JP6174415B2 - Post-construction anchor and its construction method - Google Patents

Description

  The present invention relates to a post-construction anchor for reinforcing or expanding an existing concrete structure, and a construction method thereof.

  Conventionally, as a technology in such a field, there is Japanese Patent No. 3636632. The post-construction anchor described in this publication is provided with a threaded rod that forms the anchor body, a tapered nut and a locking nut that are screwed onto the end of the threaded rod, and an extension piece that is movable along the threaded rod. And an expanded metal fitting. A threaded rod with a set nut and a tapered nut screwed into the tip is inserted into an anchor hole drilled in an existing concrete structure. Then, the diameter-expanded metal fitting is dropped onto the tapered nut along the screw rod. In this dropping operation, the expanding metal fitting is driven so as to fit onto the tapered nut directly or via a sleeve with a driving rod as a jig. At this time, the expanded metal fitting is pressed downward by the jig, the plurality of expansion pieces move onto the tapered portion of the tapered nut, and each expanded piece of the expanded metal fitting expands along the tapered portion of the nut, It is press-fitted into the enlarged diameter portion of the anchor hole. Thereby, the screw rod is fixed in the anchor hole by the expansion force of the expansion piece. Thereafter, a grout made of resin or mortar is injected into the gap between the screw rod and the existing concrete structure, thereby fixing the screw rod to the anchor hole. Furthermore, corrosion of the threaded rod can be prevented by injecting grout.

Japanese Patent No. 3636632

  However, in the conventional post-construction anchor described above, a special driving rod or driving work is required for dropping the expanded metal fitting onto the tapered nut along the screw rod, so that the construction of the post-installing anchor is complicated. Therefore, since a special driving rod is also required, there is a problem that the workability of the post-construction anchor is poor. In addition, the diameter of the anchor hole to be drilled must be increased due to the use of a driving rod in the construction, but as the diameter of the anchor hole increases, the time required for drilling increases. This also causes deterioration of workability.

  It is an object of the present invention to provide a post-construction anchor having good workability and a construction method thereof.

The present invention is a post-construction anchor having a rod-like threaded anchor body embedded in an anchor hole formed in an existing concrete structure,
It is set in a substantially frustoconical space with an undercut formed on the bottom side of the anchor hole, has an insertion hole for inserting the anchor body, and faces the first inclined surface of the space with an undercut. A piece member having a second inclined surface;
While being fixed to the anchor body, the gap between the first inclined surface of the space portion with the undercut and the second inclined surface of the piece member is filled while the anchor body is pushed into the insertion hole of the piece member. An expansion member having an expansion piece to be entered,
The piece member is provided with a catching means for catching the expansion piece, and the piece member is formed with a discharge portion that communicates with the insertion hole and is located on the bottom side of the piece member .

  In the post-installation anchor, the piece of the post-construction anchor is inserted into the anchor hole of the existing concrete structure, and the anchor body is inserted into the hole of the piece member with the bottom face of the piece member installed on the bottom face of the anchor hole. When pushed in, the anchor body and the expansion member move downward together with the piece member. And the expansion piece of an expansion member approachs so that the clearance gap formed between the 1st inclined surface of the space part with an undercut and the 2nd inclined surface of a piece member may be filled up. As described above, when the expansion piece is sandwiched between the first inclined surface and the second inclined surface by the entry of the expansion piece into the gap, and the entry of the expansion piece into the gap is completed, the expansion piece is moved into the piece member by the catching means. As a result, the expansion member and the anchor body are firmly fixed in the anchor hole. Therefore, the anchor main body is prevented from coming off. Moreover, when a pulling load is applied to the anchor main body, the expansion piece is sandwiched between the first inclined surface and the second inclined surface, and the expansion piece is caught by the piece member by the catching means. The load can be firmly received by the first inclined surface of the space portion with the undercut of the anchor hole, and the wall surface of the anchor hole is less likely to be distorted or cracked. Furthermore, since such post-installed anchors do not require special tools such as a driving rod, the workability is good, and the diameter of the anchor hole needs to be increased in consideration of the diameter of the driving rod. Therefore, the time required for drilling can be shortened.

In addition, the hooking means is provided on one or a plurality of first uneven portions formed on the second inclined surface and an inner wall surface of the extended piece that faces the second inclined surface when the extended piece enters the gap. One or a plurality of second concavo-convex portions that are formed and fit with the first concavo-convex portions.
As described above, when the catching means is constituted by the first uneven portion formed on the second inclined surface and the second uneven portion formed on the inner wall surface of the extension piece, the anchor main body portion is inserted into the insertion hole. When the expansion piece is inserted into the gap, the second uneven portion of the expansion piece is fitted into the first uneven portion of the piece member. Therefore, when a pulling load is applied to the anchor main body, the second uneven portion of the expansion piece is caught on the first uneven portion of the piece member. Therefore, it is possible to prevent the anchor main body from coming off simply by forming the uneven portion on the second inclined surface of the piece member and the inner wall surface of the extension piece.

Further, the catching means is constituted by a claw portion that protrudes inward from the lower end of the extension piece, and a chamfered portion that is formed at the lower end of the truncated cone-shaped piece member and abuts the claw portion.
When such a configuration is adopted, when the anchor body portion is pushed into the insertion hole and the expansion piece is inserted into the gap, the claw portion protruding inward from the lower end of the expansion piece extends along the second inclined surface of the piece member. Move down. And if a nail | claw part moves downward to the lower end of a piece member, it will enter into the chamfering part of a piece member from the outer side, will contact | abut to a chamfering part, and will be fitted. Therefore, when a pulling load is applied to the anchor main body portion, the claw portion is caught at the lower end of the piece member, so that the anchor main body portion can be prevented from coming off with a simple structure such as a claw portion or a chamfered portion. .

In addition , since the grout filled in the insertion hole of the piece member can be discharged to the outside through this discharge portion, the grout is fixed to the anchor hole before inserting the post-installed anchor into the anchor hole of the existing concrete structure. It can be filled inside. Thus, by pre-filling the anchor hole with grout, it is possible to reliably fill the grout around the construction anchor in the anchor hole. This makes it difficult to corrode post-installed anchors, and makes it easier for the grout to contribute to improving the pullout strength of the anchor body.

Further, a third inclined surface that is temporarily fixed to the second inclined surface of the piece member is formed at the tip of the expansion piece of the expansion member before the anchor body is pushed into the insertion hole of the piece member.
When such a configuration is adopted, when the anchor body is pushed into the insertion hole of the piece member, the tip of the expansion piece of the expansion member is connected to the first inclined surface of the space portion with the undercut and the second inclination of the piece member. It has an effect that it is easy to smoothly enter the gap between the surfaces. As a result, an excessive load is not applied to the expansion piece.

The present invention is a post-construction anchor construction method in which a rod-shaped threaded anchor body is embedded in an anchor hole formed in an existing concrete structure.
1st process of forming the anchor hole which consists of a column-shaped anchor hole main body formed in the existing concrete structure, and the space part with an undercut of the substantially truncated cone shape connected to the edge part of an anchor hole main body with a drill When,
A second step of inserting the construction anchor into the anchor hole after the expansion member is fixed in the middle of the anchor body and the piece member is temporarily fixed to the tip of the expansion member;
A third step of grounding the piece member to the bottom surface of the anchor hole;
The anchor body is pushed into the insertion hole of the piece member, and the extension piece provided on the extension member is formed on the first inclined surface formed on the wall surface of the space part with the undercut and the second formed on the surface of the piece member. A fourth step of entering to fill a gap between the inclined surface of
A fifth step in which the expansion piece is hooked on the piece member by the hooking means ,
Before the second step, grout is filled into the insertion hole of the piece member,
As the grout is pushed into the insertion hole of the piece member, the grout is discharged from the discharge portion formed in the piece member into the space portion with the undercut .

  Thereafter, in the construction method of the construction anchor, by performing the first to fifth steps, the extension piece is between the first inclined surface of the space portion with the undercut and the second inclined surface of the piece member. In order to fill the gap formed in the first and second inclined surfaces, the first inclined surface and the second inclined surface are sandwiched. When the extension piece enters the gap, the extension piece is caught by the piece member by the catching means, so that the extension member and the anchor main body are firmly fixed in the anchor hole, and the anchor main body portion is prevented from coming off. The Moreover, when a pulling load is applied to the anchor main body, the expansion piece is sandwiched between the first inclined surface and the second inclined surface, and the expansion piece is caught by the piece member by the catching means. The load can be firmly received by the first inclined surface of the space portion with the undercut of the anchor hole, and the wall surface of the anchor hole is less likely to be distorted or cracked. Furthermore, since such post-installed anchors do not require special tools such as a driving rod, the workability is good, and the diameter of the anchor hole needs to be increased in consideration of the diameter of the driving rod. Therefore, the time required for drilling can be shortened.

In addition , since the grout filled in the insertion hole of the piece member can be discharged to the outside through the discharge portion, the grout is inserted into the anchor hole before inserting the post-installed anchor into the anchor hole of the existing concrete. Can be filled. Thus, by pre-filling the anchor hole with grout, it is possible to reliably fill the grout around the construction anchor in the anchor hole. This makes it difficult to corrode post-installed anchors, and makes it easier for the grout to contribute to improving the pull-out strength of the anchor main body.

  The post-construction anchor and its construction method according to the present invention have an excellent effect that the workability is very good.

It is sectional drawing which shows one Embodiment of the post-construction anchor which concerns on this invention. It is a perspective view which shows the expansion member applied to the construction anchor shown in FIG. It is a perspective view which shows a piece member. It is a cross-sectional view of the piece member shown in FIG. It is sectional drawing which shows the state after the completion of construction of the post-construction anchor shown by FIG. It is sectional drawing which shows the state which drilled the anchor hole to the existing concrete structure. It is sectional drawing which shows the other example of a piece member and an expansion member. It is sectional drawing which shows the further another example of a piece member and an expansion member.

  Hereinafter, preferred embodiments of a post-construction anchor and a construction method thereof according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the post-installed anchor 1 is configured such that a bolt 3 that forms an anchor body is implanted in an anchor hole S formed by a drill in an existing concrete structure 2, and the bolt 3 is attached to the existing concrete structure 2. It is constructed so as to be exposed from the surface. The anchor hole S in which the bolt 3 is implanted communicates with the columnar anchor hole main body S1 and the end of the anchor hole main body S1 by drilling, and is substantially formed on the bottom side of the anchor hole S. A frustoconical space portion S2 with an undercut.

  The post-construction anchor 1 has a rod-like bolt (threaded anchor body) 3 embedded in the anchor hole S and an insertion hole 10a into which the bolt 3 is inserted while being set in the space part S2 with an undercut. The piece member 10 having the second inclined surface P2 facing the first inclined surface P1 of the space portion S2 with the undercut and the bolt 3 is fixed to the bolt 3, and the bolt 3 is pushed into the insertion hole 10a of the piece member 10. On the other hand, the expansion member 20 includes the expansion piece 22 that enters the gap R between the first inclined surface P1 of the space portion S2 with the undercut and the second inclined surface P2 of the piece member 10 to fill the gap R. Has been.

  As shown in FIGS. 1 and 2, the expansion member 20 made of metal (for example, steel) has a central through hole 20 a with a female thread that can be screwed to the bolt 3 and extends in the direction of the axis L. The expansion member 20 includes a cylindrical head 21, an expansion piece 22 extending in the direction of the axis L of the bolt 3 on the end side of the head 21, and a periphery between the head 21 and the expansion piece 22. And a thin bent portion 23 created by forming a concave portion 23a in the direction. The head portion 21 and the expansion piece 22 of the expansion member 20 are connected via a thin bent portion 23.

  The extension pieces 22 form a hanging piece from the head 21 and are arranged in a plurality (for example, four) at regular intervals in the circumferential direction of the head 21. Each extension piece 22 is formed as a rectangular parallelepiped plate piece, the inner wall surface of the extension piece 22 is separated from the bolt 3, and the outer wall surface of the extension piece 22 coincides with the outer peripheral surface of the head 21 in the axis L direction. ing. The inner wall surface of the extension piece 22 is a surface that faces the second inclined surface P2 when the extension piece 22 enters the gap R, and the inner wall surface of the extension piece 22 has triangular wave-like irregularities continuous in the direction of the axis L. A portion (second uneven portion) 22a is formed. Further, a third inclined surface P3 that is temporarily fixed to the second inclined surface P2 of the piece member 10 before the bolt 3 is pushed into the insertion hole 10a of the piece member 10 is formed at the tip of the extension piece 22. ing.

  By adopting the third inclined surface P3, when the bolt 3 is pushed into the insertion hole 10a of the piece member 10, the tip of the expansion piece 22 of the expansion member 20 is connected to the first inclined surface P1 of the space portion S2 with an undercut. And the second inclined surface P2 of the piece member 10 have an effect that it is easy to smoothly enter the gap R. Thereby, an excessive load is not applied to the extension piece 22, and the extension piece 22 can be arranged at a predetermined position without being separated from the head 21.

  In addition, a screw insertion hole 24 for fixing the expansion member 20 at a predetermined position of the bolt 3 is formed in the head portion 21. The expansion member 20 is fixed at a predetermined position of the bolt 3 by screwing the screw 25 from the screw insertion hole 24 toward the bolt 3 and crimping the tip of the screw 25 to the bolt 3. The diameter of the expansion member 20, that is, the diameter of the head portion 21, is formed to be slightly smaller than the diameter of the columnar anchor hole body S1, and thus the expansion member 20 can be moved along the anchor hole body S1.

  As shown in FIGS. 1, 3, and 4, the piece member 10 having the insertion hole 10 a extending in the direction of the axis L includes a cylindrical seating portion 10 </ b> A placed on the bottom surface Sa of the anchor hole S, The cone-shaped reduced diameter portion 10B having a second inclined surface P2 extending from the end portion of the seating portion 10A in the axis L direction. Thus, the piece member 10 has a simple structure constituted by the cylindrical seating portion 10A and the truncated cone-shaped reduced diameter portion 10B, and has a shape that is easy to manufacture.

  Further, the inclined surface P2 located on the front side of the reduced diameter portion 10B is formed with a triangular wave-shaped uneven portion (first uneven portion) 10d, and when the expansion piece 22 enters the gap R, the reduced diameter portion When the concavo-convex portion 22a formed on the inner wall surface of the extension piece 22 is engaged with the concavo-convex portion 10d of 10B, the extension piece 22 is caught by the piece member 10 (see FIG. 5). That is, the catching means 70 for catching the expansion piece 22 on the piece member 10 is configured by the unevenness portion 10 d of the piece member 10 and the unevenness portion 22 a of the extension piece 22.

  The seat portion 10A of the piece member 10 is formed with a discharge portion 10b that communicates with the insertion hole 10a and is located on the bottom side of the seat portion 10A of the piece member 10. Each discharge portion 10b has a groove shape in which the bottom surface 10c of the seating portion 10A is cut out in a U shape in the axis L direction, and is formed at equal intervals with a phase angle of 90 degrees. By adopting such a configuration, the grout G (see FIG. 1) filled in the insertion hole 10a of the piece member 10 can be discharged to the outside through the discharge portion 10b. Before being inserted into the anchor hole S of the concrete structure 2, the grout G can be filled into the anchor hole S (see FIG. 6).

  In this way, by pre-filling the anchor hole S with the grout G, it is possible to reliably fill the grout G around the construction anchor 1 in the anchor hole S. Accumulation is unlikely to occur, thereby making it difficult for the construction anchor 1 to corrode later and making the grout G contribute to the improvement of the pull-out strength of the bolt 3. Further, as the grout G, a high-viscosity plastic grout, which is a cement grout material, is used, so that the grout G can be filled in the insertion hole 10a of the piece member 10 in advance. The grout G in the insertion hole 10a is discharged to the outside through the discharge portion 10b.

  As shown in FIG. 1, in the post-construction anchor 1 described above, first, the expansion member 20 is fixed with screws 25 in the middle of the bolt 3, and the third inclination located at the tip of the expansion piece 22 in the expansion member 20. The second inclined surface P2 of the piece member 10 is lightly temporarily fixed to the surface P3 with an adhesive (see the two-dot chain line). In such an assembled state, the post-construction anchor 1 is inserted into the anchor hole S of the existing concrete structure 2. Then, the bottom surface 10 c of the piece member 10 is installed on the bottom surface Sa of the anchor hole S.

  As shown in FIG. 5, in this state, the bolt 3 is pushed into the insertion hole 10 a of the piece member 10 by hitting the upper portion 3 b of the bolt 3 with a hammer H from above. At this time, the bolt 3 and the expansion member 20 move downward together with the piece member 10. Then, after the temporary fixing of the third inclined surface P3 to the second inclined surface P2 of the piece member 10 is released by hitting the hammer H, the extension piece 22 is bent under the thin bent portion 23 while being It enters so that the clearance gap R between the 1st inclined surface P1 of the space part S2 with a cut and the 2nd inclined surface P2 of the piece member 10 may be filled.

  As the expansion piece 22 enters the gap R, the end surface of the bolt 3 becomes substantially the same as the bottom surface 10c of the piece member 10, and the expansion piece 22 is sandwiched between the first inclined surface P1 and the second inclined surface P2. Thus, the entry of the extension piece 22 into the gap R is completed. At this time, the uneven portion 22a formed on the inner wall surface of the expansion piece 22 meshes with the uneven portion 10d formed on the inclined surface P2 of the piece member 10, and the expansion piece 22 is caught by the piece member 10, so that the expansion member 20 and The bolt 3 is firmly fixed in the anchor hole S, and the bolt 3 is prevented from coming off.

  Moreover, when a pulling load is applied to the bolt 3, the extension piece 22 is sandwiched between the first inclined surface P 1 and the second inclined surface P 2, and the extension piece 22 is caught by the catching means 70. Since it is caught by the member 10, the load can be firmly received by the first inclined surface P1 of the space portion S2 with the undercut, and the wall surface of the anchor hole S is unlikely to be distorted or cracked. Furthermore, since such post-installed anchors do not require a jig such as a special driving rod, the workability is good and the diameter of the anchor hole S needs to be increased in consideration of the diameter of the driving rod. Therefore, the time required for drilling can be shortened.

  Next, the construction method of the post-construction anchor 1 will be briefly described.

  As shown in FIG. 6A, a columnar anchor hole body S1 is formed in the existing concrete structure 2 by a normal drilling process. Next, as shown in FIG. 6B, an undercut portion U is formed at the end of the anchor hole body S1 by drilling. For the formation of the undercut portion U, a special rotary tool called an under cutter is used. By such drilling, the anchor hole S has an existing concrete structure so that it has a columnar anchor hole body S1 and a space part S2 with an undercut in a substantially truncated cone shape communicating with the anchor hole body S1. 2 is formed.

  After forming the anchor hole S with a drill, about 80% of the grout G is injected into the anchor hole S into the entire space in the anchor hole S. Further, as shown in FIG. 1, the grout G is filled in the insertion hole 10 a of the piece member 10 from below. Thereafter, the post-construction anchor 1 is inserted into the anchor hole S. As shown in FIGS. 1 and 5, the grout G filled in the insertion hole 10a of the piece member 10 is struck with a hammer H from above and the bolt 3 is pushed into the insertion hole 10a. Then, it is discharged from the discharge portion 10b formed in the piece member 10 into the space portion S2 with an undercut.

  Further, when the bolt 3 is struck with the hammer H, the extended piece 22 enters the thin bent portion 23 so as to fill the gap R while spreading outward, and the uneven portion 22a of the extended piece 22 enters the uneven portion 10d of the piece member 10. The engagement of the extension piece 22 into the gap R is completed in a state where the extension piece 22 is caught by the piece member 10. At this time, the grout G reaches the surface of the existing concrete structure 2 or slightly overflows from the surface of the existing concrete structure 2.

  The present invention is not limited to the above-described embodiment, and various modifications as described below are possible without departing from the gist of the present invention.

  In the above embodiment, the piece member 10 is constituted by the cylindrical seating portion 10A and the truncated cone-shaped reduced diameter portion 10B, but the shape of the piece member can be changed as appropriate. For example, as shown in FIG. 7, it is possible to use a piece member 30 having a truncated cone-shaped reduced diameter portion 30A.

  Moreover, in the said embodiment, although the catching means 70 was comprised by the triangular-wave-shaped uneven | corrugated | grooved part 10d and 22a, the shape of a catching means can be changed suitably. For example, the hooking means may be constituted by sawtooth-shaped uneven portions, and in this case, the extension piece can be effectively hooked by the piece member.

  Further, one convex portion 31 that protrudes from the inclined surface P4 of the piece member 30 in a right triangle shape and extends in the circumferential direction of the piece member 30, and a right triangle shaped concave portion 41 formed on the inner wall surface of the extension piece 42, It is also possible to constitute the catching means 80. In the piece member 30 and the expansion member 40, the tip 42a of the expansion piece 42 is positioned above the convex portion 31 before the bolt 3 is struck with the hammer H. The tip 42a of 42 moves downward along the inclined surface P4 and reaches the inclined surface 31a of the convex portion 31. Then, after the tip 42 a of the extension piece 42 further moves downward and gets over the convex portion 31, the extension piece 42 is hooked on the piece member 30 by being fitted into the lower portion of the convex portion 31.

  Further, as shown by the piece member 50 and the expansion member 60 in FIG. 8, the claw portion 61 projecting inwardly at the lower end of the expansion piece 62 of the expansion member 60 and the lower end of the truncated cone-shaped piece member 50 are chamfered. The catching means 90 may be constituted by the chamfered portion 51 formed in this way. The chamfered portion 51 of the piece member 50 is reduced in diameter as it goes downward. In the piece member 50 and the expansion member 60, the tip 61a of the claw portion 61 is positioned on the inclined surface P5 of the piece member 50 before the bolt 3 is struck with the hammer H, and when the bolt 3 is struck with the hammer H, The claw portion 61 moves downward along the inclined surface P5, and then the claw portion 61 comes into contact with the chamfered portion 51 from the outside, and thereby the expansion piece 62 is caught on the piece member 50.

  Moreover, in the said embodiment, although the 2nd inclined surface P2 of the piece member 10 was temporarily fixed to the 3rd inclined surface P3 of the expansion piece 22 with the adhesive agent, the method of temporarily fixing is not limited above. That is, instead of the adhesive, it may be temporarily fixed by engagement of unevenness or spot welding.

  In the above embodiment, the expansion member 20 is fixed to the bolt 3 with the screw 25, but the means for fixing the expansion member 20 to the bolt 3 is not limited to the screw 25. For example, it is possible to fix the expansion member 20 to the bolt 3 with a nut screwed to the bolt 3 at the top of the expansion member 20, and in this case, the screw insertion hole 24 and the screw 25 can be omitted.

  Further, in the above embodiment, the grout G is filled in the insertion hole 10a before the construction anchor 1 is inserted into the anchor hole S. However, the grout G may not be filled in the insertion hole 10a in advance. . That is, if the grout G is filled in at least the anchor hole S before the post-construction anchor 1 is inserted into the anchor hole S, the grout G is reliably filled around the post-construction anchor 1 in the state after the construction. Sometimes it is.

  Moreover, in the said embodiment, although the expansion member 20 was comprised with the metal, it is also possible to use ceramics, resin, etc. as a material of an expansion member.

  In the above embodiment, each discharge portion 10b of the piece member 10 has a U shape and is arranged at equal intervals with a phase angle of 90 degrees. However, the shape and arrangement of each discharge portion can be changed as appropriate. It is.

  Moreover, in the said embodiment, as FIG.1 and FIG.5 shows, the anchor hole S extended to the perpendicular direction, and the post-construction anchor 1 was inserted from the top, but the post-construction anchor 1 is inserted from the side or the bottom. The mode to insert may be sufficient and the direction which inserts the post-construction anchor 1 is not specifically limited. In addition, even when the post-construction anchor 1 is inserted into the anchor hole from the bottom, it is possible to fill the anchor hole with the grout G in advance, but in order to avoid a situation where the grout G droops from the anchor hole due to vibration or the like, When the post-construction anchor 1 is constructed, the anchor hole is preferably sealed with a lid-like member.

  Although the anchor main body has been described by taking a bolt as an example, the anchor main body can be applied even if a screw is cut at the tip of a threaded reinforcing bar or a deformed reinforcing bar. In this deformed reinforcing bar, by appropriately adjusting the length of the threaded portion, when the central through hole 20a extending in the axis L direction in the expansion member 20 is screwed in from the lower end of the threaded portion of the deformed reinforcing bar, the screw is It becomes impossible to rotate with the rod-shaped part which is not cut, and the expansion member 20 can be firmly fixed at the position. In this case, a screw 25 and a nut for fixing the expansion member 20 to the bolt 3 are not necessary.

DESCRIPTION OF SYMBOLS 1 ... Post-construction anchor, 2 ... Existing concrete structure, 3 ... Bolt (anchor main body), 10 ... Piece member, 10A ... Seating part, 10B ... Reduced diameter part, 10a ... Insertion hole, 10b ... Discharge part, 10c ... Bottom DESCRIPTION OF SYMBOLS 10d ... Uneven part (1st uneven part), 20 ... Expansion member, 20a ... Central through-hole, 22 ... Expansion piece, 22a ... Uneven part (2nd uneven part), 23 ... Bending part, 30 ... Piece member , 30A ... reduced diameter part, 31 ... convex part, 40 ... expansion member, 41 ... concave part, 42 ... expansion piece, 50 ... piece member, 51 ... chamfering part, 60 ... expansion member, 61 ... claw part, 62 ... expansion piece , 70, 80, 90 ... catching means, G ... grout, L ... axis, P1 ... first inclined surface, P2 ... second inclined surface, P3 ... third inclined surface, R ... gap, S ... anchor hole , S1 ... anchor hole main body, S2 ... space with undercut, Sa ... bottom surface U ... undercut portion.

Claims (5)

In post-construction anchors having rod-shaped threaded anchor bodies embedded in anchor holes formed in existing concrete structures,
A first inclined surface of the undercut space portion having an insertion hole into which the anchor body is inserted and set in a substantially frustoconical space portion with an undercut formed on the bottom side of the anchor hole. A piece member having a second inclined surface opposed to
While being fixed to the anchor body and pushing the anchor body into the insertion hole of the piece member, the first inclined surface of the space portion with the undercut and the second inclined surface of the piece member An expansion member having an expansion piece to enter so as to fill a gap between,
A hooking means for hooking the expansion piece to the piece member is provided ,
A post-construction anchor, wherein the piece member is formed with a discharge portion that communicates with the insertion hole and is positioned on the bottom side of the piece member .   The hooking means includes one or a plurality of first concavo-convex portions formed on the second inclined surface, and the extended piece that faces the second inclined surface when the extended piece enters the gap. 2. The post-construction anchor according to claim 1, wherein the post-construction anchor is formed by one or a plurality of second concavo-convex portions that are formed on the inner wall surface of the first concavo-convex portion and engage with the first concavo-convex portion.   The hooking means is constituted by a claw portion projecting inward from the lower end of the extension piece, and a chamfered portion formed at the lower end of the truncated cone-shaped piece member and in contact with the claw portion. The post-construction anchor according to claim 1, wherein A third inclined surface that is temporarily fixed to the second inclined surface of the piece member before the anchor main body is pushed into the insertion hole of the piece member is provided at the distal end of the expansion piece of the expansion member. The post-construction anchor according to any one of claims 1 to 3 , wherein the post-construction anchor is formed. In the post-installation anchor construction method, a rod-shaped anchor body with a screw is embedded in the anchor hole formed in the existing concrete structure.
A first anchor hole is formed by drilling, which includes a columnar anchor hole body formed in the existing concrete structure and a substantially frustoconical space with an undercut communicating with an end of the anchor hole body. And the process of
A second step of inserting the construction anchor into the anchor hole after the expansion member is fixed in the middle of the anchor body and the piece member is temporarily fixed to the distal end of the expansion member;
A third step of grounding the piece member to the bottom surface of the anchor hole;
The anchor body is pushed into the insertion hole of the piece member, and the extension piece provided on the extension member is placed on the first inclined surface formed on the wall surface of the space portion with the undercut and the surface of the piece member. A fourth step of entering to fill a gap between the formed second inclined surface;
A fifth step in which the expansion piece is hooked on the piece member by a hooking means;
Equipped with a,
Before the second step, grout is filled into the insertion hole of the piece member,
The post- construction anchor is characterized in that the grout is discharged from the discharge portion formed in the piece member into the space portion with the undercut as the anchor body is pushed into the insertion hole of the piece member. Construction method.

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