JP2024150860A - Wooden curtain wall exterior wall material, wooden curtain wall structure, manufacturing method for wooden curtain wall exterior wall material - Google Patents

Abstract

[Problem] To use wood materials as the exterior wall of a curtain wall, which reduces the environmental impact and also exhibits good flame retardancy or fire resistance. [Solution] The concrete layer 10, panel-shaped wood materials 20, and a heat insulating layer 30 interposed between the concrete layer 10 and the wood materials 20, are connected to each other by a connecting material 40 that penetrates the heat insulating layer 30. [Selected Figure] Figure 1

Description

The present invention relates to a curtain wall exterior material using wood materials, a curtain wall structure using wood materials, and a manufacturing method for a curtain wall exterior material using wood materials.

Curtain wall structures are widely used for the exterior walls of (high-rise) buildings.
A curtain wall is a wall that separates the interior and exterior spaces like a curtain, excluding load-bearing walls that do not support the load of the building itself, and has sufficient strength against external forces such as earthquakes and typhoons, and even if displacement occurs on the upper and lower floors, the exterior walls will follow without falling off or being damaged. Curtain wall materials or units are manufactured in a factory and attached to the building using mounting hardware called fasteners.

Examples of curtain wall exteriors include glass curtain walls, which are fully glass exterior walls, honeycomb aluminum panels, titanium panels, ceramic panels, and PCa (precast) curtain walls.

These materials generally have a large environmental impact.
The present inventors have focused on using wood materials for the exterior walls of curtain walls from the viewpoints of reducing the environmental load and making effective use of natural materials.

On the other hand, in recent years, attention has been focused on the use of wood materials, and there has been an increasing trend to use wood materials not only as they are but also as composite materials with other materials.
For example, there is a trend toward using CLT with increased strength. CLT is an abbreviation for Cross Laminated Timber, and is a type of wood material made by lining up planks (laminas) and then laminating and gluing them together so that the fiber directions are perpendicular to each other.

There are various known applications for CLT.
The present inventor proposed Patent Document 1 as prior art for using wooden materials such as CLT as the exterior wall of a curtain wall.

JP 2022-183726 A

The prior art has the idea of covering the exterior of CLT wood materials with a covering material, and seeks to use flame-retardant or fire-resistant concrete as the "exterior covering."

However, the prior art is insufficient in terms of flame retardancy or fire resistance, and the integrity of the "external covering portion" with the wood material is also insufficient.
Furthermore, while high design quality is often required for the exterior surface of curtain walls, it is difficult to create a uniform concrete surface, and it was found that there is room for improvement from this perspective.

Therefore, the main objective of the present invention is to provide a curtain wall exterior material structure using wood materials, a curtain wall exterior structure using wood materials, and a curtain wall exterior construction method using wood materials that use wooden materials as the exterior wall of a curtain wall, which not only reduces the environmental load but also exhibits good flame retardancy or fire resistance.

The following aspects are included as means for solving the above problems.
<First aspect>
A concrete layer;
Panel-shaped wood materials,
A heat insulating layer is interposed between the concrete layer and the wood material,
The concrete layer and the wood material are connected by a connecting material that penetrates the thermal insulation layer.
A curtain wall exterior material that uses wood materials.

<Second aspect>
A concrete layer;
Panel-shaped wood materials,
A heat insulating layer is interposed between the concrete layer and the wood part,
The concrete layer and the wood material are connected by a connecting material that penetrates the thermal insulation layer,
A fastener stud is embedded in the concrete layer, and a fastener connected to the stud is supported on a structural material of the building.
A curtain wall structure using wood materials.

<Third aspect>
A concrete layer;
Panel-shaped wood materials,
A heat insulating layer is interposed between the concrete layer and the wood material,
A method for manufacturing a wood-based curtain wall exterior wall material, in which the concrete layer and the wood material are connected by a connecting material that penetrates the thermal insulation layer,
A material constituting the concrete layer is poured into the formwork from above, and then the heat insulating layer and the wood material are placed in order upward.
A method for manufacturing a curtain wall exterior material using wood materials.

According to the present invention, wooden materials such as CLT can be used as the exterior wall of a curtain wall, which not only reduces the environmental impact but also exhibits good flame retardancy or fire resistance.

FIG. 2 is a partially cutaway perspective view from the outside of the room showing an example of a curtain wall structural material. This is a cross-sectional view taken along line 2-2. This is a cross-sectional view taken along line 3-3. This is a cross-sectional view taken along line 4-4. FIG. FIG. 2 is a partially cutaway perspective view from the outside of the room showing another example of a curtain wall structural material. This is a cross-sectional view taken along line 7-7. This is a cross-sectional view taken along line 8-8. FIG. 5 is a cross-sectional view corresponding to FIG. 4 for explaining a manufacturing method of a curtain wall exterior wall material. 1 is a graph of the temperature in a heating furnace for test specimen X. 1 is a graph showing the temperature of the inner surface of the concrete layer side of test specimen X. 1 is a graph showing the temperature of the inner surface of the CLT side for test specimen X. 1 is a graph of the internal temperature of the CLT for specimen Y. FIG. 11 is a cross-sectional view showing another example of a curtain wall exterior wall material. FIG. 11 is a cross-sectional view showing yet another example of a curtain wall exterior building material.

(Embodiment 1)
(Wood-based curtain wall exterior material)
1 to 5 show examples of exterior wall materials. However, as a curtain wall structure, fasteners for supporting the curtain wall exterior wall material against the structural members of the building are also shown.

The curtain wall exterior material of the embodiment has a concrete layer 10, panel-shaped wooden materials 20, and a heat insulating layer 30 interposed between the concrete layer 10 and the wooden materials 20, and the concrete layer 10 and the wooden materials 20 are connected by a connecting material 40 that penetrates the heat insulating layer 30.

The concrete layer 10 can be obtained by pouring concrete material into a panel shape. If necessary, reinforcing steel bars, reinforcing fiber materials, etc. may be mixed into the concrete layer 10.
Examples of fibers for fiber reinforced concrete include glass fibers (GRC), carbon fibers (CFRC), polypropylene resin fibers, steel fibers (SFRC), and stainless steel fibers.

The concrete layer 10 may be flat overall, or may have a protruding portion 11 on its outer periphery as shown in the example shown in the figure, with wood material 20 provided within the area surrounded by the protruding portion 11.
Forming the overhanging portion 11 on the outer periphery not only improves the strength of the outer periphery, but also makes it possible to attach a waterproofing material that exhibits waterproofing performance. The overhanging portion 11 also serves as a support for the load of the wooden material 20, and also exhibits the effect of preventing rainwater from entering from the end face of the wooden material 20.

On the other hand, in one embodiment, the concrete layer 10 may be formed with an intermediate protrusion 12 at the intermediate position in the height direction, as shown in the illustrated example.
Although not shown, a widthwise intermediate protrusion may be provided at the widthwise intermediate portion of the concrete layer 10 .
The intermediate vertical extension portion 12 can be utilized as an embedded portion for a fastener stud 50, and the fastener 52 connected to the stud 50 can be supported against a structural material of a building (not shown), for example, via a bracket (not shown).

In this type of example where an intermediate overhang portion 12 is provided, wood material 20 is provided in the area surrounded by overhang portion 11 and intermediate overhang portion 12.

As the wood material 20, it is optimal to use panel-shaped wood material (CLT) in which the grain directions are perpendicular to each other in terms of strength and bending resistance, but other wood materials such as veneer can also be used.
The wood material can be formed of a plate-like member made of wood or laminated wood. Laminated wood includes an oriented board formed by joining together a plurality of planar rectangular sawn boards (laminas) at their long sides. The number of lamina layers of the wood material is preferably 3 to 9. If there are 2 or fewer layers, sufficient strength cannot be obtained, and if there are 10 or more layers, the material tends to be too bulky and difficult to handle.
The thickness of the unit lamina is preferably 1 cm to 3.6 cm. If it is less than 1 cm, sufficient strength cannot be obtained, and if it exceeds 3.6 cm, it may become too bulky and difficult to handle.
If necessary, the wood material 20 can be made of wood impregnated with a fire retardant agent to further increase fire resistance.

In the embodiment, the concrete layer 10, wood material 20, and insulating layer 30 are formed in a rectangular shape, but other shapes such as a rectangle, circle, ellipse, or curved shape are not excluded.

The surfaces of the wood material 20 (the exterior side in contact with the concrete layer 10, the end faces in contact with the overhanging portion 11, and, if necessary, the exterior side as well) may be waterproofed to form a waterproofing treatment.

In this embodiment of the present invention, a heat insulating layer 30 is interposed between the concrete layer 10 and the wood material 20 .
The material for forming the heat insulating layer 30 may be one selected from the group consisting of gypsum board, calcium silicate board, and wood wool cement board, or a composite material. An example of a composite material is a laminate of boards made of these materials.
The heat insulating layer 30 is preferably made of a material called semi-fireproof or non-combustible material. As the flame retardant or fire resistant material, it is preferable that the material conforms to Article 107 of the Enforcement Order of the Building Standards Act.

Although concrete is fire-resistant and waterproof, it is heavy and emits a large amount of carbon during its production, so it is preferable to make the concrete layer 10 as thin as possible and use semi-fireproof materials to achieve the desired fire resistance.

A particularly suitable material for forming the heat insulating layer 30 is a wood wool cement board, which is inexpensive and uses wood that can store carbon from the viewpoint of environmental protection.
Wood wool cement boards are building boards made by shaving wood wool into ribbons, primarily from thinning materials, unused wood, and lumber residues, mixing it with cement, and compressing and molding it.
Its quality was measured by the establishment of provisional Japanese standards in the early Showa period, which form the basis of today's JIS standards.
In the 1940s, it was listed as a representative semi-fireproof material in the Ministry of Construction's Building Standards Act Enforcement Order, and many fire-resistant structures were also notified.
Wood wool cement boards have a wide range of performance capabilities, including fire resistance, insulation, sound absorption, soundproofing and moisture control, and the JIS standard clarifies performance and quality, classifying them into three types - ordinary wood wool cement boards, medium wood wool cement boards and hard wood wool cement boards - according to guidelines for application to appropriate locations.
The characteristics of this type and JIS standards are described in detail in the "Wood Cement Board Guidebook" (March 2011) published by the National Wood Cement Board Industry Association.
Wood wool cement boards have excellent moisture-regulating properties. If we were to use wood wool cement boards on the ceiling and walls of an eight-tatami room, they would absorb about 24 liters of moisture in 10 days and release that moisture when the room dries out, automatically regulating the humidity and creating a comfortable space.
Various types of gypsum boards and calcium silicate boards can be used. For example, reinforced gypsum boards are also useful.

By the way, the specific gravity of concrete is about 2.4 to 2.0, while that of wood wool cement board is about 0.5 to 0.6, that of gypsum board is about 0.7, and that of calcium silicate board is about 0.8.

The concrete layer 10 exhibits fire resistance. However, if one were to ensure sufficient fire resistance or non-combustibility with a panel configuration consisting only of the concrete layer 10 and the wooden members 20, a thickness of, for example, about 15 to 25 cm would be required as the exterior wall of a high-rise building.
The heat insulating layer 30 exemplified above is light in weight, having a specific gravity of about 1/2.5 to 1/5 compared to the concrete layer.
Providing a heat insulating layer 30 between the concrete layer 10 and the wood material 20 enhances fire resistance or non-combustibility.

However, the function of enhancing fire resistance or non-combustibility by the interposition of the insulating layer 30 means that it is possible to reduce the thickness of the concrete layer 10. Moreover, if the thickness of the concrete layer 10 is reduced and the combined thickness with the insulating layer 30 is made, for example, about 9.5 cm, the total weight of the concrete layer 10 and the insulating layer 30 will be reduced significantly due to specific gravity.
For example, the layer thickness is preferably in the following range.
Thickness of concrete layer 10: 8 cm to 10 cm
Thickness of the heat insulating layer 30: 1.0 cm to 2.5 cm
If the thickness of the concrete layer 10 is reduced, the load on the exterior wall will be reduced, leading to a significant reduction in the design load of the curtain wall structure.

In addition to its ability to enhance fire resistance or non-combustibility, wood wool cement boards are noted for their excellent moisture-regulating function, as mentioned above. This moisture-regulating function is particularly prominent in one example of a manufacturing method for curtain wall exterior material, which will be described later.

An insulating layer 30 is interposed between the concrete layer 10 and the wood material 20 , and the insulating layer 30 is connected by a connecting material 40 that penetrates the insulating layer 30 .
That is, while it may be difficult to ensure wind resistance with only the thin concrete layer 10, the wind resistance is improved by using a connected structure.

Although not limited to the connecting material 40 and the connecting structure, an example can be given in which a bolt 42 is screwed into an insert 41 embedded in the concrete layer 10, and the insert 41 is connected by a first nut 43 for fixing the insert to the concrete layer 10, and a second nut 44 for fixing the interior side of the wood material 20.
It is preferable to fill the gap between the outer periphery of the bolt 42 and the insertion hole of the wooden material 20 with non-shrink mortar (not shown), which will eliminate any play and increase the durability of the connection. Inorganic grout materials may be used instead of mortar.

Reference numeral 45 denotes an air vent hole, which is used to allow moisture and steam from the concrete material that may leak out in the event of a fire to escape to the outside when the concrete layer 10 is poured.
Furthermore, if sufficient gaps are secured around the four sides of the concrete layer 10 so that moisture and steam can escape to the outside, the air vent holes 45 are not necessary.

(Embodiment 2)
(Curtain wall structure)
The curtain wall structure of the embodiment includes a curtain wall exterior material having a concrete layer 10, panel-shaped wooden materials 20, and an insulating layer 30 interposed between the concrete layer 10 and the wooden materials 20, with the concrete layer 10 and the wooden materials 20 connected by connecting materials 40 that penetrate the insulating layer 30.
Fastener studs are embedded in the concrete layer 10 of the curtain wall exterior material, and fasteners connected to the studs are supported against the structural materials of the building.
In this way, even if the wooden material 20 burns due to a fire inside the building, the concrete layer 10 is supported and the possibility of it falling off can be eliminated.

In the embodiment, a fastener stud 50 is embedded in the projection portion 11, the intermediate projection portion in the width direction, or the intermediate projection portion in the height direction 12, and a fastener 52 is fixed to this stud 50, for example by welding, so that the fastener 52 can be supported against a structural material of a building not shown, for example via a support bracket (not shown).
For example, the fasteners 52 are connected by locking, welding, bolting, etc. to curtain wall support brackets fixed to, for example, steel beams or columns provided on the main body of a (high-rise) building, to construct the curtain wall exterior.
The number of fasteners 52 may be determined appropriately depending on the size of the exterior wall structure, etc.

The curtain wall exterior materials in the above example are arranged adjacent to each other to form a wide exterior wall, so a waterproof rubber sealant 60 can be attached to the adjacent sides in advance. This provides protection for the materials inside the exterior wall structural material against the intrusion of rainwater and against water being sprayed from outside in the event of a fire.

(Embodiment 3)
(Manufacturing method for curtain wall exterior material)
The manufacturing method of the curtain wall exterior building material of the embodiment includes a curtain wall exterior building material having a concrete layer 10, a panel-shaped wooden material 20, and an insulating layer 30 interposed between the concrete layer 10 and the wooden material 20, with the concrete layer 10 and the wooden material 20 connected by a connecting material 40 that penetrates the insulating layer 30.
As shown in the example of Figure 9, this curtain wall exterior material is manufactured by pouring the material that constitutes the concrete layer 10 into a formwork 70 from above, and after the concrete layer 10 has hardened, the insulating layer 30 and the wood material 20 are placed on top in that order.

In this case, the connecting material 40, studs 50, fasteners 52, and sealing material 60 can be placed at any time.

By adopting such a manufacturing method, it becomes easy to form the projections 11 and 12 and to embed the studs 50.
Another distinctive feature is that by making the inner surface of the formwork 70 smooth or, in some cases, forming decorative irregularities, the desired design can be reliably obtained on the outer surface of the concrete layer (exterior curtain wall) 10.

When a wood wool cement board is used as the heat insulating layer 30, even if the concrete layer 10 is heated by flames on the exterior wall side, the heat is slowly transmitted to the wood material 20 through the gaps in the wood wool cement board, so the temperature rise of the wood material 20 can be suppressed. In this sense, it is clear that the use of wood wool cement boards is effective, and it can be naturally expected that their effectiveness will be greater than that of gypsum boards or calcium silicate boards.

(Embodiment 4)
(Other examples of curtain wall exterior materials)
A suitable decorative material 80 may be secured to the exterior surface of the curtain wall exterior material.
For example, a wood-based decorative material can be used as this decorative material 80, which allows the wood to be seen from the outside, improves the aesthetic appearance of the exterior wall, and emphasizes that the building is made of materials with low environmental impact.

(Embodiment 5)
(Other examples of curtain wall exterior materials)
As described above, the concrete layer 10 may be planar without forming any overhanging portion, as shown in FIG. 14, for example.

(Embodiment 6)
(Other examples of curtain wall exterior materials)
15, a step may be provided on the outer periphery of the planar concrete layer 10A, a heat insulating layer 30 may be provided in the area surrounded by the step, and the outer periphery of the exterior wall material may be formed by the concrete layer 10A and the wood material 20. A sealant 60 may be provided on the outer periphery of the planar concrete layer 10A, if necessary.

In the above-mentioned embodiments 5 and 6, decorative materials can also be provided.

An experimental example is given.
(First Experiment)
A test specimen X having a size of 1200 mm x 1200 mm and a layer structure of 185 mm in total thickness, which is composed of a concrete layer having a thickness of 80 mm, an insulating layer of a 15 mm thick cemented wood board, and a wooden material having a thickness of 90 mm made of CLT, was placed in a heating furnace and heated according to the heating pattern shown in Figure 10.
For the test specimens, thermocouples numbered 1 to 5 and thermocouples numbered 6 to 10 were attached at approximately equal intervals (i.e., at the four corners and the center) inside the wood material on the RC side and the CLT side, respectively, to examine the temperature change over time.

As a result, as shown in Figures 11 and 12, the temperature rise of the RC surface continues to increase even after the temperature inside the heating furnace starts to decrease.
However, it was found that the temperature of the wood surface made of CLT maintained a temperature of approximately 100°C from approximately 30 minutes before the temperature inside the heating furnace began to drop (approximately 60 minutes after the start of the drop) until 90 minutes after the start of the drop, and then showed a gradual temperature rise after 90 minutes had passed.
This is presumably because the insulating layer of the wood wool cement board acts as a heat insulator while retaining moisture vapor from the concrete layer.

(Second Experiment)
For comparison, specimen Y (without a heat insulating layer) measuring 1200 mm x 1200 mm had a layered structure with a total thickness of 185 mm, consisting of an 80 mm thick concrete layer and 90 mm thick CLT wood material, with a gap of 15 mm between them and the concrete layer and wood material connected at multiple points by connecting bolts. It was placed in a heating furnace and heated in a pattern similar to that in Figure 10.
As a result, the internal temperature of the wooden material made of CLT at thermocouples 1 to 5 installed at the four corners and center inside the wooden material on the CLT side of test specimen Y continued to rise as heating progressed, as shown in Figure 13, and after about 100 minutes, the temperature had risen to over 260°C in some locations, and did not show the same temperature (change) behavior as test specimen X. Incidentally, about 260°C is the ignition temperature of ordinary wooden material made of CLT.

The wooden curtain wall exterior of the present invention takes advantage of the characteristics of wooden materials, such as lightness and ease of handling, while also having sufficient strength and fire resistance, so it is expected to be used as a structural material (fire-resistant wooden curtain wall) for wooden (high-rise) buildings.

10: concrete layer, 20: wood material, 30: heat insulating layer, 40: connecting material, 50: stud, 52: fastener, 60: sealing material, 70: formwork.

Claims (8)

A concrete layer;
Panel-shaped wood materials,
A heat insulating layer is interposed between the concrete layer and the wood material,
The concrete layer and the wood material are connected by a connecting material that penetrates the thermal insulation layer.
A curtain wall exterior material that uses wood materials. A concrete layer;
Panel-shaped wood materials,
A heat insulating layer is interposed between the concrete layer and the wood part,
The concrete layer and the wood material are connected by a connecting material that penetrates the thermal insulation layer,
A fastener stud is embedded in the concrete layer, and a fastener connected to the stud is supported on a structural material of the building.
A curtain wall structure using wood materials. The concrete layer has an overhang on its outer periphery, and the wood material is provided within the area surrounded by the overhang. The curtain wall structure using wood material according to claim 2. The concrete layer has a peripheral overhang portion on an outer periphery thereof and also has an intermediate overhang portion within an area surrounded by the peripheral overhang portion,
A fastener stud is embedded in the intermediate overhang, and a fastener connected to the stud is supported on a structural material of the building.
The wooden curtain wall structure according to claim 1. The wooden curtain wall structure according to claim 1, wherein the heat insulating layer is selected from the group consisting of gypsum board, calcium silicate board, and wood wool cement board. The wooden curtain wall structure according to claim 1, in which a decorative material is fixed to the outer surface of the concrete layer. A concrete layer;
Panel-shaped wood materials,
A heat insulating layer is interposed between the concrete layer and the wood material,
A method for manufacturing a wood-based curtain wall exterior wall material, in which the concrete layer and the wood material are connected by a connecting material that penetrates the thermal insulation layer,
A material constituting the concrete layer is poured into the formwork from above, and then the heat insulating layer and the wood material are placed in that order upward.
A method for manufacturing a curtain wall exterior material using wood materials. 2. A method for manufacturing a curtain wall exterior material using wood material as described in claim 1, wherein an insert is embedded in the concrete layer, a bolt connecting the insert is inserted through the insulating layer and the wood material, and then the bolt is fastened with a nut on the outer surface side of the wood material.

Images