A continuous beam with built-in reinforced bamboo concrete joint and its construction method

Abstract

The present invention relates to a reconstructed bamboo concrete node continuous beam with built-in steel bars and a construction method. In the reconstructed bamboo beam of the present invention, a continuous steel bar is arranged inside the body, thereby improving the rigidity and bearing capacity of the beam. The steel bars at the ends of the beam are extended outward and reliably connected through a straight threaded sleeve to form a continuous beam. The internal force bending moment distribution of the beam is also changed from a simply supported beam to a continuous beam, thereby improving the stress state of the beam and saving materials. Thus, the butt joint of the reconstructed bamboo beam is made into a rigid connection form, the simply supported beam is converted into a continuous beam, the bending moment distribution of the beam is made more reasonable, the material performance is fully utilized, and the purpose of reducing deformation or increasing span is achieved, thereby broadening the engineering application scope of the reconstructed bamboo beam.

Description

Technical Field

[0001] The invention relates to the technical field of bamboo-wood structures in civil engineering, and more particularly to a bamboo-concrete node continuous beam with built-in steel bars and a construction method. Background Art

[0002] Compared with wood, bamboo has the advantages of being green, natural, strong, tough, and having a short growth cycle. It is praised by structural engineers as "plant steel bars". In recent years, various bamboo products for structural engineering have emerged, such as reconstructed bamboo and glued bamboo. Reconstructed bamboo is a new bamboo material that is reorganized and strengthened. That is, the bamboo is processed into long strips of bamboo strips, bamboo fibers, or crushed into bamboo fiber bundles, which are then dried and impregnated with glue, and then dried to the required moisture content. Then, they are laid in a mold and cured at high temperature and high pressure to form a profile. Compared with natural bamboo, reconstructed bamboo has the advantages of being green and environmentally friendly, having a high material utilization rate, high strength, few defects, and being able to be processed into various shapes. It is easy to apply in engineering and has a very bright future in fields such as civil engineering.

[0003] Due to the limitation of raw material size and processing technology, the length of reconstructed bamboo beams generally cannot meet the requirements of continuous beams. In addition, the ability of traditional butt joints to transmit bending moments is weak, resulting in insufficient node stiffness. Therefore, most general reconstructed bamboo beams are simply supported. Under the action of uniformly distributed loads, the bending moment of simply supported beams reaches the maximum value at the mid-span section. From the mid-span to the support, the bending moment generated by the external load gradually decreases. Therefore, except for the mid-span section, the material strength of other sections cannot be fully utilized. Therefore, reconstructed bamboo beams generally first crack at the defect position of the tensile side, and finally brittle failure occurs due to insufficient tensile strength of the material. At this time, the compressive strength of the material has not been fully utilized.

[0004] The deformation of simply supported beams is much larger than that of continuous beams, and the deformation of beams will be further increased due to creep, which will affect the use. In actual projects, the cross-sectional dimensions of many reconstructed bamboo beams are controlled by deformation.

[0005] The existing reconstructed bamboo beams are mostly connected by screws at their nodes. In order to meet the installation requirements, the screw holes are usually 1mm to 2mm larger than the screw diameter. In addition, the pressure-bearing deformation of reconstructed bamboo means that the existing reconstructed bamboo beams can only be made into hinged forms, that is, simply supported beams. This makes the bending moment distribution of the beam very uneven, prone to brittle tensile failure, the material properties cannot be fully utilized, and the deflection is large.

[0006] Therefore, how to provide a bamboo concrete node continuous beam with built-in steel bars is a problem that technicians in this field need to solve urgently. Summary of the invention

[0007] To this end, an object of the present invention is to propose a reconstructed bamboo concrete node continuous beam with built-in steel bars to solve the problem that the reconstructed bamboo beam, as the main bending member in the structure, has a lower elastic modulus than its strength, and when designing the reconstructed bamboo beam, it is often controlled by stiffness, and the strength of the reconstructed bamboo is not fully utilized.

[0008] The present invention provides a bamboo concrete node continuous beam with built-in steel bars, comprising:

[0009] A plurality of reorganized bamboo beams, each of which is embedded with a plurality of mutually parallel steel bars along its length, and the length of the steel bars is greater than the length of the reorganized bamboo beam and extends out of both ends of the reorganized bamboo beam; both ends of the steel bars have external threads;

[0010] The steel bars corresponding to two adjacent reconstructed bamboo beam bodies are connected by straight thread sleeves and then a concrete layer is poured to form a continuous beam connection node.

[0011] Through the above technical solution, it can be known that compared with the prior art, the present invention discloses a continuous beam with built-in steel bars and reconstructed bamboo concrete nodes. A continuous steel bar is arranged in the body of the reconstructed bamboo beam, which improves the rigidity and bearing capacity of the beam. The steel bars at the ends of the beam extend outward and are reliably connected through a straight threaded sleeve to form a continuous beam. The internal force and moment distribution of the beam is also changed from a simply supported beam to a continuous beam, which improves the stress state of the beam and saves materials. Thus, the butt joint of the reconstructed bamboo beam is made into a rigid connection, and the simply supported beam is converted into a continuous beam, so that the bending moment distribution of the beam is more reasonable, the material performance is fully utilized, and the purpose of reducing deformation or increasing span is achieved, thereby broadening the engineering application scope of the reconstructed bamboo beam.

[0012] Furthermore, the invention also includes stirrups, which are tied to the steel bars. After the stirrups are arranged, a concrete node is formed, which improves the rigidity of the node.

[0013] Furthermore, a steel plate is included, the length of which is greater than the length of the continuous beam connection node, which covers the continuous beam connection node and is fixed to the top of two adjacent reconstructed bamboo beam bodies. The integrity of the beam can be increased by arranging the beam top steel plate.

[0014] Furthermore, threaded holes are provided on both ends of the steel plate, and fixing screws are used to fix the steel plate to the top of the reconstructed bamboo beam body through the threaded holes.

[0015] Another object of the present invention is to provide a construction method for a continuous beam with a built-in steel bar reconstructed bamboo concrete node, comprising the following steps: according to the project requirements, a corresponding number of reconstructed bamboo beam bodies are selected, a plurality of prefabricated reconstructed bamboo beam bodies are placed in the same straight line, the steel bars corresponding to two adjacent reconstructed bamboo beam bodies are connected in sequence through a straight threaded sleeve, and then concrete is poured and cured to form a continuous beam connection node.

[0016] Furthermore, the bamboo tube is split into strips, the split bamboo strips are pressed into bamboo strips, and the strips are bundled into bamboo fiber bundles and then dipped in glue for later use. The position and number of the steel bars in the reconstructed bamboo beam are designed, the steel bars are wrapped around the bamboo fibers and then dipped in glue and dried. The steel bars are placed at the preset position of the mold, the fiber bundles dipped in glue are laid, and then the whole is hot-pressed to form the reconstructed bamboo beam.

[0017] Furthermore, after the straight threaded sleeve is connected to the steel bars corresponding to two adjacent reorganized bamboo beam bodies, the steel bars corresponding to one end of each reorganized bamboo beam body are fixed by stirrups.

[0018] Furthermore, after pouring and curing the concrete, a steel plate is covered on the top of the continuous beam connection node, and both ends of the steel plate are fixed to the tops of two adjacent reconstructed bamboo beams by screws.

[0019] It can be seen from the above technical scheme that, compared with the prior art, the present invention discloses a construction method for a continuous beam with a built-in reinforced reconstructed bamboo concrete node, which makes the butt joints of the reconstructed bamboo beams into a rigid connection, converts the simply supported beams into continuous beams, makes the bending moment distribution of the beams more reasonable, makes full use of the material properties, and achieves the purpose of reducing deformation or increasing span, thereby broadening the engineering application scope of the reconstructed bamboo beams. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0021] Figure 1 The accompanying drawing is a schematic structural diagram of a continuous beam with built-in reinforced bamboo concrete nodes provided by the present invention;

[0022] Figure 2 The accompanying drawings show a schematic diagram of the connection of steel bars, straight thread sleeves and stirrups;

[0023] Figure 3 The accompanying drawings show a schematic diagram of the structure of the reconstructed bamboo beam body;

[0024] Figure 4 The accompanying drawings show a schematic diagram of an embodiment of adding a steel plate;

[0025] Figure 5 The accompanying drawing shows a schematic diagram of the structure of the steel plate;

[0026] In the figure: 100-first reorganized bamboo beam body, 101-first steel bar, 200-second reorganized bamboo beam body, 201-second steel bar, 300-concrete layer, 400-straight threaded sleeve, 500-hoop, 600-steel plate, 601-threaded hole. DETAILED DESCRIPTION

[0027] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0028] In the description of the present invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0030] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Since the reconstructed bamboo beam is the main bending member in the structure, its elastic modulus is relatively low compared with its strength. When designing the reconstructed bamboo beam, the stiffness is often controlled, and the strength of the reconstructed bamboo is not fully utilized, and it is still a simply supported beam. To this end, the embodiment of the present invention discloses a continuous beam with built-in reinforced reconstructed bamboo concrete nodes, see the attached Figure 1-3, specifically comprising: two reorganized bamboo beam bodies, one is a first reorganized bamboo beam body 100, and the other is a second reorganized bamboo beam body 200, each reorganized bamboo beam body is embedded with a plurality of first steel bars 101 or second steel bars 201 arranged in parallel along its length direction, and the length of the first steel bars 101 or the second steel bars 201 is greater than the first reorganized bamboo beam body 100 and the second reorganized bamboo beam body 200, and extends out of both ends of the reorganized bamboo beam body; both ends of the steel bars 101 have external threads; straight thread sleeves 400, and the steel bars 101 corresponding to the two adjacent reorganized bamboo beam bodies are connected by straight thread sleeves 400 and then poured with a concrete layer 300 to form a continuous beam connection node. The reorganized bamboo beam body is provided with a continuous steel bar, which improves the stiffness and bearing capacity of the beam, and the steel bars at the ends of the beam extend outward and are reliably connected through straight thread sleeves to form a continuous beam, and the internal force and bending moment distribution of the beam is also changed from a simply supported beam to a continuous beam, which improves the stress state of the beam, thereby saving materials. Therefore, the butt joints of the reconstructed bamboo beams are made into rigid joints, and the simply supported beams are transformed into continuous beams, so that the bending moment distribution of the beams is more reasonable, the material properties are fully utilized, and the purpose of reducing deformation or increasing span is achieved, thereby broadening the engineering application scope of the reconstructed bamboo beams.

[0032] In one embodiment of the present invention, stirrups 500 are further included, and the stirrups 500 are tied to the first steel bar and the second steel bar respectively. After the stirrups are arranged, a concrete node is formed, which improves the rigidity of the node.

[0033] In some other embodiments of the present invention, see the attached Figure 4 and 5 , and also includes a steel plate 600, the length of which is greater than the length of the continuous beam connection node, which covers the continuous beam connection node and is fixed to the top of two adjacent reconstructed bamboo beams; the integrity of the beam can be increased by arranging the beam top steel plate.

[0034] Specifically, threaded holes 601 are provided on both ends of the steel plate 600 , and fixing screws are passed through the threaded holes 601 to fix the steel plate 600 to the top of the reconstructed bamboo beam body.

[0035] The present invention also provides a construction method for a continuous beam with a built-in steel bar reconstructed bamboo concrete node, comprising the following steps: according to the project requirements, a corresponding number of reconstructed bamboo beam bodies are selected, a plurality of prefabricated reconstructed bamboo beam bodies are placed in the same straight line, the steel bars corresponding to two adjacent reconstructed bamboo beam bodies are connected in sequence through a straight threaded sleeve, and then concrete is poured and cured to form a continuous beam connection node.

[0036] The bamboo tube is split into strips, the split bamboo strips are pressed into bamboo strips, and then bundled into bamboo fiber bundles and dipped in glue for later use. The position and number of steel bars in the reconstructed bamboo beam are designed, the steel bars are wrapped around the bamboo fibers and then dipped in glue and dried. The steel bars are placed at the preset position of the mold, the fiber bundles dipped in glue are laid, and then the whole is hot-pressed to form the reconstructed bamboo beam.

[0037] Advantageously, after the straight thread sleeve connects the steel bars corresponding to the two adjacent bamboo beam bodies, the steel bars corresponding to one end of each bamboo beam body are fixed by stirrups. The specific parameters such as the type, quantity, and spacing of the stirrups are designed and selected according to actual needs.

[0038] More advantageously, after pouring concrete for 7-14 days, when it reaches a certain strength, a steel plate can be covered on the top of the continuous beam connection node. The thickness of the steel plate refers to the bearing capacity calculation formula Z = k for the pin-type fasteners in the pin connection of the wooden structure. min t s df es To determine, where k min It indicates the minimum effective length coefficient of the pin groove under pressure, which is related to the thickness of the steel plate; d indicates the screw diameter; f es Indicates the standard value of the bearing strength of the pin groove of the component. The thickness of the steel plate, the size of the reconstructed bamboo, the type of screws and their mechanical properties jointly affect the bearing capacity and failure mode of the component. The two ends of the steel plate are fixed to the top of the two adjacent reconstructed bamboo beams by screws.

[0039] The present invention is used to improve the node stiffness of the reconstructed bamboo beam, change the stress state of the beam, and transform it from a simply supported beam to a continuous beam. Compared with the simply supported beam, the bending moment distribution of the continuous beam is more uniform, and the material properties of the reconstructed bamboo can be fully utilized to avoid brittle tensile damage, and the purpose of reducing deformation or increasing span can be achieved, thereby broadening the engineering application scope of the reconstructed bamboo beam. In the process of processing a single-span reconstructed bamboo beam, the steel bars are directly built in without grooving or secondary processing. The steel bars extending outward from the beam end are reliably connected by straight threads, and concrete is poured after stirrups are arranged. Steel cover plates can be added to transmit tensile force as appropriate. The concrete nodes formed in this way can ensure their stiffness, and the nodes can transmit bending moments, thus finally forming a continuous beam.

[0040] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0041] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A construction method for a continuous beam with built-in reinforced bamboo concrete nodes, characterized in that: The method comprises the following steps: selecting a corresponding number of reassembled bamboo beams according to the engineering requirements, placing a plurality of prefabricated reassembled bamboo beams in the same straight line, sequentially connecting the steel bars corresponding to two adjacent reassembled bamboo beams through straight threaded sleeves, and then pouring concrete and curing to form a continuous beam connection node; wherein, a continuous steel bar is arranged in the reassembled bamboo beam, and the steel bars at the beam ends extend outward and are connected through straight threaded sleeves to form a continuous beam; The bamboo tube is split into strips, the split bamboo strips are pressed into bamboo strips, and the bamboo fiber bundles are bundled and then dipped in glue for later use, the position and number of the steel bars in the reconstructed bamboo beam are designed, the steel bars are wrapped around the bamboo fibers and then dipped in glue and dried, the steel bars are placed at the preset position of the mold, the fiber bundles dipped in glue are laid, and then the whole is hot-pressed to form the reconstructed bamboo beam body; After pouring concrete and curing, a steel plate is covered on the top of the continuous beam connection node, and both ends of the steel plate are fixed to the top of the two adjacent reconstructed bamboo beams by screws.

2. The construction method of a continuous beam with built-in steel bars and reconstructed bamboo concrete nodes according to claim 1 is characterized in that: After the straight thread sleeve is connected to the steel bars corresponding to two adjacent reorganized bamboo beam bodies, the steel bars corresponding to one end of each reorganized bamboo beam body are fixed by stirrups.

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