Reinforced wood

Abstract

To improve the strength of a wood material by using a reinforcing material without impairing the beauty of the wood material, and to surely improve the strength by increasing the joining strength between the wood material and the reinforcing material.SOLUTION: Provided is a reinforced wood 1 made of a wood material 2 made of a log with a slit 3 cut along the axial direction, and an FRP reinforcing material 4 fixed with an adhesive into the slit 3. A fiber-reinforced plastic made of basalt fiber is used as the FRP reinforcing material 4. One or more strips of the FRP reinforcing material 4 are provided in a portion of the wood material 2 where a tensile force acts. The FRP reinforcing materials 4 are each provided in a cross direction in a cross section perpendicular to the axial direction of the wood material 2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to reinforced timber made of logs reinforced with FRP reinforcing materials. [Background technology]

[0002] In recent years, the use of wood has been reconsidered in order to conserve forests from the perspective of preventing global warming and landslides. Applications of wood in the civil engineering field include cross members for retaining earth, wooden piles driven into steep cut slopes for forest road construction to prevent the slopes from collapsing and to stabilize the slopes by easing the gradient, and logs driven into the ground for ground improvement and as a countermeasure against liquefaction of soft ground. The use of wood also has a long-term carbon storage effect (carbon stock effect) by continuing to use wood for a long period of time, which absorbs and fixes carbon dioxide during the growth process.

[0003] However, when wood is used for the above-mentioned cross members, wooden stakes, logs, etc., it has a drawback in that it has low strength characteristics. For this reason, reinforced wood, which is wood reinforced with a reinforcing material, has been developed. For example, Patent Document 1 listed below discloses a reinforced wood structure having at least a portion of a reinforcing wood as a supporting material, the portion being made of a fiber-reinforced plastic plate fixed in the longitudinal direction of the surface of the wood, and at least a portion of the reinforcing wood has a fiber-reinforced plastic plate fixed to both a portion where a tensile force acts and a portion where a compressive force acts when a bending load acts on the structure. Patent Document 2 listed below discloses a bending reinforcement structure for a wooden component having an opening, the opening of the wooden component being positioned at a position offset toward the edge from the center of the height of the wooden component, and a reinforcing material being positioned on the edge face on the opening side. Patent Document 3 listed below discloses a reinforced wood structure comprising wood, a reinforcing sheet formed into a cloth or mesh-like shape from reinforcing fibers, and a reinforcing solution, the reinforcing sheet being placed on the surface of the wood, and the wood and the reinforcing sheet being integrated by the reinforcing solution. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-328684 A [Patent Document 2] JP 2009-121030 A [Patent Document 3] JP 2003-48204 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the reinforced wood materials described in the above Patent Documents 1 to 3, the reinforcing material is disposed on the surface of the wood material, and therefore there is a problem that the reinforcing material mars the external appearance of the wood material, making it look unsightly.

[0006] Furthermore, in the reinforced wood described in Patent Documents 1 to 3, a reinforcing material formed in a plate, cloth or mesh shape is placed on the surface of the wood, and is joined to the wood on only one side of the reinforcing material. This means that the bonding strength between the wood and the reinforcing material is low, and there is a risk that the effect of the reinforcing material in improving the strength of the wood will be reduced.

[0007] Therefore, the main object of the present invention is to provide reinforced wood that improves strength by using reinforcing materials without compromising the aesthetic appearance of the wood, and that can reliably improve strength by increasing the bonding strength between the wood and the reinforcing materials. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention as claimed in claim 1 provides reinforced wood, characterized in that it is made of log material, has a groove cut along the axial direction, and an FRP reinforcing material fixed into the groove with an adhesive.

[0009] In the invention described in claim 1, a groove is formed along the axial direction on the surface of a wooden piece made of a log, an FRP reinforcing material is inserted into the groove, and the FRP reinforcing material is fixed into the groove with adhesive to form a reinforced wooden piece. Since the FRP reinforcing material is arranged in the groove, the reinforcing material is less noticeable in appearance than in conventional wooden pieces in which the reinforcing material is arranged on the surface of the wooden piece, and the strength of the reinforcing material can be improved without impairing the aesthetic appearance of the wooden piece. In addition, since the FRP reinforcing material is fixed with adhesive while inserted into the groove, the surface of the FRP reinforcing material facing the inner surface of the groove is fixed to the wooden piece, increasing the joint strength between the wooden piece and the FRP reinforcing material, and the FRP reinforcing material can be reliably reinforced by the wooden piece.

[0010] According to a second aspect of the present invention, there is provided a reinforced wood material as described in claim 2, in which basalt fiber is used as the reinforcing fiber of the FRP reinforcing material.

[0011] In the invention described in claim 2, basalt fiber, which is particularly excellent in tensile strength and is environmentally friendly, is used as the reinforcing fiber of the FRP reinforcing material made of fiber-reinforced plastic.

[0012] According to a third aspect of the present invention, there is provided the reinforced wood material according to the first aspect, wherein the FRP reinforcing material is provided in one or more strips at a portion of the wood material where a tensile force acts.

[0013] In the invention described in claim 3, the FRP reinforcing material is arranged at a location where a tensile force acts when the wood is used as a structural material. This allows the wood to be reinforced efficiently with the FRP reinforcing material. Also, by allowing one or more FRP reinforcing materials to be provided, the number of FRP reinforcing materials to be arranged can be changed according to the magnitude of the tensile force acting on the wood.

[0014] According to a fourth aspect of the present invention, there is provided the reinforced wood piece according to the first aspect, wherein the FRP reinforcing materials are arranged in a cross direction in a cross section perpendicular to the axial direction of the wood piece.

[0015] In the invention described in claim 4, the FRP reinforcing materials are arranged in a cross direction in a cross section perpendicular to the axial direction of the wood, so that it is possible to reinforce bending stress in all directions. In addition, because it is reinforced in all directions, it is possible to prevent bending (warping) of the wood due to drying. Furthermore, because the material has no directionality, it can be used in any direction without being aware of the tensile or compressive side. Effect of the Invention

[0016] As explained above in detail, according to the present invention, it is possible to improve the strength of wood by using a reinforcing material without impairing the appearance of the wood, and it is also possible to reliably improve the strength by increasing the bonding strength between the wood and the reinforcing material. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view of a reinforcing wood piece 1 according to the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 11 is a cross-sectional view of a reinforcing wood piece 1 according to a modified example. [Figure 4] 1A is a bending moment diagram for a beam supported at both ends, FIG. 1B is a continuous beam, and FIG. 1C is a cantilever beam, and the diagram shows the arrangement pattern of the FRP reinforcement material 4. [Diagram 5] FIG. 2 is a perspective view of a wooden piece 2 showing a warped state. [Figure 6] FIG. 2 is a cross-sectional view of reinforced wood 1 with FRP reinforcing materials 4 arranged in each of the cross directions. [Figure 7] 1A to 1C are side views of a piece of wood 2 illustrating the manufacturing process of the reinforced wood piece 1. [Figure 8] 1(A) and 1(B) are end views of a wooden piece 2 illustrating the manufacturing process of a reinforced wooden piece 1. FIG. [Figure 9] FIG. 2 is a perspective view of the reinforcing wood 1 with a strip material 5 arranged thereon. [Figure 10] 13 is a modified example (part 1) showing the arrangement pattern of FRP reinforcing material 4 in a beam supported at both ends. [Figure 11]13 is a modified example (part 2) showing the arrangement pattern of FRP reinforcing material 4 in a beam supported at both ends. [Figure 12] 1 is a plan view of the reinforced wood 1 showing a modified arrangement pattern of the FRP reinforcing material 4. FIG. [Figure 13] FIG. 2 is a perspective view showing a method for connecting reinforcing wood pieces 1 in series. [Figure 14] FIG. 2 is a perspective view showing a method for connecting reinforcing wood pieces 1 in parallel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0019] 1 and 2, the reinforced wood piece 1 according to the present invention is composed of a wood piece 2 made of a log and having a slit 3 cut along the axial direction, and an FRP reinforcing material 4 fixed with an adhesive into the slit 3. The reinforced wood piece 1 is a hybrid wood piece in which the wood piece 2 is incorporated with the FRP reinforcing material 4 made of a high-strength different material to improve its strength.

[0020] The shape of the wooden piece 2 is shown as a log in the illustrated example, but it may also be a drum-shaped piece of wood. The material and dimensions of the wooden piece 2 are arbitrary, and the wooden piece can be widely used for uses in the civil engineering field, such as horizontal members and wooden piles for retaining walls, and logs driven into the ground.

[0021] A slit 3 is provided along the axial direction on the peripheral surface of the wooden piece 2. The slit 3 is a groove portion formed with a predetermined depth and width from the surface of the wooden piece 2 toward the inside using a cutting tool such as a circular saw blade or a trimmer. The slit 3 extends in the same direction as the axial direction of the wooden piece 2, and has an inclination angle of 0° with respect to the axial direction.

[0022] The depth direction of the cut grooves 3 is formed almost perpendicular to the surface of the wooden piece 2, and in the case of a log having a circular cross section, the cut grooves 3 are formed from the outer peripheral surface toward the central axis C of the wooden piece 2 as shown in Fig. 2. When the cut grooves 3 are formed in a plurality of rows at intervals in the circumferential direction as shown in Fig. 3, each cut groove 3 may be formed almost perpendicular to the peripheral surface of the wooden piece 2 from a predetermined position on the outer peripheral surface toward the central axis C of the wooden piece 2 as shown in Fig. 3(A), or each cut groove 3 may be formed in parallel as shown in Fig. 3(B). When the depth direction of the cut grooves 3 is formed almost perpendicular to the surface of the wooden piece 2 as in the former case, the end face of the FRP reinforcing material 4 inserted into the cut grooves 3 that faces the wooden piece surface can be minimized, and the FRP reinforcing material 4 becomes less noticeable in appearance.

[0023] The depth D of the cut groove 3 is 1 / 2 or less, preferably about 1 / 4 to 1 / 2, of the radius r of the wooden piece 2. If the wooden piece 2 is a square timber, the depth D of the cut groove 3 is 1 / 4 or less, preferably about 1 / 8 to 1 / 4, of the length of the side extending in the depth direction.

[0024] The width W of the cut groove 3 varies depending on the size of the wooden piece 2, but is in the range of 2 to 20 mm, and preferably 3 to 10 mm.

[0025] The FRP reinforcing material 4 is a plate-shaped, strip-shaped, round bar-shaped (rod-shaped) or square bar-shaped member. In the embodiment shown in Fig. 1 and Fig. 2, the FRP reinforcing material 4 is formed with approximately the same dimensions as the slit 3, and is formed with a size such that when inserted into the slit 3, it is completely immersed inside the slit 3, and the end face of the FRP reinforcing material 4 faces from the opening of the slit 3. The FRP reinforcing material 4 is inserted into the slit 3 formed in the wooden piece 2 and fixed to the inside of the slit 3 with an adhesive. In this way, in the reinforced wooden piece 1 according to the present invention, the FRP reinforcing material 4 formed with approximately the same size as the slit 3 is inserted into the inside of the slit 3 and fixed with an adhesive, so that the FRP reinforcing material 4 is bonded to the wooden piece 2 at least on both side walls and the bottom surface of the slit 3. Therefore, compared to the conventional case where a reinforcing material is arranged on the surface of the wooden piece, it is fixed to the wooden piece over an area more than twice as large, and the reinforcing effect of the wooden piece 2 can be improved.

[0026] In the illustrated example, one FRP reinforcement material 4 is arranged in each cut groove 3, but multiple plate-shaped or strip-shaped FRP reinforcement materials 4 may be arranged in a stacked state, or multiple round or square bar-shaped FRP reinforcement materials 4 may be arranged in parallel.

[0027] The material of the FRP reinforcing material 4 is fiber reinforced plastic, which has advantages such as high tensile strength, light weight, a small difference in specific gravity with wood, and excellent corrosion resistance.

[0028] The reinforcing fibers of the fiber-reinforced plastic may be basalt fiber, carbon fiber, glass fiber, aramid fiber, etc. In particular, it is preferable to use environmentally friendly basalt fiber, which has excellent tensile strength and is made from basalt, a natural material.

[0029] As the matrix resin of the fiber reinforced plastic, it is preferable to use a thermosetting resin such as an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, or a phenol resin.

[0030] The fiber-reinforced plastic can be produced according to a conventional method, such as a continuous pultrusion molding method in which continuous reinforcing fibers in the form of threads are passed through a resin tank for an impregnation process, then heated and cured in a mold, and pulled out with a pultrusion device.

[0031] An epoxy resin adhesive is preferably used as the adhesive used to fix the FRP reinforcing material 4 in the cut groove 3. In addition, a wide variety of adhesives suitable for bonding wood and plastic can be used.

[0032] The arrangement of the FRP reinforcing material 4 relative to the wooden piece 2 varies depending on the support method of the reinforcing wooden piece 1 used as a structural material, and is arranged at a location that will be at least on the tensile side when stress is applied.

[0033] For example, when the reinforcing wood 1 is used as a cross member in earth retaining construction, both ends are supported by parent piles, and the reinforcing wood 1 is subjected to an almost uniform earth pressure from the side opposite the part supported by the parent piles over its entire length, the reinforcing wood 1 can be modeled as a beam supported at both ends that is subjected to an evenly distributed load over its entire length, as shown in Figure 4(A). In this case, the supporting surface side of the reinforcing wood 1 is in tension over its entire length, and the opposite surface is in compression over its entire length, so it is advisable to place the FRP reinforcing material 4 on the supporting surface side of the reinforcing wood 1 over its entire length.

[0034] As another example, when both ends are supported by parent piles as in the above example, and the middle part is also supported by parent piles, the reinforcing wood 1 can be modeled as a continuous beam with both ends and the middle part supported, with a uniformly distributed load over the entire length, as shown in Figure 4(B). In this case, the reinforcing wood 1 has a certain section from both ends where the support surface side is the tension side and the opposite side is the compression side, and a certain section including the middle support part has a compression side where the support surface side is the compression side and the opposite side is the tension side. Therefore, it is preferable to place the FRP reinforcing material 4 on the support surface side of the reinforcing wood 1 in each of the certain sections from both ends, and on the opposite side of the reinforcing wood 1 where the support surface side is the compression side.

[0035] When the reinforcing wood 1 is used as a wooden pile, it can be modeled as a cantilever beam that receives a uniformly distributed load over its entire length, as shown in Fig. 4(C). In this case, the side of the reinforcing wood 1 that receives earth pressure is in tension over its entire length, and the opposite side is in compression over its entire length, so it is advisable to place the FRP reinforcing material 4 over the entire length of the side of the reinforcing wood 1 that receives earth pressure.

[0036] In the example reinforced wood piece 1 shown in Figures 4(A) to (C), a plate-shaped FRP reinforcing material 4 having a cross-sectional shape with a long side and a short side is arranged on the tensile side of the wood piece 2, with the long side of the cross-sectional shape oriented in the direction in which the load acts. This increases the section modulus of the FRP reinforcing material 4 against external forces, and the reinforcing effect of the FRP reinforcing material 4 is greater than that of the conventional technology, in which the reinforcing material is arranged on the outer surface, which is the tensile side, with the cross-sectional shape oriented in the direction in which the load acts.

[0037] In the case where the end faces of the FRP reinforcing material 4 face the end faces of both axial ends of the wooden piece 2, which may cause a problem of poor appearance, the cut grooves 3 may be formed to a length that does not reach the end faces of both axial ends of the wooden piece 2, and may be formed only in the middle part of the wooden piece 2 in the axial direction, that is, between positions spaced axially inward from both end faces, so that the end faces of the FRP reinforcing material 4 are not visible from the end faces of both axial ends of the wooden piece 2. In this case, the preferred range of the distance between the edge of the cut groove 3 and the axial end faces of the wooden piece 2 is 10 to 50 mm. When such a problem of poor appearance does not occur, it is preferable to form the cut grooves 3 so as to reach the end faces of the wooden piece 2, and arrange the FRP reinforcing material 4 along the entire length of the cut grooves 3.

[0038] 4(B), when there is a section in the wooden piece 2 where the tension side and compression side are reversed, it is preferable to arrange the FRP reinforcements 4, 4 arranged on each tension side at the boundary sections so that they have an axial section where they overlap in a direction perpendicular to the axial direction, thereby preventing discontinuous sections of reinforcement. Note that, at these boundary sections, the edge shape of the FRP reinforcement 4 may be formed in a shape in which the FRP reinforcement 4 is cut almost vertically, as in the illustrated example, or may be formed so that the cross-sectional shape of both FRP reinforcements 4 becomes gradually or stepwise smaller in the axial section where the FRP reinforcements 4, 4 overlap.

[0039] Incidentally, the wood 2 may naturally warp due to drying and shrinkage, as shown in FIG. 5. In this case, the side with the greater shrinkage becomes the compression side, and the opposite side becomes the tension side. Although it is possible to predict to some extent which direction such warping will occur, it is difficult to accurately grasp. In addition, when the reinforced wood 1 is installed as a structural material, there are cases where the direction of the load it receives cannot be accurately grasped. Therefore, in order to prevent warping in any direction and to enable use without being aware of the direction of the load it receives, as shown in FIG. 6, the FRP reinforcement members 4 can be provided in a cross direction in a cross section perpendicular to the axial direction of the wood 2. That is, the FRP reinforcement members 4 are arranged at 90° intervals with respect to the circumferential direction of the wood 2. By arranging the FRP reinforcement members 4 in the cross direction, it is possible to reinforce the bending stress and prevent the wood 2 from bending (warping) due to drying. In addition, by eliminating the directionality of the material, it can be used in any direction without being aware of the tension side or compression side.

[0040] To manufacture the reinforced wood 1, as shown in FIG. 7, a cut groove 3 of a predetermined depth is formed parallel to the axial direction of the wood 2 using a circular saw blade 10 or the like, and then, as shown in FIG. 8(A), adhesive is applied to this cut groove 3 and an FRP reinforcing material 4 is inserted and fixed (FIG. 8(B)).

[0041] The reinforced wood 1 having the above-described configuration is composed of wood 2 having a cut groove 3 along the axial direction and FRP reinforcing material 4 fixed into the cut groove 3 with an adhesive. Therefore, the FRP reinforcing material 4 is not very noticeable in appearance, and the strength can be improved by the FRP reinforcing material 4 without compromising the aesthetic appearance of the wood.

[0042] Furthermore, since the FRP reinforcement material 4 is fixed into the cut groove 3 with an adhesive, the surface of the FRP reinforcement material 4 facing the inner surface of the cut groove 3 is fixed to the wooden material 2, increasing the bonding strength between the wooden material 2 and the FRP reinforcement material 4, thereby ensuring that the wooden material 2 is reinforced by the FRP reinforcement material 4. [Other examples] (1) When the reinforcing wood 1 is deformed by an external force, the opening of the cut grooves 3 due to the deformation causes the reinforcing effect of the FRP reinforcing material 4 to decrease. In order to prevent this, as shown in FIG. 9, a plurality of strips 5 can be arranged at intervals in the axial direction to wrap around the outer periphery of the reinforcing wood 1 to which the FRP reinforcing material 4 is fixed in the cut grooves 3. The strips 5 are annular members that are wrapped around the outer periphery of the reinforcing wood 1 in the circumferential direction and fastened tightly, and are intended to tightly fasten the reinforcing wood 1 so that the cut grooves 3 do not open. The strips 5 can be made of a fiber-reinforced plastic plate, a plastic plate, a metal plate, wood, or the like. The strips 5 are fixed to the outer periphery of the reinforcing wood 1 with an adhesive. A recess can be formed in the circumferential direction at the portion of the reinforcing wood 1 where the strips 5 are to be arranged, and the strips 5 can be fitted into the recesses. The reinforcing wood pieces 1 may be arranged at any interval in the axial direction, but are preferably arranged at intervals of 0.5 to 1 m in order to make the band material 5 less noticeable in appearance and to prevent the cut grooves 3 from opening up.

[0043] (2) In the above embodiment, the FRP reinforcement 4 is formed with a constant width in the axial direction of the reinforcing wood 1, but the width of the FRP reinforcement 4 (the length dimension in the depth direction of the slit 3) may be changed according to the magnitude of the bending moment generated in the beam. To explain this in detail, taking an example of a beam supported at both ends, as shown in FIG. 10, the bending moment diagram of a beam supported at both ends is maximum at the center between the two supports, and is an arch shape that becomes smaller toward the support side. Therefore, the width of the FRP reinforcement 4 can be formed into an arch shape that is maximum at the center between the two supports and becomes smaller toward the support side in accordance with the shape of the bending moment diagram. Only one edge that is the bottom side of the slit 3 is formed into such an arch shape, and the other edge on the peripheral side of the reinforcing wood 1 is formed in a straight line along the axial direction of the reinforcing wood 1. As a result, the resistance to the bending moment becomes large in the center between the supports where the width of the FRP reinforcement 4 is large, and a large reinforcing effect can be reliably obtained with the minimum necessary amount of FRP reinforcement 4 material.

[0044] Using the same concept, the number of FRP reinforcement material 4 arranged may be changed depending on the magnitude of the bending moment generated in the beam, specifically, as shown in Fig. 11, in a predetermined section X in the center where the bending moment is large, multiple strips of FRP reinforcement material 4 may be arranged (Fig. 11(B)), and in the other sections at both ends, only one strip may be arranged (Fig. 11(C)). Alternatively, in the predetermined section X in the center, multiple layers of FRP reinforcement material 4 may be arranged, and in the other sections at both ends, only one layer of FRP reinforcement material 4 may be arranged.

[0045] (3) In the above embodiment, when one side of the wooden piece 2 is the tension side over the entire axial length, such as in a double-supported beam or a cantilever beam, the slit 3 is formed continuously over almost the entire length of the wooden piece 2 on the tension side, and the continuous FRP reinforcement material 4 is fixed in the slit 3. However, the slit 3 may be divided in the middle and arranged at adjacent positions, so that a plurality of FRP reinforcement materials 4 are arranged discontinuously in the axial direction of the reinforced wooden piece 1. For example, as shown in FIG. 12, a plurality of FRP reinforcement materials 4 of a predetermined length can be arranged in a zigzag pattern on both sides across the central axis C of the wooden piece 2. As a result, the slits 3 are not continuous in the axial direction but are provided discontinuously, so that the effect of the strength of the wooden piece itself being reduced by forming the slits 3 over the entire length of the wooden piece 2 can be reduced. The length of each FRP reinforcement material 4 is preferably about 1 / 10 to 1 / 2 of the entire length of the wooden piece 2. Moreover, the distance between adjacent FRP reinforcing materials 4, 4 in the circumferential direction is preferably 10 to 100 mm.

[0046] (4) When connecting multiple reinforcing wood pieces 1 adjacent in the axial direction in series, the FRP reinforcement material 4 of one of the adjacent reinforcing wood pieces 1 may be arranged to protrude from the axial end edge toward the other wood piece 2, and this protruding portion of the FRP reinforcement material 4 may be fixed into the slit 3 of the other wood piece 2, so that the FRP reinforcement material 4 is arranged to straddle the two axially adjacent wood pieces 2, 2. This can increase the joint strength between the reinforcing wood pieces 1 adjacent in series.

[0047] (5) When connecting multiple diametrically adjacent reinforcing wood pieces 1 in parallel, as shown in Fig. 14, the FRP reinforcement material 4 of one of the diametrically adjacent reinforcing wood pieces 1 may be arranged to protrude from the outer periphery toward the other wooden piece 2, and the protruding portion of the FRP reinforcement material 4 may be fixed into the slit 3 of the other wooden piece 2, so that the FRP reinforcement material 4 is arranged to straddle the diametrically adjacent wooden pieces 2, 2. This can increase the joint strength between the reinforcing wood pieces 1 adjacent in parallel. [Explanation of symbols]

[0048] 1...Reinforcement wood, 2...Wood, 3...Slit, 4...FRP reinforcement

Claims

1. A reinforced wood material is made of a log material, characterized in that it comprises a wood material having a slit groove formed along an axial direction, and an FRP reinforcing material fixed into the slit groove with an adhesive.

2. 3. The reinforced wood material according to claim 2, wherein basalt fiber is used as the reinforcing fiber of said FRP reinforcing material.

3. 2. The reinforced wood material according to claim 1, wherein the FRP reinforcing material is provided in one or more strips at a portion of the wood material where a tensile force acts.

4. The reinforced wood piece according to claim 1 , wherein the FRP reinforcing materials are arranged in a cross-sectional manner perpendicular to the axial direction of the wood piece.

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