JP6647778B2 - Post-installed anchor and its installation method - Google Patents

Description

  The present invention relates to a post-installed anchor and a method of applying the post-installed anchor, which can secure the anchoring force even if a load is applied for a long period of time after the construction or the aged deterioration of the filling material occurs, after the construction. The present invention relates to a construction method for efficiently constructing a construction anchor.

  Conventionally, a post-installed anchor as shown in FIG. 5 (a) is known as a construction method for applying a post-installed anchor to existing concrete using an adhesive anchor. In the construction of this type of post-installed anchor, an anchor hole 52 having a diameter slightly larger than the diameter of the anchor bar 50 is drilled in the existing concrete 51 using a drilling device such as a hammer drill, and epoxy resin or cement containing capsules is drilled. A filler 53 serving as an adhesive material such as a grout is inserted into the anchor hole 52, the anchor bar 50 is built in the hole by rotation and impact, and the anchor bar 50 is integrally fixed to the concrete frame 51. As shown in FIG. 5A, the distal end 50a of the anchor streak 50 is cut at an angle of 45 degrees on one side, and is sharply finished. Thereby, the epoxy resin base material and the curing agent in the capsule previously inserted into the anchor hole are efficiently mixed, and the curing of the adhesive material is promoted.

  By the way, fillers such as epoxy resin and cement grout used as an adhesive material have high adhesion performance, but after long-term use, the epoxy resin and grout in the anchor hole shrink and become smooth. There is a problem that a gap is generated between the wall of the anchor hole and the filler, and the adhesion performance is reduced.

  In order to solve this problem, a plurality of grooves are formed along the depth direction on the inner peripheral surface of the anchor hole wall, and the filler is filled into these grooves, whereby the filler and the anchor hole wall are formed. (Non-Patent Document 1, FIG. 5 (b)) According to this method, the filler 53 is formed by the groove 55. By filling the inside, the adhesion area between the anchor hole wall 54 and the anchor hole wall 54 increases, so that a larger adhesion force is exhibited than in the case of the conventional smooth anchor hole wall 54. In addition, even if the filler 53 contracts after a long period of time after construction and a gap is formed between the anchor hole wall 54 and the filler 53, the gap between the filler 53 in the groove 55 and the anchor hole wall 54 can be reduced. Since there is mechanical locking, resistance to pull-out or the like is maintained.

  On the other hand, the transmission of stress between the anchor rebar and the filler is achieved by the adhesive force between the filler and the various concavo-convex patterns formed on the surface of the deformed reinforcing bar used as the anchor rebar. Since the rebar surface pattern is finer than the rebar diameter, the adhesive force per unit surface area is not so large. To provide the rebar with a specified anchoring force (pull-out strength), secure the specified anchoring length and secure the anchor. It must be buried in the hole.

  From the above, even when a plurality of grooves disclosed in Patent Document 1 are formed in the anchor hole wall, the adhesion strength between the reinforcing bar and the filler is equal to that of the conventional post-installed anchor, and the fixing length of the reinforcing bar is increased. The length is determined by the bonding strength between the reinforcing bar and the filler. For this reason, in order to secure the pull-out strength of the anchor, the anchoring length of the anchor streak cannot be shortened. As a solution to this, a method has been proposed in which a fixing plate is attached to the tip of an anchor bar (rebar) to increase the adhesive force between the reinforcing bar and the filler and improve the pullout resistance.

  For example, as an anchor structure for attaching a fixing plate to the tip of a reinforcing bar, an anchor bolt used for attaching a steel frame member such as a steel column base has been conventionally known. As this type of anchor bolt, an anchor structure is used in which a disk-shaped fixing plate is attached to the lower end of the bolt using a high-strength bolt, a male screw member, and a double tightening nut (Patent Document 1). These anchor bolts are mounted on a base previously set at a predetermined position in the formwork, and then concrete is cast, and a base plate of a pillar is set at the top of the concrete.

JP 2008-3149 A

Tanaka Dia Kogyo Co., Ltd., "Pull-out test of anchor bolts driven into holes with grooves", [online], June 28, 2013, Tanaka Dia Kogyo Co., Ltd. homepage, July 1, 2014 Search, Internet <URL: http://www.tanakadaiya.com/license/>

  Heretofore, there has been no example of designing a post-installed anchor in consideration of a long-term change in the filler, and there has been no method of solving the shortage of the adhesive force between the anchor streak and the filler by using a fixing plate. Further, in the construction work, an anchor bar with a fixing plate cannot be used for an anchor hole to be drilled by a post-installation anchor construction method. In addition, when a large number of anchor bars are to be constructed, if the work of the material for attaching the fixing plate to the tip of the anchor bars can be simplified, the construction period will be shortened. Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional technology, and to fix anchor bars to which a stress or a repetitive stress is applied for a long time with a fixing length shorter than that of a conventional post-installed anchor, on the skeleton side. An object of the present invention is to provide an anchor which can be made to work and an anchor construction method which can save labor compared to the conventional construction.

In order to achieve the above object, the post-installed anchor according to the present invention has a bump-like shape formed by pressing the tip into an anchor hole in which a peripheral surface groove is formed in a hole wall at a predetermined groove interval in a depth direction. anchors having a tip fixing portion bulges to integer form was formed which was of the said bottom of the hole of the anchor hole tip fixing portion is Tatekoma to be held upright, the circumferential surface groove of the anchor hole And a post-installed anchor characterized in that the anchor is held in the anchor hole with a filler filled so as to fill the periphery of the anchor streak, and forms a predetermined angle upward from an upper surface position of the distal end fixing portion. The gap between the grooves in the range up to the position where it intersects with the hole wall is smaller than the range from the range to the hole of the anchor hole so that the adhesive force between the hole wall and the filler near the tip fixing portion is reduced. It is characterized by having increased .

Further, it is preferable that the intermediate fixing portion is provided at an intermediate position in the length direction of the anchor streak.

Anchor streaks having a tip fixing portion formed by shaping a bulge formed by pressing a tip into an anchor hole in which a circumferential groove is formed in a hole wall at a predetermined groove interval in a depth direction, The anchor hole is erected at the bottom of the hole of the anchor hole so as to be held upright, and is filled with a filler filled so as to fill the inside of the peripheral surface groove of the anchor hole and the periphery of the anchor streak. a post installed anchors held in the groove spacing ranging to a position intersecting the hole wall at an angle theta = 45 to 60 ° upward from the upper surface position of the tip fixing portion, said from the scope It is characterized by being smaller than the range up to the hole of the anchor hole .

As an invention of a method for constructing a post-installed anchor, on the hole wall of the anchor hole, the interval between grooves formed in a predetermined depth direction from the hole bottom is made smaller than the range from the range to the hole of the anchor hole. the circumferential surface grooves are formed at intervals, the pressure processed anchors tip fixing portion is formed of a bulge formed were integer form by a tip, the tip fixing portion is erected held in bottom hole of the anchor hole In such a manner as to be built in the anchor hole, and to fill the inside of the peripheral groove of the anchor hole and the periphery of the anchor streak with a filler, thereby holding the anchor streak in the hole. .

It is preferable that the tip fixing portion of the post- installed anchor is supported upright at the bottom of the hole with the aid of an anchor support member.

  As described above, according to the present invention, it is possible to provide an anchor capable of securely anchoring an anchor bar to which a long-term stress or a repetitive stress acts on a skeleton side with a shorter anchoring length than a conventional post-installed anchor. It is also possible to save labor as compared with the conventional construction.

Explanatory drawing which showed the construction state of embodiment (fixed part shape) of the post-construction anchor of this invention. Explanatory drawing which showed other embodiment (change of groove space | interval) of the post-installed anchor of this invention. Explanatory drawing which showed the example of the fixing part formation method of the post-installed anchor of this invention. Explanatory drawing which showed the work procedure of the construction method of the post-construction anchor of this invention. Explanatory drawing which showed the example of a form of the conventional post-installed anchor.

Hereinafter, an embodiment of a post-installed anchor and a method of installing the same according to the present invention will be described with reference to the accompanying drawings. FIG. 1A shows a state in which the post-installation anchor according to the present invention is installed on an existing concrete skeleton 1.
An anchoring bar 10 shown in FIG. 1A has a fixing portion 11 formed at a lower end. The fixing portion 11 is formed by shaping a bulging portion formed by deforming an end of a reinforcing bar as described later. The end face of the fixing unit 11 is formed of a smooth cut surface. On the other hand, since the bottom surface 3 of the anchor hole 2 does not become a smooth surface when the drilling is completed, when the anchor streak 10 having the diameter d is erected on the bottom surface 3 of the anchor hole 2, as shown in FIG. It is preferable that the anchoring bars are erected through the filling and solidifying material as the support member 12 so as to be erected. The anchor support 12 may be a putty made of epoxy resin, an adhesive made of various resins, a solidifying material such as quick-setting mortar, or a metal or resin which can secure a predetermined height with respect to the bottom surface 3 as a mechanical support. Spacers or the like can be used. The outer shape of the fixing unit 11 is chamfered and shaped so as to have a circular cross section of a predetermined diameter (D1). When the anchor streaks 10 having the anchoring portions 11 are accommodated in the anchor holes, the anchor holes are formed so that the following relationship is provided between the anchoring portions 11 and the surrounding anchor hole walls 4. Is set (Dh).

The relationship between the thickness (diameter: d) of the anchor muscle 10 and the diameter (D1) of the anchoring section 11 is as follows.
D1 = (1.5-2.5) × d
The relationship between the diameter (D1) of the fixing portion 11 and the diameter (Dh) of the anchor hole is as follows.
Dh = D1 + Δ
At this time, as shown in FIG. 1A, the gap Δ can be reduced as long as the fixing portion 11 of the anchor streak 10 can be installed on the bottom surface 3 of the anchor hole.

  Further, a ring-shaped peripheral groove 5 is formed in the anchor hole wall 4 along the depth direction and is horizontal to the anchor hole wall 4. This peripheral groove 5 can be formed in the anchor hole wall 4 by the device described in Non-Patent Document 1 described above or another known groove forming device. When the peripheral groove 5 is a square groove as shown in the figure, the groove dimensions are as follows: groove depth Gd: about 2 to 5 mm, groove width Gw: about 9 to 20 mm, spacing p in the anchor depth direction: about 50 to 100 mm. Can be set to It is preferable that the specific groove size is appropriately designed and set according to the required anchoring force of the anchor bar 10. For example, the ratio between the depth and the height of the square groove at the time of design is preferably 1: 4 to 5 in order to maintain the adhesive force. Further, the groove cross-sectional shape can be a shape in which the hole wall 4 can be easily cut if a groove width which affects the shear strength of the filler 13 is ensured, for example, a substantially circular groove or a triangular groove. Can also.

  FIG. 1B shows an installation state of a post-installed anchor using an anchor bar 10 having a fixing portion 11 of a modified example attached to the tip. The fixing section 11 is formed by fixing a steel disk having a predetermined diameter (D2) to the tip of the anchor streak 10 by screwing. It is preferable to flatten the bottom surface of the fixing unit 11 using the flathead screw 15 for screwing. When a male screw is formed as the deformed pattern of the anchor muscle 10, a ring-shaped disc having a female screw that can be screwed to the male screw of the anchor muscle 10 can be used. In addition, a commercially available fixing plate for a reinforcing bar can also be used.

  FIG. 2A is an explanatory view showing a hole wall cross section of an embodiment of a construction anchor after changing a groove pitch formed in the hole wall 4 in consideration of a bearing effect in the fixing unit 11. When a pull-out force acts on the anchor bar 10, the fixing unit 11 exerts a large supporting force on the filler 13. It is preferable to increase the adhesive force over a predetermined range (range (a)) between the filler 13 and the anchor hole wall 4 to such an extent that the entire anchor can exhibit strength (proof strength) corresponding to the supporting pressure. The range (a) is set assuming the range of the bearing force of the fixing unit 11 when the pull-out force acts on the anchor muscle 10. Specifically, as shown in FIG. 2, the intervals between the peripheral grooves 5 located within a range that forms an angle θ (θ = 45 to 60 °) from the center position of the upper surface of the fixing unit 11 are made dense. As the balance of the entire groove interval, it is preferable that the groove interval in the range (a) be an interval p1 (p> p1) smaller than the groove interval p shown in FIG. In this case, since a sufficient anchor fixing effect can be obtained in the range (a) from the fixing unit 11, in the range (b) from the fixing range (a) to the anchor opening, the interval p2 can be set to p2> p.

  FIG. 2B is an explanatory view showing a hole wall cross section of an embodiment of a post-installed anchor using an anchor bar 10 provided with an intermediate fixing portion 14 in addition to the fixing portion 11 at the anchor tip. In the case of a post-installed anchor in which the anchor attachment length is designed to be large, an intermediate fixing section 14 can be provided in addition to the tip fixing section 11. After this, in the construction anchor, in addition to the design in which the groove interval is narrow (groove interval: p1) in the range (a) from the tip fixing portion 11, the groove is also formed in the range (a) from the position of the intermediate fixing portion 14 toward the anchor mouth. The interval can be set narrow (groove interval: p1), and the other range (b) can be set as the groove interval p2.

  FIG. 3 is an explanatory view showing a procedure in which a bulging portion 7b is formed on an end surface 7a at the tip of the reinforcing bar 7, and the bulging portion 7b is shaped to form an anchor bar 10 having a fixing portion 11. The manufacturing procedure of the anchor bar 10 will be briefly described with reference to the drawings. Two rebars 7 (deformed steel bars) serving as anchor bars 10 are held by a clamp (not shown) so as to be coaxial and straight (FIG. 3A). At this time, a release agent is applied to the end face 7a of the reinforcing bar that contacts. Thereafter, when the end of the contacted reinforcing bar 7 is pressed and pressed to heat the pressed portion to a red-hot state, as shown in FIG. 3 (b), a bump-like shape symmetrical with respect to the pressed boundary surface is obtained. A bulging portion 7b is formed. Thereafter, the two bulging portions 7b in the pressed state are integrally shaped by a rotary cutting device (not shown) (FIG. 3C), and a fixing portion 11 having a predetermined shape is formed at the end of the reinforcing bar 7. . By separating the two anchor streaks 10 at the peeling surface 7c, two anchor streaks 10 having substantially the same truncated cone-shaped fixing portion 11 at each end can be obtained (FIG. 3 (d)). )).

  FIG. 4 is an explanatory view showing a procedure for installing a post-installed anchor according to the present invention. Unlike the conventional post-installed anchor, the post-installed anchor of the present invention is different from the conventional post-installed anchor in that the anchor rebar is pre-built and stably held in the anchor hole, and then the filler is filled and solidified in the hole to form the anchor rebar. It is characterized by being fixed inside. First, as shown in FIG. 4A, a predetermined position of the existing concrete 1 is drilled, and the anchor hole 2 is provided with a diameter slightly larger than the diameter of the anchoring portion 11 of the anchor bar 10 to be built. Next, a plurality of grooves 5 are formed on the inner peripheral surface of the hole by using an inner groove drilling device. The dimensions of the groove 5 and the interval in the depth direction are designed within the range shown in FIG. 1A according to the standard of the anchor bar 10 to be used. When the formation of the peripheral groove 5 is completed, concrete pieces and dust collected on the bottom surface 3 are removed with compressed air, water, etc., and cleaned again. In the present embodiment, a ring-shaped steel spacer 16 is installed on the bottom surface 3 of the anchor hole 2 as an embodiment as an anchor support member for erecting the fixing portion 11, and the anchor bar 10 is erect thereon. (FIG. 4B). As a result, the anchor streaks 10 inserted into the anchor holes 2 become self-supporting because the anchor fixing portions 11 are placed on the steel spacers 16 installed on the bottom surface 3. It is also preferable to attach a spacer 17 to the mouth of the anchor hole 2 in order to raise the anchor bar 10 at the center of the cross section of the anchor hole (FIG. 4C). Thereafter, a cement grout material as a filler 13 is filled around the anchor bar 10 of the anchor hole 2. In order to fill the grout material, a grout material filling hose is inserted into the anchor hole, and the grout material is filled into the anchor hole 2 while pulling out the hose. The filler 13 may be a chemical-based material containing an epoxy acrylate resin or an epoxy resin as a main component in addition to the cement-based material. By leaving a predetermined curing period, it can be used as a post-installed anchor having a predetermined pull-out strength.

  It should be noted that the present invention is not limited to the above-described embodiment, and various changes can be made within the scope shown in each claim. That is, embodiments obtained by combining technical means appropriately changed within the scope of the claims are also included in the technical scope of the present invention.

Reference Signs List 1 Existing concrete 2 Anchor hole 4 Anchor hole wall 5 Peripheral groove 10 Anchor streak 11 Anchoring part (tip anchoring part)
12 anchor support 13 filler 14 intermediate fixing section

Claims (5)

Anchor with the anchor hole the peripheral surface groove formed in the bore wall with a predetermined groove spacing in the depth direction, a pressure processed distal fixing portion a knobby bulges formed is formed by integer form by a tip A streak is erected at the bottom of the hole of the anchor hole so that the tip fixing portion is held upright, and is filled with a filler filled to fill the inside of the peripheral groove of the anchor hole and around the anchor streaks. A post-installed anchor characterized by being held in the anchor hole ,
The gap between the grooves in a range from the upper surface position of the tip fixing section to a position intersecting the hole wall at a predetermined angle is smaller than the range from the range to the hole of the anchor hole, and the tip fixing section is A post-installed anchor , wherein the adhesive strength between the hole wall and the filler in the vicinity is increased . Anchor streaks having a tip fixing portion formed by shaping a bulge formed by pressing a tip into an anchor hole in which a circumferential groove is formed in a hole wall at a predetermined groove interval in a depth direction, The anchor hole is erected at the bottom of the hole of the anchor hole so as to be held upright, and is filled with a filler filled so as to fill the inside of the peripheral surface groove of the anchor hole and the periphery of the anchor streak. Construction anchor after being held in
The groove interval in a range from the upper surface position of the tip fixing portion to a position intersecting with the hole wall at an angle θ = 45 to 60 ° is smaller than a range from the range to the hole of the anchor hole. Characterized by post-installation anchor. The post-installed anchor according to claim 1 or 2 , wherein an intermediate fixing portion is provided at an intermediate position in a length direction of the anchor streak. 3. The post-installed anchor according to claim 1, wherein the distal end fixing portion is supported upright at the bottom of the hole with the aid of an anchor support member. 4. On the hole wall of the anchor hole, a circumferential groove is formed at an interval that is smaller than the range from the range to the hole of the anchor hole at intervals between grooves formed in a predetermined depth direction from the bottom of the hole. like an anchor to a pressure processed anchors tip fixing portion is formed to have integer form a bulge which is formed in the anchor downhole so that the distal end fixing portion is erected held in bottom hole of the anchor hole And filling the inside of the peripheral groove of the anchor hole and the periphery of the anchor streak with a filler, and holding the anchor streak in the hole, wherein the anchor is a post-installed anchor.

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