JP2010090574A - Structure and method for anchoring reinforcement to reinforced concrete structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure and a method for anchoring reinforcements to a reinforced concrete structure, which can be applied even to a location disabling the application of a semicircular hook, which can minimize damage to a structure by making a drilled hole diameter smaller than in the case of mechanical anchorage, and which can reduce the used amount of a filler. <P>SOLUTION: This structure includes the one set of reinforcements 10 which are arranged almost in parallel, and a connecting member 20 which is attached to an end of each of the reinforcements 10 so as to integrally connect the reinforcements 10 together. The connecting member 20 includes connecting portions 21 which face the reinforcements 10 to be connected together, respectively, and a body portion 22 which is laid between the respective connecting portions 21. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a structure and a method for fixing a reinforcing bar to a reinforced concrete structure, and more particularly to a reinforcing bar fixing structure and a fixing method suitable for reinforcement work of an existing concrete structure.

  In recent years, there is a growing need for seismic reinforcement for existing reinforced concrete structures in the face of concerns about the occurrence of large-scale earthquakes. When the existing reinforced concrete structure has insufficient shear load capacity, it is necessary to increase the shear load capacity of the structure by adding a reinforcing steel material in a direction crossing the main reinforcing bar. In such a reinforcement work, it is necessary that the reinforcing member is firmly fixed, and it is required that the existing structure is minimized and can be easily constructed.

  In the conventional general fixing structure, a semicircular hook is embedded in the structure. However, it has been difficult to insert such a semicircular hook structure into an insertion hole provided in the structure during reinforcement work. Therefore, various structures for fixing reinforcing bars to existing reinforced concrete structures have been proposed.

  For example, a technique for ensuring a predetermined pulling rigidity is disclosed for an existing reinforced concrete structure on which a shearing force acts (see Patent Document 1). The technique described in Patent Document 1 includes a step of drilling a reinforcing member insertion hole for installing a shear reinforcing member through an intermediate wall of an existing reinforced concrete structure, and a filler in the reinforcing member insertion hole. By inserting the step of filling, the shear reinforcing bar and the base plate head provided at the base end thereof into the reinforcing member insertion hole, and fixing the tip plate head to the tip of the shear reinforcing bar, Disposing a shear reinforcement member inside the intermediate wall. In this technique, a fixing body (tip plate head) having a diameter of 2.5 times or more the diameter of the reinforcing bar is attached to the tip of the shear reinforcing reinforcing bar by welding, friction welding, high frequency heating or the like. .

JP 2006-57265 A

  However, since the fixing structure consisting of the conventional semicircular hook structure has a semicircular hook, the semicircular hook may not be inserted into the insertion hole provided in the structure during the reinforcement work. Difficult to apply to In addition, in the new construction, the semicircular hook structure has a problem that not only the fixing of the fixing portion is complicated, but also the construction is difficult when the semicircular hook is hooked on the orthogonal reinforcing bars.

  The prior art described in Patent Document 1 uses a fixing body (tip plate head) having a diameter of 2.5 times or more the diameter of the reinforcing bar, and therefore the perforation diameter is increased by the amount of the fixing body. As damage is increased, the amount of filler used increases, and construction costs increase.

  The present invention has been proposed in order to solve the various problems described above, and can be applied even in a place where a semicircular hook cannot be applied. An object of the present invention is to provide a fixing structure and a fixing method of a reinforcing bar to a reinforced concrete structure that is small, can minimize damage to the structure, and can reduce the amount of filler used.

In order to achieve the above-mentioned object, the fixing structure and fixing method for reinforcing bars to a reinforced concrete structure according to the present invention have the following features.
That is, the fixing structure of the reinforcing bar to the reinforced concrete structure according to the present invention includes a pair of reinforcing bars arranged substantially in parallel and a connecting member that is attached to an end of each reinforcing bar and integrally connects the reinforcing bars. . And a connection member consists of a connection part respectively opposed to each rebar to connect, and a main-body part spanned between each connection part, It is characterized by the above-mentioned.

  Further, in addition to the above-described configuration, the reinforcing bar has a tapered screw portion formed by cutting into a taper shape after the end portion is plastic-cured, and the connecting portion of the connecting member is formed at the end portion of the reinforcing bar. It is preferable to have a female screw portion that is screwed onto the taper screw portion.

  The method of fixing a reinforcing bar to a reinforced concrete structure according to the present invention includes a step of forming an insertion hole for inserting a reinforcing bar and a fixing body in the reinforced concrete structure, and the reinforcing bar and a connecting member in the insertion hole. And a step of injecting a filler into the insertion hole at any time before or after insertion of the reinforcing bar and the connecting member into the insertion hole and connecting the connecting member to the end of the reinforcing bar. , Including. The reinforcing bars are composed of a pair arranged substantially in parallel, and the connecting member includes connecting members that are attached to the ends of the reinforcing bars and integrally connect the reinforcing bars, and the connecting members are respectively connected to the reinforcing bars to be connected. It consists of an opposing connection part and a main-body part spanned between each connection part.

  Moreover, in the fixing method of the reinforcing bar to the above-mentioned reinforced concrete structure, the insertion hole can be formed separately corresponding to the outer diameter of each reinforcing bar.

  According to the fixing structure and fixing method of a reinforcing bar to a reinforced concrete structure according to the present invention, since a pair of reinforcing bars and a connecting member formed separately from the reinforcing bars are used, the reinforcing bars are inserted into the insertion holes. After that, by connecting the connecting member to the end of the reinforcing bar, it is possible to fix the reinforcing bar even at a location where the semicircular hook cannot be applied.

  Further, the end portion of the reinforcing bar is plastic-cured and then cut into a tapered shape to form a tapered screw portion, thereby increasing the strength of the end portion of the reinforcing bar and improving the fixing performance.

  Further, by forming the reinforcing bar insertion holes separately corresponding to the outer diameters of the reinforcing bars, the cross-sectional area of the insertion holes can be reduced, and a sufficient covering thickness can be secured. In addition, since the cross-sectional area of the insertion hole is small, the amount of filler used can be reduced.

<Overview>
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a fixing structure and fixing method for reinforcing bars to a reinforced concrete structure according to the present invention will be described with reference to the drawings.
In the fixing structure and fixing method of a reinforcing bar to a reinforced concrete structure according to the present invention, a set of reinforcing bars arranged substantially in parallel, and a connecting member that is attached to an end of each reinforcing bar and integrally connects the reinforcing bars are provided. Yes. Moreover, a connection member consists of the connection part respectively opposed to each rebar to connect, and the main-body part spanned between each connection part.

<Fixing structure>
FIG. 1 is a schematic plan view of a reinforcing bar fixing structure to a reinforced concrete structure according to an embodiment of the present invention.
As shown in FIG. 1, the fixing structure of a reinforcing bar to a reinforced concrete structure according to an embodiment of the present invention is configured by connecting connecting members 20 to both ends of a pair of reinforcing bars 10 arranged substantially in parallel. It has a fixing structure.
The reinforcing bar 10 used in the present embodiment is used for a general concrete structure, and for example, a different diameter reinforcing bar can be used. Further, the end portion of the reinforcing bar 10 is subjected to plastic hardening treatment, and a tapered taper screw portion 11 is formed.

  Although not shown in detail, the jig for performing the plastic hardening process on the end of the reinforcing bar 10 is divided into two parts so as to sandwich the reinforcing bar 10, and each jig has a protruding part protruding inward. Have. And in the state which combined the jig | tool, the distance between the convex parts which oppose is substantially equal to the outer diameter of the reinforcing bar 10 after a plastic hardening process, and the distance of other places is the outside of the reinforcing bar 10 before a plastic hardening. It is approximately equal to the diameter.

<Plastic hardening treatment>
In order to perform the plastic hardening process on the end portion of the reinforcing bar 10, a jig is attached to a portion to be processed, and the jig is clamped by a press to apply pressure. As a press machine used for the plastic hardening treatment, a publicly known small-sized press machine that is generally widespread can be used. When the plastic hardening treatment is performed in this manner, the apparent yield point increases as compared to before processing, and the strength of the end portion of the reinforcing bar 10 can be increased.

<Threading>
A taper screw portion 11 is formed on the end portion of the rebar 10 that has been subjected to the plastic hardening process by performing screw processing in which the screwing direction is reversed. That is, the screw at one end of the reinforcing bar 10 is a reverse screw. This threading can be performed using a known cutting machine such as a lathe. In this embodiment, the taper screw part 11 is formed by cutting in a taper shape toward the front-end | tip part from the location where the plastic hardening process was performed.
In addition, it is preferable to perform the plastic hardening process mentioned above only to the base end part of the taper screw part 11. FIG. In this way, by performing plastic hardening treatment only on the base end portion of the taper screw portion 11, a jig or a press for performing the plastic hardening treatment can be further downsized.

<Connecting member>
As shown in FIG. 1, the connecting member 20 is a member having a substantially U-shaped cross section, and includes a connecting portion 21 that faces each reinforcing bar 10 to be connected, and a main body portion 22 that spans between the connecting portions 21. Become. In addition, the connection portion 21 is formed with a female screw portion 23 that is screwed to the taper screw portion 11 formed at the end of the reinforcing bar 10 in accordance with the screwing direction of each taper screw portion 11. In order to configure the fixing structure using the connecting member 20 having such a shape, the connecting member is positioned at both ends of the pair of reinforcing bars 10 and each reinforcing bar 10 is rotated in the screwing direction.

Further, as another embodiment of the connecting member, one having the structure shown in FIG. 2 or 3 can be used. 2 and 3 are schematic plan views showing other embodiments of the connecting member.
The connecting members 120a and 120b shown in FIG. 2 are provided with connecting portions 121 for connecting to the reinforcing bars 10 independently, and after connecting the connecting portions 121 to the ends of the reinforcing bars 10, the connecting portions 121 are connected to each other. And unite. That is, the connecting members 120a and 120b shown in FIG. 2 have a divided structure, and the fixing portion is formed by attaching the connecting portion 121 to the end of each reinforcing bar 10 and integrating the divided connecting portions 121 together. .

Each of the connecting members 120a and 120b has a two-part structure, and has a connecting portion 121 for connecting to each reinforcing bar 10. Further, one connecting portion 121 is provided with a connecting projection 124 protruding toward the other connecting portion 121, and the other connecting portion 121 is provided with a mechanism for locking the connecting projection 124. . The connecting protrusion 124 increases in diameter from the base end portion toward the central portion and decreases in diameter from the central portion toward the distal end portion. The mechanism for locking the connection protrusion 124 includes a recess 125, a wedge member 126 provided in the recess 125, and a spring 127 that presses the wedge member 126 toward the opening side of the recess 125. The wedge member 126 has a shape that is reduced in diameter toward the opening side of the recess 125 in a state where the connection protrusion 124 is not locked, and the recess 126 resists the biasing force of the spring 127 as the connection protrusion 124 enters. When it moves toward the back of 125, the space | interval by the side of a front-end | tip part will spread, and the front-end | tip part of the connection protrusion 124 will be received. When the central portion of the wedge member 126 of the connection protrusion 124 passes, the wedge member 126 is pushed back to the opening side of the recess 125 by the biasing force of the spring 127 to receive the connection protrusion 124, and the connection protrusion 124 is engaged in the recess 125. Can be stopped.
Each connecting portion 121 is provided with a female screw portion 123 for screwing the taper screw portion 11 of the reinforcing bar 10.

  The connection members 220a and 220b shown in FIG. 3 are each provided with a connection part 221 for connecting to each reinforcing bar 10, and after connecting the connection part 221 to the end of the reinforcing bar 10, the connection parts 221 are connected to each other. And unite. That is, the connecting members 220a and 220b shown in FIG. 3 have a divided structure, and the fixing portion is formed by attaching the connecting portions 221 to the end portions of the reinforcing bars 10 and integrating the divided connecting portions 221 together. .

This connecting member 220 has a two-part structure, and has a connecting portion 221 for connecting to each reinforcing bar 10. In addition, each connection portion 221 is provided with a bolt insertion hole 224 that becomes a series when the connection portion 221 is integrated. Then, connecting portions 221 are attached to the end portions of the reinforcing bars 10, bolts 225 are successively inserted into the bolt insertion holes 224 provided in the connecting portions 221, and nuts 226 are screwed onto the tip ends of the bolts 225. The fixing structure is formed by integrating the portion 221.
Each connection portion 221 is provided with a female screw portion 223 for screwing the taper screw portion 11 of the reinforcing bar 10.

<Method of fixing reinforcing bars to reinforced concrete structures>
The fixing method of the reinforcing bar to the reinforced concrete structure according to the embodiment of the present invention includes, as a basic process, forming an insertion hole for inserting the reinforcing bar 10 and the connecting member 20 into the reinforced concrete structure; The step of inserting the reinforcing bar 10 and the connecting member 20 into the insertion holes 30, 130a, 130b (see FIGS. 4 and 5), and the insertion of the reinforcing bar 10 and the connecting member 20 into the insertion holes 30, 130a, 130b or before the insertion. And a step of injecting filler into the insertion holes 30, 130 a, 130 b at any later time and connecting the connecting member 20 to the end of the reinforcing bar 10.

<Insertion hole>
With reference to FIG.4 and FIG.5, the insertion hole formed in a reinforced concrete structure is demonstrated. 4 and 5 are schematic cross-sectional views showing the shape of the insertion hole.
The example shown in FIG. 4 is a one-hole type in which the entire fixing structure is inserted into one insertion hole 30. That is, the one-hole type insertion hole 30 forms one insertion hole 30 having a diameter larger than the maximum diameter of the fixing structure in which the reinforcing bar 10 and the connecting member 20 are integrated, and the fixing structure is formed in the insertion hole 30. Is supposed to be inserted. This one-hole type insertion hole 30 can be formed quickly because the insertion hole 30 can be formed in a single drilling step.

The example shown in FIG. 5 is a two-hole type in which separate insertion holes 130 a and 130 b are formed corresponding to the outer diameters of the reinforcing bars 10. That is, in the two-hole type insertion holes 130a and 130b, the insertion holes 130a and 130b having a diameter larger than the maximum diameter of each reinforcing bar 10 are formed for each reinforcing bar 10, and the reinforcing bars 10 are respectively placed in the insertion holes 130a and 130b. It is supposed to be inserted. The two-hole type insertion holes 130a and 130b can reduce the cross-sectional area of the insertion hole as compared with the one-hole type, and can ensure a sufficient covering thickness. Moreover, since the cross-sectional area of the insertion hole is small, the amount of filler used can be reduced.
Which type of insertion hole is to be formed can be appropriately selected according to the configuration or state of the reinforced concrete structure to be constructed.

<Other embodiments>
The fixing structure and fixing method of reinforcing bars to the reinforced concrete structure of the present invention are not limited to the above-described embodiments, and can be implemented with appropriate modifications. For example, instead of using a pair (two) of reinforcing bars 10, three or more reinforcing bars 10 may be used as one set. In this case, connection portions 21 corresponding to the number of reinforcing bars 10 are formed on the connecting member 20.
Moreover, instead of attaching the connecting member 20 to both ends of the reinforcing bar 10, the connecting member 20 may be attached to only one of the ends depending on the configuration or state of the reinforced concrete structure to be constructed.
Further, in the above-described embodiment, the reinforcing bar 10 and the connecting member 20 are connected by a taper screw structure, but may be connected using a general screw structure, or connected using a technique such as friction welding. May be.

<Comparison with conventional technology>
As described above, in the fixing structure and fixing method of the reinforcing bar to the reinforced concrete structure according to the present invention, the reinforcing bar is inserted into the insertion hole formed in the reinforced concrete structure, and the connecting member is connected to the end of the reinforcing bar. Therefore, it is possible to fix the reinforcing bar even at a location where the semicircular hook cannot be applied.

The plane schematic diagram of the fixation structure of the reinforcing bar to the reinforced concrete structure concerning the embodiment of the present invention. The plane schematic diagram which shows other embodiment of a connection member. The plane schematic diagram which shows other embodiment of a connection member. The cross-sectional schematic diagram which shows the shape of an insertion hole. The cross-sectional schematic diagram which shows the other shape of an insertion hole.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Reinforcing bar 11 Taper screw part 20 Connection member 21 Connection part 22 Main body part 23 Female screw part 30 Insertion hole 120a, 120b Connection member 121 Connection part 123 Female screw part 124 Connection protrusion 125 Concave part 126 Wedge member 127 Spring 130a, 130b Insertion hole 220a 220b connecting member 221 connecting portion 223 female screw portion 224 bolt insertion hole 225 bolt 226 nut

Claims (4)

A fixing structure for fixing a reinforcing bar to a reinforced concrete structure,
A set of reinforcing bars arranged substantially in parallel, and a connecting member that attaches to the end of each reinforcing bar and connects the reinforcing bars together;
The connecting member includes a connecting portion facing each reinforcing bar to be connected, and a main body portion spanned between the connecting portions, and the reinforcing bar fixing structure to the reinforced concrete structure. The rebar has a taper screw portion formed by cutting into a tapered shape after plastic hardening of the end portion,
The reinforcing member fixing structure to the reinforced concrete structure according to claim 1, wherein the connecting portion of the connecting member has a female screw portion screwed into a taper screw portion formed at an end portion of the reinforcing bar. A fixing method for fixing a reinforcing bar to a reinforced concrete structure,
Forming an insertion hole for inserting a reinforcing bar and a connecting member with respect to a reinforced concrete structure;
Inserting the rebar and the connecting member into the insertion hole;
And a step of injecting a filler into the insertion hole at any time before or after insertion of the reinforcing bar and the connecting part into the insertion hole and connecting a connecting member to the end of the reinforcing bar. ,
The reinforcing bars consist of a set arranged substantially in parallel,
The connecting member includes a connecting member that is attached to an end of each reinforcing bar and integrally connects the reinforcing bars,
The connecting member includes a connecting portion facing each reinforcing bar to be connected, and a main body portion that spans between the connecting portions, and a method for fixing the reinforcing bar to the reinforced concrete structure.   The method of fixing a reinforcing bar to a reinforced concrete structure according to claim 3, wherein the insertion hole is formed separately corresponding to the outer diameter of each reinforcing bar.

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