Reinforcing structure

Abstract

To provide a reinforcing structure or the like capable of surely reinforcing a through-hole, in a woody beam for superposing a beam material in the beam width direction.SOLUTION: The wooden beam is formed by stacking a plurality of beam materials 2 in the beam width direction so that facing surfaces 22 which are side surfaces in the beam axis direction of the beam materials 2 face each other. The beam material 2 has a through-hole 21 penetrating in the beam width direction. In the reinforcing structure of the wooden beam, a fiber-reinforced sheet 3 is provided around a through-hole 21 of an opposite surface 22 of a beam material 2 and on a hole wall of the through-hole 21. The fiber-reinforced sheet 3 is disposed so as to cover the positions of four directions a1 to a4 inclined by 45 degrees with respect to the beam axial direction H from the center C of the through-hole 21 on the facing surface 22 of the beam member 2.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a reinforcement structure for a wooden beam. [Background technology]

[0002] In recent years, the use of wooden materials as beams in buildings has been increasing. Drilling through-holes in these wooden beams to run plumbing and other equipment has the advantage of making effective use of the space above the ceiling and reducing the height of floors.

[0003] However, drilling a through hole in a wooden beam is expected to reduce its strength. For example, Figure 11 shows a schematic diagram of a wooden beam 100 with a through hole 101. It is known that stress generated around the through hole 101 of the wooden beam 100 due to a vertical load or the like increases at a position a on the side surface of the wooden beam 100 in the beam axis direction, which is inclined at approximately 45° from the center C of the through hole 101 to the beam axis direction H, and that this position is likely to cause a crack (split) 102 in the beam axis direction of the wooden beam 100 ("Study on the Strength of Glulam Beams with Circular Holes," Okamoto et al., Transactions on Structural Engineering, Architectural Institute of Japan, Vol. 85, No. 775, pp. 1199-1208, September 2020).

[0004] In response to this, Patent Document 1 discloses a reinforcing structure for a wooden beam having a through hole, in which a fiber reinforcing sheet is provided on the side of the beam core of the wooden beam, thereby suppressing a decrease in the strength of the wooden beam. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6482224 Summary of the Invention [Problem to be solved by the invention]

[0006] Some wooden beams are made by stacking beam materials in the beam width direction. Even in such cases, there is a need for a reinforcing structure for the through holes that can reliably reinforce the through holes.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a reinforcement structure etc. that can reliably reinforce through holes in wooden beams in which beam materials are stacked in the beam width direction. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention is a reinforcing structure for a wooden beam, wherein the wooden beam is made by stacking multiple beam materials in the beam width direction so that opposing surfaces, which are the side surfaces of the beam materials in the beam axis direction, face each other, and the beam materials have through holes that penetrate in the beam width direction, and a fiber reinforcing sheet is provided around the through holes on the opposing surfaces of the beam materials and on the hole walls of the through holes.

[0009] In this invention, a wooden beam is constructed from multiple beams, and a fiber-reinforced sheet is provided around the through-holes on the opposing surfaces of the beams and on the walls of the through-holes. This ensures that the through-holes in a wooden beam, in which beams are stacked in the beam width direction, are reinforced, and the fiber-reinforced sheet can suppress cracks that propagate from the through-holes. Furthermore, the fiber-reinforced sheet on the opposing surfaces of the beams is sandwiched between the beams and positioned inside the wooden beam, which is also preferable in terms of durability, etc.

[0010] It is desirable that the fiber reinforcement sheet be provided only on the opposing surfaces of the beam material and the hole wall of the through hole. This prevents the fiber-reinforced sheet from being exposed to the outside of the wooden beam, which is preferable in terms of the design of the wooden beam.

[0011] The fiber reinforcement sheets are preferably arranged on the opposing surfaces of the beam material so as to cover four positions inclined at 45° from the center of the through hole to the beam axis. This makes it possible to more reliably prevent the occurrence and progression of cracks in beam materials having through holes.

[0012] It is desirable that the fiber reinforcement sheet be provided so as to be continuous across the opposing surfaces of the beam members and the wall of the through-hole. It is also desirable that the opening edge of the through-hole be chamfered. If the fiber-reinforced sheet is continuous between the opposing surface of the beam and the wall of the through-hole, the installation of the fiber-reinforced sheet can be easily performed. Furthermore, the fiber-reinforced sheet on the opposing surface of the beam and the fiber-reinforced sheet on the wall of the through-hole can resist stress around the through-hole as a whole. Furthermore, by chamfering the opening edge of the through-hole, the fiber-reinforced sheet can be prevented from bending at a right angle at the opening edge, thereby suppressing damage to the fiber-reinforced sheet.

[0013] It is also desirable that the fiber reinforcement sheet be disposed on the opposing surface of the beam member in a groove provided on the opposing surface of the beam member. This prevents the fiber reinforcement sheet or the like from floating up from the opposing surfaces of the beams, and allows the beams to be aligned without gaps.

[0014] It is also desirable that the fiber reinforcement sheets on the opposing surfaces of the plurality of beam members are arranged so that they partially overlap when viewed from the extension direction of the through holes. This allows a wide area to be reinforced while reducing the amount of fiber reinforcement sheet used. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a reinforcement structure etc. that can reliably reinforce through holes in a wooden beam in which beam materials are stacked in the beam width direction. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 shows a wooden beam 1 having a reinforcing structure 10. [Figure 2] FIG. 2 is a diagram showing a cross section of a wooden beam 1. [Figure 3] FIG. 2 is an exploded perspective view of a beam material 2 that constitutes the wooden beam 1. [Figure 4] Another example of the arrangement of the fiber reinforcement sheet 3. [Figure 5] Another example of the arrangement of the fiber reinforcement sheet 3. [Figure 6] FIG. 2 shows grooves 211 and 221. [Figure 7] 10 shows an example of chamfering the opening edge of a through hole 21. [Figure 8] FIG. 1 shows a wooden beam 1a having a reinforcing structure 10a. [Figure 9] An example in which the fiber reinforced sheet is divided into a sheet 31 on the opposing surface 22 and a sheet 32 ​​on the hole wall of the through hole 21. [Figure 10] 10 shows an example in which the cross section of the through hole 21 is rectangular. [Figure 11] 1 is a diagram showing an outline of a wooden beam 100. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0018] (1. Wood beam 1) FIG. 1 is a diagram showing a wooden beam 1 having a reinforcing structure 10 according to an embodiment of the present invention, showing a side view of the wooden beam 1 in the beam axis direction. The beam axis direction corresponds to the left-right direction in FIG. 1. As shown in FIG. 1, the wooden beam 1 has a beam material 2, a fiber reinforcing sheet 3, etc. The reinforcing structure 10 reinforces the beam material 2 of the wooden beam 1 with the fiber reinforcing sheet 3.

[0019] The beam 2 is a load-bearing part of the wooden beam 1 that mainly bears the load, and is formed into a beam shape from wooden material. The cross section of the beam 2 perpendicular to the beam axis direction is, for example, rectangular. The wooden material is, for example, laminated timber with the fiber direction in the beam axis direction, but is not limited to this. For example, other wooden materials with the fiber direction in the beam axis direction or beam depth direction, such as CLT (Cross Laminated Timber), may also be used. The beam depth direction corresponds to the up and down direction in Figure 1.

[0020] Figure 2 shows a cross section of the wooden beam 1 taken along line AA in Figure 1. As shown in Figure 2, the wooden beam 1 is formed by stacking multiple beam materials 2 in the beam width direction so that opposing surfaces 22, which are the side surfaces in the beam axis direction, face each other. The beam width direction is a direction perpendicular to the beam axis direction and the beam depth direction, and corresponds to the left-right direction in Figure 2.

[0021] The beam material 2 has a through hole 21. The through hole 21 is provided so as to penetrate the beam material 2 in the beam width direction. The through hole 21 is for passing equipment piping and the like. As shown in FIG. 1, in this embodiment, the through hole 21 is formed in the center of the beam material 2 in the beam depth direction, and its cross section is circular. However, the position and shape of the through hole 21 are not particularly limited.

[0022] The fiber reinforced sheet 3 is a strip-shaped sheet provided on the opposing surface 22 of the beam 2 and on the wall of the through hole 21. The fiber reinforced sheet 3 reinforces the beam 2 and suppresses the occurrence and progression of the cracks described above. An aramid fiber sheet with known structural performance is used as the fiber reinforced sheet 3. The fiber reinforced sheet 3 is narrow, for example, about 10 cm wide, and has a thickness of, for example, 1 mm or less. However, the material and dimensions of the fiber reinforced sheet 3 are not limited to these. For example, a carbon fiber reinforced sheet can also be used as the fiber reinforced sheet 3.

[0023] In this embodiment, the fiber reinforced sheet 3 is provided so as to be continuous across the opposing surface 22 of the beam 2 and the hole wall of the through hole 21. The fiber reinforced sheet 3 is adhered and fixed to the opposing surface 22 of the beam 2 and the hole wall of the through hole 21 by an adhesive (not shown). The adhesive may be an epoxy resin-based adhesive, but is not limited to this.

[0024] The positions of the through holes 21 and the fiber reinforcement sheets 3 on the opposing surfaces 22 of the beams 2 correspond among the multiple beams 2 that make up the wooden beam 1. The fiber reinforcement sheets 3 on the opposing surfaces 22 of these beams 2 are fixed together with an adhesive or the like (not shown). Alternatively, screws (not shown) may be driven into the wooden beam 1 in the beam width direction so as to penetrate the fiber reinforcement sheets 3 on the opposing surfaces 22 of both beams 2.

[0025] (2. Reinforcement structure 10 using fiber reinforcement sheet 3) 3 is an exploded perspective view of a beam material 2 that constitutes a wooden beam 1. In this embodiment, four fiber-reinforcement sheets 3 (3-1 to 3-4) are used to reinforce the area around the through-hole 21 of the beam material 2, thereby preventing cracks originating from the through-hole 21 in the beam axis direction (the fiber direction of the beam material 2).

[0026] One end of the fiber-reinforced sheets 3-1 to 3-4 in the longitudinal direction is arranged radially outward from the through-hole 21 on the opposing surface 22 of the beam material 2. The end is arranged so as to cover positions in four directions a1 to a4 inclined at 45 degrees from the center C of the through-hole 21 with respect to the beam axis direction H.

[0027] The other longitudinal end portions of the fiber-reinforced sheets 3-1 to 3-4 are folded back at the opening edge of the through hole 21 and folded into the through hole 21, and are provided on the hole wall of the through hole 21. The end portions reach the middle portion of the through hole 21 in the extension direction. However, the end portions may be arranged within the through hole 21 so as to reach just before the side surface 23 opposite the opposing surface 22 of the beam material 2, or so as to reach the side surface 23.

[0028] The length L and width W of the fiber reinforcement sheets 3-1 to 3-4 on the opposing surface 22 of the beam 2 are determined so that they can cover with a margin the area where stress is high at the opening edge of the through hole 21, as determined in advance by structural calculations. The width W of the fiber reinforcement sheets 3-1 to 3-4 is also set to cover with a margin the area that is expected to be the starting point of a crack, even on the wall of the through hole 21. This allows the fiber reinforcement sheets 3-1 to 3-4 to cover the width of a crack that is expected to occur in the beam 2 from the starting point on the wall of the through hole 21, preventing the occurrence of cracks.

[0029] The through holes 21 are formed in the beam 2 at a factory or the like, and the fiber reinforcing sheet 3 is also provided in the beam 2 at a factory or the like. The beam 2 thus produced is carried to a construction site, and a pair of beams 2 are stacked to form the wooden beam 1. Alternatively, the wooden beam 1 may be produced by stacking a pair of beams 2 at a factory or the like, and the finished wooden beam 1 may be carried to the construction site for use.

[0030] As described above, in this embodiment, a wooden beam 1 is constructed using multiple beams 2, and fiber reinforcement sheets 3 are provided around the through holes 21 on the opposing surfaces 22 of the beams 2 and on the holes' walls. This ensures that the through holes 21 in the wooden beam 1, in which the beams 2 are stacked in the beam width direction, are reinforced, and cracks propagating from the through holes 21 can be suppressed by the fiber reinforcement sheets 3. By reinforcing the through holes 21 in this way, the diameter of the through holes 21 relative to the beam depth can be increased, and the hurdle for forming the through holes 21 is lowered. As a result, the degree of freedom in arranging equipment piping and the like is improved, which enables the reduction of the building's floor height and the effective use of the space above the ceiling.

[0031] In addition, the fiber reinforcement sheet 3 on the opposing surface 22 of the beam material 2 is sandwiched between the beam materials 2 and positioned inside the wooden beam 1, which is also preferable in terms of durability, etc. Furthermore, the fiber reinforcement sheet 3 is only provided on the opposing surface 22 of the beam material 2 and the hole wall of the through hole 21, and is not provided on the side surface 23 opposite the opposing surface 22 of the beam material 2, which prevents the fiber reinforcement sheet 3 from being exposed to the outside of the wooden beam 1, which is also preferable in terms of the design of the wooden beam 1.

[0032] In addition, on the opposing surface 22 of the beam material 2, the fiber reinforcement sheet 3 is arranged to cover the positions in four directions a1 to a4 inclined at 45° from the center C of the through hole 21 to the beam axis direction H, thereby more reliably preventing the occurrence and progression of cracks in the beam material 2 having the through hole 21.

[0033] Furthermore, in this embodiment, the fiber-reinforced sheet 3 is provided so as to be continuous across the opposing surface 22 of the beam 2 and the hole wall of the through hole 21, which simplifies the installation of the fiber-reinforced sheet 3 compared to when the fiber-reinforced sheet 3 is separately disposed on the opposing surface 22 of the beam 2 and the hole wall of the through hole 21. Furthermore, the fiber-reinforced sheet 3 on the opposing surface 22 of the beam 2 and the fiber-reinforced sheet 3 on the hole wall of the through hole 21 can integrally resist stress around the through hole 21.

[0034] However, the present invention is not limited to the above-described embodiment. For example, in this embodiment, two beams 2 are stacked to form the wooden beam 1, but three or more beams 2 may be stacked as described above to form a wooden beam. In this case, too, the fiber-reinforced sheet 3 is provided on the opposing surfaces 22 of the adjacent beams 2 and on the hole walls of the through holes 21.

[0035] The fiber reinforcement sheet 3 may be arranged continuously from inside the through-hole 21 of the beam 2 to the side surface 23 opposite the opposing surface 22 of the beam 2, in the same arrangement on the side surface 23 as on the opposing surface 22. This improves the reinforcing effect of the beam 2.

[0036] Furthermore, the fiber-reinforced sheet 3 only needs to be provided around the through-hole 21 on the opposing surface 22 of the beam 2 and on the hole wall of the through-hole 21, and its specific arrangement is not limited to the example shown in Fig. 3. Figs. 4 and 5 show other examples of the arrangement of the fiber-reinforced sheet 3 in perspective views similar to Fig. 3.

[0037] For example, in the example of Figures 4(a) and (b), two fiber reinforced sheets 3 that become wider as they move away from the through hole 21 are arranged on the opposing surface 22 of the beam material 2, one on each side of the beam axis direction of the through hole 21 and one above and one below. These fiber reinforced sheets 3 are folded back at the opening edges of the through hole 21 and folded into the hole wall of the through hole 21. In the example of Figure 4(c), on the opposing surface 22 of the beam material 2, arc-shaped fiber reinforced sheets 3 that follow the opening edges of the through hole 21 are provided at the upper left, upper right, lower left, and lower right of the through hole 21. These fiber reinforced sheets 3 are also folded back at the opening edges of the through hole 21 and folded into the hole wall of the through hole 21.

[0038] In the example of Fig. 5(a), a fiber-reinforced sheet 3 is provided on the opposing surface 22 of the beam 2, surrounding the periphery of the through hole 21 in a rectangular shape. As above, the fiber-reinforced sheet 3 is folded back at the opening edge of the through hole 21 and folded into the wall of the through hole 21. Fig. 5(b) shows an example in which the fiber-reinforced sheet 3 of Fig. 5(a) is divided into two parts, top and bottom, and Fig. 5(c) shows an example in which the fiber-reinforced sheet 3 of Fig. 5(a) is divided into four parts, top and bottom, left and right.

[0039] The example in Figure 5(a) is easy to install because only one fiber-reinforced sheet 3 is required, while the examples in Figures 4(a), (b), and 5(b) are next easiest to install because only two fiber-reinforced sheets 3 are required. In addition, in the examples in Figures 4(b), 5(a), and (b), the fiber-reinforced sheet 3 extends in the beam axis direction above and below the through-hole 21, improving the load transfer performance in the beam axis direction. In addition, in the examples in Figures 4(c) and 5(c), the fiber-reinforced sheet 3 around the through-hole 21 is divided into four pieces, which allows for a wide coverage of the periphery of the through-hole 21 while minimizing the amount of fiber-reinforced sheet 3 used.

[0040] 6, which is a cross section similar to that of FIG. 2, grooves 211 and 221 may be formed by carving holes in the wall of the through-hole 21 of the beam 2 and the opposing surface 22, respectively, and the fiber-reinforced sheet 3 may be placed in the grooves 211 and 221. The depth of the grooves 211 and 221 is determined taking into consideration the thickness of the fiber-reinforced sheet 3 and the adhesive material. This prevents the fiber-reinforced sheet 3 and the adhesive material from protruding from the wall of the through-hole 21 of the beam 2 and the opposing surface 22, and allows two beams 2 to be stacked without gaps, making the construction of the wooden beam 1 easier. However, the carving holes require more effort to manufacture the beam 2.

[0041] Furthermore, as shown in Fig. 7, which is a cross section similar to Fig. 2, at the opening edge of through hole 21 in beam 2, a part or the entire circumference corresponding to the folded portion of fiber-reinforced sheet 3 may be chamfered to form an inclined surface 24 inclined relative to the opposing surface 22 and the wall of through hole 21. This makes it possible to prevent damage to fiber-reinforced sheet 3 caused by bending at a right angle at the opening edge of through hole 21. The inclined surface 24 can be very small without causing any problems.

[0042] In this embodiment, the fiber-reinforced sheets 3 are arranged at corresponding positions on the opposing surfaces 22 of the beams 2 that make up the wooden beam 1, but this is not limitative. For example, as shown in the reinforcing structure 10a of the wooden beam 1a in Fig. 8, the fiber-reinforced sheet 3a of one beam 2 and the fiber-reinforced sheet 3b of the other beam 2 may be arranged at different positions or in different orientations.

[0043] However, these fiber-reinforced sheets 3 are arranged so that they partially overlap when viewed from the extension direction of the through-hole 21 (corresponding to the direction normal to the paper surface in FIG. 8). This enables reinforcement over a wide area without increasing the amount of fiber-reinforced sheets 3 used. Both fiber-reinforced sheets 3a and 3b are arranged so as to cover positions in four directions a1 to a4 (see FIG. 3) inclined at 45° from the center C of the through-hole 21 with respect to the beam axis direction H.

[0044] Furthermore, as shown in the exploded perspective view of Figure 9, the fiber reinforcement sheet of the beam material 2 may be divided into a sheet 31 on the opposing surface 22 and a sheet 32 ​​on the wall of the through hole 21. Only one sheet of the former sheet 31 is provided between the beam materials 2. In this case, there is no need to fold back the fiber reinforcement sheet at the opening edge of the through hole 21. Also, since only one fiber reinforcement sheet is provided between the beam materials 2, the amount of fiber reinforcement sheet used can be reduced.

[0045] In the example of Figure 9, the sheet 31 is rectangular with a hole in the center and is arranged so as to surround the through-hole 21 of both beam members 2 in a rectangular shape. The sheet 32 ​​is a strip-shaped member arranged around the entire wall of the through-hole 21. Note that the sheet 32 ​​may be divided into multiple sheets arranged in the circumferential direction of the wall of the through-hole 21, but even in this case, it is necessary to cover with a margin the range that is expected to be the starting point of a crack. For example, the sheet 32 ​​is arranged so as to cover positions in four directions a1 to a4 (see Figure 3) inclined at 45° from the center C of the through-hole 21 to the beam axis direction H.

[0046] In addition, the form in which the fiber-reinforced sheet is divided into sheet 31 on the opposing surface 22 of the beam material 2 and sheet 32 ​​on the hole wall of the through hole 21 and installed can also be applied to other arrangement examples of the fiber-reinforced sheet 3, such as Figures 3 to 5.

[0047] Furthermore, although the cross section of the through hole 21 is circular in this embodiment, the shape of the through hole 21 is not limited to this. For example, as shown in FIG. 10, which is a perspective view similar to FIG. 3, the cross section of the through hole 21 in the beam material 2 may be rectangular. In this example, the fiber reinforced sheets 3 (3-1, 3-2) are rectangular on the opposing surfaces 22 of the beam material 2 and are arranged on both the left and right sides of the through hole 21 in the beam axis direction. These fiber reinforced sheets 3 are folded back at the opening edges of the through hole 21 and folded into the through hole 21. Because the cross section of the through hole 21 is rectangular, the fold lines of the fiber reinforced sheets 3 are straight. Therefore, the fiber reinforced sheets 3 can be easily folded back, making installation easier.

[0048] The shape and size of the fiber-reinforced sheet 3 on the facing surface 22 are also determined so that it can comfortably cover the area where stress is high at the opening edge of the through hole 21, which was determined in advance by structural calculations. In this example, the fiber-reinforced sheet 3 (3-1, 3-2) is arranged on the facing surface 22 of the beam 2 so as to cover positions in four directions b1 to b4 that extend from the center C of the through hole 21 to the four corners of the cross section of the through hole 21. Note that in the example of Figure 10, as in the example of Figure 9, it is possible to install the fiber-reinforced sheet 3 separately on the facing surface 22 of the beam 2 and on the hole wall of the through hole 21.

[0049] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the technical ideas disclosed in this application, and it is understood that these modifications and alterations also fall within the technical scope of the present invention. [Explanation of symbols]

[0050] 1, 1a, 100: Wooden beam 2: Beam material 3, 3-1 to 3-4, 3a, 3b: Fiber reinforced sheet 10, 10a: Reinforcement structure 21, 101: Through holes 22: Opposite surface 23: Side 24: Inclined surface 211, 221: Groove

Claims

1. A reinforcement structure for wooden beams, The wooden beam is formed by stacking a plurality of beam materials in the beam width direction so that opposing surfaces, which are side surfaces in the beam axis direction of the beam materials, face each other, The beam material has a through hole penetrating in the beam width direction, A reinforced structure characterized in that a fiber reinforcement sheet is provided around the through hole on the opposing surface of the beam material and on the hole wall of the through hole.

2. 2. The reinforced structure according to claim 1, wherein the fiber reinforcement sheet is provided only around the through-hole on the opposing surface of the beam and on the wall of the through-hole.

3. The fiber reinforced sheet is provided on the opposing surface of the beam material.

2. The reinforcement structure according to claim 1, wherein the through-holes are arranged to cover four positions inclined at 45 degrees from the center of the through-hole with respect to the beam axis.

4. 2. The reinforced structure according to claim 1, wherein the fiber reinforcement sheet is provided so as to be continuous across the opposing surfaces of the beam material and the wall of the through hole.

5. 5. The reinforcement structure according to claim 4, wherein the opening edge of the through hole is chamfered.

6. 2. The reinforced structure according to claim 1, wherein the fiber reinforcement sheet is disposed in a groove formed on the opposing surface of the beam material.

7. 2. The reinforcement structure according to claim 1, wherein the fiber reinforcement sheets on the opposing surfaces of the beam members are arranged so as to partially overlap when viewed from the extension direction of the through holes.

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