Reinforcing structure

Abstract

To provide a reinforcing structure or the like capable of efficiently preventing cracking of a wooden beam.SOLUTION: A reinforcement structure 10 reinforces a wooden beam having a through-hole 25 penetrating a beam body 2 in a beam width direction. The reinforcing structure 10 includes a fiber-reinforced sheet 3 disposed so as to cover positions of four directions a1 to a4 inclined by 45 degrees with respect to a beam axis direction H from a center C of a through-hole 25 on both side surfaces 21 of the beam body 2 in the beam axis direction, and a fiber-reinforced sheet 4 disposed over the entire periphery of a hole wall of the through-hole 25. The fiber-reinforced sheet 3 has a portion folded into the through-hole 25, and the portion and the fiber-reinforced sheet 4 are arranged in an overlapping manner in the through-hole 25.SELECTED DRAWING: Figure 2

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 through holes in wooden beams is expected to reduce the strength of the beam. Therefore, Patent Document 1 discloses a reinforcing structure for wooden beams with through holes, in which fiber reinforcing sheets are provided on both sides of the through holes in the beam axial direction on the side surfaces of the wooden beam, thereby preventing the reduction in the strength of the wooden beam. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6482224 Summary of the Invention [Problem to be solved by the invention]

[0005] FIG. 11 is a schematic diagram of a wooden beam 100 having 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 becomes large 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 there is a high possibility that a crack (split) 102 in the beam axis direction will occur in the wooden beam 100 starting from this position ("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).

[0006] In this regard, the reinforcement structure described in Patent Document 1 involves providing fiber reinforcement sheets in the beam depth direction on both sides of the through hole in the beam axis direction, which is not necessarily an effective measure to prevent cracks such as those described above.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a reinforcement structure etc. that can efficiently prevent cracks in wooden beams. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention is a reinforcing structure for a wooden beam having a through hole that penetrates the beam body in the beam width direction, and is characterized in that it comprises: a first fiber reinforcing sheet arranged on both side surfaces of the beam body in the beam axis direction so as to cover four positions inclined at 45° from the center of the through hole to the beam axis direction; and a second fiber reinforcing sheet arranged around the entire circumference of the hole wall of the through hole, wherein the first fiber reinforcing sheet has a portion that is folded into the through hole, and this portion and the second fiber reinforcing sheet are arranged overlapping each other within the through hole.

[0009] In the present invention, a first fiber-reinforced sheet is folded from the side of the beam body into the through hole, and the first fiber-reinforced sheet is arranged on the side of the beam body so as to cover four positions inclined at 45° from the center of the through hole with respect to the beam axis direction. In contrast, a second fiber-reinforced sheet is arranged inside the through hole so as to cover the hole wall, and the folded portion of the first fiber-reinforced sheet and the second fiber-reinforced sheet overlap. This allows the first and second fiber-reinforced sheets to reinforce the areas that are likely to become crack initiation points, thereby efficiently preventing cracks from occurring and progressing.

[0010] The first fiber reinforcement sheet is, for example, strip-shaped, and an end portion in the longitudinal direction is disposed on a side surface of the beam body in the beam axis direction. This allows for reinforcement of necessary areas with a small area of ​​fiber reinforced sheet.

[0011] The first fiber-reinforced sheet may be rectangular, with corners folded into the through holes. This allows the reinforcement range of the side surface of the beam body to be expanded.

[0012] The first fiber-reinforced sheet may be disposed so as to surround the entire periphery of the through hole, with a central portion folded into the through hole. This allows the entire periphery of the through-hole on the side of the beam body to be reinforced. Also, since the side of the beam body can be reinforced with a single fiber-reinforced sheet, construction is easy.

[0013] It is desirable that the first fiber reinforcement sheets are provided separately on both side surfaces of the beam body in the beam axis direction. In this case, the installation of the fiber reinforcement sheet can be carried out by one worker on one side of the beam body, making construction easier.

[0014] It is also desirable that the first fiber reinforcement sheet is disposed on the side surface of the beam body in a groove provided on the side surface. This prevents the fiber reinforcement sheet, etc. from protruding from the side of the beam body, making it easier to apply a fire-retardant layer, etc. to the beam body. [Effects of the Invention]

[0015] According to the present invention, a reinforcement structure or the like can be provided that can efficiently prevent cracks in wooden beams. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 shows a wooden beam 1. [Figure 2] FIG. 2 is a perspective view showing a side surface 21 of the beam body 2. [Figure 3] FIG. 10 is a diagram showing fiber-reinforced sheets 3 and 4 integrated together. [Figure 4] FIG. [Figure 5] An example in which separate fiber reinforcement sheets 3 are arranged on both sides 21 of the beam body 2. [Figure 6]FIG. 3 is a diagram showing a rectangular fiber-reinforced sheet 3a. [Figure 7] An example in which the corners of the fiber-reinforced sheet 3a are formed as strip-shaped portions 32a. [Figure 8] An example in which the strip-shaped portions of the fiber reinforcement sheet 3a on both sides 21 of the beam body 2 are continuous. [Figure 9] 10 is an example of a fiber reinforcement sheet 3b surrounding the entire periphery of a through hole 25. [Figure 10] An example of a configuration in which the end of the fire-resistant coating 5 in the beam width direction is not exposed on the side of the beam body 2. [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) Figures 1(a) and (b) are diagrams showing a wooden beam 1 having a reinforcement structure 10 according to an embodiment of the present invention. Figure 1(a) is a diagram showing a side view of the wooden beam 1 in the beam axis direction, and Figure 1(b) is a diagram showing a cross section of the wooden beam 1 perpendicular to the beam axis direction. Figure 1(b) is a cross section taken along line AA in Figure 1(a). The beam axis direction corresponds to the left-right direction in Figure 1(a) and the normal direction to the paper surface in Figure 1(b).

[0019] The wooden beam 1 has a beam body 2, a fire-resistant coating 5, a fire-retardant layer 6, etc. The reinforcing structure 10 reinforces the beam body 2 of the wooden beam 1 with fiber reinforcing sheets 3, 4.

[0020] The beam body 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 body 2 that is perpendicular to the beam axis direction is rectangular, but this is not limited to this. The wooden material is laminated timber or the like with the fiber direction aligned with the beam axis direction, but this is not limited to this. For example, other wooden materials with the fiber direction aligned with 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-down direction in Figures 1(a) and (b).

[0021] The beam body 2 has a through hole 25. The through hole 25 is provided so as to penetrate the beam body 2 in the beam width direction. The beam width direction is a direction perpendicular to the beam axis direction and the beam depth direction, and corresponds to the normal direction to the paper surface of FIG. 1(a) and the left-right direction of FIG. 1(b). The through hole 25 is for passing equipment piping and the like, and in this embodiment is formed in the center of the wooden beam 1 in the beam depth direction, and has a circular cross section. However, the position and shape of the through hole 25 are not particularly limited.

[0022] The fire-resistant coating 5 is a tubular member provided inside the through-hole 25 and inside the opening 61 of the fire-retardant layer 6, which will be described later. The fire-resistant coating 5 is formed from, for example, mortar or a wood material impregnated with a fire-retardant agent, but is not limited to these.

[0023] The fire-retardant layer 6 is a plate-like member provided to cover the side surface 21 and bottom surface 23 of the beam body 2 in the beam axis direction. The fire-retardant layer 6 is a part for stopping the combustion of the wooden beam 1 in the event of a fire, etc., and is formed from wood material impregnated with a fire-retardant agent, but is not limited to this. The fire-retardant layer 6 is omitted from the top surface 22 of the beam body 2 because it comes into contact with a concrete slab (not shown), etc., but in some cases the fire-retardant layer 6 may be provided.

[0024] The fire-retardant layer 6 on the side surface 21 of the beam body 2 has an opening 61 at a position corresponding to the outer periphery of the fire-resistant coating 5. The fire-retardant layer 6 is continuous with the fire-resistant coating 5 at the inner periphery of the opening 61. It is also possible to provide a substitute fire layer or decorative material made of wood on the outside of the fire-retardant layer 6.

[0025] (2. Reinforcement structure 10) 2 is a perspective view showing the side surface 21 of the beam body 2 with the fire-retardant layer 6 omitted. In this embodiment, the area around the through hole 25 on the side surface 21 of the beam body 2 is reinforced using fiber reinforcement sheets 3 (3-1 to 3-4), and the wall of the through hole 25 in the beam body 2 is reinforced by a fiber reinforcement sheet 4. This prevents cracks originating from the through hole 25 in the beam axis direction (the fiber direction of the beam body 2).

[0026] The fiber reinforced sheet 3 (first fiber reinforced sheet) is a strip-shaped sheet that is mainly provided on the side surface 21 of the beam body 2, and the fiber reinforced sheet 4 (second fiber reinforced sheet) is a strip-shaped sheet that is provided on the hole wall of the through hole 25. An aramid fiber sheet with known structural performance is used as the fiber reinforced sheets 3 and 4. The width of the fiber reinforced sheet 3 is, for example, about 10 cm. The width of the fiber reinforced sheet 4 corresponds to the length of the through hole 25 in the beam width direction and is larger than that of the fiber reinforced sheet 3. The thickness of the fiber reinforced sheets 3 and 4 is, for example, 1 mm or less. However, the material and dimensions of the fiber reinforced sheets 3 and 4 are not limited to these. For example, a carbon fiber reinforced sheet can also be used as the fiber reinforced sheets 3 and 4.

[0027] The fiber-reinforced sheets 3-1 to 3-4 are arranged by folding them from the side surface 21 of the beam body 2 into the through-hole 25. The longitudinal ends of the fiber-reinforced sheets 3-1 to 3-4 are arranged radially outward from the through-hole 25 on the side surface 21 of the beam body 2. The ends are arranged so as to cover positions in four directions a1 to a4 that are inclined at 45° from the center C of the through-hole 25 with respect to the beam axis direction H. While FIG. 2 shows one longitudinal end of the fiber-reinforced sheets 3-1 to 3-4 arranged on one side surface 21 of the beam body 2, the other longitudinal end of the fiber-reinforced sheets 3-1 to 3-4 is also arranged on the opposite side surface 21 in the same arrangement as in FIG. 2.

[0028] By folding the fiber-reinforced sheets 3-1 to 3-4 at the opening edges of the through-holes 25, the intermediate portion in the longitudinal direction of the fiber-reinforced sheet 3-1 is provided inside the through-holes 25. The intermediate portion is overlapped on the inner surface of the fiber-reinforced sheet 4 inside the through-holes 25.

[0029] The fiber reinforced sheet 3 is adhered and fixed to the side surface 21 of the beam body 2 and the inner surface of the fiber reinforced sheet 4 with an adhesive. The fiber reinforced sheet 3 only needs to have the structurally necessary length, and the longitudinal ends do not need to reach the top surface 22 or the bottom surface 23 of the beam body 2.

[0030] The fiber reinforced sheet 4 is arranged so as to cover the inner surface of the hole wall of the through hole 25 around the entire periphery of the hole wall. The fiber reinforced sheet 4 is adhered and fixed to the inner surface of the hole wall with an adhesive (not shown). Both end portions 41 of the fiber reinforced sheet 4 are overlapped on the hole wall of the through hole 25. When viewed from the center C of the through hole 25, the position is either left or right in the beam axis direction H or above or below in the beam depth direction, and is in a position separate from the fiber reinforced sheet 3.

[0031] The adhesive used for the fiber-reinforced sheets 3, 4 is, for example, an epoxy resin-based adhesive, and does not particularly need to be used in combination with screws or nails, and the fiber-reinforced sheets 3, 4 can be fixed using only the adhesive.

[0032] In the reinforced structure 10, by overlapping the longitudinal middle portion of the fiber-reinforced sheet 3 on the inner surface of the fiber-reinforced sheet 4, the state in which the fiber-reinforced sheet 4 is fixed to the wall of the through hole 25 can be reinforced by the fiber-reinforced sheet 3. However, it is also possible to arrange the longitudinal middle portion of the fiber-reinforced sheet 3 on the wall of the through hole 25 and overlap the fiber-reinforced sheet 4 inside it. Furthermore, the fiber-reinforced sheets 3, 4 themselves may be configured by overlapping multiple layers of sheets as necessary. The fire-resistant coating 5 is provided inside the fiber-reinforced sheets 3, 4 within the through hole 25.

[0033] The wooden beam 1 is manufactured in a factory or the like by adhering fiber reinforcement sheets 3 and 4 to a beam body 2 having a through hole 25, and then attaching a fire-resistant coating 5 and a fire-retardant layer 6 to the beam body 2. The finished wooden beam 1 is then transported to the construction site and used. It is preferable to adhere the fiber reinforcement sheets 3 and 4 separately, but as shown in Figure 3, the fiber reinforcement sheets 3 and 4 can also be pre-assembled and then adhered to the beam body 2.

[0034] As described above, in the reinforcement structure 10 of this embodiment, the fiber-reinforced sheet 3 is folded from the side surface 21 of the beam body 2 into the through-hole 25. On the side surface 21 of the beam body 2, the fiber-reinforced sheet 3 is arranged to cover the four directions a1 to a4 inclined at 45° from the center C of the through-hole 25 relative to the beam axis direction H. In contrast, within the through-hole 25, the fiber-reinforced sheet 4 is arranged to cover the hole wall of the through-hole 25, and the folded portion of the fiber-reinforced sheet 3 overlaps the fiber-reinforced sheet 4. This allows the integrated fiber-reinforced sheets 3 and 4 to reinforce the areas that are prone to crack initiation, thereby efficiently preventing cracks from occurring and progressing. This allows the diameter of the through-hole 25 relative to the beam depth of the wooden beam 1 to be increased, lowering the hurdle for forming the through-hole 25 in the wooden beam 1. As a result, the flexibility of the arrangement of equipment piping and the like is improved, enabling the reduction of the building's floor height and the effective use of the space above the ceiling.

[0035] The fiber reinforcement sheet 3 is strip-shaped, and its longitudinal end is disposed on the side surface 21 of the beam body 2. This allows the fiber reinforcement sheet 3 with a small area to reinforce the necessary areas.

[0036] In this embodiment, the fiber reinforcement sheet 3 is provided continuously between both side surfaces 21 of the beam body 2, making it possible to reinforce both side surfaces 21 of the beam body 2 with a single fiber reinforcement sheet 3. The fire resistance of the wooden beam 1 is ensured by providing a fire-retardant layer 6 on the side surfaces 21 and bottom surface 23 of the beam body 2, and covering the outside of the fiber reinforcement sheet 3 with the fire-retardant layer 6 is also effective in terms of design.

[0037] However, the present invention is not limited to the above-described embodiments. For example, as shown in Figure 4, a groove 24 may be formed by cutting into the side surface 21 of the beam body 2, and a fiber-reinforced sheet 3 may be placed in the groove 24. The depth of the groove 24 is determined taking into consideration the thickness of the fiber-reinforced sheet 3 and adhesive 7. This prevents the fiber-reinforced sheet 3 and adhesive 7 from protruding from the side surface 21 of the beam body 2, making it easier to install the fire-retardant layer 6, etc. A similar groove can also be formed in the hole wall of the through-hole 25, in the area where the fiber-reinforced sheet 3 will be installed.

[0038] 5, which is a perspective view similar to that of FIG. 2, the fiber-reinforced sheet 3 may be discontinuous within the through-hole 25 of the beam body 2, with separate fiber-reinforced sheets 3 being arranged on both side surfaces 21 of the beam body 2. The length of the fiber-reinforced sheet 3 within the through-hole 25 is determined so as to ensure a sufficient adhesive margin between the fiber-reinforced sheet 4 and the like.

[0039] When the fiber reinforcement sheet 3 is continuous between both sides 21 of the beam body 2 as in Figure 2, the work of attaching the fiber reinforcement sheet 3 must be carried out by two workers positioned on each side 21 of the beam body 2 working together.However, in the case of Figure 5, the work of attaching the fiber reinforcement sheet 3 to each side 21 of the beam body 2 can be carried out alone by one worker positioned on each side 21 of the beam body 2, making construction easier.

[0040] 6(a), which is a perspective view similar to FIG. 2, the fiber-reinforced sheet 3a may be rectangular, with its corners folded at the opening edges of the through-holes 25 and then folded into the through-holes 25. By using a rectangular fiber-reinforced sheet 3a, it is possible to expand the reinforcement range of the side surfaces 21 of the beam body 2. Furthermore, the fiber-reinforced sheet 3a is usually pre-cut from a roll product, but by making the fiber-reinforced sheet 3a rectangular, the effort required for pre-cutting can be reduced.

[0041] As shown in Figure 6(b), at the corners of the fiber-reinforced sheet 3a, radial cuts 31 are provided starting from the corners of the fiber-reinforced sheet 3a. The tips of the cuts 31 are located on an arc r whose center is the corner of the fiber-reinforced sheet 3a. The shape (curvature) of the arc r corresponds to the opening edge of the through-hole 25.

[0042] By dividing and narrowing the corners of fiber-reinforced sheet 3a in this way, when the corners of fiber-reinforced sheet 3a are folded into through-hole 25, each divided portion 32 easily fits against the wall of through-hole 25, facilitating application and other operations. For the above-mentioned purpose, the upper limit of length L along arc r of each divided portion 32 at the position of arc r should preferably be approximately 10 cm. Furthermore, by folding divided portions 32 narrowed by the above-mentioned incisions 31 into through-hole 25, fiber-reinforced sheet 3a can be used without waste.

[0043] 7(a) and 7(b), which are similar to FIGS. 6(a) and 6(b), the corners of the fiber-reinforced sheet 3a may be formed as strip-shaped portions 32a extending from the center of the arc r to the corners of the fiber-reinforced sheet 3a, and portions outside the arc r may be omitted in other locations. Folding only the strip-shaped portions 32a into the through-holes 25 facilitates the folding of the fiber-reinforced sheet 3a. In this case, the length L of the strip-shaped portions 32a along the arc r at the position of the arc r should preferably be limited to approximately 10 cm.

[0044] Furthermore, in the example of Figure 7(a), the fiber reinforcement sheet 3a on both side surfaces 21 of the beam body 2 is discontinuous, but as shown in Figure 8, the fiber reinforcement sheet 3a on both side surfaces 21 of the beam body 2 may be made continuous by the above-mentioned strip-shaped portion 32a.

[0045] 9(a) and 9(b), which are similar to FIGS. 6(a) and 6(b), a fiber-reinforced sheet 3b may be arranged on the side surface 21 of the beam body 2 so as to surround the entire periphery of the through-hole 25 in a rectangular shape. As shown in FIG. 9(b), the fiber-reinforced sheet 3b has radial cuts 33 formed from its center to a circumference R surrounding the center. The shape of the circumference R corresponds to the opening edge of the through-hole 25.

[0046] The fiber-reinforced sheet 3b can be arranged by folding each divided portion 34, separated by incisions 33, into the through-hole 25. In this case, the entire periphery of the through-hole 25 on the side surface 21 of the beam body 2 can be reinforced. Furthermore, since the side surface 21 of the beam body 2 can be reinforced with a single fiber-reinforced sheet 3b, installation is easy. Note that, in this case, the length L along the circumference R of the divided portion 34 at the position of the circumference R should preferably be limited to approximately 10 cm. In the example of FIG. 9, the fiber-reinforced sheet 3b is arranged so as to surround the through-hole 25 in a rectangular shape, but it may also be arranged so as to surround it in a circular shape.

[0047] In addition, in this embodiment, the connection between the fire-resistant coating 5 and the fire-retardant layer 6 is such that the fire-resistant coating 5 is in contact with the beam, and the end of the fire-resistant coating 5 in the beam width direction is exposed on the side of the beam body 2. However, as shown in Figure 10, which is a cross section similar to Figure 1(b), the fire-retardant layer 6 may be in contact with the beam, and the end of the fire-resistant coating 5 in the beam width direction may not be exposed on the side of the beam body 2.

[0048] 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]

[0049] 1, 100: Wooden beam 2: Beam body 3, 3-1 to 3-4, 3a, 3b: Fiber reinforced sheet 4: Fiber reinforced sheet 5: Fireproof coating 6: Fire-retardant layer 10: Reinforcement structure 21: Side 24: Groove 25, 101: Through holes

Claims

1. A reinforcement structure for a wooden beam having a through hole penetrating the beam body in the beam width direction, A first fiber reinforcement sheet is arranged on both side surfaces of the beam body in the beam axis direction so as to cover four positions inclined at 45° from the center of the through hole with respect to the beam axis direction; a second fiber reinforcement sheet arranged around the entire periphery of the hole wall of the through hole; Equipped with A reinforced structure characterized in that the first fiber reinforced sheet has a portion that is folded into the through hole, and that portion and the second fiber reinforced sheet are arranged overlapping each other within the through hole.

2. 2. The reinforced structure according to claim 1, wherein the first fiber reinforcement sheet is strip-shaped, and a longitudinal end portion is disposed on a side surface of the beam body in the beam axis direction.

3. 2. The reinforced structure according to claim 1, wherein the first fiber reinforced sheet is rectangular, and corners of the first fiber reinforced sheet are folded into the through holes.

4. 2. The reinforced structure according to claim 1, wherein the first fiber reinforcement sheet is disposed so as to surround the entire periphery of the through hole, and a central portion of the first fiber reinforcement sheet is folded into the through hole.

5. 2. The reinforced structure according to claim 1, wherein the first fiber reinforcement sheet is provided so as to be continuous between both side surfaces of the beam body in the beam axis direction.

6. 2. The reinforced structure according to claim 1, wherein the first fiber reinforcement sheet is provided separately on both side surfaces of the beam body in the beam axis direction.

7. The reinforcement structure according to claim 1, wherein the first fiber reinforcement sheet is disposed in a groove formed on the side surface of the beam body.

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