Structural element, building, method for providing building, and use of structural element

Abstract

The invention relates to a structural element (1) for use as an outer surface of a building (2). The structural element (1) comprises a first layer (11) comprising wood material, a second layer (12) comprising wood material, and an insulating layer (13) consisting of an insulation material comprising cellulosic material. The insulating layer (13) is arranged between the first layer (11) and the second layer (12). The invention relates also to a building (2) utilizing the structural element (1). The invention relates also to a method for providing a building (2). The invention relates also to use of the structural element (1) as an outer surface of a building (2). The invention relates also to use of the structural element (1) as a load-bearing structure of a building (2).

Description

[0001] STRUCTURAL ELEMENT, BUILDING, METHOD FOR PROVIDING BUILDING, AND USE OF STRUCTURAL ELEMENT FIELD OF THE INVENTION

[0002] The present invention relates to a structural element and more particularly to a structural element comprising an insulation layer. The present invention further concerns a building, a method for providing a building, the use of the structural element as an outer surface of a building, and the use of the structural element as a load-bearing structure of a building.

[0003] BACKGROUND OF THE INVENTION

[0004] Sandwich elements comprising for example mineral wool between two layers of concrete can be used as an outer layer of a building.

[0005] A problem with such sandwich elements is the relatively high weight, which causes limitations in transporting and installing the elements. Another problem is that the heat conductivity of concrete is quite high, requiring the element to have relatively more mineral wool as a heat insulator in order to achieve the desired insulation ability. Still another problem is that the materials, especially concrete and mineral wool, are difficult to recycle. Still another problem is that the environmental impact of such elements determined as their total global warming potential (GWP Total) values is relatively high. GWP Total value is the sum of CO2equivalent emissions of a product.

[0006] BRIEF DESCRIPTION OF THE INVENTION

[0007] An object of the present invention is to provide a structural element to overcome above problems.

[0008] Another object of the present invention is to provide a building utilizing the structural element.

[0009] Another obj ect of the present invention is to provide a method for providing a building utilizing the structural element.

[0010] Yet another object of the present invention is to provide a use of the structural element as an outer surface of a building.Yet another object of the present invention is to provide a use of the structural element as a load-bearing structure of a building.

[0011] The objects of the invention are achieved by the structural element, the building, the method and the uses which are characterized by what is stated in the independent claims. The preferred embodiments of the invention are disclosed in the dependent claims.

[0012] The invention is based on the idea of providing a structural element for use as an outer surface of a building, wherein

[0013] the structural element comprises

[0014] a first layer having an inner surface and an outer surface opposite the inner surface, wherein the first layer comprises wood material at least 75 % by weight of the first layer,

[0015] a second layer having an inner surface and an outer surface opposite the inner surface, wherein the second layer comprises wood material at least 75 % by weight of the second layer, and

[0016] - an insulating layer consisting of an insulation material and having an inner surface and an outer surface opposite the inner surface, wherein the insulation material comprises cellulosic material at least 75 % by weight of the insulation material,

[0017] the insulating layer is arranged between the first layer and the second layer,

[0018] the inner surface of the insulating layer is bound to the outer surface of the first layer,

[0019] the outer surface of the insulating layer is bound to the inner surface of the second layer, and

[0020] the insulating layer is arranged to support at least one of the first layer and the second layer; and

[0021] The structural element has a heat transfer coefficient between the inner surface of the first layer and the outer surface of the second layer of at most 0.6 W / (m2·K).The invention is also based on the idea of providing a building comprising a loadbearing structure, and a structural element as described above attached to the loadbearing structure.

[0022] The invention is also based on the idea of providing a building comprising a loadbearing structure, wherein the load-bearing structure comprises a structural element as described above.

[0023] The invention is also based on the idea of providing a method for providing a building, wherein the method comprises

[0024] providing a load-bearing structure of the building, the load-bearing structure comprising steel or concrete,

[0025] providing a structural element as described above, and

[0026] attaching the structural element to the load-bearing structure.

[0027] The invention is also based on the idea of providing a method for providing a building, wherein

[0028] the method comprises providing a load-bearing structure; and

[0029] - the load-bearing structure comprises a structural element as described above. The invention is also based on the idea of using the structural element as described above as an outer surface of a building.

[0030] The invention is also based on the idea of using the structural element as described above as a load-bearing structure of a building.

[0031] An advantage of the invention is that the structural element of the invention is lighter than corresponding element containing concrete. The structural element has also a smaller heat conductivity than a corresponding element containing concrete. This allows larger number of elements to be transported in the same load without exceeding the maximum capacity of the transport vehicle. Lighter elements allow the use of lighter lifting equipment at the construction site.

[0032] The GWP Total value for the structural element is also lower than for corresponding elements containing concrete.BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The invention is described in detail with reference to the enclosed drawings, in which Figure 1 is a schematic cross-sectional side view of a structural element according to some embodiments of the invention;

[0034] Figure 2 is a schematic cross-sectional side view of a building according to some embodiments of the invention; and

[0035] Figure 3 is a schematic cross-sectional side view of a building according to some embodiments of the invention.

[0036] DETAILED DESCRIPTION OF THE INVENTION

[0037] In this context, term "wood material” means material consisting of cells composed of microfibrils of cellulose and hemicellulose impregnated with lignin.

[0038] In this context, term "cellulosic material” means material containing predominantly, such as at least 75 % by weight, cellulose fibres.

[0039] The invention relates to a structural element 1. The structural element 1 is a sandwiched structural element.

[0040] For example, the structural element 1 is suitable for use as an outer surface of a building 2. In other words, the structural element 1 is made of materials that are able to withstand the conditions required from materials used in outer surfaces of buildings. Preferably, the outer surface of the building 2 is a vertical wall of the building 2.

[0041] Preferably, the structural element 1 is also suitable for as the main heat insulating structure of a wall of the building 2. This means that the structural element 1 provides most of the heat insulating properties of the corresponding wall of the building 2. Preferably, the structural element 1 is also suitable for as a load-bearing structure of a building 2. In other words, the structural element 1 is suitable to carry at least a part of the load caused by parts of the building 2 above the structural element 1. Preferably, the building 2 is a single-storey building or a two-storey building. Preferably, the building 2 has a height of at most 14 m, more preferably 9 m. Preferably, the building 2 has a gross floor area of at most 2400 m2, preferably1600 m2. Preferably, the building 2 fulfils the requirements of a fire resistance class of P3 as defined in the National Building Code of Finland - Decree of the Ministry of the Environment on fire safety of buildings, adopted on 12.03.2002.

[0042]

[0043] The structural element 1 comprises a first layer 11. The first layer 11 has an inner surface 111 and an outer surface 112 opposite the inner surface 111. Preferably, the first layer 11 is used to form an inner wall of the building 2.

[0044] The first layer 11 comprises wood material at least 75 %, such as at least 90 %, by weight of the first layer 11. Using wood material in the first layer 11 makes the structural element 1 more environmentally friendly, lighter and less heat conductive than using, e.g. concrete. Wood material in the first layer 11 provides the structural element 1 with a better score in the life cycle analysis of the structural element 1 through a better GWP Total value. GWP Total value is the sum of CO2equivalent emissions of a product.

[0045] For example, the first layer 11 is wood panel, cross-laminated timber (CLT) panel, laminated veneer lumber (LVL) panel, plywood, medium density fibreboard (MDF), oriented strand board (OSB), or particle board.

[0046] For example, the first layer 11 has a thickness of 3 to 300 mm, preferably 15 to 240 mm, such as 30 to 120 mm. The thickness is determined between the inner surface 111 and the outer surface 112 of the first layer 11.

[0047] According to some embodiments, the inner surface 111 of the first layer 11 has been treated with a fireproofing treatment. The purpose of the fireproofing treatment is to improve the fire resistance of the structural element 1 to fulfil local fire safety standards.

[0048] Second layer

[0049] The structural element 1 comprises a second layer 12. The second layer has an inner surface 121 and an outer surface 122 opposite the inner surface 121. Preferably, the second layer 12 is used to form an outer wall of the building 2.

[0050] The second layer 12 comprises wood material at least 75 %, such as at least 90 %, by weight of the second layer 12. Using wood material in the second layer 12 makes thestructural element 1 more environmentally friendly, lighter and less heat conductive than using, e.g. concrete or steel. Wood material in the second layer 12 provides the structural element 1 with a better score in the life cycle analysis of the structural element 1 through a better GWP Total value.

[0051] For example, the second layer 12 is wood panel, cross-laminated timber (CLT) panel, laminated veneer lumber (LVL) panel, plywood, medium density fibreboard (MDF), oriented strand board (OSB), or particle board.

[0052] For example, the second layer 12 has a thickness of 3 to 120 mm, preferably 30 to 100 mm, such as 45 to 90 mm. The thickness is determined between the inner surface 121 and the outer surface 122 of the second layer 12.

[0053] According to some embodiments, the outer surface 122 of the second layer 12 has been treated with a weatherproofing treatment. The purpose of the weatherproofing treatment is to make the outer surface 122 of the second layer 12 more resistant to weather conditions and therefore more suitable to be used as an outer surface of a building 2. For example, the weatherproofing treatment is paint or lacquer.

[0054] According to some embodiments, the outer surface 122 of the second layer 12 has been treated with a fireproofing treatment. The purpose of the fireproofing treatment is to improve the fire resistance of the structural element 1 to fulfil local fire safety standards. The fireproofing treatment may also provide the outer surface 122 of the second layer 12 with weatherproofing properties.

[0055]

[0056] The structural element 1 comprises an insulating layer 13. The insulating layer 13 has an inner surface 131 and an outer surface 132 opposite the inner surface 131.

[0057] The insulating layer 13 is arranged between the first layer 11 and the second layer 12. In other words, the first layer 11, the insulating layer 13 and the second layer 12 form a sandwiched structure.

[0058] The inner surface 131 of the insulating layer 13 is bound to the outer surface 112 of the first layer 11. For example, the inner surface 131 of the insulating layer 13 is bound to the outer surface 112 of the first layer 11 by gluing.The outer surface 132 of the insulating layer 13 is bound to the inner surface 121 of the second layer 12. For example, the outer surface 132 of the insulating layer 13 is bound to the inner surface 121 of the second layer 12 by gluing.

[0059] The insulating layer 13 is arranged to support at least one of the first layer 11 and the second layer 12. In other words, the strength of the insulating layer 13 is sufficient to support the first layer 11, the second layer 12 or both the first layer 11 and the second layer 12. Correspondingly, the properties, such as the thickness and the material, of the first layer 11 and / or the second layer 12 have been selected in such a way that the insulating layer 13 is capable of supporting the first layer 11 and / or the second layer 12.

[0060] The insulating layer 13 consists of an insulation material. The insulation material comprises cellulosic material at least 75 %, such as 75 to 95 %, by weight of the insulation material. Preferably, the cellulosic material is wood-derived material. Preferably, the wood-derived material consists of a non-separated fibre fraction and a separated fibre fraction. In other words, the cellulosic material is a combination of a non-separated fibre fraction and a separated fibre fraction. For example, the nonseparated fibre fraction comprises wood material in particulate form. For example, the separated fibre fraction comprises wood-derived mechanical and / or chemical pulp.

[0061] For example, the insulation material comprises

[0062] wood-derived material as the separated fibre fraction 10 to 85 %, preferably 30 to 55 %, and more preferably 30 to 45 %, by weight of the insulation material, and

[0063] wood-derived material as the non-separated fibre fraction 10 to 85 %, preferably 40 to 60 %, and more preferably 50 to 60 %, by weight of the insulation material.

[0064] Preferably, the insulation material comprises fire retardant. For example, the insulation material comprises fire retardant 5 to 10 % by weight of the insulation material.For example, the insulation material is foam-formed insulation material. In other words, the insulation material is, for example, made by a foam-forming method. Therefore, the insulation material may comprise foaming agent in an amount of less than 1 %, such as 0.01 to 1 %, by weight of the insulation material.

[0065] An example of a material suitable as the insulation material has been disclosed in WO 2022 / 101550 Al.

[0066] For example, the insulating layer 13 has a thickness of 94 to 440 mm, preferably 110 to 400 mm, more preferably 165 to 330 mm such as 220 mm. The thickness is determined between the inner surface 131 and the outer surface 132 of the insulating layer 13.

[0067] According to some embodiments, the insulation material has a thermal conductivity of at most 0.10 W / m·K, preferably 0.025 to 0.10 W / m·K, more preferably 0.032 to 0.08 W / m·K, such as 0.036 to 0.05 W / m·K. This allows the insulation material to provide the structural element with sufficient heat insulation properties to be used as the main heat insulating structure of a wall of a building 2.

[0068] According to some embodiments, the insulation material has a density of 10 to 500 kg / m3, preferably 30 to 250 kg / m3, more preferably 40 to 150 kg / m3.

[0069] Properties of structural element

[0070] The structural element 1 has a heat transfer coefficient between the inner surface 111 of the first layer 11 and the outer surface 122 of the second layer 12 of at most 0.6 W / m2·K, preferably 0.05 to 0.6 W / m2·K, more preferably 0.10 to 0.3 W / m2·K. This allows the use of the structural element 1 as the main heat insulating structure of a wall of a building 2. The total heat transfer coefficient of the structural element 1 depends on the heat transfer coefficients of the first layer 11, the insulating layer 13 and the second layer 12, which in turn depend on the thickness and the thermal conductivity of the corresponding layer. For example, a smaller thickness of the first layer 11 or the second layer 12 can be compensated with a larger thickness of the insulating layer 13 in order to obtain the desired heat transfer coefficient of the structural element 1.For example, the structural element 1 has a thickness of 100 to 720 mm, preferably 270 to 540 mm.

[0071] The invention relates to a building 2. The building 2 comprises a load-bearing structure 21. The load-bearing structure 21 is arranged to bear the load of the building 2 above the load-bearing structure 21.

[0072] According to some first embodiments of the invention, the building 2 comprises a structural element 1 as described above. These embodiments are exemplified in Figure 2. The structural element 1 is attached to the load-bearing structure 21. The purpose of the structural element 1 is to act as an outer surface of the building 2. Preferably, the load-bearing structure 21 comprises steel or concrete. For example, the load bearing structure 21 is a column-beam frame, a column-slab frame or a loadbearing bookshelf frame. In the load-bearing bookshelf frame, transversal end walls, a longitudinal bulkhead and concrete slabs of the building bear a load of the building. Preferably, the building 2 is a multi-storey building.

[0073] According to some second embodiments of the invention, the load-bearing structure 21 comprises a structural element 1 as described above. These embodiments are exemplified in Figure 3. In other words, the structural element 1 forms a part of the load-bearing structure 21. Preferably, the building 2 is a single-storey building or a two-storey building. Preferably, the building 2 has a height of at most 14 m, more preferably 9 m. Preferably, the building 2 has a gross floor area of at most 2400 m2, preferably 1600 m2. Preferably, the building 2 fulfils the requirements of a fire resistance class of P3 as defined in the National Building Code of Finland - Decree of the Ministry of the Environment on fire safety of buildings, adopted on 12.03.2002.

[0074] Method

[0075] The invention relates to a method for providing a building 2. The method comprises providing a load-bearing structure 21 of the building 2. The load-bearing structure 21 is arranged to bear the load of the building 2 above the load-bearing structure 21. According to some first embodiments of the invention, the method comprises providing a structural element 1 as described above. In these embodiments, the method comprises attaching the structural element 1 to the load-bearing structure21. The purpose of the structural element 1 is to act as an outer surface of the building 2. Preferably, the building 2 is a multi-storey building. Preferably, the load-bearing structure 21 comprises steel or concrete. For example, the load bearing structure 21 is a column-beam frame, a column-slab frame or a load-bearing bookshelf frame. According to some further embodiments, attaching the structural element 1 to the load-bearing structure 2 comprises attaching the first layer 11, such as the inner surface 111 of the first layer 11, of the structural element 1 to the load bearing structure 2.

[0076] According to some further embodiments, attaching the structural element 1 to the load-bearing structure 2 comprises attaching the insulating layer 13 of the structural element 1 to the load bearing structure 2.

[0077] According to some second embodiments, the load-bearing structure 21 comprises a structural element 1 as described above. In other words, the structural element 1 forms a part of the load-bearing structure 21. Preferably, the building 2 is a singlestorey building or a two-storey building. Preferably, the building 2 has a height of at most 14 m, more preferably 9 m. Preferably, the building 2 has a gross floor area of at most 2400 m2, preferably 1600 m2. Preferably, the building 2 fulfils the requirements of a fire resistance class of P3 as defined in the National Building Code of Finland -Decree of the Ministry of the Environment on fire safety of buildings, adopted on 12.03.2002.

[0078] Use

[0079] The invention relates to the use of a structural element 1 as described above as an outer surface of a building 2. The structural element 1 is made of materials that are able to withstand the conditions required from materials used in outer surfaces of buildings. Preferably, the outer surface of the building 2 is a vertical wall of the building 2.

[0080] The invention relates to the use of a structural element 1 as described above as a loadbearing structure of a building 2. In other words, the structural element 1 is used to bear at least a part of the load caused by the building 2 above the structural element 1. Preferably, the building 2 is a single-storey building or a two-storey building. Preferably, the building 2 has a height of at most 14 m, more preferably 9 m.Preferably, the building 2 has a gross floor area of at most 2400 m2, preferably 1600 m2. Preferably, the building 2 fulfils the requirements of a fire resistance class of P3 as defined in the National Building Code of Finland - Decree of the Ministry of the Environment on fire safety of buildings, adopted on 12.03.2002.

[0081] The invention has been described above with reference to the examples shown in the figures. However, the invention is in no way restricted to the above examples but may vary within the scope of the claims.

Claims

CLAIMS1. A structural element (1) for use as an outer surface of a building (2), cha ra cte r i z e d in thatthe structural element (1) comprisesa first layer (11) having an inner surface (111) and an outer surface (112) opposite the inner surface (111), wherein the first layer (11) comprises wood material at least 75 % by weight of the first layer (11),a second layer (12) having an inner surface (121) and an outer surface (122) opposite the inner surface (121), wherein the second layer (12) comprises wood material at least 75 % by weight of the second layer (12), andan insulating layer (13) consisting of an insulation material and having an inner surface (131) and an outer surface (132) opposite the inner surface (131), whereinthe insulation material comprises cellulosic material at least 75 % by weight of the insulation material,the insulating layer (13) is arranged between the first layer (11) and the second layer (12),the inner surface (131) of the insulating layer (13) is bound to the outer surface (112) of the first layer (11),the outer surface (132) of the insulating layer (13) is bound to the inner surface (121) of the second layer (12), andthe insulating layer (13) is arranged to support at least one of the first layer (11) and the second layer (12); andthe structural element (1) has a heat transfer coefficient between the inner surface (111) of the first layer (11) and the outer surface (122) of the second layer (12) of at most 0.6 W / (m2-K).

2. The structural element (1) according to claim 1, c h a r a c t e r i z e d in that the heat transfer coefficient of the structural element (1) between the inner surface (111) of the first layer (11) and the outer surface (122) of the second layer (12) is 0.05 to 0.6 W / (m2-K), preferably 0.10 to 0.3 W / (m2-K).

3. The structural element (1) according to claim 1 or 2, c h a r a c t e r i z e d in that the insulation material has a thermal conductivity of at most 0.10 W / (m-K), preferably 0.025 to 0.10 W / (m-K), more preferably 0.032 to 0.08 W / (m-K), such as 0.036 to 0.05 W / (m-K).

4. The structural element (1) according to any one of the preceding claims, c h a r a c t e r i z e d in that the insulation material has a density of 10 to 500 kg / m3, preferably 30 to 250 kg / m3, more preferably 40 to 150 kg / m3.

5. The structural element (1) according to any one of the preceding claims, c h a r a c t e r i z e d in that the insulation material is foam-formed insulation material.

6. The structural element (1) according to any one of the preceding claims, c h a r a c t e r i z e d in that the wood material of the first layer (11) is wood panel, cross-laminated timber (CLT) panel, laminated veneer lumber (LVL) panel, plywood, medium density fibreboard (MDF), oriented strand board (OSB), or particle board.

7. The structural element (1) according to any one of the preceding claims, c h a r a c t e r i z e d in that the wood material of the second layer (12) is wood panel, cross-laminated timber (CLT) panel, laminated veneer lumber (LVL) panel, plywood, medium density fibreboard (MDF), oriented strand board (OSB), or particle board.

8. The structural element (1) according to any one of the preceding claims, c h a r a c t e r i z e d in that the outer surface (122) of the second layer (12) has been treated with a weatherproofing treatment, such as paint or lacquer.

9. The structural element (1) according to any one of the preceding claims, c h a r a c t e r i z e d in that the outer surface (122) of the second layer (12) has been treated with a fireproofing treatment.

10. A building (2), c h a r a c t e r i z e d in that the building (2) comprisesa load-bearing structure (21), anda structural element (1) according to any one of claims 1 to 9 attached to the load-bearing structure (21).

11. A building (2), c h a r a c t e r i z e d in thatthe building (2) comprises a load-bearing structure (21); andthe load-bearing structure (21) comprises a structural element (1) according to any one of claims 1 to 9.

12. A method for providing a building (2), c h a r a c t e r i z e d in that the method comprisesproviding a load-bearing structure (21),providing a structural element (1) according to any one of claims 1 to 9, andattaching the structural element (1) to the load-bearing structure (21).

13. A method for providing a building (2), c h a r a c t e r i z e d in thatthe method comprises providing a load-bearing structure (21); and the load-bearing structure (21) comprises a structural element (1) according to any one of claims 1 to 9.surface of a building (2).

15. Use of a structural element (1) according to any one of claims 1 to 9 as a loadbearing structure of a building (2).

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