JP2020133212A - Woody building material - Google Patents

Abstract

To provide woody building material allowing long woody building material excellent in rigidity and strength to be obtained through connecting and integrating at least two laminated lumbers at site in a longitudinal direction and installation thereof in a simple way.SOLUTION: Woody building material is configured to connect at least two woody laminate lumbers 41 in a longitudinal direction, wherein the woody laminate lumber 41 is strengthened with a pipe-like reinforcement member penetrating through its longitudinal direction, and a tendon 44 is arranged in a pipe of the pipe-like reinforcement member to penetrate in the longitudinal direction within pipes of the pipe-like reinforcement members of the at least two woody laminate lumbers 41 to be fixed in a connected state of the at least two woody laminate lumber 41 in the longitudinal direction by tension applied to the tendon 44.SELECTED DRAWING: Figure 4

Description

The present invention relates to wood building materials.

Conventionally, laminated lumber, which is made by laminating a single piece of wood, a pulling plate (lamina) or a small square timber that has been cut long in the fiber direction of the wood, with the fiber directions parallel to each other using an adhesive, is mainly used in construction. It is used as a frame material such as pillars and beams, or for wooden bridges and large dome.

In particular, laminated lumber is excellent in that it has a high degree of freedom in size and shape because it is laminated with ground lumber and small square lumber, there is little variation in product strength, dry cracks, deviation, etc., and it is easy to manufacture bent lumber. Has characteristics.

However, when these laminated woods are used for large buildings and structures, it is necessary to increase the rigidity and strength of the laminated woods, so the thickness of the laminated woods must be increased, and as a result, the buildings and structures. The ceiling of the building is low, and excessive thickness design is required. As a countermeasure, it has been proposed to use a reinforced single wood or reinforced laminated wood in which a reinforcing material having high rigidity and strength is integrated with an adhesive or the like.

Various materials such as metal and fiber are used as the reinforcing material. For example, in Patent Document 1, a prepreg using carbon fiber is used as the reinforcing fiber, and both sides thereof are impregnated with thermosetting resin. A method of pasting and integrating a wood-based sheet and using it as a composite sheet is disclosed. In the present invention, a composite sheet containing the reinforcing fibers is further adhered to wood, and a wood laminated wood having excellent wood adhesiveness, handleability, and processability is disclosed.

However, in the method of reinforcing rigidity and strength only by combining reinforcing materials such as metal and fiber, the degree of reinforcement changes depending on the amount of reinforcing material added, so that it is used for large buildings and structures. And if strength is required, more reinforcement material needs to be compounded. In addition to the increase in material cost as the number of materials to be composited increases, it becomes difficult to guarantee the adhesive strength of the reinforcing material, and the compounding process becomes complicated.

Attempts have been made to solve this problem. For example, Patent Document 2 discloses a wood building material made of wood laminated wood reinforced by a tubular reinforcing material.

The larger a building or structure is, the longer the building material of its component, especially the building material used as a beam, is required. The length of building materials used in detached houses is about 4,000 mm to 6,000 mm, but for large buildings and structures, for example, 6,000 mm, and in the longest case, 18,000 mm or more. A length of building material is required.

In this case, it is used as a long building material by joining a plurality of laminated lumber of 6,000 mm or less in the longitudinal direction, and as a typical construction method, a construction method using an iron plate and a bolt or a reinforcing bar A glue-in rod method using an adhesive is known.

However, these construction methods are very complicated and cannot be applied to laminated wood whose rigidity and strength are reinforced by combining reinforcing materials such as metal and fiber in the first place. This is because the iron plates, bolts, reinforcing bars, etc. used for joining may come into contact with or interfere with the reinforcing material of laminated wood, and in that case, there is a concern that the strength will be significantly reduced, and wood-based materials that do not contain reinforcing material in the first place. This is because it is difficult for the rigidity and strength of the joint to exceed the rigidity and strength of ordinary wood-based laminated wood because it is a joining method of wood-based laminated wood consisting of only one piece.

Japanese Unexamined Patent Publication No. 9-254319 JP-A-2018-89897

An object of the present invention is to provide a long wood building material having excellent rigidity and strength, in which wood laminated wood reinforced with a reinforcing material is joined in the longitudinal direction without impairing its physical properties.

That is, the present invention is a wood building material in which at least two wood laminated woods are joined in the longitudinal direction, and the wood laminated wood is reinforced by a tubular reinforcing material penetrating in the longitudinal direction. A tension material is provided that penetrates the inside of the tubular reinforcing material of at least two wood glulam in the longitudinal direction, and the tension material is tensioned to fix the at least two wood glulam in a state of being joined in the longitudinal direction. It is a wood-based building material that has been used.

According to the present invention, it is possible to provide a long wood building material having excellent rigidity and strength, in which wood laminated wood reinforced with a reinforcing material is joined in the longitudinal direction without impairing its physical properties.

Schematic diagram of wood laminated wood of Examples 1 and 2 (cross-sectional view in a plane orthogonal to the length direction) Schematic diagram of wood laminated wood of Comparative Example 1 (cross-sectional view on a plane orthogonal to the length direction) Schematic diagram of wood laminated wood of Comparative Example 2 (cross-sectional view on a plane orthogonal to the length direction) Schematic diagram of wood laminated wood and washer of Example 1 and Comparative Example 1 Schematic diagram of wood laminated wood and washer of Example 2 Schematic diagram of wood laminated wood of Comparative Example 2

[Wood laminated wood]
Wood-based laminated wood is a wood-based material composed of wood-based material pieces (lamina) bonded to each other with an adhesive, and is made of single wood or a pulling board or small square wood that has been cut long in the fiber direction of the wood. It is used as a piece of material (lamina), and the fiber directions of these pieces of wood-based material are parallel to each other and bonded together using an adhesive.

In the present invention, in order to reinforce the wood laminated wood, a tubular reinforcing material is used as a component of the wood laminated wood. In the reinforced wood laminated wood, the tubular reinforcing material and the wood material piece (lamina) are arranged so that the length direction of the tubular reinforcing material and the fiber length direction of the wood material piece (lamina) are parallel to each other. Therefore, it is preferable that the reinforced laminar is formed by adhering them so as to be in contact with each other in the width direction, and the wood lamina is composed of only a piece of wood material (lamina).

The wood-based laminated wood in the present invention is preferably one in which a reinforcing lamina containing a tubular reinforcing material as a component and a wood-based lamina composed of only a piece of wood-based material (lamina) are laminated. It is preferable that the length direction of the reinforcing lamina in this wood laminated wood and the grain direction of the wood material piece (lamina) coincide with the fiber direction of the fiber reinforced resin of the tubular reinforcing material. That is, it is preferable that the tubular reinforcing material and the wood-based material piece (lamina) are adhered in a direction in which the fiber directions are parallel to each other.

[Tubular reinforcement]
The tubular reinforcing material is made of a material having strength and rigidity capable of reinforcing wood laminated wood, that is, a material having higher strength and rigidity than a piece of wood material (lamina). For example, a fiber reinforced resin composed of a metal such as iron or aluminum, a reinforcing fiber and a resin can be used. The tubular reinforcing material is preferably made of a fiber reinforced resin and has a length thereof because it can exert excellent effects on compatibility with wood, for example, coefficient of thermal expansion, thermal conductivity, anisotropy of material properties, weight, and the like. It is preferable that the reinforcing fibers are oriented in the direction and fixed with a cured product of a thermosetting resin.

A tension material is passed through at least one of the tubular reinforcing materials. Therefore, the inside of the tubular reinforcing material may be filled with a filler in a manner that does not hinder the action of the tensioning material, but it is preferable that nothing is filled and the tubular reinforcing material is hollow.

[Matrix resin]
When the tubular reinforcing material is made of a fiber reinforced resin, the matrix resin of the fiber reinforced resin is preferably a thermosetting resin. Examples of thermosetting resins include phenolic resins, epoxy resins, and vinyl ester resins. Of these, vinyl ester resin is preferable from the viewpoint of physical properties, processability, and final adhesiveness to wood.

[Reinforcing fiber]
When the tubular reinforcing material is made of a fiber reinforced resin, a reinforcing fiber having a strength suitable for reinforcing wood can be used as the reinforcing fiber. Since the wood building material of the present invention is used as a member for building a building, it is preferable that the strength does not decrease even in the event of a fire. Therefore, the reinforcing fibers are preferably organic fibers or inorganic fibers having a melting point or a glass transition temperature of 200 ° C. or higher, and these are preferably continuous fibers.

Examples of the reinforcing fiber include carbon fiber, aromatic polyamide fiber (aramid fiber), polyarylate fiber, polyparaphenylene benzobisoxazar fiber, polyphenylene sulfide fiber, polyimide fiber, ethylene tetrafluoride fiber, and glass fiber. Can be done. As the reinforcing fiber, carbon fiber, glass fiber or aromatic polyamide fiber is preferable. These reinforcing fibers may be used alone or in combination of two or more.

Among the reinforcing fibers, carbon fibers are particularly preferable in the present invention. Of these, acrylic nitrile-based carbon fibers obtained by firing polyacrylonitrile-based fibers are most preferable. Further, it is preferable that the carbon fiber has a nitrogen content of 0.1 to 15% by weight, a tensile strength of 2500 to 7000 MPa, and an elastic modulus of 150 to 700 GPa. In particular, a carbon fiber having a nitrogen content of 3 to 10% by weight, a tensile strength of 3500 MPa or more and an elastic modulus of 200 to 350 GPa and a diameter of 5 to 9 μm is optimal from the viewpoint of adhesiveness. Further, the oxygen / carbon ratio of the surface of such carbon fiber surface by the ESCA surface analyzer (manufactured by Shimadzu Corporation) is preferably 0.1 / 1 to 0.3 / 1. Further, the range of 0.15 / 1 to 0.25 / 1 is preferable from the viewpoint of ensuring high adhesive strength with the resin.

The reinforcing fibers preferably have a fiber diameter of 5 to 9 μm, but are more preferably fiber bundles. The fiber bundle is preferably a fiber bundle (strand) having 1000 to 300,000 constituents. Further, when the reinforcing fiber is a fiber bundle, it is preferable to use the fiber bundle by desired fractionation or widening to a desired shape.

In the present invention, it is preferable that such reinforcing fibers form a tubular reinforcing material together with a resin, but the form of the reinforcing fibers in the tubular reinforcing material is a UD base material in which the fibers are aligned in one direction or two directions thereof. Various forms such as the above combinations, woven fabrics, and non-woven fabrics can be adopted, and can be designed according to the required strength. However, when the balance between actual performance and cost is taken into consideration, it is particularly preferable to use it as a UD base material aligned in one direction. As the UD base material, it is preferable to use a UD base material in which carbon fibers having high tensile strength and tensile elastic modulus and high heat resistance are aligned in one direction.

The reinforcing fibers are preferably oriented in the length direction of the tubular reinforcing material. And it is preferable that the reinforcing fiber is a continuous fiber. By using such a fiber form, the reinforcing effect of the fiber can be more effectively exhibited.

[Physical properties of tubular reinforcing material]
The volume fraction of the reinforcing fiber and the resin in the tubular reinforcing material is preferably in the range of 40/60 to 60/40. Further, the abundance density of the reinforcing fibers in the tubular reinforcing material is preferably in the range of 10,000 to 18,000 fibers / mm ² in the cross section in the length direction thereof.

In the tubular reinforcing material, the balance between the tensile physical properties and the compressed physical properties in the fiber direction is important from the viewpoint of reinforcing the bending physical properties of the wood laminated wood. In order to prevent brittle fracture, which is a more preferable fracture form, from the wood laminated wood reinforced by the tubular reinforcing material, it is important that the compressive strength of the tubular reinforcing material is smaller than the tensile strength. .. Specifically, the tensile strength is preferably 500 to 5,000 MPa, more preferably 1,000 to 4,500 MPa. On the other hand, the compressive strength is preferably lower than the tensile strength and 100 to 5,000 N / mm, and more preferably lower than the tensile strength and 500 to 4,500 N / mm.

In the tubular reinforcing material, it is preferable that the reinforcing fibers are mainly arranged in the peripheral portion of the tubular reinforcing material. By arranging the reinforcing fibers around the tubular reinforcing material, it is possible to improve the reinforcing effect of the tubular reinforcing material in the wood laminated wood. Here, the peripheral portion refers to the range of 1/3 of the outer peripheral portion of the tubular reinforcing material, and particularly refers to the range of 1/5.

In the present invention, the shape of the tubular reinforcing material is tubular, and the content of the reinforcing fibers can be easily adjusted by controlling the wall thickness of the tubular reinforcing material. By making the tubular, that is, the reinforcing material itself hollow, the physical properties required for the tubular reinforcing material can be optimally controlled by the wall thickness of the layer forming the tube, and excessive use of reinforcing fibers and matrix resin can be used. Can be avoided and the weight of the reinforcing fiber can be reduced.

[Cross-sectional shape of tubular reinforcing material]
It is also preferable that the shape of the tube-shaped reinforcing material is rectangular. On the other hand, for example, when the cross section of the tubular reinforcing material is circular, the shape of the tubular reinforcing material as a whole becomes columnar, and a gap is likely to be formed between the tubular reinforcing material and the surrounding wood-based material piece (lamina), and the adhesive strength is reduced. There is a tendency. A particularly preferred cross-sectional shape of the tubular reinforcement is a square or rectangular hollow hollow.

On the other hand, the inner side of the tubular reinforcing material is arbitrary and can be preferably used even if it is not rectangular. For example, when the inside of a tubular reinforcing material having a rectangular cross section has a circular cross section, it is possible to design a large wall thickness of the tubular reinforcing material, which is an effective means when it is desired to increase the tensile strength and compressive strength of the tubular reinforcing material. Become.

When the tubular reinforcing material is rectangular, the cross-sectional dimensions thereof are preferably 10 to 50 mm on the short side and 10 to 500 mm on the long side. Further, it is preferable that the outer dimension of the short side is 15 to 45 mm and the outer dimension of the long side is 15 to 400 mm, and it is preferable in manufacturing that the short side does not exceed the thickness of the reinforcing laminar constituting the laminated wood.

When the tubular reinforcing material is rectangular and hollow (the inside is also rectangular), the thickness of each side of the tubular reinforcing material is preferably 1 to 30 mm, more preferably 2 to 25 mm. If the thickness is thinner than this, buckling fracture may occur on the vertical side of the tubular reinforcing material when a force is applied in the bending direction, and a sufficient reinforcing effect may not be obtained. Not preferred. On the other hand, if it is thicker than this, there is an increased concern that the resin inside cannot be sufficiently cured when molding the tubular reinforcing material, and when a force is applied in the bending direction, shear failure in the tubular reinforcing material is likely to occur. There is a concern that it will be unfavorable. This tendency is particularly remarkable when used as a beam.

[Arrangement]
The arrangement of the tubular reinforcing material in the wood laminated wood is either a mode in which a plurality of tubular reinforcing materials are arranged equidistant from the center of the cross section of the wood laminated wood, or a tubular reinforcement point-symmetrical with respect to the center of the wood laminated wood. It is preferable that a plurality of materials are arranged. In particular, it is preferable that two or four tubular reinforcing members are arranged at equidistant positions from the center of the cross section of the wood laminated wood. The rigidity of the wood laminated wood can be improved by arranging the wood laminated wood equidistantly from the center of the cross section. Further, from the viewpoint of the moment of inertia of area, the arrangement of the tubular reinforcing material in the wood laminated wood is preferably at a position close to the upper surface and the lower surface of the wood laminated wood, and this arrangement is particularly preferable when used as a beam.

The reinforcing lamina including the tubular reinforcing material may be arranged on the outermost layers (upper surface and lower surface) of the wood laminated wood, but when the wood building material of the present invention is used as a beam, the tubular reinforcing material can be seen from above or below. It is preferable to arrange it inward by one layer or more of lamina from the outermost layer in order to prevent it. The number of tubular reinforcing materials that can be used can be designed as needed. For example, a total of two tubular reinforcing materials, one above the center of the cross section of the wood laminated wood with a long vertical cross section and one below. It may be present, and the upper one and the lower one may be replaced with two arranged side by side. Specifically, it is preferable to arrange a total of four tubular reinforcing materials, two above the center of the cross section of the wood laminated wood and two below, and just inside the four corners in the cross section of the wood laminated wood. It is particularly preferred to place a tubular reinforcement. When the tubular reinforcement is placed just inside the four corners of the cross section of the wood laminated wood, a space where nails and bolts can be used from the upper surface of the wood laminated wood (a place where there is no tubular reinforcement and it is molded only with wood). This is a particularly preferable mode for a field foot used as a beam because a larger amount can be secured.

It is preferable that the top, bottom, left and right surfaces of the wood laminated wood are smooth. In the wood building material of the present invention, the upper and lower surfaces of the wood laminated wood and the laminated cross sections on the left and right in the length direction can be surface-cut with a moulder or the like to form a smooth surface of the member. Normally, when wood is reinforced with other materials, the other materials are exposed on the surface and smoothing treatment is difficult. However, in the present invention, since the reinforcing material is arranged inside the wood laminated wood, it is easy. A smooth surface can be obtained.

The size of wood laminated wood is generally in the range of 2,850 to 18,000 mm in the length direction, 105 to 240 mm in the width direction, and 120 to 2,000 mm in the thickness direction. It can be set arbitrarily even if it is out of the range.

〔adhesive〕
It is preferable that the tubular reinforcing material is integrated with a wood-based material piece (lamina) to form a reinforcing lamina. As the adhesive to be used, any adhesive such as an epoxy adhesive or an acrylic adhesive that can bond wood and resin can be used. From the viewpoint of integration into wood laminated wood, it is preferable to use a water-soluble polymer-isocyanate adhesive or resorcinol adhesive used for producing laminated wood in order to reduce the process cost. The bonding method can be selected according to the reaction of the adhesive and may be pressed at room temperature, but the method of bonding at a high frequency in a short time is particularly preferable from the viewpoint of reducing the process cost. Further, in order to further enhance the adhesive effect, it is also useful to make the surface of the tubular reinforcing material uneven to increase the adhesive area.

[Tension material]
In the wood building material of the present invention, a tubular reinforcing material is arranged inside the wood laminated wood, and prestress is applied in the longitudinal direction of the wood laminated wood constituting the wood building material by using a tensioning material.

As the tension material, PC steel materials such as PC steel wire, PC steel stranded wire, and PC steel rod used in general prestressed concrete can be used. Further, a tension material having high tensile strength and creep performance may be used, and carbon fiber, aromatic polyamide fiber (aramid fiber), polyallylate fiber, polyparaphenylene benzobisoxazar fiber, polyphenylene sulfide fiber, and polyimide may be used. It may be an FRP (fiber reinforced plastics) rod, a fiber rope, or a fiber cable using high-performance fibers such as fibers, ethylene tetrafluoride fibers, and glass fibers.

The tension material is installed in such a manner that it passes through the tube of the tubular reinforcing material that reinforces the wood laminated wood and penetrates in the longitudinal direction. At this time, washers are provided at both ends of the connecting body of the wood laminated wood which is joined by joining the wood laminated wood in the longitudinal direction, and the washers at both ends are connected by the tension material, and tension is applied to the tension material to apply tension to the wood laminated wood. Is fixed in the state of being joined in the longitudinal direction. Therefore, the wood building material of the present invention is fixed in a state where at least two wood laminated materials are joined in the longitudinal direction.

The tensioning material may be passed through the center of the cross section of the wood laminated wood, but it is preferable to pass a plurality of tensioning materials at a position equidistant from the center and point-symmetrical with respect to the center. For example, in the case of arranging four tubular reinforcing materials equidistant from the center of the cross section of the wood laminated wood and at a position symmetrical with respect to the center, the wood laminated wood is passed through all four tubular reinforcing materials with tensioning material. Is preferably joined in the longitudinal direction. The tension material through which each tubular reinforcing material is passed may be one or two or more.

In this joining, it is important to apply compressive force from both ends of the wood laminated wood to which the wood laminated wood is connected via a washer when tension is applied to the tension material, and to crimp the wood laminated wood to each other. By realizing high crimping, the portion where one wood laminated wood and the other wood laminated wood are joined can be brought closer to a more integrated state, and the bending characteristics of the joint can be improved.

The tension applied to the tension material is 10 to 300 kN, preferably 30 to 250 kN, per tension material. If the tension is less than 10 kN, the crimping between the wood laminated wood will be insufficient, and the rigidity and strength at the joint of the wood laminated wood may not be sufficiently developed. On the other hand, if the tension exceeds 300 kN, the wood will be compressed. The edge of the laminated wood and the joint surface between the crimped wood laminated wood may be sunk and broken, and as a result, the rigidity and strength at the joint of the wood building material of the present invention may not be sufficiently exhibited.

In the present invention, the wood laminated wood is joined by passing a tensioning material through a tubular reinforcing material and applying prestress, so that the wood building material can be easily and efficiently obtained even at a construction site using the wood building material of the present invention. .. That is, it is possible to bring the wood laminated wood before joining to the site where the building is constructed and join the wood laminated wood at the site to obtain the wood building material of the present invention. In this case, even if the carry-in route is narrow, the wooden building materials required for construction can be joined at the site. In addition, since it is possible to divide a long and heavy wood building material into small and lightweight wood laminated wood and carry it in to obtain a wood building material of the required length at the site, for example, it is necessary to rely on manual carrying in. Even in a place, you can get a long wooden building material on site.

In the present invention, a metal dowel or the like may be used by making a counterbore hole in or near the center of the cross section of the wood laminated wood in order to improve workability. In this case, it is effective to prevent misalignment between the wood laminated wood during work and to provide auxiliary shear reinforcement at the joint of the wood laminated wood.

[Reinforcing material]
In the wood building material of the present invention, it is preferable that at least two wood laminated materials are joined via a recessed reinforcing material provided at the joint portion between the two. In this case as well, a tension of 10 to 300 kN is applied to the tension material. The embedded reinforcing material is a reinforcing material that prevents the joint surfaces of the laminated wood materials from being locally embedded.

The higher the proof stress of the joint surface between the wood laminated wood, the larger the pressure can be applied to the wood laminated wood, and the higher the tension can be applied to the tension material. That is, by joining via a recessed reinforcing material, a joint portion having higher rigidity and strength can be obtained, and a wooden building material having higher rigidity and strength can be obtained.

The shape of the dented reinforcing material may be, for example, a flat plate shape or a shape covering the end portion of the wood laminated wood. The surface of the reinforcing material may be smooth or uneven. When there is unevenness, it is preferable that the reinforcing material on one side and the reinforcing material on the other side mesh with each other.

As the material of the digging reinforcing material, a material having a smooth surface and having a higher digging strength than the wood laminated wood can be used. Specifically, a fiber reinforced resin reinforced with carbon fiber, glass fiber or aromatic polyamide fiber, a metal material such as iron, aluminum or stainless steel, and an inorganic material such as a cement material such as concrete or mortar can be used.

[Fixing tension material]
In this state, the wood building material of the present invention is obtained by fixing the end of the wood laminated wood with bolts, nuts, wedge hardware, etc. via a washer while applying tension so that the tension material does not loosen. As the fixing method, the method used in the general prestressed concrete construction method can be used.

A preferred embodiment of the present invention is a tension material penetrating at least two, preferably four, of a plurality of tubular reinforcing materials arranged at equal distances from the center of a cross section orthogonal to the longitudinal direction of the wood laminated wood. The tension material is provided at a position symmetrical with respect to the center of the cross section orthogonal to the longitudinal direction of the wood laminated wood, and the tension material is passed through all the tubular reinforcing materials, and all of them are provided. In this mode, the wood laminated wood is joined via a recessed reinforcing material, the same tension is applied to the tension material in the range of 10 to 300 kN, and the wood laminated wood is fixed in a state of being crimped to each other. In this case, the tubular reinforcing material is preferably located near the upper surface and the lower surface of the wood laminated wood.

Hereinafter, the present invention will be specifically described with reference to Examples. Various physical properties were measured by the following methods.
(1) Compressive Strength of Tubular Reinforcing Material A measurement sample having a width of 10 mm, a length of 50 mm, and a thickness of 3 mm was cut out from the fiber-reinforced tubular reinforcing material. A stainless steel compression terminal with a length of 2 mm and a width of 4 mm is placed from above in a direction orthogonal to the length direction of the reinforcing material, compressed at a compression rate of 0.5 mm / min, and the maximum load (N) when the sample is destroyed. Was measured.

(2) Tensile Strength of Tubular Reinforcing Material A measurement sample having a width of 25 mm, a length of 200 mm and a thickness of 3 mm was cut out from the fiber-reinforced tubular reinforcing material. The grip portion was 35 mm, the sample was pulled at a tensile speed of 2 mm / min, and the maximum load (N) when the sample was broken was measured.

(3) Bending strength and flexural modulus of wood laminated wood The bending strength and flexural modulus of laminated wood were measured according to JAS Z2101. That is, the distance between the fulcrums was set to 18 times the beam formation, and a four-point bending test was carried out in which a load was applied to each of the points where the distance between the fulcrums was divided into three equal parts. Bending strength and flexural modulus were calculated by the following formulas, respectively.

Bending strength (1):

ただし、
ｐ：最大荷重
Ｌ：支点間距離
Ｌ_１：荷重点間距離
ｂ：試験体幅
ｈ：試験体厚み（梁成）
ΔＦ：最大荷重の１０％−最大荷重の４０％間の荷重増分
Δｙ：ΔＦに対応するたわみ増分
である。 Flexural modulus (2):

However,
p: Maximum load
L: Distance between fulcrums
L ₁ : Distance between load points
b: Specimen width
h: Specimen thickness (beam formation)
ΔF: Load increment between 10% of maximum load and 40% of maximum load
Δy: Deflection increment corresponding to ΔF.

(4) Prestress tension A compression sensor was placed between the washer and the nut to fix the tension material, and the pressure between the washer and the nut was measured to obtain the tension of the tension material.

(5) Bending strength and bending elasticity of joints between wood laminated wood A joint between wood laminated wood was created in the center of the test piece, the distance between fulcrums was set to 3,180 mm, and left and right from the joint between wood laminated wood. A repeated bending test was carried out in which a load was applied to each of the 150 mm locations. The repetition is performed in the order of 1/300, 1/250, 1/200, 1/150, 1/100, 1/50, 1/30, 1/15, 1/10 of 1,440 mm corresponding to the bending moment distance. The test was performed so that the amount of deflection increased with each repetition.

<Calculation of bending strength>
In the repeated bending test up to 1/10, when the fracture occurred, that point was set as the maximum load (p). When the fracture did not occur in the repeated bending test up to 1/10, a load was applied until the fracture occurred at the end of the test to obtain the fracture point = maximum load (p). The bending strength was calculated by the formula (1) using the obtained maximum load (p).

<Calculation of flexural modulus>
Using the stress-flexure curve obtained by the repeated test, the yield point was analyzed by the following procedure.
(1) The points at 10% (0.1p), 40% (0.4p), and 90% (0.9p) with respect to the maximum load (p) at the time of fracture are plotted on the stress-deflection curve. 0.1p and 0.4p, 0.4p and 0.9p are connected by a straight line, respectively.
(2) Plot the intersection of the straight line connecting 0.4p and 0.9p in parallel until it touches the stress-flexion curve and the straight line connecting 0.1p and 0.4p, and laterally from that point. The point of translation in the axial direction and the intersection with the stress-flexion curve was defined as the yield point.

Using the obtained yield point, the flexural modulus was calculated by the equation (2). Here, ΔF in the equation (2) was calculated as the load increment between the origin and the yield point of the stress-deflection curve, and Δy was calculated as the deflection increment corresponding to this ΔF.

(Example 1)
As a tubular reinforcing material, a matrix resin using carbon fiber (manufactured by Toho Tenax Co., Ltd., acrylic nitrile carbon fiber "HTS40, 24K", diameter 7 μm) as a reinforcing fiber is a vinyl ester resin (curing temperature 110 to 150 ° C., curing required. A pultruded material having a time of 5 to 10 min) was produced. The volume ratio of the reinforcing fibers and the matrix resin in this tubular reinforcing material was 60/40, and the abundance density of carbon fibers in the cross section was 15,000 fibers / mm ² . The cross-sectional shape of the tubular reinforcing material was a hollow square (rectangle), the outer dimensions were 30 mm × 30 mm, and the thickness was uniform on all sides and 3 mm (inner diameter 24 mm square). The tensile strength of the tubular reinforcing material was 1,400 MPa, and the compressive strength was 640 MPa.

A water-soluble polymer-isocyanate adhesive (manufactured by Oshika Corporation, PI Bond 5300L) is applied at 250 g / m ² in the groove of wood lamina (cedar) with a width of 30.5 mm and a depth of 14.5 mm. It was applied in an applied amount, and the above-mentioned tubular reinforcing material was sandwiched between the grooves of the wood lamina and bonded. Adhesion was performed by pressing at room temperature, the pressing pressure was 0.8 MPa, and the pressing time was 30 minutes. The reinforcing lamina obtained here has a width of 18 mm wood-30 mm tubular reinforcing material-30 mm wood-30 mm tubular reinforcing material-18 mm wood in which tubular reinforcing materials and wood are alternately arranged in the width direction. It was 126 mm lamina.

The obtained reinforced lamina was used for the bottom and top tiers, and in the meantime, a wood laminated wood laminated with wood-only lamina was obtained. The adhesive used was a water-soluble polymer-isocyanate adhesive (manufactured by Oshika Corporation, PI Bond 5300L) (coating amount 250 g / m ² ) and a room temperature press (press pressure 0.8 MPa), similar to the reinforcing lamina. , Press time 30 minutes). After bonding, the surface of the laminated wood was subjected to a moulder finish to obtain a wood laminated wood having a cross-sectional size of 120 mm × 240 mm and a length of 5,000 mm. A schematic cross-sectional view of this wood laminated wood is shown in FIG. Table 1 shows the evaluation results of this wood laminated wood.

The obtained wood laminated wood was cut in half at the center in the length direction, and the cross sections were joined by prestress in contact with each other. Prestress is made by inserting one PC steel rod with a diameter of 9 mm through an iron washer with a thickness of 120 mm x 240 mm and a thickness of 20 mm so as to cover the four tubular reinforcing members at the end of the wood laminated wood. It was passed through a reinforcing material (Fig. 4). A tension of 55 kN was applied to each PC steel rod and fixed with a nut so as not to loosen to obtain a wooden building material. Table 1 shows the evaluation results of this wooden building material.

(Example 2)
An iron washer having a thickness of 120 mm × 240 mm and a thickness of 20 mm was also sandwiched between the joint surfaces of the wood laminated wood cut in half in Example 1 (FIG. 5), and the diameter of the PC steel rod was changed to 13 mm to apply tension to the PC steel rod 1 For the book, a wooden building material was obtained in the same manner as in Example 1 except that the value was 110 kN. The evaluation results are shown in Table 1.

(Comparative Example 1)
It was the same as in Example 1 except that the tubular reinforcing material was not used in Example 1. FIG. 2 shows a schematic cross-sectional view of this wood laminated wood. Repeated bending test for evaluation could not be carried out because cracking occurred at the end of the wood laminated wood when a tension of 24 kN was applied.

(Comparative Example 2)
An existing wood laminated wood (E65-F225) having the same cross-sectional size of 120 mm × 240 mm and a length of 5,000 mm as in Example 1 was used. Similar to Example 1, the pieces were cut in half at the center in the length direction, and the cross sections were joined in contact with each other. As the joining method, the existing glue-in rod method was used. A wood laminated wood that joins four all-screw bolts with a diameter of 16 mm and a length of 600 mm was inserted at positions 40 mm from the four corners of the joint cross section so as to be 300 mm on the left and right, and filled with epoxy resin. After the curing period, it took two weeks to start the test. Table 1 shows the evaluation results of the joint test piece obtained by the glue-in rod method of the existing wood laminated wood.

The wood building material of the present invention can be applied to applications in which wood and laminated wood are used. Among them, it can be suitably used as a long frame material for large buildings such as schools, gymnasiums, auditoriums, various indoor ballparks and dome, and as a beam for buildings such as apartment houses and detached houses.

11 Rectangular hollow tubular reinforcing material 12 Wood laminated wood 21 Hollow part (without reinforcing material)
22 Wood laminated wood 31 Rod insertion part 32 Wood laminated wood 41 Wood laminated wood 42 Seat metal 43 Nut 44 PC steel rod 51 Wood laminated wood 52 Seat metal 53 Nut 54 PC steel rod 55 Indented reinforcement 61 Wood laminated wood 62 All screw bolts

Claims (12)

It is a wood building material in which at least two wood glulams are joined in the longitudinal direction, and the wood glulam is reinforced by a tubular reinforcing material penetrating in the longitudinal direction, and at least two wood glulams are contained in the tube reinforcing material. A wooden building material in which a tension material is provided that penetrates the inside of the tubular reinforcing material in the longitudinal direction, and the tension material is tensioned so that at least two wood laminated woods are fixed in a state of being joined in the longitudinal direction. .. The wood building material according to claim 1, wherein at least two wood laminated materials are joined via a recessed reinforcing material provided at the joint portion between the two. The wooden building material according to claim 1 or 2, which is used as a beam of a building. The wood-based building material according to any one of claims 1 to 3, wherein the tubular reinforcing material has a rectangular hollow cross section. The wood-based building material according to any one of claims 1 to 4, wherein the tubular reinforcing material has reinforcing fibers oriented in the longitudinal direction and fixed with a cured product of a thermosetting resin. The wood building material according to any one of claims 1 to 5, wherein the reinforcing fiber is a continuous fiber. The wood building material according to any one of claims 1 to 6, wherein the reinforcing fiber is carbon fiber, glass fiber or aromatic polyamide fiber. The wood-based building material according to any one of claims 1 to 7, wherein the tubular reinforcing material and the wood-based material piece are adhered in a direction in which the fiber directions of the wood-based laminated wood are parallel to each other. The wood-based building material according to any one of claims 1 to 8, wherein a plurality of tubular reinforcing materials are arranged at equidistant positions from the center of a cross section orthogonal to the longitudinal direction of the laminated wood. The wood building material according to any one of claims 1 to 9, wherein a tension of 10 to 300 kN is applied to the tension material. The woody building material according to any one of claims 2 to 10, wherein the embedded reinforcing material is made of a fiber reinforcing resin reinforced with carbon fiber, glass fiber or aromatic polyamide fiber, a metal or an inorganic material. In the wood building material according to claim 9, at least two of the tubular reinforcing materials arranged at equal distances from the center of the cross section orthogonal to the longitudinal direction of the wood laminated wood are provided with tensioning materials penetrating each of them. The timber-based building material is a wooden building material that is provided at a position that is point-symmetrical with respect to the center of the cross section orthogonal to the longitudinal direction of the wood-glulam.

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