Reinforcement structure of concrete slab

Abstract

To provide a reinforcement arrangement structure for a concrete slab capable of easily assembling and fixing a reinforcement frame and minimizing the overlap area of a lap joint part.SOLUTION: A slab reinforcement structure according to the present invention is a reinforcement arrangement structure in which a lap joint is constituted by imparting a predetermined lap length between the ends of a plurality of reinforcement frames formed by intersecting and fixing reinforcement consisting of a number of horizontal and vertical reinforcements in a square shape, and the reinforcement arrangement pitch of the first reinforcement and the second reinforcement which adjoin each other at the joint end of each reinforcement frame is set to be equal to or less than the reinforcement arrangement pitch of the second reinforcement and the adjoining third reinforcement. The reinforcement arrangement pitch between the first and second reinforcements is set to about 1 / 2 of the reinforcement arrangement pitch between the second reinforcement and the third reinforcement.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a reinforcement structure for a concrete slab. [Background technology]

[0002] Conventionally, methods for lap jointing and fixing welded wire mesh (wire mesh) including CD mesh are known from Patent Documents 1 to 3.

[0003] Of these, Patent Document 1 discloses a method in which the reinforcing bars protruding from the joint end of the welded wire mesh are tilted upward and used as bar supports on the upper surface, while Patent Document 2 discloses a method in which a separate joining fixing unit is inserted between adjacent joined wire meshes to join them.

[0004] In addition, Patent Document 3 shows a lap joint constructed by crossing vertical and horizontal reinforcement frames with different directions, and does not show a lap joint constructed by arranging multiple welded wire meshes of the same structure in the same direction.

[0005] In contrast to these, the current standard lap joint for welded wire mesh is formed by overlapping the joint ends of identically structured reinforcing bars (welded wire mesh) 32, which are made up of vertical and horizontal reinforcing bars 31b, 31a, one above the other, as shown in Figure 2(A), to form a lap joint 33, as shown in Figure 2(B).To ensure strength, this lap joint 33 requires that the overlap length L between the reinforcing bars 32a (horizontal bars in this case) at the upper and lower joint ends, as shown in Figure 2(C), is the pitch of the horizontal bars + 50 mm and is 150 mm or more. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 60-40475 [Patent Document 2] Japanese Patent Application Publication No. 8-254017 [Patent Document 3] Japanese Patent Application Laid-Open No. 2017-78253 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the method of Patent Document 1 does not ensure the overlap length of the lap joint described above, and the method of Patent Document 2 requires a fixing unit, which is a separate part, at the lap joint, which is costly and has the disadvantage of requiring more fixing points and extra effort to assemble and fix the fixing unit.

[0008] Furthermore, in the conventional standard lap joint shown in Figure 2, if the standard reinforcing bar pitch (standard reinforcing bar pitch) of each reinforcing bar frame exceeds 100 mm, an overlap length greater than the required length is required to ensure the required overlap length described above, and there are drawbacks such as a reduced number of horizontal bars in the lap joint area where higher strength is required.

[0009] Furthermore, in the reinforcement structure shown in Figure 2(C), the horizontal reinforcement positions of the upper and lower reinforcement frames at the lap joint are misaligned, which has the disadvantage that it requires a great deal of effort and skilled techniques to fix the upper and lower reinforcement frames together. [Means for solving the problem]

[0010] The reinforcing bar structure of the present invention for solving the above-mentioned problems is a reinforcing bar structure in which a predetermined overlap length (L) is given to the ends of a plurality of reinforcing bars 2A, 2B, each of which is formed by fastening reinforcing bars consisting of a large number of horizontal reinforcing bars 1a and vertical reinforcing bars 1b arranged in a concrete slab at a standard reinforcing bar arrangement pitch P1 conforming to the standards, crossing each other in a grid pattern, and forming a lap joint 3, and the first reinforcing bars 1a, which are the horizontal reinforcing bars arranged first at the ends of each of the reinforcing bars 2A, 2B, The reinforcing bar pitch P2 between the first reinforcing bar 1a' and the second reinforcing bar 1a, which is a horizontal bar adjacent to the first reinforcing bar 1a', is set to be equal to or less than the standard reinforcing bar pitch P1 between the second reinforcing bar 1a and the third reinforcing bar 1a, which is a horizontal bar adjacent to the second reinforcing bar 1a, and the reinforcing bar frames 2A and 2B are overlapped in an arrangement in which the faces on which the horizontal bars 1a, 1a' of each of the reinforcing bar frames 2A and 2B are arranged face to face with each other and overlap one another vertically. Third rebarThe first reinforcing bar 1a' of the other reinforcing bar frame is arranged on the outside within the lap joint 3 relative to the first reinforcing bar 1a, and is arranged in a position where they overlap close to each other in the left-right direction.

[0011] Secondly, the reinforcing bar arrangement pitch P2 between the first reinforcing bars 1a' and the second reinforcing bars 1a is set to about half the reinforcing bar arrangement pitch P1 between the second reinforcing bars 1a and the third reinforcing bars 1a. [Effects of the Invention]

[0012] According to the reinforcement structure of the present invention configured as described above, by ensuring that the overlap length of the lap joints of the reinforcing bars is kept to the minimum necessary, there is no need to make the overlap width between the reinforcing bars wider than necessary, and the number of reinforcements in the lap joint portion can be more sufficiently ensured. This also has the advantage that the overlapping reinforcing bars can be easily and reliably fixed together. [Brief explanation of the drawings]

[0013] [Figure 1] 1A and 1B are a plan view and an enlarged side view, respectively, showing an example of a reinforcement structure of the present invention, and FIG. 1C is an enlarged side view of the same structure, showing another embodiment. [Figure 2] (A) to (C) are a plan view of a conventional standard reinforcement frame, a plan view of the lap joint portion of the same, and a side view of the same lap joint portion, respectively. DETAILED DESCRIPTION OF THE INVENTION

[0014] Figures 1(A) and (B) show plan views of identical rectangular welded wire mesh (reinforcement frames) 2A and 2B on the left and right, which are made by weaving longitudinal vertical reinforcement 1b and horizontal reinforcement 1a perpendicular to them to form a grid-like mesh, and a side view of slab reinforcing bars in which both reinforcing frames 2A and 2B are joined and fixed with lap joints 3. To make it easier to distinguish the lap joints of the left and right reinforcing frames 2A and 2B in Figure 1(A), the right reinforcing frame 2B is shown with imaginary lines, and both the left and right reinforcing frames are shown to be the same specifications and sizes as those shown in Figure 2.

[0015] The vertical reinforcement 1b and horizontal reinforcement 1a of each reinforcing bar 2A, 2B are basically arranged at a standard reinforcing bar pitch P1 (standard reinforcing bar pitch: assumed to be 100 mm in this example) that conforms to the standards. However, at the ends of both reinforcing bar 2A, 2B that are overlapped at the lap joint 3, the distance (pitch) P2 between the first horizontal reinforcement (first reinforcing bar) 1a' at the overlapping end (joint end) and the adjacent horizontal reinforcement (second reinforcing bar) 1a on the inside is set smaller than the standard reinforcing bar pitch P1 (in this example, it is set to approximately 1 / 2 or less).

[0016] Furthermore, if a single standard pitch P1 is not set for the reinforcing bars 2A, 2B, the spacing P2 between the first reinforcing bar 1a' and the second reinforcing bar 1a is set to approximately half the spacing P1 between the second reinforcing bar 1a and the third reinforcing bar (third reinforcing bar) 1a from the adjacent joint end.

[0017] The left and right reinforcing bars 2A, 2B arranged as described above are stacked one on top of the other to provide or ensure a predetermined overlap length L, as shown in Figures 1(A) and (B), and the adjacent first reinforcing bars 1a' and third reinforcing bars 1a are fixed to each other to form a lap joint 3.

[0018] In the example shown in the same figure (B), the horizontal bar mounting surfaces of both reinforcing bars 2A and 2B are stacked upside down so that they overlap each other vertically, and the first reinforcing bar 1a' and the third reinforcing bar 1a, which are adjacent to each other in the left-right direction, are joined so that they overlap closely together.

[0019] In contrast, in the example shown in the same figure (C), the left and right reinforcing bars 2A, 2B are stacked in the same vertical direction, one horizontal bar 1a, 1a' is pressed against the other vertical bar 1b, and the first reinforcing bars 1a', second reinforcing bars and third reinforcing bars 1a are arranged close together and fixed so that they overlap vertically at the same position on the left and right.

[0020] By placing the horizontal reinforcements 1a', 1a close to each other left and right or top and bottom in this way, the fixing work when fixing the left and right reinforcement frames 2A, 2B together is made easier and the fixing can be done securely and firmly.

[0021] In addition, the above mechanism ensures that a greater number of horizontal reinforcement bars are arranged within the distance (overlap length) L between the first rebars in the lap joint 3, and does not require additional overlapping area for the reinforcing bars 2A and 2B compared to the standard, which has the advantage of saving on the reinforcing bars.

[0022] In the example shown, the reinforcement is arranged assuming a standard reinforcement pitch of 100 mm, but depending on the standard reinforcement pitch, the optimal pitch can be selected for the spacing between the first reinforcing bar 1a' and the second reinforcing bar 1a depending on the purpose.

[0023] In this example, taking into consideration the balance of reinforcement within the lap joint 3, it is desirable that the reinforcement pitch P2 at the joint end be approximately 1 / 2 of the standard reinforcement pitch P1, but it does not necessarily have to be strictly 1 / 2; for example, it is possible to select a pitch slightly higher or lower than 1 / 2, or 1 / 3, 1 / 4, etc. [Explanation of symbols]

[0024] 1a Horizontal bars (second and third bars) 1a´ Horizontal bar (first rebar) 1b Vertical stripes 2A, 2B Reinforced concrete frame on each side 3 Lap joint L overlap length P1 standard reinforcing bar pitch P2 Reinforcement pitch between the first and second reinforcing bars

Claims

[Request 1] The reinforcement is arranged in the concrete slab at a standard reinforcement pitch (P １ The reinforcement structure is a structure in which a predetermined overlap length (L) is given to the ends of a plurality of reinforcing bars (2A, 2B) each of which is formed by fastening reinforcing bars consisting of a large number of horizontal reinforcing bars (1a) and vertical reinforcing bars (1b) arranged in a grid pattern, and a lap joint (3) is formed by providing a predetermined overlap length (L) between the ends of the reinforcing bars (2A, 2B) and the second reinforcing bar (1a) which is a horizontal reinforcing bar adjacent to the first reinforcing bar (1a'). ２ ) is set at the standard reinforcing bar pitch (P １ ) or less, and the reinforcing bars (2A) and (2B) are overlapped in such an arrangement that the surfaces on which the horizontal reinforcing bars (1a) and (1a') of each reinforcing bar (2A) and (2B) are arranged face to face with each other and overlap vertically, and the first reinforcing bar (1a') of one of the reinforcing bars (2A) and (2B) of the overlapping pair of reinforcing bars (2A) and (2B) is arranged outside the third reinforcing bar (1a) of the other reinforcing bar within the lap joint (3) and is arranged in a position where they overlap close to each other in the left-right direction. Request 2 The reinforcing bar pitch (P ２ ) is the reinforcing bar pitch (P １ 2. The reinforcement structure of claim 1, wherein the reinforcement ratio is set to about half of the reinforcement ratio of the concrete slab.

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