Crossbarless reinforced concrete frame systems in modern construction
Prefabricated reinforced concrete frame "KUB-2.5" is a universal design for the construction of residential, public and industrial buildings both under normal construction conditions and in areas with seismic activity of not more than 9 points inclusive on a 12 point scale. The universal constructive system "KUB-2.5" makes it possible, in a variety of climatic, relief, seismic conditions, to almost completely ensure the construction of residential buildings, buildings for social and cultural purposes, warehouse complexes, multi-storey car parks, etc. - i.e. to implement residential development and objects of the industrial and communal zone with it in a single constructive key, in a single technology for the manufacture and installation of building structures.
Residential buildings, social facilities, administrative buildings - tens and hundreds of objects have been erected during this time using a frameless frame in many cities of Russia and the CIS - Moscow, St. Petersburg, Nizhny Novgorod, Kiev and many other cities.
Picture 1
Axonometric view of load-bearing structures
a) and diagrams of moments (b) of the crossbarless frame "Cube-2.5": NK - over-column slab; MK - intercolumn plate; PVC - plate insert; K-column
To date, the KUB-2.5 constructive building system of the crossbarless frame is the only building system on the Russian market in which the frame is prefabricated, only the joints between the structural elements of the frame are monolithic: a column and a slab. This makes it promising to use it in the conditions of the North, where the use of monolithic reinforced concrete is limited by natural factors. The factory technology for manufacturing building elements used in this system transfers the labor costs of builders to the workshop conditions to the maximum, thereby significantly reducing the risks of both natural and human factors at the construction site, and also significantly reduces construction time.
The design of the crossbarless frame of the KUB-2.5 system is a frame (frame-braced) precast-monolithic frame with no-capped ceilings (Fig. 1, a). The division of the floor is designed in such a way that the panel joints are located in areas where the magnitude of the bending moments is equal to zero (Fig. 1b). Spatial rigidity is provided by a monolithic connection of elements (floors and columns) and, if necessary, by the inclusion of connections or diaphragms in the system.
The developed frame structures provide for floor heights of 2.8 m, 3.0 m, and 3.3 m with the main grid of columns 6.0 x 6.0 m. Span of 3.0 m, 6.0 m and 12.0 m is possible.
Figure 2 Options for external enclosing structures of the Kub-2.5 frameless frame
The structural system of the frameless frame has 2 bearing elements: a column and a floor panel, which makes it possible to carry out external enclosing structures in various versions. According to the static function, external walls can be either hinged (Fig. 2, a-b) or self-supporting (Fig. 2, c). According to the material - concrete, foam blocks, brick. Insulation can be located both on the inside and on the outside, including with the use of ventilated facades. Structures made of various materials can also be used as internal walls and partitions.
Figure 3 Floor slab options and floor slab joints
crossbarless frame "Cube-2.5"
Flat floor panels are prefabricated in two modifications: single-module with dimensions 2980x2980x160mm (maximum size 2980x5980x160 mm) and two-module with dimensions 2980x5980x160 mm.
Single-module floor panels are divided depending on their location in the frame (Fig. 3, b) into:
above-column, inter-column, middle (insertion plates).
Two-module panels are formed by combining two adjacent panels: over-column and inter-column; annular and middle (Fig. 3a).
The use of two-module panels is preferable, as this allows you to double the installation time and save on monolithic joints.
When installing the panels, the reinforcing outlets of the ends are combined in such a way that a loop is formed where the reinforcement is inserted and then tied (Fig. 3, c). The seams between the plates are used to pass engineering communications.
The columns are designed in two types: with a section of 400x400 mm with a maximum length of 14600 mm and a section of 200x400 mm with a maximum length of 9200 mm (Fig. 4.5).
At the floor level, the columns have exposed reinforcement (Fig. 4).
Figure 4 Columns of the crossbarless frame "Cube-2.5"
Figure 5 Columns and joints of columns of the Kub-2.5 frameless frame
The joint of the columns provides for forced installation, in which the fixing rod of the lower end of the upper column must enter the branch pipe of the upper end of the lower column (Fig. 5, c). At the same time, the installation of formwork is not required, welding of reinforcement is not provided, construction labor intensity is reduced. Also, the column has vertical risks on all vertical faces for the convenience of geodetic control during the installation of columns (Fig. 5, b).
The junction of the two main elements - the panel and the column was developed using an embedded part - a steel shell (Fig. 5, d), connected to the reinforcing cages located in the body of the panel. Concrete in this node works under conditions of all-round compression, as a result of which it is self-hardening. This made it possible to avoid bath welding at the junction of the columns. There are only mounting seams in the knot.
Installation of structures, which make up the frameless frame as a whole, is carried out in the following order: first, the columns are installed, aligned and embedded in the glasses of the foundations; then, over-column panels are installed at the design level and welded to the reinforcement of the columns; after that, the inter-column and middle panels are mounted “dry” using concrete mounting tables (Fig. 3, d) provided for by the design of the panels; joints between panels are concreted
The practice of using a unified transomless frameless frame of the KUB-2.5 system showed its advantages over other systems:
To date, this is practically the only system that really gives complete freedom. planning solutions(Fig. 6). With its help, you can build buildings with a height of 2 to 25 floors, with any floor height.
Compared to traditional technologies for the construction of multi-storey buildings, this technology is economical: a reduced consumption of concrete and steel gives an overall reduction in construction costs by 5-7%, even taking into account the costs of factory technology for manufacturing elements.
The advantage of the system in comparison with monolithic frames is expressed: in a reduced weight of steel in the ceiling (78.9 kg per 1 m3 with a column spacing of 6x6m); in the possibility of using concrete of higher classes (up to B60) in columns, which affects the results of reinforcement and the preservation of typical cross sections of columns 400 x 400 mm.
All elements of the system, in contrast to the technology of a monolithic frame, are manufactured in a factory way, which makes it possible to almost completely eliminate the option of marriage, since all components of the frameless frame structure undergo strict production control at the enterprise.
The next factor in determining the advantages of this building system is the high speed and ease of installation.
During the construction of objects, a team of 5 people assembles up to 300 m 2 of ceilings per shift, assembles the spatial structure at a rate of 200 m 2, regardless of the time of year and weather conditions. With a good skill of installers, the frame of one section of a 16-storey building can be completed in three months with the installation of all reinforced concrete elements.
By increasing the frame construction speed and saving basic materials, the overall economic efficiency is achieved up to 20% of the total cost for the construction of the above-ground part, which is confirmed by the calculations and practice of using the system in 27 regions of Russia.
Figure 2.5 An example of a residential 16-storey building in the Kub-2.5 frameless frame system
"KUB-2.5" makes it possible to produce prefabricated elements of any used number of storeys in the same types of molds.
For the implementation of residential development (residential and public buildings), it is necessary to have 4 types of forms: column, above-column slab, inter-column slab, middle slab. Stairs, ventilation blocks, elevator shafts can be used in any other structural system mastered by factories producing reinforced concrete products.
These ceilings were a frame system in two directions: with pillars fixed in the foundations and crossbars - cut plates. The most difficult knot - the junction of the slab to the column - was solved by welding the embedded box-shaped part of the slab to the longitudinal working reinforcement of the column. This reinforced concrete frame of buildings was called "unified frame, without crossbars" (KUB-1). Subsequently, modifications of the frame of the "KUB" system were developed for various operational loads and manufacturing conditions.
The next major step in the development of KUB systems was the development of the KUB-2.5 prefabricated monolithic structural system, a set of documentation for which was developed in 1990. In the new modification, the main design solutions of the system have been improved - joints of uncut multi-tiered columns, joints of floor panels, nodes for connecting floor panels with columns that form frame nodes, solution of ties, measures have been introduced to reduce labor costs for the manufacture and installation of elements and optimize economic characteristics. The prefabricated frame is mounted from prefabricated products with subsequent embedding of nodes and joints; at the operational stage, the structure is monolithic.
The KUB-2.5 system provides for the use of enlarged floor panels with maximum dimensions of 2960x5980x160 mm, along with single-module panels with maximum dimensions of 2980x2980x160 mm. If the contractor has the lifting and transport capabilities, it is preferable to use an enlarged version of the floor slabs.
The new design of the attachment points of the ties to the columns reduces the likelihood of frame resonance during forced vibrations (seismic activity, wind loads, etc.). KUB-2.5 system can be used for the construction of residential, public and some industrial buildings, along with the usual construction conditions, also in areas with seismic activity up to 9 points inclusive on the MSK-64 scale.
The frame supporting structure, consisting of 2 main bearing elements of the system, providing its strength qualities - columns and floor slabs, allows the use of local non-constructive materials for building envelopes, including monolithic walls.
Installation of structures is carried out in the following order: columns are mounted and embedded in the foundation glasses, then over-column panels (NP) are installed and welded to the reinforcement of the columns; then intercolumn (MP) and middle panels (SP) are mounted.
The joint of columns provides for forced installation, in which the fixing rod of the lower end of the upper column must enter the branch pipe of the upper end of the lower column. Welding of reinforcement is carried out under the condition of tensile forces at the joint.
Installation of above-column panels on the column is carried out with the help of a mounting conductor, the special bolts of which are previously set to the design mark of the bottom of the panel, the level of the installed panel, if necessary, is adjusted by the same bolts. , using steel mediators in the form of corners or plates. Installation of the floor panels "dry" in the design position is carried out using concrete mounting tables provided for by the design of the panels, while the reinforcing outlets of the ends of adjacent panels are combined in such a way that a loop is formed. Reinforcement is passed into the loop and welded. Next, the joints are monolithic.
Racks are removed only after the overlap of the next (with a similar installation of racks) floor is mounted, monolithic and the concrete of the monolithing has gained at least 70% of the design strength.
The structural system of the crossbarless prefabricated reinforced concrete frame KUB-2.5 makes it possible, in a variety of climatic conditions, to almost completely provide for the construction of the entire range of urban structures: housing, administrative, social, cultural and domestic buildings, multi-storey garages, warehouses, some industrial structures (with spans up to 12 m).
All reinforced concrete structures of the system make it possible to design (build) buildings up to the I degree of fire resistance, which ensures its use for buildings of various heights: cottages, low-rise and high-rise (up to 75 meters) houses.
The minimum number of vertical frame elements and the absence of crossbars allows you to create free layouts of premises for various purposes within the boundaries of the supporting and enclosing structures. Partitions can be located anywhere in the architectural plan, both during the design and construction, and during the operation of the building. The system provides the possibility of redevelopment of premises in accordance with any current needs during the operation of the building without violating the structural stability of the building (gives freedom in organizing offices, shops, sports and recreational and residential complexes on the ground floors in residential buildings).
The load-bearing frame of the building consists only of internal elements (columns, ceilings and, if necessary, connections or diaphragms). Almost any facade solutions can be used as external enclosing structures (walls): lightweight heat-efficient stone (including brick-lined), various hinged panels, ventilated facades, stained-glass fences, etc.
The KUB system allows you to cantilever the floor slabs beyond the axes of the outer columns (up to 1.5 m) and give the slabs along their outer edge almost any shape in plan. The system contains unlimited possibilities for enriching the plasticity of facades, which can satisfy any, the most sophisticated tastes, and are limited only by the imagination of the architect, the customer's requests and the requirements of standards.
Design features of the system
To date, the structural system of the crossbarless frame "KUB-2.5" on the Russian market is the only one in which the frameless frame is fully assembled.
The frame of a building (structure) in the system of a structural frameless frame is a spatial structure, such as a "shelf" of prefabricated, prefabricated-monolithic or monolithic execution. Columns serve as frame racks, floor slabs perform the role of crossbars, ties or diaphragms are used for stiffening elements. Ladders, ventilation blocks, elevator shafts can be used any mastered by manufacturing plants. The bearing capacity of the floors allows the use of the frame in buildings with load intensity per floor of not more than 1300 kg / m 2 (modification KUB-2.5K up to 2500 kg / m 2).
The KUB-2.5 structural system is based on an original junction of two main elements - a panel and a column using an embedded part - a steel shell of a special design connected to reinforcing cages located in the body of the panel. Concrete in this node works under conditions of all-round compression, as a result of which it is self-hardening. This made it possible to avoid bathtub welding at the junction of columns; only assembly seams are present in the node.
The joints of the elements that make up the frameless frame as a whole are monolithic, forming a frame structural system, the crossbars of which are the ceilings.
The division of the floor is designed in such a way that the panel joints are located in areas where the value of bending moments is equal to zero.
An important advantage of the system is the possibility of using concrete of higher classes (up to B60) in columns, which affects the results of reinforcement and preservation of typical cross sections of columns 400 × 400. Columns manufactured at the construction site (in monolithic housing construction) can have a concrete class of up to B30, and this imposes appropriate restrictions on the design of the columns.
External walls are not load-bearing, they do not need foundations, they do not need to be designed as strong as is done in frameless buildings. The load on the frame base is 25% lower than in a monolithic version. Regardless of the soil conditions, the volume of foundations required to distribute the forces on the base from the above-ground part of the buildings made in the structures of the KUB-2.5 system will always be minimal, because the self-weight of the frame is also minimal due to the achieved optimization of all sections.
Crossbarless frame structures are designed for use in various regions of Russia, including areas with seismicity of 7-9 points.
The strength of the KUB-2.5 frame structures is confirmed by technical calculations and numerous tests:
- The designs of the KUB were considered by the STC of the State Committee for Architecture under the Gosstroy of the USSR and recommended for use by letter No. IP-7-3691 dated September 19, 1986;
- TsNIISK them. Kucherenko of the State Construction Committee of the USSR, the frame of the KUB is recommended for use (conclusion of 15.03.1990);
- Laboratory of dynamic tests of TsNIIEP dwellings under the direction of Ashkinadze G.N.
In recent years, more than a thousand objects have been built in Russia and abroad using the KUB-2.5 frameless frame.
Features of construction in the system
The universal structural system "KUB-2.5" is highly industrialized, which is expressed in a high degree of factory readiness of its constituent elements. All elements are produced at the factories of reinforced concrete products.
At the construction site, only the installation of finished elements by mechanized means is carried out, thereby ensuring high rates of construction.
The factory technology for manufacturing building elements used in the system allows the maximum transfer of labor costs of builders to workshop conditions, thereby significantly reducing the risks of both natural and human factors at the construction site.
When developing the frame of the KUB system, solutions were applied that significantly reduce the construction process of erecting the frame of the building:
- installation of vertical structures is carried out immediately on several floors;
- the design of the column joint does not require bath welding of the supporting reinforcement;
- there is no need to install (and subsequent multiple reinstallation) formwork;
- structures of joints of columns and floor panels between themselves do not require the installation of special formwork for embedding the joint, which reduces construction labor intensity;
- products of KUB-2.5 boards are stored in stacks of up to 10 pieces, which allows you to work successfully in a cramped construction site.
In addition, the installation of the frame can be carried out in any weather, and a small number of workers on the construction site reduces the likelihood of using unskilled labor.
Economic justification
Reinforced concrete structures of the KUB-2.5 system are not only rational, but also optimal due to the solutions incorporated in them. Rationality is expressed in reasonably justified, well-thought-out design solutions that provide for a minimum number of building materials(steel and concrete) and labor costs.
Saving materials:
- the consumption of reinforced concrete in the frame (floor panels, columns, monolithic seams) is: 0.179 m³ per 1 m² of floor area;
- steel consumption in reinforced concrete frame elements, incl. reinforcing and rolling, is: 14.3 kg per 1 m² of floor area.
Labor saving:
- construction labor costs - 0.51 people. hour per 1 m² of floor area;
- factory labor costs - 1.92 people. hour per 1 m² of floor area.
The universal structural system of the KUB-2.5 prefabricated monolithic frameless frame is designed on the basis of developed and proven methods, which significantly reduces the time required to complete the work.
The manufacture and construction of the frame is carried out on the basis of a time-tested effective organization of construction production.
The mechanization of labor at all levels of manufacturing precast concrete products and mounting the frame reaches 90%.
All-weather, versatility and flow of frame erection, as well as preliminary design studies, allow you to accurately plan the construction time.
Precast concrete does not require electrical heating, which saves energy costs.
The speed of erection reduces the operating time of tower cranes, and hence the rent for their operation.
The use of a prefabricated reinforced concrete frame of the KUB-2.5 system really reduces the construction time and reduces its cost.
The use of the KUB-2.5 prefabricated system in construction saves up to 28% of the total cost, which increases the profitability of the facility by about 60%.
Frame Unified Transomless "CUBE" is a building system, the main difference of which is the use of industrially manufactured elements of the building frame and their installation on the construction site. Developed by TsNIIEP dwellings back in Soviet times and improved by the authors of the development, who registered the invention at NPO KUB, the prefabricated frame system is designed for the construction of buildings up to 25 floors high in 4 climatic zones with seismic resistance up to 9 points inclusive.
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| Wall panel in the ground (for water separation) |
By analyzing building systems in terms of cost, planning possibilities, labor costs, construction speed, architectural solutions experts agree that in the next 5-7 years, the industrial prefabricated frame will confidently occupy 35-40% of the construction technology market, displacing the large-panel and frame-monolithic schemes from the leading positions, not to mention the construction of small-piece materials. The arguments are pretty obvious:
firstly, frame structures are more versatile - they can be used in all types of construction production - in the construction of residential and office buildings, industrial facilities, shopping and parking complexes;
secondly, the advantage of modern frame technologies in that they give much greater freedom in the choice of architectural solutions;
thirdly, the cost-effectiveness of the prefabricated frame, in comparison with traditional schemes, is 22-28% of the total cost;
and, of course, the main indicator is the reduction of construction time, which allows the customer to quickly return the investment with a profit, and the consumer to celebrate housewarming much earlier.
What is a prefabricated frameless frame?
Products of CS "KUB-2.5" have a simple geometric shape and a minimum number of basic sizes (4).
The frame consists of square columns 400x400 mm and flat floor panels 3x3m, 160 mm thick.
Depending on the location in the plan, floor panels are divided into above-column, inter-column and middle.
The partitioning of the floor is designed in such a way that the panel joints are located in zones where the value of bending moments is equal to zero. The spatial rigidity of the structure is ensured by the monolithic connection of the elements (floors and columns) and, if necessary, by the inclusion of connections and diaphragms in the system.
Installation of structures is carried out in the following order:
Columns are mounted and monolithic in the glasses of the foundations;
Over-the-column panels are installed and welded to the reinforcement of the columns;
Intercolumn and middle panels are mounted.
After installing the clamps, the seams between the panels are monolithic. At the same time, the joints of the above-column slabs with columns are monolithic along the entire floor at this level.
The design of the joints of the columns provides for forced installation, in which the fixing rod of the upper column must enter the branch pipe of the lower column.
There are only mounting seams in the knot.
Structural building system "KUB-2.5" reviewed and recommended for use
The prefabricated frameless frame system has proven itself in more than 30 regions of Russia. The number of its supporters and the volume of development are growing every year.
The KUB-2.5 construction system is designed for the construction of residential buildings, administrative, public and social facilities, residential buildings, multi-storey garages, industrial facilities in various climatic and seismic conditions and is universal.
KUB-2.5 is one of the few building systems in Russia in which the crossbarless frame is fully assembled. Thus, the KUB-2.5 system has architectural, planning and design advantages over traditional beam systems. Its main feature is the absence of crossbars, the role of which is played by floor slabs, and the use of multi-tiered columns without protruding parts (as a result of which the aesthetics of the premises are not violated, material and interior space are saved).
The girderless frame consists of square columns, flat floor panels and, if necessary, ties or diaphragms. The cross section of the columns is 400x400 mm, they can be either single-storey or multi-storey. The developed frame structures provide for the height of floors in buildings of 2.8, 3.0, 3.3 and 3.6 m with the main grid of columns 6x6 m. When strengthening the columns, the floor height can be increased to 11 m. Floor panels have dimensions of 2.98x2 98 m, thus, the gap between them is only 20 mm, which makes it possible to embed the joints without installing formwork. The thickness of the panels is 160 mm. Floor panels, depending on the location, are divided into above-column, inter-column and middle. The bearing capacity of the floors allows the use of the frame in buildings with load intensity per floor up to 1300 kg / m 2.
The KUB-2.5 structural system is based on an original junction of two main elements - a panel and a column using a mortgage made - a steel shell of a special design connected to reinforcing cages located in the body of the panel. Concrete in this node works under conditions of all-round compression, as a result of which its self-hardening occurs. This made it possible to avoid bathtub welding at the junction of columns; only assembly seams are present in the node.
The division of the floor is designed in such a way that the panel joints are located in areas where the value of bending moments is equal to zero. The joints of the elements that make up the frameless frame as a whole are monolithic, forming a frame structural system, the crossbars of which are the ceilings.
Stairs, ventilation blocks, elevator shafts can be used as standard. Almost any facade solutions can be used as external enclosing structures (walls): lightweight heat-efficient stone (including brick-lined), various hinged panels, ventilated facades, stained-glass fences, etc.
Installation of structures is carried out in the following order:
- Columns are mounted and monolithic in the glasses of the foundations;
- Over-the-column panels are installed and welded to the reinforcement of the columns;
- Intercolumn and middle panels are mounted. After installing the clamps, the seams between the panels are monolithic. At the same time, the joints of the above-column slabs with columns are monolithic along the entire floor at this level. The design of the joints of the columns provides for forced installation, in which the fixing rod of the upper column must enter the branch pipe of the lower column. There are only mounting seams in the knot.
The main advantages of the KUB-2.5 system:
Versatility of application and complexity of the frame
- The completeness of the frame means the absence of costly and difficult-to-control monolithic works on the construction site.
- Due to the lack of crossbars and bearing walls there is a possibility of free layouts of premises.
- The frame can be used for the construction of both residential and non-residential buildings.
- With the use of the same type of elements, it is possible to erect buildings up to 25 floors with various architectural and planning solutions.
- Enclosing structures and internal walls can be made from any (including non-structural) building materials.
Reliability and seismic resistance of the frame
- Due to the prefabrication of structures, it becomes possible to use concrete of higher classes (up to B60) in columns, which affects the results of reinforcement and the preservation of typical cross-sections of columns 400 * 400, while columns manufactured at the construction site (in monolithic housing construction) cannot have a comparable class of concrete, which imposes appropriate restrictions.
- The KUB 2.5 system has been worked out from a design point of view.
- All structures are manufactured in the factory, only the installation of finished frame elements is carried out at the construction site. This allows you to transfer labor costs to the conditions of the precast concrete plant as much as possible, thereby reducing the risks of natural and human factors. Factory production control guarantees the quality and reliability of designs.
- Frame structures are designed for use in various regions of Russia, including areas with seismicity of 7-9 points
- The system uses a new design of attachment points for ties to columns, which reduces the likelihood of resonance of structures during forced vibrations.
Economic efficiency of construction
- Low material consumption of the frame, the consumption of concrete and steel per 1 m2 of the structure is much lower compared to other systems.
| Technical and economic indicators per 1 sq.m. floors according to TsNIIPI "Monolith", Moscow | |
| Concrete (precast) | 0.19 m3/m2 |
| Concrete (sealing of seams) | 0.016 m3/m2 |
| Metal | 12.63 kg/m2 |
| Actual Work | 0.51 person/hour per m2 |
- Economic efficiency due to low labor costs for installation and high speed of frame erection.
- Savings on energy resources and the use of fixed assets. Precast concrete does not require electrical heating, which saves energy costs, due to the speed of erection of the frame, the operation time of tower cranes is reduced.
- Low consumption of reinforced concrete per 1 m2 of frame overlap.
- Savings on the arrangement of the foundation. The load on the foundation of a building built using the KUB-2.5 frame is 25% less than from a similar one in a monolithic design. The self-weight of the frame is minimal due to the achieved optimization of all sections. Regardless of the soil conditions, the volume of foundations required to distribute the forces on the foundation from the above-ground part of the buildings made in the KUB-2.5 structures will always be lower.
| Indicators | Unit rev. | Known Solutions | ||||
| efficiency, series | KUB-2.5 system | Monolithic | Bricks | |||
| 90 | 111 | |||||
| Reinforced concrete consumption | M 3 | 0,85 | 0,80 | 0,17 | 0,20 | 0,14 |
| Incl. monolithic | M 3 | 0,02 | 0,02 | 0,12 | 0,20 | 0,02 |
| Steel consumption for supporting structures | kg | 14,5 | 14,2 | 12,3 | 19,7 | 12,0 |
| Consumption of materials for enclosing structures (brick, cellular concrete stones) | M 3 | 0,02 | 0,02 | 0,30 | 0,30 | 0,85 |
| Ensuring free planning solutions | ||||||
| Construction cost | % | 100 | 100 | 87 | 92 | 100 |
Possibility of applying various architectural solutions
- The framework of the KUB-2.5 system makes it possible to realize the widest range of architectural solutions for the facade of the building, which can satisfy any taste, and are limited only by the imagination of the architect, the requests and wishes of the Customer, and the requirements of Building Regulations.
- The KUB-2.5 system allows you to cantilever the floor slabs beyond the axes of the outermost columns (up to 1.5 m) and give the slabs almost any shape along their outer edge, up to radial displacement on any floor, not to mention the installation of bay windows, loggias and balconies.
- The KUB-2.5 frame allows the use of different facade systems. Almost any facade solutions can be used as external enclosing structures: lightweight heat-efficient stone (including brick-lined), various hinged panels, ventilated facades, stained-glass fences, etc.
Efficient Design Capabilities
- Free layout and redevelopment of premises due to the absence of load-bearing walls and crossbars, including in an already operated building.
- With a main column spacing of 6x6m, the system gives more freedom for design than other types of frames that use a smaller multiplicity.
- The ability to vary the distance between the floors, and, consequently, the height of the premises at the request of the customer from 2.8 to 3.6 m.
- The KUB-2.5 system allows solving various urban planning tasks; it is possible to use the system in a complex urban planning situation under cramped construction conditions and with compaction of urban development in the existing quarters.
High speed and ease of frame construction
- Assembly of the frame according to the principle of "designer", execution of elements according to factory standards.
- Installation of vertical structures is carried out immediately on several floors. The design of the column joint does not require bath welding of the working reinforcement.
- There is no need for installation (and subsequent repeated reinstallation) of the formwork.
- A small number of installers is required at the construction site, which reduces the risks of the human factor and the likelihood of using unskilled labor (an experienced team of 5 people installs up to 300 m2 of flooring per shift).
- Installation of the frame can be carried out in any weather conditions, which extends the seasonal construction period.
- Ability to transport the structures of the KUB 2.5 system by rail, road or water transport, including other cities.
The strength of the frame structures "KUB-2.5" is confirmed by technical calculations and numerous tests:
- The designs of the KUB were reviewed by the NTS of the State Committee for Architecture under the USSR State Construction Committee and by letter No. IP-7-3691 dated 19.09.1986 and recommended for use;
- TsNIISK named after Kucherenko of the State Construction Committee of the USSR;
- Laboratory of dynamic tests of TsNIIEP dwellings under the direction of Ashkinadze G.N. (successfully passed dynamic tests).
