Extrusion type double-layer aluminum alloy pipe lightweight concrete composite member and preparation method thereof

Abstract

The invention discloses an extrusion type double-layer aluminum alloy pipe lightweight concrete combined member and a preparation method thereof, the shape of a pipe body is as follows: the pipe body is formed by combining two concentric aluminum alloy pipes and stiffening ribs, a plurality of cavities are formed among an inner pipe, an outer pipe and the stiffening ribs, and the cavities are filled with lightweight concrete. Connection between the inner aluminum alloy pipe and the outer aluminum alloy pipe and the stiffening ribs does not need welding, the inner aluminum alloy pipe and the outer aluminum alloy pipe are integrally formed through an extrusion forming process, and the procedure of welding connection among the inner pipe, the outer pipe and the stiffening ribs is omitted. The inner pipe, the outer pipe and the stiffening ribs of the pipe body are made of the same aluminum alloy material, and 6-series or 7-series aluminum alloy can be adopted; according to the aluminum alloy, electrochemical corrosion caused by mixed use of different metal materials can be avoided, meanwhile, the corrosion resistance of the aluminum alloy is good, the later maintenance cost can be reduced, and the aluminum alloy is special in metal luster, attractive in appearance and free of additional decoration; the pipe is filled with foam concrete, lightweight aggregate concrete, aerogel concrete and other lightweight concrete, and the dead weight of the structure can be reduced.

Description

Technical Field

[0001] The present invention belongs to the field of civil engineering, and particularly relates to an extrusion-type double-layer aluminum alloy tube lightweight concrete composite member applied to the field of civil engineering and a preparation method thereof. Background Art

[0002] Aluminum alloy has the advantages of corrosion resistance, light self-weight, high specific strength, good durability, easy processing, maintenance-free, recyclable, etc. However, aluminum alloy also has disadvantages such as low elastic modulus, prominent structural stability problems, and relatively high material prices. Learning from the advantages of concrete-filled steel tubes, an aluminum alloy tube concrete structure is formed by combining an aluminum alloy tube and concrete. The aluminum alloy tube in this structure can exert a confinement effect on the concrete, making the concrete under triaxial compression, thereby improving the compressive strength and plastic properties of the concrete; at the same time, the concrete can delay or avoid the premature occurrence of local buckling of the aluminum alloy tube. In addition, the aluminum alloy tube also serves as a formwork for pouring its core concrete during the construction process, making the construction more convenient and easier to ensure the pouring quality of the concrete. This type of composite structure combines the advantages of concrete and aluminum alloy, and has characteristics such as high bearing capacity and corrosion resistance; compared with aluminum alloy structures, this type of composite structure delays the local buckling of the aluminum alloy tube to a certain extent and reduces the amount of aluminum alloy used. Therefore, the aluminum alloy tube concrete structure has broad application prospects in the field of civil engineering.

[0003] In order to further exert the advantages of the aluminum alloy tube concrete structure and reduce the amount of aluminum alloy used. Some patents and researches consider the combination of aluminum alloy tubes, concrete, steel tubes, etc., in order to give full play to the advantages of various materials. For example, CN219732514 U discloses an aluminum alloy tube ceramsite concrete composite column, which relates to the technical field of concrete composite columns, and includes a circular aluminum alloy tube and a circular steel tube. A circular steel tube is coaxially arranged inside the circular aluminum alloy tube. A plurality of connecting plates are connected along the radial direction between the inner surface of the circular aluminum alloy tube and the outer surface of the circular steel tube, and the plurality of connecting plates are evenly distributed around the axis of the circular steel tube. In this patent, the inner surface of the circular aluminum alloy tube is directly connected to the outer surface of the circular steel tube through longitudinal connecting plates. The longitudinal connecting plates, aluminum alloy tubes, and steel tubes use different metal materials. Due to the "potential difference" between dissimilar metals, after filling with concrete, the aluminum alloy tube is prone to electrochemical corrosion during service, thereby reducing the bearing capacity and service life of this type of structure.

[0004] CN 205776727 U discloses a combined component of a double-layer aluminum alloy pipe and sea sand reactive powder concrete. An annular cavity is formed between the inner aluminum alloy pipe and the outer aluminum alloy pipe of the patent, and a stiffening aluminum alloy plate for welding the inner aluminum alloy pipe and the outer aluminum alloy pipe into one body is arranged in the annular cavity. Due to the strong affinity of aluminum alloy with oxygen, it is extremely easy to combine with oxygen in the air to form insoluble and dense aluminum trioxide. The oxide film hinders the fusion and formation of the weld seam and is likely to cause defects such as slag inclusion and porosity in the deposited metal. In addition, the aluminum alloy has a high thermal conductivity and a large linear expansion coefficient, resulting in the easy formation of thermal cracks at the weld seam. For the above reasons, the strength of the aluminum alloy welding structure is reduced in the area near the weld seam. The strength of this area is generally 40% - 60% of the strength of the base metal, and the existence of this area will have a very adverse impact on the bearing capacity of the welding structure.

[0005] Therefore, to give full play to the advantages of high bearing capacity, corrosion resistance, and beautiful appearance of the aluminum alloy pipe concrete, and to solve or avoid the corrosion caused by the potential difference between the aluminum alloy and dissimilar metals (such as steel), as well as the problems brought about by the reduction of the strength in the welding heat affected zone, further reduce the aluminum alloy consumption and delay the buckling of the aluminum alloy pipe, and promote and expand the application of aluminum alloy in civil engineering, it is necessary to improve and optimize the structural design and preparation process of the aluminum alloy-concrete composite structure. Summary of the Invention

[0006] Aiming at the problems that the inner surface of the aluminum alloy pipe in the prior art is directly connected to the outer surface of the circular steel pipe through a longitudinal connecting plate, which is prone to electrochemical corrosion problems, and there are problems such as the reduction of the strength in the welding heat affected zone of the aluminum alloy, and combining the advantages of the aluminum alloy as a lightweight material to reduce the structural weight, the present invention provides an extruded double-layer aluminum alloy pipe lightweight concrete combined component and its preparation method, achieving the effects of corrosion resistance, high bearing capacity, convenient construction, beautiful appearance, and reduction of the structural self-weight.

[0007] The object of the present invention is achieved through the following technical solutions: An extruded double-layer aluminum alloy pipe lightweight concrete combined component, the pipe body is integrally formed by an extrusion molding process; The shape of the pipe body is as follows: the pipe body is composed of two concentric aluminum alloy pipes and multiple stiffening ribs, and multiple cavities are formed between the inner pipe, the outer pipe and the stiffening ribs; The pipe body is composed of three parts: an inner pipe, an outer pipe, and a stiffening rib. These three parts are integrally formed by an extrusion molding process, avoiding welding, and there is no gap in the whole pipe body; The thickness of the inner pipe wall > the thickness of the outer pipe wall, the thickness of the inner pipe wall ≤ the thickness of the stiffening rib ≤ the thickness of the outer pipe wall; the diameter ratio of the inner pipe to the outer pipe is 0.5 - 0.8; The material of the pipe body is selected from 6-series aluminum alloy or 7-series aluminum alloy. The nominal yield strength of the 6-series aluminum alloy is 200 MPa - 260 MPa, and the nominal yield strength of the 7-series aluminum alloy is 400 MPa - 500 MPa. The cavity of the pipe body is filled with lightweight concrete such as foam concrete, lightweight aggregate concrete, and aerogel concrete, and its density is 300 kg / m 3 ~1950 kg / m 3 ; The described extrusion-type double-layer aluminum alloy pipe lightweight concrete composite member has the following technical indicators: Using finite element software, for the range of material parameters of aluminum alloy and concrete commonly used in structural engineering, the mechanical properties of the double-layer aluminum alloy pipe lightweight concrete column were analyzed. The research results show that compared with the pure aluminum alloy structure, under the same aluminum alloy usage, the ultimate bearing capacity of the described extrusion-type double-layer aluminum alloy pipe lightweight concrete composite member is increased by 30% - 50%; when reaching the same ultimate bearing capacity, the aluminum alloy usage in this extrusion-type double-layer aluminum alloy pipe lightweight concrete composite member is reduced by 20% - 55%; and the aluminum alloy pipe of this composite member adopts a one-time hot extrusion forming process, avoiding the problem of reduced strength in the heat-affected zone caused by welding of aluminum alloy, and not using dissimilar metals also avoids electrochemical corrosion. The presence of the stiffening rib plate delays the outward local buckling of the outer pipe and improves the bearing capacity of the member; the pipe is filled with lightweight concrete such as foam concrete, lightweight aggregate concrete, and aerogel concrete. Compared with the aluminum alloy pipe concrete composite member using ordinary concrete of the same grade, the described extrusion-type double-layer aluminum alloy pipe lightweight concrete composite member reduces its self-weight by 20% - 40%.

[0008] Furthermore, the cross-sectional shape of the double-layer aluminum alloy pipe is circle-in-circle, circle-in-square, square-in-circle, square-in-circle, or polygon-in-polygon.

[0009] Furthermore, the number of the multiple stiffening ribs is 3 - 8.

[0010] Furthermore, the pipe body material is preferably 6A02, 6005A, 6060, 6061, 6063, 6082 in the 6-series aluminum alloy.

[0011] The present invention also relates to a preparation method of the above-mentioned extrusion-type double-layer aluminum alloy pipe lightweight concrete composite member, including the following steps: S1. Melting the aluminum alloy raw material; S2. Conducting ingot treatment on the melted aluminum alloy to form a billet; S3. Preheating the billet obtained in the previous step to 220 °C - 260 °C, then conducting surface lubrication treatment to form a 5 μm - 10 μm thick film on the surface, and loading the billet into the extrusion cylinder; S4. Select a die that matches the pipe specification and tightly connect it to the extrusion cylinder to obtain an aluminum alloy billet. S5. Extrusion molding: Heat the aluminum alloy billet obtained in the previous step to 490 °C - 520 °C and perform extrusion molding through an extruder at a speed of 10 m / min - 15 m / min to form a double-layer aluminum alloy pipe. S6. Air-cool the extruded double-layer aluminum alloy pipe for quenching. S7. Aging treatment: Heat the air-cooled and quenched aluminum alloy pipe to 170 °C - 180 °C and hold for 7 h - 9 h. S8. Reprocess the extruded product obtained in the previous step to remove burrs and straighten it. S9. Obtain the finished double-layer aluminum alloy pipe after passing the inspection. S10. Select lightweight concrete of different types and densities according to the design requirements, mix the lightweight concrete according to the design mix ratio, pour the prepared concrete into the cavity inside the aluminum alloy pipe, use a vibrating tool to vibrate the concrete densely, and perform post-maintenance treatment. After the concrete reaches the design strength, an extrusion-type double-layer aluminum alloy pipe lightweight concrete composite member is obtained. Compared with the pure aluminum alloy structure, under the same aluminum alloy consumption, the ultimate bearing capacity of the described extrusion-type double-layer aluminum alloy pipe lightweight concrete composite member is increased by 30% - 50%; when reaching the same ultimate bearing capacity, the aluminum alloy consumption in the described extrusion-type double-layer aluminum alloy pipe lightweight concrete composite member is reduced by 20% - 55%; compared with the aluminum alloy pipe concrete composite member using the same grade of ordinary concrete, the described extrusion-type double-layer aluminum alloy pipe lightweight concrete composite member reduces its self-weight by 20% - 40%.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. For the extrusion-type double-layer aluminum alloy pipe lightweight concrete composite member of the present invention, the inner and outer pipes and the stiffening ribs of the pipe body are all made of 6-series or 7-series aluminum alloy materials, which can avoid the electrochemical corrosion caused by the mixing of different metal materials. At the same time, the aluminum alloy has good corrosion resistance, which can reduce the cost of later maintenance, and the special metallic luster of the aluminum alloy makes the appearance beautiful without additional decoration.

[0013] 2. For the extrusion-type double-layer aluminum alloy pipe lightweight concrete composite member of the present invention, the pipe body is integrally formed by an extrusion molding process. The shape of the pipe body is as follows: the pipe body is composed of two concentric circular pipes and stiffening ribs, and multiple cavities are formed between the inner and outer pipes and the stiffening ribs. Among them, the inner and outer pipes and the stiffening ribs are integrally formed by an extrusion molding process, reducing the welding process.

[0014] 3. For the extrusion - type double - layer aluminum alloy tube lightweight concrete composite member of the present invention, the wall thickness of the inner tube is greater than that of the outer tube, and the thickness of the stiffening rib is between the wall thickness of the inner tube and the wall thickness of the outer tube (including the two values); the diameter ratio of the inner tube to the outer tube is 0.5 - 0.8; the main function of the outer tube is to improve the corrosion resistance of the overall member; when the outer tube cracks, the stiffening rib and the inner tube can improve the stability of the member, prevent or slow down the buckling of the outer aluminum alloy tube, and improve its load - bearing capacity.

[0015] 4. For the extrusion - type double - layer aluminum alloy tube lightweight concrete composite member of the present invention, the cavity inside the tube body is filled with lightweight concrete, which can greatly reduce the self - weight of the aluminum alloy - concrete member, and the concrete in the cavity can also play a role in heat insulation and fire protection for the inner tube, giving full play to the advantages of lightweight, high strength, and corrosion resistance of the aluminum alloy tube - concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, but do not constitute a limitation to the present invention.

[0017] Figure 1 It is a cross - sectional schematic diagram of the extrusion - type double - layer aluminum alloy tube lightweight concrete composite member prepared in Embodiment 1 of the present invention; Figure 2 It is a cross - sectional schematic diagram of the extrusion - type hollow - sandwich aluminum alloy tube lightweight concrete composite member prepared in Embodiment 2 of the present invention; Figure 3 Structural schematic diagram of the extrusion - type double - layer aluminum alloy tube lightweight concrete composite member described in Embodiment 1 of the present invention (Explanation of the drawings: 1. Aluminum alloy inner tube; 2. Aluminum alloy outer tube; 3. Stiffening rib; 4. Lightweight concrete; 5. Lightweight concrete); Figure 4 Structural schematic diagram of the extrusion - type hollow - sandwich aluminum alloy tube lightweight concrete composite member described in Embodiment 2 of the present invention (Explanation of the drawings: 1. Aluminum alloy inner tube; 2. Aluminum alloy outer tube; 3. Stiffening rib; 4. Lightweight concrete). DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] To make the purpose, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the specific embodiments and with reference to the drawings. It should be understood that these descriptions are merely exemplary and do not intend to limit the scope of the present invention. In addition, in the following description, the descriptions of well - known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0019] The present invention will be described in detail below in conjunction with the drawings and embodiments.

[0020] Embodiment 1: Extruded Double-Layer Aluminum Alloy Tube Lightweight Concrete Composite Component: As Figure 1 shown, a cross-sectional schematic diagram of an extruded double-layer aluminum alloy tube lightweight concrete composite component, and the extruded double-layer aluminum alloy tube lightweight concrete composite component is applied to the field of civil engineering; As Figure 3 shown, a structural schematic diagram of the extruded double-layer aluminum alloy tube lightweight concrete composite component described in Embodiment 1, which is composed of two parts: an aluminum alloy tube 1 and lightweight concrete 2. The aluminum alloy tube 1 is composed of an inner tube, an outer tube, and stiffening ribs. The material selected for the tube body is 6-series aluminum alloy, and the inner tube and outer tube cavities of the tube body are filled with lightweight concrete; The tube body is manufactured by an aluminum alloy extrusion forming process (hot extrusion) to be integrally formed. The connection of the three parts of the inner tube, outer tube, and stiffening ribs does not require welding and is integrally formed by the extrusion forming process, and there are no gaps in the whole tube body; The shape of the tube body is as follows: the tube body is composed of two concentric circular tubes and stiffening ribs. Multiple cavities are formed between the inner and outer tubes and the stiffening ribs. The wall thickness of the inner tube is greater than that of the outer tube, and the thickness of the stiffening rib plate is between the wall thickness of the inner tube and the wall thickness of the outer tube (including); the diameter ratio of the inner tube to the outer tube is 0.5.

[0021] The above-mentioned extruded double-layer aluminum alloy tube lightweight concrete composite component is manufactured as follows: S1. Melt the aluminum alloy raw materials; S2. Perform ingot casting on the melted aluminum alloy to form a billet; S3. Preheat the billet obtained in the previous step to 260 °C, then perform surface lubrication treatment to form a 5 μm - 10 μm thick film on the surface, and load the billet into the extrusion cylinder; S4. Select a mold matching the pipe specifications and tightly connect it with the extrusion cylinder to obtain an aluminum alloy billet; S5. Extrusion forming: heat the aluminum alloy billet obtained in the previous step to 520 °C and extrude it at a speed of 10 m / min through an extruder to form a double-layer aluminum alloy tube; S6. Air-cool the extruded double-layer aluminum alloy tube for quenching; S7. Aging treatment: heat the air-cooled quenched aluminum alloy tube to 180 °C and hold it for 7 h; S8. Re-process the extruded product obtained in the previous step to remove burrs and straighten it; S9. Obtain a finished double-layer aluminum alloy tube after passing the inspection; S10. Select lightweight concrete of different types and densities according to design requirements, mix the lightweight concrete according to the design mix ratio, pour the prepared concrete into the cavity inside the aluminum alloy pipe, use a vibrating tool to vibrate the concrete until it is dense, and perform post-curing treatment. After the concrete reaches the design strength, an extruded double-layer aluminum alloy pipe lightweight concrete composite member can be obtained; Compared with the pure aluminum alloy structure, under the same aluminum alloy consumption, the ultimate bearing capacity of the described extruded double-layer aluminum alloy pipe lightweight concrete composite member is increased by 30% - 50%; when reaching the same ultimate bearing capacity, the aluminum alloy consumption in the described extruded double-layer aluminum alloy pipe lightweight concrete composite member is reduced by 20% - 55%; compared with the concrete composite member of an aluminum alloy pipe using ordinary concrete of the same grade, the described extruded double-layer aluminum alloy pipe lightweight concrete composite member reduces its self-weight by 20% - 40%.

[0022] Example 2: Extruded hollow sandwich aluminum alloy pipe lightweight concrete composite member: As Figure 2 shown, the cross-sectional schematic diagram of the extruded hollow sandwich aluminum alloy pipe lightweight concrete composite member, and the described extruded hollow sandwich aluminum alloy pipe lightweight concrete composite member is applied in the field of civil engineering; As Figure 4 shown, the structural schematic diagram of the extruded hollow sandwich aluminum alloy pipe lightweight concrete composite member described in Example 2, which is composed of two parts: an aluminum alloy pipe 1 and lightweight concrete 2. The aluminum alloy pipe 1 is composed of an inner pipe, an outer pipe and stiffening ribs. The material selected for the pipe body is 7-series aluminum alloy; the sandwich cavities between the inner pipe and the outer pipe of the pipe body are filled with foam concrete, and the inner pipe is not filled with concrete; The pipe body is integrally formed by an extrusion molding process (hot extrusion). The connection of the three parts of the inner pipe, the outer pipe and the stiffening ribs does not require welding and is integrally formed by an extrusion molding process, and there are no gaps in the whole pipe body; The shape of the pipe body is as follows: the pipe body is composed of a rectangular outer pipe, a circular inner pipe and stiffening ribs, and multiple cavities are formed between the inner and outer pipes and the stiffening ribs. The wall thickness of the inner pipe is greater than the wall thickness of the outer pipe, and the thickness of the stiffening rib plate is between the wall thickness of the inner pipe and the wall thickness of the outer pipe (including);

[0023] The preparation method refers to Example 1; Compared with the pure aluminum alloy structure, under the same amount of aluminum alloy used, the ultimate bearing capacity of the extruded double-layer aluminum alloy tube lightweight concrete composite member is increased by 30% - 50%; when reaching the same ultimate bearing capacity, the amount of aluminum alloy used in the extruded double-layer aluminum alloy tube lightweight concrete composite member is reduced by 20% - 55%; compared with the ordinary concrete aluminum alloy tube concrete composite member with the same grade, the extruded double-layer aluminum alloy tube lightweight concrete composite member reduces its self-weight by 20% - 40%.

[0024] Comparative Example 1: CN 219732514 U discloses an aluminum alloy tube ceramsite concrete composite column, including a circular aluminum alloy tube and a circular steel tube. A circular steel tube is coaxially arranged inside the circular aluminum alloy tube. A plurality of connecting plates are radially connected between the inner surface of the circular aluminum alloy tube and the outer surface of the circular steel tube. However, the inner surface of the circular aluminum alloy tube and the outer surface of the circular steel tube are directly connected through longitudinal connecting plates, which is prone to electrochemical corrosion; moreover, the self-weight of the composite member of the double-layer aluminum alloy tube and the sea sand reactive powder concrete is relatively large, which does not match the advantage of aluminum alloy as a lightweight metal.

[0025] Compared with CN 219732514 U, the difference in the embodiment is that the inner and outer tubes and the stiffening rib connecting plates of the present extruded double-layer aluminum alloy tube lightweight concrete composite member are all made of aluminum alloy material, avoiding the problem of electrochemical corrosion caused by different materials and direct contact of each component, and the self-weight of the composite member of the double-layer aluminum alloy tube and the lightweight concrete is small.

[0026] Comparative Example 2: CN 205776727 U discloses a composite member of a double-layer aluminum alloy tube and sea sand reactive powder concrete. An annular cavity is formed between the inner aluminum alloy tube and the outer aluminum alloy tube of the patent, and a stiffening aluminum alloy plate for welding the inner aluminum alloy tube and the outer aluminum alloy tube into one body is arranged in the annular cavity. However, this patent does not solve the problem of the reduction of the strength of the heat affected zone caused by welding of aluminum alloy; moreover, the self-weight of the composite member of the double-layer aluminum alloy tube and the sea sand reactive powder concrete is relatively large, which does not match the advantage of aluminum alloy as a lightweight metal.

[0027] Compared with CN 205776727 U, the difference in the embodiment is that the present extruded double-layer aluminum alloy tube lightweight concrete composite member is fabricated by a hot extrusion one-step forming process, avoiding the problem of the reduction of the strength of the heat affected zone caused by welding of aluminum alloy, and the self-weight of the composite member of the double-layer aluminum alloy tube and the lightweight concrete is small.

[0028] Results and Discussions: 1. Through the comparison between the embodiment and Comparative Example 1, it shows that the present extruded double-layer aluminum alloy tube lightweight concrete composite member has good corrosion resistance, and the self-weight of the composite member of the double-layer aluminum alloy tube and the lightweight concrete is small.

[0029] 2. By comparing Example and Comparative Example 2, it is shown that the extrusion-type double-layer aluminum alloy pipe lightweight concrete composite member of the present invention avoids the problem of strength reduction in the heat-affected zone of aluminum alloy welding, and the composite member of the double-layer aluminum alloy pipe and lightweight concrete has a small self-weight.

[0030] It should be understood that the above specific embodiments of the present invention are only for illustrative explanation or interpretation of the principles of the present invention, and do not constitute a limitation to the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all variations and modifications that fall within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. An extruded double-layer aluminum alloy tube lightweight concrete composite component, characterized in that: The tube body is made by one-piece molding using an extrusion molding process; The shape of the tube body is as follows: the tube body is composed of two concentric aluminum alloy tubes and a plurality of stiffening ribs, and a plurality of cavities are formed between the inner tube, the outer tube and the stiffening ribs; The pipe body is composed of three parts: inner pipe, outer pipe and stiffening ribs. These three parts are made by extrusion molding process, which avoids welding and has no gaps in the whole pipe body. The thickness of the inner tube wall is greater than the thickness of the outer tube wall, the thickness of the inner tube wall is less than or equal to the thickness of the stiffening ribs and less than or equal to the thickness of the outer tube wall; the diameter ratio of the inner tube to the outer tube is 0.5 to 0.8; The material of the pipe body is selected from 6 series aluminum alloy or 7 series aluminum alloy, the nominal yield strength of 6 series aluminum alloy is 200 MPa ~ 260 MPa, and the nominal yield strength of 7 series aluminum alloy is 400 MPa ~ 500 MPa; the cavity of the pipe body is filled with foam concrete, lightweight aggregate concrete and aerogel concrete lightweight concrete, and its density is 300 kg / m 3 ~1950 kg / m 3 ; The extruded double-layer aluminum alloy tube lightweight concrete composite component has the following technical indicators: Compared with a pure aluminum alloy structure, under the same aluminum alloy dosage, the ultimate bearing capacity of the extruded double-layer aluminum alloy tube lightweight concrete composite component is increased by 30% to 50%; when the same ultimate bearing capacity is achieved, the aluminum alloy dosage in the extruded double-layer aluminum alloy tube lightweight concrete composite component is reduced by 20% to 55%; compared with an ordinary concrete aluminum alloy tube concrete composite component of the same grade, the extruded double-layer aluminum alloy tube lightweight concrete composite component reduces its own weight by 20% to 40%.

2. The extruded double-layer aluminum alloy tube lightweight concrete composite component according to claim 1 is characterized in that: The cross-sectional shape of the double-layer aluminum alloy tube is circle within circle, circle within square, square within circle, square within circle or polygon within polygon.

3. The extruded double-layer aluminum alloy tube lightweight concrete composite component according to claim 1, characterized in that: The number of the plurality of stiffening ribs is 3 to 8.

4. The extruded double-layer aluminum alloy tube lightweight concrete composite component according to claim 1, characterized in that: The tube body material is 6A02, 6005A, 6060, 6061, 6063, and 6082 among the 6 series aluminum alloys.

5. The method for preparing an extruded double-layer aluminum alloy tube lightweight concrete composite component according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1, melting the aluminum alloy raw material; S2, casting the molten aluminum alloy into an ingot to form a billet; S3, preheating the rod blank obtained in the above step to 220°C to 260°C, and then performing surface lubrication treatment to form a 5 μm to 10 μm thick film on the surface, and loading the rod blank into an extrusion cylinder; S4, select a die that matches the specifications of the pipe and tightly connect it to the extrusion cylinder to obtain an aluminum alloy billet; S5, extrusion molding: heating the aluminum alloy billet obtained in the above step to 490° C. to 520° C., and extruding it through an extruder at a speed of 10 m / min to 15 m / min to form a double-layer aluminum alloy tube; S6, air-cooling and quenching the extruded double-layer aluminum alloy tube; S7, aging treatment: heat the aluminum alloy tube after air cooling and quenching to 170 ℃ ~ 180 ℃ and keep it for 7 h ~ 9 h; S8, reprocessing the extruded product after the above step, removing burrs and correcting; S9. After passing the inspection, the finished double-layer aluminum alloy tube is obtained; S10. Select lightweight concrete of different types and densities according to design requirements, mix the lightweight concrete according to the designed mix ratio, pour the prepared concrete into the cavity inside the aluminum alloy tube, and use a vibrating tool to compact the concrete, and perform subsequent maintenance treatment. When the concrete reaches the designed strength, an extruded double-layer aluminum alloy tube lightweight concrete composite component is obtained; Compared with a pure aluminum alloy structure, under the same aluminum alloy dosage, the ultimate bearing capacity of the extruded double-layer aluminum alloy tube lightweight concrete composite component is increased by 30% to 50%; when the same ultimate bearing capacity is achieved, the aluminum alloy dosage in the extruded double-layer aluminum alloy tube lightweight concrete composite component is reduced by 20% to 55%; compared with an ordinary concrete aluminum alloy tube concrete composite component of the same grade, the extruded double-layer aluminum alloy tube lightweight concrete composite component reduces its own weight by 20% to 40%.

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