Recombined bamboo-concrete continuous beam and preparation method thereof

Abstract

The invention belongs to the technical field of civil engineering, and particularly discloses a recombined bamboo-concrete continuous beam and a preparation method thereof.The recombined bamboo-concrete continuous beam comprises two recombined bamboo beams, a concrete beam is poured between the two recombined bamboo beams to form a base beam, and the recombined bamboo-concrete continuous beam further comprises at least one first steel bar assembly; the first steel bar assembly comprises a first steel pipe, a first steel bar and a first anchoring part. The first steel pipe is arranged in the recombined bamboo beam in the beam length direction of the recombined bamboo beam. The first steel bars penetrate through the first steel pipes. The first anchoring parts are arranged at the two ends of the first steel bars and used for fixing the two ends of the first steel bars to the ends, away from the concrete beam, of the two recombined bamboo beams correspondingly, and the anchoring degree of the ends of the first steel bars is increased through the first anchoring parts so that prestress can be applied to the base beam. The preparation method comprises the steps of preparation of the recombined bamboo beam, installation of the reinforcing steel bars, preparation of the concrete beam and application of prestress. The rigidity of the recombined bamboo-concrete continuous beam is effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of civil engineering, specifically to the technical field of bamboo-concrete composite structures in civil engineering, and particularly to a reconstituted bamboo-concrete continuous beam and a preparation method thereof. Background Art

[0002] Green economy has become the trend of human development and has become a consensus around the world.

[0003] Bamboo-wood structure buildings have the natural advantage of "strong carbon fixation ability". Reconstructed bamboo is a new bamboo material that is reorganized and strengthened. The bamboo is processed into long strips of bamboo strips, bamboo fibers or crushed into bamboo fiber bundles, dried and impregnated with glue, and then dried to the required moisture content. It is then 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, high material utilization, high strength, few defects, and can be processed into various shapes. It is easy to apply in engineering and has a very bright future in civil engineering and other fields.

[0004] Recombined bamboo is one of the most common bamboo composite materials, and is particularly suitable for important load-bearing components such as beams and columns. However, as an outrigger component, recombined bamboo has low cross-sectional stiffness, large deflection under bending load, and limited spanning capacity, which leads to a low elastic modulus of the recombined bamboo beam. Therefore, when designing recombined bamboo beams, the stiffness is often controlled, which results in the strength of the recombined bamboo not being fully utilized. When checking the bearing capacity of the recombined bamboo beam, a larger cross-sectional size is often required to meet its stiffness requirements. This not only causes material waste and increases the weight of the structure itself, but also makes it difficult to use in areas with smaller cross-sectional requirements, resulting in a reduced range of matching use. If the cross-sectional size of the recombined bamboo beam remains unchanged, its stiffness cannot meet the required bearing requirements. Summary of the invention

[0005] In view of the above-mentioned problems, the object of the present invention is to provide a reconstructed bamboo-concrete continuous beam and a preparation method thereof, which can effectively improve the stiffness under the premise that the cross-sectional size of the reconstructed bamboo beam remains unchanged.

[0006] The technical solution of the present invention is: a reconstructed bamboo-concrete continuous beam, comprising:

[0007] Two reconstructed bamboo beams, with a concrete beam cast between the two reconstructed bamboo beams to form a base beam;

[0008] Also included is at least one first reinforcement assembly, the first reinforcement assembly comprising:

[0009] The first steel pipe is arranged inside the reconstructed bamboo beam along the length direction of the reconstructed bamboo beam;

[0010] A first steel bar is inserted into the first steel pipe;

[0011] The first anchors are arranged at both ends of the first steel bar and are used to fix the two ends of the first steel bar to the ends of the two reconstructed bamboo beams away from the concrete beam respectively. The first anchors are used to increase the anchorage degree of the ends of the first steel bar to apply prestress to the base beam.

[0012] Furthermore, there are multiple groups of the first steel bar assemblies, and at least one of the multiple groups of the first steel bar assemblies is used to apply prestress to the base beam.

[0013] Furthermore, a second steel bar assembly is also included, and the second steel bar assembly includes:

[0014] The second steel pipe is arranged inside the reconstructed bamboo beam along the length direction of the reconstructed bamboo beam;

[0015] The second steel bar is inserted into the second steel pipe;

[0016] The second anchoring piece is provided at both ends of the second steel bar and is used to fix the two ends of the second steel bar to the two ends of the same reconstructed bamboo beam respectively. The second anchoring piece is used to increase the anchorage degree of the end of the second steel bar to apply prestress to the reconstructed bamboo beam.

[0017] Furthermore, the cross-section of the reconstructed bamboo beam is rectangular, and the thickness of the first steel pipe and the second steel pipe from the side of the bamboo beam matrix is ​​H, and H is ≥ 20 mm.

[0018] Furthermore, the spacing between the first steel pipes, between the second steel pipes, and between the first steel pipe and the second steel pipe is L, and L≥25mm.

[0019] Furthermore, an anchor plate is provided on a side surface of the reconstructed bamboo beam away from the concrete beam, and ends of the first steel bar and the second steel bar are anchored on the anchor plate.

[0020] A method for preparing a reconstructed bamboo-concrete continuous beam comprises the following steps:

[0021] S1. Preparation of reconstituted bamboo beams

[0022] The bamboo tube is split into strips, pressed into bamboo strips, and then bundled into bamboo fiber bundles and dipped in glue. The steel tube is pre-treated, and then the steel tube is wrapped around the bamboo fiber bundle and hot-pressed to form a reconstructed bamboo beam with a built-in steel tube.

[0023] S2. Installation of steel bars

[0024] Place two reconstructed bamboo beams in a straight line, with the spacing area forming a connection gap; then pass the steel bar through the steel pipe, and anchor the end of the steel bar to the reconstructed bamboo beam through the anchor;

[0025] S3. Preparation of concrete beams

[0026] The formwork and support are built at the connection gap, and then the concrete is poured. Finally, the formwork is removed and the concrete is cured to form a concrete beam;

[0027] S4. Application of prestress

[0028] The anchorage degree of the steel bar ends on the reconstructed bamboo beams is increased by adjusting the anchors, thereby achieving prestressing of the steel bars.

[0029] Furthermore, in step S1, the steel pipe is wrapped around the bamboo fiber bundle, impregnated with glue and dried, and then hot-pressed to form a reconstructed bamboo beam with a built-in steel pipe.

[0030] Furthermore, the specific steps of pre-treating the steel pipe in step S1 are: using a shot blasting process to increase the surface roughness of the steel pipe.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention can achieve the purpose of applying prestress to the reconstructed bamboo-concrete continuous beam through the first steel bar assembly, so that its ultimate bearing capacity increases with the increase of the prestress level, and the rigidity of the reconstructed bamboo-concrete continuous beam is effectively improved.

[0033] The rigidity of the beam is improved by combining the reconstructed bamboo beam with the concrete beam. The reconstructed bamboo beam of the present invention arranges a steel pipe in the bamboo beam matrix, and further connects the steel bars by passing through the steel pipe and anchoring them by anchoring pieces, so that a continuous beam can be formed, thereby enhancing the rigidity of the reconstructed bamboo beam.

[0034] Among them, placing a steel pipe group inside the bamboo beam matrix can improve the stiffness of the reconstructed bamboo beam. This reinforcement method is convenient and effective. Placing the steel pipe inside the bamboo beam matrix can avoid corrosion of the steel pipe and ensure the safety and durability of the component. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the external structure of the present invention;

[0036] Figure 2 is an internal cross-sectional view of Embodiment 1 of the present invention;

[0037] Figure 3 It is a schematic diagram of the internal partial structure of Example 1 of the present invention;

[0038] Figure 4 is a cross-sectional view of the present invention;

[0039] Figure 5 is an internal cross-sectional view of Embodiment 2 of the present invention;

[0040] Figure 6 It is a schematic diagram of the internal partial structure of Example 2 of the present invention.

[0041] Among them, 1-reconstructed bamboo beam, 2-concrete beam, 3-first steel bar assembly, 31-first steel pipe, 32-first steel bar, 33-first anchor, 4-second steel bar assembly, 41-second steel pipe, 42-second steel bar, 43-second anchor, 5-anchor plate. DETAILED DESCRIPTION

[0042] The following is combined with Figure 1 To the attached Figure 6 , the specific embodiments of the present invention are described in detail. In the description of the present invention, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships 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 limiting the present invention.

[0043] 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, unless otherwise specified, "plurality" means two or more.

[0044] Example 1

[0045] like Figure 1 , Figure 2 , Figure 3 A reconstructed bamboo-concrete continuous beam shown includes two reconstructed bamboo beams 1 and at least one first steel bar assembly 3. A concrete beam 2 is cast between the two reconstructed bamboo beams 1 to form a base beam. The first steel bar assembly 3 includes a first steel pipe 31, a first steel bar 32 and a first anchor 33. The first steel pipe 31 is arranged in the reconstructed bamboo beam 1 along the length direction of the reconstructed bamboo beam 1. The first steel bar 32 is inserted into the first steel pipe 31. The first anchor 33 is arranged at both ends of the first steel bar 32, and is used to fix the two ends of the first steel bar 32 to one end of the two reconstructed bamboo beams 1 away from the concrete beam 2, respectively, and the anchorage degree of the end of the first steel bar 32 is increased by the first anchor 33 to apply prestress to the base beam.

[0046] The ends of the first steel bar 32 are provided with external threads, and the first anchor 33 adopts a straight thread sleeve, and the first anchor 33 is threadedly connected to the end of the first steel bar 32. The tensile stress of the first steel bar 32 is controlled by the actual number of turns of the straight thread sleeve, so as to achieve the application of prestress to the base beam.

[0047] The reconstructed bamboo-concrete continuous beam corresponding to the structure is suitable for being arranged in a position subject to repeated loads, that is, positive and negative bending moments may occur in the middle of the reconstructed bamboo-concrete continuous beam, so that the first steel bar 32 passes through the concrete beam 2. Due to the tensile properties of the first steel bar 32, the reconstructed bamboo-concrete continuous beam can present a better stress state.

[0048] Preferably, Figure 2 , Figure 3 As shown, there are multiple groups of first steel bar assemblies 3, and at least one of the multiple groups of first steel bar assemblies 3 is used to apply prestress to the base beam. In this embodiment, there are 4 groups of first steel bar assemblies 3, and 2 groups of first steel bar assemblies 3 are used to apply prestress to the base beam.

[0049] The method for preparing the reconstructed bamboo-concrete continuous beam proposed in this embodiment comprises the following steps:

[0050] S1. Preparation of recombinant bamboo beam 1

[0051] The bamboo tube is split into strips, pressed into bamboo strips, and bundled into bamboo fiber bundles and then dipped in glue. The first steel tube 31 is pre-treated, and then the first steel tube 31 is wrapped around the bamboo fiber bundle and hot-pressed to form a reconstructed bamboo beam 1 with the first steel tube 31 built in. The first steel tube 31 is formed by direct bonding and hot pressing, without the need for grooving or secondary processing, so the integrity of the beam can be guaranteed.

[0052] S2. Installation of the first reinforcement 32

[0053] Place two reconstructed bamboo beams 1 in a straight line, with the spacing area forming a connection gap; then pass the first steel bar 32 through the first steel pipe 31, and anchor the end of the first steel bar 32 on the reconstructed bamboo beam 1 through the first anchor 33;

[0054] S3. Preparation of concrete beam 2

[0055] Formwork and brackets are built at the connection gap, and then concrete is poured. Finally, the formwork is removed and the concrete is cured to form a concrete beam 2;

[0056] S4. Application of prestress

[0057] By adjusting the first anchor 33, the anchorage degree of the end of the first steel bar 32 on the reconstructed bamboo beam 1 is increased, so that prestress is applied to the first steel bar 32; specifically, the tensile stress of the first steel bar 32 is controlled by the actual number of turns of screwing the straight threaded sleeve, so as to apply prestress to the base beam.

[0058] Preferably, in step S1, the first steel tube 31 is wrapped around the bamboo fiber bundle, impregnated with glue and dried, and then hot-pressed to form a reconstructed bamboo beam 1 with the first steel tube 31 built therein.

[0059] Preferably, the specific steps of pre-treating the first steel pipe 31 in step S1 are: performing a shot blasting process on the surface of the first steel pipe 31 to increase its surface roughness.

[0060] Example 2

[0061] The difference from Example 1 is:

[0062] Preferably, Figure 5 , Figure 6 , and also includes a second steel bar assembly 4, which includes a second steel pipe 41, a second steel bar 42 and a second anchor 43.

[0063] The second steel tube 41 is arranged in the reorganized bamboo beam 1 along the length direction of the reorganized bamboo beam 1. The second steel bar 42 is passed through the second steel tube 41. The second anchoring pieces 43 are arranged at both ends of the second steel bar 42, and are used to fix the two ends of the second steel bar 42 to the two ends of the same reorganized bamboo beam 1, respectively. The second anchoring pieces 43 increase the anchorage degree of the end of the second steel bar 42 to apply prestress to the reorganized bamboo beam 1.

[0064] The ends of the second steel bars 42 are provided with external threads, and the second anchors 43 are nuts, which are threadedly connected to the ends of the second steel bars 42. The tensile stress of the second steel bars 42 is controlled by the actual number of turns of the straight nuts, so as to achieve the application of prestress to the base beam.

[0065] In this embodiment, there are two groups of first steel bar assemblies 3 and two groups of second steel bar assemblies 4 . No prestress is applied to the first steel bar assemblies 3 , while prestress is applied to the second steel bar assemblies 4 .

[0066] The reconstructed bamboo-concrete continuous beam corresponding to this structure is suitable for being arranged in the middle of the beam where only negative bending moment exists. It is subjected to a small repeated load, so it is not necessary for all the second steel bars 42 to pass through and connect the concrete beam 2.

[0067] Preferably, Figure 4 As shown, the cross section of the reconstructed bamboo beam 1 is rectangular, and the thickness of the first steel tube 31 and the second steel tube 41 from the side of the bamboo beam base 11 is H, H≥20mm, and H is 20mm in this embodiment.

[0068] Preferably, the spacing between the first steel tubes 31 , between the second steel tubes 41 , and between the first steel tube 31 and the second steel tube 41 is L, and L≥25 mm.

[0069] Preferably, an anchor plate 5 is provided on the side surface of the reconstructed bamboo beam 1 away from the concrete beam 2, and the ends of the first steel bar 32 and the second steel bar 42 are anchored on the anchor plate 5. The setting of the anchor plate 5 can effectively prevent local pressure on the bamboo beam matrix 1 when prestress is applied.

[0070] The method for preparing the reconstructed bamboo-concrete continuous beam proposed in this embodiment comprises the following steps:

[0071] S1. Preparation of recombinant bamboo beam 1

[0072] The bamboo tube is split into strips, pressed into bamboo strips, and then bundled into bamboo fiber bundles and dipped in glue. The first steel tube 31 and the second steel tube 41 are pre-treated, and then the first steel tube 31 and the second steel tube 41 are wrapped around the bamboo fiber bundle and hot-pressed to form a reconstructed bamboo beam 1 with the first steel tube 31 and the second steel tube 41 built therein;

[0073] S2. Installation of the first steel bar 32 and the second steel bar 42

[0074] Place two reconstructed bamboo beams 1 in a straight line, with the spacing area forming a connection gap; then, the first steel bar 32 and the second steel bar 42 are respectively passed through the first steel pipe 31 and the second steel pipe 41, and the ends are anchored on the reconstructed bamboo beam 1 through the first anchor 33 and the second anchor 43 respectively;

[0075] S3. Preparation of concrete beam 2

[0076] Formwork and brackets are built at the connection gap, and then concrete is poured. Finally, the formwork is removed and the concrete is cured to form a concrete beam 2;

[0077] S4. Application of prestress

[0078] By adjusting the second anchoring piece 43 , the anchorage degree of the end of the second steel bar 42 on the reconstructed bamboo beam 1 is increased, so that prestress is applied to the second steel bar 42 .

[0079] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and does not limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the protection scope of the present invention.

Claims

1. A reconstructed bamboo-concrete continuous beam, comprising: Two reorganized bamboo beams (1), a concrete beam (2) is cast between the two reorganized bamboo beams (1) to form a base beam; The invention is characterized in that it further comprises at least one first steel bar assembly (3), wherein the first steel bar assembly (3) comprises: A first steel pipe (31) is arranged inside the reorganized bamboo beam (1) along the length direction of the reorganized bamboo beam (1); A first steel bar (32) is inserted into the first steel pipe (31); The first anchoring piece (33) is arranged at both ends of the first steel bar (32) and is used to fix the two ends of the first steel bar (32) to one end of the two reconstructed bamboo beams (1) away from the concrete beam (2), respectively. The first anchoring piece (33) increases the anchorage degree of the end of the first steel bar (32) so as to apply prestress to the base beam.

2. The reconstructed bamboo-concrete continuous beam according to claim 1, characterized in that: There are multiple groups of the first steel bar components (3), and at least one of the multiple groups of first steel bar components (3) is used to apply prestress to the base beam.

3. The reconstructed bamboo-concrete continuous beam according to claim 1, characterized in that: The invention also comprises a second steel bar assembly (4), wherein the second steel bar assembly (4) comprises: The second steel pipe (41) is arranged inside the reorganized bamboo beam (1) along the length direction of the reorganized bamboo beam (1); A second steel bar (42) is inserted into the second steel pipe (41); The second anchoring piece (43) is provided at both ends of the second steel bar (42) and is used to fix the two ends of the second steel bar (42) to the two ends of the same reconstructed bamboo beam (1) respectively. The second anchoring piece (43) increases the anchorage degree of the end of the second steel bar (42) so as to apply prestress to the reconstructed bamboo beam (1).

4. The reconstructed bamboo-concrete continuous beam according to claim 3, characterized in that: The cross section of the reconstructed bamboo beam (1) is rectangular, and the thickness of the first steel pipe (31) and the second steel pipe (41) from the side of the bamboo beam base (11) is H, and H is ≥ 20 mm.

5. The reconstructed bamboo-concrete continuous beam according to claim 3, characterized in that: The spacing between the first steel tubes (31), between the second steel tubes (41), and between the first steel tube (31) and the second steel tube (41) is L, and L is ≥ 25 mm.

6. The reconstructed bamboo-concrete continuous beam according to claim 3, characterized in that: An anchor plate (5) is provided on the side surface of the reconstructed bamboo beam (1) away from the concrete beam (2), and the ends of the first steel bar (32) and the second steel bar (42) are anchored on the anchor plate (5).

7. A method for preparing a reconstructed bamboo-concrete continuous beam, characterized in that: The following steps are involved: S1. Preparation of reconstituted bamboo beams The bamboo tube is split into strips, pressed into bamboo strips, and then bundled into bamboo fiber bundles and dipped in glue. The steel tube is pre-treated, and then the steel tube is wrapped around the bamboo fiber bundle and hot-pressed to form a reconstructed bamboo beam with a built-in steel tube. S2. Installation of steel bars Place two reconstructed bamboo beams in a straight line, with the spacing area forming a connection gap; then pass the steel bar through the steel pipe, and anchor the end of the steel bar to the reconstructed bamboo beam through the anchor; S3. Preparation of concrete beams The formwork and support are built at the connection gap, and then the concrete is poured. Finally, the formwork is removed and the concrete is cured to form a concrete beam; S4. Application of prestress The anchorage degree of the steel bar ends on the reconstructed bamboo beams is increased by adjusting the anchors, thereby achieving prestressing of the steel bars.

8. The method for preparing a reconstructed bamboo-concrete continuous beam according to claim 7, characterized in that: In step S1, the steel pipe is wrapped around the bamboo fiber bundle, impregnated with glue and dried, and then hot-pressed to form a reconstructed bamboo beam with a built-in steel pipe.

9. The method for preparing a reconstructed bamboo-concrete continuous beam according to claim 7, characterized in that: The specific steps of pre-treating the steel pipe in step S1 are: using a shot blasting process to increase the surface roughness of the steel pipe.

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