JP4882392B2 - Construction materials - Google Patents

Description

  The present invention relates to a pillar material, a beam material, and other structural materials for building made of laminated material of different tree species in which lamina of different tree species are laminated.

  In recent years, a laminated material obtained by laminating and laminating a plurality of laminaes (grind boards) has been widely used as a structural material such as a pillar material or a beam material in a wooden building. Glulam can freely produce products with a larger cross-section and length than solid lumber, and the defects of wood are removed or dispersed during the manufacturing stage, so that warpage and cracking are less likely to occur, and dimensional stability And it has the feature of being excellent in homogeneity.

  Glulams are broadly divided into structural glulams used as pillars and beams and construction glulams used for sills, long presses, joinery frames, etc. Because a high strength is required, detailed performance standards are stipulated in Japanese Agricultural and Forestry Standards. For this reason, most of the tree species that are practically used as the lamina for structural laminated lumber are spruce and bay pine, and as a result, structural laminated lumber is more expensive than solid lumber. There was a trend.

  Therefore, in order to supply structural laminated timber at a low cost, it has been considered to mix domestic timber such as cedar, which has abundant domestic plantation forest resources, into laminated lamina. For example, in the “Development Project for Hybrid Timber Manufacturing System” (business entity: National Woodworking Machinery Manufacturers Association, National Wooden Housing Machinery Pre-Cut Association), a subsidized project of the Forestry Agency conducted from 1998 to 2012 The production technology of the laminated wood for heterogeneous tree structure that improved the bending performance by mixing cedar short timber and bay pine was studied, and the result was approved by the Japanese Agricultural Standard.

For example, as described in Patent Document 1, such a heterogeneous seed-gathered lumber is arranged with a lamina such as bay pine or duffeled larch in the outer layer (a position far from the neutral axis), which is considered to be high in strength. The cedar that is considered to be weak is arranged and laminated in the inner layer (near the neutral axis). This system of mixing different species of lamina contributes to revitalizing domestic plantation resources by actively utilizing domestic timber and other domestic timber, thereby increasing the absorption rate of carbon dioxide in the atmosphere. It is said that it is a meaningful technology even in national environmental problems.
JP 2000-153508 A

  As described above, the laminated material in which the outer layer and the inner layer are made of different species of lamina has a substantially uniform cross-sectional performance over the length direction (axial direction). However, in a structural material for a building that is actually used as a column member or a beam member, the strength performance required for the end portion and the intermediate portion in the material length direction is usually different. From this point of view, the present invention was made to further improve the strength design of the laminated wood according to the way the structural material for construction is used, and more rationalized the way of combining the tree species as a different tree species laminated wood. We propose a structural material for building and promote effective utilization of low-strength tree species such as cedar.

In order to achieve the above-mentioned object, the structural material for building of the present invention is a columnar material, a beam material, or a substantially rod-shaped structural material for building made of different tree species laminated with different types of lamina. It is characterized in that the tree species composition relating to the strength of the lamina is made different between the both end portions and the intermediate portion.

That is, the present invention is characterized in that the tree species configuration of both ends and the middle portion in the material length direction is different from that in which the tree species configuration of the outer layer and the inner layer is different as in the above-described conventional different tree species laminated lumber. Have As a result, the possibility of rational strength design according to the stress distribution when used as a column material or a beam material is expanded, and the low strength material can be effectively utilized.

As a specific configuration of the invention, both ends in the wood length direction are laminated with lamina of high-strength tree species, and the middle portion in the wood length direction is laminated with lamina of low-strength tree species, or with lamina of low-strength tree species. -Laminate of high-strength tree species can be mixed and laminated. This configuration assumes a structural material having a relatively large cross-sectional area. This type of structural material often has both ends joined to other structural materials via various types of joint hardware, and the joint is expected to have a strength close to a rigid joint. Therefore, holes for inserting bolts and drift pins and slits for inserting plates are processed at the end, and bending stress, tensile stress, and shear stress are concentrated in the vicinity of these processed portions. Therefore, in order to ensure the proof strength of the end portion, the lamina configuration of the high-strength tree species from the outer layer to the inner layer, while the lamina configuration mainly composed of the low-strength tree species for the intermediate portion where the stress is not concentrated much, Reasonable and economical distribution of tree species.

Also, as the opposite configuration, both ends in the lumber direction are laminated with lamina of low-strength tree species, or laminating lamina of low-strength tree species and lamina of medium / high-strength tree layers, The middle part may be a laminate of high-strength tree lamina. This configuration assumes a structural material having a relatively small cross-sectional area. This type of structural material is mainly used mainly in the conventional frame construction method, but both ends thereof are often joined to other structural materials by mortise processing or the like. Such joints are originally not expected to have very high joint strength, but stress is caused by bending in the middle part of the elongated material. For example, in the case of column materials, the strength design is such that the middle part does not easily buckle. Is required. Therefore, the middle part has a lamina composition of high-strength tree species from the outer layer to the inner layer, while the end part that does not expect large joint strength has a lamina composition mainly composed of low-strength tree species, and the tree species that is rational and economical as a whole Allocation is realized.

  Furthermore, in the case where an outer wall material, a structural plywood or other surface material strength element as the base material is attached to at least one surface of the structural material for building, the surface material strength element of the surface to be joined is attached. By making the outer layer a lamina of a high-strength tree species, it is possible to ensure the pulling-out strength and shearing strength of joints such as screws and nails.

  In the present invention, as the intensity classification of the tree species, high-intensity tree species such as bay pine, dafrika larch, cypress, hiba, larch, etc. Are assumed to be Japanese cedar (Japanese cedar, Japanese cedar, etc.). However, since there are individual differences in the strength of the timber itself, the above classification is only a guideline, and the main part of the present invention is the strength of the tree species stacked between the end portion and the middle portion of one piece of wood. Are “relatively” different.

  The building structural material of the present invention configured as described above assumes a stress distribution in the material length direction when used as a pillar material or a beam material, and the portion where strength is required is a lamina of a high strength tree species. On the other hand, the laminar structure mainly composed of low-strength tree species is used for the parts where stress is not concentrated very much, so that the tree species can be distributed rationally and economically as a whole. However, it is possible to effectively use low-strength tree species such as domestic cedar.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  A structural material 1A for building illustrated in FIG. 1 is a large-section pillar material used for an industrialized house or the like. The material length is for one layer, and the cross section is 12 to 15 cm square. In this column material, slits 2 and bolt holes 3 for connecting appropriate metal fittings (not shown) to the column base and the column head are processed. Since local bending stress, tensile stress, and shear stress are generated at this processing location, both end portions 4 within several tens of centimeters are formed by laminating lamina made of high-strength tree species such as pine. Has been. On the other hand, the intermediate portion 5 indicated by halftone dots in the figure is mainly composed of lamina made of low-intensity tree species such as cedar. Known finger joints and skirt joints are used at locations where the laminas are joined in the length direction. The practical material length ratio between the end portions 4 made of high-strength tree species and the intermediate portion 5 made of low-strength tree species is approximately 2: 8 to 3: 7.

  The structural material for building 1B illustrated in FIG. 2 is a modified form in the case where the pillar material of FIG. 1 is arranged on the outer peripheral portion of the building. This column member is attached to one side surface (the left front side in the figure) with an outer wall body and other surface material load-bearing elements (not shown) with screws or nails. Therefore, the outer layer 6 on one side is formed of a high-strength tree species lamina over the entire length of the material so as to ensure the pulling strength and shearing strength of these joints and to sufficiently exhibit the strength as a bearing wall.

  The structural material 1C for building illustrated in FIG. 3 is a column member having a medium cross section that is used in a conventional frame construction method. The material length is for one layer, and the cross section is 9 to 12 cm square. In this column material, the column base and the column head are tenoned to the base and the beam material. Although the joint strength by the tenon 7 is not originally expected to have a very large joint strength, the intermediate portion 8 is required to have a strength that does not easily buckle. Therefore, both end portions 9 within a few tens of centimeters indicated by halftone dots in the figure have a lamina structure composed of low-strength tree species such as cedar and the intermediate portion 8 is a lamina composed of high-strength tree species such as bay pine from the outer layer to the inner layer. It is configured.

  The construction structural material 1D illustrated in FIG. 4 is a modified form in the case where the pillar material of FIG. 3 is arranged on the outer peripheral portion of the building. This column member is attached to one side surface (the left front side in the figure) with an outer wall body and other surface material load-bearing elements (not shown) with screws or nails. Therefore. The outer layer 10 on one side is formed of a lamina of high-strength tree species over the entire length of the material so that the pulling strength and shear strength of these joints can be secured and the strength as a load bearing wall can be sufficiently exhibited.

  The construction structural material 1E illustrated in FIG. 5 is a large-section beam material used for an industrialized house or the like. The material length is several meters, and the cross section is about 15 cm wide × 30 cm high. The beam material is processed with slits 11 and bolt holes 12 for connecting appropriate metal fittings (not shown) at both ends. Since local bending stress, tensile stress, and shear stress are generated in this processed portion, both end portions 13 within several tens of centimeters are formed by laminating lamina made of high-strength tree species such as bay pine. ing. The intermediate portion 14 has a sandwich structure in which an inner layer 15 (a halftone dot portion in the figure) mainly composed of a lamina composed of low-strength tree species such as cedar is sandwiched from above and below by a lamina outer layer 16 composed of a high-strength tree species. Yes. Known finger joints and skirt joints are employed at locations where the laminaes are joined in the material length direction.

  In this way, the structural material for building of the present invention assumes the stress distribution in the material length direction when used as a pillar material or a beam material, and the portion where strength is required is a lamina configuration of a high-strength tree species. On the other hand, the intermediate part where stress is not concentrated is a laminar structure mainly composed of low-strength tree species. As a result, it is possible to achieve a reasonable and economical tree species distribution as a whole while ensuring the necessary strength, and to promote the use of low-strength tree species such as cedar.

It is a perspective view of the pillar material concerning a 1st embodiment of the present invention. It is a perspective view of the pillar material concerning a 2nd embodiment of the present invention. It is a perspective view of the pillar material concerning a 3rd embodiment of the present invention. It is a perspective view of the pillar material which concerns on 4th Embodiment of this invention. It is a perspective view of the beam material which concerns on 5th Embodiment of this invention.

Explanation of symbols

1A, 1B, 1C, 1D, 1E, structural material for building 4 end 5 intermediate portion 8 intermediate portion 9 end portion 10 outer layer 13 end portion 14 intermediate portion 15 inner layer 16 outer layer

Claims (5)

In columnar materials, beam materials, and other substantially rod-shaped building structural materials made of laminated different types of lamina of different tree species, the tree species composition related to the strength of the lamina is made different at both ends and the middle in the material length direction. A structural material for construction characterized by that. Laminates of high-strength tree species are laminated at both ends in the wood length direction, and lamina of low-strength tree species is laminated at the middle portion in the wood length direction, or lamina of low-strength tree species and lamina of medium- and high-strength tree species are mixed and laminated. The structural material for building according to claim 1, wherein:   The structural material for building according to claim 2, wherein an outer layer of a surface to which the face material strength elements are joined is composed of lamina of high strength tree species. Laminates of low-strength tree species are laminated at both ends in the wood length direction, or lamina of low-strength tree species and lamina of medium- and high-strength tree species are laminated, and laminaes of high-strength tree species are laminated at the middle portion in the wood length direction. The structural material for building according to claim 1, wherein:   The building structural material according to claim 4, wherein an outer layer of a surface to which the face material strength elements are joined is composed of a lamina of a high-strength tree species.

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