RU2249657C1 - Connection method for composite structures and units - Google Patents

Abstract

FIELD: building, particularly connections specially adapted for particular building parts or for particular building structures and units.

SUBSTANCE: method involved using embedded members made as metal cylindrical cartridges arranged in concrete body of units to be connected in joint area thereof and metal connection member. Cylindrical cartridge interior is previously filled with adhesive composition. One end of connection member is placed in metal cartridge of the first unit to be joined, another end is inserted in that of the second one. Flange is welded to metal cartridge end. Flange is bored at 40° - 50° for the depth of 0.5 - 0.7 of flange thickness and conical flange bore passes into cylindrical one having dimension corresponding to metal connection diameter, which forms fixing clawing funnel. Ratio between inner cartridge diameter and connection member diameter is equal to d_c,in/d_cm = 1.5 - 2.0, where d_c,in is inner cartridge diameter, d_cm is metal connection diameter. Wherein resting outline is formed in area of metal cartridge abutment to flange. Resting outline has ledge of not less than 5 mm when connection member diameter is 10 - 30 mm, which prevents shear deformation development, increases squeezing degree and blocks metal connection. Cartridge has length L_c = (10-12)·d_cm, which prevents slip of metal connection.

EFFECT: simplified assemblage technology.

2 dwg

Description

The invention relates to the field of construction, and in particular to methods of connecting prefabricated structures and elements.

Known methods for connecting elements of buildings in which the anchor of one connected element are overlapped with the anchor of another connected element [1,2].

The main disadvantages of the known methods is that to ensure the reliability of the joint, the overlap length should be at least 20-30 anchor diameters, depending on the class of the anchor steel when these anchors are placed in the compressed concrete zone, which is a limitation of the scope of the joint and also leads to an increase metal consumption.

Known methods for connecting reinforced concrete structures by means of couplings or bushings [3, 4, 5, 6, 7].

A disadvantage of the known methods is the complexity of installation due to the variety of technological operations and devices used to connect the rods end-to-end.

There is also a method of connecting elements of prefabricated reinforced concrete structures, in which one of the joined elements has a smooth profile reinforcing outlet with a coupling at the end that is screwed onto a threaded reinforcing outlet protruding from the recess of the supporting part of the other joined element [8].

The disadvantage of this method is the large number and complexity of technological operations, consisting in the need to perform threaded connections, screwing couplings with special devices at a construction site.

A prototype of the claimed technical solution is a method for connecting prefabricated reinforced concrete structures and elements, in which embedded parts made in the form of metal plates and connected to a reinforced concrete structure or element by means of an anchor are welded together directly or through a metal plate [9].

The disadvantage of the prototype is the complexity associated with the exact fixation of the connected structures and elements, pre-treatment of the weld points (chamfering), using additional mounting devices, requires a lot of time, energy. The use of welding contradicts the basic requirements for the development of prefabricated construction, laborious, multi-operation.

The objective of the invention is to simplify the installation technology of prefabricated reinforced concrete structures and elements by increasing labor productivity, eliminating energy-intensive welded joints while maintaining high joint strength.

The essence of the invention lies in the fact that to connect prefabricated reinforced concrete structures and elements use embedded parts made in the form of metal clips of cylindrical shape, placed in concrete of joined elements in the area of the butt joint, the internal volume of which is pre-filled with adhesive composition, and a metal bond, one end which lead into the metal holder of one abutting element, and the other into the metal holder of another abutting element, while to the metal holder at the end a flange is welded, bored at an angle of 40-50 ° to a depth of 0.5-0.7 of the thickness of the flange with a transition to a cylindrical hole along the diameter of the metal bond, which forms a locking catch funnel, the ratio of the inner diameter of the cage to the diameter of the bond is assumed to be

where d _{in.ob is the inner} diameter of the cage;

d _{c is the} diameter of the metal bond,

in this case, a stop contour is formed in the area where the metal holder is adjacent to the flange with a step size of not less than 5 mm with a bond diameter of 10-30 mm, which prevents the development of shear deformations, increases compression and wedges

a metal bond, and the length of the cage L _about taken equal to: L _about = (10-12) d _c , excluding slipping communication.

Thus, the joining of joined reinforced concrete structures is carried out not by welding, but by means of adhesive forces of the adhesive composition, the value of which increases many times due to the constraint of the transverse deformations of the adhesive composition in an enclosed space.

Figure 1 shows a diagram of the method of non-welded butt joints, where: a metal sleeve in the form of a cylinder of one abutting element 1, a metal sleeve in the form of a cylinder of another abutting element 2, flanges 3 and 4 of the ferrule 1 and 2 of the abutting elements, fixing capture funnels 5 and 6 metal clips 1 and 2, metal bond 7, adhesive composition 8.

Figure 2 presents graphs of the dependence of the bearing capacity of the joint N made by the proposed method on the relative embedment depth L _{3 of the} pin connection.

The proposed method is as follows. A metal bond 7 is inserted into a metal holder of a cylindrical shape 1, placed in concrete of one abutting element, the internal volume of which is pre-filled with adhesive composition 8. In this case, the cone-shaped capture funnel 5 self-fixes the connection 7 in the metal holder 1. After that, the second end of the connection 7 is brought into the adjacent a metal clip of a cylindrical shape 2, the inner volume of which is pre-filled with adhesive 8. The cone-shaped capture funnel 6 self-fixes the connection 7 in the metal clip 2. Filling the inner The initial space of clips 1 and 2 by adhesive composition 8 is determined by the displacement of excess adhesive composition 8 into the space formed by funnels 5 and 6. Stresses perceived by the joint lead to transverse deformations of adhesive composition 8 placed in a closed clip 1 and 2 volume. In this case, shear deformations are converted into compression deformations and, due to the effect of transverse expansion of the material, bond 7 in metal clips 1 and 2 are jammed.

Mastics are used as the adhesive composition, which have the property of expanding the volume during hardening or the effect of increasing the coefficient of internal deformations as stress increases (for example, cement-sand mortars on non-shrink expanding cement, gypsum binder, etc.).

As evidence of the operation of the butt joint, figure 2 presents graphs of the dependence of the bearing capacity of the joint N made by the proposed method on the relative embedment depth L ₃ . pin connection.

Curve 1 - pin connection made of reinforcement of the periodic profile of class A-III;

Curve 2 - pin connection made of smooth reinforcement class A-I.

Tests have shown that the bearing capacity of a pin connection depends on the depth of the pin and the grade of steel from which it is made. At the same time, the most reliable are the compounds in which the coupling elements were made of reinforcement of the periodic profile of class A-III and higher without pronounced yield points.

Sources of information

1. Gelfand L.I., Vashalomidze T.A. Horizontal joints of earthquake-resistant panel buildings. “Housing construction”, M., 1986, No. 5, p.7.

2. Guidelines for the design of concrete and reinforced concrete structures of heavy concrete (without prestressing), M .: Stroyizdat, 1978, p. 282.

3. Pasternak P.L. and other Reinforced Concrete Structures, Moscow: Gosstroyizdat, 1961, p. 86.

4. Copyright certificate of the USSR No. 838035, cl. E 04 B 1/58.

5. Japanese application No. 57-3786 of 01/20/1977, according to CL. E 04 C 21/12.

6. Application of Germany No. 3008025 from 01.29.1980, according to class E 04 C 5/16.

7. Japanese application No. 56-7016 of 07/30/1974, according to CL. E 04 C 5/18.

8. Japanese application No. 55-40144 of 11/15/1976, according to CL. E 04 B 1/58 // E 04 C 5/18.

9. Guidelines for the design of concrete and reinforced concrete structures made of heavy concrete (without prestressing), M .: Stroyizdat, 1978, p.307-308.

Claims (1)

The method of joining prefabricated structures and elements using embedded parts, characterized in that for connecting prefabricated reinforced concrete structures and elements use embedded parts made in the form of metal clips of cylindrical shape, placed in concrete of joined elements in the area of the butt joint, the internal volume of which is pre-filled with adhesive composition, and a metal bond, one end of which is led into a metal clip of one abutting element, and the other into a metal clip of another of the abutting element, while a flange is welded to the metal holder at the end, bored at an angle of 40-50 ° to a depth of 0.5-0.7 of the thickness of the flange with a transition to a cylindrical hole in the diameter of the metal bond, which forms a locking catch funnel, the ratio of the inner the diameter of the cage to the diameter of the bond is taken equal

where d _century.ob is the inner diameter of the cage; d _c is the diameter of the metal bond, in this case, an abutment contour is formed in the zone of adjacency of the metal cage to the flange with a step size of at least 5 mm with a bond diameter of 10-30 mm, which prevents the development of shear deformations, increases compression and wedges the metal bond, and the cage length L _{about is} taken equal to L _about = (10-12) d _c , excluding slipping communication.

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