A prefabricated T-beam and a manufacturing method thereof

Abstract

The invention discloses a prefabricated T-beam, the web plate includes: FRP prefabricated formwork, engineering bamboo, transverse shear screw; the FRP prefabricated formwork is groove-shaped, serving as the web plate shell, the groove extends into the flange plate to be turned inside and outside the flange plate; the engineering bamboo is a cuboid, the main body of the engineering bamboo is arranged in the FRP prefabricated formwork, and a part of the engineering bamboo extends into the flange plate; there are several transverse shear screws, which are distributed on the engineering bamboo in an array, pass through the engineering bamboo along the width direction of the engineering bamboo, and the length is the same as the inner width of the FRP prefabricated formwork; fine aggregate cement-based grouting material is poured in the gap between the FRP prefabricated formwork and the engineering bamboo; the flange plate also includes: loop belt reinforcement and angle steel bar; the angle steel bar is arranged between the bending angle of the FRP prefabricated formwork and the stirrup in the flange plate; the loop belt reinforcement connects the angle steel bar and the longitudinal steel bar in the flange plate; the stirrup in the flange plate passes through the FRP prefabricated formwork and the engineering bamboo. The invention gives full play to the mechanical properties of three materials and can prevent the engineering bamboo from suffering from brittle failure.

Description

Technical Field

[0001] The invention relates to the technical field of prefabricated components, and in particular to a prefabricated T-beam and a manufacturing method thereof. Background Art

[0002] With the deepening of my country's carbon peak and carbon neutrality strategies, energy conservation and emission reduction in the construction field has become a key link in achieving the dual carbon goals. Engineered bamboo uses low-carbon, carbon-fixing, renewable and degradable round bamboo as raw material, and is prepared through cutting, steaming, carbonization, drying, gluing, reorganization and other processes. It has the advantages of light weight, high strength, stable performance, and green environmental protection. It is a new type of building material with great development potential. Using engineering bamboo to replace some conventional building materials can effectively reduce carbon emissions in the production process of building materials, and provide an effective way to achieve low-carbon, environmental protection and sustainable development in the construction industry. However, the compressive and shear resistance of engineering bamboo is weak, it is prone to brittle failure, and its durability is insufficient, which limits the application and promotion of engineering bamboo in construction projects. It is urgent to establish a new type of engineering bamboo building structure system to solve the problems of bearing capacity and durability involved in the project.

[0003] In order to improve the performance defects of engineered bamboo, the method of combining engineered bamboo with other building materials to form a composite structure is currently adopted in engineering applications to achieve coordinated force and performance improvement of the structure and make up for the shortcomings of each material.

[0004] There are four types of existing engineered bamboo composite structures: engineered bamboo-steel composite structure, engineered bamboo-aluminum plate composite structure, engineered bamboo-FRP composite structure and engineered bamboo-concrete composite structure.

[0005] (1) The engineered bamboo-steel composite structure is a composite structure of engineered bamboo and cold-bent thin-walled steel sections of corrugated steel sheets, C-shaped steel, U-shaped steel, etc., which are bonded together by structural adhesives or structural adhesives plus self-tapping screws. This composite structure can give full play to the advantages of both engineered bamboo and steel sections, and can also improve the integrity, bearing capacity and material utilization of the structure. However, when the steel section enters the yield stage, the deformation of the engineered bamboo and the steel section is not coordinated, and peeling damage is easily caused between the engineered bamboo and the steel section.

[0006] (2) Engineered bamboo-aluminum plate composite structure (CN215978055U) is formed by connecting engineered bamboo and aluminum plates in the tensile zone by gluing and screwing. It has the advantages of short construction period and good tensile and bending resistance, but it is prone to interlayer shear slip when bearing load;

[0007] (3) Engineered bamboo-FRP composite structure (patent CN 113389128 A) considers the interface slip effect between FRP and engineered bamboo, uses bolts, structural adhesives and rivets to connect the two material components to form an I-beam or box beam composite structure. However, there are FRP and engineered bamboo in both the compression zone and the tension zone, which cannot fully exert the good tensile strength of FRP and the bending strength of engineered bamboo, and cannot avoid the shear failure of engineered bamboo;

[0008] (4) Engineered bamboo-concrete composite structure (patent CN 108316556 A) connects the engineered bamboo box beam and the concrete flange plate through shear keys to form a composite T beam, and achieves joint force of several materials by bonding FRP materials at the bottom. However, the connection method of each component is single, which is prone to slippage or interface damage, resulting in the bearing capacity of the composite structure failing to meet the design requirements. Summary of the invention

[0009] The invention provides a prefabricated T-beam and a manufacturing method thereof, so as to solve the problems in the prior art that the engineering bamboo beams are insufficient in compression and shear resistance and durability, and that the materials of the composite beams are subjected to coordinated forces.

[0010] The invention provides a prefabricated T-beam, comprising: a flange plate and a web plate; the web plate comprises: an FRP prefabricated formwork, an engineering bamboo, and a transverse shear screw; the FRP prefabricated formwork is in a groove shape and serves as a web plate outer shell; the notch of the FRP prefabricated formwork extends into the flange plate, and the notch is turned inside and outside the flange plate and bent; the engineering bamboo is in a rectangular parallelepiped, the main body of the engineering bamboo is arranged in the FRP prefabricated formwork, a part of the engineering bamboo extends into the flange plate, the length of the engineering bamboo is the same as the length of the FRP prefabricated formwork, and the width of the engineering bamboo is less than the inner width of the FRP prefabricated formwork; there are a number of transverse shear screws, which are distributed on the engineering bamboo in an array, the transverse shear screws pass through the engineering bamboo along the width direction of the engineering bamboo, and the length of the transverse shear screws is the same as the inner width of the FRP prefabricated formwork; fine aggregate cement-based grouting material is poured into the gap between the FRP prefabricated formwork and the engineering bamboo;

[0011] The flange plate also includes: loop strip reinforcement and angle steel bars; the angle steel bars are arranged between the bending angle of the FRP prefabricated formwork and the stirrups in the flange plate; the loop strip reinforcement connects the angle steel bars and the longitudinal steel bars in the flange plate; one long side of the stirrups in the flange plate passes through the FRP prefabricated formwork and the engineering bamboo in the flange plate.

[0012] Furthermore, the notch of the FRP prefabricated shell is bent outward at 1 / 2 of the height inside the flange plate.

[0013] Furthermore, the height of the engineered bamboo extending into the flange board is 2 / 3 of the height of the flange board.

[0014] Furthermore, the material of the engineered bamboo is bamboo laminated timber, reconstructed bamboo or bamboo-wood composite material.

[0015] The present invention also provides a method for manufacturing a prefabricated T-beam, comprising the following steps:

[0016] Step 1: Impregnate the FRP sheets with resin, stack the thickness, and splice them into a groove-shaped FRP prefabricated shell after curing and forming, and turn the groove of the FRP prefabricated shell outward and fold the edge;

[0017] Step 2: Insert several transverse shear screws into the engineered bamboo in an array along the width direction of the engineered bamboo;

[0018] Step 3: Lift the engineered bamboo and place it in the FRP prefabricated formwork. The engineered bamboo does not contact the bottom surface of the FRP prefabricated formwork, and both ends of the transverse shear screw are against the inner wall of the FRP prefabricated formwork.

[0019] Step 4: Tie the stirrups in the flange plate, arrange the longitudinal steel bars and tie the stirrups. When tying the stirrups, one long side of the stirrups passes through the FRP prefabricated formwork and engineered bamboo extending into the flange plate;

[0020] Step 5: Install the angle steel bar between the bending angle of the FRP precast formwork and the stirrups in the flange plate, pass the loop bar through the FRP precast formwork, surround the angle steel bar, tie it with the longitudinal steel bar, and pull up the angle steel bar;

[0021] Step 6: Set up the flange plate formwork, pour fine aggregate cement-based grouting material between the FRP prefabricated formwork and the engineered bamboo until the top of the web, and then pour coarse aggregate cement-based grouting material in the flange plate formwork. After the cement-based grouting material solidifies, the manufacturing process is completed.

[0022] Furthermore, when one long side of the stirrup passes through the FRP prefabricated formwork and the engineered bamboo extending into the flange plate, it is ensured that the bending position of the FRP prefabricated formwork extending into the flange plate is at 1 / 2 height inside the flange plate, and the engineered bamboo extends into 2 / 3 height of the flange plate.

[0023] Beneficial effects of the present invention:

[0024] The present invention gives full play to the mechanical properties of three materials. The engineered bamboo, cement-based grouting material and FRP formwork at the web are subjected to tensile stress at the same time, and the engineered bamboo and cement-based grouting material at the flange are subjected to compressive stress at the same time, giving full play to the bending resistance of the engineered bamboo, reducing the pressure on the engineered bamboo, and avoiding brittle damage to the engineered bamboo. It has the advantages of prefabrication and assembly, simple operation, joint stress of various components, wide application range, green environmental protection, and sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0026] Figure 1 It is a front view of a T-beam in a specific embodiment of the present invention;

[0027] Figure 2 It is a schematic diagram of the connection between the flange plate and the web plate in a specific embodiment of the present invention;

[0028] Figure 3 It is a schematic diagram of the loop band reinforcement and the angle steel bar after bundling in a specific embodiment of the present invention;

[0029] Figure 4 A schematic diagram of stirrups in a specific embodiment of the present invention;

[0030] Figure 5 This is a schematic diagram of the structure after the installation of engineered bamboo, FRP prefabricated formwork and stirrups;

[0031] Figure 6 Schematic diagram of the structure after installing FRP angle steel bars and loop reinforcement and before pouring cement-based grouting material. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0033] The embodiment of the present invention provides a prefabricated T-beam, such as Figure 1 , 2 4, including: flange plate, web plate; the flange plate body adopts the existing flange plate structure, mainly composed of stirrups 5, longitudinal steel bars 9 and coarse aggregate cement-based grouting material 2, but also improved on the basis of the existing structure. The present invention redesigns the web plate structure,

[0034] The web includes: an FRP prefabricated formwork 3, an engineered bamboo 1, and a transverse shear screw 4; the FRP prefabricated formwork 3 is groove-shaped and, as a web shell, can replace the formwork for making beams and also realize structural acceptance; the notch of the FRP prefabricated formwork 3 extends into the flange plate, and the notch is turned outward at 1 / 2 of the height inside the flange plate; the engineered bamboo 1 is a cuboid, and the material of the engineered bamboo 1 is bamboo integrated material or reconstructed bamboo or bamboo-wood composite material, which is the main bearing structure of the beam under bending. The main body of the engineered bamboo 1 is arranged in the FRP prefabricated formwork 3, and the height of the top extending into the flange plate is 2 / 3 of the height of the flange plate, which makes full use of the good bending resistance of the engineered bamboo 1, reduces the pressure on the engineered bamboo 1, and avoids the brittle failure of the engineered bamboo 1. The length of the engineered bamboo 1 is the same as that of the FRP prefabricated formwork The lengths of the shells 3 are the same, and the width of the engineered bamboo 1 is smaller than the inner width of the FRP prefabricated formwork 3; there are several transverse shear screws 4, which are distributed in an array on the engineered bamboo 1, and the transverse shear screws 4 pass through the engineered bamboo 1 along the width direction of the engineered bamboo 1, and the length of the transverse shear screws 4 is the same as the inner width of the FRP prefabricated formwork 3; fine aggregate cement-based grouting material is poured into the gap between the FRP prefabricated formwork 3 and the engineered bamboo 1; the transverse shear screws 4 pass through the engineered bamboo 1, and both ends extend out to be poured with the cement-based grouting material, so that the engineered bamboo 1 and the cement-based grouting material can jointly bear the tensile stress, and give full play to the lightweight and anti-bending ability of the engineered bamboo 1. The number of transverse shear screws 4 can be appropriately increased or decreased according to needs, and a row of transverse shear screws 4 needs to be added at intervals along the longitudinal direction of the beam.

[0035] like Figure 2 , 3 As shown, the flange plate also includes: loop belt reinforcement 6 and angle steel bar 7; the angle steel bar 7 is arranged between the bending angle of the FRP prefabricated formwork 3 and the stirrup 5 in the flange plate, and the angle steel bar 7 can constrain the bending angle of the FRP prefabricated formwork 3 to prevent the FRP prefabricated formwork 3 from sliding down, provide pre-tensioning force for the FRP prefabricated formwork 3, and give full play to the tensile performance of FRP; the loop belt reinforcement 6 passes through the FRP prefabricated formwork 3 and bends the two ends to pull up the angle steel bar 7, and uses its tension and the bending angle to pull the angle steel bar 7. The angle steel bar 7 is fixed at the position to prevent the angle steel bar 7 from sliding off and transmitting the tensile force; the bending part of the FRP prefabricated formwork 3 is used to restrict the displacement and cracking of the web engineering bamboo 1, and is connected with the angle steel bar 7, the loop belt bar 6 and the cement-based grouting material in the flange plate to bear the force synergistically; one long side of the stirrup 5 in the flange plate passes through the FRP prefabricated formwork 3 and the engineering bamboo 1 in the flange plate, so as to support and restrict the movement of the FRP prefabricated formwork 3 and the engineering bamboo 1.

[0036] The prefabrication process of T beam is as follows:

[0037] Step 1: Impregnate the FRP sheets with resin and stack them to a certain thickness, and wait for them to solidify and form, which is the FRP prefabricated formwork 3. Holes are set at the cross-section of the steel bars, and the FRP prefabricated formwork 3 is hoisted in place and placed on the bracket to replace the formwork;

[0038] Step 2: Set the steel bar transverse through holes on the engineered bamboo 1 beam, which must coincide with the steel bar transverse through holes of the FRP prefabricated formwork 3. Set transverse shear screws 4 at a certain interval on the side of the engineered bamboo 1. When the engineered bamboo 1 is in the center position, tighten the nuts, lift the engineered bamboo 1, and place it in the FRP prefabricated formwork 3. The two ends of the screws are against the FRP prefabricated formwork 3 to prevent the movement, dislocation and eccentricity of the engineered bamboo 1.

[0039] Step 3: The stirrups 5 at the flange are disconnected away from the tying angle, and the long side stirrups 5 at the lower part pass through the FRP prefabricated formwork 3, the engineered bamboo 1, and the FRP prefabricated formwork 3 in sequence, and the stirrups 5 on both sides are overlapped and tied according to the standard length, and the longitudinal steel bars 9 are arranged and tied together with the stirrups 5, such as Figure 5 As shown;

[0040] Step 4: Install the FRP angle steel bar 7 to the corner of the FRP prefabricated formwork 3, pass the loop steel bar 6 through the FRP prefabricated formwork 3, surround the FRP angle steel bar 7, and pull up the FRP angle steel bar 7. The openings at both ends of the loop steel bar 6 are not closed, and the loop steel bar 6 is tied to the longitudinal reinforcement to transfer the force, such as Figure 6 As shown;

[0041] Step 5: Support the precast beam support and the formwork at the flange, pour cement-based grouting material containing fine aggregate to the top of the web, and wait for solidification to complete;

[0042] Step 6: After the initial setting of the fine aggregate cement-based grouting material at the web is completed, pour the cement-based grouting material containing coarse aggregate on the flange and wait for the solidification to be completed. At this point, the prefabrication of the engineering bamboo 1 · grouting material · FRP formwork composite T-beam is completed.

[0043] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A prefabricated T-beam, comprising: Flange plate, web plate, the flange plate includes: stirrups, longitudinal steel bars; the web plate is characterized in that: the web plate includes: FRP prefabricated formwork, engineered bamboo, transverse shear screw; the FRP prefabricated formwork is groove-shaped, serving as the web plate outer shell; the notch of the FRP prefabricated formwork extends into the flange plate, and the notch is turned inside and outside the flange plate; the engineered bamboo is a cuboid, the main body of the engineered bamboo is arranged in the FRP prefabricated formwork, a part of the engineered bamboo extends into the flange plate, the length of the engineered bamboo is the same as the length of the FRP prefabricated formwork, and the width of the engineered bamboo is less than the inner width of the FRP prefabricated formwork; there are several transverse shear screws, which are distributed in an array on the engineered bamboo, and the transverse shear screws pass through the engineered bamboo along the width direction of the engineered bamboo, and the length of the transverse shear screws is the same as the inner width of the FRP prefabricated formwork; the gap between the FRP prefabricated formwork and the engineered bamboo is poured with fine aggregate cement-based grouting material; The flange plate also includes: loop strip reinforcement and angle steel bars; the angle steel bars are arranged between the bending angle of the FRP prefabricated formwork and the stirrups in the flange plate; the loop strip reinforcement connects the angle steel bars and the longitudinal steel bars in the flange plate; one long side of the stirrups in the flange plate passes through the FRP prefabricated formwork and the engineering bamboo in the flange plate.

2. The prefabricated T-beam according to claim 1, characterized in that: The notch of the FRP prefabricated formwork is turned outward at 1 / 2 of the height inside the flange plate.

3. The prefabricated T-beam according to claim 1, characterized in that: The height of the engineered bamboo extending into the flange plate is 2 / 3 of the height of the flange plate.

4. The prefabricated T-beam according to any one of claims 1 to 3, characterized in that: The material of the engineered bamboo is bamboo integrated material or reconstructed bamboo or bamboo-wood composite material.

5. The method for manufacturing a prefabricated T-beam according to claim 1, characterized in that: The steps include: Step 1: Impregnate the FRP sheets with resin, stack the thickness, and splice them into a groove-shaped FRP prefabricated shell after curing and forming, and turn the groove of the FRP prefabricated shell outward and fold the edge; Step 2: Insert several transverse shear screws into the engineered bamboo in an array along the width direction of the engineered bamboo; Step 3: Lift the engineered bamboo and place it in the FRP prefabricated formwork. The engineered bamboo does not contact the bottom surface of the FRP prefabricated formwork, and both ends of the transverse shear screw are against the inner wall of the FRP prefabricated formwork. Step 4: Tie the stirrups in the flange plate, arrange the longitudinal steel bars and tie the stirrups. When tying the stirrups, one long side of the stirrups passes through the FRP prefabricated formwork and engineered bamboo extending into the flange plate; Step 5: Install the angle steel bar between the bending angle of the FRP precast formwork and the stirrups in the flange plate, pass the loop bar through the FRP precast formwork, surround the angle steel bar, tie it with the longitudinal steel bar, and pull up the angle steel bar; Step 6: Set up the flange plate formwork, pour fine aggregate cement-based grouting material between the FRP prefabricated formwork and the engineered bamboo until the top of the web, and then pour coarse aggregate cement-based grouting material in the flange plate formwork. After the cement-based grouting material solidifies, the manufacturing process is completed.

6. The method for manufacturing a prefabricated T-beam according to claim 5, characterized in that: When one long side of the stirrup passes through the FRP prefabricated formwork and the engineered bamboo extending into the flange plate, ensure that the bending position of the FRP prefabricated formwork extending into the flange plate is at 1 / 2 height inside the flange plate, and the engineered bamboo extends into 2 / 3 height of the flange plate.

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