A new type of high-strength recombined bamboo composite truss

Abstract

The utility model discloses a novel high -strength reorganization bamboo composite truss relates to reorganization bamboo composite truss technical field, including upper chord, lower chord, straight web and inclined web, upper chord, lower chord, straight web and inclined web all adopt reorganization bamboo composite pole piece, reorganization bamboo composite pole piece includes reorganization bamboo base material layer and fiber reinforced layer, and fiber reinforced layer is the laminated board that carbon fiber, glass fiber or aramid fiber is compounded with resin, and is equipped with the reinforcing connection structure at the composite truss connecting joint, the reinforcing connection structure includes the reorganization bamboo clamp plate inlayed in reorganization bamboo composite pole piece inside, through the fiber reinforced layer set up, has improved reorganization bamboo composite pole piece whole's tensile and compressive strength, under the effect of fiber reinforced composite clamp plate, elastic gasket, reorganization bamboo clamp plate and U type reinforcing strip, has improved the shear strength at the connecting joint, and through the elastic gasket set up, avoids the stress concentration that metal and bamboo material expansion coefficient difference leads to.

Description

Technical Field

[0001] This utility model relates to the field of reconstituted bamboo composite truss technology, specifically a novel high-strength reconstituted bamboo composite truss. Background Technology

[0002] Truss structures are favored because their members primarily bear tension or compression, maximizing material performance and thus saving material and reducing overall structural weight. Common truss types include steel trusses, reinforced concrete trusses, prestressed concrete trusses, timber trusses, steel-timber composite trusses, and steel-concrete composite trusses. Since truss members primarily bear axial tension or compression, the strength of the material can be fully utilized. Especially in large-span applications, trusses save more material, reduce self-weight, and increase structural stiffness compared to solid-web beams. Reconstituted bamboo is an environmentally friendly material made by processing bamboo into bundles of fibers or shreds, drying, gluing, and hot-pressing. It boasts advantages such as high strength, good weather resistance, and low cost.

[0003] Chinese Patent Publication No. CN213014987U discloses a bamboo truss, comprising a first bamboo and a second bamboo. The first bamboo has several first connecting members fitted onto it, and the second bamboo has several second connecting members fitted onto it. The first and second connecting members are staggered in sequence. Adjacent first and second connecting members are connected by a third bamboo and a cable. One end of the third bamboo is inserted into a first connecting member, and the other end is inserted into a second connecting member. One end of the cable passes through the first bamboo and the first connecting member and is fixed to the first connecting member. The other end of the cable passes through the third bamboo, the first bamboo, and the second connecting member and is fixed to the second connecting member. This truss is easy to assemble on-site, has a relatively strong connection, and offers high safety in use.

[0004] Chinese Patent Publication No. CN203878743U discloses a truss comprising N first connecting rods, N second connecting rods, two horizontal bars made of bamboo, N+1 diagonal bars, several fixing plates, and N padding rods; the truss structure of this utility model is simple, lightweight, durable, and has high rigidity.

[0005] However, the inventor of the aforementioned device believes it has certain shortcomings:

[0006] 1. Insufficient connection strength at connection nodes: Connection nodes using bolts are prone to failure due to the low shear strength of bamboo along the grain;

[0007] 2. Corrosion resistance depends on surface treatment: the cemented interface may fail after long-term exposure to the environment;

[0008] 3. Limitations of metal reinforcement: The difference in expansion coefficients between metal and bamboo leads to stress concentration and reduces durability. Therefore, this utility model provides a new type of high-strength reconstituted bamboo composite truss. Utility Model Content

[0009] The purpose of this invention is to provide a novel high-strength reconstituted bamboo composite truss to solve the problems raised in the prior art.

[0010] To achieve the above objectives, this utility model provides the following technical solution: a novel high-strength reconstituted bamboo composite truss, comprising an upper chord, a lower chord, straight web members, and diagonal web members. All the upper chord, lower chord, straight web members, and diagonal web members are made of reconstituted bamboo composite members. Each reconstituted bamboo composite member includes a reconstituted bamboo substrate layer and a fiber reinforcement layer. The fiber reinforcement layer is a laminate composed of carbon fiber, glass fiber, or aramid fiber and resin. Reinforcing connection structures are provided at the connection nodes of the composite truss. These reinforcing connection structures include reconstituted bamboo plywood embedded inside the reconstituted bamboo composite member and fiber-reinforced composite plywood installed on both sides of the reconstituted bamboo composite member. Elastic gaskets are provided between the fiber-reinforced composite plywood and the contact surface of the reconstituted bamboo composite member. U-shaped reinforcing strips are embedded on both sides of the reconstituted bamboo composite member.

[0011] Preferably, the fiber reinforcement layers of the upper chord and lower chord are respectively disposed on the tension side and the compression side, and the fiber reinforcement layers of the straight web members and the diagonal web members are symmetrically disposed on both sides.

[0012] Preferably, the elastic gasket is a nitrile rubber or epoxy resin-based elastomer with a thickness of 1-3 mm.

[0013] Preferably, the fiber-reinforced composite plywood, elastic gasket, reconstituted bamboo composite rod and reconstituted bamboo plywood are connected by high-strength bolts, and the reinforced connection structure is installed on the reconstituted bamboo composite rod by high-strength bolts.

[0014] Preferably, the fiber direction of the fiber reinforcement layer is consistent with the force direction of the reconstituted bamboo composite rod, the thickness of the fiber reinforcement layer in the upper chord and lower chord is 3-5mm, and the thickness of the fiber reinforcement layer in the straight web and diagonal web is 2-4mm.

[0015] Preferably, the reconstituted bamboo composite rod has grooves on both sides, and the U-shaped reinforcing strip is embedded in the grooves. The grooves facilitate the installation and fixing of the U-shaped reinforcing strip.

[0016] Preferably, the outer surface of the fiber-reinforced composite plywood is coated with an epoxy resin coating with a thickness of ≥0.5mm. By coating the outer surface of the fiber-reinforced composite plywood with an epoxy resin coating, its weather resistance is improved.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] 1. This application improves the overall tensile and compressive strength of the reconstituted bamboo composite rod by setting a fiber reinforcement layer. Under the action of fiber reinforced composite plywood, elastic gasket, reconstituted bamboo plywood and U-shaped reinforcing strip, the shear strength at the connection node is improved. And the elastic gasket avoids stress concentration caused by the difference in expansion coefficient between metal and bamboo.

[0019] 2. This application reduces the erosion of the bonding interface by setting a fiber reinforcement layer, and the surface of the fiber reinforced composite plywood is treated with anti-corrosion to extend its service life.

[0020] 3. This application uses bamboo instead of wood or steel as the main material for the truss, which has a density of only one-quarter that of steel structures, making construction convenient and cost-effective. Attached Figure Description

[0021] Figure 1 This is a structural schematic diagram of a novel high-strength reconstituted bamboo composite truss according to the present invention;

[0022] Figure 2 This is a schematic diagram of the enhanced connection structure of a novel high-strength reconstituted bamboo composite truss according to the present invention;

[0023] Figure 3 This is a schematic diagram of the reconstituted bamboo composite member structure of a novel high-strength reconstituted bamboo composite truss according to this utility model.

[0024] Labels in the diagram: 1. Top chord; 2. Bottom chord; 3. Straight web member; 4. Diagonal web member; 5. Fiber-reinforced composite plywood; 6. Elastic gasket; 7. Reconstituted bamboo plywood; 8. High-strength bolt; 9. U-shaped reinforcing strip; 10. Reconstituted bamboo composite rod; 11. Reconstituted bamboo substrate layer; 12. Fiber-reinforced layer. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] Please see Figure 1 , Figure 2 and Figure 3A novel high-strength reconstituted bamboo composite truss includes an upper chord 1, a lower chord 2, straight web members 3, and diagonal web members 4. All four members (10, 11, 12, 13, and 14) are constructed from reconstituted bamboo composite members. Each reconstituted bamboo composite member 10 includes a reconstituted bamboo substrate layer 11 and a fiber reinforcement layer 12. The fiber reinforcement layers 12 of the upper chord 1 and lower chord 2 are respectively located on the tension and compression sides. The fiber reinforcement layers 12 of the straight web members 3 and diagonal web members 4 are symmetrically located on their two sides. The thickness of the reconstituted bamboo substrate layer 11 is... The composite bamboo pole 10, accounting for 60%-80%, is dried to a moisture content of 8%-12%. The fiber reinforcement layer 12 accounts for 20%-40% of the thickness. The fiber reinforcement layer 12 is a laminate made of carbon fiber, glass fiber or aramid fiber and resin. It is bonded to the composite bamboo substrate layer 11 through a hot pressing process. The truss adopts a variable cross-section design. The thickness of the chord and web members in the mid-span is increased by 10%-20%. Hollow cavities are set inside the chord members, with built-in lightweight reinforcing ribs such as bamboo fiber rods.

[0027] Please refer to it again. Figure 1 , Figure 2 and Figure 3 The fiber direction of the fiber reinforcement layer 12 is consistent with the force direction of the reconstituted bamboo composite rod 10. The thickness of the fiber reinforcement layer 12 in the upper chord rod 1 and the lower chord rod 2 is 3-5mm, and the thickness of the fiber reinforcement layer 12 in the straight web rod 3 and the oblique web rod 4 is 2-4mm.

[0028] Please refer to it again. Figure 1 and Figure 2 The composite truss connection nodes are equipped with a reinforced connection structure, which includes a reconstituted bamboo plywood 7 embedded inside the reconstituted bamboo composite member 10 and fiber-reinforced composite plywood 5 installed on both sides of the reconstituted bamboo composite member 10. The outer surface of the fiber-reinforced composite plywood 5 is coated with an epoxy resin coating with a thickness of ≥0.5mm. The two fiber-reinforced composite plywood 5 and the reconstituted bamboo plywood 7 form a "sandwich" type plywood connection, and the surface of the fiber-reinforced composite plywood 5 is treated with anti-corrosion to extend its service life.

[0029] Please refer to it again. Figure 1 and Figure 2 An elastic gasket 6 is provided between the contact surfaces of the fiber-reinforced composite plywood 5 and the reconstituted bamboo composite rod 10. The elastic gasket 6 is made of nitrile rubber or epoxy resin-based elastomer with a thickness of 1-3mm. Under the action of the elastic gasket 6, stress concentration caused by the difference in expansion coefficients between metal and bamboo is avoided. The fiber-reinforced composite plywood 5, the elastic gasket 6, the reconstituted bamboo composite rod 10 and the reconstituted bamboo plywood 7 are connected by high-strength bolts 8. The elastic gasket 6 and the reinforcing connection structure are installed on the reconstituted bamboo composite rod 10 by the high-strength bolts 8.

[0030] Please refer to it again. Figure 1 and Figure 2Both sides of the reconstituted bamboo composite pole 10 are inlaid with U-shaped reinforcing strips 9. Both sides of the reconstituted bamboo composite pole 10 are provided with grooves, and the U-shaped reinforcing strips 9 are inlaid inside the grooves. The grooves are pre-processed on the surface of the reconstituted bamboo composite pole 10 in the node area. After the U-shaped reinforcing strips 9 of the same material as the fiber reinforcement layer 12 are embedded, adhesive is applied. The embedding depth is one-third of the pole cross-sectional thickness.

[0031] Working principle: The reconstituted bamboo substrate layer 11 is dried to a moisture content of 8%-12% and bonded to the fiber reinforcement layer 12 via a hot-pressing process, with the fiber direction aligned with the stress direction. Grooves are created on the reconstituted bamboo composite rod 10 to accommodate the reconstituted bamboo plywood 7 and U-shaped reinforcing strips 9. After embedding the U-shaped reinforcing strips 9 and reconstituted bamboo plywood 7, adhesive is applied. An elastic gasket 6 is placed between the fiber-reinforced composite plywood 5 and the treated reconstituted bamboo composite rod 10. The rod is then connected and fixed using high-strength bolts 8. The cross-section of the reconstituted bamboo composite rod 10 is thickened using a molding process at its mid-span, and bamboo fiber rods are embedded within. To strengthen the ribs and improve local stiffness, an epoxy resin coating is sprayed onto the outer surface of the fiber-reinforced composite plywood 5 to enhance its weather resistance. The fiber reinforcement layer 12 improves the overall tensile and compressive strength of the reconstituted bamboo composite pole 10. The fiber-reinforced composite plywood 5, elastic gasket 6, reconstituted bamboo plywood 7, and U-shaped reinforcing strip 9 enhance the shear strength at the connection nodes. The elasticity of the elastic gasket 6 prevents stress concentration caused by the difference in expansion coefficients between metal and bamboo. The service life is extended by applying an epoxy coating to the surface of the fiber-reinforced composite plywood 5 for corrosion protection.

[0032] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A novel high-strength reconstituted bamboo composite truss, comprising an upper chord (1), a lower chord (2), straight web members (3), and diagonal web members (4), characterized in that: The upper chord (1), lower chord (2), straight web member (3) and oblique web member (4) are all made of reconstituted bamboo composite members (10), which include a reconstituted bamboo substrate layer (11) and a fiber reinforcement layer (12). The composite truss connection node is provided with a reinforcing connection structure, which includes a reconstituted bamboo plywood (7) embedded inside the reconstituted bamboo composite rod (10) and fiber reinforced composite plywood (5) installed on both sides of the reconstituted bamboo composite rod (10). An elastic gasket (6) is provided between the fiber reinforced composite plywood (5) and the contact surface of the reconstituted bamboo composite rod (10). Both sides of the reconstituted bamboo composite rod (10) are inlaid with U-shaped reinforcing strips (9).

2. The novel high-strength reconstituted bamboo composite truss according to claim 1, characterized in that: The fiber reinforcement layers (12) of the upper chord (1) and lower chord (2) are respectively provided on the tension side and the compression side, and the fiber reinforcement layers (12) of the straight web member (3) and the oblique web member (4) are symmetrically provided on both sides.

3. The novel high-strength reconstituted bamboo composite truss according to claim 1, characterized in that: The elastic pad (6) is a nitrile rubber or epoxy resin-based elastomer with a thickness of 1-3 mm.

4. The novel high-strength reconstituted bamboo composite truss according to claim 1, characterized in that: The fiber-reinforced composite plywood (5), elastic gasket (6), reconstituted bamboo composite rod (10) and reconstituted bamboo plywood (7) are connected by high-strength bolts (8).

5. A novel high-strength reconstituted bamboo composite truss according to claim 1, characterized in that: The fiber direction of the fiber reinforcement layer (12) is consistent with the force direction of the reconstituted bamboo composite rod (10). The thickness of the fiber reinforcement layer (12) in the upper chord (1) and lower chord (2) is 3-5 mm, and the thickness of the fiber reinforcement layer (12) in the straight web rod (3) and oblique web rod (4) is 2-4 mm.

6. A novel high-strength reconstituted bamboo composite truss according to claim 1, characterized in that: The reconstituted bamboo composite rod (10) has grooves on both sides, and the U-shaped reinforcing strip (9) is embedded in the groove.

7. A novel high-strength reconstituted bamboo composite truss according to claim 1, characterized in that: The outer surface of the fiber-reinforced composite plywood (5) is coated with an epoxy resin coating with a thickness ≥0.5mm.

Images