CN103924676B - Prestressing force connects beams of concrete concrete-filled circular steel tube column node - Google Patents

Abstract

The invention relates to a prestressed connected concrete beam circular steel pipe concrete column joint, which belongs to the technical field of building structures. Including circular steel pipe concrete columns, reinforced concrete beams, prestressed tendons, ring plates, channel steel. The circular concrete-filled steel pipe column and the reinforced concrete beam are cast-in-place; the circular steel-filled concrete column and the reinforced concrete beam are connected by prestressed tendons; there is a tunnel at the connection between the circular steel-filled concrete column and the reinforced concrete beam, and a metal bellows is pre-embedded in the tunnel; The ring plate is welded at the connection between the circular steel pipe concrete and the beam, and there are corresponding holes on the ring plate; the channel steel is welded on the round steel pipe. The invention has fast construction speed, can effectively increase the shear bearing capacity of nodes, enhance its connection performance, and has broad application prospects.

Description

Prestressed Connected Concrete Beam Circular Concrete Steel Tube Column Joints

technical field

The invention relates to a joint of a prestressed connected concrete beam circular steel pipe concrete column and belongs to the technical field of building structures.

Background technique

Concrete filled steel tubes have been used in construction projects for more than 100 years. Because of its high bearing capacity, good plasticity and toughness, good economic effect and convenient construction, the circular steel pipe concrete has been valued by the engineering field. Circular concrete filled steel tubes can adapt to the needs of modern engineering structures to develop towards large spans, high towers, heavy loads and withstand harsh conditions, and meet the industrial requirements of modern construction technology, so they are being more and more widely used in single-story and multi-story industrial factory building columns , Equipment frame columns, trestle columns, piles, space structures, commercial plazas, multi-storey office buildings and residences, high-rise and super high-rise buildings, and bridge structures have achieved good economic and architectural effects. Especially in recent years, the development of circular concrete-filled steel tube structures in our country is extremely rapid, and there are more and more researches on circular steel tube concrete structures.

The joints between circular concrete-filled steel tube columns and beams are one of the key issues in the design of concrete-filled steel tubes. The effectiveness of the joints directly affects the stiffness, stability and bearing capacity of the overall structure, and also affects the difficulty and progress of on-site construction. . Existing concrete-filled steel tube joints come in various forms, most of which are complex in structure, difficult in construction, unclear in force transmission, and unclear in joint calculation models. Up to now, there is still no complete set of joint calculation theory and design methods in our country. Therefore, it is very necessary to develop a new, safe and reliable joint form of circular CFST columns and beams.

The construction method of bonded prestress, through the grouting of the tunnel, makes the prestressed tendon and concrete bond with each other, reduces the effect of the anchorage on the transfer of prestress, improves the reliability and durability of anchorage, and is widely used in main load-bearing components or structures .

Contents of the invention

The purpose of the present invention is to provide a joint of prestressed concrete beams with circular concrete-filled steel tube columns. On the premise of ensuring effective joint connection and clear force transmission, by improving the joint connection mode between reinforced concrete beams and circular steel tube concrete columns, the prestressed joints are adopted. The stress tendons are assembled, which reduces the construction difficulty and speeds up the construction progress. The invention has fast construction speed, can effectively increase the shear bearing capacity of nodes, enhance its connection performance, and has broad application prospects.

In order to achieve the above object, the technical solution adopted by the present invention is a prestressed connected concrete beam circular steel tube concrete column node, as shown in Figures 1 and 2, including a circular steel tube concrete column (1) and a reinforced concrete beam (2), two The whole is composed of prestressed tendons; the round concrete-filled steel tube column (1) and the reinforced concrete beam (2) are cast-in-situ; the round concrete-filled steel tube column and the reinforced concrete beam (2) are connected by prestressed tendons; ) and the reinforced concrete beam (2) are left with a channel, and the metal bellows (4) is pre-embedded in the channel; the ring plate (5) is welded at the joint between the circular steel pipe concrete and the beam, and the ring plate (5) has a corresponding hole; channel steel (6) is welded on the round steel pipe.

The ring plate (5) is an ordinary steel plate, the width is the height of the beam section, and the thickness is the wall thickness of the steel pipe.

The height of the web of the channel steel (6) is the width of the beam section, the width of the flange is the height of the beam section, and the length of the channel steel is the height of the beam section. The steel pipes make full contact.

The design principle of the prestressed size of the prestressed tendon (3) is: not only to ensure the friction and shear resistance of the connection, but also to keep the stress in the prestressed tendon within the yield limit.

The ring plate at the end of the side column can be used as a bearing plate when the prestressed steel bar (3) is stretched.

Compared with the prior art, the present invention has the following beneficial effects.

The site construction speed is fast by using this kind of node, and the reliability of node connection can be guaranteed. This kind of joint adopts ring plate, which can reduce the weakening of the bearing capacity when the round steel pipe is opened; the use of channel steel can increase the shear bearing capacity of the beam-column joint; the use of prestressed steel bars, through the hole grouting, make the prestressed tendons and concrete Mutual bonding reduces the prestressing effect of anchors and improves the performance of reinforced concrete beams, which brings huge economic benefits to my country's economic and social development, and has broad application prospects.

Description of drawings

Figure 1 is the elevation view of the middle node

Figure 2 is the elevation view of edge nodes

Fig. 3 is a sectional view along A-A of Fig. 1

Figure 4 is a cross-sectional view along B-B of Figure 2

Figure 5 is a sectional view along C-C of Figure 2

Figure 6 is a cross-sectional view along D-D of Figure 1

In the figure: 1, circular steel pipe concrete column, 2, reinforced concrete beam, 3, prestressed tendons, 4, metal bellows, 5, ring plate, 6, channel steel, 7, mortar.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1-6.

Example 1

The joint structure of the prestressed concrete beam circular concrete-filled steel tube column is shown in Figure 1:

1. Positioning of circular steel tube concrete

The steel pipes of the steel tube concrete columns (1) are drilled in strict accordance with the drawings in the steel structure processing plant; the ring plates (5) and channel steel (6) are welded by surrounding welding at the connecting beams of the circular steel tube concrete columns (1) ; The hoisting and positioning of the steel tube concrete column (1).

2. Binding beam reinforcement skeleton and prestressed reinforcement fixed

Support the beam bottom formwork, bind the beam steel skeleton strictly according to the design drawings; support one side of the side formwork, draw the metal bellows positioning line on the side formwork according to the position of the prestressed tendons given in the drawing, and weld them on the beam stirrups in turn The bellows fixing bracket is used to place the metal bellows (4).

3. There are bonded prestressed tendons

After the corrugated pipe is fixed, the anchor plate is installed at the anchoring end, and the prestressed tendon is smoothly inserted into the corrugated pipe from the anchoring end. The tension end leaks 0.8m, and the nozzle is plugged tightly with cement bag paper to prevent the cement slurry and curing water from flowing in, and the prestressed steel bar leaking out is wrapped with adhesive tape to prevent moisture from corroding the prestressed bar.

4. Concrete pouring

Pouring circular steel pipe concrete columns and reinforced concrete beams. For concrete pouring methods, see "Standards for Construction Technology of Concrete Engineering".

5. Tensioning of prestressed tendons

After the concrete strength reaches 85% of the design strength, the prestressed tendon is stretched. The tension adopts a symmetrical tension method, and the action line of the tension force coincides with the center line of the tunnel. The tension control adopts double control of stress and elongation value, and the tension program is 0→10%σ _con →100%σ _con →103%σ _con →anchor.

6. Hole grouting

Fill the tunnel with mortar (7) within 48 hours after the tensioning is completed, use 42.5R ordinary Portland cement for grouting, and keep consistent during the grouting process.

7. Cutting

After the tensioning is finished, use a portable grinder cutter to cut off the exposed prestressed tendons, and the exposed length should not be less than 1.5 times the diameter of the prestressed tendons, and not less than 30mm.

Example 2

When it is a side column node, see Figure 2. Other measures are the same as in Embodiment 1, except that the prestressed tendon is welded to the ring plate (5) at the end of the side column. pressure plate.

Claims (2)

1. a kind of prestressing force connects beams of concrete concrete-filled circular steel tube column node, it is characterised in that：The node is mixed including round steel pipe Solidifying earth pillar (1), reinforced beam (2), presstressed reinforcing steel (3), ring flat-plate (5) and channel-section steel (6)；Concrete-filled circular steel tube column is mixed with reinforcing bar Solidifying Tu Liang (2) is connected using presstressed reinforcing steel；Concrete-filled circular steel tube column (1) leaves duct with reinforced beam (2) junction, Built-in metal bellows (4) in duct；Concrete-filled circular steel tube column welds annulate lamella (5), ring flat-plate with reinforced beam junction (5) there is corresponding hole on；Channel-section steel (6) is welded in round steel pipe；Concrete-filled circular steel tube column (1) and reinforced beam (2) are existing Pour, presstressed reinforcing steel (3) uses bonded prestressed tendon；Ring flat-plate (5) is general steel plate, and width is beam section height, thickness It is thickness of steel pipe.

2. prestressing force according to claim 1 connects beams of concrete concrete-filled circular steel tube column node, it is characterised in that：Channel-section steel (6) web height is beam section width, and flange width is beam section height, and channel-section steel length is beam section height, the web of channel-section steel Cut into round steel pipe identical radian, during to weld with round steel pipe completely attach to.