Concrete structure and method for manufacturing a concrete structure

Abstract

This invention proposes a concrete structure reinforced with bamboo reinforcing bars, which reduces the effort required during manufacturing, and a method for manufacturing this concrete structure. [Solution] The concrete structure 1 comprises a concrete section 2 and a plurality of reinforcing bars 3 embedded in the concrete section 2. At least a portion of the plurality of reinforcing bars 3 consists of a hybrid reinforcing bar 32, which comprises a bent reinforcing bar 34 and bamboo rods 33 attached to both ends of the reinforcing bar 34, which are made by cutting bamboo along the direction of the fiber of the rod and then cutting it along the extension direction of the reinforcing bar 34.

Description

Technical Field

[0001] The present invention relates to a concrete structure and a method for manufacturing the same.

Background Art

[0002] In recent years, efforts to achieve sustainable development goals (SDGs) have been made in various fields, and in the concrete field as well, technologies for reducing environmental impact are desired. Patent Document 1 discloses a concrete secondary product using bamboo, which is a natural material, as a reinforcing bar. By using such a concrete secondary product, the environmental impact can be reduced.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The reinforcing bars of a concrete structure may be bent depending on the location. For example, at the corner of the bottom plate and the side wall, reinforcing bars bent in an L-shape or a U-shape are arranged. Techniques for bending steel bars with a predetermined bending radius have been established. On the other hand, it takes time to bend bamboo into a predetermined shape.

[0005] From such a perspective, an object of the present invention is to propose a concrete structure reinforced with reinforcing bars using bamboo, which can reduce the labor during manufacturing, and a method for manufacturing this concrete structure.

Means for Solving the Problems

[0006] The concrete structure of the present invention for solving the aforementioned problems comprises a concrete section and a plurality of reinforcing bars embedded in the concrete section. At least a portion of the plurality of reinforcing bars comprises a bamboo rod, which is made by cutting bamboo along the direction of the fibers of the pole and then cutting it, and a bent reinforcing bar, with the bamboo rod fixed to the end of the reinforcing bar in the direction of extension of the reinforcing bar.

[0007] Furthermore, the method for manufacturing a concrete structure according to the present invention comprises a preparation step of preparing reinforcing bars, a reinforcing bar assembly step of assembling the reinforcing bars, and a concrete pouring step of pouring concrete into a formwork. In the preparation step, a hybrid reinforcing bar is formed by connecting bamboo rods, which are made by cutting bamboo along the direction of the fibers of the bamboo shaft, with bent reinforcing bars. In the reinforcing bar assembly step, bamboo reinforcing bars, which are made by cutting bamboo along the direction of the fibers of the bamboo shaft, are arranged in a direction intersecting the hybrid reinforcing bar and combined in a grid or cage shape. The hybrid reinforcing bar may be formed by bonding the reinforcing bar and the bamboo rod, or by fixing the reinforcing bar and the bamboo rod with binding wire or the like.

[0008] According to the present invention, by using a hybrid reinforcing bar in which a bamboo rod is fixed to a bent steel bar as a reinforcing bar placed at the corners of a concrete structure, the effort required to manufacture the reinforcing bar can be reduced. In other words, since steel bars are used in the parts where bending is required, the effort required to manufacture can be reduced compared to bending the bamboo rod. Furthermore, since reinforcing bars primarily made of bamboo are lightweight, it becomes possible to reduce the weight of concrete structures, making them easier to handle on site. [Effects of the Invention]

[0009] According to the concrete structure and method for manufacturing the concrete structure of the present invention, it is possible to reduce the effort required during the manufacturing process for a concrete structure reinforced with reinforcing bars made of bamboo. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows a concrete structure according to this embodiment, where (a) is a cross-sectional view and (b) is a side view. [Figure 2] (a) is a perspective view showing the hybrid reinforcement of this embodiment, (b) is a perspective view showing the hybrid reinforcement of another embodiment, and (c) is a perspective view showing the hybrid reinforcement of another embodiment. [Figure 3] (a) is a perspective view showing the intersection of reinforcing bars in this embodiment, and (b) is a perspective view showing the intersection of reinforcing bars in another embodiment. [Figure 4] (a) is a cross-sectional view of a bamboo stick, (b) is a cross-sectional view showing the bamboo stick before it is taken from the pole, and (c) is a cross-sectional view showing the bamboo stick before processing. [Modes for carrying out the invention]

[0011] In this embodiment, a U-shaped channel (concrete structure 1) used for roadside ditches, etc., will be described. The concrete structure 1 is a so-called secondary product manufactured in a factory or the like. As shown in Figures 1(a) and (b), the concrete structure 1 comprises a concrete section 2 and reinforcing bars 3 embedded in the concrete section 2.

[0012] The concrete section 2 consists of concrete containing cement, aggregate, admixtures, water-reducing agents, etc. There are no restrictions on the type or mix of materials used in the concrete. As shown in Figure 1(a), the concrete section 2 of this embodiment has a U-shape in cross-section.

[0013] The reinforcing bars 3 are embedded in the concrete section 2 in a cage-like assembled state. In this embodiment, bamboo reinforcing bars 31 and hybrid reinforcing bars 32 are used as the reinforcing bars 3. The bamboo reinforcement bars 31 consist of bamboo rods 33 that are made by cutting bamboo along the direction of the fibers of the rod and then cutting them. There are no restrictions on the type of bamboo used to make the bamboo rods 33; for example, Madake, Moso bamboo, Hachiku, Onnadake, etc., can be used. The width of the bamboo rods 33 that make up the reinforcement bars 3 shall be 25 mm or less and shall be appropriately determined based on the strength of the bamboo rods 33 (bamboo material) and the live load strength acting on the reinforcement bars 3.

[0014] The hybrid reinforcement bar 32 consists of bamboo rods 33, which are made by cutting bamboo along the direction of the fibers of the rod and then cutting them, and bent steel bars 34. Bamboo rods 33 are fixed to both ends of the steel bars 34 along the extension direction of the steel bars 34. In this embodiment, the steel bars 34 and bamboo rods 33 are fixed together with binding wire 5. The steel bars 34 and bamboo rods 33 may be glued together or fixed together with jigs or other fixtures other than the binding wire 5. In this embodiment, the hybrid reinforcement bar 32 is U-shaped by combining a pair of steel bars 34, 34 and three bamboo rods 33, 33, 33. The shape of the hybrid reinforcement bar 32 is not limited and may be L-shaped, for example.

[0015] As shown in Figure 2(a), in this embodiment, the hybrid reinforcing bar 32 has the bamboo rod 33 attached to the outside of the reinforcing bar 34 (the outer surface side of the U-shaped channel when installed in the U-shaped channel) and fixed in place. The arrangement of the bamboo rod 33 can be appropriately determined based on the thickness, shape, and structural requirements of the members. For example, as shown in Figure 2(b), the bamboo rod 33 may be attached to the inside of the reinforcing bar 34 (the inner surface side of the U-shaped channel), or as shown in Figure 2(c), the bamboo rod 33 may be attached to the middle of the reinforcing bar 34 in the inward and outward directions.

[0016] As shown in Figures 1(a) and (b), the bamboo reinforcement bars 31 are arranged along the axial direction of the U-shaped channel, with multiple bars placed at predetermined intervals in the circumferential direction of the U-shaped channel. On the other hand, the hybrid reinforcement bars 32 are arranged in a direction intersecting the axial direction of the U-shaped channel, with multiple bars placed at predetermined intervals in the axial direction of the U-shaped channel. In other words, the bamboo reinforcement bars 31 and the hybrid reinforcement bars 32 are assembled in a grid-like (cage-like) structure.

[0017] At the intersection of the bamboo reinforcing bar 31 and the hybrid reinforcing bar 32, as shown in Fig. 3(a), a fixture 4 penetrating both reinforcing bars 3, 3 is inserted. The fixture 4 of this embodiment is a so-called bamboo screw (drill screw for bamboo), and at the intersection of bamboo rods 33, it has a length that penetrates at least one of the bamboo rods 33 and the tip is inserted into the other bamboo rod 33. As shown in Fig. 3(b), the fixture 4 may have a length that penetrates both bamboo rods 33, 33. When the fixture 4 protrudes from the bamboo rod 33, the adhesion performance to the concrete increases. Further, the fixture 4 is not limited to a bamboo screw, and may be, for example, a binding wire or a bamboo skewer. When using a binding wire or a bamboo skewer, etc., an adhesive or a displacement prevention agent may be used in combination to suppress displacement due to loosening or the like.

[0018] Here, as shown in Fig. 4(a), the back surface 36, which is the surface opposite to the skin (surface) 35 of the bamboo rod 33, is processed into a flat surface, and the side surfaces 37, 37 are processed into planes orthogonal to the back surface 36. That is, the bamboo rod 33 is formed in a belt shape having a surface (skin 35) composed of a curved surface (cylindrical surface) and a back surface 36 composed of a flat surface.

[0019] At the intersection of the bamboo reinforcing bar 31 and the hybrid reinforcing bar 32, as shown in Fig. 3(a), the fixture 4 is inserted in a state where the back surfaces 36 of the bamboo rods 33 are in contact with each other. In the hybrid reinforcing bar 32 of this embodiment, the bamboo rod 33 and the reinforcing bar 34 are tied or adhered in a state where the back surface 36 of the bamboo rod 33 is in contact with the reinforcing bar 34, and the skin 35 is arranged on the outer surface side (tensile bending side) of the U-shaped groove (see Figs. 2(a)(b)). On the other hand, the bamboo reinforcing bar 31 is arranged (reinforcement) so that the back surface 36 faces the hybrid reinforcing bar 32 side. In the hybrid reinforcing bar 32 shown in Fig. 2(c), the bamboo rod 33 and the reinforcing bar 34 are tied or adhered in a state where the side surface 37 of the bamboo rod 33 is in contact with the reinforcing bar 34.

[0020] The manufacturing method of the concrete structure 1 of this embodiment will be described. The manufacturing method of the concrete structure 1 includes a preparation process, a steel bar arranging process, a framework process, and a placing process.

[0021] In the preparation process, the reinforcing bars 3 are prepared. In the preparation process, after cutting the bamboo along the fiber direction of the oar, the work of preparing the bamboo reinforcing bar 31 composed of the linear bamboo rod 33 formed by cutting is carried out, and after cutting the bamboo along the fiber direction of the oar, the bamboo rod 33 formed by cutting and the steel bar 34 subjected to bending are connected to form a U-shaped hybrid reinforcing bar 32.

[0022] As shown in FIG. 4(b), the bamboo rod 33 is formed into a belt shape having a surface (skin 35) composed of a curved surface (cylindrical surface) and a back surface 36 composed of a flat surface by shaving the protruding portions 38 of the left and right side surfaces 37, 37 and the back surface 36 of the cross-sectionally arc-shaped bamboo rod 33 formed by cutting the cylindrical oar 30 along the fiber direction.

[0023] <G In the bar assembling process, the reinforcing bars 3 are assembled. In the bar assembling process, the hybrid reinforcing bar 32 and the bamboo reinforcing bar 31 arranged in a direction intersecting with the hybrid reinforcing bar 32 are assembled in a cage shape. At the intersection of the reinforcing bars 3 (the intersection of the bamboo rods 33), the reinforcing bars 3 are connected by inserting the fixing tool 4 in a state where the back surfaces of both reinforcing bars 3, 3 are adhered and temporarily fixed with an adhesive (see FIG. 3(a)). When the fixing tool 4 is a bamboo screw, the reinforcing bars 3 are connected by screwing the fixing tool 4 into the intersection of the reinforcing bars 3. In addition, a pilot hole may be formed in each bamboo rod 33 at the intersection, and the reinforcing bars 3 may be connected by inserting a fixing tool such as a pin into the pilot hole.

[0024] In the formwork assembling process, a formwork surrounding the reinforcing bars 3 is assembled. The formwork is assembled at a distance from the reinforcing bars 3 so as to ensure a predetermined covering thickness from the surface of the concrete part 2. The distance between the formwork and the reinforcing bars is ensured, for example, by interposing a spacer. The shape of the spacer and the material constituting the spacer are not limited, but it is more desirable to use those formed of natural-derived materials. In the placing process, concrete is placed into the formwork 6 and cured until a predetermined strength is developed.

[0025] According to the concrete structure 1 of this embodiment, by using a hybrid reinforcing bar 32, which consists of a bent steel bar 34 with a bamboo rod 33 fixed to it, as the reinforcing bar 3 placed at the corner of the concrete structure, the effort required to manufacture the reinforcing bar can be reduced. In other words, since steel bars 34 are used in the parts where bending is required, the effort required to manufacture can be reduced compared to bending the bamboo rod 33 while applying heat such as steam.

[0026] Furthermore, since the reinforcing bars 3, which mainly consist of bamboo poles 33, are lightweight, it is possible to reduce the weight of the concrete structure 1, making it easier to handle on site. Furthermore, since bamboo rods 33, which are mainly natural materials, are used as reinforcing bars 3 for the concrete structure 1, the environmental impact can be reduced.

[0027] Embodiments of the present invention have been described above. However, the present invention is not limited to the embodiments described above, and each of the above-described components can be modified as appropriate without departing from the spirit of the present invention. For example, in the above embodiment, the case in which the concrete structure 1 is a U-shaped channel was described, but the use, shape, etc. of the concrete structure 1 are not limited. For example, hybrid reinforcing bars may be used for reinforcing bars of small-scale precast retaining walls, catch basins, and other precast secondary products. In this case, the hybrid reinforcing bars have a frame-like shape in plan view, formed by reinforcing bars (reinforcing bars that have been bent) placed at the corners of the surrounding wall and bamboo rods connected to the reinforcing bars placed at the corners.

[0028] In the above embodiment, the case in which the bamboo reinforcing bar 31 and the hybrid reinforcing bar 32 (bamboo rods 33) are connected by fasteners 4 was described, but the method of connecting the bamboo reinforcing bar 31 and the hybrid reinforcing bar 32 is not limited, and for example, if displacement is to be allowed, they may be tied together with binding wire 5 or the like. [Explanation of Symbols]

[0029] 1. Concrete structure 2. Concrete section 3. Reinforcement muscles 31 Bamboo reinforcement bars 32 Hybrid reinforcement muscles 33 Bamboo stick 34 Reinforcement bars 35 Skin 36 Back side 37 Side view 4. Fasteners 5 Binding wire

Claims

1. Concrete section, A concrete structure comprising a plurality of reinforcing bars embedded in the concrete portion, At least a portion of the multiple reinforcing bars comprises a bamboo rod, which is made by cutting bamboo along the direction of the fibers of the pole and then cutting it, and a bent steel bar. A concrete structure characterized in that the bamboo poles are fixed to both ends of the reinforcing bar, along the direction of extension of the reinforcing bar.

2. The concrete structure according to claim 1, characterized in that the reinforcing bars and the bamboo poles are bonded together.

3. The concrete structure according to claim 1, characterized in that the reinforcing bars and the bamboo poles are fixed together with binding wire.

4. The preparation process for preparing reinforcing bars, The process of assembling reinforcing bars, A method for manufacturing a concrete structure, comprising a pouring step of pouring concrete into a formwork, In the aforementioned preparation step, after cutting the bamboo along the direction of the fibers of the pole, a hybrid reinforcing bar is formed by connecting the bamboo rod, which has been cut, with a bent steel bar. A method for manufacturing a concrete structure, characterized in that, in the reinforcement assembly step, bamboo reinforcing bars made from bamboo rods, which are obtained by cutting bamboo along the fiber direction of the rod, are arranged in a direction intersecting the hybrid reinforcing bars and combined in a grid or cage shape.

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