JP2025113719A - Column-beam joint structure and its construction method - Google Patents

Abstract

To provide a column-beam joint structure with a high joint strength, and its construction method, for a column-beam joint structure consisting of a concrete column and a wooden beam that are joined with a bracket.SOLUTION: A column-beam joint structure 100 comprises a concrete column 10 joined with a wooden bound beam 30 composed of a pair of wooden beams 40 parallelly aligned with a spacing 45. Fastener pins 51 protrude in from the side surfaces 43 of both the pair of wooden beams 40. A bracket 20 jutting out on the side of the column 10 is sandwiched between the pair of wooden beams 40. The bracket 20 is a cast-in-place concrete body burying the fastener pins 51 in it.SELECTED DRAWING: Figure 4

Description

The present invention relates to a column-beam joint structure and its construction method.

In some building structures, reinforced concrete (RC), steel (S), steel-reinforced concrete (SRC), or even wooden columns are fitted with RC or S brackets extending from their sides. Wooden beams are then bolted to the brackets, and a RC, wooden, or steel deck is then placed on top of the wooden beams. For example, in addition to RC columns constructed on-site, there are also precast concrete (PCa) columns, which are factory-fabricated, transported to the site, and assembled on-site. The use of PCa columns significantly shortens construction time and creates high-quality beam-to-column joints. There are also various types of column and bracket configurations, including RC structures in which the columns and brackets are integrated, and structures with bracket-equipped joints between the upper and lower columns. Furthermore, there are various types of decks supported by wooden beams, including reinforced concrete decks constructed on-site, precast concrete decks, and wooden decks.

In this way, using wooden beams for the beams reduces the burden on the environment, and their light weight makes them easier to handle and install on site, while also providing the excellent exterior design that wood offers.

Patent Document 1 proposes a joining structure for structural members. This joining structure comprises a first structural member having a metal column as a first load-bearing portion and a first fire-resistant coating covering the surface of the first load-bearing portion; a second structural member having a wooden beam as a second load-bearing portion and a second fire-resistant coating covering the surface of the second load-bearing portion; and joining means for joining the first structural member and the second structural member. One end of the joining means is joined to the metal column without the first fire-resistant coating, and the other end is joined to the wooden beam via the second fire-resistant coating. One end of the joining plate forming the joining means is welded to the metal column, and the metal column and wooden beam are joined via the joining means by a bolt and nut serving as fastening means inserted through bolt insertion through-holes in both the joining plate and the wooden beam.

Japanese Patent Application Laid-Open No. 2022-165195

In the wooden beam joint structure described in Patent Document 1, the pillar (joint) and wooden beam are connected by bolts inserted into bolt insertion through-holes in both the joint plate and the wooden beam, and then tightened with nuts. This raises concerns that the joint structure may become loose and that the joint strength of the joint structure may be reduced.

The present invention was made in consideration of the above-mentioned problems, and aims to provide a column-beam joint structure in which a concrete column and a wooden beam are joined via a bracket, which is less likely to rattle and has high joint strength, and a construction method for the same.

In order to achieve the above object, one aspect of the column-beam joint structure according to the present invention is as follows:
A column-beam joint structure in which a concrete column and a pair of wooden beams are joined together with a gap between them,
Fasteners extend from both sides of the pair of wooden beams,
A bracket extending laterally from the pillar is sandwiched between the pair of wooden beams,
The bracket is a cast-in-place concrete body in which the fastener is embedded.

In this configuration, the fasteners that protrude from the sides of the pair of wooden beams that form the laminated wooden beam are embedded in brackets made of cast-in-place concrete that protrude laterally from the column, resulting in a column-beam joint structure with less rattle and higher joint strength. Here, the reinforcing bars for the bracket are fixed in the panel zone (or joint) of the column, and cast-in-place concrete is placed with the reinforcing bars for the bracket and the fasteners that protrude from the sides of the wooden beam intersecting. Then, the bracket made of cast-in-place concrete is placed, firmly joining the column and laminated wooden beam via the bracket.

Another aspect of the column-beam joint structure according to the present invention is as follows:
A column-beam joint structure in which concrete columns and wooden beams are joined,
A fastener protrudes from the side of the wooden beam,
The wooden beam is disposed on the side of the bracket that projects outward from the side of the pillar,
The bracket is a cast-in-place concrete body in which the fastener is embedded.

In this configuration, the fasteners projecting from the side of one wooden beam are embedded in brackets made of cast-in-place concrete projecting laterally from the column, resulting in a column-beam joint structure with high joint strength and less rattle. For example, this type of column-beam joint structure is ideal when, for various reasons, it is desired to install a single wooden beam only on the exterior side of a column located on the perimeter of a building.

Another aspect of the column-beam joint structure according to the present invention is as follows:
The panel zone of the column to which the bracket is joined is a cast-in-place concrete body.

In this embodiment, because the column panel zone and bracket are made of cast-in-place concrete, for example, when both are constructed by continuous concrete pouring, there is no need to roughen the side of the panel zone, which has already hardened, prior to pouring the concrete for the bracket, making it possible to construct a column-beam joint structure with excellent workability.

Here, while it is preferable that the concrete pouring for the panel zone and bracket be carried out continuously as described above, discontinuous concrete pouring is also possible, for example, where the concrete pouring for the panel zone is carried out first, and the concrete pouring for the bracket is carried out after the concrete in the panel zone has hardened.

Another aspect of the column-beam joint structure according to the present invention is as follows:
The panel zone of the column to which the bracket is joined and at least one of the general portions of the column above and below it are made of cast-in-place concrete.

In this embodiment, the panel zone of the column and the general section and bracket of at least one of the columns above and below it are made of cast-in-place concrete. For example, when the general section of the column, panel zone, and bracket are constructed by continuous concrete pouring, there is no need to roughen the pouring joint surface of the general section of the column, which has already hardened prior to pouring the concrete in the panel zone. Furthermore, there is no need to roughen the side surface of the panel zone, which has already hardened prior to pouring the concrete in the bracket, making it possible to construct a column-beam joint structure with excellent workability.

Here, "the general part of at least one of the columns above and below the panel zone of the column" includes the general parts of the columns both above and below the panel zone, and the general part of the column on either side of the panel zone.

Here, while it is preferable that the concrete pouring for the panel zone and the general sections and brackets of the columns above and below the panel zone be carried out continuously as described above, discontinuous concrete pouring is also possible, for example, where the concrete for the general sections of the columns is poured first, the concrete for the panel zone is poured after the concrete for the general sections has hardened, and the concrete for the brackets is poured after the concrete for the panel zone has hardened.

Another aspect of the column-beam joint structure according to the present invention is as follows:
The fastener is one of a drift pin, a lag screw bolt, a wood screw, a nail, a bolt, and a glue-in rod.

In this embodiment, various fasteners, such as lag screw bolts and drift pins, can be used to join wooden beams and brackets with high strength. Here, glue-in rods (GIRs) can also be called glued-in rods (GIRs), and are a construction method (method) for joining wooden components by drilling holes in them, inserting steel rods into the holes, and filling them with resin adhesive. Fasteners include a combination of resin adhesive and steel rods.

In addition, one aspect of the construction method for a column-beam joint structure according to the present invention is as follows:
A construction method for a column-beam joint structure in which a concrete column and a pair of wooden beams are joined together with a gap between them to construct a column-beam joint structure,
A reinforcing bar for a bracket is protruded from the side of the pillar,
Fasteners are protruded from both side surfaces of the pair of wooden beams, and the fasteners are intersected with the reinforcing bars, and the pair of wooden beams are arranged so as to sandwich the reinforcing bars;
The pair of wooden beams function as formwork, and separate formwork is assembled in necessary locations including below the reinforcing bars, and concrete is poured into the formwork to construct a bracket, which is a cast-in-place concrete body, and the formwork is then removed to construct the column-beam joint structure.

In this embodiment, fasteners projecting from the sides of a pair of wooden beams forming a laminated wooden beam intersect with reinforcing bars for brackets projecting from the side of a column, and the pair of wooden beams are arranged so that the reinforcing bars are sandwiched between them. While the pair of wooden beams function as formwork, separate formwork is assembled in necessary locations, including below the reinforcing bars. Concrete is poured inside the formwork and the brackets are installed. This eliminates the need to remove the pair of wooden beams, improving the work efficiency of both assembling and removing the formwork, and enabling the construction of a column-beam joint structure with high joint strength and excellent workability. Here, "assembling separate formwork in necessary locations, including below the reinforcing bars" means, for example, assembling formwork below the reinforcing bars and on the sides of the reinforcing bars where there are no columns (or panel zones) or pair of wooden beams.

Another aspect of the construction method for a column-beam joint structure according to the present invention is as follows:
A construction method for a column-beam joint structure in which a concrete column and a wooden beam are joined to construct a column-beam joint structure,
A reinforcing bar for a bracket is protruded from the side of the pillar,
A fastener is protruded from a side surface of the wooden beam, and the fastener intersects with the reinforcing bar, and the wooden beam is disposed next to the reinforcing bar;
While the wooden beams function as formwork, separate formwork is assembled in necessary locations including below the reinforcing bars, and concrete is poured into the formwork to construct a bracket, which is a cast-in-place concrete body, and the formwork is then removed to construct the beam-column joint structure.

In this configuration, a fastener projecting from one side of a wooden beam intersects with a racket reinforcing bar projecting from the side of a column, and the wooden beam is positioned to the side of the reinforcing bar. While the wooden beam functions as a formwork, separate formwork is assembled in necessary locations, including below the reinforcing bar. Concrete is poured inside the formwork, and brackets are installed. This eliminates the need to remove the wooden beam, improving the work efficiency of both assembling and removing the formwork, and enabling the construction of a column-beam joint structure with high joint strength and excellent workability.

Another aspect of the construction method for a column-beam joint structure according to the present invention is as follows:
A formwork is also installed around the panel zone of the column to which the bracket is joined, and concrete is poured inside the formwork to construct the panel zone and bracket, which are cast-in-place concrete bodies, and the formwork is then removed to construct the column-beam joint structure.

In this embodiment, the column panel zone and bracket are cast-in-place concrete bodies. For example, by constructing both by continuous concrete pouring, there is no need to roughen the side of the panel zone, which has already hardened prior to pouring the concrete for the bracket, allowing for the construction of a column-beam joint structure with excellent workability.

Another aspect of the construction method for a column-beam joint structure according to the present invention is as follows:
Formwork is installed around the panel zone of the column to which the bracket is joined, and also around the general part of at least one of the columns above and below it, and concrete is poured inside the formwork to construct the panel zone, bracket, and general part of the column, which are cast-in-place concrete bodies, and the formwork is then removed to construct the column-beam joint structure.

In this embodiment, the panel zone of the column, the general section of at least one of the columns above and below it, and the bracket are made of cast-in-place concrete. For example, by constructing these by continuous concrete pouring, there is no need to roughen the joint surface of the general section of the column, which has already hardened prior to pouring the concrete in the panel zone. Furthermore, there is no need to roughen the side surface of the panel zone, which has already hardened prior to pouring the concrete in the bracket, making it possible to construct a column-beam joint structure with excellent workability.

As can be understood from the above explanation, the column-beam joint structure and construction method of the present invention can provide a column-beam joint structure in which a concrete column and a wooden beam are joined via brackets, which is less likely to rattle and has high joint strength, and a construction method for the same.

FIG. 1 is a process diagram illustrating an example of a construction method for a beam-column joint structure according to an embodiment. FIG. 2 is a view corresponding to FIG. 1 and showing another example of a fastener that protrudes from the side surface of a wooden beam. 1 , and is a process diagram illustrating an example of a construction method for a beam-column joint structure according to an embodiment. 2 , and is a process diagram illustrating an example of a construction method for a column-beam joint structure according to an embodiment, and is a perspective view showing an example of a column-beam joint structure according to an embodiment.

An example of a beam-column joint structure according to an embodiment 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.

[Column-beam joint structure according to the embodiment and its construction method]
An example of a column-beam joint structure and its construction method according to an embodiment will be described with reference to Figures 1 to 4. Figures 1, 3, and 4 are process diagrams illustrating an example of a construction method for a column-beam joint structure according to an embodiment, respectively. Figure 4 is a perspective view showing an example of a column-beam joint structure according to an embodiment. Figure 2 corresponds to Figure 1 and shows another example of a fastener protruding from the side of a wooden beam. In the following figures, illustrations of main reinforcement bars, ties, etc. of the column 10 are omitted.

The following explanation describes a method of joining the column 10 and the wooden beam 30 via a bracket 20 by installing the bracket 20 on-site on one side 11 of the column 10, but this installation method may also be applied to configurations other than those shown in the illustrations.

For example, in addition to the bracket 20, the panel zone to which the bracket 20 is joined may also be constructed continuously on-site, or in addition to the bracket 20, the panel zone to which the bracket 20 is joined and the general parts of the columns 10 above and below it to which the panel zone is joined may also be constructed continuously on-site.

In addition, instead of a laminated wooden beam 30, a single wooden beam 40 may be joined to the bracket 20 on-site.

Furthermore, the illustrated construction method describes a method in which a bracket 20 is installed on-site to one side 11 of a pillar 10, but a similar method may also be used in which brackets 20 are installed on the other side 11 of the pillar 10, and a laminated wooden beam 30 is joined via the bracket 20.

As shown in Figure 1, rebar 25 for a bracket 20, shown by dotted lines and to be installed on site, protrudes from the side surface 11 of a reinforced concrete column 10. This column 10 is, for example, a precast concrete (PCa) column manufactured in a factory. During the manufacture of the PCa column 10, a portion (anchoring portion) of the rebar 25 is placed inside the column (panel zone) rebar (main reinforcement and tie bars), and concrete for the column is poured, thereby producing a PCa column 10 with rebar 25 protruding laterally from the side surface 11 as shown in Figure 1. As mentioned above, when the panel zone is installed on site along with the bracket, formwork for the bracket and formwork for the panel zone are assembled on site, and concrete is poured continuously into both formworks, for example, to install both the panel zone and bracket simultaneously.

Pin holes 46 are provided at corresponding positions on both ends 44 of a pair of wooden beams 40, penetrating the thickness of the wooden beams 40 across the left and right side surfaces 43. By driving the ends of drift pins 51 (an example of fasteners) into each pin hole 46 of one wooden beam 40, multiple drift pins 51 protrude from the side surfaces 43.

One wooden beam 40 is then placed to the side of the bracket reinforcing bars 25 so that each drift pin 51 crosses the reinforcing bars 25, and the ends of the corresponding drift pins 51 are driven into each pin hole 46 of the other wooden beam 40. This results in a pair of wooden beams 40 being placed on the left and right sides of the bracket reinforcing bars 25, with multiple drift pins 51 connecting the two (in other words, extending from both sides) crossing the reinforcing bars 25.

The wooden beams 40 that make up the laminated wooden beam 30 are formed by stacking a large number of sawn boards with their fiber directions alternately perpendicular to one another and then gluing them together. In addition to being a laminate of sawn boards, the wooden beams 40 may also be made of materials such as cross-laminated timber (CLT) or laminated veneer lumber (LVL).

In the building frame, both ends of a laminated wooden beam 30 suspended by, for example, a crane are positioned relative to the reinforcing bars 25 for the brackets of a pair of columns 10 erected with a predetermined span between them, and the pair of wooden beams 40 are supported from below by shoring as necessary.

Instead of the drift pin 51 shown in Figure 1, as shown in Figure 2, the tips of multiple lag screw bolts 53 (another example of fasteners) can be screwed into tip holes provided in the side surface 43 of the wooden beam 40, causing the multiple lag screw bolts 53 to protrude from the side surface 43, and a pair of wooden beams 40 can be arranged so that the multiple lag screw bolts 53 provided on both wooden beams 40 cross the reinforcing bars 25.

Next, as shown in Figure 3, the ends 44 of a pair of wooden beams 40 arranged on the left and right sides of the reinforcing bar 25 function as formwork, and a separate formwork K is assembled in the gap 45 between the pair of wooden beams 40 to cover the front of the bracket, and a separate formwork (not shown) is also assembled below the reinforcing bar 25.

Next, as shown in Figure 4, concrete is poured into the space surrounded by the end portions 44 of a pair of wooden beams 40, which function as formwork, and another formwork K. After the concrete has hardened, the formwork K is removed, thereby constructing a bracket 20 joined to the column 10 via reinforcing bars 25, and constructing a beam-column joint structure 100 in which the pair of wooden beams 40 are joined to the bracket 20 by multiple drift pins 51 embedded inside the bracket 20.

More specifically, brackets 20 are installed on-site simultaneously or sequentially to a pair of columns 10 that form the building frame, and a column-beam joint structure 100 is constructed in which both ends of a laminated wooden beam 30 are joined to the corresponding column 10 via each bracket 20.

In the example shown in Figure 4, the lower surfaces 41 of each of the pair of wooden beams 40 and the lower surface 21 of the bracket 20 are flush with each other, and similarly, the upper surfaces 42 of each of the pair of wooden beams 40 and the upper surface 22 of the bracket 20 are also flush with each other.

The upper surfaces 42 of the pair of wooden beams 40 and the upper surfaces 22 of the brackets 20 are flush with each other, allowing a floor slab (not shown) to be placed flatly and stably. This floor slab can take a variety of forms, including PCa slabs (PCa reinforced concrete slabs, PCa prestressed concrete slabs (PC slabs)), PC composite slabs made from half PCa slabs and on-site constructed slabs, ALC (Autoclaved Lightweight Aerated Concrete) panels, CLT panels, and on-site constructed slabs (concrete slabs).

In addition, because the underside 41 of each of the pair of wooden beams 40 is flush with the underside 21 of the bracket 20, a ceiling panel (not shown) can be installed flatly and stably against the underside 41 of the end 44 of the laminated wooden beam 30 and the underside 21 of the bracket 20 located between them.

According to the construction method shown in the illustration, a pair of wooden beams 40 can function as formwork when constructing the bracket 20, and since the pair of wooden beams 40 do not need to be demolded, the assembly and demolding of part of the formwork can be omitted, improving the on-site construction of the bracket 20.

Furthermore, with the illustrated column-beam joint structure 100, fasteners 51 protruding from both side surfaces 43 of a pair of wooden beams 40 that form the laminated wooden beam 30 are embedded in brackets 20 made of cast-in-place concrete that protrude laterally from the column 10, resulting in a column-beam joint structure with high joint strength.

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: Pillar (PCa pillar)
11: Side 20: Bracket 21: Bottom 22: Top 25: Reinforcement bar for bracket (reinforcement bar)
30: Laminated wooden beam 40: Wooden beam 41: Underside 42: Upper surface 43: Side 44: End 45: Gap 46: Pin hole 51: Fastener (drift pin)
53: Fastener (lag screw bolt)
100: Column-beam joint structure K: Formwork

Claims (9)

A column-beam joint structure in which a concrete column and a pair of wooden beams are joined together with a gap between them,
Fasteners extend from both sides of the pair of wooden beams,
A bracket extending laterally from the pillar is sandwiched between the pair of wooden beams,
A beam-column joint structure, characterized in that the bracket is a cast-in-place concrete body in which the fastener is embedded. A column-beam joint structure in which concrete columns and wooden beams are joined,
A fastener protrudes from the side of the wooden beam,
The wooden beam is disposed on the side of the bracket that projects outward from the side of the pillar,
A beam-column joint structure, characterized in that the bracket is a cast-in-place concrete body in which the fastener is embedded. The beam-column joint structure described in claim 1 or 2, characterized in that the panel zone of the column to which the bracket is joined is a cast-in-place concrete body. The beam-column joint structure described in claim 1 or 2, characterized in that the panel zone of the column to which the bracket is joined and the general portion of at least one of the columns above and below it are made of cast-in-place concrete. The beam-column joint structure described in claim 1 or 2, characterized in that the fastener is one of the following: a drift pin, a lag screw bolt, a wood screw, a nail, a bolt, or a glue-in rod. A construction method for a column-beam joint structure in which a concrete column and a pair of wooden beams are joined together with a gap between them to construct a column-beam joint structure,
A reinforcing bar for a bracket is protruded from the side of the pillar,
Fasteners are protruded from both side surfaces of the pair of wooden beams, and the fasteners are intersected with the reinforcing bars, and the pair of wooden beams are arranged so as to sandwich the reinforcing bars;
This construction method for a column-beam joint structure is characterized in that, while the pair of wooden beams function as formwork, separate formwork is assembled in necessary locations including below the reinforcing bars, concrete is poured into the formwork to construct a bracket which is a cast-in-place concrete body, and the formwork is removed to construct the column-beam joint structure. A construction method for a column-beam joint structure in which a concrete column and a wooden beam are joined to construct a column-beam joint structure,
A reinforcing bar for a bracket is protruded from the side of the pillar,
A fastener is protruded from a side surface of the wooden beam, and the fastener intersects with the reinforcing bar, and the wooden beam is disposed next to the reinforcing bar;
This construction method for a column-beam joint structure is characterized by the following: while the wooden beam functions as a formwork, separate formwork is assembled in necessary locations including below the reinforcing bars, concrete is poured into the formwork to construct a bracket, which is a cast-in-place concrete body, and the formwork is removed to construct the column-beam joint structure. The construction method for a column-beam joint structure described in claim 6 or 7, characterized in that formwork is also installed around the panel zone of the column to which the bracket is joined, concrete is poured into the formwork to construct the panel zone and bracket, which are cast-in-place concrete bodies, and the formwork is then removed to construct the column-beam joint structure. The construction method for a column-beam joint structure described in claim 6 or 7, characterized in that formwork is installed around the panel zone of the column to which the bracket is joined, and also around the general portion of at least one of the columns above and below it, and concrete is poured inside the formwork to construct the panel zone, bracket, and general portion of the column as a cast-in-place concrete body, and the formwork is then removed to construct the column-beam joint structure.