CN115341714A - Fabricated hybrid beam with steel pipe concrete structure as connecting node and method - Google Patents

Abstract

The invention discloses an assembled composite beam with a steel pipe concrete structure as a connecting node and a method thereof. The prefabricated mixed beam includes the prefabricated unit of the mixed beam and the connection structure with the assembled mixed column; the middle section of the prefabricated unit of the mixed beam is a reinforced concrete beam, and steel pipe components are arranged at the left and right ends. Cohesion; the extended section of the steel pipe assembly passes through the butt column corbel and pours self-compacting concrete into the steel pipe cavity to make the prefabricated unit of the mixed beam and the assembled mixed column realize the strong connection of the steel pipe concrete structure; the construction method includes the prefabricated unit of the assembled mixed beam The factory-made and fabricated hybrid beam prefabricated units are assembled on site. The prefabricated composite beam structure of the present invention has superior mechanical performance, fast construction, mature and simple process, reliable and controllable quality, and obvious comprehensive cost-effective advantages.

Description

Prefabricated hybrid beam with steel tube concrete structure as connection node and method

technical field

The invention relates to a prefabricated concrete beam and a method for construction engineering, in particular to an assembled mixed beam with a steel tube concrete structure as a connecting node and a construction method thereof.

Background technique

The prefabricated structure not only occupies a fundamental position in the prefabricated building integrated system, but also plays a "vanguard" leading role in realizing the goal of building industrialization. At present, the prefabricated structure system is mainly composed of prefabricated concrete structure and prefabricated steel structure. Among them, prefabricated concrete structure technology has invested more in research and development in recent years and has made certain progress, but it is still far away from the quality, environmental protection, efficiency, cost and other control objectives. There is not a small gap. In terms of formulation of technical standards, the technical standards for prefabricated concrete have a relatively large impact on the scope of application of buildings, such as building height, seismic intensity, and key parts such as the reinforcement area at the bottom of the shear wall, the core tube, the embedded area of the upper structure, and the first floor columns. Many restrictions or strict requirements reflect a more cautious and scientific attitude towards the current prefabricated concrete structure technology; in terms of engineering application, the current prefabricated concrete structure is mainly based on the planar beam-slab system (secondary beam and floor) However, vertical structural systems such as assembled integral frame structure, assembled integral frame-shear wall structure and assembled integral shear wall structure are still rarely used, resulting in a low overall prefabrication rate and assembly rate of assembled concrete structures.

The current prefabricated concrete structure technology is generally divided around the technical path of "equivalent to cast-in-place". In terms of structural performance, the current prefabricated concrete structure can only be theoretically "infinitely close to cast-in-place". It is not easy to achieve "close to cast-in-place" in engineering practice.

Taking the assembly of integral concrete composite beams as an example, the beams and prefabricated components such as columns or walls are connected by technologies such as post-cast concrete and steel anchor plates. Rough surfaces should be provided, key grooves should be provided on the end surfaces of prefabricated beams and rough surfaces should be provided, and the shear bearing capacity of the vertical joints at the ends of composite beams should be checked and calculated. Weakened; in the prefabricated column composite beam frame joints, the longitudinal reinforcement of the lower part of the beam can only be anchored or connected in a limited post-casting area, especially the frame column top joints, which cannot be longitudinally stressed like the cast-in-place joints Adequate anchoring or connection of reinforcement. When installing prefabricated beams, it is necessary to adopt temporary support frames, temporary steel corbels or temporary fixing measures of both; beam-column joint areas need to take mold sealing measures; beam end stirrups of composite frame beams with seismic ratings of 1 and 2 When the overall closed stirrups are used, the longitudinal reinforcement on the upper part of the beam needs to pass through the closed stirrups, and the construction is more difficult; when the torsion-resistant prefabricated beams are arranged, the longitudinal reinforcement of the beam web needs to be extended and anchored by mechanical connection joints.

Compared with assembled integral concrete composite beams, steel-concrete fabricated hybrid beams (referred to as composite beams) have steel joints such as I-beams at both ends, and the beam-column joints can be connected by steel structures, which has the advantages of convenient construction and connection. It has the advantages of reliable quality, short construction period and low cost. Such nodes not only realize the standardization and modularization of building components in the factory, but also enable rapid assembly at the construction site, truly realizing standardized design, factory production and assembly construction. The current research results show that although the so-called connection transition section of the composite beam anchored into the reinforced concrete section adopts a steel-concrete composite structure, most of the connection sections are mainly pure steel structures, which brings about the attenuation of the stiffness of the composite beam end and the ductility of the joint structure. Insufficient and other problems, the mechanical performance can not reach the goal of "equivalent to cast-in-place".

In order to realize the design principle of "strong joints and weak members", ensure that the assembled parts of the beam-column joint area have sufficient strength, stiffness and ductility, and meet the requirements for bearing capacity and deformation capacity under normal use conditions and earthquake action, the present invention Based on the current design and construction technology, guided by the theory of steel-concrete composite structure, especially the theory of steel tube concrete, a new approach has been found in the connection between prefabricated composite beams and beams and wall columns, and creatively introduces steel tube concrete connection nodes. The performance is "higher than that of cast-in-place", and the assembled monolithic concrete structure is promoted to develop towards the direction of the fully assembled concrete structure.

Contents of the invention

In order to solve the problems existing in the background technology, the purpose of the present invention is to provide a steel-concrete fabricated composite beam with superior structural mechanical performance and good economical efficiency and a set of construction methods with mature technology, convenient installation and reliable connection, to solve the problem of Problems encountered in the design, construction and quality inspection of the current assembly of integral concrete composite beams or hybrid beams with pure steel structures as connecting sections; promote the realization of quality, environmental protection, efficiency, cost and other control objectives of prefabricated concrete structures .

The prefabricated composite beam structure of the present invention has superior mechanical performance, fast construction, mature and simple process, reliable and controllable quality, and obvious comprehensive cost-effective advantages.

To achieve the above object, the present invention adopts the following technical solutions:

1. A prefabricated composite beam with a steel tube concrete structure as a connecting node:

The prefabricated composite beam includes a composite beam prefabricated unit and a connection structure between the composite beam prefabricated unit and the fabricated composite column; the middle section of the composite beam prefabricated unit is a reinforced concrete beam, and the left and right ends of the composite beam prefabricated unit are respectively set Steel pipe assembly, part of the steel pipe assembly is embedded in the reinforced concrete beam as the inward extension, and the other part is protruded from the reinforced concrete beam as the outreach section. Variable section.

The reinforced concrete beam includes prefabricated unit concrete poured along the beam direction and upper corner bars, upper middle bars, lower corner bars, lower middle bars, longitudinal structural bars and stirrups embedded in the precast unit concrete; The upper two corners of the upper part are respectively provided with upper corner reinforcements, and the upper middle reinforcement is arranged between the two upper corner reinforcements of the upper two corners; The lower middle reinforcement; the longitudinal structural reinforcement is arranged between the upper corner reinforcement and the lower corner reinforcement on each side of the same side of the prefabricated unit concrete, and the outer circumference of the upper corner reinforcement and the lower corner reinforcement of the four corners is provided with stirrups; the precast unit concrete without steel pipe components In the middle, tie bars are set between the intersections of the stirrups on both sides and the longitudinal structural steel bars for connection.

The steel pipe assembly is formed by welding an upper flange plate, a lower flange plate, and webs arranged symmetrically on both sides in a rectangular shape; the upper flange plate, the lower flange plate, and the web of the steel pipe assembly The inner side of the plate is welded with shear studs; in the overhanging section of the steel pipe assembly, the lower flange plate is welded and fixed to the webs on both sides respectively, and the upper flange plate is displaced inwardly relative to the lower flange plate and the web, so that the overhanging The section forms a "U"-shaped opening section; in the inward section of the steel pipe assembly, the upper flange plate, the lower flange plate and the webs on both sides reduce the width of the steel plate, and the upper flange plate, the lower flange plate and the webs on both sides The end of the web embedded in the reinforced concrete beam is welded with stiffeners between adjacent two in the circumferential direction, so that a variable cross-section chamfering area is formed outside the stiffeners at the four corners of the inner extension section of the steel pipe assembly.

The upper corner bars and upper middle bars of reinforced concrete beams are welded to the upper flange plate of the steel pipe assembly; the lower corner bars and lower middle bars of the reinforced concrete beam are welded to the lower flange plate of the steel tube assembly; the longitudinal structure of the reinforced concrete beam Rebar is welded to the web of the steel tube assembly.

A feed conduit and an overflow conduit are respectively arranged in the variable-section chamfering area.

The connection structure between the prefabricated unit of the mixed beam and the column is specifically as follows: including setting the column corbel, the column corbel is mainly passed by the upper flange plate of the corbel, the lower flange plate of the corbel and the corbel webs arranged symmetrically on both sides The welding is enclosed by a rectangle, one end of the column corbel is welded to the fabricated hybrid column, and the other end is welded to the extension section of the steel pipe assembly of the composite beam prefabricated unit.

The upper flange plate of the corbel, the lower flange plate of the corbel and the corbel webs on both sides are respectively connected with the upper flange plate, the lower flange plate and the corbel webs of the steel pipe assembly extension section of the composite beam prefabricated unit. The web is correspondingly welded with groove welds, and the cavity of the column corbel and steel pipe assembly is poured with self-compacting concrete.

2. A construction method of a prefabricated composite beam:

The method includes the factory manufacturing process of the mixed beam prefabricated unit and the on-site assembly process of the prefabricated mixed beam.

The factory production process of the hybrid beam prefabricated unit:

step one:

Cut and chamfer the upper flange plate, lower flange plate and web of the steel pipe assembly, and weld the shear studs, and make bolt holes on the web for connecting the connecting plate for installation;

Step 2, the upper flange plate and the lower flange plate are welded to the web plate as the main materials, and the upper flange plate is retracted and shifted to form a rectangular steel pipe, and the upper flange plate, lower flange plate and Stiffeners are welded to the ends of the webs, and temporary fixing plates are welded between the tops of the webs on both sides of the steel pipe assembly's extended section;

Step 3, tying and making a reinforcement cage composed of upper corner bars, upper middle bars, lower corner bars, lower middle bars, longitudinal structural bars and stirrups, welding the upper corner bars, upper middle bars and upper flange plates, and lower The corner reinforcement, the lower middle reinforcement are welded to the lower flange plate, the longitudinal structural reinforcement is welded to the web, and the stirrups are arranged in full length;

Step 4, put the feed conduit and overflow conduit into the chamfering area with variable cross-section, and seal the nozzle;

Step 5, support the supporting steel formwork for concrete pouring of the prefabricated unit of the mixed beam, and insert the supporting steel formwork into the steel pipes at the left and right ends of the prefabricated unit;

Step 6, pour concrete into the cavity of the column corbel and the steel pipe assembly to form prefabricated unit concrete, and vibrate and compact it;

Step 7, demoulding after forming and maintenance to form a prefabricated composite beam unit;

Step 8: Spot-weld backing plates for welding at the ends of the upper flange plate and the lower flange plate at the extended section of the steel pipe assembly of the hybrid beam prefabricated unit, and complete the factory manufacturing process of the hybrid beam prefabricated unit.

On-site assembly process of the prefabricated hybrid beam:

Step 1. Complete the installation of the prefabricated hybrid column and its column corbel in advance. The corbel lower flange plate and corbel web in the column corbel are welded to the prefabricated hybrid column, and the corbel upper flange plate is not welded temporarily. Temporary fixing plates are welded and fixed on the top of the corbel web on both sides, and the corbel web is connected to one side of the connecting plate for installation with bolts for installation;

Step 2, transporting the finished composite beam prefabricated unit to the construction site;

Step 3: Lift the prefabricated unit of the mixed beam, align the web of the steel pipe assembly with the web of the corbel of the column corbel, and connect the connecting plate for installation with the web of the steel pipe assembly by tightening the installation bolts, so that the prefabricated unit of the mixed beam can be accurately placed position; then cut off the temporary fixing plates between the corbel webs on both sides and between the webs on both sides;

Step 4, between the web of the steel pipe assembly and the web of the corbel, the connecting plate for installation is used as the backing plate and correspondingly welded with groove welds;

Step 5, extend the welding torch from the opening of the "U" section of the steel pipe assembly's extended section, and use groove welds for corresponding welding between the lower flange plate of the corbel and the lower flange plate of the steel pipe assembly;

Step 6. Weld the two ends of the upper flange plate of the corbel with the upper flange plate of the assembled hybrid column and the steel pipe assembly respectively, and weld the upper flange plate of the corbel with the web plate of the corbel and the web of the steel pipe assembly. Plate welding to form a rectangular steel pipe connection cavity within the column corbel and steel pipe assembly;

Step 7, repeat steps 3, 4, 5, and 6 to complete the assembly and welding of all composite beam prefabricated units and composite column corbels;

Step 8, inject self-compacting concrete into the cavity of the rectangular steel pipe through the feed conduit, and stop injecting when the overflow conduit overflows the concrete;

Step 9: The self-compacting concrete to be poured reaches the design strength, and after passing the inspection, cut off the exposed feed conduit and overflow conduit, and complete the on-site construction process of all assembled composite beams.

According to the theory of steel-concrete composite structure, the composite structure can give full play to the mechanical properties of the two materials through reasonable combination and collocation, and obtain more superior structural performance; The interaction in the force process, that is, the confinement effect of the steel pipe on its core concrete, puts the concrete under a complex stress state, so that the strength of the concrete can be improved, and the plasticity and ductility properties can be improved; at the same time, due to the existence of concrete, it can delay or avoid Premature local yielding of steel pipes can ensure the full play of its material properties. The two materials of steel pipe concrete make up for each other's weaknesses, and at the same time give full play to each other's strengths, so that steel pipe concrete members have higher bearing capacity. Both are higher than the sum of the individual bearing capacity of steel pipes and core concrete that make up CFST. The theory of CFST structure has been verified through a large number of structural tests and has been widely used in engineering practice.

The prefabricated composite beam with the steel tube concrete structure as the connecting node in the present invention can be defined as: a steel-concrete composite beam with steel tube concrete at both ends and an effective connection with the middle reinforced concrete section. According to the different forces and materials, the composite beam can be divided into steel pipe concrete connection section, steel-concrete composite transition section, reinforced concrete section and so on. The concrete-filled steel tube connecting section is effectively combined with the inner concrete through the outer rectangular steel pipe through the shear bolt; The nails, stiffeners and concrete are effectively combined, and the continuity and transition of the stressed steel bars are ensured through batch welding of the upper and lower steel bars and longitudinal structural steel bars of the beam and the upper and lower flange plates and webs. The transition section not only solves the problem of connecting steel pipes At the same time, it slows down the sudden change in stiffness when transitioning from the steel tube concrete connection section to the reinforced concrete section; the reinforced concrete section does not contain steel bones, which is no different from reinforced concrete.

Compared with the integral concrete composite beam assembled with the same section or the hybrid beam with pure steel structure as the connecting section, the composite beam according to the present invention, because the connecting section is a steel tube concrete structure, is used for bending, shearing and torsion. Not only will it not be weakened, but it can also be strengthened by adjusting the thickness of the flange plate and web plate of the steel pipe, which has better structural rigidity, bearing capacity and resistance to deformation; in terms of structure, the upper flange plate of the connecting section is a joint-spanning The cover plate is misaligned with the joints of the lower flange plate and web plate, and the self-compacting concrete injected twice, the construction joint and the butt weld of the steel pipe at the junction of the new and old concrete are also misplaced, that is, there is a whole piece of steel plate on the outside of the concrete construction joint , there is integral pouring concrete on the inside of the butt weld of the steel plate, and these two kinds of staggered joints can make up for the construction defects and strengthen the reliability of the connection; therefore, both in theory and practice, it can be guaranteed that the connection performance of the composite beam can be higher than that of cast-in-place reinforced concrete beam.

Another important advantage of the present invention is reflected in the construction of the prefabricated mixed beam. From the factory production of the prefabricated unit of the mixed beam, the on-site hoisting and splicing of the prefabricated unit of the mixed beam, to the formation of the assembled mixed beam, conventional construction is adopted Technical and conventional detection means to ensure the construction quality of prefabricated composite beams.

The welding of the steel components at both ends of the prefabricated unit of the mixed beam, the double-sided or single-sided welding of the steel bar and the flange plate of the steel pipe, the web, the binding and spot welding of the steel skeleton in the prefabricated unit, the formwork, and the pouring of concrete are very mature. The construction technology and testing methods of the mixed beam prefabricated unit are hoisted and spliced on site using the connecting plate and bolts for installation to connect the corbel web and the steel pipe component web of the mixed beam prefabricated unit to ensure the accurate positioning of the mixed beam prefabricated unit , the upper flange plate of the corbel is a spanning cover plate, after the welding of the lower flange plate is completed, the welding is carried out to avoid the upper welding of the lower flange plate, the steel pipe assembly of the upper and lower flange plates of the corbel, the web and the prefabricated unit of the composite beam The upper and lower flange plates and webs are butt welded by groove welding, which is a commonly used construction method for box-shaped steel beams; pouring self-compacting concrete in the steel tube cavity is a common construction method for steel tube concrete structures; therefore, the complete construction of prefabricated hybrid columns The process is mature, simple, even plain, with strong controllability and high reliability. Compared with the current prefabricated concrete structure technology, there is no need for support, no need for calibration steel bars, and no complex connection processes such as sleeve grouting, grout-anchor lap joints, and joint grouting.

The construction period can be greatly shortened by using the prefabricated hybrid beam. After the steel pipe assembly of the prefabricated unit of the hybrid beam is butt welded with the column corbel, it already has a certain structural rigidity and bearing capacity, and the prefabricated unit of the hybrid beam can be completed first from bottom to top. Assembled and welded, the self-compacting concrete in the steel pipe cavity is poured and the conduit is cut before the precast floor is laid. That is to say, similar to the composite beam with pure steel structure as the connecting section, it bears the structural self-weight and construction load during installation, and there is no need to wait for the self-compacting concrete in the steel pipe cavity to reach the design strength before subsequent construction.

The prefabricated composite beam has good economy and higher comprehensive cost performance. Compared with the current prefabricated integral frame beam, the amount of steel used will increase because the prefabricated hybrid beam contains some steel tube concrete composite connection nodes. However, it can be known from the theory of steel pipe concrete that the comparison condition of meeting the same performance target is that the material used for steel pipe concrete is the most economical; specific to the fabricated composite beam of the present invention, there is no need for support, sleeve grouting, grout-anchor lap joint, joint grouting, etc. The complex connection process can save part of the material and construction costs, especially the shorter construction period and higher construction efficiency, which can save a lot of financial costs and labor costs; comprehensively considering the price factors such as materials, labor and construction period, the prefabricated hybrid The beam is more cost-effective than the current assembled integral frame beam.

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

Guided by the theory of steel-concrete composite structure, especially the theory of steel pipe concrete, the present invention finds a new way to connect the prefabricated concrete beam and column, creatively introduces the steel pipe concrete structure as the connection node, and solves the technical problems of the current prefabricated concrete beam.

The invention is a prefabricated hybrid beam with steel pipe concrete connection nodes, which can be applied to the current prefabricated concrete structures, such as prefabricated frame structures, prefabricated frame-shear wall structures, etc.; it can also be used for prefabricated concrete frame-core tube structures , prefabricated tube-in-tube structure and other super high-rise buildings.

Innovation point and beneficial effect of the present invention are:

1. The steel pipe component 2 of the prefabricated unit of the prefabricated mixed beam is butt-welded with the corbel of the mixed column to form a rectangular steel pipe, and self-compacting concrete is poured into the cavity of the rectangular steel pipe to make the connection between the assembled mixed beam and the assembled mixed column The section becomes a steel tube concrete structure, so it has better structural rigidity, bearing capacity and resistance to deformation, and can achieve the goal of "better than cast-in-place".

2. In terms of the structural measures of the inner extension section of the steel pipe assembly 2, the section of the upper flange plate 2.1, lower flange plate 2.2 and web plate 2.3 becomes smaller, which not only makes the upper reinforcement bars 1.1 and 1.2 of the reinforced concrete beam, and the lower Steel bars 1.3 and 1.4 and longitudinal structural steel bar 1.5 can be cut off and welded in batches, and the degree of sudden change in stiffness from the inner extension section to the reinforced concrete section can be reduced. In addition, with the assistance of stud 2.5 and stiffener 2.4, the inner extension section of the steel pipe assembly 2 can be connected with the The connection of reinforced concrete is firm and smooth, ensuring the overall performance of the prefabricated composite beam.

3. The steel pipe component 2 of the prefabricated unit of the prefabricated mixed beam is installed in place through the connecting plate 5 and the bolt 6 for installation, without the support system Fast and high precision installation.

4. Through the retreat of the upper flange plate 2.1 of the steel pipe assembly 2, a "U"-shaped cross-sectional opening is left, which facilitates the welding of the lower flange plate 2.2 of the steel pipe assembly 2 and the lower flange plate 3.2 of the corbel, avoids overhead welding, and reduces construction difficulty , to ensure the welding quality; the corbel upper flange plate 3.1 as a "cover plate" and post-cast self-compacting concrete both span the joint between the web plate and the lower flange plate to strengthen the reliability of the construction of the joint.

5. Use the space in the chamfering area of the variable cross-section of the inner extension of the steel pipe assembly 2 to place the feed conduit 9 and the overflow conduit 10 to realize the pouring of self-compacting concrete in a convenient manner. There is almost no "wet operation" on site, and the working environment is good.

6. Since most of the prefabricated units of the prefabricated composite beam are ordinary reinforced concrete materials, only some steel parts are included at both ends, so the material consumption is between the prefabricated reinforced concrete composite beam and the prefabricated steel beam, close to the prefabricated steel bar Material usage for concrete composite beams.

7. Since steel parts have few exposed surfaces and are box-shaped, anti-corrosion and fire-resistant materials can be sprayed or wiped directly, and the amount of coating work is small.

In general, the prefabricated composite beam of the present invention has superior mechanical properties, economical materials, reliable and controllable quality, efficient and convenient construction, and a good working environment. Connecting composite beams have a higher comprehensive cost performance. When used in conjunction with prefabricated composite columns or prefabricated composite column walls, it can greatly improve the assembly rate or prefabrication rate index of the structure, and has great market promotion value.

Description of drawings

Figure 1 is a schematic diagram of the prefabricated unit structure of the hybrid beam.

Figure 2 shows the connection between the hybrid beam and the hybrid column with corbels.

Fig. 3 is the section A-A of Fig. 1 .

Fig. 4 is a B-B section of Fig. 1 .

Fig. 5 is a C-C section of Fig. 1 .

FIG. 6 is a D-D section of FIG. 1 .

Fig. 7 is the section E-E of Fig. 2 .

FIG. 8 is the F-F section of FIG. 2 .

Fig. 9 is a section G-G of Fig. 2 .

Reference signs:

1 Prefabricated unit concrete, 1.1 Upper corner bars, 1.2 Upper middle bars, 1.3 Lower corner bars, 1.4 Lower middle bars, 1.5 Longitudinal structural bars, 1.6 Stirrups, 1.7 Tension bars;

2 Steel pipe components, 2.1 Upper flange plate, 2.2 Lower flange plate, 2.3 Web plate, 2.4 Stiffener, 2.5 Shear studs, 2.6 Bolt holes;

3 Assembled mixed column, 3.1 Corbel upper flange plate, 3.2 Corbel lower flange plate, 3.3 Corbel web;

4 temporary fixing plate, 5 connecting plate for installation, 6 bolt for installation, 7 backing plate for welding, 8 groove weld, 9 feed conduit, 10 overflow conduit, 11 self-compacting concrete.

Detailed ways

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

The invention is also a connection node of a steel pipe concrete structure using an assembled mixed beam, and connects the assembled mixed beam and a concrete column.

The prefabricated composite beam includes the prefabricated unit of the composite beam and the connection structure between the prefabricated unit of the composite beam and the column.

The prefabricated unit of the mixed beam is shown in Figure 1. The middle section of the prefabricated unit of the mixed beam is a reinforced concrete beam, and the cross section of the reinforced concrete beam is shown in Figure 3. Each of the two ends is connected to the steel pipe assembly 2, and a part of the steel pipe assembly 2 is buried in the reinforced concrete beam as an inward extension, and the other part is protruded from the reinforced concrete beam as an extension section. The cross-section is changed between the extension section and the overhang section.

Reinforced concrete beams include prefabricated unit concrete 1 poured along the beam direction and upper corner bars 1.1, upper middle bars 1.2, lower corner bars 1.3, lower middle bars 1.4, longitudinal structural bars 1.5 and stirrups 1.6 buried in the precast unit concrete 1 ; As shown in Figure 5, the upper two corners of the prefabricated unit concrete 1 are respectively provided with upper corner bars 1.1 along the beam direction, and two upper middle bars 1.2 are arranged between the two upper corner bars 1.1 of the upper two corners, and the upper corner bars 1.1 It is located on the same line as the upper middle reinforcement 1.2; the lower two corners of the prefabricated unit concrete 1 are respectively provided with the lower corner reinforcement 1.3 along the direction of the beam, and two lower middle reinforcement bars 1.4 are arranged between the two lower corner reinforcements 1.3 of the upper two corners, and the lower The corner reinforcement 1.3 and the lower middle reinforcement 1.4 are located on the same straight line; the longitudinal structural reinforcement 1.5 is arranged between the upper corner reinforcement 1.1 and the lower corner reinforcement 1.3 on each side of the prefabricated unit concrete 1, and the upper corner reinforcement 1.1 and the lower corner reinforcement of the four corners 1.3 Stirrups 1.6 are arranged on the outer periphery, upper corner bars 1.1, upper middle bars 1.2, lower corner bars 1.3, lower middle bars 1.4 and longitudinal structural bars 1.5 are all welded to the stirrups 1.6.

In the prefabricated unit concrete 1 without the steel pipe assembly 2, tie bars 1.7 are arranged between the intersections of the stirrups 1.6 on both sides and the longitudinal structural steel bars 1.5 for connection. Lajin 1.7 can be set optionally, and the quantity is optional. At the intersection, the stirrup 1.6, the longitudinal structural reinforcement 1.5, and the tie bar 1.7 are welded.

The steel pipe assembly 2 is formed by welding an upper flange plate 2.1, a lower flange plate 2.2, and webs 2.3 symmetrically arranged on both sides in a rectangular enclosure, as shown in FIG. 5; the upper flange plate 2.1 of the steel pipe assembly 2, The inner sides of the lower flange plate 2.2 and the web plate 2.3 are welded with shear studs 2.5.

In the extended section of the steel pipe assembly 2, the lower flange plate 2.2 is welded and fixed to the web plates 2.3 on both sides respectively, and the upper flange plate 2.1 is displaced inwardly relative to the lower flange plate 2.2 and the web plate 2.3, so that the extended section forms a " U”-shaped opening section, as shown in Figure 6; internal displacement means that the upper flange plate 2.1 moves toward the center of the reinforced concrete beam relative to the lower flange plate 2.2 and web plate 2.3, so that its position is the same as that of the lower wing The edge plate 2.2 and the web plate 2.3 are misaligned.

In the inner extension section of the steel pipe assembly 2, the upper flange plate 2.1, the lower flange plate 2.2 and the web plates 2.3 on both sides have a uniform cross-section, and the chamfering reduces the width of the steel plate. The upper flange plate 2.1, the lower flange plate 2.2 and the The webs 2.3 on both sides are welded with stiffeners 2.4 between the adjacent two in the circumferential direction at the ends of the embedded reinforced concrete beams, as shown in Figures 1 and 4, so that the four corners of the inner extension of the steel pipe assembly 2 A variable section chamfering area is formed outside the stiffener 2.4.

The upper corner bar 1.1 and the upper middle bar 1.2 of the reinforced concrete beam are welded with the upper flange plate 2.1 of the steel pipe assembly 2, and the upper middle bar 1.2 is welded with the upper flange plate 2.1 of the inner extension, as shown in Fig. 1 and Fig. 8 Shown; the lower corner reinforcement 1.3 and the lower middle reinforcement 1.4 of the reinforced concrete beam are all welded with the lower flange plate 2.2 of the steel pipe assembly 2, and the lower middle reinforcement 1.4 is welded with the lower flange plate 2.2 of the inner extension section, see Fig. 1, Fig. 9; the longitudinal structural reinforcement 1.5 of the reinforced concrete beam is welded to the web 2.3 of the steel pipe assembly 2.

Stirrups 1.6 are arranged around the inner extension of the steel pipe assembly 2, and no stirrups 1.6 are arranged around the outer extension of the steel pipe assembly 2.

Utilizing the space in the variable section chamfering area of the inner extension of the steel pipe assembly 2, a feed conduit 9 and an overflow conduit 10 are respectively arranged in the variable section chamfering area, as shown in Fig. 1 and Fig. 5 . Specifically, an overflow conduit 10 is provided at an upper corner of the variable-section chamfering area, and a feed conduit 9 is provided at a lower corner.

The connection structure between the composite beam prefabricated unit and the column is shown in Figure 2, specifically:

Including the setting of column corbels, the column corbels are mainly composed of the corbel upper flange plate 3.1, the corbel lower flange plate 3.2 and the corbel web 3.3 arranged symmetrically on both sides and surrounded by a rectangle by welding, the column corbel One end is welded with the fabricated hybrid column 3, and the other end is respectively welded with the extension section of the steel pipe assembly 2 of the composite beam prefabricated unit. One end of the corbel upper flange plate 3.1 close to the composite beam prefabricated unit is arranged to extend toward the composite beam prefabricated unit.

The inner sides of the upper corbel flange plate 3.1, the lower corbel flange plate 3.2 and the corbel web plate 3.3 are also welded with shear studs.

Corbel upper flange plate 3.1, corbel lower flange plate 3.2 and corbel web plates 3.3 on both sides are respectively connected with upper flange plate 2.1, lower flange plate 2.2 and The webs 2.3 on both sides are correspondingly welded with groove welds 8, and the column corbel formed by the corbel upper flange plate 3.1, the corbel lower flange plate 3.2 and the corbel webs 3.3 on both sides and the upper wing Self-compacting concrete 11 is poured into the cavity of the steel pipe assembly 2 formed by the flange plate 2.1, the lower flange plate 2.2 and the web plates 2.3 on both sides, as shown in Fig. 2 and Fig. 7 .

The web 2.3 of the steel pipe assembly 2 and the corbel web 3.3 of the column corbel are fixedly connected through the connecting plate 5 and bolts for installation.

The construction process of the present invention includes the factory production process of the composite beam prefabricated unit and the on-site assembly process of the prefabricated composite beam.

The present invention uses the steel tube concrete structure as the construction method of the assembled composite beam of connecting node, and its specific steps are as follows:

1) The factory production process of the composite beam prefabricated unit:

step one:

Cut and chamfer the upper flange plate 2.1, lower flange plate 2.2, and web 2.3 of the steel pipe assembly 2, and weld the shear studs 2.5 on the plates, and make them on the web 2.3 for connection and installation The bolt hole of connecting plate 5;

Prefabricated and processed stiffeners 2.4, plates for temporary fixing 4, connecting plates for installation 5, backing plates for welding 7, feed conduits 9, and overflow conduits 10 are classified and placed.

Step 2, the upper flange plate 2.1 and the lower flange plate 2.2 are welded to the web plate 2.3 as the main materials, and the upper flange plate 2.1 is retracted and shifted to form a rectangular steel pipe, and the upper flange plate 2.1 located in the inner extension of the steel pipe assembly 2 , The ends of the lower flange plate 2.2 and the web 2.3 are welded with upper stiffeners 2.4, and the temporary fixing plate 4 is welded between the tops of the webs 2.3 on both sides of the steel pipe assembly 2's extended section;

Step 3, tying and making a reinforcement cage consisting of upper corner bars 1.1, upper middle bars 1.2, lower corner bars 1.3, lower middle bars 1.4, longitudinal structural bars 1.5 and stirrup bars 1.6, and upper corner bars 1.1, upper middle bars 1.2 and The upper flange plate 2.1 is welded, the lower corner reinforcement 1.3, the lower middle reinforcement 1.4 are welded to the lower flange plate 2.2, the longitudinal structural reinforcement 1.5 is welded to the web 2.3, and the stirrup 1.6 is arranged along the entire length of the composite beam prefabricated unit;

Step 4, put the feed conduit 9 and the overflow conduit 10 into the variable section chamfering area, and seal the nozzle;

Step 5, support the supporting steel formwork for concrete pouring of the prefabricated unit of the mixed beam, and insert the supporting steel formwork into the steel pipes at the left and right ends of the prefabricated unit;

Step 6, pouring concrete into the cavity of the column corbel and the steel pipe assembly 2 to form the prefabricated unit concrete 1, and vibrating it for compaction;

Step 7, demoulding after forming and maintenance to form a prefabricated composite beam unit;

Step 8: Spot welding the backing plate 7 for welding on the end bottom surface of the upper flange plate 2.1 and the lower flange plate 2.2 at the extended section of the steel pipe assembly 2 of the hybrid beam prefabricated unit, completing the factory manufacturing process of the hybrid beam prefabricated unit.

2) On-site assembly process of prefabricated hybrid beams:

Step 1: Complete the installation of the prefabricated hybrid column 3 and its column corbel in advance. The corbel lower flange plate 3.2 and corbel web 3.3 in the column corbel are welded to the prefabricated hybrid column 3, and the corbel upper flange plate 3.1 No welding for now, the temporary fixing plate 4 is welded and fixed on the upper part of the corbel web 3.3 on both sides, and the corbel web 3.3 is connected to one side of the connecting plate 5 for installation with the bolt 6 for installation;

Step 2: Transport the finished composite beam prefabricated units to the construction site, classify and number them, and wait for installation;

Step 3, lifting the prefabricated unit of the mixed beam, aligning the web 2.3 of the steel pipe assembly 2 with the corbel web 3.3 of the column corbel, and connecting the connecting plate 5 for installation with the web 2.3 of the steel pipe assembly 2 by tightening the bolt 6 for installation, Make the prefabricated unit of the mixed beam accurately in place; cut off the temporary fixing plate 4 between the corbel webs 3.3 on both sides and between the webs 2.3 on both sides;

Step 4, between the web 2.3 of the steel pipe assembly 2 and the web 3.3 of the corbel, use the connecting plate 5 for installation as the backing plate and adopt the corresponding welding of the groove weld 8;

Step five, extend the welding torch from the opening of the "U" section of the extended section of the steel pipe assembly 2, and use groove welds 8 for corresponding welding between the lower flange plate 3.2 of the corbel and the lower flange plate 2.2 of the steel pipe assembly 2 ;

Step 6, weld the two ends of the upper flange plate 3.1 of the corbel to the upper flange plate 2.1 of the assembled hybrid column 3 and the steel pipe assembly 2 respectively, using the groove weld 8, and connect the upper flange plate 3.1 of the corbel to the belly of the corbel The plate 3.3 and the web plate 2.3 of the steel pipe assembly 2 are welded to form a rectangular steel pipe connection cavity in the column corbel and the steel pipe assembly 2;

Step 7, repeat steps 3, 4, 5, and 6 to complete the assembly and welding of the prefabricated unit of the mixed beam and the corbel of the mixed column;

Step 8, inject self-compacting concrete 11 into the cavity of the rectangular steel pipe through the feed conduit 9, and stop injecting when the overflow conduit 10 overflows the concrete;

Step 9: The self-compacting concrete 11 to be poured reaches the design strength, and after passing the inspection, the exposed feed conduit 9 and the overflow conduit 10 are cut off to complete the on-site construction process of the prefabricated composite beam.

Through specific implementation, it can be seen that the prefabricated composite beam of the present invention has superior mechanical performance, economical materials, reliable and controllable quality, efficient and convenient construction, and a good working environment. Steel-connected composite beams have a higher comprehensive cost performance. When used in conjunction with prefabricated composite columns or prefabricated composite column walls, it can greatly increase the assembly rate or prefabrication rate index of the structure, and has greater market promotion value.

Claims (10)

1. A prefabricated hybrid beam with a steel tube concrete structure as a connecting node, characterized in that: The prefabricated composite beam includes a composite beam prefabricated unit and a connection structure between the composite beam prefabricated unit and the fabricated composite column; the middle section of the composite beam prefabricated unit is a reinforced concrete beam, and the left and right ends of the composite beam prefabricated unit are respectively set A steel pipe assembly (2), a part of the steel pipe assembly (2) is embedded in a reinforced concrete beam as an inward extension, and the other part protrudes from the reinforced concrete beam as an outer extension and is connected through a column corbel and a prefabricated hybrid column. 2. A kind of prefabricated hybrid beam with steel pipe concrete structure as connection node according to claim 1, characterized in that: The reinforced concrete beam includes prefabricated unit concrete (1) poured along the direction of the beam, and upper corner bars (1.1), upper middle bars (1.2), lower corner bars (1.3) embedded in the precast unit concrete (1), The lower middle reinforcement (1.4), longitudinal structural reinforcement (1.5) and stirrup (1.6); the upper corners of the prefabricated unit concrete (1) are respectively provided with upper corner reinforcements (1.1), and the two upper corner reinforcements (1.1 ) between the upper middle reinforcement (1.2); the lower two corners of the prefabricated unit concrete (1) are respectively lower corner reinforcement (1.3), and the lower middle reinforcement (1.4 ); on both sides of the prefabricated unit concrete (1), a longitudinal structural reinforcement (1.5) is arranged between the upper corner reinforcement (1.1) and the lower corner reinforcement (1.3) of the same side, and the upper corner reinforcement (1.1) and the lower corner reinforcement (1.5) of the four corners ( 1.3) Stirrups (1.6) are set on the outer periphery; tie bars are set between the crossings of the stirrups (1.6) on both sides and the longitudinal structural steel bars (1.5) in the prefabricated unit concrete (1) without the steel pipe assembly (2) (1.7) to connect. 3. According to claim (1) or (2), a kind of prefabricated composite beam with steel pipe concrete structure as connection node, is characterized in that: The steel pipe assembly (2) is formed by welding the upper flange plate (2.1), the lower flange plate (2.2) and the webs (2.3) arranged symmetrically on both sides in a rectangular shape; the steel pipe assembly (2) The upper flange plate (2.1), the lower flange plate (2.2) and the inner side of the web plate (2.3) are all welded with shear studs (2.5); in the extended section of the steel pipe assembly (2), the lower flange The plates (2.2) are welded and fixed to the webs (2.3) on both sides respectively, and the upper flange plate (2.1) moves inwardly relative to the lower flange plate (2.2) and the web (2.3), so that the overhanging section forms a “U” shaped opening section; in the inner extension section of the steel pipe assembly (2), the upper flange plate (2.1), the lower flange plate (2.2) and the webs (2.3) on both sides reduce the width of the steel plate, and the upper flange plate (2.1 ), the lower flange plate (2.2) and the webs (2.3) on both sides are welded with stiffeners (2.4) between the ends of the embedded reinforced concrete beams in the circumferential direction, so that the steel pipe assembly (2 ) outside the stiffeners (2.4) at the four corners of the inner extension section to form a variable section chamfering area. 4. A kind of prefabricated hybrid beam with steel pipe concrete structure as connection node according to claim 3, characterized in that: the upper corner bar (1.1) and the upper middle steel bar (1.2) of the reinforced concrete beam are all connected with the steel pipe assembly ( 2) The upper flange plate (2.1) is welded; the lower corner bar (1.3) and the lower middle steel bar (1.4) of the reinforced concrete beam are welded with the lower flange plate (2.2) of the steel pipe assembly (2); the reinforced concrete beam The longitudinal structural reinforcement (1.5) is welded to the web (2.3) of the steel pipe assembly (2). 5. A prefabricated composite beam with a steel tube concrete structure as a connecting node according to claim 1, characterized in that: feed conduits (9) and overflow conduits (10) are respectively provided in the variable section chamfering area. 6. A prefabricated hybrid beam with a steel pipe concrete structure as a connection node according to claim 1, characterized in that: the connection structure between the prefabricated unit of the hybrid beam and the column is specifically: including setting column corbels, column The corbel is mainly composed of the corbel upper flange plate (3.1), the corbel lower flange plate (3.2) and the corbel web (3.3) which are symmetrically arranged on both sides and is enclosed in a rectangle by welding. One end of the column corbel It is welded with the prefabricated mixed column (3), and the other end is respectively welded with the extension section of the steel pipe assembly (2) of the mixed beam prefabricated unit. 7. A prefabricated hybrid beam with a steel pipe concrete structure as a connecting node according to claim 1, characterized in that: the upper corbel flange plate (3.1), the corbel lower flange plate (3.2) and the corbel webs (3.3) on both sides are respectively connected with the upper flange plate (2.1), the lower flange plate (2.2) and the webs (2.3 ) is correspondingly welded with groove welds (8), and self-compacting concrete (11) is poured into the cavities of the column corbel and the steel pipe assembly (2). 8. The construction method applied to any one of claims 1-7, characterized in that: The method includes the factory manufacturing process of the mixed beam prefabricated unit and the on-site assembly process of the prefabricated mixed beam. 9. The construction method of the prefabricated hybrid beam according to claim 8, characterized in that: The factory production process of the hybrid beam prefabricated unit: step one: Cut and chamfer the upper flange plate (2.1), lower flange plate (2.2) and web (2.3) of the steel pipe assembly (2), and weld the shear studs (2.5), web ( 2.3) Make bolt holes for connecting the connecting plate (5) for installation; Step 2, the upper flange plate (2.1) and the lower flange plate (2.2) are welded to the web plate (2.3) as the main materials, and the upper flange plate (2.1) is retracted and displaced to form a rectangular steel pipe, which is located in the steel pipe assembly (2 ) of the upper flange plate (2.1), lower flange plate (2.2) and web (2.3) of the inner extension section are welded with upper stiffeners (2.4), which are located on both sides of the outer extension section of the steel pipe assembly (2) The plate (4) for temporary fixing is welded between the tops of the plates (2.3); Step 3, tying and making a reinforcement cage consisting of upper corner bars (1.1), upper middle bars (1.2), lower corner bars (1.3), lower middle bars (1.4), longitudinal structural bars (1.5) and stirrups (1.6) , weld the upper corner bar (1.1), the upper middle bar (1.2) to the upper flange plate (2.1), weld the lower corner bar (1.3), the lower middle bar (1.4) to the lower flange plate (2.2), longitudinal The structural reinforcement (1.5) is welded to the web (2.3), and the stirrup (1.6) is arranged along the entire length; Step 4, put the feed conduit (9) and the overflow conduit (10) into the variable section chamfering area, and seal the nozzle; Step 5, support the supporting steel formwork for concrete pouring of the prefabricated unit of the mixed beam, and insert the supporting steel formwork into the steel pipes at the left and right ends of the prefabricated unit; Step 6, pour concrete into the cavity of the column corbel and the steel pipe assembly (2) to form prefabricated unit concrete (1), and vibrate and compact it; Step 7, demoulding after forming and maintenance to form a prefabricated composite beam unit; Step 8: Spot weld the backing plate (7) for welding at the end of the upper flange plate (2.1) and the end of the lower flange plate (2.2) at the overhanging section of the steel pipe assembly (2) of the mixed beam prefabricated unit, and complete the mixed beam Factory fabrication process for prefabricated units. 10. The construction method of the prefabricated composite beam according to claim 8, characterized in that: On-site assembly process of the prefabricated hybrid beam: Step 1: Complete the installation of the prefabricated hybrid column (3) and its column corbel in advance, the corbel lower flange plate (3.2), corbel web (3.3) and the prefabricated hybrid column (3) in the column corbel Welding, the corbel upper flange plate (3.1) is not welded temporarily, the temporary fixing plate (4) is welded and fixed on the upper part of the corbel web (3.3) on both sides, and the corbel web (3.3) adopts installation bolts (6 ) is connected to one side of the connecting plate (5) for installation; Step 2, transporting the finished composite beam prefabricated unit to the construction site; Step 3: Lift the prefabricated unit of the composite beam, align the web (2.3) of the steel pipe assembly (2) with the web (3.3) of the column corbel, and tighten the installation bolt (6) to connect the installation connecting plate (5) Connect with the web (2.3) of the steel pipe assembly (2), so that the prefabricated unit of the composite beam can be accurately positioned; then cut off the temporary Fixed plate (4); Step 4, between the web (2.3) of the steel pipe assembly (2) and the corbel web (3.3), use the connecting plate (5) for installation as a backing plate to weld correspondingly with the groove weld (8); Step 5, extend the welding torch from the opening of the "U" section of the extended section of the steel pipe assembly (2), and insert the welding torch between the lower flange plate (3.2) of the corbel and the lower flange plate (2.2) of the steel pipe assembly (2). Adopt groove weld (8) to weld correspondingly; Step 6. Weld the two ends of the upper flange plate (3.1) of the corbel with the upper flange plate (2.1) of the fabricated hybrid column (3) and the steel pipe assembly (2) respectively using groove welds (8), and the The leg upper flange plate (3.1) is welded to the corbel web (3.3) and the web (2.3) of the steel pipe assembly (2), forming a rectangular steel pipe connection cavity in the column corbel and steel pipe assembly (2); Step 7, repeat steps 3, 4, 5, and 6 to complete the assembly and welding of all composite beam prefabricated units and composite column corbels; Step 8, inject self-compacting concrete (11) into the cavity of the rectangular steel pipe through the feeding conduit (9), and stop injecting when the overflow conduit (10) overflows the concrete; Step 9: The self-compacting concrete (11) to be poured reaches the design strength, and after passing the inspection, the exposed feeding conduit (9) and the overflow conduit (10) are cut off, and the on-site construction process of all the assembled composite beams is completed.

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