A prefabricated bamboo-concrete composite frame beam-column joint

Abstract

This invention discloses a prefabricated bamboo-concrete composite frame beam-column joint, comprising bamboo fiber tube concrete columns and composite beams. During on-site assembly, an outer sleeve is inserted into the bamboo fiber tube at the joint area, and adhesive is injected for bonding. The bamboo beam and steel joint are then assembled to form the composite beam. Reliable connections between the bamboo fiber tube, the outer sleeve, and the steel joint are achieved using through bolts or single-sided bolts. Finally, concrete is poured into the tubes, and the structure is cured to form the final structure. The prefabricated composite beam-column joint components assembled by this invention are lightweight, high-strength, energy-saving, and emission-reducing. The resulting beam-column joint fully utilizes the material combination effect, minimizing cross-sectional dimensions and material usage while maximizing load-bearing and deformation capacity. On-site assembly requires minimal hoisting equipment and temporary supports, eliminating much of the formwork and finishing work required for the main structure. This achieves a "high-performance, low-cost, and easy-to-construct" composite structural system. The steel joints at the beam ends form a seismic-resistant beam hinge mechanism with strong energy dissipation capacity, ensuring outstanding seismic performance of the frame structure.

Description

(I) Technical Field

[0001] This invention relates to the field of building engineering, and in particular to a prefabricated bamboo-concrete composite frame beam-column joint. (II) Background Technology

[0002] In the dual-carbon strategy, achieving green construction is a key path for the green development of my country's construction industry, and green building materials are an important carrier for energy conservation and emission reduction throughout the construction process. Bamboo is a biomass material with excellent mechanical properties and high processability. With the development of industrial technology, bamboo produced in standardized factories can overcome the problems of large dispersion in bamboo cross-sectional dimensions and material strength. The resulting modern bamboo structure buildings have advantages such as high load-bearing capacity, good deformation performance, and beautiful exterior finish, and have gradually attracted widespread attention both domestically and internationally.

[0003] However, the current high construction cost of pure bamboo structures, exceeding that of steel and far surpassing that of concrete, is the biggest obstacle to their large-scale application. Joints are crucial in structural construction. To ensure the structure's seismic resistance and energy dissipation capacity, numerous metal connectors are required at component joints. This not only demands high precision in component processing and installation but also significantly reduces the effective cross-sectional area, necessitating larger cross-sectional dimensions. Furthermore, because engineered bamboo is composed of multiple layers of sheets or bundles bonded under high pressure, large-section components are prone to interlayer delamination failure under stress, failing to fully utilize the material's strength. (III) Summary of the Invention

[0004] The purpose of this invention is to address the problem that pure bamboo structures cannot balance cost and performance by proposing a prefabricated bamboo-concrete composite frame beam-column joint to achieve optimal seismic performance and the lowest construction cost and energy consumption, thereby realizing efficient prefabricated construction of the overall structure and promoting the high-quality development of green buildings.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A prefabricated bamboo-concrete composite frame beam-column joint includes a bamboo fiber tube concrete column and a composite beam. The bamboo fiber tube concrete column comprises a bamboo fiber tube, internal concrete, and an outer casing for the joint area. The bamboo fiber tube is wrapped with bamboo fiber and bonded layer by layer to the core tube using a winding process. Openings are made at the joint connections of the bamboo fiber tubes, with the opening size matching the opening dimensions of the outer casing and the steel joint end plate. The internal concrete is divided into multiple sections according to height after the bamboo fiber tube, the outer casing, and the steel joint are connected. Pouring and vibration; the outer sleeve of the node area is a pipe with an inner diameter slightly larger than the outer diameter of the bamboo fiber pipe, and its inner wall is bonded to the outer wall of the bamboo fiber pipe node area. The pre-pressure during the curing process of the adhesive is provided by the pre-tightening force of the bolts on the end plate of the steel joint; the composite beam includes an engineering bamboo beam and a steel end; the end of the engineering bamboo beam has a pre-grooved opening, the width of which is slightly larger than the thickness of the web of the steel joint, and a reserved opening is provided for connection with the bolts on the web of the steel joint; the steel joint is welded from an arc-shaped end plate, an upper flange plate, a lower flange plate, a web plate, and a stiffening plate.

[0007] Preferably, the inner wall of the bamboo fiber tube can be treated with a sand coating or bonded shear connectors to enhance the bonding performance with the concrete inside the tube.

[0008] Preferably, the outer diameter of the bamboo fiber tube should not exceed 600 mm;

[0009] Preferably, the overlapping area between the outer wall of the bamboo fiber tube and the inner wall of the outer sleeve in the node area can be treated with a sand coating to enhance the bonding performance between the two.

[0010] Preferably, the connection between the steel joint and the outer sleeve and bamboo fiber tube of the node area should be completed before the adhesive at the bonding interface of the latter two hardens.

[0011] Preferably, when the steel joint is connected to the outer sleeve and bamboo fiber tube of the node area using through bolts, in order to avoid collision between bolts in two horizontal orthogonal directions, it can be partially replaced with single-sided bolt connection.

[0012] Preferably, the engineered bamboo beams can be made from bamboo laminated timber or reconstituted bamboo.

[0013] Preferably, the cross-sectional shape of the bamboo beam in the project is rectangular, and the height does not exceed 600mm;

[0014] Preferably, the concrete inside the pipe is non-shrink concrete or concrete with a micro-expansion agent added;

[0015] Preferably, longitudinal reinforcement bars can be arranged in the concrete inside the pipe according to the load-bearing requirements;

[0016] The beneficial effects of this invention are as follows: This invention achieves the green design goals of high performance, low cost, and easy construction of the overall structure; the frame columns, combined with high-strength bamboo fiber tubes, strongly constrain the concrete inside the tubes, reducing cross-sectional dimensions and thus significantly reducing material usage; the lightweight tubes facilitate transportation and hoisting, and as permanent formwork, they are easy to pour concrete into, while the aesthetically pleasing exterior finish simplifies the amount of finishing work; the ends of the frame beams are steel joints with strong energy dissipation capacity, forming a beam hinge mechanism that significantly improves the overall structure's seismic performance and collapse resistance; the mid-span area of ​​the frame beams is made of engineered bamboo, requiring only consideration of vertical load-bearing safety, effectively controlling cross-sectional dimensions, significantly reducing the construction cost of engineered bamboo, and facilitating on-site assembly; the overall frame structure extensively uses low-energy-consumption, low-carbon-emission biomass bamboo, ensuring green construction. (iv) Description of the attached drawings

[0017] Figure 1 This is a schematic diagram of the beam-column joint of the prefabricated bamboo-concrete composite frame of the present invention.

[0018] Figure 2 This is a schematic diagram of the connection between the bamboo fiber tube and the steel joint of the present invention based on the through bolt.

[0019] Figure 3 This is a schematic diagram of the connection between the bamboo fiber tube and the steel joint of the present invention based on a single-sided bolt.

[0020] Figure 4 This is a schematic diagram of the composite beam of the present invention.

[0021] Figure 5 This is a schematic diagram showing the connection between the engineering bamboo beam and the steel joint of the present invention.

[0022] Figure 6 This is a schematic diagram of the steel joint of the present invention.

[0023] Among them are: 1- Bamboo fiber tube concrete column; 2- Composite beam; 3- Bamboo fiber tube; 4- Concrete inside the tube; 5- Outer tube of the joint area; 6- Engineering bamboo beam; 7- Steel joint; 8- Through bolt; 9- Single-sided bolt; 10- High-strength bolt; 11- Groove; 12- Arc-shaped end plate; 13- Upper flange plate; 14- Lower flange plate; 15- Web plate; 16- Transverse stiffening plate. (V) Detailed Implementation

[0024] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0025] This invention provides a prefabricated bamboo-concrete composite frame beam-column joint, comprising a bamboo fiber tube concrete column 1 and a composite beam 2. Prefabricated bamboo fiber tubes 3, joint area outer sleeves 5, engineered bamboo beams 6, and steel joints 7 are transported to the site and hoisted to the construction floor. During the beam-column joint assembly stage, the bamboo fiber tubes 3 are placed at the positioning points, and the distance between adjacent fiber tubes 3 is determined. The web 15 of the steel joint 7 is embedded into the groove 11 at the end of the engineered bamboo beam 6, and the composite beam 2 is formed by connecting it with high-strength bolts 10. The longitudinal length of the composite beam 2 is fine-tuned according to the measured distance between the two bamboo fiber tubes 3. Temporary brackets are pre-set below the actual installation location of the composite beam 2 at its longitudinal trisection points or mid-span to facilitate subsequent assembly operations of the composite beam 2. The joint area outer sleeve 5 is fitted onto the bamboo fiber tube 3 and fixed to the connection with the steel joint 7, and adhesive is injected into its inner wall. Before the adhesive hardens, the bamboo fiber tube 3, the joint area outer sleeve 5, and the composite beam 2 are connected by bolts. The bolts can be either through bolts 8 or single-sided bolts 9. Pre-tightening force is applied to the bolts at the arc-shaped end plate 12 of the steel joint 7 to ensure a tight bond between the adhesive interface of the bamboo fiber tube 3 and the joint area outer sleeve 5. Finally, the concrete 4 inside the tube is poured directly without formwork, and the beam-column joint is cured.

[0026] The bamboo fiber pipe 3 is a standardized industrial biomass pipe based on bamboo fiber winding molding, which has been disclosed in relevant prior art inventions and will not be repeated here. The outer sleeve 5 of the node area uses the same pipe material as the bamboo fiber pipe 3, and its inner diameter is 2-3 mm larger than the outer diameter of the bamboo fiber pipe 3. Its height is not less than twice the height of the arc-shaped end plate 12 of the steel joint 7 plus its own thickness.

[0027] The width of the end slot 11 of the bamboo beam 6 in the project is 1-2 mm greater than the thickness of the web plate 15 of the steel joint 7, and a hole should be drilled in advance at the connection with the web plate 15, with the hole size being 1-1.5 mm larger than the diameter of the high-strength bolt 10.

[0028] The steel joint 7 is welded from an arc-shaped end plate 12, an upper flange 13, a lower flange 14, a web plate 15, and a transverse stiffening plate 16. The outline of the arc-shaped end plate 12 is consistent with the outer diameter of the outer sleeve of the node area. Holes are pre-drilled on the arc-shaped end plate 12 and the web plate 15, and the size of the holes is 1 to 1.5 mm larger than the diameter of the bolts used.

[0029] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all fall within the protection scope of the present invention.

Claims

1. A prefabricated bamboo-concrete composite frame beam-column joint, comprising a bamboo fiber tube concrete column (1) and a composite beam (2), characterized in that: During the transportation and hoisting stages, the concrete inside the pipe (4) is not poured. During the assembly stage, the bamboo fiber pipe (3) is positioned and installed first. The bamboo beam (6) and steel joint (7) are assembled on site to form a composite beam (2). The longitudinal length of the composite beam is slightly adjusted according to the actual distance between the pipes. Then, the outer sleeve (5) of the node area is inserted into the bamboo fiber pipe (3), and adhesive is injected into the inner wall of the outer sleeve (5) of the node area. The outer sleeve (5) of the node area uses the same pipe material as the bamboo fiber pipe (3). Its inner diameter is 2-3mm larger than the outer diameter of the bamboo fiber pipe (3). Its height is not less than the height of the arc end plate (12) of the steel joint (7) plus twice its own thickness. It is bolted to the arc end plate (12) of the steel joint (7) at the end of the composite beam (2). The pre-tightening force of the bolts ensures that the adhesive interface is tightly attached. The concrete inside the pipe (4) is poured and cured until the structure is formed.

2. The prefabricated bamboo-concrete composite frame beam-column joint according to claim 1, characterized in that: The bolted connection between the composite beam (2) and the bamboo fiber tube concrete column (1) and the joint area outer sleeve (5) should be completed quickly after the adhesive is injected to ensure the integrity of the bamboo fiber tube concrete column (1) and the joint area outer sleeve (5).

3. The prefabricated bamboo-concrete composite frame beam-column joint according to claim 1, characterized in that: The width of the end slot (11) of the bamboo beam (6) of the project is 1-2 mm greater than the thickness of the web plate (15) of the steel joint (7), and a hole should be drilled in advance at the connection with the web plate (15), with the hole size being 1-1.5 mm larger than the diameter of the high-strength bolt (10).

4. The prefabricated bamboo-concrete composite frame beam-column joint according to claim 1, characterized in that: The steel joint (7) is welded from an arc-shaped end plate (12), an upper flange (13), a lower flange (14), a web plate (15), and a transverse stiffening plate (16). The outline of the arc-shaped end plate (12) is consistent with the outer diameter of the outer sleeve of the node area. Holes are pre-drilled on the arc-shaped end plate (12) and the web plate (15), and the size of the holes is 1 to 1.5 mm larger than the diameter of the bolts used.

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