CN101457548A - Node for connecting round steel tube concrete column with reinforced concrete floor and method for making same - Google Patents

Abstract

The invention discloses a joint for connecting a round steel pipe concrete column and a slab floor and a manufacturing method thereof. A round steel pipe is internally built with concrete, at least one shearing resistant ring rib clings to and is welded at the outer side of the steel pipe along the circumference of the steel pipe; a ring beam is positioned at the outer side of the round steel pipe, and reinforcing steel bars arranged along the ring direction and hoop reinforcements distributed along the radial direction in a radial shape form a reinforcing cage; a whole slab floor is formed by concrete placement. When in preparation, the prefabricated ring beam reinforcing cage is processed in the fabricating yard or the factory. After the reinforcing cage is lifted, a slab floor framework beam is bound, and then the concrete of the ring beam and the slab floor are built at the same time, so that the whole slab floor is formed. The joint steel pipe is not provided with a punching component and a stiffening ring plate, and the section of the steel pipe is not cut, so that the concrete placement in the pipe is not affected. The joint has reasonable transmission force, definite stress, simple form, high bearing capacity, good shock resistant performance and convenient construction, can comparatively save materials, and has great significance in further popularizing the application of encased structures in the projects as well as good engineering application prospect.

Description

Joints and manufacturing methods for connecting circular steel pipe concrete columns and reinforced concrete floors

technical field

The invention relates to a connection node between a concrete column and a concrete beam in structural engineering in civil engineering, in particular to a novel node for connecting a circular steel pipe concrete column and a reinforced concrete floor and a manufacturing method thereof.

Background technique

In the mid-1960s, especially after the 1990s, CFST has been widely used in high-rise and super high-rise buildings, long-span bridges and other projects in my country due to its excellent mechanical properties and cost performance. On the one hand, due to the restraining effect of the steel pipe on the filled concrete, the concrete is in a stress state of three-dimensional compression, so that its compressive strength can be fully exerted; on the other hand, due to the filling effect of the concrete, the buckling resistance of the steel pipe under the action of axial force is improved. ability. With its very reasonable combination of materials, the steel tube concrete structure can give full play to and utilize the respective characteristics of steel and concrete materials, achieve complementary advantages in performance, improve the bearing capacity of components, and have good plasticity and toughness at the same time. The application of high-strength steel provides a new way. The use of concrete-filled steel tube structures (especially circular concrete-filled steel tube columns) can save a lot of building materials and facilitate construction, and the economic benefits are also obvious.

At the same time, due to the current national conditions of our country, high-rise buildings will mainly adopt cast-in-place reinforced concrete beam-slab floors now and for a long time in the future. How to solve the connection between the steel pipe concrete column and the reinforced concrete beam-slab floor has been perplexing the engineering field. As a concrete-filled steel tube beam-column joint, it must be able to reliably transmit the shear force and bending moment from the beam-slab, and the force transmission path must be direct and clear, with sufficient ductility to meet the requirements of "strong columns and weak beams, strong nodes, and weak members." "Seismic Design Principles. Therefore, the connection between the steel tube concrete column and the reinforced concrete floor is one of the key technologies that must be solved.

At present, the concrete-filled steel pipe columns and other connection nodes of reinforced concrete floors used in engineering have complex structures to varying degrees, heavy welding workload, complicated installation, hindering the pouring of concrete in the pipes, and opening holes in the steel pipe wall affect the bearing capacity of the concrete-filled steel pipe columns. Strength and other shortcomings. Proposing a new connection node between concrete-filled steel tube columns and reinforced concrete beam-slab floors with reasonable force transmission, safety and economy, and convenient construction has become the key to give full play to the advantages of concrete-filled steel tube structures and popularize concrete-filled steel tube structures, and it is an urgent problem to be solved in the engineering field .

Contents of the invention

The object of the present invention is to provide a joint between a circular steel tube concrete column and a reinforced concrete floor with clear force transmission, which can fully ensure the safety and reliability of the joint, is convenient for construction, saves materials and is economical, and a manufacturing method thereof.

The object of the present invention is achieved through the following technical solutions:

The joint between the circular steel pipe concrete column and the reinforced concrete floor includes a circular steel pipe, a floor frame beam or a beamless floor slab, a ring beam, and a shear ring welded to the outside of the circular steel pipe; A shearing ring bar is pasted and welded on the outside of the steel pipe along the circumference of the steel pipe; the ring beam is located outside the round steel pipe, and a reinforcement cage is formed by steel bars arranged in the circumferential direction and stirrups arranged radially in the radial direction; the cross-sectional height of the ring beam is greater than the section height of the frame beam of the floor or the thickness of the slab without beam, the section width of the ring beam is not less than the section width of the frame beam or the thickness of the slab without beam, the reinforcement of the frame beam of the floor or the reinforcement of the slab of the slab without beam The beams are anchored and poured with concrete to form an integral concrete floor.

To further achieve the purpose of the present invention, the ring beam stirrups are radially arranged.

When the height of the ring beam is greater than or equal to 450mm, ring ribs are arranged along the height direction on both sides of the ring beam, the diameter of the ribs is not less than 12mm, and the distance between them is not greater than 200mm.

The length of anchoring of the steel bar of the floor beam slab into the ring beam is greater than or equal to the corresponding anchoring length Lae.

The shear ring is a round or square steel bar.

The section height of the ring beam is 50mm greater than the section height of the floor frame beam or the thickness of the beamless floor slab.

A method for making a joint between a circular steel pipe concrete column and a reinforced concrete floor includes the following steps and process conditions:

(1) Weld at least one shear girth to the outside of the steel tube wall of the circular steel tube concrete column in advance;

(2) The height of the beam section of the formwork of the ring beam is made larger than that of the frame beam or the beamless floor slab, and the section width of the ring beam is not less than the section width of the frame beam or the thickness of the beamless floor slab. Board completed at the same time;

(3) The inner ring reinforcement of the ring beam and the outer ring reinforcement of the ring beam are uniformly arranged on the upper and lower parts of the ring beam along the ring direction of the ring beam according to the calculated amount of reinforcement, and the ring beam stirrups are radially arranged along the radial direction;

(4) The joints of the ring beam inner ring steel bar and ring beam outer ring steel bar are welded or mechanically connected, and the tensile strength of the joint is not less than the ring bar;

(5) Ring beam inner ring reinforcement, ring beam outer ring reinforcement and ring beam hoops are bound to form ring beam reinforcement cage;

(6) The reinforcement cage is hoisted into the formwork of the ring beam, and the frame beam and floor reinforcement are extended into the ring beam reinforcement cage for anchoring;

(7) The concrete of the ring beam is poured together with the floor beam slab, and its concrete strength grade is not less than that of the connected beam slab.

When the height of the ring beam is greater than or equal to 450 mm, the step (4) further includes disposing ring ribs along the height direction on both sides of the ring beam, the diameter of the ribs is not less than 12 mm, and the distance between them is not greater than 200 mm.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

(1) The present invention proposes a new type of joint between a circular steel tube concrete column and a reinforced concrete floor. A reinforced concrete ring beam is arranged around the circular steel tube concrete column to transmit the bending moment at the end of the frame beam. The outer surface is pasted and welded with circular (or square) steel bars, called shear rings, which are used to transmit shear force. The production process is simple, the force is reliable and reasonable, the steel consumption is small, and the cost is low.

(2) The joint bearing capacity is high, and the seismic performance is good. The bearing capacity of the node is higher than the bearing capacity of the floor frame beam connected to it; the application of the shear ring has a high safety reserve; Weak beam" seismic structural requirements.

(3) The node ring beam has no directionality, is easy to install, and is convenient to connect with frame beams in any direction.

(4) The construction is convenient. The binding requirements of reinforced concrete ring girder steel cage are the same as those of ordinary concrete beams; the shear ring is only connected to the steel pipe wall through fillet welds, and the welding workload is small, and it can be completed in the factory; except for the extension of the steel pipe In addition, there is no welding workload on site, and the construction is convenient.

(5) There are no core-piercing members and stiffening ring plates inside the steel pipe, no holes need to be opened in the steel pipe wall, and the cross section of the steel pipe is not weakened, which can ensure the cross-sectional bearing capacity of the steel pipe concrete column and facilitate the pouring of concrete inside the pipe.

Description of drawings

Figure 1 is a top view of the joint between the circular steel pipe concrete column and the reinforced concrete floor.

Fig. 2 is a front view of the connection node between the circular steel pipe concrete column and the reinforced concrete floor.

Fig. 3 is a sectional view taken along line A-A of Fig. 2 .

Fig. 4 is a sectional view taken along line B-B of Fig. 1 .

Detailed ways

The present invention will be described in further detail below with reference to the accompanying drawings and examples, but the embodiments of the present invention are not limited thereto.

As shown in Figures 1, 2, 3, and 4, the connection nodes between the circular steel pipe concrete column and the reinforced concrete floor include: circular steel pipe 1, floor frame beam 2, ring beam 3, ring beam inner ring reinforcement 4, ring beam outer ring reinforcement 5 , Ring beam stirrup 6, shear ring 7. The ring beam 3 is located on the outer side of the round steel pipe 1, and the ring beam 3 is formed into a ring structure by concrete pouring of the upper and lower ring beam inner ring steel bars 4, ring beam outer ring steel bars 5 and ring beam stirrup bars 6, wherein the ring beam inner ring steel bars 4, ring beam The beam outer ring reinforcement 5 and the ring beam stirrup 6 are bound to form a reinforcement cage, the ring beam inner ring reinforcement 4 and the ring beam outer ring reinforcement 5 are arranged on the upper and lower parts of the ring beam, and the ring beam stirrup 6 is bound to the ring beam inner ring reinforcement 4 and the ring beam. On the outer ring steel bar 5 of the beam, the distance between the ring beam stirrups 6 is determined by force calculation, and the ring beam stirrups 6 are radially arranged; when the beam height is ≥ 450 mm, they are arranged along the height direction on both sides of the ring beam Circumferential waist reinforcement, the diameter of the waist reinforcement is not less than 12mm, and the distance between them is not greater than 200mm; the section height of the ring beam 3 is greater than the height of the floor frame beam section 2 or the thickness of the beamless floor slab, preferably greater than 50mm; the section width of the ring beam 3 Not less than the width of the frame beam section or the thickness of the beamless floor, the steel bars of the floor frame beam 2 or the steel bars of the beamless floor slab are anchored in the ring beam 3, and the integral concrete floor is formed by pouring concrete; For concrete, the shear ring on the outside of the pipe wall is welded horizontally against the shear ring. The shear ring 7 is a round or square steel bar, and the welding between the shear ring 7 and the outer wall of the steel pipe column 1 adopts a fillet weld.

The floor frame beam 2 is a reinforced concrete beam, and the upper longitudinal bars 8 of the frame beam, the lower longitudinal bars 9 of the frame beam and the stirrups 10 of the frame beam constitute the steel bar structure of the floor frame beam 2 . The anchoring of the steel bars of the floor frame beam 2 in the ring beam 3 means that the upper longitudinal bars 8 of the frame beam and the lower longitudinal bars 9 of the frame beam extend into the ring beam 3 and meet the requirements of the seismic anchorage length Lae. The steel bars of the beamless floor slab are anchored in the ring beam 3 and the manufacturing method is the same as that of the floor frame beam 2.

The preparation process of the joint between the circular steel pipe concrete column and the reinforced concrete floor is as follows:

The first step is to determine the cross-sectional size of the reinforced concrete ring beam 3. The cross-sectional height of the ring beam 3 is 50 mm larger than the intersecting floor frame beam 2, and the floor frame beam 2 with the largest cross-sectional height is used for comparison; the cross-sectional width of the ring beam 3 is different. It is smaller than the section width of the frame beam 2 with the largest section width intersecting with it, and meets the length of the anchoring horizontal section of the longitudinal reinforcement 8 of the frame beam. Node formwork is completed at the same time as the floor.

The second step is to paste and weld the shear ring 7 on the outer side of the steel pipe wall of the circular steel pipe concrete column. There are two shear rings, one in the middle of the ring beam and the other in the lower part.

The third step is to make a reinforcement cage around the reinforced concrete ring beam 3 of the circular steel pipe concrete column 1 . The number of ring bars and stirrups of the reinforcement cage is determined by calculation and construction.

The fourth step is to make a reinforcement cage on the ground or other working surfaces according to the determined amount and geometric dimensions of the ring reinforcement and stirrup reinforcement.

Step 5 After the hoisting of the steel cage is completed, the frame beam and floor steel bars are extended into the ring beam for anchoring. After the side formwork of the ring beam is sealed, concrete can be poured to form an integral concrete floor (concrete pouring in the steel tube concrete should be poured before the floor pouring, otherwise the support should be kept to avoid stress on the empty steel pipe).

In the joint between the circular steel pipe concrete column and the reinforced concrete floor, the steel pipe adopts Q345B, the strength of the concrete is the same as that of the floor concrete, the strength of the ring beam steel bar is the same as that of the floor frame beam, both are grade III steel, the welding rod adopts E50 type, and the welding flux 5014, the fillet weld between the shear ring and the steel pipe wall meets the quality requirements of the third-grade weld.

As described above, the present invention can be preferably realized.

Claims (8)

1, the node that is connected with reinforced concrete floor of concrete-filled circular steel tube column is characterized in that: comprise round steel pipe, flooring Vierendeel girder or arch without beam plate, ring beam and be welded in the anti-shear ring in the round steel pipe outside; Concreting in the described round steel pipe, at least one anti-shear ring muscle paste along the steel pipe circumference and are welded in the steel pipe outside; Described ring beam is positioned at the round steel pipe outside, constitutes reinforcing cage by the reinforcing bar of arranging along hoop with the stirrup that radially becomes radial arrangement; Described ring beam depth of section is greater than the thickness of flooring Vierendeel girder depth of section or arch without beam plate, the ring beam breadth of section is not less than the thickness of the wide or arch without beam in Vierendeel girder cross section, the anchoring in ring beam of the reinforcing bar of the reinforcing bar of flooring Vierendeel girder or arch without beam plate forms the monolithic concrete superstructure with concreting.

2, the node that is connected with reinforced concrete floor of concrete-filled circular steel tube column according to claim 1, it is characterized in that: described ring beam stirrup radially becomes radial arrangement.

3, the node that is connected with reinforced concrete floor of concrete-filled circular steel tube column according to claim 1, it is characterized in that: when the height of ring beam 〉=450mm, two sides at ring beam dispose hoop waist muscle along short transverse, and waist muscle diameter is not less than 12mm, and its spacing is not more than 200mm.

4, the node that is connected with reinforced concrete floor of concrete-filled circular steel tube column according to claim 1 is characterized in that: described superstructure beam reinforced steel bar anchors into the length of ring beam more than or equal to corresponding anchorage length Lae.

5, the node that is connected with reinforced concrete floor of concrete-filled circular steel tube column according to claim 1 is characterized in that: described anti-shear ring is circular or square reinforcing bar.

6, the node that is connected with reinforced concrete floor of concrete-filled circular steel tube column according to claim 1, it is characterized in that: described ring beam depth of section is greater than the thickness 50mm of flooring Vierendeel girder depth of section or arch without beam plate.

7, the preparation method of the node that is connected with reinforced concrete floor of the described concrete-filled circular steel tube column of claim 1, its feature comprises the steps and process conditions:

(1) in advance at least one anti-shear ring is welded in the concrete-filled circular steel tube column steel pipe walls outside;

(2) the beam section height of the template of ring beam is made bigger than Vierendeel girder or arch without beam plate, the ring beam breadth of section is not less than the thickness of slab of the wide or arch without beam plate in Vierendeel girder cross section, and template construct and superstructure beam slab are finished the same period;

(3) ring reinforcing bar and ring beam outer shroud reinforcing bar are arranged in the ring beam top and the bottom according to the reinforcing bar amount of calculating along the ring beam hoop is even respectively in the ring beam, and the ring beam stirrup radially becomes radial arrangement;

(4) ring reinforcing bar and the bar splice of ring beam outer shroud are welded to connect or mechanical connection in the ring beam, and the tensile strength of junction is not less than the ring muscle;

(5) ring reinforcing bar, ring beam outer shroud reinforcing bar and the colligation of ring beam stirrup form the ring beam reinforcing cage in the ring beam;

(6) lifting of reinforcing cage is in the template of ring beam, and Vierendeel girder and floor bar stretch into the anchoring of ring beam reinforcing cage;

(7) concrete of ring beam and superstructure beam slab are together built, and its strength grade of concrete is not less than the strength grade of concrete that is attached thereto beam slab.

8, the preparation method of the node that is connected with reinforced concrete floor of concrete-filled circular steel tube column according to claim 7, it is characterized in that when ring beam height 〉=450mm, described step (4) also is included in two sides of ring beam along short transverse configuration hoop waist muscle, waist muscle diameter is not less than 12mm, and its spacing is not more than 200mm.

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