JP2017155482A - Shear reinforcement structure of reinforced-concrete structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve fixation performance of a reinforcement member, to surely increase shear load bearing force of a reinforced-concrete structure, and to improve workability.SOLUTION: A reinforcement member insertion hole 20 bored in a reinforced-concrete structure 10 comprises the innermost side insertion hole 21 positioned on the innermost side of the reinforced-concrete structure 10 and a diameter expanding insertion hole 22 positioned on this side in the insertion direction of a reinforcement member 30 and in a concrete-covering thickness of an existing main reinforcement 41 and having an inner diameter larger than an inner diameter of the innermost side insertion hole 21. The reinforcement member 30 inserted into the reinforcement member insertion hole 20 comprises a body part 31, a first fixation body 32 provided in an end part of the body part 31 and a second fixation body 33 connected by a connection part 35 to the first fixation body 32 on this side in the insertion direction and arranged in the vicinity of the existing reinforcement 41 in the diameter expanding insertion hole 22. A thickness of the connection part 35 is thinner than the body part 31, and a maximum diameter of the second fixation body 33 is two times or more of a maximum diameter of the body part 31.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a shear reinforcement structure for a reinforced concrete structure, for example, a shear reinforcement structure suitable for reinforcement work for an existing reinforced concrete structure.

  In preparation for a large-scale earthquake that is likely to occur in the near future, the importance of seismic reinforcement for reinforced concrete structures has been recognized, and various proposals regarding seismic reinforcement work have been made (for example, Patent Document 1 and Patent Document 2). reference). If the existing reinforced concrete structure has insufficient shear load capacity, it is necessary to increase the shear load capacity of the reinforced concrete structure by adding a reinforcing member in a direction crossing the main reinforcing bar. In such reinforcement work, not only the reinforcement member needs to be firmly fixed, but also damage to existing structures is minimized, and further ease of construction is required.

  The technique described in Patent Document 1 relates to a shear reinforcement structure, and is mainly a reinforcement made of an existing reinforced concrete structure and a wire disposed inside a reinforcement member insertion hole formed in the reinforced concrete structure. It consists of a member and the filler with which a reinforcement member insertion hole is filled. And the reinforcing member is arrange | positioned in the state which ensured the covering concrete thickness equivalent to the existing main reinforcement arranged in the reinforced concrete structure by the base end side and the front end side. Further, the reinforcing member insertion hole includes a general portion having an inner diameter larger than the diameter of the wire, and a base end widening portion formed at the base end portion of the reinforcing member insertion hole and having an inner diameter larger than the general portion. Yes.

  The technique described in Patent Document 2 relates to a shear reinforcement structure of an existing reinforced concrete structure, and is drilled in an existing wall-shaped or plate-shaped reinforced concrete structure from one side of the structure to the opposite side. The reinforcing steel material insertion hole provided, the reinforcing steel material made of bar steel inserted into the reinforcing steel material insertion hole, and the curable filler filled in the gap between the reinforcing steel material insertion hole and the reinforcing steel material are used as constituent elements. A fixing body made of a corrosion-resistant material covering the end portion is integrated with the end portion of the reinforcing steel material, and a fixing portion having a diameter larger than the outer diameter of the reinforcing steel material is formed near the surface of the reinforced concrete structure. ing,

Japanese Patent No. 4157510 Japanese Patent No. 5003448

  However, in the technique described in Patent Document 1, the reinforcing member must be disposed in a state where a covering concrete thickness equivalent to that of the existing main reinforcing bar arranged in the reinforced concrete structure is secured. The position is limited.

  Further, the reinforcing member insertion hole is provided with a base end widened portion having an inner diameter larger than the general portion on the base end side, and this base end widened portion is a portion for inserting a plate head or the like, As mentioned above, the reinforcement member must be placed in a state where the covering concrete thickness equivalent to that of the existing main reinforcement is secured. It will be arranged by.

  For this reason, even if it is a case where sufficient covering concrete thickness can be ensured between a reinforced concrete structure and a main reinforcing bar, since a reinforcement member cannot be arranged in the position concerned, it is flexible according to the situation. Cannot be designed properly.

  In the technique described in Patent Document 2, since the fixing portion having a diameter larger than the outer diameter of the reinforcing steel material is provided, the fixing performance of the reinforcing member can be improved, but this fixing portion is near the surface of the reinforced concrete structure. It is arranged. In consideration of the description of the specification and the drawings of Patent Document 2, the vicinity of the surface of the reinforced concrete structure means a position shallow from the surface, a position equivalent to the surface (level), and a position protruding from the surface. For this reason, when the fixing part is made of metal, rust prevention treatment is indispensable, and the fixing part protrudes from the surface of the reinforced concrete structure and may interfere with the appearance. There was room.

  The present invention has been proposed in view of the above-described circumstances, and improves the fixing performance of the reinforcing member, reliably increases the shear load resistance of the reinforced concrete structure, and can improve the workability. It aims at providing the shear reinforcement structure of an object.

  The shear reinforcement structure for a reinforced concrete structure according to the present invention has the following features in order to achieve the above-described object. That is, a shear reinforcement structure for a reinforced concrete structure according to the present invention includes a reinforcement member insertion hole drilled from one surface of the reinforced concrete structure toward the other side, a reinforcement member inserted into the reinforcement member insertion hole, and a reinforcement member It consists of a filler that fills the insertion hole.

  The reinforcing member insertion hole is located on the back side in the insertion direction of the reinforcing member, on the near side in the insertion direction of the reinforcing member and in the concrete covering thickness of the existing main reinforcement, and on the back side insertion hole And an enlarged-diameter insertion hole having an inner diameter larger than the inner diameter. The reinforcing member is connected to the main body part, the first fixing body provided at both ends of the main body part, and the first fixing body on the near side in the insertion direction (the surface side of the reinforced concrete structure) by the connection part. And a second fixing member disposed in the vicinity of the existing reinforcing bar in the enlarged diameter insertion hole. Further, the thickness of the connection portion is smaller than that of the main body portion, and the maximum diameter of the second fixing body is twice or more the maximum diameter of the main body portion.

  In the shear reinforcement structure for a reinforced concrete structure having the above-described configuration, the reinforcing member is equivalent to the diameter of the first fixing body between the first fixing body and the second fixing body, and the second fixing body. It is possible to include a first fixing body, a second fixing body, and a third fixing body connected by connecting portions, each having a maximum diameter smaller than the maximum diameter. In this case, the thickness of each connection portion for connecting each fixing body is gradually reduced from the connection side to the main body portion toward the second fixing body side.

  In the shear reinforcement structure for a reinforced concrete structure having the above-described structure, it is preferable that at least the fixing body other than the first fixing body is subjected to a rust prevention treatment on the surface thereof.

  According to the shear reinforcement structure of a reinforced concrete structure according to the present invention, the reinforcing member is positioned in the near side of the existing reinforcing bar and in the concrete covering thickness of the existing main reinforcing bar in the insertion direction of the reinforcing member. A diameter-enlarged insertion hole having an inner diameter larger than the inner diameter is provided, and a second fixing body having a diameter more than twice the maximum diameter of the main body portion of the reinforcing member is disposed in the diameter-enlarged insertion hole. is there.

  Accordingly, not only can the fixing performance of the reinforcing member be improved, but the degree of freedom of the position where the fixing body is arranged on the surface side of the reinforced concrete structure is increased, so that it is possible to design flexibly according to the situation. It becomes.

  Further, since the second fixing body is disposed within the concrete covering thickness of the existing main reinforcement and in the vicinity of the existing main reinforcement, the fixing body protrudes from the surface of the reinforced concrete structure and becomes obstructive. It doesn't get worse.

  In addition, the thickness of the connection part for connecting the fixing body is made thinner than that of the main body part, and further, the thickness of each connection part for connecting each fixing body is successively made thinner from the connection side of the main body part, thereby fixing. While reducing the amount of material used for the body, it is possible to reduce the weight of the reinforcing member. In the fixing body, when the connection side to the reinforcing bar is compared with the surface side of the reinforced concrete structure, the pulling force applied to the fixing body is smaller on the surface side of the reinforced concrete structure. there is no problem.

  Moreover, corrosion of a reinforcement member can be effectively prevented by performing a rust prevention process on the surface of the fixing body located on the surface side of the reinforced concrete structure. In particular, when the concrete covering thickness is small at the position where the fixing body is disposed, the rust prevention treatment is effective.

The schematic diagram (Example 1) of the shear reinforcement structure of the reinforced concrete structure which concerns on this invention. The schematic diagram (Example 2) of the shear reinforcement structure of the reinforced concrete structure which concerns on this invention. The side view of the state which decomposed | disassembled each member which comprises a reinforcement member. The top view of the state which decomposed | disassembled each member which comprises a reinforcement member.

  Hereinafter, an embodiment of a shear reinforcement structure of a reinforced concrete structure according to the present invention (hereinafter abbreviated as a shear reinforcement structure) will be described with reference to the drawings. 1 to 4 illustrate a shear reinforcement structure according to an embodiment of the present invention. FIGS. 1 and 2 are schematic views of the shear reinforcement structure, FIG. 3 is a side view of the reinforcement member, and FIG. It is a top view of the state which decomposed | disassembled each member to comprise. In FIG. 4, the first fixing member and the second fixing member are viewed from the connection side to the main body, and the main body is viewed from the connection side to the first fixing member.

<Outline of shear reinforcement structure>
As shown in FIGS. 1 and 2, the shear reinforcement structure according to the embodiment of the present invention includes a reinforcement member insertion hole 20 drilled from one surface of the reinforced concrete structure 10 toward the other side, and a reinforcement member insertion hole 20. The reinforcing member 30 is inserted into the reinforcing member insertion hole 20 and is filled with a filler (not shown). The shape of the reinforcing member insertion hole 20 and the fixing members 32, 33, 34 of the reinforcing member 30 are It has characteristics in structure.

<Reinforcing member insertion hole>
The reinforcing member insertion hole 20 is a non-through hole, and as shown in FIGS. 1 and 2, a back side insertion hole 21 positioned on the back side in the insertion direction of the reinforcing member 30, a near side in the insertion direction of the reinforcing member 30, and It is located within the concrete covering thickness of the existing main reinforcement 41 and has an enlarged insertion hole 22 having an inner diameter larger than the inner diameter of the inner insertion hole 21.

  The back side insertion hole 21 is a hole for inserting the distal end side of the reinforcing member 30 in the inserting direction, and the main body 31 and the first fixing body 32 of the reinforcing member 30 are inserted therein. Therefore, the inner diameter of the back insertion hole 21 is larger than the maximum outer diameter of the main body 31 of the reinforcing member 30 and the first fixing body 32. The back side insertion hole 21 is drilled from one side of the reinforced concrete structure 10 to be reinforced toward the other side. And the front-end | tip part (inner side of the reinforced concrete structure 10) of the back side insertion hole 21 is located in the near side of the existing main reinforcement 42 of the back side.

  The enlarged diameter insertion hole 22 is located on the near side in the insertion direction of the reinforcing member 30 and within the concrete covering thickness of the existing main reinforcement 41 and has an inner diameter larger than the inner diameter of the rear side insertion hole 21. A second fixing member 33 is disposed in the insertion hole 22.

<Reinforcing member>
As shown in FIGS. 1 to 4, the reinforcing member 30 includes a main body 31, first fixing bodies 32 provided at both ends of the main body 31, and a first fixing body 32 on the near side in the insertion direction. And a second fixing member 33 disposed in the enlarged diameter insertion hole 22.

<Main body>
The main body 31 is formed of, for example, a deformed reinforcing bar, and is formed with a male threaded portion (tapered threaded portion) 31a having a diameter reduced toward the distal end while being plastically processed at the end.

<First fixing body>
The first fixing body 32 is a fixing body provided at both ends of the main body 31. The reinforcing member 30 provided with the main body 31 and the first fixing body 32 is described in, for example, Japanese Patent No. 4395191. That is, as for the reinforcing bar which is the main-body part 31, the front-end | tip part is processed in the taper shape, and the external thread part (tapered thread part) 31a is further formed in the outer peripheral surface. The reinforcing bars are preferably subjected to plastic hardening at least at the base end portion of the male screw portion (tapered screw portion) 31a. Thus, by performing the plastic hardening process on the end portion of the reinforcing bar, the apparent yield point is increased as compared with that before processing, and the strength of the end portion of the reinforcing bar can be increased.

  As shown in FIGS. 3 and 4, the first fixing body 32 has a nut shape having an outer diameter larger than the outer diameter of the main body portion 31, and has a female screw portion for assembling the male screw portion 31 a. 32a is formed. As described above, since the male screw portion 31a is reduced in diameter toward the distal end portion, the female screw portion 32a is also reduced in diameter toward the distal end portion. Further, a spanner engaging surface for engaging a rotating jig such as a spanner is formed on the outer peripheral surface of the first fixing body 32. Further, a connection female screw portion 32 b for assembling a connection male screw portion 35 a provided in the connection portion 35 is provided on the tip end side (the side opposite to the main body portion 31) of the first fixing body 32.

<Second fixing body>
As shown in FIGS. 1 and 2, the second fixing body 33 is a fixing body for being disposed in the enlarged diameter insertion hole 22, and is located on the near side (surface side of the reinforced concrete structure 10) in the insertion direction. The first fixing body 32 is connected to the first fixing body 32 via the connection portion 35. The maximum diameter of the second fixing body 33 is set to be twice or more the maximum diameter of the main body 31. The second fixing body 33 shown in FIGS. 1 and 2 has a maximum diameter 2D that is twice the maximum diameter D of the reinforcing bar. Further, a spanner engaging surface for engaging a rotating jig such as a spanner is formed on the outer peripheral surface of the second fixing member 33. Further, on the base end side (main body part 31 side) of the second fixing body 33, a connection male screw part 35 a for assembling to the connection female screw part 32 b provided on the first fixing body 32 is provided. In the example shown in FIGS. 3 and 4, the second fixing body 33 and the connecting portion 35 are integrated, and the whole is a bolt shape.

  Further, as shown in FIGS. 1 and 2, the second fixing body 33 is provided with a concrete cover of the existing main reinforcing bar 41 (the existing reinforcing bar disposed on the surface side of the reinforcing member 30) in the insertion direction of the reinforcing member 30. It is installed within the thickness so as to be located in the vicinity of the existing reinforcing bar 41. The vicinity of the existing reinforcing bar 41 disposed on the surface side of the reinforcing member 30 is, for example, a position separated by 40 mm or more from the surface of the concrete structure. That is, the second fixing body 33 is disposed such that the front end surface (surface on the surface side of the concrete structure) is sufficiently separated from the surface of the concrete structure.

<Third fixing body>
As shown in FIG. 1, the third fixing member 34 is equivalent to the diameter of the first fixing member 32 between the first fixing member 32 and the second fixing member 33, and the second fixing member 34. The fixing body has a maximum diameter smaller than the maximum diameter of 33 and is connected to the first fixing body 32 and the second fixing body 33 by connection portions 35 and 36, respectively. By providing the third fixing body 34, there are three stages of fixing bodies on the surface side of the reinforced concrete structure 10. The third fixing body 34 may be formed so as to be integrated with the second fixing body 33 or may be formed separately from the second fixing body 33. In any case, a connection male screw portion (not shown) for assembling to the connection female screw portion 32b provided in the first fixing body 32 is provided on the base end portion side located on the main body portion 31 side. is there.

<Connection part>
As shown in FIGS. 1 and 2, a connecting portion 35 for connecting the first fixing body 32 and the second fixing body 33, a third fixing body 34 and the first fixing body 32 or the second fixing body. The thickness (diameter) of the connecting portion 36 for connecting 33 is smaller than that of the main body portion 31. Furthermore, the thicknesses (diameters) of the connection portions 35 and 36 that connect the fixing bodies 32, 33, and 34 gradually decrease from the connection side of the main body portion 31 toward the second fixing body 33 side.

  That is, when the fixing body has two stages (when only the first fixing body 32 and the second fixing body 33 are provided), the thickness (diameter) of the connecting portion 35 is the maximum outer diameter of the main body portion 31. It is thinner than. Further, when the number of fixing members is three (when the first fixing member 32, the second fixing member 33, and the third fixing member 34 are provided), the thickness (diameter) of each connection portion 35, 36 is provided. Is thinner than the maximum outer diameter of the main body 31 and the thickness (diameter) of the connecting portion 35 connecting the third fixing body 34 and the second fixing body 33 is the third fixing body. It is thinner than the thickness (diameter) of the connecting portion 36 that connects 34 and the first fixing body 32.

<Rust prevention treatment>
Fixing bodies (second fixing body 33 and third fixing body 34) other than the first fixing body 32 existing deeply from the surface side of the concrete structure (thickness of the concrete cover) are protected against the surface. Rust treatment is preferably performed. In the shear reinforcement structure of the reinforced concrete structure 10 of the present invention, the tip surface (surface on the surface side of the concrete structure) of the second fixing body 33 is disposed so as to be separated from the surface of the concrete structure. The third fixing member 34 is disposed deeper than the second fixing member 33.

  Therefore, even when the second fixing body 33 and the third fixing body 34 are formed of metal (for example, iron), there is a low possibility that rust is generated due to moisture entering from the surface of the concrete structure. However, in this embodiment, even if moisture or the like enters from the surface of the concrete structure, rust is prevented from occurring in the second fixing body 33 and the third fixing body 34 in advance. Therefore, these fixing bodies are subjected to rust prevention treatment. This rust prevention treatment is not essential, and the first fixing body 32 may be subjected to rust prevention treatment.

<Filler>
Although not shown, the filler is a member for filling the reinforcing member insertion hole 20 in which the reinforcing member 30 is inserted, and the injection time is before or after the reinforcing member 30 is inserted into the reinforcing member insertion hole 20. It may be at any point after. As the filler, mortar or resin adhesive can be used.

<Example 1>
In Example 1, a three-stage fixing body exists on the surface side of the reinforced concrete structure 10. That is, as shown in FIG. 1, the reinforcing member insertion hole 20 is drilled from the surface side of the reinforced concrete structure 10 to the front side of the existing reinforcing bar 42 located on the back side. As described above, the reinforcing member insertion hole 20 has a depth side insertion hole 21 located on the back side in the insertion direction of the reinforcing member 30, a near side in the insertion direction of the reinforcing member 30, and within the concrete covering thickness of the existing main reinforcement 41. And an enlarged diameter insertion hole 22 having an inner diameter larger than the inner diameter of the back side insertion hole 21.

  When the second fixing body 33 and the third fixing body 34 are formed separately, the first fixing body 32 is assembled to both ends of the main body 31 and the front side in the insertion direction (reinforced concrete structure). The third fixing body 34 is assembled to the surface 10 of the object 10 through the connection portion 36, and the second fixing body 33 is assembled through the connection portion 35. When the second fixing body 33 and the third fixing body 34 are integrated, the first fixing body 32 is assembled to both ends of the main body 31 and the front side in the insertion direction (reinforced concrete structure). The second fixing body 33 and the third fixing body 34 are assembled to the surface 10 of the object 10 via the connection portion 36.

  In the first embodiment, the second fixing body 33 is within the concrete covering thickness of the existing main reinforcing bar 41 (the existing reinforcing bar disposed on the surface side of the reinforcing member 30) on the near side in the insertion direction of the reinforcing member 30, and It is installed so as to be located in the vicinity of the existing reinforcing bar 41. Further, the third fixing body 34 is disposed at substantially the same position as the near side in the insertion direction of the reinforcing member 30 and the existing main reinforcing bar 41 (the existing reinforcing bar disposed on the surface side of the reinforcing member 30). Then, before or after the reinforcing member 30 is inserted into the reinforcing member insertion hole 20, the reinforcing member insertion hole 20 is filled with a filler to close the reinforcing member insertion hole 20.

<Example 2>
In Example 2, a two-stage fixing body exists on the surface side of the reinforced concrete structure 10. That is, as shown in FIG. 2, the reinforcing member insertion hole 20 is drilled from the surface side of the reinforced concrete structure 10 to the front side of the existing reinforcing bar 42 located on the back side. As described above, the reinforcing member insertion hole 20 has a depth side insertion hole 21 located on the back side in the insertion direction of the reinforcing member 30, a near side in the insertion direction of the reinforcing member 30, and within the concrete covering thickness of the existing main reinforcement 41. And an enlarged diameter insertion hole 22 having an inner diameter larger than the inner diameter of the back side insertion hole 21.

  In Example 2, the second fixing member 33 is within the concrete covering thickness of the existing main reinforcing bar 41 (the existing reinforcing bar disposed on the surface side of the reinforcing member 30) on the near side in the insertion direction of the reinforcing member 30, and It is installed so as to be located in the vicinity of the existing reinforcing bar 41. Then, before or after the reinforcing member 30 is inserted into the reinforcing member insertion hole 20, the reinforcing member insertion hole 20 is filled with a filler to close the reinforcing member insertion hole 20.

DESCRIPTION OF SYMBOLS 10 Reinforced concrete structure 20 Reinforcement member insertion hole 21 Back side insertion hole 22 Expanded diameter insertion hole 30 Reinforcement member 31 Main body part 31a Male thread part 32 First fixing body 32a Female thread part 32b Connection female thread part 33 Second fixing body 34 Third fixing member 35, 36 Connection portion 35a Connection male screw portion 41, 42 Existing main reinforcement

Claims (3)

A reinforcing member insertion hole drilled from one surface of the reinforced concrete structure toward the other side, a reinforcing member inserted into the reinforcing member insertion hole, and a filler filled in the reinforcing member insertion hole,
The reinforcing member insertion hole is located on the back side in the insertion direction of the reinforcing member, on the near side in the insertion direction of the reinforcing member and in the concrete covering thickness of the existing main reinforcement, and on the back side An enlarged diameter insertion hole having an inner diameter larger than the inner diameter of the insertion hole,
The reinforcing member is connected to the main body portion, the first fixing body provided at both ends of the main body portion, and the first fixing body on the near side in the insertion direction by the connecting portion, and the enlarged diameter insertion hole. A second fixing member disposed in the vicinity of the existing reinforcing bar,
The thickness of the connection part is thinner than the main body part,
The maximum diameter of the second fixing body is at least twice the maximum diameter of the main body.
A shear reinforcement structure for reinforced concrete structures. The reinforcing member has a maximum diameter between the first fixing body and the second fixing body that is equal to the diameter of the first fixing body and smaller than the maximum diameter of the second fixing body. And a third fixing member connected to each of the first fixing member and the second fixing member by a connecting portion,
The thickness of each connection portion for connecting each fixing body is gradually reduced from the connection side to the main body portion toward the second fixing body side.
The shear reinforcement structure for a reinforced concrete structure according to claim 1. At least the fixing body other than the first fixing body has a surface subjected to rust prevention treatment,
The shear reinforcement structure for a reinforced concrete structure according to claim 1 or 2.

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