RU2473750C1 - Joint of composite tube confined concrete rods - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: joint of composite tube confined concrete rods is formed by tubes, which are filled by concrete. Concrete is laid into a tube under a force higher than operational load. Concrete is limited at one end of the tube moving under action of the force with a plug with a stop. At the other end of the tube the concrete volume is fixed with the plug, some of which is placed in the pipe end. The external part of the plug is placed into the open end of the tube confined concrete rod, to which the structure is joined. With a certain volume of concrete, a guaranteed gap is provided between ends of joined tubes. The joint is covered with a coupling, the position of which is fixed with a support ring.

EFFECT: elimination of welded joints making during assembly, reduced effect of subsidence phenomena in concrete at structure operation and elimination of longitudinal shift of concrete under load.

1 dwg

Description

The invention relates to the field of construction, and more specifically to concrete structures. Over the past decades, pipe-concrete structures have become widespread in bridge construction, in the construction of high-rise buildings, as well as in foundation engineering.

At the same time, the construction of connecting composite tubular rods to date have not had a satisfactory solution.

The known design of the interface of the core section of the concrete rods at the joints (A.I. Kikin, R.S. Sanzharovsky, V.A. Trull. Structures of steel pipes filled with concrete. M., Stroyizdat, 1974, p. 18, Fig. 11 ), despite the relatively simple structural solution of the joint, the problems of the influence of non-linear deformations of concrete and the elastic deformation of the steel shell are not resolved in the presented connection of concrete pipes, as a result of which the joint work of concrete and steel is not possible to ensure, which can lead to loss of stability composite rod in compression and in particular this may occur when loaded eccentrically-compressed composite rods.

The flange joint of the concrete rod has the same disadvantages (A.I. Kikin, R.S. Sanzhirovsky, V.A. Trull. Structures of steel pipes filled with concrete. M., Stroyizdat, 1974, p. 18, Fig. 12) .

The closest in technical essence are the constructive solutions of telescopic pipe joints (A.I. Kikin, R.S. Sanzhirovsky, V.A. Trull. Structures of steel pipes filled with concrete. M., Stroyizdat, 1974, p. 19, fig. .fourteen).

However, the design of telescopic pipe joints is effective only for pipes not filled with concrete. High-quality concrete filling of composite rods formed from pipes with telescopic joints does not have a technological solution, and when the concrete core is loaded, not only plastic deformation is possible, but also a longitudinal shear of concrete along the inner surface of the pipe due to the relatively insufficient adhesion of concrete to the metal surface. In addition, a large number of welds causes local heating of the concrete core, followed by dehydration and destruction of the concrete core.

Thus, when developing a new joint design, it is necessary to solve the following problems:

- to exclude the performance of any welded joints during the installation of composite pipe-concrete structures;

- reduce the effect of shrinkage phenomena in concrete on the operation of the structure;

- eliminate longitudinal shear of concrete under load.

These tasks are solved when developing a new joint design for composite pipe-concrete rods.

Firstly, in order to exclude any movement of concrete along the inner surface of the pipe (longitudinal shear) under load, the pipe is open only from one end; and the other end closes securely. Thus, when filling the pipe, concrete can be considered as a pseudo-fluid placed in a certain volume, while concrete when filling the pipe under pressure and vibration can be obtained with improved physical and mechanical properties, and concrete hardening in a closed volume at a pressure equal to the period of operation of the structure, shrinkage and creep of concrete will be minimized.

In order to prevent reverse creep in concrete after removing technological loads during the manufacture of the structure, a plug is provided; the position during molding of concrete is fixed with special stoppers. At the same time, during operation of the structure, the plug can move, transferring the load to the concrete core.

The closed end of the pipe is made in a relatively small area with a diameter equal to the inner diameter of the pipe to which the pipe is attached.

A certain gap is left between the ends of the pipes to be joined so that the operational load is transmitted only to the concrete core, and only tensile stresses from the pressure of the concrete are perceived by the pipe walls.

The joint of the concrete pipe rod is closed by a coupling, which during installation is pushed from the side of the rod to be attached. In the design position, the coupling is installed and fixed by moving to the support ring. In this case, the outer diameters of the pipes to be connected and the inner diameter of the coupling must be prepared with the appropriate tolerances and the cleanliness of the processing of the mating surfaces.

It should be noted that the coupling is also designed to connect any supporting structures to the concrete pipe stand (beams, floor slabs, communications, etc.).

In this case, fastening of structures can be carried out not only on bolts, but also on welded joints, since the effect of temperature on concrete will be excluded.

In addition, in the event of nonlinear deformation in the concrete core, it is possible to compensate for the movement of the structure due to the movement of the coupling.

The invention is illustrated in the drawing, where figure 1 shows a schematic diagram of the proposed design.

The metal pipe 1 is filled with concrete 2, one end of the pipe is open and closed by a plug 3 moving under an external force, the position of which is fixed by a stopper 4, a plug 5 is installed from the other end of the pipe, part of which is fixed in the pipe 1, and the outer part of the plug 5 is placed in the open end a concrete pipe to which the structure is docked, while a certain volume of concrete 2 provides a guaranteed gap between the ends of the metal pipes 1, and the joint is closed by a sleeve 6, the position of which is fixed Xia support ring 7.

Given all of the above, it should be noted that the tasks set during the development of a new design of the joint of concrete pipes, basically performed:

- the connection of the rods can be made without welding, which will guarantee the high physical and mechanical properties of the concrete core directly in the joint, moreover, the presence of a sleeve that closes the joint will allow local strengthening of metal pipes;

- due to the fact that the hardening of the concrete laid in the pipe is carried out in a closed volume under a load equal to the operational load, the strength of concrete will be increased, and non-linear deformations will be minimized;

- the new design of the developed joint of the finished pipe-concrete structures eliminates the longitudinal shift of the concrete core relative to the surface of the pipe, since during concreting it is possible to compress the concrete core and pre-stretch the metal pipe, which will provide sufficiently high adhesion of concrete to the metal surface.

Claims (1)

The joint of composite pipe-concrete rods formed by pipes that are filled with concrete, characterized in that the concrete is laid in the pipe under a force slightly higher than the operational load, and is limited from one end of the pipe by a plug with a stopper moving under the influence of force, and the volume of concrete is fixed from the other end of the pipe a plug, a part of which is placed at the end of the pipe, and the outer part of the plug is placed in the open end of the concrete pipe to which the structure is docked, with a certain volume of concrete a guaranteed clearance provided between the ends of the pipe and joint sleeve is closed, the position of which is fixed the support ring.

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