JP7815562B2 - Wood-covered RC member and its forming method - Google Patents

Description

The present invention relates to wood-coated reinforced concrete members and methods for forming them.

Amid the recent growing demand for reducing environmental impacts and active efforts to be environmentally conscious, there has been active development of technologies in the construction industry that make effective use of wood materials. The main technologies that utilize these wood materials include the design and construction of wooden buildings.

By the way, there are buildings made of RC (Reinforced Concrete) and SRC (Steel Reinforced Concrete), which have greater strength and rigidity than wooden buildings, making it possible to build high-rise and super-tall buildings.

Therefore, there is a demand for building components that effectively utilize the above-mentioned wood materials while retaining the strength and rigidity of reinforced concrete members.

Patent Document 1 proposes a surface-finished wooden column manufactured by joining three or more long, rectangular wooden boards together to create a hollow column with a hollow space, placing rebar in the hollow space, and filling it with concrete, as well as a method for manufacturing such a column. In this manufacturing method, the hollow column formed from the wooden boards functions as a formwork when filled with concrete.

Japanese Patent Application Laid-Open No. 2021-67026

The surface wood column and manufacturing method described in Patent Document 1 make it possible to manufacture columns that have the strength and rigidity of reinforced concrete members while making effective use of wood materials. However, because hollow columns made from wooden boards are used as formwork and concrete is filled inside, there is a very high possibility that concrete will adhere to the surface of the wood material, causing stains. In order for the wood material to function as a design material that adds aesthetic appeal, post-processing is required to wash away any stains that have adhered to the surface. Alternatively, to prevent such stains from adhering, measures such as pre-curing the wood material to prevent concrete from adhering to it are necessary. In either case, some kind of stain prevention measure is required, posing a problem.

The present invention was made in consideration of the above-mentioned problems, and aims to provide a wood-coated RC member that eliminates the need for stain prevention measures and a method for forming the same.

In order to achieve the above object, one aspect of the wood-covered RC member according to the present invention is as follows:
This method is characterized in that a wooden surface material is attached to the surface of a reinforced concrete member that has been constructed or manufactured in advance, covering the RC member.

In this manner, wooden surface materials are attached to the surface of reinforced concrete members that have been constructed or fabricated in advance, eliminating the need for stain prevention measures, making effective use of wooden materials, and providing building components with the strength and rigidity of reinforced concrete members.

Here, the wooden paneling that makes up the wood-covered RC members also has a certain degree of rigidity, so the wooden paneling functions as a structural material and also as a design material that imparts the aesthetic appeal of wood.

In addition, "pre-constructed reinforced concrete members" includes RC members that have already been constructed on-site, such as RC columns, RC beams, RC walls, and RC slabs, and includes both newly constructed RC members and existing RC members that have been in place for several years or even several decades. On the other hand, "pre-fabricated reinforced concrete members" includes precast concrete members (precast RC members) that are manufactured in factories, etc. Furthermore, in this specification, "RC members" includes not only literal RC members, but also SRC members.

In another aspect of the wood-covered RC member according to the present invention,
The wooden surface material is fixed to the surface of the RC member with an adhesive.

In this aspect, the wood surface material is fixed to the surface of the RC member via adhesive, resulting in a wood-covered RC member with excellent manufacturability and workability.

In another aspect of the wood-covered RC member according to the present invention,
The wood surface material is further fixed to the RC member by an anchor,
The anchors are embedded in positions that do not interfere with the main reinforcement and shear reinforcement embedded in the RC member.

In this embodiment, the wood surface material is fixed to the RC member with anchors in addition to adhesive, resulting in a wood-coated RC member with high fixing strength between the RC member and the wood surface material.

In another aspect of the wood-covered RC member according to the present invention,
The wooden surface material includes an inner wooden surface material on the RC member side and an outer wooden surface material laminated on the inner wooden surface material,
The inner wooden surface material is fixed to the RC member with adhesive and anchors, and the anchors are embedded in positions that do not interfere with the main reinforcement and shear reinforcement embedded in the RC member,
The outer wooden panel is fixed to the inner wooden panel with an adhesive.

In this embodiment, the outer wood panel is fixed to the RC member via adhesive while the inner wood panel is fixed to the RC member with adhesive and anchors. This prevents the anchor heads from being exposed by the outer wood panel, thereby minimizing any deterioration in the appearance and design of the wood-coated RC member.

In another aspect of the wood-covered RC member according to the present invention,
The RC member that has been constructed in advance is a RC column or a RC beam that has been constructed on site.

According to this aspect, since the wood-clad RC member is an RC column or RC beam installed on-site, for example, an existing RC column or RC beam can be renovated into a column or beam member with a wood-like exterior design. Old RC columns and the like often have cracks on their surfaces, but retrofitting a wood surface material to the surface can also help hide cracks on the surface of the RC column, etc.

In another aspect of the wood-covered RC member according to the present invention,
The prefabricated RC member is characterized in that it is one of PCa columns, PCa joints, and PCa beams, which are PCa members made of precast concrete.

In this manner, wood surface materials are retrofitted to the surfaces of prefabricated PCa members, such as PCa columns, PCa joints, and PCa beams, eliminating the need for stain prevention measures and allowing for the efficient production of wood-clad RC members that comprise PCa members and wood surface materials.

Furthermore, one aspect of the method for forming a wood-covered RC member according to the present invention is to
This method is characterized in that a wooden surface material is attached to the surface of a reinforced concrete member that has been constructed or manufactured in advance, thereby covering the RC member.

According to this method, by retrofitting a wooden surface material onto the surface of a reinforced concrete member that has already been constructed or fabricated, it is possible to efficiently construct or fabricate a wood-covered RC member, eliminating the need for stain prevention measures.

Another aspect of the method for forming a wood-covered RC member according to the present invention is to
The wooden surface material is fixed to the surface of the RC member with an adhesive.

According to this aspect, by fixing a wooden surface material to the surface of the RC member using adhesive, wood-covered RC members can be constructed or manufactured more efficiently.

Another aspect of the method for forming a wood-covered RC member according to the present invention is to
The wooden panel is further fixed to the RC member with anchors, and the anchors are embedded in positions that do not interfere with the main reinforcement and shear reinforcement embedded in the RC member.

According to this aspect, by adding a wooden surface material to an RC member with adhesive and then fixing it with anchors, it is possible to construct or manufacture a wood-covered RC member with high fixing strength between the RC member and the wooden surface material.

In another aspect of the method for forming a wood-covered RC member according to the present invention,
The wooden surface material includes an inner wooden surface material on the RC member side and an outer wooden surface material laminated on the inner wooden surface material,
The inner wooden surface material is fixed to the RC member with adhesive and anchors, and the anchors are buried in advance in a position that does not interfere with the main reinforcement and shear reinforcement embedded in the RC member, or are buried by post-construction,
After the inner wooden panel is fixed to the RC member, the outer wooden panel is fixed to the inner wooden panel with an adhesive.

According to this method, by fixing the inner wooden panel to the RC member with adhesive and anchors, and fixing the outer wooden panel to the inner wooden panel with adhesive, the outer wooden panel prevents the anchor heads from being exposed, minimizing any deterioration in the appearance design of the wood-covered RC member.

When anchors are driven into constructed or fabricated RC members, the positions of the main reinforcement and shear reinforcement are identified based on the design cover and reinforcement pitch, and the anchors are driven into positions that do not interfere with these rebars. On the other hand, when RC members are fabricated as PCa members in a factory, the anchors are installed when the main reinforcement and shear reinforcement are arranged, and then concrete is poured, and the RC member is fabricated with the anchors already installed. Therefore, these anchors can be anchors with headed ends that are buried inside the RC member, or anchors that span a pair of opposing side surfaces of the RC member, making it possible to attach wood paneling with highly pull-out-resistant anchors.

As can be understood from the above explanation, the wood-coated RC member and its forming method of the present invention can provide a wood-coated RC member and its forming method that eliminates the need for stain prevention measures.

FIG. 2 is a perspective view of an example of a wood-covered RC member according to the first embodiment. 1 is a perspective view of an example of a wood-covered RC member according to a second embodiment, and is also a process diagram of an example of a method for forming the wood-covered RC member according to the first embodiment. FIG. FIG. 10 is a longitudinal cross-sectional view of an example of a wood-covered RC member according to the second embodiment. FIG. 10 is a longitudinal cross-sectional view of an example of a wood-covered RC member according to the third embodiment. FIG. 10 is a longitudinal cross-sectional view of an example of a wood-covered RC member according to the fourth embodiment. FIG. 10 is an oblique view of an example of a wood-covered RC member according to the fifth embodiment, and is also a process diagram of an example of a method for forming a wood-covered RC member according to the second embodiment. 1 is a process diagram of an example of a method for forming a wood-covered RC member according to the first embodiment. FIG. 6A , which is a process diagram of an example of a method for forming a wood-covered RC member according to the first embodiment. FIG. 10 is a process diagram of an example of a method for forming a wood-covered RC member according to the second embodiment. 7A and 7B are process diagrams illustrating an example of a method for forming a wood-covered RC member according to the second embodiment.

An example of a wood-covered RC member according to an embodiment and a method for forming the same will be described below with reference to the accompanying drawings. Note that in this specification and drawings, substantially identical components will be designated by the same reference numerals, and redundant explanations may be omitted.

[Wood-covered RC member according to the first embodiment]
First, an example of a wood-covered RC member according to the first embodiment will be described with reference to Fig. 1. Fig. 1 is a perspective view of an example of a wood-covered RC member according to the first embodiment.

The wood-clad RC member 50 is constructed by attaching a wood panel 20 to each of the four sides of a previously constructed or prefabricated reinforced concrete RC member 10, a long, slender rectangular parallelepiped. This covers all four sides of the RC member 10. The RC member 10 is an existing RC column or beam, or a precast concrete column, beam, or joint (PCa column, beam, or joint) manufactured in a factory. An existing RC column, for example, is an RC column that constitutes an old RC building. In the case of a PCa member, it is a PCa column that has been prefabricated in a factory. Here, the PCa member may be a wide RC wall or RC slab (floor), and in this case, a wide timber panel is fixed to a pair of wide surfaces of the RC wall, etc.

The RC column 10 has multiple main reinforcements 15 and multiple shear reinforcement bars 16 surrounding each main reinforcement bar 15. Here, the shear reinforcement bars 16 in the RC column 10 are tie bars, and when the RC member 10 is an RC beam, the shear reinforcement bars are stirrups or stirrups.

Various types of surface materials can be used for the wooden surface material 20, including solid wood, laminated wood, laminated veneer lumber (LVL), and plywood.

A wood-covered RC member 50 is formed by fixing a wooden panel 20 to each of the four sides of the RC column 10 using adhesive 30. If the RC member 10 is cylindrical, for example, a single thin wooden panel is wrapped around the side of the RC member 10 to give it a cylindrical shape, thereby covering the periphery of the RC member 10.

Adhesives that can be used include epoxy adhesives, which have excellent water resistance, moisture resistance, alkali resistance, heat resistance, and abrasion resistance; acrylic adhesives, which have a fast curing rate; silicone adhesives, which are flexible and impact resistant; and inexpensive vinyl acetate adhesives.

With the wood-covered RC member 50, a wood surface material 20 is attached via adhesive 30 to the surface of a reinforced concrete RC member 10 that has been constructed or fabricated in advance. This makes effective use of the wood material while eliminating the need for stain prevention measures, and allows the member to become a column or beam member for a building that has the strength and rigidity of the RC member 10.

Furthermore, if the RC member 10 is an RC column that constitutes an old RC building, cracks on the surface can be hidden with the wooden surface material 20, and the column can be renewed to have the exterior design characteristics of wood.

Furthermore, because there is an RC member 10 on the inside, in the event of a fire, the outer wooden surface material will burn and char, but the inner RC member will stop burning, preventing the collapse of the building.In addition, if wood is cut down to use as the wooden surface material in the formation of the wood-covered RC member 50, by planting an amount of wood equivalent to the amount cut down, it is possible to reduce _CO2 emissions equivalent to the carbon content of the wood used, which leads to a reduction in environmental impact.

[Wood-covered RC member according to the second embodiment]
Next, an example of a wood-covered RC member according to the second embodiment will be described with reference to Figures 2A and 2B. Figure 2A is a perspective view of the example of the wood-covered RC member according to the second embodiment, and Figure 2B is a longitudinal cross-sectional view of the example of the wood-covered RC member according to the second embodiment. Figure 2A also shows a process diagram of an example of a method for forming the wood-covered RC member according to the first embodiment, which will be described below.

Wood-coated RC member 50A differs from wood-coated RC member 50 in that four wood panelings 20A are adhered to each of the four sides of rectangular RC member 10 using adhesive 30, and the wood panelings 20A are further fixed in place with anchors 40 embedded in RC member 10.

The wooden panel 20A has multiple countersunk grooves 25 on its outer surface, and anchors 40 are installed later and screwed or driven into the RC member 10 through the countersunk grooves 25.

The anchor 40 has a shaft 41 with a sharp tip and a head 42 at the end of the shaft 41. The shaft 41 is embedded in a position that does not interfere with the main reinforcement 15 or shear reinforcement 16 of the RC member 10, and the head 42 is fixed to the bottom of the countersunk groove 25.

Furthermore, by filling the seat groove 25 with filler material 26 that conceals the head 42 of the anchor 40, exposure of the head 42 is prevented, minimizing deterioration of the external design.

The wood-coated RC member 50A not only achieves the same effects as the wood-coated RC member 50 described above, but also forms a wood-coated RC member with high fixing strength between the RC member 10 and the wood panel 20, as the wood panel 20A is fixed to the RC member 10 with adhesive 30 and anchors 40.

[Wood-covered RC member according to the third embodiment]
Next, an example of a wood-covered RC member according to a third embodiment will be described with reference to Fig. 3. Fig. 3 is a vertical cross-sectional view of an example of a wood-covered RC member according to the third embodiment.

Wood-coated RC member 50B differs from wood-coated RC member 50A in that it is equipped with an anchor 40A having heads 42 and 43 at both ends of a shaft 41.

For example, the inner head 43 embedded in the RC member 10 is manufactured integrally with the shaft 41, and the outer head that secures the wooden panel 20A is an add-on head 42 that can be attached and detached to the shaft 41.

The RC member 10 in the illustrated example is, for example, a precast concrete column, and during production in a factory, the RC member 10 is first produced with the head 43 and shaft 41 already embedded. Furthermore, the wooden surface material 20A is not used as a formwork when producing the RC member 10. Instead, a formwork for pouring concrete is used to produce the RC member 10, and then the formwork is removed and the wooden surface material 20A is attached to produce the wood-coated RC member 50B. This production method eliminates the need for stain prevention measures when producing the wooden surface material 20A, and the wooden surface material 20A can be retrofitted to the "previously produced RC member 10."

When the formwork used for pouring concrete is removed, the ends of the shanks 41 of multiple anchors 40A are exposed from the side of the resulting RC member 10. Wooden paneling 20A, each equipped with a counterbore groove 25 at a position corresponding to each shank 41, is attached to the side of the RC member 10 via adhesive 30. The screw holes in the attached heads 42 are then threaded into the threaded grooves at the ends of the shanks 41 that protrude into the counterbore grooves 25, thereby securing the wooden paneling 20A to the RC member 10 with the adhesive 30 and the anchors 40A. As with the wood-covered RC member 50A, filler material 26 is then packed into the counterbore grooves 25 to prevent the attached heads 42 from being exposed, minimizing degradation of the exterior design.

The wood-coated RC member 50B achieves the same effects as the wood-coated RC member 50A described above. In addition, the anchors 40A embedded in the RC member 10 also have heads 43 on the inner ends, resulting in a wood-coated RC member with even stronger fastening strength between the RC member 10 and the wooden surface material 20A, thanks to the anchors 40A having higher pull-out resistance.

[Wood-covered RC member according to the fourth embodiment]
Next, an example of a wood-covered RC member according to the fourth embodiment will be described with reference to Fig. 4. Here, Fig. 4 is a vertical cross-sectional view of an example of a wood-covered RC member according to the fourth embodiment.

Wood-coated RC member 50C differs from wood-coated RC members 50A and 50B in that the shank 41A of the anchor 40B extends across the opposing side surfaces of the RC member 10, with both ends of the anchor 40B protruding into the counterbore grooves 25 in the wood panel 20A on both sides, and retrofit heads 44 attached to both ends.

The RC member 10 shown in the figure is produced by installing a rectangular formwork (not shown) to surround the main reinforcement bars 15 and shear reinforcement bars 16, penetrating the shaft 41A of the anchor 40B into the opposing formwork, using the end of the shaft 41A protruding outside the formwork to secure the back of the formwork with a separator (not shown), and filling the formwork with concrete to produce the RC member 10.

When the formwork used for pouring concrete is removed, the end of a common shaft 41A protrudes from the opposing side of the resulting RC member 10. Multiple such shafts 41A protrude from each side of the RC member 10. Then, a wooden panel 20A, equipped with a counterbore groove 25 at a position corresponding to the shaft 41A, is attached to the side of the RC member 10 via adhesive 30. After that, the screw hole in the attached head 44 is threaded into the screw groove at the end of the shaft 41A protruding into the counterbore groove 25, thereby securing the wooden panel 20A to the RC member 10 with the adhesive 30 and anchor 40B. Then, as with the wood-covered RC member 50A, filling material 26 is packed into the counterbore groove 25 to prevent the attached head 44 from being exposed, minimizing degradation of the exterior design.

The wood-coated RC member 50C achieves the same effects as the wood-coated RC member 50A described above. In addition, the wood panel 20A is fixed to both sides of the RC member 10 with anchors 40B that straddle the opposing sides of the RC member 10. This results in a wood-coated RC member with even stronger fixing strength between the RC member 10 and the wood panel 20A, thanks to the anchors 40B having even higher pull-out resistance.

[Wood-covered RC member according to the fifth embodiment]
Next, an example of a wood-covered RC member according to the fifth embodiment will be described with reference to Fig. 5. Here, Fig. 5 is a perspective view of an example of a wood-covered RC member according to the fifth embodiment. Here, Fig. 5 is also a process diagram of an example of a method for forming a wood-covered RC member according to the second embodiment described below.

Wood-coated RC member 50D differs from wood-coated RC members 50A, 50B, and 50C in that it has an inner wood panel 20B on the RC member 10 side and an outer wood panel 20C laminated to the inner wood panel 20B.

The inner wood panel 20B is fixed to the RC member 10 with adhesive 30 and anchors 40A, similar to the wood panel 20A shown in Figure 3. Here, the inner wood panel 20B may be fixed to the RC member 10 with adhesive 30 alone, similar to the wood panel 20 shown in Figure 1, or with adhesive 30 and post-installed anchors 40, similar to the wood panel 20A shown in Figures 2A and 2B, or with adhesive 30 and anchors 40B that straddle the opposing wood panel 20A, similar to the wood panel 20A shown in Figure 4.

The outer wooden panel 20C is fixed to the inner wooden panel 20B, which is fixed to the RC member 10, using a separate adhesive 30 to form a wood-coated RC member 50D.

In addition to achieving the same effects as the wood-coated RC member 50A described above, the wood-coated RC member 50D has the advantage that the inner wooden panel 20B is covered by the outer wooden panel 20C, which not only prevents the post-installation head 42 of the anchor 40A from being exposed by the outer wooden panel 20C, but also prevents the filler material from being exposed to the outside, further minimizing deterioration of the appearance and design of the wood-coated RC member.

[Method for forming wood-covered RC member according to the first embodiment]
Next, an example of a method for forming a wood-covered RC member according to the first embodiment will be described with reference to Figures 6A, 6B, and 2A. Figures 6A, 6B, and 2A are process diagrams of an example of a method for forming a wood-covered RC member according to the first embodiment, respectively. Here, the methods for forming the wood-covered RC members 50A and 50D shown in Figures 2A and 5 will be described in detail below.

The reinforced concrete member 10 shown in Figure 6A is an reinforced concrete column of an existing rectangular building, and contains numerous cracks C on its surface. In other words, it is a "pre-constructed reinforced concrete member."

As shown in Figure 6B, adhesive 30 is applied to the four sides of the RC member 10, and four wooden paneling pieces 20A are adhered to them.

Next, post-installed anchors 40 are screwed or driven into the RC member 10 through each counterbore groove 25 provided in the wood panel 20A, thereby fixing the four wood panel 20A to the RC member 10 and covering the periphery of the RC member 10. Finally, filler material 26 is filled into each counterbore groove 25 to form the wood-covered RC member 50A shown in Figure 2A.

The forming method shown in the figure makes effective use of the wood surface material 20A, concealing cracks C in the existing RC member 10 while constructing a wood-covered RC member 50A with excellent exterior design.

[Method for forming wood-covered RC member according to the second embodiment]
Next, an example of a method for forming a wood-covered RC member according to the second embodiment will be described with reference to Figures 7A, 7B, and 5. Figures 7A, 7B, and 5 are process diagrams of an example of a method for forming a wood-covered RC member according to the second embodiment, respectively.

As shown in Figure 7A, multiple main reinforcements 15 and multiple shear reinforcement bars 16 for PCa columns are assembled in a factory or other facility. Furthermore, multiple anchors 40A are placed in positions that do not interfere with the main reinforcements 15 and shear reinforcement bars 16, and a rectangular formwork K is then installed. The formwork K has through-holes K1 at positions corresponding to each anchor 40A. After the shank 41 of the corresponding anchor 40A is inserted through the through-hole K1, the post-installation head 42 is screwed onto the shank 41, thereby securing the formwork K to the multiple anchors 40A. The other end of the shank 41 is provided with a head 43 that is manufactured integrally with the shank 41.

Next, concrete is poured into the rectangular formwork K, and after the concrete has hardened, the post-installed heads 42 are removed from the shafts 41, and the formwork K is demolded. Once the formwork K has been demolded, the shafts 41 of multiple anchors 40A are left protruding from each of the four sides of the RC member 10.

An inner wood panel 20B is prepared with countersunk grooves 25 at positions corresponding to the protruding shanks 41. After applying adhesive 30 to the side of the RC member 10, the ends of the shanks 41 of the anchors 40A are inserted into the corresponding countersunk grooves 25, thereby adhering the inner wood panel 20B to the side of the RC member 10. Next, as shown in Figure 7B, an attached head 42 is screwed onto the end of the shank 41 protruding into the countersunk groove 25, thereby fixing the inner wood panel 20B to the RC member 10 with the adhesive 30 and the anchors 40A.

Finally, a separate adhesive 30 is applied to the surface of the inner wooden panel 20B and the outer wooden panel 20C is adhered to it, thereby forming a wood-coated RC member 50D, as shown in Figure 5, in which the inner wooden panel 20B surrounding the four sides of the RC member 10 is further surrounded by the outer wooden panel 20C.

According to the illustrated forming method, the inner wooden panel 20B and outer wooden panel 20C are sequentially attached to the pre-fabricated RC member 10, making it possible to produce the wood-clad RC member 50D using an efficient forming method that makes effective use of the wooden panel while eliminating the need to take measures to prevent the wooden panel from becoming dirty during production.

Other embodiments may be possible in which other components are combined with the configurations described in the above embodiments, and the present invention is in no way limited to the configurations shown here. In this regard, changes can be made without departing from the spirit of the present invention, and can be determined appropriately depending on the application form.

10: RC member (RC column)
15: Main reinforcement 16: Shear reinforcement 20, 20A: Wood surface material 20B: Inner wood surface material 20C: Outer wood surface material 25: Seat groove 26: Filler material 30: Adhesive 40, 40A, 40B: Anchor 41, 41A: Shank 42: Post-attached head (head)
43: Head 44: Post-attached head (head)
50, 50A, 50B, 50C, 50D: Wood-covered RC member K: Formwork C: Crack

Claims (4)

A wooden surface material is attached with an adhesive to the surface of a reinforced concrete member that has been constructed or fabricated in advance, covering the RC member .
Both of the wood panels on the opposing sides of the RC member are further fixed to the RC member by anchors extending across the opposing sides ,
A wood-covered RC member characterized in that the anchors are embedded in positions that do not interfere with the main reinforcement and shear reinforcement embedded in the RC member. 2. The wood-covered RC member according to claim 1 , wherein the pre-constructed RC member is an RC column or RC beam constructed on-site. The wood-covered RC member according to claim 1 , characterized in that the pre-fabricated RC member is a PCa member made of precast concrete, which is one of PCa columns, PCa joints, and PCa beams. A method for forming a wood-covered RC member, characterized in that a wood surface material is attached with an adhesive to the surface of a reinforced concrete RC member that has been previously constructed or fabricated , thereby covering the RC member, and both of the wood surface materials on opposite sides of the RC member are fixed to the RC member with anchors that extend across the opposite sides , and in this process, the anchors are embedded in positions that do not interfere with the main reinforcement and shear reinforcement embedded in the RC member.