference between the maximum and minimum average daily temperatures, respectively, of the warmest and coldest months. For the coast and islands of the Arctic and Pacific oceans, this difference should be increased by 10 ° C.

Table 1

	Type I building		Type II building
Constructions		A s, cm 2	Compressive strength class of concrete or mortar grade	Cross-sectional area of ​​longitudinal reinforcement of one floor, A s, cm 2
Exterior walls
Panels: single layer	B3.5 ¾ B7.5		B3.5 ¾ B7.5	4¾ 7 (4¾ 7)
multilayer
vertical		2¾ 4 (5¾ 10)		3 ¾ 5
horizontal
Internal walls
				3 ¾ 5
Overlapping
		25 ¾ 60
Joints (plate-shaped)				¾
Notes: 1. Reinforcement of panels and wall joints is indicated in brackets stairwells. 2. Sectional area of ​​reinforcement A s includes all longitudinal reinforcement of panels and joints (working, structural, mesh).

table 2

Annual change in daily average		Distances between expansion joints of frameless large-panel buildings, m
temperatures, ° С		Type I buildings (according to Table 1) with a step of transverse walls, m, up to		Type II buildings (by
	Batumi, Sukhumi	Not limited	Not limited	Not limited
	Baku, Tbilisi, Yalta
	Ashgabat, Tashkent
	Moscow, Pet-rozavodsk
	Vorkuta, Novosibirsk
	Norilsk, Turukhansk
	Verkhoyansk, Yakutsk
Note. For intermediate temperatures, the distance between expansion joints is determined by interpolation.

Appointment of distances between expansion joints according to table. 2 does not exclude the need for a calculated check of walls and floors in places where they are weakened by large holes and openings, where the concentration of significant temperature forces and deformations is possible (staircases, elevator shafts, driveways, etc.).

In cases where the structural scheme, reinforcement and concrete grade of building structures differ significantly from those provided for in Table. 1, the building should be designed for thermal effects.

1.17. It is recommended to arrange sedimentary joints in cases where uneven subsidence of the base in normal soil conditions exceeds the maximum permissible values ​​regulated by SNiP 2.02.01-83, as well as when the height of the building drops by more than 25%. In the latter case, it is allowed not to arrange a sedimentary seam if, according to the calculation, the strength of the building structures is ensured, and the deformations of the joints of prefabricated elements and the opening of cracks in the structures do not exceed the maximum permissible values.

1.18. In monolithic and precast-monolithic buildings of wall structural systems, temperature-shrinkage, sedimentary and technological seams should be arranged. Technological (working) seams must be arranged to ensure the possibility of concreting monolithic structures with separate grips. Technological seams, as far as possible, should be combined with temperature-shrinkage and settlement seams.

The distance between the temperature-shrinkage seams is determined by calculation or according to table. 3.

Table 3

Structural system	Distance between temperature-shrinkable seams, m, with overlappings
	monolithic
Cross-wall with load-bearing external and internal walls, longitudinal-wall
Cross-wall with non-bearing external walls, cross-wall with separate longitudinal diaphragms
Cross-wall without longitudinal diaphragms
Note. With a frame solution of the first floor, the distance between the temperature-shrinkage joints may be increased by 20%.

2. CONSTRUCTION SYSTEMS

Principles for ensuring the strength, rigidity and stability of residential buildings

2.1. Structural system of the building is a set of interconnected structures of a building that ensure its strength, rigidity and stability.

The adopted structural system of the building must ensure the strength, rigidity and stability of the building at the construction stage and during the operation under the action of all design loads and influences. For prefabricated buildings, it is recommended to provide measures to prevent the progressive (chain) destruction of the load-bearing structures of the building in the event of local destruction of individual structures during emergency impacts (explosions of household gas or other explosive substances, fires, etc.). Calculation and design of large-panel buildings for resistance to progressive destruction are given in Appendix. 2.

2.2. The structural systems of residential buildings are classified according to the type of vertical supporting structures. For residential buildings, the following types of vertical supporting structures are used: walls, frame and trunks (stiffeners), which correspond to wall, frame and trunk structural systems. When applied in one building, several types of each floor vertical structures frame-wall, frame-trunk and trunk-wall systems differ. When the structural system of a building changes according to its height (for example, in the lower floors - a frame, and in the upper floors - a wall), the structural system is called combined.

2.3. Walls, depending on the vertical loads perceived by them, are subdivided into bearing, self-bearing and non-bearing.

Carrier a wall is called, which, in addition to the vertical load from its own weight, perceives and transfers to the foundations loads from floors, roofs, non-bearing external walls, partitions, etc.

Self-supporting is called a wall that perceives and transfers to the foundations a vertical load only from its own weight (including the load from balconies, loggias, bay windows, parapets and other wall elements).

Carrying a wall is called a wall that transfers the vertical load from its own weight to adjacent structures (floors, load-bearing walls, frame) by floor or through several floors. An internal curtain wall is called a partition. In residential buildings, it is generally recommended to use load-bearing and non-load-bearing walls. Self-supporting walls are allowed to be used as insulating walls of risalits, building ends and other elements of external walls. Self-supporting walls can also be used inside a building in the form of ventilation blocks, lift shafts and similar elements with engineering equipment.

2.4. Depending on the layout of the load-bearing walls in the building plan and the nature of the floors supported on them (Fig. 3), the following structural systems are distinguished:

cross-wall with transverse and longitudinal load-bearing walls;

cross-wall - with transverse load-bearing walls;

longitudinal-wall - with longitudinal load-bearing walls.

Rice. 3. Wall structural systems

a - cross-wall; b- cross-wall; v - longitudinal-wall with ceilings

I - low-span; II- medium-span; III- large-span

1 - curtain wall; 2 — bearing wall

In buildings with a cross-wall structural system, the outer walls are designed to be load-bearing or non-load-bearing (hinged), and the floor slabs are designed as supported along the contour or three sides. The high spatial rigidity of the multi-cell system formed by floors, transverse and longitudinal walls contributes to the redistribution of forces in it and a decrease in stresses in individual elements... Therefore, the buildings of the cross-wall structural system can be designed with a height of up to 25 floors.

In buildings with a transverse-wall structural system, vertical loads from floors and curtain walls are transmitted mainly to the transverse load-bearing walls, and floor slabs operate mainly according to a beam scheme with support on two opposite sides. Horizontal loads acting parallel to the transverse walls are absorbed by these walls. Horizontal loads acting perpendicular to the transverse walls are perceived by: longitudinal stiffening diaphragms; flat frame due to rigid connection of transverse walls and floor slabs; radial transverse walls at complex form building plan.

Longitudinal diaphragms of rigidity can serve as longitudinal walls of staircases, separate sections of longitudinal external and internal walls. It is recommended that the adjacent floor slabs be supported on longitudinal diaphragms, which improves the operation of the diaphragms against horizontal loads and increases the rigidity of the floors and the building as a whole.

It is recommended to design buildings with transverse load-bearing walls and longitudinal stiffening diaphragms up to 17 storeys high. In the absence of longitudinal stiffening diaphragms in the case of a rigid connection of monolithic walls and floor slabs, it is recommended to design buildings with a height of no more than 10 floors.

Buildings with radially spaced transverse walls with monolithic ceilings can be designed up to 25 storeys high. It is recommended to place temperature-shrinkage joints between sections of an extended building with radially located walls so that horizontal loads are perceived by walls located in the plane of their action or at a certain angle. For this purpose, it is necessary to provide special dampers in the temperature-shrinkage joints, which work pliable under temperature-shrinkage effects and rigidly - under wind loads.

In buildings of a longitudinal-wall structural system, vertical loads are perceived and transmitted to the base by longitudinal walls, on which the ceilings are supported, working mainly according to the beam scheme. For the perception of horizontal loads acting perpendicular to the longitudinal walls, it is necessary to provide vertical stiffening diaphragms. Such diaphragms of stiffness in buildings with longitudinal load-bearing walls can be transverse walls of staircases, end walls, intersectional ones, etc. The floor slabs adjacent to the vertical stiffness diaphragms are recommended to be supported on them. It is recommended to design such buildings with a height of no more than 17 floors.

When designing buildings of transverse-wall and longitudinal-wall structural systems, it is necessary to take into account that parallel load-bearing walls, united by only floor disks, cannot redistribute vertical loads among themselves. To ensure the stability of the walls in case of emergency impacts (fire, gas explosion), it is recommended to provide for the participation of walls in a perpendicular direction. With external load-bearing walls made of non-concrete materials (for example, from laminated panels with sheet sheathing), it is recommended to position the longitudinal stiffening diaphragms so that they at least in pairs connect the transverse walls. In insulated load-bearing walls, it is recommended to provide vertical ties in horizontal joints and joints.

2.5. In frame structural systems, the main vertical supporting structures are the frame columns, to which the load is transferred from the floors directly (girder-free frame) or through the girders (girder frame). The strength, stability and spatial rigidity of frame buildings is ensured by the joint work of floors and vertical structures. Depending on the type of vertical structures used to ensure strength, stability and rigidity, there are braced, frame and frame-braced frame systems (Fig. 4).

Rice. 4. Frame structural systems

a, b- connected with vertical stiffness diaphragms; v - the same, with a distribution grillage in the plane of the vertical stiffening diaphragm; G- frame; d- frame-connected with vertical stiffness diaphragms; e — the same, with rigid inserts

1 - vertical stiffness diaphragm; 2 — frame with hinge nodes; 3 — distribution grillage; 4 — frame frame; 5 — rigid inserts

With a braced frame system, a girder-free frame or a girder frame with non-rigid girder nodes with columns is used. With non-rigid nodes, the frame practically does not participate in the perception of horizontal loads (except for columns adjacent to vertical stiffness diaphragms), which makes it possible to simplify the design solutions for the frame nodes, use the same type of crossbars over the entire height of the building, and design the columns as elements working mainly in compression. Horizontal loads from floors are perceived and transmitted to the base by vertical stiffening diaphragms in the form of walls or through diagonal elements, the belts of which are columns (see Fig. 4). To reduce the required number of vertical stiffness diaphragms, it is recommended to design them with a non-rectangular shape in the plan (corner, channel, etc.). For the same purpose, the columns located in the plane of the vertical stiffening diaphragms can be united by distribution grillages located at the top of the building, as well as at intermediate levels along the height of the building.

In a frame frame system, vertical and horizontal loads are absorbed and transferred to the base by a frame with rigid nodes of crossbars with columns. Frame frame systems are recommended for low-rise buildings.

In a frame-braced frame system, vertical and horizontal loads are perceived and transferred to the base jointly by vertical stiffening diaphragms and a frame frame with rigid nodes of girders with columns. Instead of through vertical stiffening diaphragms, rigid inserts can be used to fill individual cells between the girders and columns. Frame-braced frame systems are recommended to be used if it is necessary to reduce the number of stiffening diaphragms required for the perception of horizontal loads.

In frame buildings of tie and frame-tie structural systems, along with stiffening diaphragms, spatial elements of a closed shape in the plan, called trunks, can be used. Frame buildings with stiffening trunks are called frame-trunked.

Frame buildings, the vertical load-bearing structures of which are the frame and load-bearing walls (for example, external, intersectional, staircase walls) are called frame-wall. It is recommended to design buildings of the frame-wall structural system with a non-girder frame or with a girder frame having non-rigid joints between girders and columns.

2.6. In shaft structural systems, the vertical supporting structures are shafts formed mainly by the walls of the staircase-elevator shafts, on which the ceilings are supported directly or through distribution grillages. According to the method of supporting the interfloor floors, there are trunk systems with cantilever, stacked and suspended support of the floors (Fig. 5).

Rice. 5. Barrel structural systems (with one bearing barrel)

a, b- console; v, G - whatnot; d, f - suspended

1 — bearing trunk; 2 — cantilever overlap; 3 — a floor-high console; 4 — cantilever bridge; 5 — grillage; 6 - suspension

Large-panel buildings

For low-span ceilings, it is recommended to use a cross-wall structural system. It is recommended to assign the dimensions of structural cells so that the floor slabs rest on the walls along the contour or on three sides (two long and one short).

For medium-span ceilings, cross-wall, cross-wall or longitudinal-wall structural systems can be used.

In case of a cross-wall structural system, it is recommended to design external walls as load-bearing, and assign the dimensions of structural cells so that each of them is overlapped by one or two floor slabs.

With a cross-wall structural system, the external longitudinal walls are designed as non-bearing. In buildings of such a system, it is recommended to design load-bearing transverse walls through the entire width of the building, and position the internal longitudinal walls so that they at least pairwise combine the transverse walls.

With a longitudinal-wall structural system, all external walls are designed to be load-bearing. The step of the transverse walls, which are transverse stiffness diaphragms, must be justified by calculation and take no more than 24 m.

2.8. In large-panel buildings, for the perception of forces acting in the plane of horizontal stiffening diaphragms, precast concrete floor slabs and coatings are recommended to be interconnected with at least two ties along each face. It is recommended to take the distance between the ties not more than 3.0 m. The required cross-section of the ties is assigned by calculation. It is recommended that the cross-section of the ties be taken in such a way (Fig. 6) that they ensure the perception of tensile forces not less than the following values:

for ties located in the ceilings along the length of the building extended in the plan - 15 kN (1.5 tf) per 1 m of the building width;

for ties located in the ceilings perpendicular to the length of a building extended in the plan, as well as ties of compact buildings, - 10 kN (1 tf) per 1 m of the building length.

Rice. 6. Layout of connections in a large-panel building

1 — between panels of external and internal walls; 2 — the same for longitudinal external load-bearing walls; 3 - longitudinal internal walls; 4 — the same for transverse and longitudinal internal walls; 5 — the same for exterior walls and floor slabs; 6 — between floor slabs along the length of the building; 7 - the same, across the length of the building

On the vertical edges of prefabricated slabs, it is recommended to provide key joints that resist mutual displacement of the slabs across and along the joint. Shear forces at the joints of floor slabs resting on load-bearing walls can be perceived without the installation of dowels and ties, if the constructive solution of the junction of the floor slabs with the walls ensures their joint work due to friction forces.

It is recommended to provide key joints and metal horizontal ties in vertical joints of load-bearing wall panels. It is recommended to connect concrete and reinforced concrete panels of outer walls in at least two levels (at the top and bottom of the floor) with ties with internal structures designed to absorb the pull-off forces within the height of one floor at least 10 kN (1 tf) per 1 m length outer wall along the facade.

With self-wedging joints of external and internal walls, for example, of the “dovetail” type, ties can be provided only in one floor level and the value of the minimum tie force can be halved.

Wall panels located in the same plane are allowed to be connected with ties only at the top. It is recommended to designate the bond cross-section for the perception of a tensile force of at least 50 kN (5 tf). In the presence of links between wall panels located one above the other, as well as shear links between wall panels and floor slabs, horizontal links in vertical joints may not be provided if they are not required by calculation.

in walls, for which, according to the calculation, through vertical reinforcement is required to perceive tensile forces arising from the bending of the wall in its own plane;

to ensure the stability of the building against progressive destruction, if other measures fail to localize the destruction from emergency special loads (see clause 2.1). In this case, vertical ties wall panels in horizontal joints (interfloor connections), it is recommended to assign from the condition of their perception of tensile forces from the weight of the wall panel and floor slabs supported on it, including the load from the floor and partitions. As such connections, it is recommended, as a rule, to use parts for lifting panels;

in carriers panel walls ah, which are not directly adjacent to concrete walls in a perpendicular direction.

2.9. It is recommended to design connections of prefabricated elements in the form of welded reinforcing bars or embedded parts; reinforcing loop outlets embedded in concrete, connected without welding; bolted connections. The connections should be located so that they do not interfere with the high-quality monolithing of the joints.

Steel ties and embedded parts must be protected from fire and corrosion. Fire protection must ensure the strength of the joints for a time equal to the value of the required fire resistance of the structure, which are connected by the designed ties.

2.10. Horizontal joints of panel walls should ensure the transfer of forces from eccentric compression from the plane of the wall, as well as from bending and shear in the plane of the wall. Depending on the nature of the support of the floors, the following types of horizontal joints are distinguished: platform, monolithic, contact and combined. At the platform joint, the compressive vertical load is transmitted through the support sections of the floor slabs and two horizontal mortar joints. In a monolithic joint, the compressive load is transmitted through a layer of monolithic concrete (mortar) laid in the cavity between the ends of the floor slabs. In the contact joint, the compressive load is transmitted directly through the mortar joint or elastic spacer between the abutting surfaces of the precast wall elements.

Horizontal joints in which compressive loads are transmitted through sections of two or more types are called combined joints.

Platform joint(Fig. 7) is recommended as a basic solution for panel walls with double-sided support of floor slabs, as well as with one-sided support of slabs to a depth of at least 0.75 of the wall thickness. It is recommended to designate the thickness of horizontal mortar joints based on the calculation of the accuracy of manufacturing and installation of prefabricated structures. If the accuracy is not calculated, then the thickness of the mortar joints is recommended to be set equal to 20 mm; the size of the gap between the ends of the floor slabs is taken at least 20 mm.

rice. 7 Platform joints of prefabricated walls

a- external three-layer panels with flexible bonds between layers; b¾ internal walls with double-sided support of floor slabs; v¾ the same, with one-sided support of floor slabs

It is recommended to grout the joint after installing the upper floor panel on mounting brackets or concrete protrusions from the body of the wall panels. Lower part the wall panel must be installed below the embedment level by at least 20 mm.

Contact joint(Figure 9) it is recommended to use it when the floor slabs are supported on cantilever wall extensions or with the help of cantilever protrusions ("fingers") of the slabs. At contact joints, floor slabs can be supported on walls without mortar (dry). In this case, to ensure sound insulation, the cavity between the ends of the slabs and the walls must be filled with mortar and reinforcement ties must be provided that turn the prefabricated floor into a horizontal stiffness diaphragm.

Rice. 9. Contact joints of prefabricated walls with the support of floor slabs on

a— v- "fingers"; G— e- wall consoles

In the combined platform-monolithic joint (see fig. 8, v) the vertical load is transmitted through the supporting sections of the floor slabs and the concrete for embedding the joint cavity between the ends of the floor slabs. With a platform-monolithic joint, prefabricated floor slabs can be designed as continuous. To ensure the continuity of the floor slabs, it is necessary to connect to each other on the supports by welded or looped ties, the section of which is determined by calculation.

To ensure high-quality filling of the cavity between the ends of floor slabs with a platform-monolithic joint, the thickness of the gap at the top of the slab is recommended to be at least 40 mm, and at the bottom of the slabs - 20 mm. With a gap thickness of less than 40 mm, it is recommended to design the joint as a platform joint.

The cavity for embedding the joint along the length of the wall can be continuous (see Fig. 8, c, d) or intermittent (see fig. 8, d). The intermittent scheme is used for point support of floor slabs on the walls (with the help of support "fingers"). In case of a platform-monolithic joint above and below the floor slab, it is necessary to arrange horizontal mortar joints.

The structural solution of a monolithic joint must ensure its reliable filling with a concrete mixture, including at subzero air temperatures. The strength of the concrete for embedding the joint is assigned by calculation.

In the combined contact platform at the junction, the vertical load is transmitted through two support platforms: contact (in the place of direct support of the wall panel through the mortar joint) and platform (through the support sections of the floor slabs). The contact-platform joint is recommended mainly for one-sided support of floor slabs on walls (Fig. 10). The thickness of mortar joints is recommended to be assigned in the same way as the joints in the platform joint.

Rice. 10. Contact-platform joints of prefabricated walls

a - outdoor; b, c- internal

It is recommended to designate the design grades of the horizontal joint mortar according to the calculation for force effects, but not lower: grade 50 - for installation conditions at positive temperatures, grade 100 - for installation conditions at negative temperatures. It is recommended to assign the class of concrete for the compressive strength of the embedment of the horizontal joint not lower than the corresponding class of concrete of the wall panels.

2.11. Shear forces in horizontal joints of panel walls during construction in non-seismic regions are recommended to be perceived due to the resistance of friction forces.

Shear forces in vertical joints of panel walls are recommended to be perceived in one of the following ways:

concrete or reinforced concrete dowels formed by embedding the joint cavity with concrete (Fig. 11, a, b);

keyless connections in the form of reinforcing outlets from panels embedded in concrete (Fig. 11, v);

embedded parts welded together, anchored in the body of the panels (Fig. 11, G).

Rice. 11. Schemes for the perception of shear forces in the vertical joint of panel walls

a, b- dowels; v- monolithic reinforcement ties; G- welding of embedded parts

1 - welded reinforcement connection; 2 — the same, loop; 3 — pad welded to embedded parts

A combined method of perceiving shear forces is possible, for example, with concrete dowels and floor slabs.

It is recommended to design the dowels in a trapezoidal shape (Fig. 12). It is recommended to take the depth of the key not less than 20 mm, and the angle of inclination of the crushing area to the direction perpendicular to the shear plane, not more than 30 °. Minimum size in terms of the plane of the joint, through which the joint is monolithic, it is recommended to take at least 80 mm. Provision should be made for the compaction of concrete at the joint with a deep vibrator.

Rice. 12. Types of vertical joints of panel walls

a- flat; b- profiled keyless; v- profiled keyway; 1 - soundproofing pad; 2 — solution; 3 — joint embedment concrete

In keyless joints, shear forces are perceived by welded or looped bonds embedded in concrete in the cavity of the vertical joint. Keyless connections require an increased (in comparison with keyed connections) consumption of reinforcing steel.

Welded joints of panels on embedded parts are allowed to be used at the joints of walls for areas with harsh and cold climates in order to reduce or eliminate monolithic work on the construction site. At the joints of the outer walls with the inner ones, the welded joints of the panels on the embedded parts should be located outside the zone where moisture condensation is possible with a temperature difference along the wall thickness.

Volume-block and panel-block buildings

2.12. It is recommended to design volume-block buildings from supporting volumetric blocks supported on each other (see clause 1.4). Carrying blocks can be linear or point supported. With linear support, the load from the structures located above is transferred along the entire perimeter of the volumetric block, to three or two opposite sides of it. With point support, the load is transmitted mainly along the corners of the volumetric block.

When choosing a method of supporting bulk blocks, it is recommended to take into account that a linear support scheme allows more full use of the bearing capacity of the walls of the block and, therefore, is preferable for multi-storey buildings.

2.13. It is recommended to provide the strength, spatial rigidity and stability of volume-block buildings with the resistance of individual pillars of volumetric blocks (flexible structural system) or the joint work of pillars from volumetric blocks interconnected (rigid structural system).

With a flexible structural system, each column of volumetric blocks must fully absorb the loads falling on it, therefore, according to strength conditions, volumetric blocks of adjacent columns cannot be connected to each other along vertical joints (in order to ensure sound insulation along the contour of the openings between the blocks, it is necessary to provide for the installation of sealing gaskets) ...

To limit the deformations of the joints in case of uneven deformations of the base and other influences, it is recommended to connect the volume blocks to each other at the level of their top with metal ties and to prevent mutual displacements of the blocks along the vertical joints at the level of the basement-foundation part of the building.

With a rigid structural system, the pillars of the volumetric blocks must have design connections at the floor level and keyed monolithic connections in vertical joints. In buildings of a rigid structural system, all pillars of volumetric blocks work together, which ensures a more even distribution of forces between them from external loads and influences. It is recommended to use a rigid structural system for buildings with a height of more than ten floors, as well as for any number of storeys, when uneven deformations of the base are possible. With a rigid structural system, the coaxial arrangement of the volumetric blocks in the building plan is recommended.

2.14. It is recommended to design the nodes of volumetric blocks (Fig. 13) in such a way as to maximize the bearing area of ​​the elements, but at the same time to exclude or, if possible, reduce the influence of geometric eccentricities arising from the misalignment of the geometric centers of the horizontal sections of the walls and the application of vertical loads in the seams. It is recommended to take the thickness of mortar joints equal to 20 mm.

Rice. 13. Horizontal joints of volume-block buildings

a- blocks of the "lying glass" type; b ¾ cap type block; 1 ¾ sealing gasket; 2 - insulating element; 3 — solution; 4 — the wall of the "cap" -type block; 5 ¾ external wall panel; 6 ¾ the wall of the block of the "lying glass" type; 7 - reinforcing mesh; 8 - joint sealant

Tensile-compressive forces in vertical joints of blocks can be perceived using welded embedded parts or through concrete monolithic seams.

It is recommended to perceive shear forces between adjacent pillars of blocks with concrete or reinforced concrete joints.

For the transfer of shear forces in the upper floors, it is recommended to use: keyed seams formed by the corresponding profiles of the upper and lower supporting surfaces of the blocks and squeezing out the mortar of the horizontal seams during the assembly of the blocks;

blocks with ribs up, arranged along the contour of the ceiling panel, entering during installation inside the contour ribs of the floor panel of the upper floor, with partial filling of the gap with cement mortar;

constant compression of horizontal seams and the use of friction by tensioning the reinforcement (strands) in the wells between the blocks;

special rigid elements (for example, rolled profiles) inserted in the gaps between blocks.

For the device of vertical shear links, it is recommended to arrange vertical reinforced keyed joints, for the device of which on the vertical edges of the blocks, reinforcing outlets should be provided, which are connected to each other by welding using special combs and other devices. When creating keyway joints, it is necessary to provide for cavities sufficient for controlled and reliable placement of concrete with a cross section of at least 25 cm and a width of 12 - 14 cm.

2.15. A panel-block building is a combination of load-bearing volumetric blocks and plane structures (wall panels, floor slabs, etc.). It is recommended to designate the dimensions of volumetric blocks based on the conditions for using assembly cranes used in large-panel housing construction. It is recommended to predominantly place premises in volumetric blocks saturated with engineering and built-in equipment (kitchens, sanitary facilities with walk-through locks, stairs, elevator shafts, elevator engine rooms, etc.).

When designing panel-block buildings, it is recommended to provide for inter-series unification of volumetric blocks and maximize the use of large-panel housing construction products.

2.16. Panel-block buildings are recommended to design a wall structural system with precast floor slabs supported on wall panels and (or) load-bearing volumetric blocks. The support of the floor slab on the volumetric block is recommended in the following ways (Fig. 14): on the cantilever protrusion at the top of the volumetric block; directly onto the volumetric block.

Rice. 14. Horizontal joints of panel-block buildings with the support of the floor slab

a- with the help of the supporting "fingers" of the floor slabs; b, v - on the cantilever protrusion at the top of the volumetric block

1 - floor slab of the volumetric block; 2 - floor slab with supporting "fingers"; 3 — volumetric block ceiling plate; 4 — floor slab with undercut on the support; 5 - ceiling slab of the volumetric block with a console for supporting the floor slab; 6 - shortened floor slab

When choosing the method of supporting the floor slab on the volumetric block, it is recommended to take into account that the support of the slabs on the cantilever protrusions (Fig. 14, v) provides a clear scheme for the transfer of vertical loads from the above-located volumetric blocks, but requires the use of shortened floor slabs, and the presence of a cantilever protrusion at the top of the block worsens the interior of the room and causes the device of cutouts in the partitions adjacent to the volumetric block. Supporting the plates directly on the volumetric block (Fig. 14, G) allows you to avoid the device of cantilever protrusions, but the design of the interface of the volumetric blocks becomes more complicated.

2.17. The strength, spatial rigidity and stability of panel-block buildings are recommended to be ensured by the joint operation of the pillars of volumetric blocks, load-bearing wall panels and floor slabs, which must be interconnected by design metal ties. It is recommended to assign the minimum cross-section of ties according to the instructions in clause 2.8. When the floor slabs are supported only on the volumetric blocks, it is allowed to assume that each of the pillars of the volumetric blocks perceives only the loads falling on it.

2.18. The face of the volumetric block, on the sides of which the floor slab rests, is recommended to be located in the same plane with the faces of the wall panels.

When designing a special panel-block series (without the need for interchangeability of the walls of panels and volumetric blocks), it is possible to bind the elements according to Fig. fourteen, a, v, which makes it possible to do without shortening the floor slabs.

Expansion joint is a seam with a width of at least 20 mm, dividing the building into separate compartments. Thanks to this dissection, each section of the building receives the possibility of independent deformations.

The purpose of the expansion joint is to lower the overload on individual parts of the systems in the places of alleged distortions, which have every chance of being created during the staggering of weightless temperature, as well as seismic phenomena, sudden and uneven sedimentation of the soil and other actions that can start personal overloads that lower the bearing characteristics of the systems ... In visual intent, probably a section in the body of the building, he divides the building into a certain number of blocks, giving them some elasticity to the building. For the supply of waterproofing, the cross-section is filled with the suitable one that was used. Probably, different sealants, waterstops or putties have all the chances to exist.

Expansion joints are divided into three main types

Depending on the purpose, expansion joints are divided into three main types: - temperature-shrinkage joints are arranged in order to avoid the formation of cracks and distortions in the outer walls of buildings due to changes in air temperatures outside and inside the building. Seams of this type cut through the structures of only the ground part of the building - walls, floors, coverings and ensure the independence of their horizontal movements relative to each other. At the same time, foundations and other underground parts of the building are not dissected, since temperature drops for them are less and deformations do not reach dangerous values.

The device of the expansion joint is the privilege of the most experienced builders, therefore this serious craft should be entrusted only to competent specialists. The construction team is obliged to own the noble rigging of the knowledgeable installation of the expansion joint, from this it depends on the survivability of the operation of the whole system. It is necessary to predict the future of affairs without a break, connecting fitter's, welded, carpentry, reinforcing, trigonometric, concrete laying. The design of the expansion joint assembly should be in accordance with generally accepted, deliberately researched advice.

Expansion joint - Wikipedia: Expansion joint - designed to reduce loads on structural elements in places of possible deformations arising from fluctuations in air temperature, seismic phenomena, uneven soil settlement and other influences that can cause dangerous intrinsic loads that reduce the bearing capacity of structures. It is a kind of cut in the structure of the building, dividing the structure into separate blocks and, thereby, giving the structure a certain degree of elasticity. For sealing purposes, it is filled with an elastic insulating material.

Distances between temperature and shrinkage joints

The distances between the temperature and shrinkage joints are assigned depending on the climatic conditions of the construction site and the material of the outer walls of the building. For example, in residential buildings, this distance is 40? 100 m at brick walls and 75? 150 m with walls made of concrete panels (the lower the outside air temperature at the construction site of the building, the smaller the distance is assigned between the expansion joints). The compartment of the building located between two temperature-shrink joints or between the end of the building and the seam is called a temperature compartment or temperature block;

Rational cutting

In what episode do the main distortions of the concreted buildings occur? What are expansion joints in this case? Configurations in the body of the building have all the chances to happen at the time of construction near a great temperature effort - a consequence of the exotherm of the hardening concrete and the fluctuation of the temperature of the spirit. To this, after all, in this episode the concrete is shrinking. At the reinforced concrete moment, expansion joints are ready to reduce unnecessary overloads and prevent subsequent configurations that can start inevitable about construction. It is as if the structures are cut according to their length into single collapsible installations. Expansion joints work to provide high-quality functioning of any section, and also eliminate the possibility of stress between adjacent blocks.

The more popular types are expansion joints and expansion joints. They are used around the pacifying bulk of the erection of various buildings. Expansion joints will compensate for hull and building configurations that occur around temperature changes around the circle. In a huge step, the manure shot of the structure is subjected to this, therefore, the cuts are made from the value of the soil to the roof, thus most without affecting the solid shot. This type of seam cuts the structure into an installation, such a role, providing the possibility of rectilinear movements in the absence of negative (unrestrained) results.

Does one or the other visit expansion joints between houses? Specialists systematize them according to the line of indicators. Probably, the type of the serviced system, the space of the location (device), for example, expansion joints in the walls of the structure, in the floors, in the roof, has the opportunity to exist. Apart from this, it is necessary to take into account the sociability and regime of their location (inside the building and outside, in an open atmosphere). Much has been spoken about the generally accepted systematization (more fundamental, embracing the more distinctive symptoms of the deformation seam without ever leaving). Sympathy started in the base of the distributions, with which it is called to fight. From this point of view, the deformation stitch between houses has the ability to exist thermal, silt, heat shrink, earth-shrinkable, insulating. Due to the current events and the criterion between houses, different future expansion joints are used. But one should be aware that they are obliged to fit the characteristics given at the beginning without a break.

Sedimentary seams

- Settlement joints are provided in cases where uneven and uneven settlement of adjacent parts of the building is expected. Such a settlement can occur when the height differences of individual parts of the building are more than 10 m, with different loads on the base, as well as with dissimilar soils under the foundations.
Rice. 3.67. Diagrams of the device of expansion joints in buildings: a - temperature-shrinkage; b - sedimentary: 1 - overground part of the building; 2 - underground part (foundation); 3 - expansion joint Sedimentary joints dissect vertically all structures of the building, including its underground part. This allows you to provide an independent draft of individual volumes of the building. Settlement seams provide not only vertical, but also horizontal displacement of the dismembered parts, so they can be combined with temperature-shrinkage seams. This type of expansion joints is called temperature-sedimentary; - anti-seismic seams are provided in buildings located in earthquake-prone areas. The antiseismic seam, just like the sedimentary seam, dismembers the building along its entire height (aboveground and underground parts) into separate compartments, which are independent stable volumes, which ensures their independent settlement.

seam 1	seam 2	seam 3
44% concrete	27% concrete	56% concrete
structure 18	structure 134	structure 1903

All kinds of systems and buildings are subjected to destruction according to various factors: the sedimentation of the structure after erection during operation, temperature and seismic actions, the heterogeneity of soils at the base of the systems. Of course, when designing and building, you need to take into account all these reasons and make the item very harmless to people, and also reduce the likelihood of defects and the risk of frequent repairs. Since in the modern world, more and more often, huge and powerful buildings are being erected as residential, that way and commercial, industrial, it is unrealistic to stand up in the absence of the introduction of expansion joints in all the fruitful details of buildings.

In reinforced concrete and stone structures of considerable length, dangerous natural stresses appear from shrinkage and temperature effects, as well as due to uneven settlement of foundations. An example is the exterior walls of buildings, which periodically receive increasing tensile or compressive deformations during seasonal temperature changes. As a result, the walls of the building can burst into two or more parts, depending on the length of the building. Additional stresses in structures from uneven settlement of supports arise when the foundations of buildings are placed on dissimilar soils or with unequal pressures of foundations on the foundations.

In order to reduce their own stresses from temperature differences, shrinkage of concrete and settlement of supports, reinforced concrete and stone structures of buildings are divided in length and width into separate parts (deformation blocks) by temperature-shrinkage and settlement seams. Heat-shrinkable joints cut buildings to the top of the foundation, and sedimentary joints - including the foundation. This is due to the fact that the temperature and humidity conditions of the foundations fluctuate insignificantly, therefore, small natural stresses arise in it from shrinkage and temperature drops. In buildings made of in-situ concrete, expansion joints are at the same time working joints, i.e., places for interrupting concrete placement for a long time.

The total width of the expansion joints depends on the size of the expansion blocks of the building and possible temperature fluctuations. Calculations show that when erecting buildings at an average temperature, their deformation blocks can be separated by seams 0.5 cm wide; they can even come into close contact, since due to concrete shrinkage, the seams themselves will open and form a gap sufficient to lengthen the longitudinal structures of the blocks with increasing temperature. If the structures are erected at a relatively low temperature, then the width of the seam is usually taken 2 ... 3 cm.

Buildings or structures that are rectangular in plan are usually divided into equal parts by seams. In buildings with outbuildings, it is convenient to place expansion joints in the incoming corners; with different number of storeys - in conjunction with a low part with a high one (Fig. 148), and when new buildings or structures are adjacent to old ones - in the places of adjoining. In seismic areas, expansion joints are also used as anti-seismic ones.

Expansion joints in the enclosing structures are solved in a relatively similar way, which cannot be said about the structures of the supporting frame. The simplest constructive solutions for expansion joints. In one-story buildings, this is achieved by arranging paired columns.

Expansion joints in frame buildings are most often formed by installing double columns and paired beams (Fig. 149, a). Such joints are the most expensive and are recommended for high-rise buildings with heavy or dynamic loads. In panel buildings, seams are made by setting paired transverse walls. When supporting the floor beams on the walls, it is advisable to arrange the expansion joint using a sliding support (Fig. 149.6).

In monolithic reinforced concrete structures the expansion joints are arranged by freely supporting the end of the beam of one part of the buildings on the cantilever of the beam of the other part of the building (Fig. 149, c);

in cantilever expansion joints, the contacting parts must be strictly horizontal, since otherwise, due to the seam jamming, both the console and the part of the beam lying on it can be damaged (Fig. 150, a). Reverse slope of the support surface of the console is especially dangerous. Exemplary designs of expansion joints in walls and ceilings are shown in Fig. 150, in, g.

Sedimentary seams (when new buildings adjoin old ones, at the junctions of high parts of a building with low ones, when erecting buildings on heterogeneous and subsiding soils) are arranged by means of paired columns resting on independent foundations, or installed in the gap between two parts of the building (with independent foundations ) freely supported liner slabs or beam structures (Fig. 150.6). The latter solution is most often used for prefabricated structures.

Proper home insulation and expansion joints in particular, the opportunity in our, not easy time, to save on heating by 2-4 times. Heating is an expensive pleasure and we have to save money while looking for more and more new opportunities.

To date, many have already begun this urgent work, but how to do it correctly? Let's go in order ?!

What is an expansion joint?

The problem exists

Thermal insulation of the expansion joint is one of the most difficult sections in the insulation of multi-storey residential buildings: the installer has practically no opportunity to get to the walls from the outside (the gap does not allow), and the methods invented earlier are not economically feasible today.
Many people make a common mistake: they insulate the walls in contact with the expansion joint from the inside. This is absolutely impossible to do, because the dew point shifts closer to the inner edge of the walls, which leads to their getting wet and moldy. But we breathe all this !!!

Why insulate it?

It is not uncommon for people to complain that cold penetrates into this gap between structures and the walls inside industrial and residential buildings are cold.
A hard-to-reach expansion joint in winter, when exposed to low temperatures and a walking wind, is not protected in any way, and therefore precious heat is lost, and the cost of heating the room increases.

Is this work necessary? It's up to you to judge and decide.

• Energy savings of about 30% per heating season.
• The soundproofing of the building is improved.
• Rise in indoor temperature.
• Eliminate the conditions for the appearance of dampness and mold.

Our company offers a new approach to solving this problem.
We offer insulation of expansion joints using polyurethane foam (PPU)

Polyurethane foam (PPU)- strong, lightweight and durable thermal insulation material... PPU does not shrink, it can expand and contract depending on climatic conditions, which means it will last longer and retain its direct function.

Manufacturing takes place directly at the construction site, when two components, when mixed in compliance with the required proportion, enter into a chemical reaction, are sprayed onto the surface, within 3-5 seconds they foamed 30 - 150 times and hardened. It has high density, which means it will become a reliable protector from dampness, even if there are damages on the walls. Low coefficient of thermal conductivity, high noise insulation properties .

Thermal joint insulation technology

Before starting work, a team of professional installers covers the walls with a protective film to avoid contamination. Fitters, using special equipment, rise to the required height.

Further, work begins directly on the insulation of the thermal seam. The main advantage of thermal insulation with the use of polyurethane foam is the ability to seal the expansion joint only along the perimeter, without completely filling it. This approach creates a closed air space inside the seam and protects it from drafts, keeping warm air inside.
Technologically, it looks like this: Layer by layer, two opposite walls of the expansion joint are sprayed until the gap between the layers becomes 5-10 cm. Further, the spraying is done again, already from above, pulling the gap completely from beginning to end. At the end of the work, the expansion joint itself is closed with a corrugated galvanized sheet. The effectiveness of this technology is that it is seamless, completely solves the problem, and is inexpensive..

The best solution to the problem

Today everyone understands that saving is a necessity. It is not known how much and how quickly the tariffs for housing and communal services will grow in the future, you will finally stop paying monthly overpayments, you will be able to live in comfort and warmth, and most importantly, you will get rid of the “cold wall” problem once and for all. We have found the optimal, and most importantly, economically profitable solution problems of thermal insulation of the building.

To insulate expansion joints, you will need the help of our specialists who will make accurate calculations cost and effect of insulation, efficiently and on time will carry out the necessary work.
Take up this issue in advance, in the summer, since the technology is used only at an air temperature of more than 15 C.