Method for preventing displacement at joint in concrete member and joint structure in concrete member

Abstract

To efficiently improve displacement resistance and displacement rigidity at joints in concrete members.SOLUTION: In a method for preventing displacement at joints between a pair of concrete members, including a first concrete member and a second concrete member to be poured on the top of the first concrete member, top sides of one or more wire mesh members having a V-shaped cross section are embedded in the first concrete member, and an opening side of the wire mesh member having the V-shaped cross section is embedded in the second concrete member, and when embedding two or more wire mesh members, intervals between opening sides of the adjacent wire mesh members are spaced wider than the maximum diameter of aggregate in the concrete member.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a method for preventing displacement of joints of concrete members by a net-like member and a joint structure of concrete members.

Background Art

[0002] In a concrete composite structure having reinforcing bars such as a reinforced concrete structure, it is known to join two or more concrete members to form a floor member or a wall member. At this time, at the joint (boundary portion) of two opposing concrete members, it is required to arrange shear reinforcement bars or a steel plate instead of the shear reinforcement bars in order to prevent shear failure in terms of design.

[0003] Inside a concrete composite structure, a technique for reinforcement by providing reinforcing bars has been conventionally devised, and various forms can be considered for the reinforcing bars. For example, Patent Document 1 discloses a composite floor slab configured by combining a reinforcing bar and a lattice bar to form a truss member and enclosing this truss member in concrete in parallel at a plurality of intervals. Patent Document 1 also discloses that it is possible to use expanded metal as this truss member.

[0004] Further, for example, Patent Document 2 discloses a truss-like member for reinforcing a time-dependent curable material such as concrete, and also discloses a composite floor slab structure using this truss-like member.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the joints of concrete members in a concrete composite structure, for example, dowel bars are inserted and mostly used as main reinforcement bars or shear reinforcement bars. In the shear force transmission formula of the concrete standard specification, it is clearly stated that only the fixed bars are effective. When driving an anchor with a short embedment length into the joint, toughness is ensured by plastic hinge formation in the vicinity of the joint due to the dowel action, and substantially, bars with a clear fixing mechanism such as hooks in the compression zone are assumed.

[0007] The above dowel bars serve both as overall shear reinforcement and a displacement prevention mechanism at the joints of concrete members in a concrete composite structure. In order to ensure displacement bearing capacity in the ultimate state, it is necessary to input an excessive amount of reinforcement, and further efficiency improvement is required. Therefore, so-called reticulated members such as truss materials and truss members as described in Patent Documents 1 and 2 may be used.

[0008] However, both of the technologies in Patent Documents 1 and 2 aim to improve the reinforcement effect and workability when enclosing truss materials and truss members inside concrete members, and do not mention or even suggest the reinforcement effect and stiffening effect at the joints (boundary parts) of two opposing concrete members.

[0009] In view of the above circumstances, an object of the present invention is to provide a method for preventing displacement and a displacement prevention structure of a joint of a concrete member that can efficiently improve displacement bearing capacity and displacement stiffness at the joint of the concrete member.

Means for Solving the Problems

[0010] In order to achieve the above object, according to the present invention, there is provided a method for preventing displacement of a joint between a pair of concrete members including a first concrete member and a second concrete member placed on the first concrete member, wherein the top side of one or more wire mesh members having a V-shaped cross section is embedded in the first concrete member, and the opening side of the wire mesh member having a V-shaped cross section is embedded in the second concrete member. When embedding two or more of the wire mesh members, the distance between the opening sides of adjacent wire mesh members is made wider than the maximum diameter of the aggregate in the concrete member.

[0011] The wire mesh member is composed of two flat wire meshes. When embedding the wire mesh member in the first concrete member, the two flat wire meshes may be embedded so as to form a V shape in a cross-sectional view.

[0012] Both ends of the opening side of the wire mesh member having a V-shaped cross section may be respectively edged with steel bars and connected to each other by a connecting member.

[0013] Shear reinforcement bars may be further embedded across between the first concrete member and the second concrete member.

[0014] According to the present invention from another perspective, there is provided a joint structure of concrete members, in which one or more wire mesh members are embedded such that a plane formed by the wire mesh intersects the joint across a pair of concrete members in contact with each other through the joint. The pair of concrete members includes a first concrete member and a second concrete member placed on the first concrete member. In the first concrete member, the top side of a wire mesh member having a V-shaped cross section is embedded, and in the second concrete member, the opening side of the wire mesh member having a V-shaped cross section is embedded. In a configuration where two or more of the wire mesh members are embedded, the distance between the opening sides of adjacent wire mesh members is wider than the maximum diameter of the aggregate in the concrete member. There is provided a joint structure of concrete members characterized by this.

Advantages of the Invention

[0015] According to the present invention, at the joint of concrete members, the shear strength and shear rigidity can be efficiently improved.

[0016] Note that the above effects are not necessarily limited, and together with the above effects, or instead of the above effects, any of the effects shown in this specification, or other effects that can be grasped from this specification may be achieved.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification and the drawings, components having substantially the same functional configuration may be denoted by the same reference numerals, and redundant description may be omitted. In this specification and the drawings, for the sake of explanation, part of the members may be omitted from the illustration, or the internal configuration of the members may be illustrated and described.

[0019] The method for preventing displacement of the concrete joint according to the present invention is applied to the interface of a pair (two) of opposing concrete members. At that time, a wire mesh member is embedded so that the plane formed by the wire mesh intersects the surface that is the joint surface across the pair of concrete members. Various arrangements for embedding this wire mesh member and configurations such as reinforcing bars provided to reinforce the wire mesh member can be considered. Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

[0020] <Configuration of the Joint Structure> FIGS. 1 to 3 are schematic explanatory views of the method for preventing displacement of the concrete joint according to the present embodiment. FIG. 1 is a schematic plan view of the joint structure, FIG. 2 is a schematic side (Y-Z plane) sectional view of the joint structure, and FIG. 3 is a schematic front (X-Z plane) sectional view of the joint structure. In this specification, the width direction of the joint structure is shown and described as the X direction, the longitudinal direction as the Y direction, and the height direction as the Z direction.

[0021] As shown in FIGS. 1 to 3, the joint structure 1 of the concrete member according to the present embodiment includes a pair of upper and lower concrete members. That is, it is configured by placing a second concrete member 20 above a first concrete member 10 that is located below and has been placed first. The boundary plane (XY plane) between the first concrete member 10 and the second concrete member 20 is configured as a joint 25.

[0022] Further, a wire mesh member 30 is embedded so that a plane formed by the wire mesh intersects the joint 25 across between the first concrete member 10 and the second concrete member 20. The wire mesh member 30 according to the present embodiment is configured to have a V shape in a front cross-sectional view as shown in FIG. 3, and its top side 30a is embedded in the first concrete member 10, and its opening side 30b is embedded in the second concrete member 20. The wire mesh member 30 may be a metal plate member preformed in a mesh shape. For example, it may be a so-called expanded metal in which a metal plate is expanded while making cuts in a staggered pattern by an expand manufacturing machine, and the cuts are formed into a diamond shape or a hexagonal shape. The expanded metal may be manufactured from a metal plate such as an iron steel plate, a stainless steel plate, copper, or titanium, or may be manufactured from an alloy plate thereof.

[0023] The wire mesh member 30 according to the present embodiment may be composed of two flat wire meshes 31 and 32, and may be configured by arranging and embedding these two flat wire meshes 31 and 32 so as to form a V shape in a front cross-sectional view. In the wire mesh member 30 having a V shape shown in FIG. 3, the angle θ formed by the two flat wire meshes 31 and 32 is arbitrarily designed. From the viewpoints of workability and efficiency of concrete placement, the angle θ is preferably greater than 0° and less than or equal to 120°. Note that these flat wire meshes 31 and 32 may be composed of materials other than metal such as carbon fiber, aramid fiber, and glass fiber.

[0024] Also, at the opening side 30b of the wire mesh member 30 according to the present embodiment, at least both ends thereof (i.e., the upper ends in the Z direction of the flat wire meshes 31 and 32) may be bordered by steel bars 41 and 42. The steel bars 41 and 42 may be joined by, for example, welding for reinforcing the cut ends of the wire mesh member 30. Thereby, the rigidity of the cut ends of the wire mesh member 30 is improved, and the concrete fixing property of the wire mesh member 30 is also improved. Further, the side ends of the wire mesh member 30 (i.e., both side ends in the Y direction of the flat wire meshes 31 and 32) may be similarly bordered by steel bars 44 and 45. These steel bars 41, 42 and steel bars 44, 45 may be made of materials other than metal such as carbon fiber, aramid fiber, and glass fiber. In addition, even if the flat wire meshes 31 and 32 are bordered by the steel bars 41 and 42, when the out-of-plane rigidity of the flat wire meshes 31 and 32 is weak, a bordering similar to that of the steel bars 41 and 42 may be performed at the lower ends (the lower ends in the Z direction) of the flat wire meshes 31 and 32.

[0025] Further, in the wire mesh member 30 according to the present embodiment, both ends thereof (i.e., the upper ends in the Z direction of the flat wire meshes 31 and 32) may be connected to each other via a connecting member 50. The arrangement and number of the connecting members 50 are arbitrary, and in the configuration according to the present embodiment, they are provided at both longitudinal ends of the wire mesh member 30. The connecting member 50 is made of, for example, a steel bar, and may be joined so as to connect the steel bars 41 and 42 provided for bordering the wire mesh member 30. By providing the connecting member 50, bending of the wire mesh member 30 is suppressed, and in-plane rigidity is improved. Further, by increasing the number of the connecting members 50 and narrowing the arrangement interval thereof, shear displacement deformation can be suppressed.

[0026] The configuration of providing the steel bars 41 and 42 for bordering the wire mesh member 30 and the configuration of connecting both ends of the wire mesh member 30 to each other by the connecting member 50 prevent stepping through when an operator walks on the upper surface of the joint structure 1. Further, since it is bordered by the steel bars 41 and 42, it is possible to prevent an accident in which an operator touches the sharp tip of the wire mesh and gets injured during work around the flat wire meshes 31 and 32.

[0027] <Method for constructing a joint structure> FIG. 4 is a schematic explanatory view showing a method for constructing the joint structure 1 according to the present embodiment, and is a view showing the progress of construction in the order of (a) to (d). First, as shown in FIG. 4(a), the first concrete member 10 before hardening is cast with concrete, and flat wire meshes 31 and 32 as wire mesh members 30 are arranged therein. At this time, the arrangement is made such that only the lower sides of the flat wire meshes 31 and 32 are embedded in the first concrete member 10. These two flat wire meshes 31 and 32 are arranged and embedded so as to form a V shape in a front cross-sectional view. Further, steel bars 41 and 42 are joined and edged to the upper end portions of the flat wire meshes 31 and 32.

[0028] Next, as shown in FIG. 4(b), a connecting member 50 for connecting the upper end portions of the flat wire meshes 31 and 32 to each other is attached. Then, after the first concrete member 10 has hardened, as shown in FIG. 4(c), a time-dependent hardening material U that becomes the second concrete member 20 is cast on the upper portion thereof. At this time, the wire mesh member 30 forms a V shape in a front cross-sectional view, and its upper side (opening side 30b) is open. Therefore, the casting and filling of the time-dependent hardening material U can be performed easily and surely.

[0029] Next, as shown in FIG. 4(d), the casting of the time-dependent hardening material U is completed and hardened, thereby forming the second concrete member 20. In the second concrete member 20, the upper portions of the flat wire meshes 31 and 32 (including the steel bars 41 and 42 and the connecting member 50) protruding from the upper surface of the first concrete member 10 are embedded. That is, after the formation of the second concrete member 20, all of the flat wire meshes 31 and 32, the steel bars 41 and 42, and the connecting member 50 as the wire mesh member 30 are embedded in the concrete.

[0030] In the joint structure 1 constructed as described above, the lower sides of the flat wire meshes 31 and 32 as the wire mesh member 30 are embedded in the first concrete member 10, the upper sides are embedded in the second concrete member 20, and the plane formed by the mesh surface intersects the joint 25 that is the boundary surface between the first concrete member 10 and the second concrete member 20.

[0031] Here, it has been described that the flat wire meshes 31 and 32 as the wire mesh members 30 are arranged in the first concrete member 10, and the concrete is placed such that only the lower sides of the flat wire meshes 31 and 32 are embedded in the first concrete member 10. However, a precast member in which only the lower sides of the flat wire meshes 31 and 32 are embedded in the first concrete member 10 in advance may be manufactured.

[0032] For example, when arranging the two flat wire meshes 31 and 32, it is also conceivable to form a mountain shape (inverted V shape) in a front cross-sectional view and make the lower side an opening. However, in this case, the placement of the concrete placed from above is hindered, the fluidity of the coarse aggregate contained in the first concrete member 10 and the second concrete member 20 into the wire mesh (the space between the wire meshes) deteriorates, and the shear displacement resistance performance at the joint decreases. In addition, the crack resistance performance of the concrete (the performance of suppressing the progress of cracks by the biting of the coarse aggregate after cracks occur) decreases.

[0033] According to the construction method described with reference to FIG. 4, the two flat wire meshes 31 and 32 are arranged and embedded so as to form a V shape in a front cross-sectional view, and the wire mesh member 30 is constituted. That is, the upper side (opening side 30b) of the wire mesh member 30 is open, the placement and filling of the time-dependent hardening material U are easy and reliable, and the decrease in the shear displacement resistance performance and the decrease in the crack resistance performance as described above are suppressed.

[0034] <The effects of the present embodiment> According to the joint structure 1 of the concrete member and the anti-slip method using the same according to the above-described embodiment, the plane formed by the mesh surface of the wire mesh member 30 is provided so as to intersect the joint 25. By using a metal plate member formed in a mesh shape (mesh shape) as the wire mesh member 30, it is possible to exhibit a uniform and continuous fixing performance with respect to the concrete. In addition, compared with a member such as a dowel bar that involves the processing of a conventional fixing hook, the use of the mesh-shaped wire mesh member 30 improves workability and constructability. Further, by using the mesh-shaped wire mesh member 30, it is possible to efficiently improve the slip resistance and slip rigidity at the joint 25 while maintaining toughness without causing brittle fracture such as a short anchor.

[0035] In addition, in the configuration according to the present embodiment, two flat wire meshes 31 and 32 are arranged and used as the wire mesh member 30 so as to form a V shape in a front cross-sectional view. By adopting such a configuration, the filling failure of the time-dependent hardening material U during construction is suppressed, and the efficiency of concrete placement when forming the second concrete member 20 is improved. Further, by forming a V shape in a cross-sectional view within the concrete member, as shown in FIG. 5, the anchor effect in the peeling direction of the joint 25 (see the arrow in FIG. 5) is improved.

[0036] Further, conventionally, in the method for preventing the displacement of the joint 25, a large amount of reinforcing bars were required because a shear reinforcing bar that crosses the entire cross section was also used. However, by providing the wire mesh member 30 so as to intersect the joint 25, optimization of the amount of steel material is achieved in addition to improvement of the slip resistance and slip rigidity. That is, by using a member obtained by continuously processing a thin wire rod, it is possible to effectively obtain the reinforcing effect and the stiffening effect of the joint 25 with a small amount of steel material.

[0037] As described above, an example of the embodiment of the present invention has been described. However, the present invention is not limited to the illustrated form. It is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope of the idea described in the claims, and it is naturally understood that they also belong to the technical scope of the present invention.

[0038] Also, the effects described in this specification are merely illustrative or exemplary and not limiting. That is, the technology according to the present disclosure may exhibit other effects that are apparent to those skilled in the art from the description in this specification, together with or instead of the above effects.

[0039] <Other Embodiments of the Present Invention> In the above embodiment, the wire mesh member 30 is composed of two flat wire meshes 31 and 32, and the case where these two flat wire meshes 31 and 32 are arranged and embedded so as to form a V shape in a front cross-sectional view has been illustrated and described. However, the configuration of the wire mesh member 30 is not limited to this. For example, the wire mesh member 30 may be formed by bending a single flat wire mesh into a V shape in a front cross-sectional view and then arranging and embedding it.

[0040] Also, in the above embodiment, for the sake of explanation, the case where one wire mesh member 30 is embedded in the joint structure 1 of the concrete member has been illustrated and described. However, a plurality of wire mesh members 30 may be embedded in the joint structure 1. The installation interval between the wire mesh members 30 at that time is arbitrarily designed, but it is considered excessive to make the shear displacement strength of the joint 25 equal to or higher than the base material strength of the concrete member. That is, even if only the joint 25 is reinforced, it will be converted into the destruction of other parts and will not contribute to the reinforcement of the entire member. Therefore, increasing the wire mesh member 30 beyond the concrete base material can be said to be an overdesign. In addition, arranging the wire mesh members 30 too densely may also prevent concrete placement. Therefore, when embedding a plurality of wire mesh members 30 in the joint structure 1, an appropriate arrangement configuration is required. Also, in consideration of the manufacturing limit of the flat wire mesh, it is also possible to prevent discontinuity in the displacement direction of the joint by overlapping at the cut in the wire mesh extension direction or arranging the cuts staggeredly.

[0041] In the case of embedding a plurality of V-shaped wire mesh members 30 in the joint structure 1, as an example, the distance between the upper sides (opening sides 30b) of adjacent wire mesh members 30 may be made wider than the maximum diameter of the aggregate contained in the concrete to be placed. Thereby, in the configuration in which the wire mesh members 30 are arranged, the placement and filling of the time-dependent hardening material U (concrete) can be easily and surely performed.

[0042] Further, as another embodiment of the present invention, a configuration in which the configuration of the wire mesh member 30 is different or another reinforcing bar member is embedded in the concrete member is also conceivable. Therefore, hereinafter, an example of another embodiment of the present invention will be described with reference to the drawings. In the following description, components having the same functional configuration as those in the above embodiment may be denoted by the same reference numerals and the description thereof may be omitted.

[0043] <First Another Embodiment> In the above embodiment, the wire mesh member 30 is composed of two flat wire meshes 31 and 32, but the configuration according to the present invention is not limited thereto. FIG. 6 is a schematic front (X-Z plane) sectional view of a joint structure 1a according to the first another embodiment of the present invention.

[0044] As shown in FIG. 6, the wire mesh member 30 according to this embodiment is composed of one flat wire mesh 60, and this flat wire mesh 60 is embedded between the first concrete member 10 and the second concrete member 20 so that the plane formed by the mesh surface intersects the joint 25. As an example, it may be embedded in the vertical direction so that the joint 25 and the flat wire mesh 60 are orthogonal in a sectional view.

[0045] In this embodiment, at least the end portion of the flat wire mesh 60 as the wire mesh member 30 may be edged by a steel bar 62 on the upper side (upper side in the Z direction). The steel bar 62 may be joined, for example, by welding for reinforcing the cut end of the flat wire mesh 60. Further, similar to the above embodiment, the side end portions (that is, both end portions in the Y direction) of the flat wire mesh 60 may be edged with steel bars (not shown in FIG. 6).

[0046] According to the configuration according to the present embodiment, similar to the above embodiment, the slip resistance and the slip rigidity can be efficiently improved, and further reduction of the amount of steel material can be achieved.

[0047] <Second Other Embodiment> In the above embodiment, the configuration in which the wire mesh member 30 is embedded across between the first concrete member 10 and the second concrete member 20 has been described. However, in addition to the wire mesh member 30, a plurality of shear reinforcing bars may be embedded. FIG. 7 is a schematic front (X-Z plane) cross-sectional view of the joint structure 1b according to the second other embodiment of the present invention.

[0048] As shown in FIG. 7, in the configuration according to the present embodiment, shear reinforcing bars 70 are embedded across between the first concrete member 10 and the second concrete member 20. The shape of the shear reinforcing bars 70 is arbitrary, but for example, it may be designed based on the fixability to concrete and may have a shape in which the upper end is folded back in a hook shape in a cross-sectional view.

[0049] Further, in the joint structure 1b, for example, main reinforcing bars 72 and distribution reinforcing bars 73 for connecting a plurality of shear reinforcing bars 70 to each other may be embedded. As shown in FIG. 7, the main reinforcing bars 72 may be reinforcing bars extending in the longitudinal direction (Y direction) of the joint structure 1b, and the distribution reinforcing bars 73 may be reinforcing bars extending in the width direction (X direction) of the joint structure 1b.

[0050] According to the configuration according to the present embodiment, the slip prevention at the joint 25 is performed by the configuration in which the wire mesh member 30 is embedded, and the shear reinforcement of the entire structure of the joint structure 1b is performed by the configuration in which the shear reinforcing bars 70 are embedded. That is, by functionally separating the slip prevention and the shear reinforcement, it becomes possible to construct the joint structure 1b with a more rational design.

[0051] According to the study by the present inventors, the shear displacement deformation of the joint 25 due to the dowel action of the flat metal meshes 31 and 32 occurs only in a minute bending plastic hinge section generated in the displacement deformation direction, which is a section having a depth of about twice the diameter of the shear reinforcement 70. Therefore, unlike conventional shear reinforcements, it is not necessary to attach a fixing mechanism such as a hook or a gusset plate to ensure the tensile strength of the shear reinforcement 70 so that it can withstand the load even if a shear crack occurs at an arbitrary location. That is, in the configuration according to the present embodiment, the horizontal force required for fixing the dowel action of the flat metal meshes 31 and 32 remains at about 1 / 10 of the tensile yield strength of the flat metal meshes 31 and 32. Therefore, the welding strength between the flat metal meshes 31 and 32 and the steel bars 41 and 42 for edge trimming may be slight enough to withstand the weight of an operator walking on the member during construction and the placing pressure during concrete placement. This indicates that even in a member formed in a net shape by a material other than metal such as carbon fiber, aramid fiber, or glass fiber, similar to the flat metal meshes 31 and 32, the shear displacement strength can be sufficiently maintained without guaranteeing the bonding strength with the edge trimming corresponding to the steel bars 41 and 42 up to the tensile strength of the fiber material.

Example

[0052] <Example 1> As Example 1 of the present invention, a joint structure was constructed with each of the configurations shown in FIGS. 8(a) to (d), and a trial calculation was performed thereon. The trial calculation was performed for the shear displacement stress and the shear displacement amount.

[0053] FIG. 8 is an explanatory view according to an embodiment of the present invention, where (a) shows the joint structure of Comparative Example 1, (b) shows the joint structure of Comparative Example 2, (c) shows the joint structure of Invention Example 1, and (d) shows the joint structure of Invention Example 2. Comparative Examples 1 and 2 are joint structures in which only shear reinforcements are embedded, while Invention Examples 1 and 2 are joint structures in which a wire mesh member is embedded in addition to the shear reinforcements.

[0054] In Comparative Example 1 shown in FIG. 8(a), four shear reinforcements per unit width were embedded in the joint structure as shown in the figure. Further, in Comparative Example 2 shown in FIG. 8(b), six shear reinforcements having a diameter thicker than that of Comparative Example 1 per unit width were embedded in the joint structure as shown in the figure.

[0055] On the other hand, in Invention Example 1 shown in Fig. 8(c), in addition to the shear reinforcement bars having the same configuration as in Comparative Example 1, wire mesh members each composed of a single layer of flat wire mesh were embedded at two locations as shown in the figure. Further, in Invention Example 2 shown in Fig. 8(d), in addition to the shear reinforcement bars having the same configuration as in Comparative Example 1, wire mesh members each composed of two layers of flat wire mesh and having a V-shaped cross section were embedded at two locations as shown in the figure. In any of the configurations shown in Figs. 8(a) to 8(d), the configurations of the main reinforcement bars and the force-transferring reinforcement bars to be embedded were made the same.

[0056] Fig. 9 is a graph showing the relationship between the shear displacement stress and the shear displacement deformation amount for each of Comparative Examples 1 and 2 and Invention Examples 1 and 2. As shown in Fig. 9, when comparing Comparative Example 1 and Comparative Example 2, the shear displacement strength is reinforced by a factor of 2, while the shear displacement deformation amount is 1.3 times.

[0057] On the other hand, in Invention Example 1, relative to Comparative Example 1, displacement occurred at the stage where the shear displacement deformation amount became 2 / 3, and the shear displacement stress at that time was 1.5 times. That is, it can be seen that compared with Comparative Example 1, the shear displacement strength has increased and the shear displacement deformation amount has become smaller, so that in addition to the reinforcing effect on the displacement strength, a stiffening effect on the displacement rigidity can also be obtained.

[0058] Further, in Invention Example 2, relative to Comparative Example 2, displacement occurred at the stage where the shear displacement deformation amount became 1 / 3, and the shear displacement stress at that time was equivalent. That is, it can be seen that compared with Comparative Examples 1 and 2, the shear displacement strength has increased and the shear displacement deformation amount has become smaller, so that in addition to the reinforcing effect on the displacement strength, a stiffening effect on the displacement rigidity can also be obtained.

[0059] In the conventionally proposed structures such as shear reinforcement bars formed by three-dimensionally assembling steel bars, although there are no problems with respect to the filling property of concrete, etc., it is inferred from this example that both the shear displacement strength and the shear displacement rigidity can only obtain a lower reinforcing effect compared with the structure using a flat wire mesh (for example, the joint structure 1).

[0060] <Example 2> As Example 2 of the present invention, in a butt joint structure having a configuration conforming to the butt joint structure 1b shown in FIG. 7, an evaluation was made on the relationship between the total weight of steel materials and the shear displacement strength, and the relationship between the total weight of steel materials and the shear spring rigidity, when only shear reinforcing bars were embedded and when wire mesh members were embedded in addition to the shear reinforcing bars. In the configuration where only shear reinforcing bars were embedded, evaluation was performed for the case of using four reinforcing bars (Comparative Example 1), the case of using four reinforcing bars with a larger diameter than that in Comparative Example 1 (Comparative Example 1'), and the case of using six reinforcing bars with an even larger diameter (Comparative Example 2). In the configuration where wire mesh members were embedded in addition to the shear reinforcing bars, evaluation was performed for the case of using four reinforcing bars with the same thickness as in Comparative Example 1 and two wire mesh members (Example 1 of the present invention) and the case of using the same four reinforcing bars and four wire mesh members (Example 2 of the present invention).

[0061] FIG. 10 is a graph showing the relationship between the total weight of steel materials and the shear displacement strength, and FIG. 11 is a graph showing the relationship between the total weight of steel materials and the shear spring rigidity.

[0062] As shown in FIG. 10, when comparing the configuration in which only shear reinforcing bars are embedded ("only reinforcing bars" in the graph) with the configuration in which wire mesh members are embedded in addition to the shear reinforcing bars ("wire mesh reinforcement" in the graph), there is a significant difference in the total weight of steel materials when achieving the same shear displacement strength. For example, when comparing the case of wire mesh reinforcement (Examples 1 and 2 of the present invention) with the case of only reinforcing bars (Comparative Examples 1 and 2), even though the shear displacement strength is the same, the total weight of steel materials in the case of only reinforcing bars is approximately twice that in the case of wire mesh reinforcement.

[0063] Also, as shown in FIG. 11, when comparing the configuration in which only shear reinforcing bars are embedded ("only reinforcing bars" in the graph) with the configuration in which wire mesh members are embedded in addition to the shear reinforcing bars ("wire mesh reinforcement" in the graph), there is a significant difference in their characteristics. In the case of only reinforcing bars, even when the total weight of steel materials increases, the shear spring rigidity does not increase significantly, whereas in the case of wire mesh reinforcement, it can be seen that the shear spring rigidity increases significantly even when the total weight of steel materials does not increase so much.

[0064] From the results of Example 2, according to the butt joint structure provided so as to intersect the butt joint of the wire mesh member according to the present invention, it can be seen that it is possible to efficiently improve both the shear resistance (shearing displacement strength) and the shear rigidity (shearing spring rigidity) with a small amount of steel material.

[0065] In addition, the following configurations also belong to the technical scope of the present invention. [1] A method for preventing displacement of a butt joint of a pair of concrete members including a first concrete member and a second concrete member cast on the first concrete member, burying the top side of one or more wire mesh members having a V-shaped cross section in the first concrete member, burying the opening side of the wire mesh member having a V-shaped cross section in the second concrete member, When embedding two or more of the wire mesh members, the distance between the opening sides of adjacent wire mesh members is made wider than the maximum diameter of the aggregate in the concrete member. A method for preventing displacement of a butt joint of a concrete member, characterized in that. [2] The wire mesh member is composed of two flat wire meshes, and when the wire mesh member is embedded in the first concrete member, the two flat wire meshes are embedded so as to form a V shape in a cross-sectional view. The method for preventing displacement of a butt joint of a concrete member according to [1]. [3] Both ends on the opening side of the wire mesh member having a V-shaped cross section are respectively edged with steel bars and connected to each other by a connecting member. The method for preventing displacement of a butt joint of a concrete member according to [1] or [2]. [4] Shear reinforcement bars are further embedded across between the first concrete member and the second concrete member. The method for preventing displacement of a butt joint of a concrete member according to any one of [1] to [3]. [5] A butt joint structure of a concrete member, One or more wire mesh members are embedded across between a pair of concrete members in contact via the butt joint so that the plane formed by the mesh surface intersects the butt joint. The pair of concrete members includes a first concrete member and a second concrete member placed on the first concrete member. In the first concrete member, the top side of a wire mesh member having a V-shaped cross section is embedded. In the second concrete member, the opening side of the wire mesh member having a V-shaped cross section is embedded. In a configuration where two or more of the wire mesh members are embedded, the distance between the opening sides of adjacent wire mesh members is wider than the maximum diameter of the aggregate in the concrete member. This is a feature of the joint structure of the concrete member.

Industrial Applicability

[0066] The present invention can be applied to a method for preventing displacement of a joint of a concrete member and a joint structure of a concrete member.

Explanation of Signs

[0067] 1... Joint structure 10... First concrete member 20... Second concrete member 25... Joint 30... Wire mesh member 31, 32... Flat wire mesh 41, 42... Steel bars 50... Connecting member

Claims

1. A method for preventing displacement of a joint between a pair of concrete members, including a first concrete member and a second concrete member placed on the first concrete member, comprising: embedding the top side of one or more wire mesh members having a V-shaped cross section in the first concrete member; embedding the opening side of the wire mesh member having a V-shaped cross section in the second concrete member; When embedding two or more of the wire mesh members, the distance between the opening sides of adjacent wire mesh members is made wider than the maximum diameter of the aggregate in the concrete member, characterized in that the method for preventing displacement of the joint of the concrete member.

2. The wire mesh member is composed of two flat wire meshes. When embedding the wire mesh member in the first concrete member, the two flat wire meshes are embedded so as to form a V shape in a cross-sectional view, characterized in that the method for preventing displacement of the joint of the concrete member according to claim 1.

3. Both ends on the opening side of the wire mesh member having a V-shaped cross section are respectively edged with steel bars and connected to each other by a connecting member, characterized in that the method for preventing displacement of the joint of the concrete member according to claim 1 or 2.

4. Shear reinforcement bars are further embedded across between the first concrete member and the second concrete member, characterized in that the method for preventing displacement of the joint of the concrete member according to claim 1.

5. A joint structure of a concrete member, comprising: One or more wire mesh members are embedded across between a pair of concrete members in contact through the joint so that the plane formed by the mesh surface intersects the joint; The pair of concrete members includes a first concrete member and a second concrete member placed on the first concrete member; The top side of the wire mesh member having a V-shaped cross section is embedded in the first concrete member; The opening side of the wire mesh member having a V-shaped cross section is embedded in the second concrete member; In a configuration where two or more of the wire mesh members are embedded, the distance between the opening sides of adjacent wire mesh members is wider than the maximum diameter of the aggregate in the concrete member, characterized in that the joint structure of the concrete member.

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