Joint structure

Abstract

To provide a joining structure, etc., between precast members which are easy to construct and does not cause damage or the like to the members.SOLUTION: A joining structure 10 joins half-PCa members 1 used in the construction of a structure to each other. The half PCa member 1 is provided with a buried form 2 of the structure and a main steel material 3. A joint material 4 is provided at the end of the buried form 2 of one half PCa member 1-1, and the main steel material 3 of the half PCa member 1-1 is arranged inside the joint material 4. The main steel material 3 protruding from the buried form 2 of the other half PCa member 1-2 is arranged inside the joint material 4, and the inside of the joint material 4 is filled with concrete C.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a joint structure between precast members. [Background technology]

[0002] Half-precast members (hereinafter referred to as half-PCa members), which integrate the main steel material of a structure with the buried formwork, have high rigidity themselves, making it possible to omit support work on the underside and sides of the formwork, which is effective in improving productivity when constructing a structure.

[0003] When half-PCa components are arranged side by side, the main steel materials of adjacent half-PCa components are generally joined together using friction joints or welded joints, but shear reinforcement bars and other components are densely arranged at the joints, making it difficult to carry out the joining work on site.

[0004] In response to this, Patent Document 1 describes a joint structure in which a lap joint is formed in the main steel material in the same manner as a lap joint in rebar, utilising notches in the precast members, and pouring filler concrete into the joint, making it easy to join precast members together. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6375079 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the joint structure described in Patent Document 1, the cross section of the precast members is missing due to the notch, so if loads such as the weight of materials and equipment act on the joints during construction, the precast members may be damaged. In order to prevent damage to the precast members, it is necessary to increase the thickness and strength of the members, but this is costly and uneconomical, and the increased weight of the members reduces workability.

[0007] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a joint structure between precast members which is easy to install and does not cause damage to the members. [Means for solving the problem]

[0008] To achieve the above-mentioned objectives 1. The invention relates to a joint structure for joining precast members, which are used when constructing a structure and include an embedded formwork and a reinforcing material for the structure, in which a joint material is provided at an end of the embedded formwork of one precast member, the reinforcing material of the precast member is disposed inside the joint material, the reinforcing material protruding from the embedded formwork of the other precast member is disposed inside the joint material, and a filler is filled inside the joint material. The joint member has a bottom plate and a pair of side plates protruding from both sides of the bottom plate, and the reinforcing member is disposed between the pair of side plates of the joint member. The joining structure is characterized by the above. The second invention is a joining structure used when constructing a structure to join precast members which have an embedded formwork for the structure and a reinforcing material, characterized in that a joint material is provided at the end of the embedded formwork of one precast member, the reinforcing material of the precast member is disposed inside the joint material, the reinforcing material protruding from the embedded formwork of the other precast member is disposed inside the joint material, a filling material is filled inside the joint material, the joint material is cylindrical, and the reinforcing material is inserted inside the joint material.

[0009] In the present invention, a joint between the reinforcing materials of one precast member is established simply by placing the reinforcing material of the other precast member inside the joint material installed at the end of the buried formwork of the other precast member and filling it with filling material, so that construction is easy with less on-site work. Also, since the reinforcing material is placed inside the joint material, there is no need to cut out the end of the buried formwork, and there is no risk of damage to the end of the buried formwork.

[0010] It is desirable that the joint material be groove-shaped, with a portion of it being embedded in the embedded formwork of one of the precast members and the other portion being open in the normal direction of the embedded formwork. By embedding a part of the joint material in the buried formwork of one of the precast members, the end of the buried formwork can be reinforced by the joint material, preventing damage to the end of the buried formwork. Also, by forming the joint material into a groove shape and leaving the other part open in the normal direction of the buried formwork, the other precast member can be positioned so that the reinforcing material is inserted into the joint material from the open surface, making on-site work easier. In addition, the filling material has good filling properties, improving the quality of the joint part.

[0011] The reinforcing material may be provided with an uneven portion. It is also preferable that the reinforcing material is provided with an end plate. This improves the adhesion between the reinforcing material and the filler, improving the stress transmission performance of the joint. Also, by providing end plates to the reinforcing material, the fixing force of the reinforcing material to the filler can be increased, preventing it from slipping out of the joint.

[0012] The inner surface of the joint material may be provided with an uneven portion. before Note A pair It is also preferable that the spacing between the side plates becomes smaller from the middle to the end of the joint material in the component axial direction of the reinforcing material. Furthermore, it is also preferable that end plates are provided at the end of the joint material in the component axial direction of the reinforcing material to prevent the filler from slipping out. This improves the stress transmission performance of the joint. Also, by providing the joint material with the end plate, it is possible to prevent the concrete inside the joint material from slipping out when a pull-out force acts on the reinforcing material.

[0013] The joint material is ,before Reinforcement section for reinforcing the side panel against outward bulging of It is also desirable to have For example, if a reinforcing material with unevenness on the surface facing the side plate of the joint material is used, when a pull-out force acts on the reinforcing material, the unevenness tries to overcome the filler, generating a force that pushes the filler outward, which may cause the side plate of the joint material to bulge outward. In this way, if there is a risk that the side plate will bulge outward when a pull-out force acts on the reinforcing material, a reinforcing part can be provided in the joint material to prevent the side plate from bulging and ensure stress transmission performance.

[0014] It is also desirable that the joint material have a side plate disposed between the multiple reinforcements of one of the precast members, and a side plate disposed on the outside of the multiple reinforcements. In this case, the side panels between the reinforcing members are subjected to the pushing force of the filler from both sides, and these forces are offset, so that no bulging occurs in the side panels. Effect of the Invention

[0015] According to the present invention, it is possible to provide a joint structure between precast components which is easy to install and does not cause damage to the components. [Brief description of the drawings]

[0016] [Figure 1] A diagram showing a joint structure 10 of a half PCa member 1. [Diagram 2] A diagram showing a joint structure 10 of a half PCa member 1. [Diagram 3] A diagram showing the state after concrete C has been poured. [Figure 4] FIG. 4 is a diagram showing a modified example of the arrangement of the main steel material 3 and the joint material 4. [Diagram 5] 11A and 11B are diagrams showing modified cross sections of the joint material 4. [Figure 6] FIG. 4 is a diagram showing a modified example of the main steel material 3. [Figure 7] FIG. 4 is a diagram showing a modified example of the joint material 4. [Figure 8] 4A and 4B are diagrams illustrating a reinforcing portion of a side plate 41 and a joint material 4a. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0018] Fig. 1(a) is a diagram showing a joint structure 10 according to an embodiment of the present invention. The joint structure 10 joins half PCa members 1 (1-1, 1-2) arranged side by side in the horizontal direction. Each half PCa member 1 (1-1, 1-2) to be joined is shown in Fig. 1(b).

[0019] The half PCa member 1 is a precast member used when constructing a structure such as a slab, and includes an embedded formwork 2 for the structure and a main steel member 3. In addition, a joint member 4 is provided at the end of the embedded formwork 2 of one half PCa member 1-1 of the half PCa members 1 to be joined, on the side of the other half PCa member 1-2.

[0020] The buried formwork 2 is a plate-shaped concrete member, and a structure such as a slab is constructed by pouring concrete C onto the buried formwork 2 as a bottom formwork.

[0021] The main steel materials 3 are reinforcing materials for the structure, and are provided on the upper surface of the buried formwork 2. The main steel materials 3 are, for example, flat steel bars, and a plurality of the main steel materials 3 are arranged in parallel with the plate surfaces in the vertical direction. Note that the main steel materials 3 are not limited to flat steel bars, and various types of steel materials can be used, including other shaped steel bars such as H-shaped steel bars, angle steel bars, and channel steel bars.

[0022] Of both ends of the main steel material 3 of one of the half PCa members 1-1 described above, the end located on the other half PCa member 1-2 side is disposed within a joint material 4. The joint materials 4 are provided corresponding to each of the multiple main steel materials 3 of the half PCa member 1-1.

[0023] Furthermore, of both ends of the main steel material 3 of the other half PCa component 1-2, the end located on the side of one half PCa component 1-1 protrudes from the end face of the half PCa component 1-1 side of the buried formwork 2. This end is disposed within the joint material 4, and within the joint material 4, the main steel materials 3 of both half PCa components 1 are disposed so that their component axial directions are aligned in a straight line.

[0024] 2(a) and (b) are diagrams showing a cross section of the buried formwork 2 in the thickness direction of the joint structure 10. FIG. 2(a) is a cross section along the member axial direction of the main steel material 3, and FIG. 2(b) is a cross section in the direction orthogonal to the axis of the main steel material 3 along line AA in FIG. 2(a). The direction orthogonal to the axis of the main steel material 3 is a direction perpendicular to the member axial direction of the main steel material 3 in a plane. FIG. 2(c) is a diagram showing a horizontal cross section of the joint structure 10 at the height of the main steel material 3. Note that FIGS. 2(a) to 2(c) show the state before concrete C is poured.

[0025] The joint material 4 is a channel-shaped steel material having a side plate 41 and a bottom plate 42, and its cross section is concave. As shown in Fig. 2(b), part of the joint material 4 is embedded in the buried formwork 2, and the other part is exposed on the upper surface of the buried formwork 2 and is open in the normal direction of the buried formwork 2 (corresponding to the up-down direction in Fig. 2(b)). The joint material 4 is installed so that its axial direction is aligned with the component axial direction of the main steel material 3.

[0026] In this embodiment, after one half PCa member 1-1 is installed, the other half PCa member 1-2 is moved from above as shown by arrow a in Figure 1(b), and the end of the main steel material 3 protruding from the half PCa member 1-2 is inserted into the inside of the joint material 4 from the open surface of the joint material 4, and the main steel materials 3 of the half PCa members 1-1 and 1-2 are positioned inside the joint material 4 so that their component axial directions are in a straight line.

[0027] At this time, the end faces of the embedded formwork 2 of the half PCa members 1-1 and 1-2 abut against each other as shown in Figure 2(a), and then concrete C is poured onto the embedded formwork 2 of the half PCa members 1-1 and 1-2 to construct a structure such as a slab.

[0028] Fig. 3 shows the state after pouring of the concrete C in the same cross section as Fig. 2(c). In this embodiment, the inside of the joint material 4 is also filled with concrete C as a filler, and a joint portion between the main steel materials 3 of the half PCa members 1-1, 1-2 is formed inside the joint material 4. When a pull-out force acts on the main steel materials 3 in this joint portion, stress (shear stress) is transmitted between the main steel materials 3 via the concrete C and the joint material 4.

[0029] In this embodiment, the joint between the main steel materials 3 of both half PCa members 1-1 and 1-2 is established simply by placing the main steel materials 3 of the half PCa member 1-2 inside the joint material 4 installed at the end of the buried formwork 2 of the other half PCa member 1-1 and filling it with concrete C, so that construction is easy and there is little on-site work required. Also, since the main steel materials 3 are placed inside the joint material 4, there is no need to notch the end of the buried formwork 2, and there is no risk of damage to the end of the buried formwork 2.

[0030] In this embodiment, by embedding a part of the joint material 4 in the buried formwork 2, the end of the buried formwork 2 can be reinforced by the joint material 4, and damage to the end of the buried formwork 2 can be prevented. By forming the joint material 4 in a groove shape and leaving the other part open in the normal direction of the buried formwork 2, the half PCa member 1-2 can be arranged so that the main steel material 3 is inserted into the inside of the joint material 4 from the open surface of the joint material 4, making on-site work easier. In addition, the filling property of the concrete C is also good, so the quality of the joint portion is improved.

[0031] However, the present invention is not limited to the above embodiment. Below, modified examples of the joint structure 10 of the present invention will be described, but the configurations described below and the configurations described in the above embodiment can be used in combination as necessary.

[0032] For example, in this embodiment, main steel materials 3 such as flat steel bars are provided in the buried formwork 2 as reinforcing materials for the structure, but instead, reinforcing bars or the like may be provided as reinforcing materials. Furthermore, the structure constructed using the half PCa members 1 may be a wall-shaped or column-shaped structure. In this case, it is also possible to arrange the half PCa members 1 side by side in the vertical direction and form joints using joint materials 4 or the like between the main steel materials 3 of the upper and lower half PCa members 1.

[0033] In this embodiment, the concrete C is filled into the joint material 4 when the concrete C of the structure is poured, and there is no need to fill the joint material 4 with a filler in a separate process. However, it is possible to fill the joint material 4 with a filler separately, and the filler is not limited to concrete. For example, a cement-based material other than concrete can be used, and a filler other than a cement-based material can be used. In particular, if the material expands when hardened, the frictional force acting on the main steel material 3 increases as the joint material 4 restrains the expansion pressure, which can contribute to the transmission of stress (shear stress). In addition, a filler that can be expected to have adhesive strength with the joint material 4 and the main steel material 3 is also suitable.

[0034] In addition, in this embodiment, a portion of the joint material 4 is embedded in the buried formwork 2, but it is also possible to place and fix the joint material 4 on the upper surface of the buried formwork 2, without embedding it in the buried formwork 2.

[0035] Furthermore, the main steel materials 3 of the half PCa members 1-1 and 1-2 may be placed in any position inside the joint material 4. For example, as shown in Fig. 4(a), they may be placed parallel to one another inside the joint material 4, allowing stress transmission between the main steel materials 3 via concrete C. Furthermore, as shown in Fig. 4(b), the positions of the joint materials 4 in the component axial direction of the main steel materials 3 may be changed, and some of the joint materials 4 may be shifted from the other joint materials 4 and placed in a staggered pattern, which can alleviate stress concentration at the joint locations.

[0036] The cross-sectional shape of the joint material 4 is not particularly limited, and may be any shape that can accommodate the end of the main steel material 3 inside. For example, the bottom plate 42 of the joint material 4 may be U-shaped as shown in FIG. 5(a) or V-shaped as shown in FIG. 5(b). By making the cross section of the joint material 4 convex downward, bleeding that occurs on the bottom surface of the joint material 4 can be suppressed when the buried formwork 2 is manufactured with concrete. In some cases, the top surface of the joint material 4 may be closed, and the cross section of the joint material 4 may be cylindrical. However, in this case, it is necessary to move the half PCa member 1-2 laterally to insert the main steel material 3 into the joint material 4, which makes construction difficult.

[0037] Also, for the main steel material 3, the end of the main steel material 3 inserted into the joint material 4 can be provided with an uneven portion on the surface facing the side plate 41 of the joint material 4. The uneven portion can be formed by welding a bar such as a reinforcing bar to the surface of the main steel material 3, by groove processing on the surface of the main steel material 3, or by providing a stud 31 as an uneven portion as shown in FIG. 6(a), which can improve the adhesion of the concrete C and enhance the stress transmission performance of the joint part. The uneven portion of the main steel material 3 is not limited to this, and for example, a perforated plate 32 can be provided as shown in FIG. 6(b). Also, holes can be provided in the end of the main steel material 3 itself, and the same effect can be obtained. Furthermore, it is possible to provide an end plate 33 at the end of the main steel material 3 as shown in FIG. 6(c), which increases the fixing force of the main steel material 3 to the concrete C, thereby preventing the main steel material 3 from coming out of the joint part due to the pulling force acting on the main steel material 3, and ensuring stress transmission between the main steel materials 3.

[0038] As shown in Fig. 7(a), the joint material 4 can also have an uneven portion on the inner surface of its side plate 41, which can improve the stress transmission performance of the joint portion as described above. In Fig. 7(a), studs 43 are provided as the uneven portion, but the uneven portion is not particularly limited, and as in the above, the uneven portion can be provided by welding rebar to the side plate 41 of the joint material 4 or by processing grooves instead of the studs 43, or a perforated plate can be provided. Also, holes can be provided in the joint material 4 itself.

[0039] 7(b), the distance between the side plates 41 located on both sides of the main steel material 3 can be made smaller from the middle to the ends of the joint material 4 in the axial direction of the main steel material 3. This makes it easier to transmit the shear stress generated in the concrete C when a pull-out force acts on the main steel material 3 to the side plates 41, and prevents the concrete C from being pulled out of the joint material 4, improving the stress transmission performance of the joint portion.

[0040] 7(c), it is also possible to provide end plates 44 at both ends of the joint material 4 in the component axial direction of the main steel material 3, and by closing the ends of the joint material 4 with the end plates 44, it is possible to prevent the concrete C inside the joint material 4 from escaping when a pull-out force acts on the main steel material 3, and to reliably transmit stress between the main steel materials 3. Reference numeral 441 denotes a slit provided in the end plate 44 to allow the main steel material 3 to pass through.

[0041] 7(a)-(c), the main steel material 3 is provided with a stud 31, but if the main steel material 3 is provided with uneven parts such as the studs 31 or end plates 33, when a pull-out force acts on the main steel material 3, the uneven parts of the main steel material 3 will try to overcome the concrete C, generating a force that pushes the concrete C inside the joint material 4 toward the side plate 41, which may cause the side plate 41 of the joint material 4 to bulge outward and impair the stress transmission performance. In this way, if there is a risk that the side plate 41 will bulge outward when a pull-out force acts on the main steel material 3, it is also desirable to provide the joint material 4 with a reinforcing part for reinforcing the side plate 41 against the outward bulging, which may reduce the cost by making the side plate 41 thinner.

[0042] For example, as shown in Fig. 8(a), the side plates 41 of adjacent joint materials 4 are connected to each other by a connecting plate 45 (reinforcement portion) arranged in a direction perpendicular to the axis of the main steel material 3, thereby reinforcing the side plates 41 of the joint materials 4 and preventing the side plates 41 from expanding. Also, as shown in Fig. 8(b), it is possible to arrange a triangular reinforcing rib 46 (reinforcement portion) at the corners of the side plate 41 and the bottom plate 42 and fix the reinforcing rib 46 to the side plate 41 and the bottom plate 42, which also reinforces the side plate 41 and prevents it from expanding. A similar reinforcing rib 46 can also be provided on the outside of the side plate 41. The shape of the reinforcing rib 46 is not particularly limited.

[0043] 8(c), it is also possible to connect the side plates 41 of the joint material 4 with connecting members 47 (reinforcements) in a direction perpendicular to the axis of the main steel material 3. The connecting members 47 are, for example, bolts or threaded rebars, and by bridging the connecting members 47 between the notches 411 provided in both side plates 41 and tightening nuts from the outside of the side plates 41, the tensile resistance of the connecting members 47 can prevent the side plates 41 from swelling.

[0044] Alternatively, as shown in Fig. 8(d), the joint material 4a may have a side plate 41a arranged between adjacent main steel members 3 and a side plate 41b arranged on the outside of the main steel members 3. In this case, the extrusion force of the concrete C acts from the main steel members 3 on both sides of the side plate 41a toward the side plate 41a, and these extrusion forces are offset, so that the side plate 41a does not bulge. Although not shown in particular, it is possible to prevent the bulging of the outer side plate 41b by using reinforcing parts such as the reinforcing rib 46 in Fig. 8(b) or the connecting member 47 in Fig. 8(c).

[0045] 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 such an example. 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 such examples also naturally belong to the technical scope of the present invention. [Explanation of symbols]

[0046] 1, 1-1, 1-2: Half PCa member 2: Buried formwork 3: Main steel material 4, 4a: Joint material 10:Joint structure 31, 43: Stud 32: Perforated plate 33: End plate 41, 41a, 41b: Side plate 42: Bottom plate 44: End plate 45: Connecting plate 46: Reinforcement rib 47: Connecting material

Claims

1. A joint structure for joining precast members having a buried formwork and a reinforcing material of a structure, which is used when constructing a structure, A joint material is provided at an end of the embedded formwork of one precast member, and the reinforcing material of the precast member is disposed inside the joint material; The reinforcing member protruding from the embedded formwork of the other precast member is disposed inside the joint member; A filler material is filled inside the joint material, A joint structure characterized in that the joint material has a bottom plate and a pair of side plates protruding from both sides of the bottom plate, and the reinforcing material is positioned between the pair of side plates of the joint material.

2. A joint structure for joining precast members having a buried formwork and a reinforcing material of a structure, which is used when constructing a structure, A joint material is provided at an end of the embedded formwork of one precast member, and the reinforcing material of the precast member is disposed inside the joint material; The reinforcing member protruding from the embedded formwork of the other precast member is disposed inside the joint member; A filler material is filled inside the joint material, A joint structure characterized in that the joint material is tubular and the reinforcing material is inserted inside the joint material.

3. The joint structure described in claim 1, characterized in that the joint material is groove-shaped, a portion of which is embedded in the embedded formwork of one precast member, and the other portion is open in the normal direction of the embedded formwork.

4. 4. The joint structure according to claim 1, wherein the reinforcing material is provided with an uneven portion.

5. 5. The joint structure according to claim 1, wherein the reinforcing material is provided with an end plate.

6. 6. The joint structure according to claim 1, wherein an inner surface of the joint material is provided with projections and recesses.

7. A joint structure as described in claim 1 or claim 3, characterized in that the distance between the pair of side plates becomes smaller as it moves from the middle to the end of the joint material in the component axial direction of the reinforcing material.

8. 8. The joint structure according to claim 1, wherein an end plate is provided at an end of the joint material in the axial direction of the reinforcing material to prevent the filler material from slipping out.

9. 4. The joint structure according to claim 1, wherein the joint material has a reinforcing portion for reinforcing the side plate against outward bulging.

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