Joining structure for concrete members, joining method for concrete members
The joint structure with notches and movable sleeves addresses assembly challenges in precast concrete members by facilitating easy alignment and connection, improving workability and reducing costs.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- CHIBA YOGYO
- Filing Date
- 2026-04-20
- Publication Date
- 2026-07-29
AI Technical Summary
Conventional joint structures for precast concrete members, such as box culverts, face challenges including obstacles during assembly, increased construction costs, and delays due to the need for heavy machinery and complex on-site formwork, which hinder efficient joining and increase costs.
A joint structure where notches are formed on the side surfaces of concrete members, with reinforcing bars extending to facing surfaces, and a movable sleeve is attached to facilitate easy alignment and connection of reinforcing bars, allowing for efficient on-site assembly without the need for complex machinery or additional space.
This approach enhances workability, prevents construction delays, and reduces costs by simplifying the joining process of precast concrete members, enabling efficient assembly even in confined spaces.
Smart Images
Figure 2026123098000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a joining structure and a joining method for concrete members that make up concrete products such as box culverts.
Background Art
[0002] As is well known, when constructing large concrete products, precast concrete technology is used due to transportation and construction constraints.
[0003] Particularly for box culverts, enlargement is desired. It is not uncommon to prefabricate the concrete members (precast members) that make up the box culvert in a factory in advance by dividing them, and then join the concrete members at the construction site or factory to construct the box culvert as a precast product.
[0004] In FIG. 1, reference numeral 1 indicates a box culvert constructed as a precast product. This box culvert 1 is divided into concrete members T1 to T5 that form the top slab T, concrete members B1 to B5 that form the bottom slab B, concrete members W1 and W3 that form the left and right side walls, and W2 that forms the intermediate wall. Hereinafter, they will be referred to as divided blocks T1 to T5, B1 to B5, and W1 to W3, respectively.
[0005] As a joining structure (joining method) for each of the divided blocks T1 to T5, B1 to B5, and W1 to W3, a method is adopted in which the reinforcing bar 3 of the other joining part is inserted into the sleeve 2 embedded in one joining part to be joined, and then a filler is filled in the gap in the sleeve 2. Here, the positions of the sleeve 2 and the reinforcing bar 3 are determined at the design stage as to which joining part to embed them in. As techniques of the same kind as such a method, Patent Documents 1 and 2 are known.
Prior Art Documents
Patent Documents
[0006]
Patent Document 1
[0007] Conventional joint structures (joining methods) such as those described in Patent Documents 1 and 2 have the following problems because the reinforcing bar 3 of one joint is inserted into a sleeve 2 embedded in the other joint.
[0008] (1) In Figure 2(a), 1a shows box culvert under construction, i.e., box culvert 1 in a state where the divided blocks T1, T2, T4, and T5 have not yet been set. Here, sleeves 2 and reinforcing bars 3 are provided at the joints (each end) of each divided block T1-T5, B1-B5, and W1-W3.
[0009] In this case, as shown in Figure 2(a), first, the reinforcing bars 3 at one end of each of the divided blocks T2 and T4 are inserted into the sleeves 2 at the left and right ends of the divided block T3. Next, the reinforcing bars 3 at the other ends of the divided blocks T2 and T4 are inserted into the sleeves 2 at one end of each of the divided blocks T1 and T5. After that, the reinforcing bars 3 at the upper ends of the divided blocks W1 and W3 are inserted into the sleeves 2 at the other ends of the divided blocks T1 and T5.
[0010] (2) However, as shown in Figure 2(b), when moving the divided block T1 laterally (P direction) using a crane or the like to insert the reinforcing bar 3 at the other end of the divided block T2 into the sleeve 2 at one end, the reinforcing bar 3 at the upper end of the divided block W1 may become an obstacle, as shown in section S1 (dashed line), making it difficult to join the divided block T1.
[0011] Similarly, as shown by arrow Q, when lowering the divided block T5 using a crane or the like and inserting the reinforcing bar 3 at the upper end of the divided block W3 into the sleeve 2 at the other end of the divided block T5, the reinforcing bar 3 at the other end of the divided block T4 may become an obstacle, as shown in section S2 (dashed line), potentially making it difficult to join the divided block T5.
[0012] (3) As shown in Figure 3(a), a method has been proposed in which the divided blocks T2 and T4 are constructed by pouring concrete on site. According to this method, the space between the reinforcing bars 15 at the opposing ends of divided blocks T1 and T3 and the space between the reinforcing bars 15 at the opposing ends of divided blocks T3 and T5 are joined by a mechanical joint 16, and then concrete is poured for the portions of divided blocks T2 and T4.
[0013] In this case, not only is it necessary to install shoring in the internal space R, but formwork is also required when pouring concrete on site, which increases the number of work steps and could lead to delays in the construction period and increased costs.
[0014] (4) In addition, as shown in Figure 3(b), a method has been proposed in which the divided blocks T1 to T5 are integrated in advance as the A side, and similarly the divided blocks B1 to B5 and W1 to W3 are integrated as the B side. According to this method, the A side is lowered using heavy machinery and installed on the B side.
[0015] However, since side A integrates the divided blocks T1 to T5 into a single unit, it is heavy, requiring large heavy machinery during construction, which may lead to increased costs and restrictions on installation locations. In addition, when installing side A, it is necessary to insert the reinforcing bars 3 of divided blocks W1 to W3 into the sleeves 2 of divided blocks T1, T3, and T5, but depending on the product precision, insertion may be difficult, potentially worsening work efficiency.
[0016] (5) The present invention has been made to solve the above-mentioned conventional problems, and aims to improve work efficiency, prevent delays in construction, and reduce costs by facilitating the joining of divided blocks when constructing concrete products. [Means for solving the problem]
[0017] (1) One aspect of the present invention is a structure in which joints of concrete members constituting a concrete product are joined by facing each other, a notch formed on a side surface of the joint, and a reinforcing bar extending from a bottom surface of the notch to a facing surface of the joint, and is provided with a joint is movably attached to the reinforcing bar of one of the concrete members, and the joint is moved between the reinforcing bars and connected while the reinforcing bars of the two concrete members are facing each other.
[0018] (2) Another aspect of the present invention is a notch formed on a side surface of a joint of a concrete member constituting a concrete product, a reinforcing bar extending from a bottom surface of the notch to a facing surface of the joint, and is provided with a method of joining the joints by facing each other, a step of movably attaching a joint to the reinforcing bar of one of the concrete members, a step of facing the reinforcing bars of the two concrete members, and a step of moving the joint between the reinforcing bars and connecting it while in the facing state.
Effect of the Invention
[0019] According to the present invention, it is possible to improve workability, prevent a delay in the construction period, and suppress costs by facilitating the joining of divided blocks when constructing a concrete product.
Brief Description of the Drawings
[0020] [Figure 1] Divided image diagram of a box culvert. [Figure 2](a) is an image diagram of a conventional example for setting the divided blocks T1 to T4 in FIG. 1, and (b) is an image diagram for setting the divided blocks T1 and T5 from the directions of the arrows P and Q. [Figure 3] (a) is an image diagram of a conventional example for cast-in-place of the divided blocks T2 and T4, and (b) is an image diagram of a conventional example for integrally constructing with A side and B side. [Figure 4] (a) is an enlarged view of the joint of the divided blocks T1 and W1 in Example 1, and (b) is an enlarged view of the joint of the divided blocks T5 and W3. [Figure 5] (a) is an image diagram for horizontally moving the divided blocks T1 and T5 in the X1 and X2 directions, (b) is an image diagram showing the alignment of the same reinforcing bars and the movement of the mechanical joint in the Y1 and Y2 directions, and (c) is an image diagram after the completion of the same joint. [Figure 6] (a) is a detailed view of the C1 part in FIG. 5(a), (b) is the first detailed view of the C2 part in FIG. 5(b), (c) is the second detailed view, and (d) is a detailed view of the C3 part in FIG. 5(c). [Figure 7] (a) is a detailed view of the C4 part in FIG. 5(a), (b) is the first detailed view of the C5 part in FIG. 5(b), (c) is the second detailed view, and (d) is a detailed view of the C6 part in FIG. 5(c). [Figure 8] (a) is a plan view showing the construction image of Example 2, (b) is a side view of the same construction step 1, (c) is a side view of the same construction step 2, (d) is a side view of the same construction step 3, and (e) is a plan view of the same construction step 4. [Figure 9] (a) is a plan view showing the construction image of the comparative example, (b) is a side view of the same construction step 1', (c) is a side view of the same construction step 2', (d) is a side view of the same construction step 3', and (e) is a plan view of the same construction step 4'. [Figure 10] (a) is the assembled completion drawing of Example 2, and (b) is the assembled completion drawing of the comparative example.
Mode for Carrying Out the Invention
[0021] Hereinafter, the joint structure (joint method) of the concrete member according to the embodiment of the present invention will be described based on Examples 1 and 2.
Example
[0022] Example 1 will be explained based on Figures 4 to 7. In this example, the explanation will be based on the box culvert 1 shown in Figure 1, which is manufactured using precast concrete technology as an example of a concrete product.
[0023] In other words, as described above, the divided blocks T1-T5, B1-B5, and W1-W3 are manufactured in advance at the factory, and then the divided blocks T1-T5, B1-B5, and W1-W3 are joined together at the construction site to construct the box culvert 1 as a precast product. However, in this embodiment, (A) Joints 10, 11 between divided blocks T1 and W1 (B) Joints 10, 11 between divided blocks T5 and W3 Its structure differs from the conventional one (Figure 2).
[0024] On the other hand, the joints of the other divided blocks, that is (C) Joint between divided blocks T1 and T2 (D) Joint between divided blocks T4 and T5 (E) Joint between divided blocks T2 to T4 (F) Joint between divided blocks B1 to B5 (G) Joint between divided blocks T3 and W2 (H) Joint between divided blocks B1 and W1 (I) Joint between divided blocks B3 and W2 (J) Joint between divided blocks B5 and W3 The structure may be configured and joined in the same way as in Figure 4 of this embodiment, or it may be configured and joined in the same way as in the conventional method (Figure 2).
[0025] ≪Structure of the joint≫ Figure 4(a) shows the joints 10 and 11 between divided blocks T1 and W1, and Figure 4(b) shows the joints 10 and 11 between divided blocks T5 and W3. Specifically, divided blocks T1 and T5 are formed in an L-shape in vertical cross-section, with the joint at one end connected to the joint at the other end of divided blocks T2 and T4 (the aforementioned joint structure (C)(D)), and a joint 10 is formed at the other end that is connected to the joint 11 of divided blocks W1 and W3. These joints 10 and 11 constitute the aforementioned joint structure (A).
[0026] On the other hand, the divided blocks W1 and W3 are formed in a plate shape, and the joint portion at their lower end is joined to the joint portion at the upper end of the divided blocks B1 and B5 (the joint structure (H)(J)), and a joint portion 10 is formed at the joint portion 11 at the upper end, which is joined to the divided blocks T1 and T5. These joint portions 10 and 11 constitute the joint structure (B).
[0027] Here, the joints 10 of the divided blocks T1 and T5 are configured symmetrically, and similarly, the joints 11 of the divided blocks W1 and W3 are configured symmetrically. Specifically, the joint 10 is formed in an inverted convex shape in vertical cross-section and includes a pair of left and right notches 12 formed on the inner and outer (C side and D side) surfaces of the box culvert 1, and a protrusion 20 between the notches 12.
[0028] Furthermore, the joint portion 11 is formed in a convex shape in vertical cross-section and includes a pair of left and right notches 13 formed on each side surface (C side and D side) of the inner and outer surfaces (C side and D side) of the box culvert 1, and a protrusion 21 between the notches 13.
[0029] The notches 12 and 13 are configured as cubic notched spaces, with the outer notches 12 and 13 (arrow C side) being cut deeper in the longitudinal direction than the inner notches 12 and 13 (arrow D side), resulting in the joints 10 and 11 having an asymmetrical shape. Note that the depth of the notches 12 and 13 is not limited to that shown in Figure 4, and the joints 10 and 11 may be formed symmetrically.
[0030] In Figure 4, 3a and 3b indicate reinforcing bars 3 extending from the bottom surfaces 12a and 13a of the notches 12 and 13 to the vicinity of the planes (joint surfaces / opposing surfaces) 20a and 21a of the protruding portions 20 and 21. Here, reinforcing bars 3a and 3b are connected using a mechanical joint, i.e., a tubularly formed sleeve 30, which is previously inserted and fitted into the reinforcing bars 3b so as to be movable. Specifically, the sleeve 30 is moved between the reinforcing bars 3a and 3b, and both reinforcing bars 3a and 3b are inserted into the sleeve 30 and fitted. After fitting, the sleeve 30 is filled with a filler material (grout material) to connect the reinforcing bars 3a and 3b. For height and positioning purposes, embedded plates 4a and 4b or similar members are installed at the connection points 10 and 11.
[0031] After the grout material hardens, the joints 10 and 11 are joined by filling the notches 12 and 13 with a filler material G such as non-shrink mortar / grout material. In Figure 4, the notch 13 of joint 11 is formed deeper than the notch 12 of joint 10, so the sleeve 30 is attached to the reinforcing bar 3b in advance. However, if the notch 12 is formed deeper, it is preferable to attach the sleeve 30 to the reinforcing bar 3a in advance. In addition, reinforcing materials such as reinforcing bars may be attached around the sleeve 30 in the notches 12 and 13.
[0032] ≪Detailed Joining Procedure≫ The joining procedure of this embodiment will be explained based on Figures 5 to 7. Here, Figure 6 shows the joining procedure for divided blocks T1 and W1 in Figure 5, and Figure 7 shows the joining procedure for divided blocks T5 and W3 in Figure 5. Here, it is assumed that the joint between divided blocks T2 and T4 and divided block T3 is configured in the same way as in Figure 2 and joined in advance, resulting in the state shown in Figure 5(a).
[0033] (1) Procedure for joining divided blocks T1 and W1 The joining procedure (S01-S03) for the divided blocks T1 and W1 will be explained based on Figures 5 and 6. Here, 10 and 11 in Figure 6 indicate the joining points of the divided blocks T1 and W1 in sections C1-C3 in Figure 5.
[0034] S01: First, as shown by arrow X1 in Figure 6(a), heavy machinery such as a crane is used to move the joint 10 of the divided block T1 onto the joint 11 of the divided block W1 from the side, resulting in the state shown in Figure 6(b).
[0035] At this time, the sleeve 30 is moved to the reinforcing bar 3b on the divided block W1 side in advance. In the state shown in Figure 6(b), the notches 12 and 13 form the recess 31.
[0036] In Figure 5, the joint between divided blocks T1 and T2 (the connection structure (C)) is configured in the same way as in Figure 2, and the joint can be formed by moving divided block T1 in the direction of arrow X1 and inserting the reinforcing bar 3 of the joint of block T2 into the sleeve 2 of the joint of block T1.
[0037] S02: Next, position the reinforcing bars 3a and 2b of the divided blocks T1 and W1 opposite each other while maintaining the state shown in Figure 6(b). After this positioning, move the sleeve 30 in the direction of the reinforcing bar 3a of the divided block T1, as shown by arrow Y1 in Figure 6(c). This inserts the reinforcing bars 3a and 3b into the sleeve 30, attaching the sleeve 30 between the reinforcing bars 3a and 3b, resulting in the completed setup state shown in Figure 6(c).
[0038] S03: With the set completed as shown in Figure 6(c), grout material is filled into the sleeve 30. After the grout material hardens, a filler material G such as non-shrink mortar / grout material is filled into the recess 31, thereby integrating and joining the joints 10 and 11 of the divided blocks T3 and W1.
[0039] (2) Procedure for joining divided blocks T5 and W3 The joining procedure (S11-S13) for the divided blocks T5 and W3 will be explained based on Figures 5 and 7. Here, 10 and 11 in Figure 7 indicate the joining points of the divided blocks T5 and W3 in sections C4-C6 in Figure 5.
[0040] S11: First, as shown by arrow X2 in Figure 7(a), heavy machinery such as a crane is used to move the joint 10 of the divided block T3 onto the joint 11 of the divided block W3 from the side, resulting in the state shown in Figure 7(b). At this time, the sleeve 30 should be moved to the reinforcing bar 3b on the divided block W3 side in advance. In this state of Figure 7(b), the notches 12 and 13 form a recess 31.
[0041] In Figure 5, the joint between divided blocks T4 and T5 (the connection structure (D)) is configured in the same way as in Figure 2, and the joint can be made by moving divided block T5 in the direction of arrow X2, thereby inserting the reinforcing bar 3 of the joint of block T4 into the sleeve 2 of the joint of block T5.
[0042] S12: Next, while maintaining the state shown in Figure 7(b), the reinforcing bars 3a and 2b of the divided blocks T5 and W3 are positioned opposite each other. After this positioning, the sleeve 30 is moved in the direction of the reinforcing bar 3a of the divided block T5, as shown by arrow Y2 in Figure 7(c). This inserts the reinforcing bars 3a and 3b into the sleeve 30, and the sleeve 30 is fitted between the reinforcing bars 3a and 3b, resulting in the completed set state shown in Figure 7(c).
[0043] S13: With the set completed as shown in Figure 7(c), grout material is filled into the sleeve 30. After the grout material hardens, the reinforcing bars 3a and 3b are connected, and then a filler material G such as non-shrink mortar / grout material is filled into the recess 31, thereby integrating and joining the joints 10 and 11 of the divided blocks T5 and W3.
[0044] According to this joining procedure (S01~S03, S11~S13), since the reinforcing bars 3a and 3b only extend to the planes 20a and 21a of the protruding portions 20 and 21, when moving the divided blocks T1 and T5 in the lateral direction (arrows X1 and X2 directions), the reinforcing bars 3b of the joint portion 11 of the divided blocks W1 and W3 do not obstruct the movement, and the state shown in Figures 6(b) and 7(b) can be achieved simply by moving the blocks T1 and T3 in the same direction.
[0045] After that, the sleeve 30 can be moved and filled with grout or non-shrink mortar, allowing the joints 10 and 11 to be easily and integrally joined. This makes it easy to join the segmented blocks T1 and T5 with the segmented blocks W1 and W2, enabling the all-precast box culvert 1 to be easily constructed on-site. In this respect, work efficiency can be improved, construction delays can be prevented, and costs can be reduced.
[0046] As mentioned above, in Figure 5, the joints between divided blocks T1 and T2 and between divided blocks T4 and T5 (the aforementioned joint structures (C) and (D)) are configured in the same way as in Figure 2, but they may also be configured and joined in the same way as joints 10 and 11. [Examples]
[0047] Example 2 will be explained based on Figure 8. This example shows the construction of a manhole block (box-shaped manhole) 100 in a location with limited construction space, where the manhole block 100 is constructed by joining divided blocks 101 and 102.
[0048] On the other hand, Figure 9 shows an example of a comparative example. This comparative example uses a joint structure (joining method) similar to that in Figure 2, and constructs the manhole block 200 by joining the divided blocks 201 and 202.
[0049] (1) In the comparative example, as shown in Figure 9(a), a sleeve 2 is embedded in the joint of the divided block 201, while a reinforcing bar 3 extends from the joint of the divided block 202. As a result, the construction space requires not only the lengths D1 and D2 of the divided blocks 201 and 202 to be installed, but also the gap S between the joints of the two 201 and 202.
[0050] During construction, as shown by arrow E in Figure 9(b), the segmented block 201 is lowered along the segmented block 202 using heavy machinery such as a crane, and each reinforcing bar 3 is positioned opposite each sleeve 2. In this state, the segmented block 201 is moved in the direction of arrow F in Figure 9(c) and each reinforcing bar 3 is inserted into each sleeve 2 and installed. Then, as shown in Figure 9(d), mortar is filled into each sleeve 2, and the manhole block 200 shown in Figure 9(e) is constructed. By stacking these blocks 200, the manhole 200a shown in Figure 10(b) is completed.
[0051] (2) In contrast, in this embodiment, notches 12 and 13 are formed at the joints of the divided blocks 101 and 102, and reinforcing bars 3a and 3b extend from the bottom surfaces of the notches 12 and 13 to the planes 20a and 20b of the protruding parts 20 and 21, and a sleeve 30 is movably attached to the reinforcing bar 3b of the divided block 102.
[0052] In this case, since the reinforcing bars 3a and 3b only extend to the planes 20a and 21a of the protruding portions 20 and 21, as shown in Figure 8(a), only the lengths D1 and D2 of the divided blocks 101 and 102 installed in the construction space are required, and the gap S as in the comparative example is unnecessary.
[0053] During construction, as shown by arrow E in Figure 8(b), the divided block 101 is lowered along the divided block 102 using heavy machinery such as a crane. In this case, since a gap S is not required, it is only necessary to adjust the position so that the reinforcing bar 3a faces the reinforcing bar 3b to which the sleeve 30 is attached, and there is no need to move the divided block 102 in the direction of arrow F.
[0054] Subsequently, as shown in Figure 8(d), the sleeve 30 attached to the reinforcing bar 3b is moved in the direction of the reinforcing bar 3a, i.e., in the direction of arrow L, and the reinforcing bars 3a and 2b are inserted into the sleeve 30. With the sleeve 30 in this state, grout material is filled into it, and after it hardens, a filler material G such as non-shrink mortar / grout material is filled into the recesses 31 of the notches 12 and 13 to construct the manhole block 100 shown in Figure 8(e). By stacking these blocks 100, the manhole 100a shown in Figure 10(a) is completed.
[0055] Thus, according to this embodiment, the only construction space required is the lengths D1 and D2 of the divided blocks 201 and 202, and the gap S as in the comparative example is unnecessary. As a result, not only is joining easy and construction simple, as mentioned above, but the effect of being able to construct concrete products even in narrow construction spaces is also obtained.
[0056] It should be noted that the present invention is not limited to the embodiments described above, and can be modified and implemented within the scope of each claim. For example, the present invention can be applied not only to the box culvert 1 and the manhole block 100, but also to concrete products in general that are constructed by joining divided blocks. [Explanation of Symbols]
[0057] 1…Box culvert 3(3a,3b)...Reinforcing bar 4(4a,4b)...Embedded plate 10,11...Joint part 12, 13… Notches 20,21...Protrusion 30... Sleeves 100…Manhole blocks 100 T1~T5, B1~B5, W1~W3... Divided blocks
Claims
1. A concrete member joining structure for joining divided blocks that constitute a box culvert, The aforementioned box culvert is The first divided block that constitutes the side wall, The second and third division blocks that make up the top plate, Equipped with, The aforementioned second divided block is It is formed in a roughly L-shape in cross-section, One end of it is joined horizontally to the third divided block, The other end is joined perpendicularly to the first divided block. The first joint between the aforementioned end and the third divided block has a first joint embedded in one end and a first reinforcing bar attached to the first joint extending from the other end. The other end and the second joint portion of the first divided block are, A notch formed on the side, A second reinforcing bar extending from the bottom surface of the notch to the opposing surfaces of the second joints, A second joint is movably attached to one of the aforementioned second reinforcing bars, Equipped with, The first reinforcing bar is attached to the first joint by moving the second divided block from the side of the first divided block, The two aforementioned joints are, The two reinforcing bars face each other, A concrete member joining structure characterized by moving the second joint between the two second reinforcing bars while keeping them facing each other.
2. Filler material is filled into the second joint, and after the filler material hardens, the second reinforcing bars are connected. The second joint is, A pair of notches formed on both the inner and outer surfaces, The protruding portion between the notches, Equipped with, The second reinforcing bar extends to the vicinity of the opposite surface of the protruding portion, The notched portion is filled with filler material after the connection between the second reinforcing bars. The concrete member joining structure according to claim 1.
3. By moving the second divided block from the side of the first divided block, the second joint of the second divided block is placed on the second joint of the first divided block, and the reinforcing bars of each block face each other. The concrete member joining structure according to claim 1 or 2.