Concrete stop jig, concrete member using the same and construction method of concrete member

Abstract

To more easily prevent leakage of uncured concrete at concrete joints.SOLUTION: A concrete stop jig 30 is positioned at a concrete joint and fixed to a reinforcing bar 10 connecting one side and the other side across the joint. It comprises: a first member 31 and a second member 32; and gripping portions 34, 35 provided on the first member 31 and the second member 32, respectively. It further comprises an anchor portion fixed to the reinforcing bar 10 while holding the reinforcing bar 10 between the gripping portions 34, 35 to enhance the adhesion strength to the concrete.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a concrete fastening jig, a concrete member using the same, and a method for constructing the concrete member. [Background technology]

[0002] Generally, concrete structures often have concrete joints, where various treatments are carried out to improve the adhesion between the surfaces of the old and new concrete so that the previously poured concrete and the subsequently poured concrete can be integrated.

[0003] For example, in Patent Documents 1 and 2, lath mesh units or embedded formwork with lath mesh are placed at the construction joints to increase the degree of adhesion between the facing surfaces of the old and new concrete. Also, in Patent Document 3, for example, welded wire mesh reinforcement is placed at the boundary between the old and new concrete, and main reinforcing bars are inserted through the welded wire mesh reinforcement. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7385447 [Patent Document 2] Patent No. 6851686 [Patent Document 3] Publication number 4-46432 Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology of Patent Document 1, when pouring concrete on one side of the joint, an air fence must be used in combination to prevent unhardened concrete from leaking to the other side. This increases the number of required parts and increases the time and effort required to install and remove the air fence.

[0006] The technology of Patent Document 2 prevents large amounts of unhardened concrete from leaking by installing a lath net (a formwork that can be buried) with a certain area. However, when reinforcing bars are placed through the lath net, gaps larger than the mesh pitch of the lath net are formed around the reinforcing bars, which can cause concrete to leak through the gaps. For example, as shown in FIG. 9, lath nets 20 with lattice-shaped meshes 21 are brought close to each other from above and below the reinforcing bars 10, and the reinforcing bars 10 are inserted into slits 22 provided at the opposing edges of the upper and lower lath nets 20. Then, as shown in FIG. 10, gaps 23 are created around the reinforcing bars 10 as the slits 22 widen. These gaps 23 are the cause of concrete leakage.

[0007] In this regard, the technology of Patent Document 3 places a concrete leakage prevention plate around the main reinforcing bars that penetrate the welded wire mesh reinforcement, thereby preventing concrete from leaking through gaps around the main reinforcing bars. However, because this concrete leakage prevention plate is a flat, planar member, it may reduce the degree of adhesion between the concrete on both sides of the construction joint. In addition, attaching this concrete leakage prevention plate to the main reinforcing bars is extremely complicated. This is because the main reinforcing bars are shaft-shaped members with a predetermined length, and the concrete leakage prevention plate must be slid axially from the end of the shaft-shaped member to set it in the predetermined position. For this reason, it is desirable to develop a method for more easily preventing concrete leakage.

[0008] Therefore, the first object of this invention is to increase the degree of adhesion of concrete at concrete joints, and the second object is to more easily prevent leakage of unhardened concrete at concrete joints. [Means for solving the problem]

[0009] In order to solve the first problem, the present invention employs a concrete fixing jig that is placed at a concrete joint, fixed to a reinforcing bar connecting one side of the joint and the other, and equipped with an anchor portion that increases the adhesive strength to the concrete (Configuration 1).

[0010] Furthermore, in order to solve the second problem, the present invention employs a concrete stopping jig that is placed at a concrete joint and fixed to a reinforcing bar connecting one side of the joint to the other, the concrete stopping jig comprising a first member and a second member, and clamping portions provided on the first member and the second member, respectively, and that is fixed to the reinforcing bar while holding the reinforcing bar between the clamping portions (Configuration 2).

[0011] In addition, by employing a configuration in which an anchor portion that increases the adhesive strength to the concrete is provided in Configuration 2, the first problem can also be solved (Configuration 3).

[0012] In configuration 2 or 3, a configuration can be adopted in which a hinge portion is provided that supports the first member and the second member so that they can rotate freely, and the first member and the second member are rotated around the hinge portion to open the clamping portions so that the reinforcing bar can be inserted between the clamping portions, and the reinforcing bar can be held between the clamping portions by closing the clamping portions (configuration 4).

[0013] In any one of configurations 2 to 4, a configuration may be adopted in which a locking means is provided that can fix the clamping portions in a closed state (configuration 5).

[0014] In any one of configurations 1 to 5, a configuration can be adopted in which the reinforcing bars are inserted into a planar mesh member arranged in the joint, the first member and the second member are plate-shaped members, and the face direction of the plate surfaces of the first member and the second member is arranged along the face direction of the mesh member (configuration 6).

[0015] A concrete member can be adopted in which the concrete stopping jig described in any one of configurations 1 to 6 is used, the concrete stopping jig is fixed to the reinforcing bars connecting one side and the other side across the joint, a first concrete portion is poured on one side across the joint, and a second concrete portion is poured on the other side across the joint (configuration 7).

[0016] In addition, a method for constructing a concrete member can be adopted, which includes the steps of using a concrete stopping jig described in any one of configurations 1 to 6 to place a reinforcing bar connecting one side and the other side across a position corresponding to the pour joint, fixing the concrete stopping jig to the reinforcing bar, pouring a first concrete section on one side across the position corresponding to the pour joint, and pouring a second concrete section on the other side across the position corresponding to the pour joint (Configuration 8). [Effects of the Invention]

[0017] According to this invention, the degree of adhesion of concrete at concrete joints can be increased, and leakage of unhardened concrete at concrete joints can be more easily prevented. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view showing a first embodiment of the present invention; [Figure 2] FIG. 10 is an enlarged cross-sectional view showing the main part of the embodiment. [Figure 3] Enlarged view of the main part of Figure 1 [Figure 4] Perspective view of concrete stopper jig (open state) [Figure 5] Perspective view of concrete stopper jig (closed state) [Figure 6] FIG. 10 is a perspective view of a concrete fastening jig showing a second embodiment (closed state); [Figure 7] Front view of Figure 6 [Figure 8] 10 is a perspective view of a concrete fastening jig showing a third embodiment. [Figure 9]FIG. 10 is a front view (closed state) of a concrete fastening jig showing a fourth embodiment; [Figure 10] A perspective view of FIG. 9 (closed state) [Figure 11] Enlarged cross-sectional view of the main part of Figure 9 [Figure 12A] Side view of reinforcing steel made from deformed steel bars [Figure 12B] Cross section B-B of Figure 12A [Figure 13] FIG. 10 is an enlarged perspective view of a main part showing a modification of FIG. 9; [Figure 14] A front view showing the state before placing the lath net (mesh-like member) at the position corresponding to the construction joint. [Figure 15] A front view showing the state after placing a lath net (mesh-like member) at the position corresponding to the construction joint. DETAILED DESCRIPTION OF THE INVENTION

[0019] Embodiments of the present invention will be described with reference to the drawings. Figures 1 to 5 show a first embodiment, Figures 6 and 7 show a second embodiment, Figure 8 shows a third embodiment, and Figures 9 to 13 show a fourth embodiment.

[0020] These embodiments relate to a concrete stopping jig 30 placed at a concrete joint, a concrete member 1 using the concrete stopping jig 30, and a method for constructing a concrete member 1 using the concrete stopping jig 30.

[0021] As shown in Fig. 1, concrete member 1 has reinforcing bars 10, mesh members 20, and concrete retaining jigs 30 inside, and concrete is poured over them. In this embodiment, reinforcing bars 10 are horizontal reinforcing bars 11 and vertical reinforcing bars 12 arranged lengthwise and widthwise, but reinforcing bars 10 may also be arranged in locations and directions other than those shown in the figure as appropriate. Reinforcing bars 10 that are close to each other are fixed together with bundling members such as wire so that they do not move relative to each other even when the concrete is not yet hardened.

[0022] Concrete is poured in multiple stages within a formwork (not shown). Concrete is poured sequentially into the formwork, which contains reinforcing bars 10, mesh members 20, and concrete retaining jigs 30. Here, the opposing surfaces (joint surfaces) between the concrete member that was poured first and the concrete member that was poured afterwards are called the pouring joint. The concrete member that was poured first is called the first concrete section A, and the concrete member that was poured afterwards is called the second concrete section B.

[0023] The mesh member 20 is composed of a mesh member in which the mesh formed by the intersection of metal wires 21 is continuous in a plane. The mesh member 20 is placed at a position corresponding to a construction joint, that is, a position where a construction joint will be formed after the unhardened concrete has hardened.

[0024] (First embodiment) 2 to 5, the concrete fastening jig 30 of the first embodiment includes a first member 31 and a second member 32, which are rotatably supported by a hinge portion 36. The first member 31 and the second member 32 are also provided with clamping portions 34, 35 that hold the reinforcing bar 10, respectively.

[0025] By rotating the first member 31 and the second member 32 around the hinge portion 36 and opening the clamping portions 34, 35 as shown in Fig. 4, the reinforcing bar 10 can be inserted between the clamping portions 34, 35 (open state). Also, by closing the clamping portions 34, 35 as shown in Fig. 5, the reinforcing bar 10 can be held between the clamping portions 34, 35 (closed state).

[0026] In this way, the first member 31 and the second member 32 that constitute the concrete fastening jig 30 are opened. By making it closable, the concrete stopping jig 30 can be quickly fixed at any position in the axial direction of the reinforcing bar 10. In other words, unlike the conventional method, it is no longer necessary to slide the concrete leakage prevention plate (corresponding to the concrete stopping jig 30 of this invention) significantly along the axial direction of the reinforcing bar, which simplifies the work and reduces the work time.

[0027] The concrete fastening jig 30 also includes a locking means 33 that can lock the clamping portions 34, 35 in a closed state (as shown in FIG. 5 ). The locking means 33 of the first embodiment is composed of a U-shaped cross-section member that clamps and secures the edges of the overlapping first and second members 31, 32. As shown in FIGS. 4 and 5 , the U-shaped cross-section locking means 33 includes a base 33a that follows the edges of the first and second members 31, 32, and a pair of rising portions 33b, 33c that rise in the same direction from the base 33a. Of the pair of rising portions 33b, 33c, one rising portion 33c is connected to the second member 32. This connection may be achieved by welding the second member 32 and the locking means 33, or they may be manufactured as a single member. Alternatively, the other rising portion 33b of the pair of rising portions 33b, 33c may be connected to the first member 31.

[0028] The locking means 33 may be hinged to either the first member 31 or the second member 32 so as to be rotatable. Alternatively, the locking means 33 may be a separate member that can be separated from the first member 31 and the second member 32, rather than being connected to either the first member 31 or the second member 32. Furthermore, the locking means 33 may be a member other than the U-shaped cross section of the first embodiment, as long as it can hold the first member 31 and the second member 32 in the closed state (the state shown in FIG. 5 ). For example, the locking means 33 may be a member that passes through holes (such as second holes 31b and 32b and third holes 31c and 32c, which will be described later) that penetrate the first member 31 and the second member 32, and plastically deforms the wire to fasten and bind the first member 31 and the second member 32. Alternatively, the first member 31 and the second member 32 may be fastened by welding; that is, the locking means 33 may be a welded portion that joins the first member 31 and the second member 32.

[0029] In the first embodiment, in order to increase the adhesive strength between the concrete at the joint between the first concrete section A and the second concrete section B, the surface direction of the mesh member 20 is aligned with the surface direction of the joint. Furthermore, the first member 31 and the second member 32 of the concrete stopping jig 30 are plate-like members, and the surface direction of these plate-like members is aligned with the surface direction of the mesh member 20, thereby minimizing concrete leakage.

[0030] As shown in FIGS. 4 and 5, the clamping portions 34, 35 of the first embodiment are formed by recesses provided in the first member 31 and the second member 32, and the recesses have arc portions 34b, 35b at their open ends. The arc portion 34b of the first member 31 and the arc portion 35b of the second member 32 form a continuous arc when the clamping portions 34, 35 are closed (as shown in FIG. 5). This arc portion fits along the circumferential surface of the reinforcing bar 10, minimizing gaps through which concrete leaks. The innermost portions of the clamping portions 34, 35 are formed by straight portions 34a, 35a connecting the innermost ends of the arc portions 34b, 35b. While these straight portions 34a, 35a create gaps between the circumferential surface of the reinforcing bar 10 and the straight portions 34a, 35a, the gaps are smaller than the gaps in the mesh of the mesh member 20 (see FIG. 10), and the amount of concrete leaking through these gaps is minimal. The shapes of the clamping portions 34 and 35 can be changed as appropriate.

[0031] The first member 31 and the second member 32 are provided with first holes 31a and 32a, second holes 31b and 32b, and third holes 31c and 32c, respectively.

[0032] The first holes 31a, 32a are overlapped at the same position. In the first embodiment, a cylindrical portion protruding toward the first member 31 is provided around the first hole 32a of the second member 32, and after the cylindrical portion is inserted into the first hole 31a of the first member 31, the protruding end of the cylindrical portion is crimped to prevent it from coming off. This allows the first member 31 and the second member 32 to rotate freely. Note that a pin 36a constituting the hinge portion 36 may be inserted into the first holes 31a, 32a. In this case, one end of the cylindrical portion of the pin 36a has a head with a slightly larger diameter. After the other end is inserted into the first holes 31a, 32a, the other end is crimped by plastic deformation to prevent it from coming off between the head and the crimped portion.

[0033] The second holes 31b and 32b are also placed in the same position. Unhardened concrete fills the second holes 31b and 32b and the third holes 31c and 32c, thereby enhancing adhesion between the concrete pieces at the joint. In other words, the second holes 31b and 32b and the third holes 31c and 32c form anchors that enhance adhesion strength to the concrete.

[0034] The method and steps for constructing the concrete member 1 will be described below.

[0035] First, reinforcing bars 10 are placed in the formwork. A portion of the reinforcing bars 10 connects the first concrete section A on one side to the second concrete section B on the other side, across a construction joint. The reinforcing bars 10 that straddle the construction joint are particularly referred to below as penetrating reinforcing bars 10. The penetrating reinforcing bars 10 are inserted through the mesh of the reticulated member 20. The process of placing the penetrating reinforcing bars 10 and the reticulated member 20 in the formwork is referred to as the first process. In the first process, the reticulated member 20 is set at a position corresponding to the construction joint.

[0036] Next, the concrete fastening jig 30 is fixed to the reinforcing bar 10. This step is called the second step. The first and second steps can also be performed simultaneously. The concrete fastening jig 30 can be easily fixed to the reinforcing bar 10 by opening and closing the first member 31 and the second member 32, as shown in Figures 4 and 5. Fixing using the locking means 33 is optional and can be omitted.

[0037] Then, unhardened concrete is poured onto one side of the mesh member 20 (sandwiched at a position corresponding to the pouring joint) and allowed to harden, thereby casting the first concrete section A. This step is called the third step. Here, the concrete stopping jig 30 is attached to the reinforcing bar 10, preventing a large amount of unhardened concrete from leaking out from between the reinforcing bar 10 and the mesh member 20. The curing period until the unhardened concrete hardens is set appropriately according to the specifications of the concrete used.

[0038] After the first concrete section A is poured, unhardened concrete is poured on the other side of the mesh member 20 (sandwiching the position corresponding to the joint), and is then hardened to pour the second concrete section B. This step is called the fourth step. The concrete stopping jig 30 is interposed in the joint along with the mesh member 20, thereby enhancing the adhesion between the concrete pieces. The first member 31 and the second member 32 of the concrete stopping jig 30 are plate-like members, and the surface direction of these plate-like members is aligned with the surface direction of the mesh member 20. This further enhances the degree of adhesion between the concrete pieces at the joint.

[0039] (Second embodiment) A second embodiment is shown in Figures 6 and 7. In this second embodiment, protrusions 37, 38 are provided on a concrete fastening jig 30. Specifically, the first member 31 has a protrusion 38 facing toward the first concrete portion A and a protrusion 37 facing toward the second concrete portion B. The second member 32 also has a protrusion 38 facing toward the first concrete portion A and a protrusion 37 facing toward the second concrete portion B. These protrusions 37, 38 are provided on the outer edges of the first member 31 and the second member 32, and are hereinafter referred to as outer protrusions 37, 38. The outer protrusions 37, 38 are embedded in the hardened concrete, further enhancing the degree of adhesion between the concrete pieces at the joint. In other words, these protrusions 37, 38 constitute anchors that enhance the adhesion strength to the concrete. The position and shape of the outer protrusions 37, 38 can be changed as appropriate, and the number, protruding height, and protruding direction of the outer protrusions 37, 38 can also be changed as appropriate.

[0040] For example, the outer protrusions 37, 38 in the second embodiment have root portions 37a, 38a that protrude from the first member 31 and the second member 32 along the axial direction of the reinforcing bar 10, and bent portions 37b, 38b that are provided at the tip side of the root portions 37a, 38a and extend in a direction intersecting the axial direction of the reinforcing bar 10.However, it is also possible to adopt a configuration in which the protruding direction of the root portions 37a, 38a is inclined with respect to the axial direction of the reinforcing bar 10, or a configuration in which the bent portions 37b, 38b are omitted.

[0041] Furthermore, the concrete fastening jig 30 has additional protrusions 39, 40 located inward of the outer protrusions 37, 38. The first member 31 has a protrusion 40 facing toward the first concrete portion A and a protrusion 39 facing toward the second concrete portion B. The second member 32 also has a protrusion 40 facing toward the first concrete portion A and a protrusion 39 facing toward the second concrete portion B. These protrusions 39, 40 are provided on the inner edges (edges of the clamping portions 34, 35) of the first member 31 and the second member 32, respectively, and will be referred to as the inner protrusions 39, 40 hereinafter. The inner protrusions 39, 40 are embedded in the hardened concrete, forming anchors that also enhance adhesion strength to the concrete. The position and shape of the inner protrusions 39, 40 can be modified as needed, as can the number, protrusion height, and protrusion direction of the inner protrusions 39, 40.

[0042] As shown in FIGS. 6 and 7, the inner protrusions 39, 40 also function to position the concrete fastening jig 30 relative to the mesh member 20 by holding the wires 21 of the mesh member 20.

[0043] Furthermore, like the outer protrusions 37, 38, the inner protrusions 39, 40 of the second embodiment have a root portion 39a, 40a that protrudes from the first member 31 and the second member 32 along the axial direction of the reinforcing bar 10, and a bending portion 39b, 40b that is provided at the tip side of the root portion 39a, 40a and extends in a direction intersecting the axial direction of the reinforcing bar 10.However, it is also possible to adopt a configuration in which the protruding direction of the root portion 39a, 40a is inclined with respect to the axial direction of the reinforcing bar 10, or a configuration in which the bending portion 39b, 40b is omitted.

[0044] In each of the above embodiments, the first member 31 and the second member 32 that constitute the concrete fastening jig 30 are rotatable via the hinge portion 36, but an embodiment in which the hinge portion 36 is omitted is also conceivable. In this case, it is preferable to provide a fall-off prevention member that holds the reinforcing bar 10 with the clamping portions 34, 35 by clamping the reinforcing bar 10 between the first member 31 and the second member 32, and prevents the first member 31 and the second member 32 from falling off the reinforcing bar 10 in this state. For example, a member similar to the locking means 33 described above can be used as the fall-off prevention member.

[0045] (Third embodiment) A third embodiment is shown in Fig. 8. In this third embodiment, the first member 31 and the second member 32 are molded as a single member. In other words, the concrete fastening jig 30 is made up of the first member 31, which is a single plate-shaped member, and does not use the second member 32.

[0046] The first member 31 is provided with a clamping portion 34 that clamps the reinforcing bar 10. The clamping portion 34 is configured as a hole that penetrates the first member 31 in the plate thickness direction. The shape of the clamping portion 34 matches the clamping portions 34, 35 in the closed state in the first and second embodiments, but may be other shapes. In addition, the configurations of the outer protrusions 37, 38 and the inner protrusions 39, 40 are the same as in the second embodiment, but may be other shapes.

[0047] In the above-described embodiments, the outer shape of the concrete fastening jig 30 in front view is a square. However, the present invention is not limited to these embodiments, and the outer shape of the concrete fastening jig 30 in a front view can be freely set. For example, the outer shape of the concrete fastening jig 30 in a front view may be rectangular, such as a rectangle, or may be circular, elliptical, or the like.

[0048] (Fourth embodiment) A fourth embodiment is shown in Figures 9 to 13. In this fourth embodiment, the inner diameter surface of a concrete fastening jig 30 is elliptical.

[0049] Deformed steel bars are generally used as reinforcing bars 10 embedded in concrete. As shown in FIG. 12A, deformed steel bars are shaft-shaped components with axially extending longitudinal ribs 10b and circumferentially extending transverse ribs 10a formed on an outer surface 10c that is primarily composed of a curved surface such as a cylindrical surface. In this deformed steel bar, the cross section of the portion without transverse ribs 10a (part BB in FIG. 12A, hereinafter referred to as the "joint portion") has longitudinal ribs 10b, 10b protruding from the outer surface 10c in 180-degree opposite directions across the axis of the reinforcing bar 10, as shown in FIG. 12B. Therefore, the cross section of the joint portion has a generally elliptical shape in which the transverse diameter Y (the length in the direction connecting the longitudinal ribs 10b, 10b) is longer than the longitudinal diameter X (the length in the direction perpendicular to the longitudinal ribs 10b, 10b). A concrete fastening jig 30 is fixed to this generally elliptical joint portion. Note that the symbol Z in Figure 12B is the top-to-top dimension Z, which corresponds to the distance between the top of the upper horizontal rib 10a and the top of the lower horizontal rib 10a in the arrow view of Figure 12B, and the horizontal diameter Y and the top-to-top dimension Z are usually set equal (Y = Z) by design.

[0050] 9 and 10, the concrete fastening jig 30 includes a first member 31 and a second member 32 that are arc-shaped when viewed from the front, and the first member 31 and the second member 32 are rotatably supported by a hinge portion 36. The first member 31 and the second member 32 are provided with clamping portions 34, 35 on the inner diameter sides thereof, respectively, that hold the reinforcing bar 10. The clamping portions 34, 35 of the first member 31 and the second member 32 are arc-shaped (simple curves with a constant curvature in the fourth embodiment), and the outer diameter surfaces of the first member 31 and the second member 32 are also arc-shaped (simple curves with a constant curvature in the fourth embodiment).

[0051] The outer diameter surfaces of the first member 31 and the second member 32 do not necessarily have to be arc-shaped. For example, they may be rectangular or polygonal in front view, or may have a shape with continuous irregularities on the outer edge. In the fourth embodiment, a handle portion 41 that protrudes outward is provided on the outer edge of the second member 32, making it easier to rotate the first member 31 and the second member 32 about the hinge portion 36.

[0052] As in the first and second embodiments, the hinge portion 36 has a cylindrical portion 32d that protrudes toward the first member 31 around the first hole 32a of the second member 32, and after the cylindrical portion 32d is inserted into the first hole 31a of the first member 31, the protruding end of the cylindrical portion 32d is crimped to prevent it from coming off. This allows the first member 31 and the second member 32 to rotate freely. Alternatively, a pin 36a that constitutes the hinge portion 36 may be inserted into the first holes 31a, 32a.

[0053] By rotating the first member 31 and the second member 32 around the hinge portion 36, the clamping portions 34, 35 are opened, and the reinforcing bar 10 can be inserted between the clamping portions 34, 35 (open state). Also, by rotating the first member 31 and the second member 32 around the hinge portion 36 to close the clamping portions 34, 35, the reinforcing bar 10 can be held between the clamping portions 34, 35 (closed state).

[0054] When closed, the clamping portions 34, 35 form a continuous arc, conforming to the circumferential surface of the reinforcing bar 10 to minimize gaps through which concrete can leak. Here, in the state indicated by solid lines a, a' in Figure 9, the inner diameter portions (clamping portions 34, 35) of the first member 31 and the second member 32 are nearly circular. However, when they are further rotated to the state indicated by dashed lines b, b', the inner diameter portions (clamping portions 34, 35) become approximately elliptical, with a horizontal diameter Y' longer than the vertical diameter X'. This allows for a wider area (longer length in the circumferential direction) of the joint portion of the reinforcing bar 10, which is made of deformed steel bars, to be in close contact, thereby minimizing the gap between the concrete fastening jig 30 and the reinforcing bar 10. This prevents concrete or mortar from leaking through the gap between the concrete fastening jig 30 and the reinforcing bar 10 and also more firmly secures the concrete fastening jig 30 and the reinforcing bar 10 to prevent movement.

[0055] As described above, when the first member 31 and the second member 32 are closed, the arc-shaped clamping portions 34, 35 have an overall shape that is not a perfect circle, i.e., a non-circular shape, and the clamping portions 34, 35 have a shape in which the horizontal diameter Y' is longer than the vertical diameter X' so that they fit along the outer surface of the joint portion of the deformed steel bar. As a result, the concrete stopping jig 30 can be tightly attached to the outer surface of the reinforcing bar 10, which has a non-circular cross section, and concrete leakage and movement of the concrete stopping jig 30 can be suppressed.

[0056] In the fourth embodiment, both the clamping portion 34 of the first member 31 and the clamping portion 35 of the second member 32 are formed as portions of arcs of a perfect circle (simple curves with a constant curvature), and rotation of the first member 31 and the second member 32 results in the clamping portions 34, 35 having a shape in which the horizontal diameter Y' is longer than the vertical diameter X' as a whole. However, by forming at least one of the clamping portions 34, 35 of the first member 31 and the second member 32 having the arc-shaped clamping portions 34, 35 into a non-circular curve such as an ellipse, it is possible to achieve a shape in which the horizontal diameter Y' is longer than the vertical diameter X' as described above. For example, one of the clamping portion 34 of the first member 31 and the clamping portion 35 of the second member 32 may be formed as a portion of an arc of a perfect circle (simple curves with a constant curvature), and the other may be formed as a portion of an ellipse whose minor and major axes are set to different lengths.

[0057] Also, similar to the above-described embodiments, the first member 31 and the second member 32 are provided with first holes 31a, 32a, second holes 31b, 32b, and third holes 31c, 32c, respectively (see Figures 9 and 10).

[0058] The first holes 31a, 32a are overlapped in the same position to form the aforementioned hinge portion 36. In the solid line state of FIG. 9 (see symbols a, a') and FIG. 10, the second holes 31b, 32b are also overlapped in the same position, but in the dashed line state of FIG. 9 (see symbols b, b'), the second holes 31b, 32b are slightly offset from each other (the offset hole positions are not shown). As with the above-described embodiments, pouring concrete causes unhardened concrete to fill the first holes 31a, 32a, the second holes 31b, 32b, and the third holes 31c, 32c, respectively, thereby enhancing the degree of adhesion between the concrete pieces at the joint.

[0059] Here, the third holes 31c, 32c have protrusions 31d, 32d along the inner edges of the holes. These protrusions 31d, 32d enhance the adhesion between the concrete fastening jig 30 and the concrete. In the fourth embodiment, the protrusions 31d, 32d are cylindrical and extend continuously around the entire circumference of the holes along the inner edges, but other shapes may be used. For example, the protrusions 31d, 32d may be provided intermittently along the inner edges of the holes. Furthermore, similar to the third holes 31c, 32c, the first holes 31a, 32a and the second holes 31b, 32b may also have protrusions 31d, 32d.

[0060] These protrusions 31d, 32d can also be formed by burring, for example, as shown in FIG. 13 . Burring is a processing method for creating raised portions around holes drilled in a plate material. By creating the protrusions 31d, 32d by burring, even in situations where it is difficult to create tall protrusions in the axial direction of the reinforcing bar 10 due to the dense reinforcement around the location where the concrete fastening jig 30 is to be installed, the low-profile protrusions 31d, 32d formed by burring can enhance the adhesion of concrete. The protrusions 31d, 32d formed by burring may be formed on the concrete fastening jig 30 in advance, or the protrusions 31d, 32d can be added later by performing burring after the concrete fastening jig 30 is fixed to the reinforcing bar 10.

[0061] In the fourth embodiment, the protrusion amount of the protrusions 31d and 32d is set to 2.0 mm. This is because if the protrusion amount is 0.5 mm or less, it is not sufficient to compensate for the adhesive force with the concrete, and if the protrusion amount exceeds 5.0 mm, burring processing becomes difficult.

[0062] The protrusions 31d, 32d can exert their effect as long as they are provided on at least one of the front and back surfaces of the first member 31 and the second member 32. To ensure smooth rotation of the first member 31 and the second member 32 around the hinge portion 36, it is desirable to provide the protrusions 31d, 32d on the surface (outer surface) opposite the opposing surface (inner surface) that faces each other when the first member 31 and the second member 32 are stacked. However, as long as this rotation is not hindered, the protrusions 31d, 32d may be provided on the inner surface of the first member 31 and the second member 32, or on both the inner surface and the outer surface. In this case, providing the protrusions 31d, 32d on each of the first member 31 and the second member 32 so that they alternately protrude from the inner surface and the outer surface along the arc direction of the first member 31 and the second member 32 is advantageous in terms of enhancing adhesion to concrete.

[0063] In addition, in each of the above embodiments, the surface direction of the construction joint is vertical, and the mesh members 20 are arranged so that their surface direction faces vertically, but the surface direction of the construction joint can take various forms. For example, this invention can be applied even when the surface direction of the construction joint is horizontal or inclined relative to the horizontal. Furthermore, this invention can be applied even in an embodiment in which the installation of the mesh members 20 is omitted, or in an embodiment in which members of other shapes are arranged in the construction joint instead of the mesh members 20. [Explanation of symbols]

[0064] 1 Concrete members 10 Reinforced concrete 20 Mesh-like member 21 mesh 30 Concrete Stopper 31 First member 32 Second member 34,35 Clamping part 33 Locking means 36 Hinge part 37,38 protrusion (outer protrusion) 39,40 protrusion (inner protrusion) A First concrete section B Second concrete section

Claims

1. The concrete fixing jig is arranged at a concrete joint, fixed to a reinforcing bar (10) that connects one side of the joint to the other side, and equipped with an anchor part that enhances the adhesive strength to the concrete.

2. A concrete fixing jig (30) is placed at a concrete joint and fixed to a reinforcing bar (10) connecting one side of the joint to the other side, The concrete fastening jig comprises a first member (31) and a second member (32), and clamping portions (34, 35) respectively provided on the first member (31) and the second member (32), and is fixed to the reinforcing bar (10) while holding the reinforcing bar (10) between the clamping portions (34, 35).

3. The concrete fastening jig according to claim 2, further comprising an anchor portion for increasing adhesive strength to the concrete.

4. A concrete fastening jig as described in claim 2, which is provided with a hinge portion (36) that supports the first member (31) and the second member (32) so that they can rotate freely, and by rotating the first member (31) and the second member (32) around the hinge portion (36) to open the clamping portions (34, 35), the reinforcing bar (10) can be inserted between the clamping portions (34, 35), and by closing the clamping portions (34, 35), the reinforcing bar (10) can be held between the clamping portions (34, 35).

5. Using the concrete fastening jig (30) according to any one of claims 1 to 4, The concrete stopping jig (30) is fixed to a reinforcing bar (10) that connects one side and the other side of the joint, and a first concrete section (A) is poured on one side of the joint, and a second concrete section (B) is poured on the other side of the joint.

6. Using the concrete fastening jig (30) according to any one of claims 1 to 4, A method for constructing a concrete member, comprising the steps of: placing a reinforcing bar (10) connecting one side and the other side across a position corresponding to the joint; fixing the concrete stopping jig (30) to the reinforcing bar (10); pouring a first concrete section (A) on one side across the position corresponding to the joint; and pouring a second concrete section (B) on the other side across the position corresponding to the joint.

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