JP6470988B2 - Post-construction anchor and post-construction anchor construction method - Google Patents

Description

  The present invention relates to a post-construction anchor used for reinforcing an existing structure and a construction method thereof.

Conventionally, an anchor formed by embedding an anchor bar having a taper portion whose cross-sectional area gradually increases toward the tip and a fixing plate portion having a cross-sectional area larger than the taper portion, and filling the hole with a filler. The structure is known (for example, refer to Patent Document 1).
With this anchor structure, when a pulling force acts on the anchor muscle, a supporting pressure is applied by which the tapered portion pushes up the filler. This supporting pressure becomes a wedge effect, making it difficult for the anchor muscle to come out, and the anchoring force of the anchor muscle is improved.

JP2013-11142A

  However, in the case of the anchor structure of the above-mentioned Patent Document 1, since the predetermined taper portion and the fixing plate portion are formed in advance on the anchor bar, the anchor angle is adjusted by adjusting the taper angle of the taper portion at the construction site. It was difficult to adjust the muscle fixing power.

  An object of the present invention is to provide a post-construction anchor and a post-construction anchor construction method capable of easily adjusting the fixing force.

In order to achieve the above purpose, the post-construction anchor according to the present application is
A post-construction anchor comprising a rod-shaped anchor body and a fixing body that is replaceably attached to the tip of the anchor body,
At the tip of the anchor body which is a steel rod-shaped member, a male screw formed by forging screw processing is formed,
The fixing body is formed with a screw hole having a female screw that can be screwed with a male screw of the anchor body,
The fixing body has a shape in which a cross-sectional area gradually increases from one end to the other end, and the anchor main body is attached to the one end side.

Since the anchor of the post-construction anchor having such a structure has a shape in which the cross-sectional area gradually increases from one end to the other end, for example, the solidified material filled in the insertion hole formed in the concrete structure is solidified. When the pulling force is applied to the construction anchor after the installation, the supporting pressure is applied to the solidified material from the tapered peripheral surface of the fixing body. When the solidifying material is pressed against the concrete structure so that the fixing body presses the solidifying material against the inner surface of the insertion hole, the frictional force between the solidifying material and the concrete structure increases due to the wedge effect of the supporting pressure. Thus, the fixing strength of the post-construction anchor can be obtained by effectively using the strength of the concrete structure.
In particular, since the fixing body is replaceably attached to the tip of the anchor body, for example, several fixing bodies having different taper angles and shapes are prepared in advance, and depending on the location where the post-installation anchor is installed. By replacing the fixing body with an appropriate taper angle and shape, the fixing force of the post-installed anchor can be easily adjusted.
Further, if the male screw of the anchor body is screwed into the screw hole of the fixing body, the post-construction anchor can be assembled. That is, since the fixing member can be easily attached and detached, the fixing member can be easily replaced.
In addition, the outer diameter of the male screw formed by forging screw processing can be made larger than the diameter of the anchor body. By forming the male thread of the anchor body to which the fixing body is attached relatively thick by forging screw processing, even if the fixing body and the anchor body are screwed together, the cross-sectional area of the threaded portion may be Since it does not become smaller than the area, the strength as an anchor does not decrease, and a fixing force suitable as an anchor can be exhibited.

Also, preferably
Before Symbol state where the fixing member to the anchor body is attached, and as each of the outer peripheral surface at the boundary portion between the anchor body and the fixing member are continuous.

If post installed anchors each of the peripheral surface at the boundary between the anchors body and the fixing member are continuous, for example, if the force pulling the post installed anchors installed in concrete structures is applied, one end of the fixing member There will be no load.
In other words, if the anchor is constructed after each peripheral surface is continuous at the boundary between the anchor body and the fixing body, no load is applied to one end of the fixing body, and the fixing body is prevented from being damaged. Therefore, the fixing force of the post-installed anchor does not decrease due to deformation of the fixing body.

Also, preferably
A buffer member is provided to cover a boundary portion between the anchor body and the fixing body.

If a buffer member is provided so as to cover the boundary between the anchor body and the fixing body, for example, a large load is applied to one end of the fixing body even if a pulling force is applied to the construction anchor after it is installed in a concrete structure. There is no damage to the fuser. If one end of the fixing body is damaged and deformed by the load, the fixing force of the post-installed anchor may be reduced. However, by providing a buffer member that covers the boundary portion, a load is applied to one end of the fixing body. This can be prevented and deformation of the fixing body can be prevented.
In addition, by providing a buffer member that covers the boundary portion, foreign matter can be prevented from entering the gap between the anchor body and the fixing body.

Also, preferably
A step is formed on the peripheral surface of the fixing body.

  If the fixing anchor is formed after unevenness is formed on the peripheral surface of the fixing body, for example, since the frictional force between the fixing body and the solidifying material increases when the fixing body is embedded in the solidifying material, post-construction Anchor fixing power can be improved.

Also, preferably
The other end of the fixing body is provided with a protrusion that narrows toward the opposite side of the anchor body.

  The post-construction anchor provided with such a protrusion has a shape that can be easily inserted into the solidified material before solidification. That is, it can be preferably used when the post-installation anchor is inserted into the insertion hole filled with the solidifying material and then the solidification material is solidified and the post-installation anchor is installed.

Moreover, the post-construction anchor construction method according to the present application is a post-construction anchor construction method in which the post-construction anchor having the protrusions is installed at a predetermined location,
Forming an insertion hole at a predetermined location;
Filling the insertion hole with a solidifying material;
Inserting the post-construction anchor into the insertion hole from the protrusion side before the solidified material is solidified;
It was made to have.

If it is a post-construction anchor with protrusions, it can be easily inserted into the solidified material before solidification. Therefore, after the post-construction anchor is inserted into the insertion hole filled with the solidified material, the solidified material is solidified and post-construction is performed. It can be preferably used in the construction method of the procedure for installing the anchor.
In particular, when the construction anchor is inserted into the solidified material from the projecting portion side having a sharp tip, bubbles are not pushed into the solidified material by the fixing body.
For example, when the construction anchor is inserted into the solidified material after the protrusions are not provided, bubbles may be pushed into the solidified material on the other end surface of the fixing body. If the solidified material is solidified in a state containing bubbles unnecessary for design, the fixing force of the post-installed anchor may not be obtained as designed, which is not preferable.
On the other hand, when inserting the post-construction anchor with protrusions into the solidified material, air bubbles will not be pushed into the solidified material, so the anchoring force of the post-constructed anchor should be stabilized as designed. Can do.

  ADVANTAGE OF THE INVENTION According to this invention, the construction method of the post-construction anchor and post-construction anchor which can adjust fixing force easily is obtained.

It is a side view (a) which shows the post-installation anchor of this embodiment, the side view (b) which shows the anchor main body and fixing body which comprise a post-installation anchor, and the side view (c) which shows the fixing body of a different shape. . It is explanatory drawing (a) (b) which shows the procedure which installs a post-construction anchor in a predetermined location. It is explanatory drawing regarding control of the displacement amount of a post-construction anchor. It is a side view which shows a construction anchor after a buffer member is provided. It is a side view which shows a construction anchor after providing the fixing body in which the level | step difference was formed in the surrounding surface. It is a side view which shows a construction anchor after each surrounding surface has continued in the boundary part of an anchor main body and a fixing body. They are a side view (a) which shows a post-installation anchor provided with the fixing body provided with the projection part, and explanatory diagrams (b) and (c) showing a procedure for installing the post-construction anchor having the projection part.

  Hereinafter, embodiments of a post-construction anchor and a post-construction anchor construction method according to the present invention will be described in detail with reference to the drawings. However, the embodiments described below are given various technically preferable limitations for carrying out the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

FIG. 1A is a side view showing the post-construction anchor 10. FIG. 1B is a side view showing the anchor main body 1 and the fixing body 2 constituting the post-construction anchor 10.
As shown in FIG. 1, the post-installed anchor 10 of the present embodiment includes a rod-shaped anchor main body 1 and a fixing body 2 that is attached to the tip of the anchor main body 1 in a replaceable manner.

The anchor main body 1 is, for example, a PC steel rod, and a male screw 1 a is formed at the tip of the anchor main body 1. The male screw 1a is formed by forging screw processing.
The male screw 1 a formed by forging screw processing has an inner diameter (valley diameter) corresponding to the diameter of the anchor body 1, and the outer diameter of the male screw 1 a is larger than the diameter of the anchor body 1.

The fixing body 2 is a member made of, for example, steel, and has a shape in which a cross-sectional area gradually increases from one end 21 toward the other end 22. The fixing body 2 of the present embodiment has a truncated cone shape whose diameter increases from one end 21 toward the other end 22.
The fixing body 2 is formed with a screw hole 2a into which the anchor body 1 is screwed. The screw hole 2 a is a female screw formed so as to penetrate from the one end 21 of the fixing body 2 to the other end 22, and the anchor main body 1 is attached to the one end 21 side of the fixing body 2.
The fixing body 2 is structured to be screwed to the anchor main body 1, and the fixing body 2 can be easily attached and detached. Therefore, the fixing body 2 of the post-installed anchor 10 can be easily replaced.

As described above, the post-construction anchor 10 is used by attaching the fixing body 2 to the anchor main body 1.
In particular, since the fixing body 2 of the post-installed anchor 10 is a member that is replaceably attached to the male screw 1a of the anchor main body 1, for example, a frustum-shaped fixing having different taper angles as shown in FIG. The body 2 is prepared in advance, and the fixing body 2 having an appropriate shape can be selected and used depending on the location where the post-construction anchor 10 is installed.
Specifically, by using the fixing body 2 shown in FIG. 1C having a larger taper angle than the fixing body 2 shown in FIG. 1B, the pulling force acting on the post-construction anchor 10 (anchor body 1) is resisted. It is possible to improve the anchoring force of the anchor to be used.
That is, by preparing several frustum-shaped fixing bodies 2 with different taper angles in advance and replacing them with the fixing bodies 2 having an appropriate shape according to the location where the post-installation anchor 10 is installed, The fixing force can be easily adjusted.

  Further, since the male screw 1a of the anchor main body 1 to which the fixing body 2 is attached is formed relatively thick by forging screw processing, even if the fixing body 2 and the anchor main body 1 are screwed together, the anchor strength is high. It does not decrease, and can exhibit a fixing force suitable as an anchor.

  Next, a post-construction anchor construction method for installing the post-construction anchor 10 of the present embodiment at a predetermined location will be described.

First, as shown in FIG. 2A, an insertion hole H is formed at a predetermined location on the wall surface of the concrete structure C, and the fixing member 2 side of the post-construction anchor 10 is inserted into the insertion hole H.
Next, as shown in FIG. 2B, the solidification material G is filled into the insertion hole H. As the solidifying material G, for example, a grout material such as mortar or concrete can be used. In particular, in the case of the solidified material G having plasticity (thixotropic properties), the solidified material G filled in the insertion hole H is difficult to leak out, so that the solidified material G can be suitably solidified in the insertion hole H.
Then, after the solidifying material G is solidified, a fixing plate (not shown) that closes the insertion hole H is fixed to the anchor body 1.

The post-construction anchor 10 can be installed on the existing concrete structure C by such a procedure, and the concrete structure C can be reinforced by the post-construction anchor 10.
As shown in FIG. 2 (b), when a pulling force is applied to the construction anchor 10 after being installed in the concrete structure C, the supporting pressure P acting on the solidified material G from the tapered peripheral surface of the fixing body 2. Then, the supporting pressure P that presses the solidifying material G against the concrete structure C acts so that the fixing body 2 presses the solidifying material G against the inner surface of the insertion hole H. By the wedge effect of the support pressure P, the frictional force between the solidifying material G and the concrete structure C increases, and the strength of the concrete structure C is effectively used so that the fixing force of the post-construction anchor 10 is improved. It has become.

Moreover, if it is an anchor structure using the post-construction anchor 10 of this embodiment, control of the displacement amount by a preload will be attained.
For example, as shown in FIG. 3, when the load is applied to the construction anchor 10 once after being installed at a predetermined location and the displacement is advanced after the load is advanced, the displacement amount until the next load L is reached. Get smaller.
By performing such preloading, the displacement amount of the post-construction anchor 10 can be controlled so as to reach the high target load L with a small displacement amount.

Similarly, in the anchor structure using the post-construction anchor 10, the amount of displacement due to prestress can be controlled.
For example, if an expanding material is mixed with the solidified material G, prestress is introduced by the solidified material G, so that the amount of displacement until the target load L is reached becomes small.
That is, by inflating the solidified material G and introducing prestress into the post-construction anchor 10, the amount of displacement of the post-construction anchor 10 can be controlled so as to reach a high target load L with a small amount of displacement.

The present invention is not limited to the above embodiment.
For example, as shown in FIG. 4, a buffer member 3 that covers a boundary portion between the anchor main body 1 and the fixing body 2 in the post-construction anchor 10 may be provided.
At the boundary between the anchor body 1 and the fixing body 2, the edge of one end 21 of the fixing body 2 protrudes as a shoulder that is thicker than the anchor body 1, so that the buffer member 3 is provided so as to cover the shoulder. It has been. As the buffer member 3, for example, an O-ring made of butyl rubber can be used.

  For example, when a pulling force is applied to the construction anchor 10 after being installed in the concrete structure C, the shoulder portion of the fixing body 2 is the post-construction anchor 10 (see FIG. 1A) without the buffer member 3 provided. A load is applied to the one end 21. Since one end 21 of the fixing member 2 is relatively thin and relatively weak in strength, the one end 21 of the fixing member 2 may be damaged by a load. If the fixing body 2 is damaged and deformed, the fixing force of the post-construction anchor 10 may be reduced.

On the other hand, if the buffer member 3 covering the boundary portion between the anchor main body 1 and the fixing body 2 is provided, a large load is applied to the one end 21 of the fixing body 2 even when a pulling force acts on the post-installed anchor 10. Therefore, the one end 21 of the fixing body 2 is not damaged.
Further, if the buffer member 3 that covers the boundary portion between the anchor main body 1 and the fixing body 2 is provided, foreign matter such as a fragment of the solidified material G enters the gap between the anchor main body 1 and the fixing body 2. Deformation can be suppressed.

  Further, when the pulling force is applied to the construction anchor 10 after the buffer member 3 is not provided, the corner of the shoulder portion of the one end 21 of the fixing body 2 slightly damages the solidified material G. Although it may fall a little, if the buffer member 3 is provided, the solidified material G will not be damaged, and an excellent anchor structure can be maintained.

Thus, by providing the buffer member 3 that covers the boundary portion between the anchor main body 1 and the fixing body 2, it is possible to prevent a load from being applied to the one end 21 of the fixing body 2 and to prevent the fixing body 2 from being deformed. Therefore, it is preferable to attach the buffer member 3. Further, by providing the buffer member 3 that covers the boundary portion between the anchor body 1 and the fixing body 2, it is possible to prevent the solidifying material G from being loaded from the corner of the one end 21 of the fixing body 2 and damage the solidifying material G. Therefore, it is preferable to attach the buffer member 3.
The buffer member 3 is not limited to an O-ring, and may be an airtight tape made of butyl rubber, for example. The same effect can be obtained even with the cushioning member 3 formed by winding the airtight tape around the boundary portion between the anchor body 1 and the fixing body 2.

Further, as shown in FIG. 5, a step 2 b may be formed on the peripheral surface of the fixing body 2 in the post-construction anchor 10.
If the post-construction anchor 10 is formed with unevenness due to the step 2b on the peripheral surface of the fixing body 2, the frictional force between the fixing body 2 and the solidifying material G increases, so that the fixing power of the post-construction anchor 10 is improved. Can do. In addition, you may attach the buffer member 3 also to the construction anchor 10 after this.
For example, the fixing body 2 shown in FIG. 1B, the fixing body 2 shown in FIG. 1C, and the fixing body 2 shown in FIG. The fixing force of the post-construction anchor 10 can be adjusted.

Further, as shown in FIG. 6, a boundary portion between the anchor body 1 and the fixing body 2 in a state where the male thread 1 a of the anchor body 1 is formed by threading and the fixing body 2 is screwed to the anchor body 1. The construction anchor 10 may be used after forming a shape in which there is no step and each outer peripheral surface is continuous.
Since the outer diameter of the male screw 1a formed by threading can be made thinner than the diameter of the anchor main body 1, the outer periphery of the anchor main body 1 and the outer edge of the one end 21 of the fixing body 2 are made to coincide with each other. The construction anchor 10 can be formed after the respective outer peripheral surfaces are made continuous at the boundary with the fixing body 2.
If the construction anchor 10 is a post-construction anchor 10 in which each outer peripheral surface is continuous at the boundary between the anchor body 1 and the fixing body 2, for example, when a pulling force is applied to the construction anchor 10 after being installed on the concrete structure C, No load is applied to one end 21 of the fixing body 2.
With such a post-installed anchor 10, no load is applied to the one end 21 of the fixing body 2, and it is possible to prevent the fixing body 2 from being damaged. The fixing power of the construction anchor 10 is not reduced.

Further, as shown in FIG. 7A, the post-construction anchor 10 may be provided in which the other end 22 of the fixing body 2 is provided with a protruding portion 23 that narrows toward the opposite side of the anchor body 1.
The protrusion 23 of the present embodiment has a substantially conical shape. The protrusion 23 is not limited to a substantially conical shape, and may be any shape as long as it has a shape with a sharpened tip toward one point, such as a substantially pyramid shape.
In addition, you may attach the buffer member 3 also to the construction anchor 10 after this.

  A post-construction anchor construction method for installing the post-construction anchor 10 provided with the projection 23 at a predetermined location will be described.

First, as shown in FIG. 7B, an insertion hole H is formed at a predetermined location on the wall surface of the concrete structure C, and the solidification material G is filled in the insertion hole H. As the solidifying material G, for example, a grout material such as mortar or concrete can be used. In particular, in the case of the solidified material G having plasticity (thixotropic properties), the solidified material G filled in the insertion hole H is difficult to leak out, so that the subsequent steps are easy to perform.
Next, as shown in FIG. 7C, the post-construction anchor 10 is inserted into the insertion hole H from the protruding portion 23 side before the solidified material G is solidified. Since the tip of the projection 23 is pointed, the post-construction anchor 10 can be easily inserted into the insertion hole H filled with the solidifying material G.
Then, after the solidifying material G is solidified, a fixing plate (not shown) that closes the insertion hole H is fixed to the anchor body 1.

The post-construction anchor 10 can be installed on the existing concrete structure C by such a procedure, and the concrete structure can be reinforced by the post-construction anchor 10.
In particular, when the post-construction anchor 10 is inserted into the solidified material G from the protruding portion 23 side having a sharp tip, bubbles are less likely to enter the solidifying material G than when the fixing portion 2 is not provided with the protruding portion 23. ing.
On the other hand, when the construction anchor 10 (see FIG. 1A) after the projection 23 is not provided is inserted into the solidified material G, bubbles are formed in the solidified material G on the surface on the other end 22 side of the fixing body 2. May be pushed in. When the solidified material G is solidified in a state including bubbles unnecessary for design, the fixing force of the post-installed anchor 10 may not be obtained as designed, which is not preferable.
That is, when the post-construction anchor 10 is inserted into the insertion hole H filled with the solidifying material G and then the solidification material G is solidified and the post-construction anchor 10 is installed, the other end 22 side is set. If the fixing body 2 provided with the projection 23 is selected and attached to the anchor body 1 and the post-construction anchor 10 having the projection 23 is used, the fixing force of the post-construction anchor 10 is as designed. Can be stabilized.

  Even if the post-construction anchor 10 is provided with the protrusion 23, after the fixing body 2 side of the post-construction anchor 10 is inserted into the insertion hole H, the solidification material G is filled into the insertion hole H. You may install by the method.

  As described above, the post-construction anchor 10 according to the present embodiment can be replaced with the fixing body 2 having an appropriate shape according to the location where the post-construction anchor 10 is installed, so that the fixing force of the post-construction anchor 10 can be easily obtained. Can be adjusted.

  In the above embodiment, the anchor main body 1 and the fixing body 2 are made of steel. However, the present invention is not limited to this. For example, the anchor main body made of carbon or aramid Alternatively, a fixing member may be used. In this case, it is preferable to fix the anchor body and the fixing body by using a joining member such as a screw or an adhesive instead of screwing the anchor body and the fixing body.

Further, the male screw 1a may be formed on the iron or resin anchor body 1 that is not a PC steel rod by forging screw processing.
Moreover, you may form the external thread 1a in the anchor main body 1 which is a PC steel rod by threading.
That is, the material of the anchor body 1 is arbitrary, and the formation method of the male screw 1a may be any method.

In the above embodiment, the fixing body 2 has a truncated cone shape whose diameter increases from the one end 21 toward the other end 22. However, the present invention is not limited to this. For example, the fixing body 2 having a truncated pyramid shape, or a bell-shaped or bowl-shaped fixing body 2 may be used.
The fixing body 2 only needs to have a shape in which the cross-sectional area gradually increases from the one end 21 toward the other end 22, and an axially symmetric shape with the axis of the post-installed anchor 10 (anchor body 1) as the axis of symmetry. Alternatively, it may not be a line-symmetric shape with the axis as a symmetry line.

  In addition to the fixing body 2 described above, a multistage fixing body having a shape in which a plurality of fixing bodies 2 are connected may be used.

  In addition, it is needless to say that other specific detailed structures can be appropriately changed.

10 Post-installed anchor 1 Anchor body 1a Male screw 2 Fixing body 2a Screw hole 2b Step 21 One end 22 Other end 23 Projection 3 Buffer member C Concrete structure H Insertion hole G Solidified material P Support pressure

Claims (6)

A post-construction anchor comprising a rod-shaped anchor body and a fixing body that is replaceably attached to the tip of the anchor body,
At the tip of the anchor body which is a steel rod-shaped member, a male screw formed by forging screw processing is formed,
The fixing body is formed with a screw hole having a female screw that can be screwed with a male screw of the anchor body,
The post-construction anchor, wherein the fixing body has a shape in which a cross-sectional area gradually increases from one end to the other end, and the anchor main body is attached to the one end side. Before Symbol state where the fixing member to the anchor body is mounted, post-installed anchor according to claim 1, characterized in that the outer peripheral surface of each at the boundary portion between the anchor body and the fixing member are continuous . Post-installed anchor according to claim 1 or 2, characterized in that a cushioning member for covering the boundary portion between the fixing member and the anchor body. The post-construction anchor according to any one of claims 1 to 3 , wherein a step is formed on a peripheral surface of the fixing body. The post-construction anchor according to any one of claims 1 to 4 , wherein a protrusion that is narrowed toward the opposite side of the anchor body is provided at the other end of the fixing body. A post-construction anchor construction method for installing the post-construction anchor according to claim 5 at a predetermined location,
Forming an insertion hole at a predetermined location;
Filling the insertion hole with a solidifying material;
Inserting the post-construction anchor into the insertion hole from the protrusion side before the solidified material is solidified;
A post-installation anchor construction method characterized by comprising:

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