Joint structure and method of constructing joint structure

Abstract

To provide a joint structure or the like capable of realizing a frame easy to construct and excellent in strength.SOLUTION: A joint structure 1 joins a column 2 and a beam 4 via a joint part 3 having a concrete part, The beam 4 has an end beam 41 provided on a side surface of the joint part 3, and an intermediate beam 42 continuous with the end beam 41. The intermediate beam 42 is a beam-shaped precast member using a woody material and is provided with a horizontal reinforcing bar 43 projecting from an end part in a material axial direction to a joint part 3 side. The end beam 41 has a concrete part by cast-in-place concrete, a horizontal joint reinforcing bar 31 is embedded so as to straddle the joint part 3 and the concrete part of the end beam 41, and the end parts of the horizontal reinforcing bar 43 and the joint reinforcing bar 31 are connected by a joint 44 in the concrete part of the end beam 41.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a column-beam joint structure and a method for constructing the joint structure. [Background technology]

[0002] When joining wooden members in a wooden rigid frame structure with wooden columns and beams, it is common to insert a steel material protruding from one wooden member, such as a glued-in rod (GIR), into a hole in the axial direction of the other wooden member. The wooden members can be joined by filling the hole with a filler such as an adhesive (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-8273 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when this method is used for beam members, it is necessary to move long wooden members in the axial direction at the construction site and insert steel into the holes, which is difficult to implement. In addition, since the grain direction of columns and beams is generally perpendicular, if this method is applied to the joints between columns and beams, steel such as GIR will be inserted perpendicular to the grain of one of the members, which will cause strength problems.

[0005] The present invention has been made in consideration of the above problems, and has an object to provide a joint structure etc. that can realize a frame that is easy to construct and has excellent strength. [Means for solving the problem]

[0006] The first invention for solving the above problem is a joint structure in which a column and a beam are joined via a joint having a concrete portion, the beam having an end beam provided on the side of the joint and an intermediate beam continuing from the end beam, the intermediate beam being a beam-shaped precast member made of wood, having a horizontal reinforcing bar protruding from the end in the material axis direction toward the joint, the end beam having a concrete portion made of cast-in-place concrete, a horizontal joining reinforcing bar buried so as to straddle the joint and the concrete portion of the end beam, and the ends of the horizontal reinforcing bar and the joining reinforcing bar being connected to each other by a joint within the concrete portion of the end beam.

[0007] In the present invention, a beam is divided into end beams and intermediate beams, and environmentally and aesthetically superior wood materials are used for the intermediate beams, while reinforced concrete is used for the joints of the beams and end beams, thereby realizing a frame with excellent strength. As for the intermediate beams, precast members (intermediate beams) manufactured in advance at a factory or the like are dropped in from above, and the joint rebars at the joints and the horizontal rebars of the intermediate beams can be connected with joints, so there is no need to move the intermediate beams in the material axis direction as described above, improving workability. Furthermore, by using reinforced concrete for the joints, it is possible to avoid the problem of rebars being inserted perpendicular to the grain of the wooden members, as described above.

[0008] Furthermore, by locating the joint at the end beam position, it is possible to avoid connections between rebars at joints where the reinforcement is dense, while realizing hinge relocation that shifts the bending yield point of the frame to the center of the beam. This improves the performance of the joint structure and increases the strength of the entire frame.

[0009] The pillars are, for example, reinforced concrete members, or may be composite structures with concrete filled inside the outer timber shell, or may be wooden members. The columns can be made of reinforced concrete, wood, or a composite structure of concrete with a timber exterior, and the type of structure used can be determined taking into consideration strength, fire resistance, environmental aspects, and design aspects.

[0010] It is also preferred that the joint has a composite structure with concrete filled inside the outer timber. It is also preferred that the end beam has a composite structure with concrete filled inside the outer timber. This allows the strength of the components to be maintained by the concrete, while leaving the wood exposed allows the original beauty of wooden construction to be expressed in the joints and end beams. Also, by using reinforced concrete for the interior, fireproofing is no longer necessary for the exterior wood, reducing construction labor and costs.

[0011] The second invention is a method for constructing a joint structure according to the first invention, characterized in that, when constructing the joint structure of the first invention, the intermediate beam is dropped from above into the construction location of the intermediate beam, the ends of the joint reinforcing bars and the horizontal reinforcing bars are connected to each other with the joint, and then concrete is poured into the end beam. A second invention is a method for constructing the joint structure of the first invention. Effect of the Invention

[0012] The present invention can provide a joint structure etc. that can realize a frame that is easy to construct and has excellent strength. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 shows a joint structure 1. [Diagram 2] 1A to 1C are diagrams showing a method of constructing the joint structure 1. [Diagram 3] A diagram showing a joint 3a and an end beam 41a. [Figure 4] An example in which the joint 3 and column 2 are made into a single precast member. [Diagram 5] An example of beam 4 being a double beam. [Figure 6] FIG. 2 is a diagram showing a joint structure 1a. [Figure 7] An example in which joints 3, 3a and column 2a are made into a single precast member. [Figure 8] FIG. [Figure 9] FIG. [Figure 10] FIG. 4 is a diagram showing a method for constructing the joint structure 1b. [Figure 11] An example in which the column 2b and the outer timber 32 of the joint 3a are made into a single precast member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0015] [First embodiment] (1.Joint structure 1) 1(a) and (b) are diagrams showing a joint structure 1 according to a first embodiment of the present invention. Fig. 1(a) is a diagram showing the joint structure 1 as seen from the front, and Fig. 1(b) is a horizontal cross section taken along line AA in Fig. 1(a).

[0016] The joint structure 1 of this embodiment joins a column 2 and a beam 4 at a joint portion (panel zone) 3.

[0017] The columns 2 are reinforced concrete members that are arranged above and below the joints 3, and their cross sections perpendicular to the material axis direction (hereinafter simply referred to as cross sections) are rectangular. However, the cross-sectional shape of the columns 2 is not limited to this, and they may be other polygonal or circular shapes. Vertical reinforcing bars 21 (main reinforcing bars) are embedded inside the columns 2, and the lower end of the reinforcing bars 21 is inserted into the upper part of a sleeve 24 embedded in the lower end of the columns 2.

[0018] The joint 3 is a member made of reinforced concrete. In this embodiment, the horizontal cross section of the joint 3 corresponds to the cross section of the column 2, and the joint 3 is disposed within the range of the cross section of the column 2. In addition, end beams 41 are provided on the left and right side surfaces of the joint 3. The end beams 41 are members made of reinforced concrete.

[0019] The upper part of the reinforcing bar 21 of the column 2 below the joint 3 protrudes upward from the column 2, penetrates the joint 3 from top to bottom, and protrudes further upward from the joint 3. This protruding part is inserted into the lower part of the sleeve 24 of the column 2 above the joint 3. The column 2 above the joint 3 is joined to the joint 3 by filling the sleeve 24 with a filler material (not shown) such as mortar.

[0020] The beams 4 are members provided on the left and right sides of the joint 3, and are composed of the end beams 41 and intermediate beams 42. The intermediate beams 42 are disposed so as to be continuous with the end beams 41. Although not shown in the drawings, in this embodiment, a reinforced concrete slab is provided on the beams 4, and the intermediate beams 42 can also be used as a composite beam structure with the slab.

[0021] The intermediate beam 42 is a wooden member, and is a beam-shaped precast member formed entirely from wooden materials. The wooden material may be, but is not limited to, laminated lumber. Although not shown in the figure, a fire-retardant layer is provided on both sides and the bottom of the intermediate beam 42 to ensure the fire resistance of the intermediate beam 42. The top surface of the intermediate beam 42 is in contact with the above-mentioned concrete slab, so a fire-retardant layer is not necessary, but depending on the structure, a fire-retardant layer may be provided on the top surface of the intermediate beam 42. The fire-retardant layer is made of wood material impregnated with a fire-retardant agent, but is not limited to this, and may be a member having other fire resistance. In some cases, the fire-retardant layer on both sides and the bottom of the intermediate beam 42 may be omitted.

[0022] A portion of the horizontal reinforcing bar 43 is embedded in the end portion of the intermediate beam 42 in the material axis direction. For example, a portion of the horizontal reinforcing bar 43 is inserted into a hole (not shown) in the material axis direction formed in the end portion of the intermediate beam 42, and the hole is filled with a filler material such as mortar. This allows the portion of the horizontal reinforcing bar 43 to be embedded and fixed in the end portion of the intermediate beam 42. The remaining portion of the horizontal reinforcing bar 43 protrudes from the end portion toward the joint 3.

[0023] In this embodiment, a horizontal joint rebar 31 is embedded so as to straddle the joint 3 and the concrete portion of the end beam 41, and the end of the horizontal rebar 43 on the joint 3 side and the end of the joint rebar 31 are connected by a joint 44 within the concrete portion of the end beam 41. As the joint 44, for example, a mechanical joint can be used.

[0024] (2. Construction method of joint structure 1) When constructing the joint structure 1, first, the pillar 2 is provided below the joint 3, as shown in Fig. 2(a). In this embodiment, the pillar 2 is a precast member, and the pillar 2 manufactured in a factory or the like is transported to the site and erected at the construction site. However, the pillar 2 may also be made of cast-in-place concrete, in which case the pillar 2 is formed by arranging reinforcing bars 21 and the like at the construction site, assembling a formwork, and pouring concrete into the formwork.

[0025] Thereafter, as shown in Fig. 2(b), the joint rebars 31 and the like of the joint 3 are arranged, and an intermediate beam 42 manufactured in a factory or the like is transported to the site, dropped into the construction site from above as shown by the arrow, and supported by temporary supports (not shown) or the like and installed as shown in Fig. 2(c). Then, the ends of the joint rebars 31 and the horizontal rebars 43 are connected to each other with joints 44.

[0026] After that, formwork (not shown) is installed at positions corresponding to the joint 3 and the end beam 41, and cast-in-place concrete is poured inside the formwork to form the joint 3 and the end beam 41 as shown in Fig. 2(d). If the column 2 is made of cast-in-place concrete, the concrete for the column 2 below the joint 3, the joint 3, and the end beam 41 may be poured at the same time.

[0027] Thereafter, as shown by the arrow in Figure 2(d), the column 2 is dropped from above the joint 3, and the protruding portion of the reinforcing bar 21 protruding from the joint 3 is inserted into the lower part of the sleeve 24 of the column 2. The joint structure 1 shown in Figure 1 is constructed by filling the sleeve 24 with a filler such as mortar. Note that the column 2 above the joint 3 can also be formed from cast-in-place concrete, as described above. In this case, the sleeve 24 of the column 2 can be omitted.

[0028] As described above, according to this embodiment, a frame with excellent strength can be realized by dividing the beam 4 into the end beam 41 and the intermediate beam 42, using environmentally friendly and aesthetically pleasing wood material for the intermediate beam 42, and using reinforced concrete for the joints 3 and the end beam 41. For example, by allowing the end beam 41 to exhibit the toughness performance of reinforced concrete, a frame with excellent toughness that undergoes bending yielding prior to repeated loads during an earthquake can be realized.

[0029] As for the intermediate beam 42, a precast member (intermediate beam 42) fabricated in advance at a factory or the like can be dropped in from above and installed, and the joint rebars 31 of the joint 3 can be connected to the horizontal rebars 43 of the intermediate beam 42 with joints 44, so there is no need to move the intermediate beam 42 in the direction of its material axis when constructing it, improving workability. In addition, because the joint 3 is made of reinforced concrete, it is possible to avoid the problem of rebars being inserted perpendicular to the grain of the wooden members, as mentioned above.

[0030] Furthermore, by locating the joint 44 at the position of the end beam 41, it is possible to avoid connections between the rebars at the joint 3 where the rebars are densely arranged, while realizing hinge relocation that shifts the position at which the frame yields in bending toward the center of the beam. This improves the performance of the joint structure 1 and increases the strength of the entire frame.

[0031] However, the present invention is not limited to the above embodiment. For example, as shown in Fig. 3(a) in a cross section similar to that of Fig. 1(b), the end beam 41a may be a composite structure of an exterior wood 411 and concrete 412.

[0032] The exterior timber 411 is a plank-shaped wooden material arranged to cover both sides and the bottom of the end beam 41a, and the inside of the plank is filled with concrete 412. During construction, in the process of forming the joint 3 and the end beam 41a (see FIG. 2(d)), the exterior timber 411 is placed as a form in the area of ​​the end beam 41a, and concrete 412 is poured inside the plank.

[0033] The exterior timber 411 functions as shear reinforcement for the end beams 41a and as formwork when pouring the concrete 412, and also serves as a fuel that contributes to the fire resistance of the internal reinforced concrete. In addition, the concrete 412 maintains the strength of the members, while leaving the wood exposed, allowing the original beauty of wooden construction to be expressed.

[0034] The exterior timber 411 can be made of laminated timber, CLT, BP material, etc. The material and thickness of the exterior timber 411 are determined so that it has sufficient in-plane strength to function as a shear reinforcement material, can resist the out-of-plane pressure when pouring the concrete 412, and contributes to fire resistance as a burnable material. By constructing the inside of the exterior timber 411 out of reinforced concrete, the fire resistance of the exterior timber 411 (in an unburned state) is not particularly necessary, and fireproof coating, etc. is not necessary, which reduces the construction effort and cost.

[0035] Furthermore, as shown in Fig. 3(b), the joint 3a may be a composite structure of exterior timber 32 and concrete 33. Wood materials such as laminated timber, CLT, and BP material are used as the exterior timber 32, and are arranged so as to cover all sides of the joint 3a except for the boundary with the end beam 41. During construction, in the process of forming the joint 3a and the end beam 41 (see Fig. 2(d)), the exterior timber 32 is arranged as a formwork at the joint 3a, and concrete 33 is filled inside. The exterior timber 32 has the same function and role as the exterior timber 411 described above.

[0036] Alternatively, as shown in FIG. 3(c), both the joint 3a and the end beam 41a may be made of a composite structure of exterior timber 32, 411 and concrete 33, 412.

[0037] In addition, in both cases described in Figures 1 and 3, the joints 3, 3a can be integrated with the column 2 below them to form a precast member. Figure 4 shows one example, in which the reinforced concrete joint 3 and the column 2 below it are integrated into a single precast member, allowing the column 2 and joint 3 to be installed together. In this case, concrete is poured on-site only at the positions of the end beams 41, 41a.

[0038] 1(b), the beam 4 may be a double beam, and a pair of beams 4 may be placed on either side of the joint 3 with a gap in the beam width direction. This allows the cross section of the beam 4 to be smaller, and the cost required for the beam 4 to be reduced. The beam width direction is a direction perpendicular to the material axis direction of the beam 4 in a plan view, and corresponds to the up-down direction in FIG. 5.

[0039] In this embodiment, the pillars 2 are provided above and below the joint 3, but there are also cases where the pillars 2 are provided only above or below the joint 3. In this embodiment, the beams 4 are provided on the left and right of the joint 3, but there are also cases where the beams 4 are provided only to the left or right of the joint 3. Furthermore, the beams 4 are not only provided in the left-right direction of the joint 3 (corresponding to the left-right direction in FIG. 1(b)), but also in some cases in the front-rear direction (corresponding to the up-down direction in FIG. 1(b)) that is perpendicular to the left-right direction in a plan view, and in this case too, a beam 4 having a similar configuration can be provided in front of or behind the joint 3, or both.

[0040] In this embodiment, the column 2 is made of reinforced concrete, which is excellent in terms of strength and fire resistance, but the column 2 is not limited to this. Below, examples in which the column 2 has a different structure will be described as the second and third embodiments. In the second and third embodiments, configurations that are different from the first embodiment will be mainly described, and similar configurations will be given the same reference numerals in the figures and the like and will not be described. Furthermore, the configurations described in each embodiment, including the first embodiment, can be combined as necessary.

[0041] [Second embodiment] 6(a) and (b) are diagrams showing a joint structure 1a according to a second embodiment of the present invention, in which Fig. 6(a) is a diagram showing the joint structure 1a as seen from the front, and Fig. 6(b) is a diagram showing a horizontal cross section taken along line BB in Fig. 6(a).

[0042] The joint structure 1a of this embodiment differs from the first embodiment in that the pillar 2a is a composite structure made of exterior timber 22 and concrete 23.

[0043] The exterior wooden pieces 22 are planar wooden materials and are arranged to cover all sides of the pillars 2a. Concrete 23 is filled inside the exterior wooden pieces 22. As in the first embodiment, vertical reinforcing bars 21 are embedded inside the concrete 23, and their lower ends are inserted into the upper parts of sleeves 24 embedded in the lower ends of the concrete 23.

[0044] The exterior timber 22 can be made of laminated timber, CLT, BP material, etc. As with the exterior timber 411, the exterior timber 22 functions as a shear reinforcement for the columns 2a and as a formwork when pouring the concrete 23, and also serves as a burner that contributes to the fire resistance of the internal reinforced concrete. In addition, the concrete 23 maintains the strength of the members, while leaving the wood exposed, allowing the original beauty of wooden construction to be expressed.

[0045] The method of constructing the joint structure 1a is basically the same as that of the first embodiment, and the same effects as those of the first embodiment can be obtained in this embodiment. Note that, although the pillar 2a is a precast member in this embodiment, the pillar 2a may be constructed on-site by arranging reinforcing bars 21, etc., assembling the exterior timber 22, pouring concrete 23, etc. at the construction site of the pillar 2a.

[0046] In addition to the reinforcing bars 21, hoops for shear reinforcement can be provided inside the concrete 23 so as to surround the reinforcing bars 21 in a plan view. When the concrete 23 is poured inside the exterior timbers 22 in a factory or the like to fabricate the columns 2a, the exterior timbers 22 that face each other in a plan view are connected by separators (not shown) to resist the out-of-plane pressure applied to the exterior timbers 22 from the concrete 23, and these separators can also be used as shear reinforcement.

[0047] In addition, by providing a shear stress transmission mechanism such as a connector (not shown) that protrudes from the inner surface of the exterior wooden piece 22 into the concrete 23, the integrity of the exterior wooden piece 22 and the concrete 23 can be improved.

[0048] In this embodiment, as explained in Fig. 3(a)-(c), either or both of the joint 3 and the end beam 41 can be made of a composite structure of exterior wood and concrete. In any case, including the joint structure 1a in Fig. 6, the joints 3, 3a can be integrated with the column 2a below to form a precast member. Fig. 7(a) shows the joint 3 and column 2a of reinforced concrete construction as an integrated precast member, while Fig. 7(b) shows the joint 3a having a composite structure as a precast member integrated with the column 2a.

[0049] 8, the intermediate beam 42a may be a beam-shaped precast member having a composite structure of exterior timber 421 and concrete 422, similar to the column 2a. The exterior timber 421 is a plank-shaped wooden material, and is placed so as to cover both sides and the bottom of the intermediate beam 42a, with the inside being filled with concrete 422. As the exterior timber 421, laminated timber, CLT, BP material, etc. are used, and it has the same function and role as the exterior timber 411 described above.

[0050] [Third embodiment] 9 is a diagram showing a joint structure 1b according to a third embodiment of the present invention, as viewed from the front. The joint structure 1b of this embodiment differs from the first embodiment in that the pillar 2b is a wooden member and the entire structure is made of wood material.

[0051] The wooden material may be laminated wood or the like, but is not limited to this. Although not shown in the figure, a flame-retardant layer is provided on all sides of the column 2b to ensure the fire resistance of the column 2b. The flame-retardant layer is made by impregnating a flame-retardant agent into the wooden material, but is not limited to this and may be made of other materials having fire resistance. In some cases, the flame-retardant layer may be omitted.

[0052] A part of the vertical reinforcing bar 25 is embedded in the upper end of the column 2b. For example, a part of the reinforcing bar 25 is inserted into a hole (not shown) formed in the upper end of the column 2b in the material axis direction, and the hole is filled with a filler material such as mortar. This makes it possible to embed and fix a part of the reinforcing bar 25 in the upper end of the column 2b. The remaining part of the reinforcing bar 25 protrudes upward from the column 2b, penetrates the joint 3 vertically, and protrudes further upward from the joint 3.

[0053] On the other hand, a hole 26 for joining the column 2b is provided at the lower end of the column 2b. The protruding portion of the reinforcing bar 25 protruding from the joint 3 is inserted into the hole 26 of the column 2b above the joint 3, and the hole 26 is filled with a filler material (not shown) such as mortar, thereby joining the column 2b above the joint 3 to the joint 3.

[0054] The method of constructing the joint structure 1b is basically the same as that of the first embodiment, and when providing the pillar 2b above the joint 3, the pillar 2b is dropped from above as shown in Fig. 10. As described above, the protruding portion of the reinforcing bar 25 protruding upward from the joint 3 is inserted into the hole 26 of the pillar 2b, and the hole 26 is filled with a filler, thereby joining the pillar 2b above the joint 3.

[0055] In this embodiment, the same effects as those of the first embodiment can be obtained. In addition, by proactively using wood materials for the columns 2b, a structure that is excellent in terms of the environment and design can be provided.

[0056] In this embodiment, as described in Figs. 3(a) to (c), either or both of the joint 3 and the end beam 41 can be made of a composite structure of wood material and concrete. In any case, including the joint structure 1b in Fig. 9, the joints 3, 3a can be integrated with the column 2b below to form a precast member. For the joint 3a having a composite structure, as shown in Fig. 11, only the column 2b and the outer wooden material 32 of the joint 3a can be made into an integrated precast member, and the joint reinforcing bar 31 and concrete 33 of the joint 3a can be constructed on-site. This is also true for the column 2a in the second embodiment.

[0057] Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to the above examples. It is clear that a person skilled in the art can come up with various modified or altered examples within the scope of the technical ideas disclosed in this application, and it is understood that these also naturally belong to the technical scope of the present invention. [Explanation of symbols]

[0058] 1, 1a, 1b: Joint structure 2, 2a, 2b: Pillar 3, 3a: Joint 4:Beam 21, 25: Reinforced concrete 22, 32, 411, 421: Outer timber 23, 33, 412, 422: Concrete 24: Sleeve 26: Hole 31: Joint rebar 41, 41a: End beam 42, 42a: Intermediate beam 43: Horizontal rebar 44: Joint

Claims

1. A joint structure in which a column and a beam are joined via a joint having a concrete portion, The beam has an end beam provided on a side surface of the joint and an intermediate beam continuous with the end beam, The intermediate beam is a beam-shaped precast member made of wood material, and a horizontal reinforcing bar is provided protruding from the end portion in the material axis direction toward the joint portion, The end beam has a concrete portion made of cast-in-place concrete; A horizontal joint reinforcing bar is embedded so as to straddle the joint and the concrete portion of the end beam, A joint structure characterized in that the ends of the horizontal reinforcing bar and the joint reinforcing bar are connected by a joint within the concrete portion of the end beam.

2. 2. The joint structure according to claim 1, wherein the column is a member of reinforced concrete construction.

3. 2. The joint structure according to claim 1, wherein the pillar has a composite structure in which concrete is filled inside the outer timber shell.

4. 2. The joint structure according to claim 1, wherein the pillar is a wooden member.

5. 2. The joint structure according to claim 1, wherein the joint has a composite structure in which concrete is filled inside the outer timber shell.

6. 2. The joint structure according to claim 1, wherein the end beam has a composite structure in which concrete is filled inside the outer timber shell.

7. When constructing the joint structure according to any one of claims 1 to 6, After the intermediate beam is dropped from above into the construction location of the intermediate beam, the ends of the joint reinforcing bars and the horizontal reinforcing bars are connected to each other by the joints, A method for constructing a joint structure, characterized by subsequently pouring concrete for the end beam.

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