Receptions of constructive decisions of buildings. Structures of a transom frame How to determine a transom or transom frame

One of the modifications frameless frame is a prefabricated monolithic frame or frame-braced frame with flat floor slabs, including multi-storey columns with a maximum length of 13 m of square section 40x40 cm, above-column, inter-column floor panels and insert panels of the same size in terms of 2.8x2.8 m and a single thickness of 160 and 200 mm, as well as diaphragm stiffness.

frame designed for the construction of relatively simple buildings in terms of composition, up to 9 floors high with a frame scheme and 16 ... 20 floors with a frame-braced scheme with cells in a 6x6 plan; 6x3 m, and with the introduction of metal sprengels on cells 6x9; 6x12 m at a height of 3.0; 3.6 and 4.2 m with full vertical load up to 200 kPa and horizontal seismic load up to 9 points.

The foundations are monolithic and prefabricated glass type. External enclosing structures are self-supporting and hinged from various materials or standard industrial products of other structural systems. Stairs are mainly made of stacked steps on steel stringers. The joints of the frame elements are monolithic, forming a frame system, the crossbars of which are the ceilings.

Installation of structures is carried out in the following order: they are mounted and embedded in the glasses of the column; mount over-column panels with high accuracy, on which the quality of installation of the entire ceiling depends; intercolumn panels are installed on the above-column panels. Then the insert panels are mounted. After alignment, straightening and fixing of the floor, reinforcement is installed in the seams of monolithic and the seams between the panels and joints of panels with columns throughout the floor are installed.

frame calculated on the action of vertical and horizontal loads by the method of replacing frames in two directions. In this case, a slab with a width equal to the pitch of the columns of the perpendicular direction is taken as the crossbar of the frame.

When calculating the system for the action of horizontal forces in both directions, the full design load is taken, the bending moments from which are introduced in full value into the design combinations. When calculating the system for the action of vertical forces, the work of the frame is taken into account in two stages: installation and operational. At the installation stage, hinged support of floor panels is taken in places of special mounting devices, except for above-column panels, which are rigidly connected to the column. In the operational stage, the frames are calculated for the full vertical load in two directions. The design bending moments are distributed in a certain ratio between the spans and the overstring strips.

Force effects on the columns at the bottom level of the floor panel are determined by formulas that take into account the two-stage operation of the structure. Elements of the structural system are prepared from concrete of class B25 and reinforced with steel reinforcement of classes A-I; A-II and A-III.

A characteristic feature of the system is the junction of the above-column panel with the column. To effectively transfer the load from the panels to the column, the column is trimmed along the perimeter at the level of the floor with four bare corner rods exposed. The collar of the above-column panel in the form of angle steel is connected to the rods with the help of mounting parts and welding.

The node for connecting floor panels of the Perederiya joint type, in which longitudinal reinforcement 0 12-A-P is passed and embedded in bracket-shaped reinforcement outlets. For efficient transfer of vertical load in the panels, longitudinal triangular grooves are provided, which form with the concrete of the monolithic seam (200 mm wide) a kind of key that works well for shearing.

The specified constructive system is designed for use in areas with an underdeveloped precast concrete industry for buildings for various purposes with relatively low requirements for the indicator of industriality (degree of factory readiness) of the system. Principal solutions of a prefabricated monolithic frame without crossbars.

The technical and economic indicators of the system are characterized by a somewhat lower consumption of metal than frame-panel systems for the same cell parameters, but by a higher consumption of concrete and significant construction labor intensity.

The owners of the patent RU 2588229:

SUBSTANCE: invention relates to the field of construction, namely to reinforced concrete multi-storey frames without crossbars for the construction of residential, industrial and civil buildings, both for normal construction conditions and for construction in seismic areas.

From the prior art, a contact joint of precast concrete columns is known with a break in the rods of longitudinal working reinforcement in the joint, with the butts of the columns supported by a layer of high-strength mortar, while steel plates are installed on the supporting ends of the columns, installation of short reinforcing bars through the joint in channels filled with high-strength with a solution, it is provided for edging the end in the form of a steel ledge, as well as the installation of steel liners in the center and along the contour of the joint in the gap between the steel end plates equal to the size of the gap. (1) (see RF patent N 2233368, MCP E04B 1/38, 2004).

The disadvantage of this technical solution is the high complexity of making this joint, in addition, the use of differently deformable materials in the contact zone of columns will lead to stress concentration in areas of less deformable materials and, as a result, local (local) cracking, as well as through passage of short rods in additional channels violates the integrity of the reinforced concrete section of the columns and, as a result, a decrease in the bearing capacity of the butt joint.

It is also known a technical solution for the arrangement of contact joints of prefabricated reinforced concrete columns with a break in the working reinforcement, with the ends of the columns resting on a thin layer of mortar without connecting the reinforcement (2) (see A.P. Vasiliev, N.G. Matkov, M.F. Zhanseitov ., Contact joints of columns with a break in the longitudinal reinforcement., Concrete and reinforced concrete N 8, 1982)

This well-known technical solution and its experimental study allows us to conclude that it is advisable to use it for multi-storey building frames. The disadvantage of this butt joint is that it is unsuitable for tensile forces.

Known arrangement of joints of reinforced concrete columns with reinforcement of the end joined sections of reinforced concrete columns with metal elements. (3) (V.S. Plevkov, M.E. Goncharov, Study of the work of joints of reinforced concrete columns reinforced with metal elements under static and short-term dynamic loading, Vestnik TSSU N 2, 2013)

This study of the zone of joints of reinforced concrete columns shows that the bearing capacity of the joint using metal clips in the zone of joined columns increases by 30-40%.

A technical solution is known for the connection of a prefabricated reinforced concrete column and a prefabricated over-the-column floor slab of a transom-free, capital-free frame of a building, in which the connection is carried out using trapezoidal connecting plates welded on one side to the power reinforcement of the columns exposed in the overlap zone, on the other hand, to the monolithic in the over-column floor slab steel shell. (4) (see RF patent N 2203369, MCP E04B 1/38, 2003)

The disadvantage of this technical solution is the laboriousness and material consumption for the installation of the shell in the above-column slab, in addition, this connection, until the joint is monolithic, has insufficient rigidity due to the high flexibility of the exposed power reinforcement of the columns. It should be attributed to the disadvantages of this technical solution the fact that trapezoidal connecting elements are welded to the exposed power reinforcement of the columns for fastening the above-column plates and at the same level the connecting elements of the longitudinal power reinforcement of the columns are welded. This circumstance leads to a decrease in the quality of welded joints. The negative qualities of this technical solution also include the floor-by-floor adjustment of the position of the outlets of the power reinforcement of the columns when changing its floor-by-floor diameter.

It is known to connect a slab of a beamless prefabricated monolithic floor with a prefabricated column, where the column in the support zone of the slab has a recess along the perimeter of the column (5) (USSR patent N 872674, MKI E04B 1/20, 1981)

The disadvantage of this technical solution is the insufficient bearing capacity of this joint for punching in a flat overlap.

A technical solution is known for the butt joint of a monolithic beamless reinforced concrete floor with a monolithic column in which steel plates are rigidly fixed to the vertical reinforcement cages of the floor in the joint area, the plates are made with a length of at least 2h + 2a, where h is the thickness of the slab, a is the thickness of the concrete protective layer. (6) (see RF patent N 2194825, MCP E04 B 5/43.2002).

This technical solution increases the bearing capacity of the butt joint by shear force.

The closest technical solution adopted for the prototype is the design of a transomless reinforced concrete frame, which includes one or more storey non-cantilever prefabricated columns with exposed power reinforcement at the intersection with the floor, prefabricated over-column floor slabs with through holes framed by a steel shell for the passage of multi-storey columns and butt connection with them, prefabricated span slabs, monolithic sections combined with each other into a single floor disk, while the installation of span slabs is carried out by protruding consoles on the corresponding support tables, over-column and span slabs have loop outlets on the end ribs through the overlap of which reinforcing bars are passed with subsequent concreting of the joint cavity. (7) (see RF patent N 2247812, MCP E04B 5/43, 2005)

The technical solution of inter-slab joints in this design of a frameless frame is hinged, which limits the span of a prefabricated monolithic floor. In addition, this design of the prefabricated-monolithic floor is rigid for the options for solving space-planning tasks, and also for this technical solution, the shortcomings set forth in the analogue (4) are valid.

The objective of the invention of a prefabricated-monolithic frameless frame is to increase the range of solving space-planning problems, increase the bearing capacity of frame structures and its nodal connections, and increase the manufacturability of work on the construction of frame structures.

This invention of a prefabricated monolithic reinforced concrete frame without crossbars is a series of technical solutions with options for the execution of prefabricated frame elements and their possible layout in combination with monolithic sections, depending on planning, technological factors, as well as the industrial base for the production of prefabricated reinforced concrete products.

Variants of technical solutions for a prefabricated monolithic reinforced concrete frame without crossbars with hinged monolithic inter-slab joints, with rigid (continuous) monolithic inter-slab joints, as well as options for a free combination of prefabricated reinforced concrete elements with span monolithic sections of the floor, interconnected in a continuous disk of floor, are presented.

The drawings show:

in fig. 1 - a schematic fragment of the plan of a prefabricated monolithic frameless frame with configuration options for prefabricated frame elements and their possible layout in combination with monolithic sections;

in fig. 2 - an enlarged fragment of the 1st floor plan of a reinforced concrete frame without crossbars with hinged monolithic inter-slab seams between prefabricated above-column and span slabs;

in fig. 3 - an enlarged fragment of the second floor plan of a reinforced concrete frame without crossbars with rigid (continuous) monolithic inter-slab seams between prefabricated floor slabs;

in fig. 4 - an enlarged fragment of the III floor plan of a reinforced concrete frame without crossbars with rigid (continuous) monolithic inter-slab seams between prefabricated floor slabs and a rigid (continuous) connection of prefabricated slabs with monolithic span sections of the floor;

in fig. 5 - cross section I-I (with diagonal ties);

in fig. 6 - cross section I-I (with monolithic diaphragms);

in fig. 7 - Node 1 (section A1-A1) - butt joint of a multi-storey continuous prefabricated cantilevered column with a prefabricated over-column floor slab;

in fig. 8 - view B1-B1 of node 1 - butt connection of a multi-storey continuous prefabricated cantilevered column with a prefabricated above-column floor slab;

in fig. 9 - Node 2 (section A2-A2) - node of butt connection of prefabricated cantilevered columns between themselves and butt joint of columns with above-column floor slab;

in fig. 10 - view B2-B2 of node 2 - butt connection of prefabricated non-cantilever columns to each other and butt connection of columns with an above-column floor slab;

in fig. 11 - section A4-A4 - section along the butt joint of prefabricated non-cantilever columns between themselves and with a monolithic section of the floor;

Fig 12 - view B3-B3-butt connection of prefabricated cantilevered columns between themselves and with a monolithic section of the floor;

in fig. 13 - Node 2 (section A3-A3) - the node of the butt connection of prefabricated non-cantilever columns to each other and the butt joint of the columns with the above-column floor slab;

in fig. 14 - section A5-A5 - section along the butt joint of prefabricated cantilevered columns between themselves and with a monolithic section of the floor;

in fig. 15 - section A6-A6 at the junction of the mounting support ledge and the mounting support platform for mounting above-column and span slabs for overlapping with hinged inter-slab joints;

in fig. 16 - section A7-A7 on the device of a monolithic slab joint for overlapping with hinged slab joints;

in fig. 17 - section A8-A8 along the assembly fixation of prefabricated floor slabs between themselves for overlapping with rigid (continuous) interslab seams;

in fig. 18 - section A9-A9 on the device of a monolithic inter-slab seam with a rigid (continuous) connection of prefabricated floor slabs;

in fig. 19 - section A10-A10 along a rigid (continuous) junction of prefabricated floor slabs with a monolithic span section of the floor for non-welding connection using U-shaped anchors and U-shaped anchor outlets;

in fig. 20 - section A11-A11 along a rigid (continuous) connection of prefabricated floor slabs with a monolithic span of the floor by welding U-shaped anchors to embedded parts of prefabricated floor slabs;

in fig. 21 - section A12-A12 along a rigid (continuous) joint of prefabricated floor slabs with a monolithic span of the floor by welding U-shaped anchors reinforced with rigid inserts to embedded parts of prefabricated floor slabs;

in fig. 22 - enlarged fragment IV, detailing of a fragment of the ceiling with a balcony section of the slab, as well as the installation of a curtain wall with a facing layer of brick;

in fig. 23 - view B4-B4 - detail of the fastening of the contour support corner for supporting the facing layer of the outer wall of brick;

in fig. 24 - section A13-A13 on the reinforcement of the rib between the holes for placing insulation packs on the balcony sections of prefabricated floor slabs;

in fig. 25 - section A14-A14 for the placement of insulation packages on balcony areas in the body of prefabricated floor slabs;

in fig. 26 - Node 5 (section A15-A15) node for the installation of a floor curtain wall with a facing layer of brick;

in fig. 27 - section A16-A16 - for the installation of a floor-by-story curtain wall of prefabricated three-layer wall panels;

in fig. 28 - Node 6 (section A17-A17) node for the installation of an external fence with a hinged ventilated facade;

in fig. 29 - Knot 3 - the attachment point of the diagonal ties in the upper level between themselves and with the bonded floor slab;

in fig. 30 - view B5-B5 of node 3 - fastening of diagonal braces with a braced floor slab;

in fig. 31 - section A18-A18 along node 4 - fastenings of diagonal braces in the upper level to each other;

in fig. 32 - Knot 4 - the attachment point of the diagonal braces to the column in the lower level;

in fig. 33-section A19-A19 along the attachment point of the diagonal braces to the column in the lower level;

in fig. 34 - Node 7 - node for connecting a monolithic diaphragm with a column;

in fig. 35 - section A20-A20 along the junction of the monolithic diaphragms with the column;

in fig. 36 - section A21-A21 along the interfloor connection of monolithic diaphragms.

Reinforced concrete prefabricated-monolithic frameless frame with hinged monolithic interplate joints includes reinforced concrete one or more storey non-consolidated columns 1, prefabricated over-column floor slabs 2 with holes 3 for passing columns 1 and butt connection with them, prefabricated span slabs 4, monolithic sections in the form of hinged inter-slab seams combined into a single floor disk, while the prefabricated above-column floor slabs 2 and span slabs 4, for mounting assembly, are equipped with mounting support projections 5 and support platforms 6, and embedded parts are installed on the support surfaces of the support projections 5 and support platforms 6, for example, from steel corners 7, to which are welded - shaped stiffeners 8 from vertical steel plates, embedded in the body of prefabricated slabs 2 and 4 and welded to the longitudinal upper and lower rods of the anchoring frames 9. In hinged monolithic interplate seams between prefabricated slabs 2, 4 in the areas between the mounting supports 5, 6, along the joints between the slabs, the installation of the upper and lower horizontal rods 10 is provided at the inner corners of the overlap of the U-shaped loop anchor outlets 11, installed at the ends of the prefabricated slabs 2, 4, followed by concrete pouring with monolithic concrete 12.

Reinforced concrete prefabricated-monolithic frame without crossbars with rigid monolithic inter-slab seams includes prefabricated reinforced concrete one or more storey cantilevered columns 1, prefabricated over-column floor slabs 13 with holes 3 for passing columns 1 and butt connection with them, prefabricated span slabs 14, broadened monolithic inter-slab seams , or monolithic span sections 15 combined into a single continuous floor disk, while mounting fixation of prefabricated floor slabs 13, 14 is carried out using steel plates 16 welded to embedded parts from channel profiles 17 and to vertical loop anchor outlets of trapezoidal shape 18 located on adjacent end surfaces of joined slabs, while the connection of prefabricated slabs 13 and 14, in the areas between the areas of mounting fixation, is carried out along widened monolithic inter-plate seams by installing, along the joint contour, upper and lower horizontal reinforcing bars 10, located at the inner corners of the overlap of the U-shaped loop anchor outlets 19 from the end faces of adjacent prefabricated floor slabs 13 and 14, while the overlap length of the U-shaped loop anchor outlets 19 from the end faces of adjacent floor slabs 13 and 14 must be at least 15d, where d is the diameter of the anchor outlets.

For the version of the prefabricated monolithic reinforced concrete frameless frame with the replacement of one or more span slabs 14 with a monolithic span 15, the connection of prefabricated slabs 13 and 14 with a monolithic span 15 is carried out by installing horizontal upper and lower reinforcing bars 10 along the joint contour at the inner corners of the overlap p-shaped vertical loop anchor outlets 19 from the end surfaces of prefabricated floor slabs 13 and 14 and vertical p-shaped loop anchors 20 installed along the contour of the junction of monolithic span sections 15 with prefabricated floor slabs 13, 14, while the length of the overlap of the vertical p-shaped loop anchor outlets 19 from the end faces of adjacent floor slabs 13 and 14 and vertical U-shaped loop anchors 20 must be at least 15d, where d is the maximum diameter of anchor outlets 19 or anchors 20.

The connection of prefabricated floor slabs 13 and 14 with a monolithic span 15 can also be performed using vertical U-shaped loop anchors 20 or 21 welded to vertical embedded parts from channel profiles 17 located on the end surfaces of prefabricated floor slabs 13, 14, while -shaped loop anchors 21, at the end sections have stiffeners 22 made of steel plates welded along the vertical axis, between the upper and lower rods of the U-shaped loop anchors 21.

The device of balcony sections of the floor is proposed to be performed in two versions:

either the balcony part of the ceiling rests on columns 1 placed outside the outer fence of the building with external above-column balcony slabs 23 and span balcony slabs 24, or the balcony part of the ceiling is integral (continuous) with above-column 2, 13 and span 4, 14 floor slabs, while in plates 2, 4, 13, 14 are provided with holes 25, in the plane of the outer fence, to accommodate insulation packages, while the reinforcement of the ribs between the holes 25 is carried out by vertical reinforcing cages 26, which have stiffeners 27 from steel plates welded in the upper and lower reinforcing bars frames 26.

For a prefabricated monolithic reinforced concrete frame without girder with monolithic hinged or rigid monolithic interplate joints, longitudinal interplate joints are made staggered with an offset in each transverse row of joined prefabricated floor slabs 2, 4, 13, 14 by an amount not less than the anchoring length of the maximum diameter of the working reinforcement of plates 2 , 4, 13, 14.

The device for supporting connection of above-column slabs 2, 13 with prefabricated cantilever columns 1 is carried out as follows: columns 1 are made with vertical embedded parts 28, 29, 30 installed in recess 31 from the outer faces of column 1 along its perimeter within and not less than the thickness of the ceiling, above-column plates 2, 13 are made with vertically arranged trapezoidal outlets 32 of steel plates rigidly connected to the upper and lower rods of the anchor reinforcement cages 33 installed along the perimeter of the through holes 3.

The connection of prefabricated columns 1 and above-column slabs 2, 13 is carried out using steel connecting elements 34, for example, from unequal corners welded to vertical embedded parts 28, 29 of columns 1 and to vertical trapezoidal outlets 32 from above-column floor slabs 2, 13, followed by concreting of the joint cavity between the recessed part 31 of the column 1 and the end surfaces 35 of the through holes 3 of the above-column floor slabs 2, 13, while the end surfaces 35 of the above-column slabs 2, 13 are inclined from the vertical forming a wedge-shaped cavity of a monolithic joint.

When connecting reinforced concrete non-cantilever columns 1 with a monolithic span section of the floor 15, vertical U-shaped loop anchors 21 are installed, welded to the vertical embedded parts 28, 29 of the columns 1, installed in the recess 31 from the outer edges, along the contour of the column 1, while p- shaped loop anchors 21 at the end sections have stiffeners 22 made of steel plates welded along the vertical axis between the upper and lower rods of the loop anchors 21, followed by concreting with a monolithic floor section 15.

Butt joints of non-cantilever reinforced concrete columns 1 of the frame are carried out by resting on each other with flat ends through the mortar joint 36 within the thickness of the interfloor overlap, while the ends of the joined columns 1 are made with indirect reinforcement with reinforcing meshes 37 and internal reinforcing clips 38, in addition, along the perimeter of the ends of the joined columns 1 are provided with vertical embedded parts 29, 30 in the recess 31 from the outer faces of the column 1.

The connection of the joined columns 1 is carried out by welding the V-shaped reinforcing connecting elements 39 along the planes of the vertical embedded parts 29, 30, followed by concreting with monolithic concrete of the floor.

In addition to technical solutions that have significant differences from the technical solutions of analogues and prototypes, in the illustrative example of a precast-monolithic reinforced concrete frameless frame, technical solutions are also used that are not the subject of this invention, but their use in this example of a precast-monolithic reinforced concrete frameless frame is appropriate.

In the exemplary embodiment, the device of diagonal ties 40 is presented, which are recommended to be arranged during the construction of a prefabricated monolithic frame without crossbars under normal construction conditions, also with a seismicity of no more than 7 points.

The connection of the diagonal ties 40 is carried out at the lower level by means of connecting plates 41 welded to the embedded parts of the columns 1 and the diagonal ties 40, at the upper level by welding the intermediate element 42 of the box section to the embedded parts of the braces 40 and to the anchor outlets 18 of trapezoidal shape from the end faces openings of the bonded floor slab 43 with the help of steel plates 44, while the end sections of the anchor outlets 18 are provided with rigid inserts 22 of steel plates between the upper and lower rods of the anchor outlet 18. The cavity of the butt joint of the diagonal ties 40 with the bonded floor slab 43 is concreted with concrete 12.

For construction conditions with a seismicity of 8 or more points, it is recommended to perform monolithic diaphragms of stiffness 45 in a prefabricated monolithic frame without crossbars.

Monolithic stiffness diaphragms contain, in addition to double-sided reinforcement along the field of a monolithic diaphragm, vertical reinforcement 46 and elements of connection with the foundation, columns, floor slabs from rigid inserts 46 and reinforcing anchor cages 48.

The device of a floor mounted external fence is carried out using, for example, a brick facing layer 49, which is laid along the contour corner 50 welded to the embedded parts of the channel section 51 located at the outer end of the intermediate floor, and the contour corner has vertical slots 52 to make a vertical welding flank seam in at the point of joining with embedded parts 51, in addition, along the supporting surface of the contour corner 50, along the outer edge, a horizontal thrust rod 53 is welded to prevent slipping of the facing brickwork 51 from the supporting surface of the contour bearing corner 50. A sealing elastic gasket is laid floor by floor under the contour bearing corner 50 54. On the outside of the brickwork 49, the floor horizontal seam for supporting and sealing the brick facing masonry is closed with a decorative flashing 55.

A variant of the floor mounted external fencing are, for example, prefabricated external wall panels 56 supported floor by floor over a layer of cement-sand mortar on interfloor floors. To fix the outer wall panels 56 in the plane of the facade of the building 57, on the joined ends of the outer wall panels 56, a ledge 58 and a protrusion 59 are provided, which, when docked dry, ensure that the facade surfaces of the joined outer wall panels 56 coincide with the plane of the facade of the building 57. Lower and upper the end surfaces of the joined outer wall panels 56 are separated by sealing elastic gaskets 54. From the outside, the seams between the outer wall panels 56 are closed with a decorative strip 60.

For an external fence using a ventilated facade 61, floor by floor, along the contour of the floor slabs, a building envelope is made of brickwork 62, or from precast concrete partitions, to which the system of structures of the ventilated facade 61 is attached. The external fence of the basement of the building is made using prefabricated vertical wall slabs 63 installed along the outer contour of the ceiling. Wall slabs 63 are supported by a cross-cast reinforced concrete belt 64, which has a perimeter ledge 65 for absorbing horizontal forces from soil pressure.

1. Prefabricated monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-story cantilevered columns, prefabricated over-column floor slabs with through holes for the passage of columns and butt connection with them, prefabricated span slabs, monolithic sections, interconnected into a single floor disk , characterized in that the joined columns rest on each other with flat ends through the mortar joint within the thickness of the ceiling, while the ends of the joined columns are made with indirect reinforcement with reinforcing meshes and internal reinforcing clips, in addition, along the perimeter of the ends of the joined columns, vertical embedded parts are provided in deepening from the outer faces of the column, while the connection of the joined columns is carried out by welding V-shaped reinforcing connecting elements along the planes of vertical embedded parts, followed by concreting the joint with monolithic concrete of the floor.

2. Prefabricated monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-storey cantilevered columns, prefabricated over-column floor slabs with through holes for the passage of columns and butt connection with them, prefabricated span slabs, monolithic sections, combined together into a single floor disk , characterized in that the columns are made with vertical embedded parts installed in the recess from the outer faces of the column along its perimeter within the thickness of the floor, and the above-column floor slabs are made with vertically located trapezoidal outlets made of steel plates rigidly connected to the upper and lower rods of the anchor reinforcement cages, through holes installed along the perimeter, while the connection of prefabricated columns and above-column floor slabs is carried out using supporting steel connecting elements in the form of plates or unequal angles welded to the vertical embedded parts of the columns and to vertical trapezoidal outlets from the above-column floor slabs, followed by concreting of the joint cavity between the recessed part of the columns and the end surfaces of the through holes of the above-column floor slabs, while the end surfaces of the through holes of the above-column floor slabs are inclined from the vertical, forming a wedge-shaped cavity of a monolithic joint.

3. Prefabricated monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-story cantilevered columns, prefabricated above-column floor slabs with through holes for the passage of columns and butt connection with them, prefabricated span slabs, monolithic sections, interconnected into a single floor disk , characterized in that the longitudinal monolithic sections in the form of interslab seams are made staggered with an offset in each transverse row of joined prefabricated floor slabs by an amount not less than the anchoring length of the maximum diameter of the working reinforcement of prefabricated floor slabs.

4. Prefabricated monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-story cantilevered columns, prefabricated over-column floor slabs with through holes for passing columns and butt connection with them, prefabricated span slabs, monolithic sections, combined together into a single floor disk , characterized in that the prefabricated above-column and prefabricated span slabs are equipped with mounting support projections and support platforms, and on the support surfaces of the support projections and support platforms, embedded parts made of steel plates or corners are installed, to which are welded - shaped stiffeners from vertical plates embedded in the body of prefabricated floor slabs and vertical anchoring frames welded to the longitudinal upper and lower rods.

5. Prefabricated monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-story cantilevered columns, prefabricated over-column floor slabs with through holes for the passage of columns and butt connection with them, prefabricated span slabs, monolithic sections, combined together into a single floor disk , characterized in that the mounting fixation of prefabricated floor slabs between themselves is carried out using steel plates welded to embedded parts from channel profiles and to vertical loop anchor outlets of a trapezoidal shape located on adjacent end surfaces of the joined slabs, while the connection of prefabricated slabs in the areas between sections of mounting fixation is carried out by installing along the joint contour of the upper and lower horizontal reinforcing bars located at the inner corners of the overlap of the u-shaped loop anchor outlets from the end faces of adjacent prefabricated floor slabs, while the length of the overlap of the u-shaped loop anchor outlets from the end faces of adjacent slabs overlap should be at least 15d, where d is the diameter of the anchor outlets, followed by concreting of the cavity between the slabs.

6. A prefabricated monolithic reinforced concrete frame without crossbars according to claim 5, characterized in that the vertical loop anchor outlets of a trapezoidal shape, located on the end surfaces of the joined plates at the end sections, have stiffeners made of steel plates welded along the vertical axis of the anchor outlets to their upper and bottom rods.

7. Prefabricated monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-story cantilevered columns, prefabricated over-column floor slabs with through holes for passing columns and butt connection with them, prefabricated span slabs, monolithic sections, combined together into a single floor disk , characterized in that the connection of prefabricated over-column and prefabricated span slabs with monolithic span sections of the floor is carried out by installing horizontal upper and lower reinforcing bars along the joint contour, located at the inner corners of the overlap of U-shaped loop anchor outlets from the end faces of prefabricated floor slabs and vertical u-shaped loop anchors installed along the contour of the junction of monolithic span sections of the floor with prefabricated floor slabs, while the length of the overlap of the n-shaped loop anchor outlets from the ends of the prefabricated floor slabs and p-shaped loop anchors installed along the contour of the junction of monolithic span sections with prefabricated floor slabs should be at least 15d, where d is the diameter of the anchors and anchor outlets.

8. Prefabricated monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-story cantilevered columns, prefabricated over-column floor slabs with through holes for the passage of columns and butt connection with them, prefabricated span slabs, monolithic sections, combined together into a single floor disk , characterized in that the connection of prefabricated floor slabs with monolithic span sections of the floor is carried out using vertical U-shaped loop anchors welded to vertical embedded parts from channel profiles located on the end surfaces of prefabricated floor slabs, while U-shaped loop anchors on the end sections have stiffening ribs made of steel plates welded along the vertical axis of loop anchors between their upper and lower rods, followed by concreting of the connection with a monolithic span section of the floor.

9. Prefabricated monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-story cantilevered columns, prefabricated over-column floor slabs with through holes for the passage of columns and butt connection with them, prefabricated span slabs, monolithic sections, combined with each other into a single floor disk , characterized in that on the balcony sections of over-column or span slabs that have holes in the plane of the outer walls for the placement of insulation packages, the reinforcement of the ribs between the holes for the placement of insulation packages is carried out by vertical reinforcing cages that have stiffeners made of steel plates welded to top and bottom reinforcing bars of vertical frames.

10. Prefabricated-monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-story consoleless columns, monolithic ceiling, characterized in that the columns are made with vertical embedded parts installed in the recess from the outer faces of the column along its perimeter within the thickness of the ceiling, while the connection of prefabricated columns with a monolithic ceiling is carried out using vertical u-shaped loop anchors welded to the vertical embedded parts of the columns, and the u-shaped loop anchors at the end sections have stiffeners made of steel plates welded along the vertical axis of the loop anchors between their upper and lower rods, followed by concreting of the joint with concrete of a monolithic floor.

The invention relates to the field of construction, in particular to a prefabricated monolithic reinforced concrete frame without crossbars. The frame is formed by prefabricated cantilevered columns, prefabricated over-column floor slabs with through holes for passing columns, span slabs and monolithic sections. Options for connecting columns and floor slabs are proposed. The technical result of the invention is to increase the bearing capacity of the frame structures and its nodal connections. 9 n. and 1 z.p. f-ly, 36 ill

One of the modifications of the beamless frame is a prefabricated monolithic frame or frame-braced frame with flat floor slabs, including multi-storey columns with a maximum length of 13 m of square section 40x40 cm, above-column, inter-column floor panels and insert panels of the same size in terms of 2.8x2.8 m and a single thickness of 160 and 200 mm, as well as stiffening diaphragms.

The frame is designed for the construction of relatively simple buildings in terms of composition, up to 9 floors high with a frame scheme and 16.20 floors with a frame-braced scheme with cells in a 6x6 plan; 6x3 m, and with the introduction of metal sprengels on cells 6x9; 6x12 m at a height of 3.0; 3.6 and 4.2 m with full vertical load up to 200 kPa and horizontal seismic load up to 9 points.

The frame is calculated for the action of vertical and horizontal loads by the method of replacing frames in two directions. In this case, a slab with a width equal to the pitch of the columns of the perpendicular direction is taken as the crossbar of the frame.

arbuild.com

Frameless frame structures

KBK is a universal system used for the construction of almost the entire range of urban structures: residential, socio-cultural, administrative and household buildings, multi-level parking lots, warehouses, and some industrial buildings. A domestic development was chosen as the basis for the CSC - the KUB-2.5 frameless frame system. It has been used in our military construction complex for many years, has been worked out from a design point of view and adapted to the existing Russian technological culture in the construction industry. A modification of the KUB system under the abbreviation USMBK was used in the construction of objects of the Ministry of Defense in various countries.

In terms of construction time frameless systems can only compete with buildings erected from reinforced concrete panels. But the quality of panel housing does not meet modern requirements. In particular, many buyers are not satisfied with the impossibility of redevelopment and the inevitable uniformity of the buildings under construction.

The advantage of the KBK frameless frame, first of all, lies in a limited set of constituent elements, on the one hand, and in the wealth of possibilities for internal planning solutions, the creation of a non-repeating set of apartments from rooms and volumes, the use of local materials for the construction of external enclosing walls and internal partitions, on the other hand sides. The problem of redevelopment of internal spaces is easier to solve.

The advantages of the KBK prefabricated transomless system from an economic point of view are confirmed by the fact that in Siberia and the Urals there are not isolated cases when contractors using a constructive transomless construction system won tenders from companies building in a "monolith".

The KBK system makes it possible to build both comfortable and "elite" and "social" housing on a single industrial, technological basis. Moreover, the “social” or “elite” purpose of housing is realized at the expense of volume, decoration, etc. At the same time, the KBK system allows (if necessary) without demolition, by redevelopment, to turn a previously “social” house into an “elite” one, or vice versa.

The KBK system is much better adapted to difficult construction conditions. It is more industrial: less in-situ concrete is used at the construction site, which means there are fewer difficulties in winter. There is no need to attract a large staff of qualified employees and special equipment. Thus, the bulk of the problems are transferred to the plant. Ensuring the quality of the carcass largely lies at the plant and depends on the quality of the metal molds. Such a system is less time-consuming and surpasses almost any other in terms of the speed of building construction. So, a team of 5-6 people quietly mounts 200 sq. m (in the presence of reinforced concrete).

If we talk about the technical side of the technology, it can be noted that the structural system provides for the use of continuous (multi-storey) columns with a section of 400 (mm) x 400 (mm) with a maximum length of 9900 (mm). At the junction of columns, forced installation is provided, consisting in pairing the fixing rod of the upper column with the branch pipe of the upper end of the lower column. At the junction of the ceilings (at the height of the floor), the columns are provided with dowel-shaped cutouts, within which the column reinforcement is exposed.

The system of structures of the “KBK” frameless frame provides for the use of factory-made floor panels with maximum dimensions of 2980 (mm) x 2980 (mm) x 160 (mm).

Floor panels, depending on the location in the frame, can be over-column (NP), inter-column (MP) and middle (SP).

Installation of structures is carried out in the following order: columns are mounted and embedded in the foundation; above-column panels are installed and welded to the reinforcement of the columns; then inter-column and middle panels are mounted. When installing the panels, the reinforcing outlets of the ends are combined in such a way that a loop is formed into which the reinforcement is inserted.

The system of structures of the beamless frame is intended for the construction of a wide range of urban structures (residential, public and auxiliary buildings for administrative purposes). Not only high-rise buildings, but also schools, kindergartens, etc. are being built using a prefabricated monolithic girderless system.

Such versatility of the "KBK" system is ensured by a combination of the following properties: a) The supporting basis of the building frame in the "KBK" is made up of columns and floor slabs that act as crossbars, ties or diaphragms are used for stiffening elements, which makes it possible to provide spans of 3.0, 6.0 in buildings m, the height of floors in buildings is 2.8, 3.0, 3.3 and 3.6 with the main grid of columns 6 x 6 m. b) The design of the walls assumes that they perform only an enclosing function. Walls can be designed with floor-by-floor cutting, i.e. rest on the floor slabs and transfer the vertical load from its own weight to the floor slabs of each floor; mounted or self-supporting, which makes it possible to maximize the use of local non-structural materials for enclosing structures, including monolithic walls. c) In buildings with a height of up to 5 floors, under normal construction conditions, a frame structural scheme is used without the use of additional stiffening elements;

The system is designed for the construction of buildings up to 25 floors (up to 75 meters) under normal construction conditions. In areas with seismicity up to 9 points inclusive on a 12-point scale, the use of "KBK" is limited by the requirements of Table 8 * SNiP II-7-81 * "Construction in seismic regions" for frame buildings.

Structural elements of the KBK are manufactured and assembled using a single process equipment. The frame is assembled completely from prefabricated products, followed by monolithic knots; at the final stage, the structure is monolithic.

Thus, the shaping possibilities of the frame in the "KBK" system have a wide range of the number of floors and architectural and spatial solutions. The KBK system allows you to use a wide range of facade plastics, create spatially interesting non-standard layouts that meet the task.

The calculation of the parameters of a beamless frame with flat ceilings is carried out using calculation models implemented by software systems using high-level software products (PC SKAD; PC ING +; PC "LIRA" and others).

One of the main differences between the KBK system and the KBK 2.5 system is the adaptation of the system to the requirements of the current legislation and the receipt of the necessary certificates.

Firstly, the "KBK" system is completed with a separate package of documentation - "Design of a beamless frame for multi-storey residential and public buildings." This set of documentation is certified by the Federal State Unitary Enterprise "TsPP" Moscow for compliance with the requirements of regulatory documents in the field of construction. Certificate No. POCCRU.CP48.C00047 dated April 5, 2007 issued.

Secondly, in order to confirm the fire resistance of building frame elements based on "KBK" in 2008, CJSC "CSN "Fire Resistance-TsNIISK", Moscow, carried out certification tests of the above-column (NP 30-30-8, TU 5842-001-08911161- 2007) and medium (SP 30-30-6, TU 5842-001-08911161-2007) reinforced concrete floor slabs (manufacturer of slabs is FGUP DOKSI pri Spetsstroy Rossii).

Tests of the above-column reinforced concrete slab were carried out under a uniformly distributed load of 700 kg/m2. The heated surface of the above-column slab - the side of the slab with working reinforcement did not reach the limit states and corresponds to a fire resistance limit of at least REI 180. For an average reinforced concrete floor slab, the fire resistance limit was REI 120.

Based on the test results obtained, the Certification Body CJSC TsSN Fire Resistance-TsNIISK, Moscow, issued fire safety certificates for the entire range of floor panels of the KBK frameless frame.

Thirdly, in order to confirm the seismic resistance and assess the suitability of the system of structures of a girderless frame for construction in seismic areas, from August 22 to August 29, 2008, by order of PC KUB-Siberia LLC in Perm, static and dynamic tests of building fragments were successfully carried out. Two experimental three-story fragments of a building made of elements of the "KBK" system were tested in full size with an imitation of the workload in order to justify its use in construction on sites with seismicity up to 7-9 points on the MSK-64 scale. In the construction of the first fragment of the building, ties were used as stiffening elements, in the construction of the second, reinforced concrete diaphragms.

The tests were carried out by the non-profit organization "Russian Association for Earthquake-Resistant Construction and Protection from Natural and Technogenic Impacts" (NO RASS) with the participation of OJSC "12 Voenproekt" (Novosibirsk), LLC "KBK-Ural" (Perm), Federal State Unitary Enterprise "TsPO "at Spetsstroy of Russia (Voronezh).

According to the test results, the seismic resistance of the KBK frame was confirmed up to 9 points - when using reinforced concrete diaphragms as stiffeners, up to 7 points - when using ties. The Russian Association for Earthquake Resistant Construction and Protection from Natural and Technogenic Impacts (RASS) issued a conclusion dated 06.11.2008:

“The KBK building system based on the structures of the Beamless frame is RECOMMENDED for use in the construction of buildings on sites with a seismic activity of 7-9 points on the MSK-64 scale, subject to the restrictions established by the requirements of Table 8* SNiP II -7-81* “Construction in seismic regions” for frame buildings."

The foregoing allows us to draw a number of conclusions.

1. Compliance of the KBK technology with the current legislation allows it to be used without any restrictions and difficulties in any regions of our country, including earthquake-prone ones, while the examination of project documentation in the authorized federal executive authorities and authorities of the constituent entities of the Russian Federation passes without any special features.

2. KBK technology provides complete and reliable predictability of the terms of erection of the building frame. So, already at the stage of the preliminary design, after agreeing on the floor plans, the developer can conclude an agreement with the reinforced concrete plant for the manufacture of structural elements of the building frame, and the extremely limited use of monolithic concrete at the construction site minimizes seasonal changes in the pace of construction, or its suspension. All this allows the developer to correctly assess its capabilities and meet the deadlines and costs specified by the contract, which is especially important when performing work on government orders.

In preparing the article, materials from the sites www.kub-sk.ru, www.12voenproekt.ru were used

karkas-pro.ru

Formwork element of a prefabricated monolithic slab with a frameless frame

The variants of non-removable formwork elements of floors used in the practice of prefabricated-monolithic frame housing construction are considered. A thin-walled reinforced concrete formwork element of a slab with a protruding reinforcing cage is proposed.

Key words: fixed formwork element, flat prefabricated monolithic slab.

The use of flat precast-monolithic slabs in frame housing construction has significant advantages compared to monolithic and prefabricated construction technology. The problems of accelerating the construction time, reducing the laboriousness of the construction of floors, the limited suitability of formwork panels and its preparation for reuse can be solved with the help of prefabricated monolithic floors with non-removable concrete or reinforced concrete elements. The formwork elements act as the bearing base of the floor slab, which ensures its monolithic installation by installing reinforcing elements and laying a layer of concrete mixture. The desire to increase the pitch of the columns of the supporting frame does not allow the use of formwork elements the size of the entire cell from the conditions of transportation, so the question arises of their joint and the development of a floor structure that meets the requirements of reliability and spatial rigidity.

At present, the design solutions adopted in the universal open architectural and construction system of buildings based on a prefabricated monolithic frame with flat ceilings (ARKOS) are widely known. One of the variants of the floor disk of this system includes prefabricated hollow-core slabs, supported by the ends by means of concrete dowels on load-bearing monolithic tee crossbars with a shelf placed in the floor screed (Fig. 1). The prefabricated multi-hollow slab acts as a kind of element of a fixed formwork, both a traditional standard one, manufactured using aggregate-flow technology, and a multi-hollow one without formwork molding. In the case of using the latter, which does not have outlets of working reinforcement, the placement of short reinforcing bars is provided.

Quite interesting is the solution of a prefabricated monolithic floor using wedge-shaped elements made of a rectangular carrier plate and a pyramidal part with side faces inclined at an angle of 5–15º, having relief grooves with a curved surface at the joints (Fig. 2). The slab is assembled from formwork elements, installed with a large base down, the reinforcing mesh is fixed using anchors previously embedded in the elements, and a screed is applied.

Rice. Fig. 1. The design of the prefabricated-monolithic ceiling of the ARCOS system: 1 - monolithic load-bearing crossbar; 2 - concrete dowel of the crossbar; 3 - releases of working reinforcement of multi-hollow slabs; 4 - shelves of the T-section crossbar; 5 - floor screed

Rice. Fig. 2. The design of a prefabricated monolithic floor with fixed wedge-shaped formwork elements: a - sectional view; b - formwork element: 1 - formwork element; 2 - anchors; 3 - reinforcement elements; 4 - two-layer mortar with fiber between layers

Rice. Fig. 3. Design of a prefabricated monolithic floor with non-removable thin-walled slabs: a - layout of elements in plan; b - formwork elements: 1 - above-column formwork element; 2 - the same, span; 3 - reinforcing spatial frame; 4 - reinforcing outlets; 5 - reinforcement elements; 6 - monolithic concrete; 7 - embedded parts

The main disadvantage of the above-described structural solutions for prefabricated monolithic floors is the rather high labor intensity during installation, and in the case of floors with wedge-shaped formwork elements, a significant thickness of the floor and, as a result, the material consumption of the structure.

A variant of a prefabricated-monolithic floor is proposed, consisting of elements of a fixed formwork, which is thin-walled reinforced concrete slabs with reinforcing spatial frames protruding upwards beyond the concrete of the slabs, reinforcing meshes laid on top of prefabricated elements and monolithic concrete (Fig. 3). Protruding reinforcing cages eliminate the need for steel retainers necessary for the design position of reinforcing products and provide reliable adhesion of prefabricated and monolithic floor layers. Such formwork elements have already found application in the construction of prefabricated monolithic frames with reinforced concrete crossbars, as well as in ceilings based on any load-bearing structures: walls, beams, building trusses, both reinforced concrete and steel. Formwork elements of two types are provided: above-column ones with support directly on the columns and having cutouts for passing the reinforcement of the columns and span. Span formwork elements are equipped with bent reinforcing outlets for installation and a joint arranged at a distance of 0.25 of the span length between columns.

The required minimum thickness of the formwork elements, the diameter and pitch of the reinforcing cages depend on the acting forces on the ceiling and the calculated spans and are subject to further study.

Literature:

1. Nikulin A. I. The effectiveness of the use of flat prefabricated monolithic ceilings in frame housing construction / A. I. Nikulin, S. V. Bogacheva / / Technical sciences: problems and prospects: materials of the III Intern. scientific conf. (St. Petersburg, July 2015). - St. Petersburg: Own publishing house, 2015. - p. 70–74.

2. Mordich A. I. Description of the construction of the frame of buildings of the series B1.020.1–7 (ARKOS) and general recommendations for the calculation / A. I. Mordich, V. N. Belevich. - Minsk: Institute BelNIIS, 2005. - 52 p.

3. E. E. Shalis, V. E. Zubko, O. V. Dudko, A. Yu. No. 2109896. 1998.

4. STO NOSTROY 2.6.15–2011 Elements of prefabricated reinforced concrete walls and ceilings with a spatial reinforcing cage. Specifications. - M .: LLC "Scientific Research Institute of Concrete and Reinforced Concrete", LLC Publishing House "BST", 2011. - 49 p.

moluch.ru

crossbarless frame of a building, structure

So, according to the USSR author's certificate No. 1606629, MPK5 E04B 5/43, application date 1988.06.27, a beamless floor is known, including over-column slabs with a central hole for placement on columns, inter-column and middle slabs, having on the joined side faces of each floor slab platforms for successive support of plates one on another. In order to reduce material consumption by reducing the forces on the above-column slab, the platforms for supporting the above-column slabs are made in the form of tables placed in the middle of the side faces, the length of which is determined from the condition l<2b+a, где b - толщина надколонной плиты, a - размер отверстия в надколонной плите по нижней грани.

According to the author's certificate of the USSR No. 1114749, MPK5 E04B 1/18, E04B 1/38, application date 1982.05.04, a crossbarless frame is known, containing columns, floor slabs and joints of columns with floor slabs.

As a prototype, a transomless, capitalless, reinforced concrete frame of a building was chosen according to the patent of the Russian Federation No. 2247812, MPK7 E04B 1/18, E04B 5/43, application date 2001.04. patent owner LLC "Scientific Design Society" KUB ", Moscow.

This is explained as follows.

CLAIM

www.freepatent.ru

Problems of using prefabricated-monolithic floor structures

Currently, buildings with a monolithic ceiling are mainly being built. They are more expensive, for example, the minimum ceiling thickness is 220 mm with a column spacing of 6 x 6 m, the reinforcement consumption is 200 kg per 1 m3 of concrete. If prefabricated floor slabs are used, then the reduced thickness will be 120 mm (with a slab thickness of 220 mm), the consumption of reinforcement per 1 m3 is approximately 30 - 70 kg. Therefore, builders are gradually switching to precast-monolithic floors, which are completely factory-made and are assembled at a construction site with a minimum volume of monolithic concrete.

One of the successful examples is the design of a crossbarless frame (KBK), its developers are: FSUE TsPO at Spetsstroy of Russia, Voronezh and OJSC 12 Voenproekt, Novosibirsk, certificate of conformity No. POCC RU.CP48.C00047 dated 04/05/2007. The KBK frame is a prefabricated monolithic structure. Columns serve as frame racks, floor slabs perform the role of crossbars. Spatial rigidity is provided by a rigid (frame) connection of uncut monolithic floor slabs with columns at the level of each floor. In the case of a frame-braced scheme, stiffening elements are additionally included in the work: connections and diaphragms.

The KBK frame is assembled from system elements that have 100% factory readiness, followed by monolithic nodes. in the operational stage, the structure is monolithic.

The frame is easy to make. Frame elements have a simple geometric shape and a minimum number of standard sizes with the main structural elements of the KBK, it is possible to use flights of stairs, ventilation blocks, elevator shafts, smoke exhaust shafts from other systems.

Basic structural elements.

The KBK system provides for the use of factory-made single-module floor slabs with maximum dimensions of 2980x2980x160 mm, which, depending on their location in the frame, are divided into: NP - above-column, MP - annular, SP - medium.

Fig.1. Floor slabs.

Rigidity diaphragms are installed in the alignment of columns or at the joints of the floor. The diaphragm height corresponds to the floor height, which can be different.

The KBK system provides for the use of continuous (multi-storey) columns with a section of 400x400 mm with a maximum length of 11,980 mm. Floor height can vary from 3 to 11 m.

Ties - reinforced concrete stiffeners with a section of 200x250 mm are installed for the floor height (2.8; 3.0; 3.30 m) between the columns.

Design features.

The KBK system is universal and is intended for the construction of residential, social, administrative and some industrial buildings (structures) in a variety of climatic, relief, seismic conditions.

It is possible to build buildings up to 75 m high (25 floors) in I–V climatic regions (including seismically active up to 8–9 points on the MSK-64 scale). The bearing capacity of the floors allows the use of the framework in buildings with load intensity per floor not exceeding 1200 kg/m2. Normative temporary vertical load on floor slabs is 200 and 400 kg/m2.

Design flaw: the weakening of the most critical above-the-column section with a hole for the column and the difficulty of pairing the plate with the column, which involves welding. Limited span width (up to 6 m) and load.

Proposed design.

The proposed modification of the system allows to mitigate these shortcomings. This is achieved by the fact that the above-column slab is monolithic, and the column with gaps is at the level of the ceiling.

The essence of the design considered in this article will be that the above-column sections of the floor are made monolithic, and the annular and middle sections are assembled from prefabricated elements, while the annular sections of the floor are rigidly fastened to the above-column ones.

This ensures the solidity of the floor, which increases reliability and provides the versatility of the floor, that is, it is suitable for large spans and increased loads.

The division of the floor into above-column, inter-column and middle sections is performed with dimensions (L/2)x(L/2), where L is the span width of the floor cell. The division of the inter-column and middle sections into prefabricated elements is carried out according to the conditions of transportation, that is, a width of not more than 3 m.

On fig. 1 shows a diagram of the division of an overlapping cell with a span of up to 6 m (L ≤ 6 m) into above-column 1, inter-column 2 and middle 3 sections. The above-column sections of the overlap are made monolithic, and the inter-column and middle sections are prefabricated. The dimensions of the sections in this case do not exceed 3 m, therefore, the division of the annular (MP) and middle (SP) sections into prefabricated elements is not required. All items are the same size.

The slab rests either on monolithic columns of floor-by-floor concreting, or on prefabricated columns with gaps at the level of each slab, which are monolithic together with the above-column sections of the slab. This ensures the integrity of the above-column section along the axis of the column.

Rice. 1. Flat prefabricated monolithic ceiling with a span of 6m

The purpose of the conducted research is to find the maximum values of forces and deflections in the structure (Mx, My, Qx, Qy, f), as well as to find out which of these schemes will be more convenient with respect to these five parameters.

Seven schemes of floor slabs are considered. This includes various loading options, as well as the support of individual sections of the structure.

Initial data for scheme 1: slab 6 x 6m, supported by 4 columns at the corners, slab thickness t=160mm.

Rice. 2. Calculation scheme 2

This diagram shows the maximum value of forces and deflection in a 6 x 6m cell when it is loaded with a constant load F=10kN/m. The results can be seen in Table 1.

Scheme 2, 3 and 4: floor slab 21 x 21 m with a column spacing of 6 m, floor thickness t=160mm. They have different loading options. In scheme 5, the hinge support of the middle plate. In scheme 6, the above-column plate is t = 180 mm thick, the inter-column plate is 160 mm, and the middle one is 140 mm.

The last scheme is the same as the sixth one with a variable value of plate thicknesses, but we reinforce the above-column plate with a rigid insert from an I-beam I 14.

Comparing the first and second diagrams with each other, it can be seen that the maximum moment and lateral force have increased significantly, but at the same time, the deflection value has decreased by 59.9% from the original. This is due to the following factors:

different scheme and dimensions of the structure, this shows the difference in the values of forces in the places where the structure is supported;

the work of one, free-standing cell differs from the work of several cells together, so "cellular" structures are convenient in construction.

Schemes 3 and 4 show how the structure works under a particular load.

The most successful scheme is scheme 5. Analysis of the results shows that the bending moments have become significantly less compared to scheme 2 by 73.2%, and the transverse forces by 93%, the deflection value has decreased by 65.4%.

If we take scheme 6, we see that the values of moments and transverse forces do not differ significantly: Mmax and Qmax decreased by 10.5% and 45.5%, respectively, while the deflection, on the contrary, increased by 3.7%.

In scheme 7, Mmax decreased by 58.8%, Qmax - by 89.3% and deflection f by 42.8% in comparison with scheme 2.

Calculation data in CAD "Lira"

Based on the above, the following conclusions can be drawn:

changing the floor section (scheme 6) does not "unload" the structure much, while the average thickness of the structure is 160 mm, which corresponds to scheme 2. Also, the creation of such a floor will be more laborious. Therefore, this scheme is not rational.

the most rational choice is scheme 5 with the hinged support of the middle plate. In addition, it is easier to pair the plates with each other. In this case, the design satisfies the objectives of the task.

Rice. 3. Calculation scheme 1

Rice. 4. Calculation scheme 3

Rice. 5. Calculation scheme 4

Rice. 6. Calculation scheme 5

Rice. 6. Calculation scheme 6

Rice. 7. Calculation scheme 7

Literature:

Potapov Yu. B., Vasiliev V. P., Vasiliev A. V., Fedorov I. V. Reinforced concrete floors with a slab supported along the contour // Industrial and civil construction, 2009. - No. 3. - With. 40-41.

GOST 8239-89: Hot-rolled steel I-beams. - Input. 07/01/1990. - Ministry of Ferrous Metallurgy of the USSR, GOSSTROY of the USSR, Central Research Institute of Building Structures. - 4 s.

OOO KUB-STROYKOMPLEKS. Prefabricated monolithic frame. Reliable construction system for investor and developer. – URL: http://www.kub-sk.ru/userfiles/File/KUB_Tehnology_nov.PDF. Date of access: 16.10.2011

moluch.ru

Crossbarless frame of a building, structure

The invention relates to the field of construction, in particular to the structures of prefabricated frame buildings and structures. The technical result of the invention is to increase the rigidity and strength characteristics of the frame. Crossbar-free frame contains columns, over-column floor slabs resting on columns, inter-column floor slabs located between above-column slabs, nodes for connecting columns with above-column floor slabs and nodes for connecting floor slabs to each other. The columns located at the corners of the buildings and at the intersections of the longitudinal and transverse walls are shaped with a corner, tee or cruciform cross-section according to their location. Each node for connecting columns with above-column floor slabs is made in the form of embedded parts connected to the column reinforcement and installed on the peripheral sections of the cross-section of the curly column, as well as vertical rods passed through holes in the above-column floor slab and connected to the embedded parts of the columns. 2 w.p. f-ly, 16 ill.

The invention relates to the field of construction, in particular to the structures of prefabricated frame buildings and structures, and can be used in the construction of residential, civil, industrial buildings and structures with beamless frames.

Frameless frames are currently an alternative to traditional schemes for the construction of prefabricated frame buildings and structures. An example of the use of girderless frames is the construction system of a girderless fully prefabricated frame of prefabricated frame buildings of the KUB-2.5 series, which has been approved and approved by the State Construction Committee of the Russian Federation. Ministry of construction, architecture and housing and communal services of the Russian Federation.

A series of prefabricated frame buildings KUB-2.5 was mastered by KUB System LLC, KUB Stroy LLC, PSK-KUB LLC (Moscow), KUB System SPb LLC, KUB Stroy SPb LLC (St. Petersburg).

The KUB-2.5 construction system differs from traditional prefabricated frame systems, first of all, by the absence of crossbars (the role of which is played by floor slabs), as well as the use of columns without protruding parts. Floor slabs, depending on the location, are divided into above-column, inter-column and middle. The spatial rigidity of the structure is ensured by the monolithic connection of the elements (floor slabs and columns) and, if necessary, by the inclusion of connections and diaphragms in the system. The KUB-2.5 frameless frame system is based on the design of the junction of two main elements - a floor slab and a column using an embedded part - a steel shell connected to the floor slab reinforcement. Concrete in this node works under conditions of all-round compression, as a result of which its self-hardening occurs. This makes it possible to exclude bath welding at the junction of columns. There are only mounting seams in the knot.

The installation of the frame is carried out in the following order: first, the columns are installed and aligned, then the over-column floor slabs are installed at the design level, after which the inter-column and middle floor slabs are mounted “dry”. After installing the reinforcement in the seams between the slabs, the junction points of the knee slabs and columns, as well as the seams between the floor slabs, are monolithic with concrete.

The KUB-2.5 frameless construction system can be used for the construction of almost the entire range of structures: residential and public buildings, industrial facilities, warehouse complexes, etc.

The KUB-2.5 frameless frame building system, in comparison with traditional schemes for the construction of prefabricated frame buildings and structures, has the following main advantages:

High level of industrialization - the technology of manufacturing building elements 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:

High installation performance - only two types of simple and labor-intensive connections are used: "column-plate" and "plate-plate", that is, the minimum physically possible number, which contributes to the acceleration of installation: no special training of installers is required, all installation procedures are standard ; a team of 5 people assembles up to 300 m2 of floors per shift:

Reducing the number of welding work - welding work is performed only for welding four connecting parts in the "column-plate" assembly:

Reducing the amount of concrete during the installation process - the amount of concrete is minimal, since concrete is required only for sealing the joints between the slabs and embedding the "column-slab" unit;

Variety and freedom of architectural solutions - interfloor ceilings can take a variety of forms, thereby allowing you to solve any architectural problems in the design of residential, public or industrial buildings.

Structures of beamless frames of buildings and structures are widely described in patent information.

On the columns installed at a distance of 2l from each other, where l is the length of the floor slab, above-column floor slabs are mounted, having a hole in the central part. The side faces of the above-column slabs are made in the form of a step, the middle part of which has a greater height than the extreme parts, and forms a support table. Intercolumn plates rest on the above-column slabs with their two opposite edges. On the side faces of these slabs, “quarters” are formed along their entire length, and on the faces with which these slabs rest on the over-column slabs, the “quarters” are selected from below, and on the other two faces - from above, thereby forming the supporting surfaces on which the middle plates. These plates on the side faces also have quarters selected along the entire length, but these quarters are selected only from the bottom side. The unit for connecting columns with above-column floor slabs includes an opening in the above-column slab, in which the column is placed. The specified hole has a frame in the form of a steel shell. After installing the column in the hole, the connection node is monolithic.

Installation of the ceiling is carried out in the following order.

Over-column plates are installed on top of the columns.

Then, inter-column slabs are laid on the above-column slabs in such a way that the "quarters" of these slabs, formed on opposite faces, rest only on the tables located in the middle part of the side faces of the above-column slabs. The middle plates, in turn, are installed on the supporting surfaces of the intercolumn plates. Thus, the entire space is covered.

The common features of the analogue and the proposed solution are: a beamless frame of the building, a structure containing columns, over-column floor slabs resting on columns, inter-column floor slabs located between over-column floor slabs, nodes for connecting columns with knee-high floor slabs and nodes for connecting floor slabs to each other.

With the specified design of the joint between columns and above-column floor slabs, the rigidity of the frame and resistance to bursting loads are limited, since the support of the above-column floor slab on the column is carried out only through a connecting node artificially created in the conditions of the construction site, localized within the cross section of the column, the geometry and design features of which do not allow to perceive significant bending moments and axial loads. The need for monolithic connection of columns with above-column floor slabs increases the complexity of installation and the consumption of concrete at the construction site.

According to the author's certificate of the USSR No. 1114749, MPK5 E04B 1/18, E04B 1/38, application date 1982.05.04, a girderless frame is known, containing columns, floor slabs and junctions of columns with floor slabs.

SUBSTANCE: joint of column and floor slab contains a prefabricated column made in height with a concrete break at the floor level, and a prefabricated floor slab made with a hole with beveled ends in its lower part (to pass the column) and a shell rigidly attached along the perimeter of the hole to the working reinforcement of the floor slab and equipped with additional rods (a) located in the lower zone of the slab.

In addition, the floor slab is equipped with rods (b) connecting the working reinforcement of the slab with additional rods (a) of the shell. The ends of the opening of the floor slab are made with a bevel in its upper part to form a triangular prism. The unit is equipped with flat trapezoidal elements connecting the working reinforcement of the column with the upper part of the shell of two adjacent ends of the opening of the floor slab.

The assembly cavity is monolithic with concrete.

The rods (b) provide an increase in the bearing capacity of the floor slab in the support zone for punching, and also perceive the bending moment in the lower zone of the floor slab under seismic loads. The connection of additional rods (a) of the shell to the reinforcement of the slab creates a combined reinforcement of the support zone for shearing with a minimum amount of metal.

Installation of the assembly at the construction site is carried out as follows.

After installing the column, a T-shaped fixture is installed in the mounting hole of the column, made in the form of a pipe with a beam, at the ends of which there are threaded bushings for screws. After that, the slab is lifted by a crane, put on a column and mounted on the screws of the mounting fixtures. By moving the screws, the floor slab is set to the design position. Next, trapezoidal elements are welded to two adjacent sides of the shell in its upper part and to the working reinforcement of the column at the place of concrete rupture.

Concreting of the node cavity is carried out, for example, with a concrete pump. After the joint has been sealed and the required strength has been achieved, the mounting fixture is removed.

The shell adjacent to the column is made in the form of a triangular prism, which creates a key effect, increasing the rigidity of the assembly and its punching strength. Attaching the shell to the column reinforcement using trapezoidal elements will allow transferring the bending moment from the ceiling to the column, which also increases the rigidity and reliability of the assembly.

The common features of the analogue and the proposed solution are: a beamless frame of the building, a structure containing columns, over-column floor slabs based on columns, junctions of columns with knee slabs.

As in the previous analogue, the design of the junction of columns with above-column floor slabs limits the rigidity of the frame and resistance to bursting loads for the above reasons, and the need to monolithic the junction increases the complexity of installation and the consumption of concrete at the construction site.

As a prototype, a transomless reinforced concrete building frame was chosen according to the patent of the Russian Federation No. 2247812, MPK7 E04B 1/18, E04B 5/43, application date 2001.04.03. patent owner LLC "Scientific Design Society" KUB ", Moscow.

The crossbarless reinforced concrete frame of the building contains above-column and inter-column slabs having loop outlets on the ribs and grooves symmetrically located relative to each other, along which reinforcement is installed through the overlaps of the loop outlets of adjacent slabs, and prefabricated columns passing through the holes in the above-column slabs, in which longitudinal reinforcement is exposed at the places of installation of above-column slabs. The frame has the following features that determine its novelty at the priority date:

On the ribs of the above-column slabs in their lower part, shelves and discretely located support tables are formed, and in the upper part of the longitudinal ribs of adjacent inter-column slabs, counter consoles are made, while the length of the support tables and consoles is equal to the width of the shelf, and the loop outlets have a length not exceeding the width of the shelf :

The above-column plate is equipped with a shell mounted in its hole, attached to the working reinforcement of the column;

At the intersection of the above-column floor slabs and columns and at the junction of two separate sections of the columns with the above-column slabs, the exposed reinforcement is monolithic with the exposed reinforcement of the above-column floor slab;

At the junction of two separate sections of columns with above-column slabs, the exposed reinforcement of the upper column is made in the form of a loop outlet, and the lower one is in the form of reinforcing bars.

The girderless, capitalless, reinforced concrete frame of the building consists of columns, directly on which the above-column slabs are "put on" and supported. Intercolumn slabs are supported on these above-column slabs during the installation of the ceiling. Both types of slabs are made flat, devoid of ribs, capitals and any other thickenings in the zone of support on columns or on each other. The columns are made of a constant section in height, devoid of any capitals or collars protruding beyond their dimensions in the zone of support of the floor slabs.

Longitudinal reinforcement is exposed at the places where the knee plates are installed in the column, and the hole in the above-column plate is provided with a steel shell built into it during manufacture. In the case when a column joint is arranged in height at the level of the above-column slab, a looped release of reinforcement is made from the upper part of the column, and reinforcing bars are made from the lower part of the column. When combining the above-column slab with the column and parts of the column with each other, their joint is monolithic with concrete.

Floor slabs along the periphery in the lower part have shelves. These shelves are placed in such a way that when docked with an adjacent floor slab, the shelf is only at one of the adjacent slabs. Reinforcing loop outlets are made in the ribs of the floor slabs, the length of which does not exceed the width of the shelf. When mounting the plates between the loop outlets overlapping each other, horizontal rods were omitted, located vertically in the same plane and monolithic with concrete. In addition, support tables discretely located along the length of the rib are formed on the ribs of the above-column slabs in their lower part, and counter consoles are made in the upper part of the longitudinal ribs of adjacent inter-column slabs, with the support tables and consoles located in the plane of the plates and the length of the support tables and consoles is equal to the width shelves. When installing the slabs, the tables and consoles are monolithic with concrete.

When installing floor slabs, mounting racks are used. Plates are made in the version of single-module and two-module panels. In two-module slabs, the length of the larger side is equal to the distance "along the axes" between adjacent columns, and in single-module slabs, the length of the larger side is equal to half the distance "along the axes" between adjacent columns.

The installation of the frame is carried out in the following order: first, the columns are set in the design position. Then, knee plates are mounted on them, after which two-module intercolumn plates are installed. Two-module slabs can have a combined design, when one part of the slab is equipped with a hole for passing the column and act as a column plate, and the other part of this slab is devoid of such an opening. In the ordinary version of a two-module slab, there is no hole for passing the column at all. For a better perception of mounting loads by the columns, a single-module knee plate is first installed, and two-module plates, whether combined or ordinary, are already supported on it. With asymmetrical support of the slabs or with one-sided application of a load to them, which usually happens on the extreme axes of the building, mounting racks are used. Racks are removed only after the ceiling of the next floor is mounted, monolithic with concrete and the concrete has gained at least 70% of the design strength.

The above-column slab is installed on the column using a mounting jig, which is pre-installed in the hole made in the column at the level of the floor slab bottom mark. The above-column slab installed at the design level is attached to the column by welding the shell with the working reinforcement of the column, using steel intermediaries. If at the installation level of the above-column slab, the upper and lower parts of the column are joined, then the loop reinforcement of the upper column is welded to the rods of the lower column. Then the junction node is monolithic with concrete with careful compaction.

Installation of intercolumn plates in the design position is carried out on supporting tables. During the installation of intercolumn plates, the reinforcing loop outlets protruding from their ribs overlap each other, forming a closed oval ring through which horizontal rods are passed, located one above the other in a vertical plane. Then the joint is sealed with concrete. During the installation of the slabs, a shelf protruding in the lower part of the ribs closes the gap between the slabs, forming a channel filled with concrete.

In low-rise buildings up to 4 floors high, the cross-section of a reinforced concrete column can be related as 1:2, and thus the column can be "hidden" in the thickness of the wall without protruding from its plane.

The common features of the prototype and the proposed solution are: a beamless frame of the building, a structure containing columns, over-the-knee floor slabs resting on the columns, inter-column floor slabs located between the over-column floor slabs, nodes for connecting columns with over-the-knee floor slabs and nodes for connecting floor slabs to each other.

The design of the beamless frame according to the prototype does not allow to fully realize the above-mentioned potential advantages of building systems of beamless frames for the following reasons:

With the specified design of the joint between columns and knee slabs, the rigidity of the frame and the resistance to bursting loads are limited, since the support of the over-column floor slab on the column is carried out only through a connecting unit artificially created in the conditions of the construction site, localized within the cross section of the column, the geometry and design features of which do not allow to perceive significant bending moments and axial loads; it is noted that the number of storeys according to the frame scheme is limited to 5 floors, with a building height of more than 5 floors, connection and diaphragm schemes are required;

The need for monolithic connection of columns with knee slabs increases the complexity of installation and the consumption of concrete at the construction site; in addition, the monolithic of the specified node, as the most critical node of the frame, requires a high production culture and strict control, which is limited in the conditions of the construction site;

The ability to perform installation work at sub-zero temperatures is problematic, since the necessary heating of concrete in the process of embedding the joints of columns with column slabs is a problem.

The invention is based on the task of improving the frameless frame of a building, a structure in which, due to the design features of the execution, an increase in the rigidity and strength characteristics of the frame is provided, as well as a reduction in the labor intensity of installation work while maintaining all the advantages of building systems of frameless frames.

The problem is solved by the fact that in the frameless frame of a building, a structure containing columns, above-column floor slabs based on columns, inter-column floor slabs located between above-column floor slabs, nodes for connecting columns with above-column floor slabs and nodes for connecting floor slabs to each other, according to of the invention, the columns located at the corners of buildings and at the intersection of the longitudinal and transverse walls are made figured with a corner, tee or cruciform cross section, according to their location, and each node for connecting columns with above-column floor slabs is made in the form of embedded parts connected to the reinforcement of the column and installed on the peripheral sections of the cross-section of the curly column, as well as vertical rods passed through the holes in the above-column floor slab and connected to the embedded parts of the columns.

These features are essential features of the invention.

Technologically, embedded parts are made in the form of isosceles corners installed at the end sections of the column and recessed with their top into the body of the column, and a layer of mortar is applied between the above-column floor slab and the ends of the columns to eliminate mounting gaps.

The essential features of the invention are in a causal relationship with the achieved technical result.

Thus, the distinguishing features of the invention (columns located at the corners of buildings and at the intersection of longitudinal and transverse walls are made figured with a corner, tee or cruciform cross-section, according to their location, and each connection point of columns with above-column floor slabs is made in the form of mortgages, parts connected to the reinforcement of the column and installed on the peripheral sections of the cross section of the curly column, as well as vertical rods passed through the holes in the above-column slab and connected to the embedded parts of the columns) together with the essential features common to the prototype provide increased rigidity and strength characteristics of the frame , as well as reducing the labor intensity of installation work while maintaining all the advantages of building systems without crossbar frames.

This is explained as follows.

The use in the frame in the corners of buildings and at the intersection of the longitudinal and transverse walls of columns shaped in cross section makes it possible to support floor slabs on the ends of columns with an increased support area without the use of protruding cantilever elements, both on columns and on floor slabs.

Implementation of the connection point of the column with the above-column floor slab in the form of embedded parts connected to the column reinforcement and installed on the peripheral sections of the cross-section of the figured column, as well as vertical rods passed through the holes in the above-column floor slab and connected to the embedded parts of the column, ensures a reliable connection of the columns and above-column slab without embedding the connection unit, which increases the productivity of installation and reduces the consumption of concrete during installation.

The support of the above-column floor slab on the figured cross-section of the column, characterized by a significant moment of inertia of the section, as well as the connection of the columns with the help of the specified embedded elements and rods passed through the holes in the above-column slab, significantly increases the resistance of the junction of the column with the above-column floor slab to bending moments and punching forces , which increases the strength characteristics and rigidity of the frame.

The manufacture of frame elements is maximally transferred to workshop conditions, thereby significantly reducing the risks of both natural and human factors at the construction site.

All that is noted above provides the possibility of increasing the strength characteristics and rigidity of the frame, increasing the productivity of installation work and reducing the consumption of materials at the construction site.

The following is a detailed description of the claimed frameless frame of the building, structure with links to the drawings, which show:

Figure 1 - Crossbarless frame of the building, structures, curly column with a cruciform cross section.

Figure 2 - Crossbarless frame of the building, structures, figured column with a T-shaped cross section.

Figure 3 - Crossbarless frame of the building, structures, curly column with a corner cross section.

Fig.4 - Crossbarless frame of the building, structure, schematic diagram.

Fig.5-7 - Crossbarless frame of the building, structures, examples of wiring diagrams with different combinations of curly columns.

Fig.8 - Crossbarless frame of a building, structure, longitudinal section of the connection node of the above-column slab with a figured column with a cruciform cross section.

Fig.9 - Crossbar frame of a building, structure, section A-A in Fig.8.

Fig.10 - Crossbarless frame of a building, structure, a longitudinal section of the connection node of the above-column slab with a figured column with a T-shaped cross section.

Fig.11 - Frameless frame of the building, structure, section B-B in Fig.10.

Fig.12 - Crossbarless frame of a building, structure, a longitudinal section of the connection node of the above-column slab with a figured column with an angular cross section.

Fig.13 - Crossbarless frame of the building, structure, section B-B in Fig.12.

Fig.14 - Crossbarless frame of the building, structure, view D in Fig.8, 10, 12.

Fig.15 - Crossbarless frame of the building, structure, section D-D in Fig.8, 10, 12.

Fig.16 - Crossbarless frame of a building, structure, an example of connecting floor slabs to each other.

Cross-beam frame of the building, structures containing curly columns made with a cruciform 1, tee 2, corner 3 cross-section (figure 1, 2, 3), over-column floor slabs 4, based on columns 1, 2, 3, inter-column floor slabs 5 located between the over-column floor slabs 4, nodes 6 for connecting columns 1, 2, 3 with over-column floor slabs 4 and nodes 7 for connecting floor slabs 4, 5 to each other. Curly columns 1, 2, 3 are located in the corners of buildings and at the intersection of the longitudinal and transverse walls, as shown in the schematic diagram in Fig.4. Figure 5, 6, 7 shows examples of wiring diagrams of frames with different combinations of curly columns 1, 2, 3. with a corner section and figured columns 2 with a T-section, figure 5 - figured columns 3 with a corner section, figured columns 2 with a T-section and figured columns 1 with a cruciform section.

Floor slabs 4, 5 are made flat, without ribs, capitals and any other thickenings in the zone of support on columns 1, 2, 3 or on each other. Columns 1, 2, 3 are also made of constant cross-section in height, devoid of any capitals or collars protruding beyond their dimensions in the support area of the above-column floor slabs 4.

Each node 6 for connecting columns 1, 2, 3 with above-column floor slabs 4 is made in the form of embedded parts 8 connected to reinforcement 9 of columns 1, 2, 3 and installed on peripheral sections 10 of the cross section of figured columns 1, 2, 3, as well as vertical rods 11 located in the holes 12 of the above-column floor slab 4 and connected to embedded parts 8 of columns 1. 2, 3. All these connections are made in the form of welding 13. Embedded parts 8 are made in the form of isosceles corners 14 installed at the end sections of the column 1 , 2, 3 and recessed with their top into the body of columns 1, 2, 3 and connected by welding 13 with reinforcement 9 of column 1, 2, 3. In node 6, the connection of columns 1, 2, 3 with above-column floor slabs 4 between the above-column floor slab 4 and the ends of the columns 1, 2, 3 applied layer 15 mortar. The design features of the connecting node 6 are shown in Fig.8-13, including Fig.8-9 - for column 1. Fig.10-11 - for column 2, Fig.12-13 - for column 3. On Fig.14-15 shows sections and views of the connecting node 6.

Knots 7 for connecting floor slabs 4, 5 are made using well-known design and technological solutions. So, in Fig.16 shows an example of the node 7 connection of floor slabs 4, 5. Floor slabs 4, 5 have in the lower part of their ribs shelves 16, located on the entire length of the rib. In the ribs of the floor slabs 4, 5, reinforcing loop outlets 17 are made, the length of which does not exceed the width of the shelf 16. When mounting the plates between the loop outlets 17, which are overlapped with each other, horizontal rods 18 are omitted, embedded in concrete 19. Other solutions of the connecting node are also possible. 7.

The frame is mounted as follows.

Columns 1, 2, 3 are set in the design position. Then, above-column slabs 4 are mounted on them. layers 15 of mortar to eliminate mounting gaps. Vertical rods 11 are passed through the holes 12 in the above-column plate 4, which are welded by welding 13 to the embedded parts 8 installed on the peripheral sections 10 of the cross section of the figured columns 1, 2, 3. The number of welding operations is minimal - welding operations are performed only for welding vertical rods 11 to embedded parts 8 (four, six, eight welds 13 for corner 3, tee 2. cruciform 1 columns, respectively). Monolithic connection node 6 is not required, which reduces the consumption of concrete during installation.

After the installation of the above-column slabs 4, the inter-column floor slabs 5 are mounted. The floor slabs 4, 5 are joined together, as shown in Fig.16. When this loop releases 17 are overlapped with each other. Horizontal rods 18 are passed between the loop outlets 17. The seam is monolithic with concrete 19.

When installing floor slabs, any temporary mounting racks are used (not shown in the figures for simplicity).

All installation procedures are standard, no special training of installers is required.

1. Crossbarless frame of a building, a structure containing columns, over-column floor slabs resting on columns, inter-column floor slabs located between over-column floor slabs, nodes for connecting columns with above-column floor slabs and nodes for connecting floor slabs to each other, characterized in that the columns, located in the corners of buildings and at the intersection of the longitudinal and transverse walls, are made figured with a corner, tee or cruciform cross-section according to their location, and each connection point of columns with above-column floor slabs is made in the form of embedded parts connected to the reinforcement of the column and installed on peripheral sections of the cross section of the curly column, as well as vertical rods passed through the holes in the above-column floor slab and connected to the embedded parts of the columns.

2. Crossbarless frame according to claim 1, characterized in that the embedded parts are made in the form of isosceles corners installed at the end sections of the column and recessed with their top into the body of the column.

3. Crossbarless frame according to claim 1, characterized in that at the connection point of columns with above-column floor slabs, a layer of mortar is applied between the above-column floor slab and the ends of the columns.

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The method of erecting a crossbarless frame

The invention relates to the field of construction, in particular to a method for erecting a frameless building frame. The technical result of the invention is to reduce the construction time of the building. In the method of erecting the frame of a building, the connection of adjacent columns with floor slabs is carried out by means of reinforcement that is prestressed during installation. Before tensioning each lower disk of floor slabs, columns are installed together with technological equipment. Then racks are mounted under floor slabs, they are leveled together with mounting tables on columns, plywood strips are laid on these tables and racks and floor slabs, side beams, balcony slabs are mounted. Next, the cement-sand mortar is laid in the seams between the grooves of the floor slabs and the faces of the columns. After gaining 75% of the design strength with a solution, the lower disk of the floor slabs is pre-tensioned, excluding the displacement of the columns from the design position. 4 ill.

The invention relates to the field of construction and is intended for the construction of buildings with reinforcement tension in building conditions.

A known method of erecting the frame of the building [AS No. 1386716, Appl. 01/17/1986], including the installation of columns, laying floor slabs and crossbars, combining the frame elements with prestressed reinforcement and subsequent monolithic joints between the frame elements, and after laying the floor slabs in the alignment between the columns, metal shields are installed on the outside of the frame, and after tension reinforcement, the space between floor slabs and shields is concreted with the simultaneous formation of monolithic crossbars and sealing of joints with floor slabs.

The disadvantage of the known method is the high material consumption and labor intensity associated with the installation of metal shields, as well as the availability of special equipment and fixtures, while this method requires technological breaks necessary to gain strength of the concrete mix during the installation of the next floor of the building.

A well-known invention is a method implemented by a prefabricated frame structure made of prestressed concrete [SFRY Patent No. 25452, published on March 31, 1996], in which the transfer of prestressing forces is carried out on concrete, where, before tensioning the reinforcement, it is necessary to ensure the solidity of the floor disk by filling (caulking) with cement mortar joints between columns and prefabricated floor slabs until the required at least 70% of the design strength of the mortar in the joints is reached.

The disadvantage of the known method is the presence of a technological break, immediately before the tension of the reinforcement necessary for the hardening of the solution in the contact joints during the installation of the next disk of floor slabs.

Closest to the claimed method is the method of erecting a beamless frame with prestressing of the floors [Patent RU No. 2147328, Appl. 04/09/1998], including columns and floor slabs resting on them, the combination of which is carried out by prestressing reinforcement during installation, while mounting spacers of adjustable length are installed between adjacent columns above or below the floor level, to which the forces of prestressing reinforcement are transmitted. These mounting (inventory) spacers are placed along the axes of the building, resting on them the formwork of a monolithic ceiling. This makes it possible to exclude technological breaks necessary to fill the joints between prefabricated slabs and columns with mortar and the time for this mortar to harden. The transfer of the tension force from the spacers to the ceiling can be carried out with a delay of 1-2 floors from the installation work on the construction of the frame.

The disadvantage of the known method of stressing the frame floors is the consistent use of special mounting struts, which makes the construction material-intensive and also very laborious, since it requires both installation and dismantling of these struts on the floors of the building under construction.

The task of the developed method for erecting a girderless frame with floor prestressing is to improve the construction technology by mounting the upper disks of floor slabs together with laying a cement-sand mortar in the joints between the grooves of the floor slabs and the faces of the columns and the seams between the floor slabs before prestressing each lower disk of the floor slabs.

Technical results that can be obtained using the proposed method:

The construction of buildings ahead of 3 floors compared to the laying of walls and internal partitions;

Reducing the construction time of buildings;

Exclusion of technological breaks in construction;

Simultaneous performance of several installation works;

Fixation of columns in the design position without the use of additional devices;

Elimination of displacement of columns from the design position when the lower disk of floor slabs is tensioned;

Exclusion of the effect of the "reverse wedge" between the grooves of the floor slabs and the faces of the columns;

Increasing the strength of the building structure and, accordingly, the safety of its operation.

The solution of this problem and the achievement of the above results became possible for the method of erecting a girderless frame, including sequential prestressing of the floor of each floor by connecting adjacent columns with floor slabs by means of reinforcement prestressed during installation, which is carried out due to the fact that before tensioning each lower disk of floor slabs columns are installed together with technological equipment for mounting the upper disk of floor slabs on these columns, while racks are mounted under the floor slabs, they are leveled together with mounting tables on the columns, then plywood strips are laid on these tables and racks and floor slabs, side beams are mounted , balcony slabs, then the cement-sand mortar is laid in the seams between the grooves of the floor slabs and the faces of the columns and the seams between the floor slabs, after gaining 75% of the design strength with a mortar, the lower disk of the floor slabs is pre-tensioned, excluding the displacement of the columns from the design position. At the same time, the installation of floor slabs, side beams, balcony slabs is carried out so that the gap between the grooves of the floor slabs, balcony slabs, side beams and the sides of the columns is 2 ÷ 3 cm, and at the same time, reinforcement is prepared along the length to tension the lower disk of the floor slabs by measuring the distance along the axes of the columns after mounting the upper disk of the floor slabs.

An inventive step is the creation of a high-tech method for the erection of buildings and structures with a beamless frame, which ensures the exclusion of technological interruptions and allows the successive erection of disks of floor slabs ahead of them by 3 floors compared to the erection of walls and partitions of a building by fixing columns with grooves of floor slabs, side beams , balcony slabs of the upper disks of floor slabs with cement-sand mortar until each lower disk of floor slabs is tensioned. This makes it possible to pre-delivery building materials for the construction of walls and partitions on the erected disk before the installation of the subsequent disk of floor slabs.

Fixing the columns in the design position with laying the cement-sand mortar in the contact joints between the grooves of the floor slabs and the faces of the columns and the seams between the floor slabs with a set of 75% of the design strength by successively erecting disks of the floor slabs to the tension of the previous one allows to ensure a clear equality of gaps between the faces of the columns and grooves of floor slabs, balcony slabs, side beams, and this does not require special equipment and devices.

The proposed method of erecting a frame without crossbars makes it possible to exclude the occurrence of residual deformations due to micro-displacements during the transfer of reinforcement stress to concrete in the case of using inventory (mounting) spacers, which is especially important in the critical zone of the junction of the faces of the columns with the grooves of the floor slabs. Fixation of the columns by the claimed method prevents their displacement from the design position when the lower disk of the floor slabs is tensioned, which makes it possible to avoid the "reverse wedge" effect, since external forces act on the columns, and they still perceive the weight of the floor slabs, taking into account their design positioning.

The claimed invention is illustrated by the following figures:

Fig.1. The facade of the building, including columns fixed with mounting ties, floor slabs, balcony slabs laid on mounting tables, mounting racks and cable fittings (side view).

Fig.2. The frame of the building, including columns, floor slabs, balcony slabs, side beams (top view).

Fig.3. A fragment of the connection between the floor slab and the column with a technological gap between them and the cable reinforcement (section).

Fig.4. A fragment of the connection of floor slabs and side beams with a column by means of cable reinforcement (top view).

The frame of the building is formed by connecting columns 1 with floor slabs 2 by means of tension cable reinforcement 3 (figure 1), which is mounted from the installation of columns 1 with mounting tables 4 pre-attached to them in foundation glasses (not shown) and these columns are positioned in the design position by means of mounting screeds 5, then carry out the installation of mounting racks 6 in the design position. Leveling of the mounting racks 6 and mounting tables 4 is carried out to the design mark, then strips of plywood (not shown) are laid on the indicated racks 6 and tables 4. After that carry out the layout of floor slabs 2, balcony slabs 7, side beams 8 in the design position (figure 1-2). Then, contact joints 9 are embedded between the grooves (not shown) of floor slabs 2, balcony slabs 7, side beams 8 and faces (not shown) of columns 1 and at the same time contact joints 10 between floor slabs 2. When the solution reaches 75% of the design strength in embedded contact seams 9 and 10 (figure 3) pre-tension the cable reinforcement 3 with subsequent transfer of stress to concrete, thus forming a disk (not shown) of floor slabs 2. Having mounted several disks of floor slabs 2 on columns 1 at the level of passage through them rope fittings 3 (figure 1-4), proceed with the installation of the following adjacent columns installed earlier, similarly to the described method, carrying out the construction of the building. Moreover, the pre-tensioning of the rope reinforcement 3 of the disk of floor slabs 2 is carried out after the installation of the next disk of floor slabs 2 above it on mounting tables 4 and mounting racks 6 with contact seams 9 and 10 imbedded and having gained 75% of the design strength. floors 2, the next one is installed before the tension of the two previous ones. This allows you to fix the columns 1, which have gained design strength, with cement-sand mortar and avoid their displacement from the design position when each lower disk of floor slabs is tensioned, thereby stabilizing the technological gap between the grooves (not shown) of floor slabs 2, balcony slabs 7, side beams 8 and faces (not shown) of columns 1.

With this installation method, construction work is carried out 3 floors ahead of the construction of walls and partitions of the building (not shown), this makes it possible to eliminate technological interruptions during the construction of the building and ensure the simultaneous continuous execution of several construction and installation works. At the same time, before the installation of the next disk of floor slabs, building materials for the construction of walls and internal partitions (not shown) are delivered to the previous disk of floor slabs.

This method stabilizes the technological gap between the faces of the columns 1 and the grooves of the floor slabs 2, balcony slabs 7, side beams 8, which is in the range from 2 to 3 cm, and the fixation of the columns 1 when the previous disks of the floor slabs 2 are tensioned does not require special devices and materials , as well as additional operations for its implementation.

The practical applicability of the invention is shown on the example of a specific use.

The erection of the frameless frame of the building is carried out with the installation of columns together with technological equipment in the form of mounting tables in foundation glasses, then the mounting racks are placed in the design position under the floor slabs. Immediately after this, the mounting racks and tables are leveled and the plywood strips are subsequently laid, after which the floor slabs, balcony slabs and side elements are laid out to design marks, while the installation is carried out so that the gap between the grooves of the floor slabs and the faces of the columns is 2- 3 cm. Then, the contact joints are sealed with a cement-sand mortar between the faces of the columns and the grooves of the floor slabs, balcony slabs, side beams and between the floor slabs. Preliminary, the reinforcement is prepared along the length, measuring the distance along the axes of the columns. After gaining 75% of the design strength with a solution, the cable reinforcement is pretensioned in two mutually perpendicular planes. After that, the channels of the columns are injected with a cement-sand mortar together with cable reinforcement, after gaining 75% of the design strength of which, this reinforcement is pulled down. Then, the contact seams with cable reinforcement are monolithic. Thus, one disk of floor slabs is mounted. In a similar way, the following disks of floor slabs are sequentially mounted one above the other, but before tensioning each lower disk of floor slabs, the upper disk is mounted and contact joints are embedded in it between the grooves of the floor slabs and the faces of the columns and between the floor slabs, after gaining 75% of the design strength of the solution in these seams, the reinforcement of the lower disk of the floor slabs is pre-tensioned, followed by pulling the reinforcement down and further embedding the contact joints. At the same time, preparatory work is carried out for the installation of the next disk of floor slabs, laying out another set of installation devices and simultaneously delivering building materials for the construction of walls and internal partitions of the building. In this way, floor slab discs are mounted 3 floors ahead of masonry walls.

Characteristics:

Displacement of columns from the design position when the lower disk of floor slabs is tensioned, no more than ± 5%;

Advancing the construction of a frame cell in comparison with the laying of walls and internal partitions, the number of floors is 3;

There are no additional devices for fixing columns that prevent their displacement from the design position.

The claimed method of erecting buildings and structures with a beamless frame is high-tech, reduces the construction time of buildings, ensures the elimination of technological interruptions and allows the erection of disks of floor slabs ahead of them by 3 floors compared to the erection of walls and internal partitions of a building with the possibility of preliminary delivery of building materials to the erected disk floor slabs before subsequent installation by successive installation of subsequent upper disks of floor slabs together with the laying of a cement-sand mortar in the contact joints between the grooves of the floor slabs and the faces of the columns and the seams between the floor slabs until pre-tensioning each lower disk of the floor slabs.

Fixation of the columns by the claimed method allows to ensure the equality of the gaps between the faces of the columns and the grooves of floor slabs, balcony slabs, side beams with a deviation of not more than ± 5% without the use of special equipment and devices, which increases the strength of the building structure and the safety of its operation, all this ultimately significantly reduces the cost of building construction.

A method for erecting a girderless frame, including sequential prestressing of the floor of each floor by connecting adjacent columns with floor slabs by means of reinforcement stressed during installation, characterized in that before tensioning each lower disk of the floor slabs, columns are installed together with technological equipment for mounting the upper disk on these columns floor slabs, while racks are mounted under the floor slabs, they are leveled together with mounting tables on columns, then plywood strips are laid on these tables and racks and floor slabs, side beams, balcony slabs are mounted, then cement-sand mortar is laid in the seams between the grooves of the floor slabs and the faces of the columns and into the seams between the floor slabs, after gaining a solution of 75% of the design strength, the lower disk of the floor slabs is pre-tensioned, excluding the displacement of the columns from the design position, while the installation of floor slabs, side beams, balcony slabs is carried out as follows, so that the gap between the grooves of the floor slabs, balcony slabs, side beams and the faces of the columns is 2-3 cm, and at the same time, the reinforcement is prepared along the length to tension the lower disk of the floor slabs by measuring the distance along the axes of the columns after mounting the upper disk of the floor slabs.

DESCRIPTION OF THE SYSTEM ACCORDING TO THE INFORMATION OF SPA "KUB"

KUB-2.5 structures are designed for the construction of buildings up to 25 floors and above in I-IV climatic regions, both under normal conditions and under conditions of increased seismic activity up to 8 points. It is also possible that the construction of buildings up to 16 floors high and in areas with seismicity up to 9 points.
The frame is easy to manufacture and install. Frame products have a simple geometric shape and have a limited number of standard sizes, which greatly facilitates its development. The fleet of forms is minimal, the forms themselves are simple and adaptable.
Frameless frame elements can be easily manufactured in newly developed areas, in the absence of an industrial base, as well as in places where the production of existing series frames has not yet been established. The crossbar frame has architectural, planning and design advantages over traditional block frames.
A smooth floor ceiling in some cases makes it possible to abandon expensive false ceilings, which are necessary for hygienic, aesthetic or technical requirements.
The reduced building envelope of the ceiling makes it possible to reduce the cubic capacity of the building by 5-8%. The presence of a cantilevered part along the perimeter of the floor allows you to conveniently solve the temperature-sedimentary seams, adjoining to other buildings, the installation of galleries and sun protection elements for the southern regions.

One of the advantages of the frame is the reduced consumption of steel and cement per 1 sq.m of flooring compared to frame systems used both domestically and abroad.
Another advantage is the ease of installation.
The shaping capabilities of the frame have a wide range from one-story to multi-story buildings with a complex architectural and spatial solution.
Experimental and theoretical studies carried out at the TsNIIEP Institute of Housing confirmed the rigidity and strength qualities of the structure, as well as the reliability of the calculated assumptions.

The girderless frame consists of square columns and flat floor panels. Floor panels have dimensions in terms of 2.98x2.98 m, so the gap between them is only 20 mm and this makes it possible to seal the joints without installing formwork.
The thickness of the panels is 160 mm.
The system provides for two-module panels obtained by combining two adjacent panels:
1. Above-column and annular.
2. Intercolumn and middle.

This allows you to speed up installation in two and save on the monolithic joints.
Floor panels, depending on their location in the plan, are divided into above-column, inter-column and inserts. 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 spatial rigidity of the structure is ensured by a monolithic connection of elements (floors and columns) and, if necessary, by the inclusion of connections and diaphragms in the system.

After installing the reinforcement in the joints between the panels, the joints are monolithic, at the same time the joints of the above-column slabs with the columns are monolithic along the entire ceiling at this level.

The seams between the plates are used to pass engineering communications.

Frame structures are designed for the construction of buildings according to a frame or frame-braced scheme.

The number of floors according to the frame scheme is limited to 5 floors, according to the frame-braced scheme it is practically unlimited, provided that the strength qualities of the columns are ensured by increasing the percentage of reinforcement for the introduction of rigid reinforcement.

The joints of the frame elements are monolithic, forming a frame structural system, the crossbars of which are the ceilings.

Installation of multi-storey frame frames is carried out using simple fixtures. Mobile or tower cranes with a lifting capacity of 5 tons and more are used as lifting equipment.

The installation of structures is carried out in the following order: columns are mounted and embedded in the foundation glasses, over-column panels are installed and welded to the reinforcement of the columns, then inter-column panels and insert panels are mounted.

The range of products provided for in the KUB-2.5 releases allows designing buildings with spans of 6 and 3 m with a column spacing of 6 and 3 m, floor heights of 2.8; 3.0; 3.3 m. Frame constructions involve the use of external internal walls both from piece material and in the form of large-sized elements - panels.

External wall panels are designed as single-layer expanded clay concrete of vertical cutting.
Builders note the convenience of mounting the frame, the ease of its development at the construction site, the possibility of achieving high labor productivity.

The main architectural disadvantage of frame systems for their use in civil engineering is the crossbars protruding into the interior from the plane of the ceilings. There are structural schemes of frames to eliminate this drawback:

A system formed from prefabricated solid-section slabs supported on columns at the corner points of the grid of columns (KUB system);
Frame system with prestressed reinforcement in hidden crossbars formed in construction conditions (KPNS system).

The KUB frameless frame system (Fig. 16. 6) is a prefabricated frameless frame consisting of square columns and flat floor slabs.

Grids of columns 6x3 and 6x6 meters, if necessary, can be increased to sizes of 6x9 and 9x12 meters. The section of the columns is 30x30 cm and 40x40 cm, one or more floors high, with a maximum height of up to 15.3 m.

Floor slabs in terms of size 2.8x2.8 m, thickness from 16 to 20 cm. Depending on the location, they are divided into: - above-column, inter-column and slabs - inserts. The division of the floor into prefabricated elements is done in such a way that the joints of the plates are located in zones with the smallest value (approaching zero) of bending moments from vertical loads.

The sequence of installation of the ceiling on the mounted columns is carried out in the following order: - over-column plates are installed and welded to the reinforcement of the columns, then inter-column plates and, finally, insert plates. Intercolumn and insert plates have dowels, which make it easy to weld them together. After monolithic joints, a spatial rigid structure is created.

The advantage of the system is the absence of protruding elements in the ceiling plane and ease of installation using light mobile cranes.

A girderless frame or frame-and-braced frame system of civil buildings up to 16 floors high is designed for vertical floor loads of 1250 kg/m 2 . At heavy loads (2000 kg / m 2), the number of storeys of the building is limited to 9 floors.

The system has architectural, planning and design advantages. A smooth ceiling makes it possible to flexibly decide the layout of the interior space to create transformable rooms. Cantilever overhangs of floors provide variability of plastic solutions for facades.

The crossbar frame is universal - it is successfully used both in residential buildings and public (kindergartens, schools, trade enterprises, sports and entertainment) facilities, etc.

The system with hidden crossbars in the floor plane (KPNS) is designed according to the connection scheme of prefabricated elements; columns, slabs, ceilings and walls of stiffening diaphragms. The connection between the prefabricated floor elements is carried out as a result of the construction of a monolithic crossbar with cable stressed reinforcement passed through the through holes in the column in orthogonal directions under construction conditions. The prestressing of the reinforcement is carried out at the level of floor slabs, creating a biaxial compression of the floor slabs (Fig. 16.7).

The floor slabs are 30 cm high and consist of a top slab 6 cm thick and a bottom slab 3 cm thick and crossed side ribs. During installation, floor slabs are laid on temporary capitals of columns and supports, which are already installed on the mounted lower level. Floor slabs can be made into a cell supported by columns at 4 corners or divided into two slabs connected by a monolithic reinforced seam. The structure, assembled from prefabricated elements of columns and floor slabs, works as a single static system that perceives all force effects due to the cohesive forces that arise between individual prefabricated elements and the stresses of steel ropes.