WO2013187803A2

WO2013187803A2 - Method for increasing the load-bearing capacity of a girderless monolithic reinforced-concrete framework

Info

Publication number: WO2013187803A2
Application number: PCT/RU2013/000464
Authority: WO
Inventors: Сергей Геннадьевич КУЗЬМЕНКО
Original assignee: Kuzmenko Sergey Gennadievich
Priority date: 2012-06-14
Filing date: 2013-06-06
Publication date: 2013-12-19
Also published as: WO2013187803A3; RU2490403C1

Abstract

The technical effect consists in increasing the load-bearing capacity of a framework in the construction of residential, public-use and industrial buildings, inter alia those with floor spans exceeding nine meters, without the pre-stressing of rebars, with various types of column cross-sections, and in tall monolithic construction, including in areas of heightened seismic activity, by means of redistributing the forces at the interfaces between columns and floors, creating individual structural element nodes, conditionally limited, horizontally, to lines of calculated zero bending moments in the floors around the columns, and vertically, to column cross-sections located in the middle of the vertical distance between floors; by including element nodes, an eccentricity is created in the transfer of vertical load to the columns; a framework is formed using individual structural element nodes, said nodes being united by rebar into a spacial framework, said rebar being continuous and, in the radial direction, annularly fastened across adjacent floors and columns.

Description

A method of increasing the bearing capacity of a bezelless monolithic ^ reinforced concrete frame

A method of increasing the bearing capacity of a bezelless monolithic reinforced concrete frame relates to the field of construction, and can be used in the construction of housing, cultural, domestic and industrial facilities, including with spans of floors of more than 9 meters, with various types of column sections, in high-rise monolithic construction, including in areas with increased seismic activity.

Known are traditional methods of assembling reinforced concrete bezelless frames from columns and flat floors, at the intersection of which, as a rule, the reinforcement of the columns is not connected with the reinforcement of the floor. As a result, in order to increase the load-bearing capacity of the carcass, when the load is perceived, with an increase in the size of the span, the thickness of the slab and / or the cross-section of the column is increased, as well as densely reinforced near-column zone of overlap.

It is known that during concreting, as a rule, the joints are located at the level of the upper and lower planes of the floor slab, that is, the plates intersect with the concreting of the column.

It is known that the joint of the longitudinal reinforcement of the columns is carried out mainly with an overlap in the body of the column, which leads to a useless overspending of the reinforcement, especially with an increase in the diameter of the reinforcement.

If, with the traditional reinforcement system, with increasing column spacing and floor loads, with a column cross-section of 400x400 and a plate thickness of 200 mm, as a result of the calculation, we obtain the calculated reinforcement in the upper stretched zone of the floor slab: Ah + Au ^ 100cm ² , where Ah, Au - calculated value of reinforcement in mutually perpendicular directions, it is simply impossible to place such a quantity of reinforcement in the stretched zone of the plate.

The well-known "Method of erecting a frame of a bezelless multi-storey building" according to the patent RU 2134752 from 01/21/1998, published on 08/20/1999,

MPK ° E04V1 / 18, which consists in the installation of ordinary and external columns, the installation of supercolumn floor slabs on them, and the installation of intercolumn and central floor slabs, in this case, after installing the ceiling of the upper floor of the building on the upper floor or on the upper floors, diagonal struts are additionally mounted connecting the bottom of the outer columns with the top of the adjacent row columns or the top of the outer columns with the bottom of the neighboring row columns within each of these floors and located normally to the building facade corresponding to them, and then part of the outer columns placed under the diagonal struts within the first floor is removed.

This method is difficult to use due to additional struts, and does not allow to erect buildings with large spans of floors.

The well-known "Method of erecting a bezelless building frame" according to patent RU 2206674 from 1 October 1, 2001, published June 20, 2003, IPC 7 Е04В1 / 18, Е04В1 / 22, including installation of columns and floor slabs, monoling joints between columns and slabs, passing valves through columns between slabs in mutually perpendicular directions and tension, holding until the joint between the columns and slabs of transmission strength is set by concrete with subsequent transfer of tensile forces to concrete along the perimeter of the building and monolithic joints between the slabs, and after concrete is set m joint between the columns and slabs transfer strength, tensile force on the concrete reinforcement is transmitted alternately in mutually perpendicular directions in stages - first 30-40% of the tensile force, then 60-75% of the total tensile force from the subsequent complete release of tension.

This method is also difficult to use due to the fact that it requires additional tension of the reinforcement on concrete, and there is no constructive connection of the columns with the ceiling.

The closest is the "Method of increasing the bearing capacity of bezbolnogo monolithic reinforced concrete floors" according to patent RU 2394140, from 09.06.2009, published 10.07.2010. IPC E04G23 / 02, E04B5 / 43, including placement on the floor slab connected to the column, which is provided with longitudinal reinforcement of reinforcing elements, while vertical holes are made in the near-side zone of the floor slab in which reinforcing elements are installed in in the form of a set of rods with anchor elements at the ends, forming transverse reinforcement not connected with the longitudinal reinforcement, and fill the solution with a non-shrink expanding concrete mixture; the near-wall zone of overlapping of the vertical rods of the transverse reinforcement in the plan has the shape of four rectangles, one side of each of which adjoins the column and is equal to the width of the latter, and the other side exceeds 1.5-3.5 times the thickness of the floor slab; the diameter of the holes made in the floor slab is 1, 5 ^ -2.5 times the diameter of the rods of the transverse reinforcement, while the holes on the bottom are made blind with a bottom or equipped with a stopper; the near-column zone of overlapping the placement of vertical rods of the transverse reinforcement in the plan has the shape of a square described around the column, the side of which is equal to the sum of the column width and twice the determining size of the near-column zone - the distance between the external boundary of the near-column zone and the column exceeding 1.5, 5, 5 times the thickness floor slabs.

This method of increasing the bearing capacity of a bezel-free monolithic reinforced concrete floor reinforces only the near-column part of the floor and only additional transverse reinforcement, without creating a single node for connecting the column to the floor.

The objective of the proposed technical solution is to provide increased load-bearing capacity of a monolithic reinforced concrete frame during the construction of housing, cultural, domestic and industrial facilities, including with spans of floors of more than 9 meters, without prestressing reinforcement, with various types of cross-sections of columns, in a monolithic high-rise construction, including in areas with increased seismic activity.

The problem is solved by a method of increasing the bearing capacity of a bezelless monolithic reinforced concrete frame, including connecting columns with floor slabs, and the placement of reinforcing elements, while increasing the carrying capacity of the frame by redistributing the forces at the places where the columns are joined with the floors, creating single structural units, the conditional boundaries of which are, on the plan, the lines of the calculated zero bending moments in the ceilings around the columns, and the vertical sections of the columns located in the middle of the height of the floors; the design of the element-unit sets the eccentricity of the vertical load transfer to the columns; they form a frame from unified structural element-nodes, combining them into a spatial frame continuous and looped in radial directions, through adjacent ceilings and columns, by reinforcement.

A method of increasing the bearing capacity of a bezrigelny monolithic reinforced concrete frame, by redistributing the forces at the mating places of the columns with the ceilings, allows to increase the resistance to mutual rotation of the columns and ceilings at the mating places, and to increase the rigidity of the frame in all directions; increase resistance to horizontal loads, such as wind and ripple; adjustable eccentricity "e" to start the mechanism of automatic unloading of columns; to perceive bending moments from wind and flying loads as a single unit-node with a height of the whole floor, and not separately by a column and ceiling; redistribute the force of pushing the ceiling over the column, since the ceiling does not feel support on the column, but on a significantly expanded area, due to the special configuration of the reinforcing bars in it, since the bends of the longitudinal reinforcement of the lower column, resting against the bends of the longitudinal reinforcement of the upper column, create the effect of supporting capitals in the body of the plate, at the same time, being reliable anchors in the perception of bending, pinned moments; increase the seismic resistance of the frame.

A method of increasing the bearing capacity of a bezelless monolithic reinforced concrete frame is carried out in the frame shown in the drawings, where in Fig. 1 is the frame assembly, in Fig. 2 is a monolithic structural unit with reinforcement 9, in Fig. 3 - reinforcement 9, 17, 18; in FIG. 4 is a structural section through the frame, in FIG. 5 - layout of the reinforcement in terms of overlap, in Fig.6 a monolithic structural unit with reinforcement 18, in Fig.7 - arrangement of equidistant columns according to the principle of an equilateral triangle.

In FIG. 1, 2, 3, 4, 5, 6, 7: frame 1 monolithic reinforced concrete bezelless assembly, rigid structural unit-node 2, column 3, floor 4, line 5 of the calculated zero bending moments in the floors, section 6 columns with the smallest bending moments location of concreting joints, reinforcing 7 radial floors, reinforcing 8 concentric, longitudinal reinforcement 9 of the column part of the assembly with bends in the plate part of the assembly, elongated near-edge zone 10 of the tile part of the assembly, zone 1 1 of the ceiling slab, extended flight, reinforcement 12 structural, joint 13 bent parts of the longitudinal reinforcement of the column part of the element-node in the upper stretched near-slab plate part of the element-node, cantilever overhangs 14 of the ceiling, annular distribution reinforcement 15, eccentricity "e" 16 gear Loading the overlap on the column longitudinal reinforcement 17 with the pillar portion of the assembly in limb portion of plate assembly, the longitudinal reinforcement 18 with the pillar portion of the assembly in limb portion of plate assembly pillar portion 19-node element of plate portion 20-node element.

A method of increasing the bearing capacity of bezrigelnogo monolithic reinforced concrete frame is carried out during its assembly as follows.

Install the formwork of the floor 4 of the current floor. Under this formwork, sections of the castle formwork are installed on the upper part of the columns, from section 6 of the current floor.

A structurally organized element-node 2 is formed from the column part 19 and the plate part 20, around the center located at the intersection of the central axis of the column 3 with the floor slab 4, vertically - from the half of the column of the current floor and half of the column of the next floor, with conditional boundaries along the section of 6 columns located in the middle of the height of the floors, and on the plan - from a fragment of the overlap around the columns, with conditional boundaries along the line of 5 calculated zero bending moments in the floors, matching the plate and column parts, combined radially directed longitudinal reinforcement of 9, or 17, or 18 columns, with bends to the plate part of the assembly element, while creating conditions for the redistribution of forces in the places of conjugation of columns with ceilings, increasing the bearing capacity of the frame.

Reinforcement, with a special configuration of bends ^ 9, ^ 3 17, ^ 18, is the main generatrix of the reinforcing cage of the element-node 2.

In the stretched near-zone zone 10 of the slab part of the element-node 2, the reinforcement 9 and / or 17 and / or 18, with bends for the lower and upper floors, are rigidly connected to the vertical overlap. The presence of reinforcement 9, 17, 18, bends in the upper elongated near-zone zone 10 of the slab part of the element-node 2, defines, always present and regulated by design solutions, the eccentricity "e" 16, the transmission of the vertical load of the ceiling to the column.

The presence of eccentricity "C" 16 transfer of vertical load to the column part 3 of the element-node 2, with a rigid joint 13 and the curved shape of the part 9 or 17 or 18:

- creates a moment in the columned part of the reinforcement 9 or 17 or 18, pushing the reinforcement up, that is, in the reinforcement 9 or 17 or 18 an unloading column 3 creates an upward force;

- provides automatic operation of the unloading mechanism: with an increase in the number of floors, the unloading moment in the columns of 3 underlying floors also increases.

The assembled spatial reinforcing cage for forming the element-node 2 is set with its bends of the reinforcement 9, and / or 17, and / or 18, on the same spatial reinforcing cage protruding from the column 3 of the current floor, on the bends of the reinforcement 9, and / or 17, and / or 18,

Bends of the longitudinal reinforcement 9, or 17, or 18, of the lower column (FIG. 2, FIG. 4, FIG. 6), abutting against the limb of the longitudinal reinforcement 9 or 17 or 18 of the upper column (FIG. 2, FIG. 4, FIG. 6) create the effect of supporting capitals in the body of the plate, at the same time being reliable anchors in the perception of bending near-face moments. At the same time, the overlap during operation does not feel support on the column, but on a significantly expanded area.

Bends are welded in the overlap of reinforcement 9, and / or 17, and / or 18, of the current and next floor. Next, radial reinforcement 7 is laid out, welding it with reinforcement 9, or 17, or 18, (Fig. 2), concentric reinforcement 8 is installed in the span of the ceiling (Fig. 2, Fig. 6), and structural reinforcement 12, that is, form a frame from unified structural elements-nodes, combining them into a spatial framework continuous and looped in radial directions, through adjacent floors and columns, by reinforcement, creating a continuous column-ceiling-column-ceiling system, looped by adjacent ceilings and columns of radial reinforcement m (see FIG. 4)

Then install the formwork sections of columns 3 in half the next floor and concreting the ceiling 4 of the current floor with half of the column 3 of the current floor and half of the column 3 of the next floor, that is, the elements-nodes 2 are concreted entirely in one grip between, located in the middle of the height of the floors, sections 6 columns 3, which dramatically increases the bearing capacity of the frame .

The bearing capacity of bezrigelnogo monolithic reinforced concrete frame increases with the operation of the element-node 2, as follows.

The main characteristic of the element-node 2 is the eccentricity "e" 16 transfer load overlap on the column.

Span vertical loads acting on the overlap are transmitted through reinforcement 9 or 17 or 18 to column 3 with an eccentricity "e" 16. Moreover, on each floor in the longitudinal reinforcement of the columns, in addition to the compression force N, tensile forces arise from a bending moment equal to M = Nc. (Fig. 4)

Due to the presence of eccentricity 16 and continuity, ringing with the adjacent floor) of radial reinforcement, column-overlap-column-overlap, (Fig. 4) span loads on the ceiling stretch the radial reinforcement, including in the column zone, creating a discharge moment in the reinforcement the columns. Given this, you can reduce the cost of reinforcing columns.

Moreover, with the same parameters of the floors and loads and eccentricities, compression forces ΣΝ = ηΝ and a bending moment M = nNe, where η is the number of floors, will arise in the reinforcement of the columns of the lower floor.

If, in the traditional method of assembling the frame, the bending moment above the column did only destructive work, then in the proposed technical solution, the bending moment M created by the eccentricity "e", due to the special shape of the reinforcement 9 or 17 or 18, tends to pull the reinforcement up, that is, it creates vertical force directed upward, and opposite to the vertical load on the frame.

Due to this, the self-unloading effect in the columns constantly works in the frame, and with the increase in the number of floors, the unloading effect also automatically increases in the lower floors.

Due to the vertical overlap of the bends of the longitudinal reinforcement 9, or 17, or 18, columns 3, in the stretched near-zone zone 10 of the slab part element-node 2, creates additional rigidity of the cross section of the reinforcement during the perception of bending moment (Fig. 4).

Due to the rigid joint of 13 bends of the longitudinal reinforcement of the columns and its further branching into columns of the upper and lower floors, the resistance to bending moment in the direction from the joint increases

13 to the column 3, due to the increase in the distance between the sections of the bends 9 of the upper and lower columns.

A method of increasing the bearing capacity of a bezrigelny monolithic reinforced concrete frame by redistributing the forces in the places of conjugation of columns with ceilings allows:

- increase the resistance to mutual rotation of the elements (columns and ceilings) in the interface and increase the rigidity of the frame in all directions;

increase resistance to horizontal loads (wind, wind ripple);

adjustable eccentricity "e" to start the mechanism of automatic unloading of columns;

- redistribute the bending moments of the ceilings, which are no longer perceived by the column, but by the element-node, and redistribute the force of forcing the overlap over the column, since the overlap feels support not on the column, but on a significantly expanded area, due to the special configuration of the reinforcing bars in it, since bends of the longitudinal reinforcement of the lower column (FIG. 2, FIG. 4, FIG. 6), abutting against the bends of the longitudinal reinforcement of the upper column (FIG. 2, FIG. 4, FIG. 6) create the effect of supporting capitals in the body of the plate, at the same time being reliable mi anchors in the perception of bending funnel moments.

The technical effect is to provide increased bearing capacity of a monolithic reinforced concrete frame during the construction of housing, cultural and domestic and industrial facilities, including with spans of floors of more than 9 meters, without prestressing reinforcement, with various types of cross-sections of columns, in high-rise monolithic construction, including in areas with increased seismic activity, by redistributing efforts in the places where the columns are interfaced with overlappings, creating uniform structural elements-nodes, conditional the boundaries of which are, on the plan - lines of calculated zero bending moments in the ceilings around the columns, and vertically - sections of columns located in the middle of the height of the floors; the design of the element-unit sets the eccentricity of the vertical load transfer to the columns; they form a frame from unified structural elements-units, combining them into a spatial frame continuous and looped in radial directions, through adjacent ceilings and columns, by reinforcement.

Claims

Formula

A method of increasing the bearing capacity of a bezelless monolithic reinforced concrete frame, including connecting columns with floor slabs, and placing reinforcing elements, characterized in that the load-bearing capacity of the frame is increased by redistributing the forces at the places where the columns mate with the floors, creating uniform structural units, conditional boundaries which are, on the plan - lines of calculated zero bending moments in the ceilings around the columns, and vertically - sections of the columns located in the middle of the floors; the design of the element-unit sets the eccentricity of the vertical load transfer to the columns; they form a frame from unified structural elements-units, combining them into a spatial frame continuous and looped in radial directions, through adjacent ceilings and columns, by reinforcement.

SUBSTITUTE SHEET (RULE 26)