TWI769969B - Joint structure of concrete encased steel composite beams - Google Patents

Abstract

A joint structure of concrete encased steel composite beams is provided, wherein the joint structure of concrete encased steel composite beams comprises a main column; a steel beam having a web plate, at least one wing plate, at least one surrounding space, and a connecting terminal, the connecting terminal is connected to the main column, the web plate and the at least one wing plate surround and define the surrounding space; at least one first isolated area located in the surrounding space and close to the connecting terminal; and a concrete body covering the main column and at least a portion of the steel beam. The concrete body is not filled in the first isolated area.

Description

Steel beam joint structure of steel frame cladding concrete beam members

The present invention relates to a steel beam joint structure of a steel frame cladding a concrete-shaped beam member, in particular to a steel beam joint structure of a steel frame cladding a concrete-shaped beam member of a building structure.

At present, the number of buildings using steel-reinforced concrete structures is gradually increasing. In the past earthquake damage, it is often found that the joint between beams and columns has the highest probability of damage, and the damage at the joints of beams and columns can easily lead to the collapse of the building structure. threat to life. Therefore, in order to increase the toughness of the beam-column junction in the building structure, the steel beam structure is usually reinforced or processed, and the plastic deformation development area is removed from the beam-column junction. The seismic method is to reduce the width of the wing plate of the steel beam to reduce the bending moment strength in this area, so that this area can be subdued first, and plastic deformation is generated to dissipate the seismic energy, thereby achieving excellent seismic behavior.

In addition, the traditional steel beam structure in the building structure usually needs to be treated with fireproof coating such as sandblasting during the fireproof treatment. Such fireproof treatment methods are often expensive and harmful to the health of the constructors. Therefore, in recent years Come, the industry has developed a use Concrete is used as a fire-resistant coating material for steel beam structures. This method uses concrete to coat steel beam structures, which can reduce the cost of fire-resistant material coating. It is environmentally friendly and fast in construction. The coated steel beam structure is suitable for various types of exterior walls. The connection is beneficial to the subsequent construction operations, so the construction method is widely used.

However, in the steel beam structure constructed according to this method, the plastic deformation zone formed by cutting the wing plate originally used as the energy dissipation beam is also covered with concrete. Therefore, the ductility capacity of the plastic deformation zone may be insufficient or easily generated. Poor damage mechanism, which in turn affects the ability to dissipate energy when an earthquake occurs.

Therefore, there is an urgent need for a novel steel-beam joint structure of steel-reinforced concrete-shaped beam members. By isolating the steel beam and the concrete, it can reduce the restraint of the concrete on the steel beam, improve its deformation development ability, and avoid unexpected occurrences. the failure mode to ensure the seismic characteristics of the building structure.

A main purpose of the present invention is to provide a steel beam joint structure with a steel frame cladding a concrete beam member, including: a main column body; a steel beam having a web, at least one wing plate, at least one surrounding space, and a a connecting end, the connecting end is connected with the main cylinder, the web and the wing plate define the surrounding space; at least one first isolation area is located in the surrounding space and close to the connecting end; and a concrete pouring The body wraps the main column body and at least part of the steel beam; wherein, the poured concrete body does not fill the first isolation area.

In one embodiment, the first isolation area is hollow and not covered by the poured concrete body.

In one embodiment, the steel-beam joint structure of the steel-frame-clad concrete-shaped beam member further includes a first filling material disposed in the first isolation area, and the concrete pouring body covers the first filling material.

In an embodiment, the steel beam joint structure of the steel frame cladding the concrete beam member further includes a second isolation area, located on the outer surface of the wing plate, and corresponding to the first isolation area, the second isolation area. The isolated area is hollow and not covered by the poured concrete body.

In an embodiment, the steel-beam joint structure of the steel-reinforced concrete-shaped beam member further includes a second filling material disposed in the second isolation area, and the concrete pouring body covers the second filling material.

In one embodiment, the first filling material and the second filling material are each composed of a porous material or an elastic material.

In one embodiment, the porous material is at least one selected from the group consisting of foam, foam, and styrofoam, and the elastic material is at least one selected from the group consisting of rubber and plastic .

In one embodiment, the steel beam is an H-shaped steel beam, an L-shaped steel beam, a U-shaped steel beam, or a rectangular steel beam.

In one embodiment, the steel beam is the H-shaped steel beam.

In one embodiment, the steel beam joint structure of the steel frame cladding the concrete beam member further includes a plurality of reinforcing bars, the reinforcing bars surround the steel beam and the main column body, and are embedded in the concrete cladding body .

In one embodiment, the web or the wing plate of the steel beam near the connecting end has an energy dissipation structure.

In one embodiment, the energy dissipation structure means that at least one of the web or the wing is cut with a cutting portion by a cutting method.

The steel beam joint structure of the steel frame cladding concrete beam member provided by the present invention mainly proposes to set a first isolation area and a second isolation area at the position adjacent to the junction between the steel beam and the column without pouring concrete, or to use The filling material is filled to isolate the coated concrete, thereby reducing the binding of the concrete to the steel frame, so as to improve the deformation capacity of the steel frame, ensure its energy dissipation effect, and avoid unexpected failure modes when an earthquake occurs.

100,200: Steel beam joint structure

1: main cylinder

2: Steel beam

21: Web

22: Wings

23: Surrounding Space

24: Connection end

25: Energy dissipation structure

251: Cutting part

3: The first isolation area

4: Second isolation area

5: Rebar

6: Concrete pouring body

7: The first filling material

8: Second filling material

1A is a partial perspective view of the steel beam joint structure of the steel frame cladding concrete beam member according to the first embodiment of the present invention; FIG. 1B is the steel frame cladding concrete beam member according to the first embodiment of the present invention. A partial perspective view of a steel-beam joint structure of a beam member; FIG. 2A is a perspective view of a steel-beam joint structure of a steel-reinforced concrete-clad beam member according to a second embodiment of the present invention; FIG. 2B is a second embodiment of the present invention. Partial perspective view of the steel beam joint structure of the steel frame cladding concrete beam member of the embodiment; FIG. 2C is a partial three-dimensional view of the steel frame cladding concrete beam member according to the second embodiment of the present invention. Schematic diagram; Fig. 3 is the cross-sectional schematic diagram of the steel beam joint structure of the steel frame cladding concrete beam member of the second embodiment of the present invention; Fig. 4 is a schematic diagram of the shape of the cutting part of the wing plate of Example 1 and Comparative Example 1 of the present invention; Fig. 5 is a schematic cross-sectional view of the steel beam joint structure of Comparative Example 1 of the present invention; Fig. 6 is the displacement in a test example of the present invention Figure 7 is a schematic diagram of the failure mode of Example 1 of the present invention; and Figure 8 is a schematic diagram of the failure mode of Comparative Example 1 of the present invention.

Please refer to FIG. 1A and FIG. 1B at the same time, which are schematic diagrams of a steel beam joint structure 100 in which a steel frame is covered with a concrete beam member according to a first embodiment of the present invention, and FIG. 1A shows the A partial three-dimensional schematic diagram of the steel beam joint structure 100 of the steel frame cladding concrete beam member before concrete is not yet clad, including a main column 1, a steel beam 2, two first isolation areas 3, and two second isolation areas. Area 4, and a plurality of reinforcing bars 5, and FIG. 1B shows the steel beam joint structure 100 of the concrete beam member cladding the steel frame when a concrete casting body 6 wraps the structure shown in FIG. 1A. Stereoscopic diagram.

In this embodiment, the main column body 1 is an H-shaped steel. However, in other embodiments, other steel materials in the art that can be used as the main column can be used according to design, for example, a square-shaped steel pipe.

In this embodiment, the steel beam 2 is an H-shaped steel having a web 21 , two wing plates 22 , two surrounding spaces 23 , a connecting end 24 , and an energy dissipation structure 25 . It is connected with the main column body 1 through the connection end 24, and the connection method of the steel beam 2 and the main column body 1 can be any connection method known in the art, which can be selected according to the design. The surrounding space 23 is defined by the web 21 and the wings 22 surrounded by the The steel beam 2 is H-shaped steel, so the number of the surrounding spaces 23 is 2. In other embodiments, for example, if the steel beam used is L-shaped steel, the web 21 and the wing plate 22 are surrounded by The defined number of surrounding spaces is 1. However, in other embodiments, the steel beam 2 can be selected from L-shaped steel beams, U-shaped steel beams, or rectangular steel beams according to requirements and designs, without particular limitations. The energy dissipation structure 25 is disposed on the web 21 or the wing plate 22 near the connecting end 24 . In this embodiment, the energy dissipation structure 25 refers to the cutting method of each of the wings 22 There are two symmetrical cutting portions 251 for cutting. The cutting shape and width of the cutting portions 251 can be designed according to the required plastic deformation ability and strength, and there is no particular limitation. In other embodiments, the energy dissipation structure 25 may be other energy dissipation structures provided on steel beams known in the art.

The first isolation areas 3 are located on the surrounding spaces 23 on both sides of the web 21, and are close to the connecting end 24, while the second isolation areas 4 are located on the outer surface of the wing plate 22, corresponding to the The first isolation area 3 is also close to the connection end 24 .

The steel bar 5 surrounds the steel beam 2 and the main column 1 to serve as the skeleton of the concrete pouring body 6. The surrounding method of the steel bar 5 can be in accordance with a common method in the art, and the number and surrounding method are not particularly limit.

The concrete pouring body 6 uses the steel bar 5 as a skeleton, and then covers the main column 1 and part of the steel beam 2. The first isolation area 3 and the second isolation area 4 are hollowed out and not covered by The poured concrete body 6 is covered.

In the steel beam joint structure of the above embodiment, since neither the first isolation area 3 nor the second isolation area 4 is covered by the concrete pouring body 6, the energy dissipation on the steel beam 2 The energy dissipation capacity of the structure 25 is not limited by the poured concrete body 6 .

The second embodiment of the present invention is shown in FIG. 2A to FIG. 2C . The steel beam joint structure 200 of the steel frame cladding the concrete beam member also includes a main column 1 , a steel beam 2 , and two second beams. An isolation area 3, two second isolation areas 4, a plurality of reinforcing bars 5, and a concrete pouring body 6, wherein the main column 1, the steel beam 2, the first isolation area 3, the second isolation area The isolation regions 4 are the same as those in the above-mentioned embodiment, so they will not be repeated here. The present embodiment further includes two first filling materials 7 and two second filling materials 8 . Wherein, FIG. 2A shows a steel beam joint structure 200 in which the steel reinforcement 5 has not yet been tied and the concrete cast body 6 has not yet been set with a steel frame clad with a concrete beam member. The first filling materials 7 are respectively arranged in The first isolation area 3 and the second filling material 8 are respectively disposed in the second isolation area 4 ; FIG. 2B shows the state of surrounding the steel beam 2 and the main column 1 with the steel bar 5 . In this way, different from the first embodiment, the steel bar 5 of this embodiment surrounds the whole of the steel beam 2, including the first isolation area 3 and the second isolation area 4, that is, around the first filling material 7 and the outside of the second filling material 8; and FIG. 2C shows that in this embodiment, the concrete pouring body 6 covers the main column 1, the steel beam 2, and the first filling material 7 and the second filling material 8 , so that the appearance of the steel beam joint structure 200 in which the steel frame is clad with the concrete-shaped beam member is entirely covered by the concrete pouring body 6 . The first filling material 7 and the second filling material 8 are composed of styrofoam, and in other embodiments, common porous materials or elastic materials can be selected, such as foam materials, foam materials, etc. Materials such as cotton, styrofoam, rubber, or plastic can be used as long as their strength does not cause a restraining effect on the steel beam, and at the same time exerts an insulating effect so that the clad concrete pouring body 6 does not contact the energy dissipation structure 25 .

Furthermore, since the first filling material 7 and the second filling material 8 are respectively disposed in the first isolation area 3 and the second isolation area 4, the concrete pouring body 6 does not contact the steel. The energy dissipation structure 25 on the beam 2 .

However, in other embodiments, the second insulating area 4 may not be provided with the second filling material 8 . Therefore, in this embodiment, the poured concrete 6 may be filled into the second insulating area 4 and contact with the second insulating area 4 . The outer surface of the wing plate 22 of the steel beam 2 .

[Specimen design and strength test]

This implementation provides a series of T-shaped beam-column joint structural specimens, and the beam-column joint bending behavior is observed by simulating the cyclic force characteristics of the actual building structure caused by an earthquake under a repeated load. First, the configuration of the specimens of Example 1 and Comparative Example 1 is as follows. The steel of the two groups of specimens is SN490B, the size of the steel beam is BH 750x400x12x32mm, the size of the coated concrete is 950x600mm, and the steel column part is BOX 700x700x28mm. The dimensions after covering with concrete are 900x900mm. The flanges in the middle and lower parts of the steel beams of each group of specimens are equipped with shear nails with a spacing of 200mm.

In detail, FIG. 4 shows the shape of the blade cutting portion of Example 1, wherein w1 is 36 mm, w2 is 61 mm, w3 is 400 mm, d1 is 375 mm, and d2 is 671 mm, and in Example 1, the first Filling material made of Styrofoam is arranged in an isolated area, and concrete is wrapped around the outside of the filling material.

The shape of the blade cutting portion of Comparative Example 1 is the same as that of Example 1, as shown in FIG. 4 . However, in the specimen of Comparative Example 1, as shown in FIG. 5 , the concrete pouring body 6 is covered with Main column 1 and steel beam 2.

The configuration of this strength test is to set the column upright and place it on the west side, and set up a steel support chair under the column to match the height of the hydraulic jack used for the test. A spacer is added in the middle of the floor and fixed with a pre-force with a screw. In addition, a screw is also used between the upper and lower ends of the column and the reaction wall to apply a pre-force between the electric sheet and the steel support and the test body for fixing. The end part of the steel beam (3350mm from the center of the column) and two hydraulic jacks are fixed with bolts, and a gasket is also added between the hydraulic jack and the strong floor, and the screw is used to apply pre-force to fix it to simulate the beam-column joint bearing repeated Behavior under load.

The load is applied using a displacement-increasing process, in which the drift ratio and cycle are both set according to AISC specifications for beam-column joints subjected to repeated loads, and the drift ratio corresponds to the cycle. For 0.375%, 0.5%, and 0.75%, 6 loops should be applied, and 1.0% should be applied 4 loops. The loading duration is shown in Figure 6.

The results of the above tests are as follows. The failure modes of Example 1 and Comparative Example 1 are shown in Figures 7 and 8, respectively. By comparing Figures 7 and 8, it can be observed that the steel beam in Comparative Example 1 is teared and damaged. be effectively avoided.

From the above tests, it can be known that in Example 1, the first isolation area is filled with filler material to isolate the concrete-clad steel beam joint structure, the cutting part of the steel beam can be weakened again to ensure that the deformation of the cutting part can be better. Effective development, and there is enough space when deformation occurs without being bound by concrete, and the energy dissipation area is also increased by 41%, indicating that not pouring concrete in the first isolated area of the steel beam can increase the toughness of the steel beam joint structure and energy dissipation capacity.

To sum up, the steel beam joint structure of the steel frame cladding concrete beam member of the present invention can be developed more effectively, and the energy dissipation device mainly arranged at the joint between the steel beam and the main column can be developed more effectively, and the energy dissipation device can be ensured effectively. The strength can be definitely weakened, and it is not affected by the filling of the concrete pouring body. Therefore, the energy dissipation device can have enough space to deform when it is deformed, and its toughness and energy dissipation ability can be improved.

The above-mentioned embodiments are only used to illustrate the embodiments of the present invention and to illustrate the technical characteristics of the present invention, and are not used to limit the protection scope of the present invention. Any changes or equivalent arrangements that can be easily accomplished by those skilled in the art fall within the claimed scope of the present invention, and the scope of the right protection of the present invention should be subject to the scope of the patent application.

100: Steel beam joint structure

1: main cylinder

2: Steel beam

21: Web

22: Wings

23: Surrounding Space

24: Connection end

25: Energy dissipation structure

251: Cutting part

3: The first isolation area

4: Second isolation area

5: Rebar

Claims (12)

A steel beam joint structure of a steel frame covered with a concrete beam member, comprising: a main column body; a steel beam having a web plate, at least one wing plate, at least one surrounding space, and a connecting end, the connecting end and The main column is connected, the web and the wing plate define the surrounding space; at least a first isolation area is located in the surrounding space and close to the connection end; and a concrete pouring body covers the main column body, and at least part of the steel beam; wherein the poured concrete body does not fill the first isolated area. The steel-beam joint structure of the steel-reinforced-concrete-beam member covered by the steel frame as claimed in claim 1, wherein the first isolation area is hollow and is not covered by the concrete pouring body. The steel beam joint structure of the steel frame covered with the concrete beam member according to claim 2, further comprising at least one first filling material disposed in the first isolation area, the concrete pouring body covering the first filling material . The steel beam joint structure of the steel frame cladding concrete beam member according to claim 3, further comprising a second isolation area, located on the outer surface of the wing plate, and corresponding to the first isolation area, the second isolation area The isolated area is hollow and not covered by the poured concrete body. The steel beam joint structure of the steel frame covered with the concrete beam member according to claim 4, further comprising at least one second filling material disposed in the second isolation area, the concrete pouring body covering the second filling material . The steel beam joint structure of the steel frame cladding concrete beam member according to claim 3 or claim 5, wherein the first filling material and the second filling material are respectively a porous material or an elastic material constituted. The steel-beam joint structure of the steel-framed-clad concrete-shaped beam member according to claim 6, wherein the porous material is at least one selected from the group consisting of foamed material, foamed cotton, and styrofoam, The elastic material is at least one selected from the group consisting of rubber and plastic. The steel beam joint structure of the steel frame cladding concrete beam member according to claim 1, wherein the steel beam is an H-shaped steel beam, an L-shaped steel beam, a U-shaped steel beam, or a rectangular steel beam. The steel beam joint structure of the steel frame cladding concrete beam member according to claim 2, wherein the steel beam is the H-shaped steel beam. The steel beam joint structure of the steel frame cladding the concrete beam member according to claim 1, further comprising a plurality of reinforcing bars, the reinforcing bars surround the steel beam and the main column, and are embedded in the concrete pouring body. The steel beam joint structure of the steel frame cladding concrete beam member according to claim 1, wherein the web or the wing plate near the connection end in the steel beam has an energy dissipation structure. The steel beam joint structure of a steel frame cladding a concrete beam member as claimed in claim 11, wherein the energy dissipation structure means that at least one of the wings is cut with at least one cutting portion by a cutting method .

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