EA010211B1 - A reinforced concrete column with reinforcing steel pipes - Google Patents

Abstract

The invention relates to building, particularly to the structural elements of the frames of multistory buildings and constructions on which high demands for increased bearing capacity and reliability are made.A reinforced concrete column with reinforcing steel pipes includes the steel pipe 1 (fig. 3), which hollow is filled with concrete 2. The transversal rods 3 are located in concrete 2 in the sections of the column at its vertical line. Said rods form the grid with the cells 4 in each plane. The rods 3 at the ends are fixed in the steel side of the pipe and/or in the steel patch pieces 6. The packets 7 in the form of the tightly placed groups of the rods of longitudinal reinforcement are located and by means the grids of the transversal rods 3 in the cells 4 are fixed along the column in concrete 2.Increasing bearing capacity and reliability of the reinforced concrete column with reinforcing steel pipes are provided by increasing stability of longitudinal reinforcement due to concentrated placing its rods in the form of the packets 7, and also by increasing stability of the sides 1 of the pipe owing to placing in concrete 2 transversal reinforcement 3 fixed at the ends by the anchors 5 in the steel flat pieces 6 located outside along the perimeter of the section of the pipe. The reinforced concrete column with reinforcing steel pipes can have a cylindrical or prismatic shape. The invention provides increasing bearing capacity and reliability of the reinforced concrete column with reinforcing steel pipes.

Description

The invention relates to the construction, in particular, to the structural elements of the frames of high-rise buildings and structures, to which the requirements of increased bearing capacity and reliability.

Known assembled pipe-concrete column, comprising a concrete core and a steel tubular holder, covered with a lubricant inside, preventing its adhesion to concrete [1]. The famous column has a high carrying capacity.

A disadvantage of the known column is the complication of technology, as well as the need for special lubricants that do not change their properties over time.

Famous column - a building element, working in compression, including a tubular holder, made of oriented fiberglass and filled with concrete on expanding concrete [2].

The known column has a high durability and works elastically under load.

A disadvantage of the known columns is the relatively low bearing capacity and the presence of significant longitudinal deformability under load.

Famous column, comprising a metal pipe filled with a concrete core containing a spiral reinforcement [3].

The known column has a high bearing capacity if the required accuracy of installation and fixation of the spiral reinforcement in the concrete core is ensured.

A disadvantage of the known column is the lack of reliability in terms of its carrying capacity due to the uncertainty of fixing the spiral reinforcement.

Closest to the proposed steel-concrete column is a column comprising a metal pipe filled with concrete containing longitudinal rod reinforcement [4].

Known technical solution performs the task of increasing the carrying capacity, however, not fully. Rods of longitudinal reinforcement uniformly distributed around the perimeter are ineffective in the use of their strength properties due to their considerable flexibility and loss of stability under compression. This is especially noticeable when an eccentric longitudinal force is applied, when bending moments appear in the plane of the column sections. The lateral deformations of the concrete core of the column contribute to the loss of local stability of the pipe wall with its longitudinal compression even at a relatively low level of loading. All this can lead to incomplete use of the strength properties of reinforcement and concrete and a decrease in the reliability and carrying capacity of the column.

The technical result of the invention is to increase the carrying capacity and reliability of steel-concrete columns.

This technical result is achieved by the fact that in a steel concrete column comprising a metal pipe filled with concrete, forming in the pipe cavity a reinforced concrete core containing longitudinal bar reinforcement in the reinforced concrete core along the height of the column in a mutually perpendicular direction along the main axes of the cross section of the column throughout width placed transverse rods with the formation in each plane of the lattice and fixing them at the ends in the steel wall of the pipe, the rods of the longitudinal reinforcement reinforced The cores are combined into packages in the form of a group of rods, each package around its perimeter is covered with clamps or rewinding of reinforcing wire, and packages of rods of longitudinal reinforcement are placed in grid cells formed by transverse rods.

A steel column can be cylindrical in shape and may contain discrete steel lining at discrete locations where the transverse rods are fixed.

A steel column can be made in the form of a prismatic rod of rectangular cross section and contain solid steel strip plates on the side faces, in which transverse rods are fixed by ends.

The grids formed in the steel-concrete column by transverse rods are placed in the cross-sections of the column with a height increment of not more than 0.5 b, where b is the size of the cross-sections of the column along its smallest side.

Comparison of the proposed technical solution with the prototype makes it possible to note that it differs from the well-known new features (1) in the concrete core in the height of the column in mutually perpendicular directions along the main axes of the cross-section of the column; across its width are transverse rods with (2) formation in each lattice planes and (3) with fastening them at the ends in the steel walls of the pipe, (4) the bars of the longitudinal reinforcement are combined into packages as a group of closely spaced rods, and each package along its perimeter Packages of longitudinal reinforcement rods are placed in clamps or windings of reinforcing wire, and (5) in the cells of the grids formed by transverse rods. (6) The column is cylindrical in shape and contains discrete steel strip plates at the fixing points of the transverse rods. (7) The column is made in the form of a prismatic rod of rectangular and cross-section and contains on the side faces steel strip lining in the form of solid bands in which the transverse rods are fixed. (8) Lattices formed by transverse rods are placed in cross sections of a column with a step along its height of not more than 0.5 b, where b is the cross-sectional size of the column at the smallest

- 1 010211 to its side.

All the listed signs allow to realize the proposed column of increased bearing capacity and reliability, due to the precise inclusion of all elements of the steel-concrete column under work, ensuring the fullest use of the strength properties of the reinforcement, concrete and steel pipe.

All the listed features of the proposed technical solution in the above amount are not known, and the technical result achieved by the proposed solution exceeds the known ones, allowing you to completely solve the task, and creates a super-total result due to the mutual reinforcement of each feature on each other in their accepted combination.

The essence of the proposed technical solution is illustrated by drawings.

FIG. 1 shows the nature of the deformation and fracture of a fragment of a steel-concrete column under longitudinal compression;

in fig. 2 - a fragment of the proposed steel concrete column with transverse rods, anchored in steel strip plates placed on the outer surface of the pipe, side view;

in fig. 3 - the same, a fragment of a steel-concrete column with transverse rods and rods of longitudinal reinforcement, combined in packages;

in fig. 4 is the same, the cross-section A-A in FIG. 2 steel columns of cylindrical shape;

in fig. 5 is the same, the cross-section A-A in FIG. 2 columns of rectangular cross section;

in fig. 6 is the same cross-section BB in FIG. 3 cylindrical columns with packages of densely arranged longitudinal rods in the cells of the lattice formed by transverse rods;

in fig. 7 is the same, cross-section BB in FIG. 3 in the case of a rectangular column.

The proposed steel concrete column (Fig. 2-7) includes a steel pipe of rectangular or circular cross section with walls 1, the cavity of which is filled with concrete 2. In concrete 2 in cross sections of the column along its height there are transverse rods 3 forming a grid with cells 4 in each plane. The rods 3 at the ends are fixed with anchors 5 in the walls of the pipe and / or steel strip plates 6. The plates along the outer perimeter of the column section can be made as a continuous strip or discretely only under the anchors 5. The choice of the type of lining 6 is performed Depending on the wall thickness of the tube 1 and the cross-sectional dimensions of the column, and the longitudinal force acting at these sections. In concrete 2 along the column are placed, and by means of gratings of transverse rods 3, packages 7 are fixed in their cells 4 in the form of densely arranged rods of longitudinal reinforcement. Packages 7 can be placed in the most advantageous position for receiving external efforts in cells 4 that are adequate to their action in the cross section of the column. Concrete 2 together with the transverse rods 3 and the longitudinal reinforcement in the form of packages 7 form the reinforced concrete core of the column. Through the release of packages 7 at the ends of the columns can be provided for a rigid Association of the column with overlapping. The docking of the columns can be carried out in the levels of overlap with the docking or overlapping packages of 7 adjacent columns in height. In this case, flanged or other pipe connections of 1 adjacent columns are not required.

Under the action of the longitudinal force N on the column in analogues [1-3] and prototype [4], their destruction is accompanied by the development of transverse deformations of concrete 2 with the formation of local buckling 8 of the pipe wall 1 along a series of cross sections of the column (Fig. 1). The high bearing capacity of the concrete core 2 of the column is achieved due to the presence of reactive lateral pressure arising on the inner surface of the pipe during transverse deformations of the concrete core 2. After the wall 1 of the pipe 1 is exhausted, the resistance of the core 2 is further increased due to its bulging 8 and loss of stability occurs exhaustion of the carrying capacity of the entire column. Therefore, in order to further increase the bearing capacity of the column, in addition to the concentrated placement in the longitudinal reinforcement packages 7, it is necessary to prevent the loss of stability of the wall of the pipe 1. To increase the stability of the wall of pipe 1, transverse rods 3 are mounted in the column, fixed with anchors 5 in steel strip lining 6. They prevent local bulging of the 8 walls of the pipe 1 (see Fig. 1) and the fall due to this value of lateral pressure. Cross placement of transverse rods 3 approximately uniformly across the width of the column section allows forming cells 4 in each plane of their placement in which the required longitudinal reinforcement in the form of packages 7 of tightly laid reinforcing rods with increased rigidity for longitudinal bending can be placed in fixation, compared to the same number of detached rods. As a result, the carrying capacity of the proposed column in comparison with analogues [2, 3] will increase by 4-5 times and 1.3-1.5 times in comparison with the prototype [4] with the same longitudinal reinforcement.

The fixed position of the transverse rods 3 and the longitudinal packages 7 of reinforcement rods, combined by clamps (not indicated), can significantly improve the reliability of the proposed steel-concrete column, since the reactive lateral pressure on the concrete along the surface of the pipe 2 remains at higher levels of load application. This pressure not only delayed

- 2 010211 formation of longitudinal cracks in concrete 2 of the column core, but also hinders their development. In order to obtain columns with a particularly high bearing capacity, in this case, concretes of usual traditional strength equal to 30–40 MPa can be used. If there are eccentricities in the column, the packages 7 of the longitudinal reinforcement are placed in the cells 4 in accordance with the existing efforts. The placement of the transverse gratings formed by the rods 3, with a pitch of the column height of not more than 0.5 b, where b is the smaller cross-sectional size of the column, helps prevent the pipe wall 1 from bulging and thereby ensure the most uniform lateral resistance of wall 1 to concrete 2 over the entire height of the column. Increasing the pitch of the gratings of the rods 3 over 0.5 b decreases their effectiveness, since the bulging 8 of the wall 1 can occur in the column sections between the gratings formed by the rods 3, and lead to an earlier exhaustion of the bearing capacity of the column with the under-utilization of the strength properties of the rods 3, walls 1 pipe and concrete 2.

If a longitudinal tensile force appears in the column sections, which may occur, for example, with increased horizontal loads on the building, as well as unauthorized and accidental impacts on the frame, through the longitudinal axis can be placed in the column along the longitudinal axis the height of the building armature 9, landed at the ends in the foundation structure and the floor of the building. This reinforcement 9, under normal loading conditions of the column, together with concrete 3, packages 7 and the pipe wall 1, perceives longitudinal compressive forces при, and at the indicated change in loading conditions it should be able to absorb tensile forces.

With the most common cross-sectional dimensions within 50-60 cm, the column can be made in a horizontal position, having previously fixed transverse rods 3 on the tube 1, placing and fixing the packages 7 of the longitudinal reinforcement in the tube cavity. The flow of concrete mix can be accomplished by shutting down one end of the pipe, pumping the mixture through the other end into the pipe cavity with a concrete pump until the end of its filling. The control of the complete air outlet and the filling of the cavity of the pipe 1 with the mixture is carried out through a viewing hatch 10 in the pipe from the back side of the injection site to the displacement of a part of the mixture on the outer surface of the pipe. Then the inspection hatch 10 is cleaned of excess solution and closed with a valve. After a set of concrete 2 of the required strength of the finished column is mounted in the design position and monolithic in the bearing frame.

For large cross sections of the column, it is manufactured locally in the frame. In this case, the pipe 1 is also used as a formwork, but is installed in a vertical design position with reinforcement 3, 7 and 9 placed and fixed in the cavity. The concrete mix is supplied with a concrete pump through the hatches 10 in pipe 1, starting from the bottom, rising upwards as it is filled cavity pipe 1 concrete mix. Through these hatches 10, the filling of the pipe 1 with the mixture is monitored.

In general, this allows us to note that with the implementation of the features indicated in the present invention in comparison with analogues and prototype [4], a new quality of a steel-concrete column was obtained, which is expressed in increasing reliability and carrying capacity.

The proposed technical solution will be applied and most appropriate for buildings and structures with particularly high loads on the columns.

Information sources

1. VNIIIS Gosstroy USSR. Construction and architecture. Series 8. Building structures and materials. Express information, pipe-concrete columns without adhesion of concrete with a steel ferrule. M .: VNIIIS, 1986, vol. 17, p. 2-4, fig. one.

2. RF patent № 2169244, Cl. E 04C 3/36, BI No. 17, 06/20/01.

3. RF patent number 2121045, Cl. E 04C 3/32, BI No. 30, 10/27/98.

4. Fonov V.M., Makaricheva N.V. Investigation of mates of reinforced concrete elements. Concrete and reinforced concrete, 1984, No. 7, p. 22-24, Fig. one.

Claims (4)

CLAIM 1. A steel concrete column, comprising a metal pipe filled with concrete, which forms a reinforced concrete core in the pipe cavity, containing longitudinal rod reinforcement, characterized by the height of the column in mutually perpendicular directions along the main axes of the cross section of the concrete core, along its entire width transverse rods with the formation in each plane of the cross-section of the lattice column and fixing them at the ends in the steel wall of the pipe; the rods of the longitudinal reinforcement of the reinforced concrete core are about unified into packets as a group of closely spaced rods and each packet on its perimeter covered by clamps or wound reinforcement wire, and the package longitudinal reinforcement rods placed in the cells grids formed by transverse rods. 2. Staletrubeton column according to claim 1, characterized in that it is made of a cylindrical shape and contains discrete steel strip lining in the places of fixing the transverse rods. - 3 010211 3. Staletrubeton column according to claim 1, characterized in that it is made in the form of a prism of rectangular cross-section and contains on the side faces in the form of bandages steel strip lining, in which the ends are fixed transverse rods. 4. Staletrubeton column according to claims 1 to 3, characterized in that the grids formed by transverse rods are placed in the cross-sections of the column with a step along its height of not more than 0.56, where 6 is the cross-sectional size of the column along its smallest side.