JP2001214534A - Anchor structure and its work execution method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anchor structure for use as both a form and a scaffold capable of being integrated into concrete with good workability without causing cracking of the concrete. SOLUTION: The anchor structure A comprises a metallic bar 1 with a thread 3 formed at its end, and a metallic cone member 4 connectable to the thread 3 on the metallic bar 1. The metallic cone member 4 is screwed in the thread 3 on the metallic bar 1, and the anchor structure A is embedded in concrete with the large-diameter-side end of the metallic cone member 4 exposed to the surface of the structure. The metallic cone member 4 is provided on its diameter side with a fastening member 5 for detachably fixing together a fastening member 10 for attaching to a concrete placement form and another fastening member for mounting a scaffold.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anchor structure and a method for constructing the same.

[0002]

2. Description of the Related Art When a structure such as a pier made of reinforced concrete is constructed, an anchor structure for attaching a formwork or a scaffold is used. Conventionally, the anchor structure
For example, as shown in FIG. 9, a metal tube c having an internal thread a formed inside and a spiral ridge b formed outside, and a plastic cap fitted to the outer end of the metal tube c It is composed of a member d and a bolt e or the like which is screwed into the female screw a, and the anchor structure f is attached to the curtain plate h of the formwork g by fastening the bolt e, and concrete k is cast inside. After the concrete k has hardened,
The bolt e was removed and the formwork g was removed.

[0003]

However, in the conventional anchor structure f described above, the cap member d is exposed to the outside after the mold g is removed.
The cap member d was easily deteriorated. When the cap member d is deteriorated, a gap is generated between the metal pipe c and the concrete k, and rainwater infiltrates the inside of the concrete k from the gap to corrode the metal pipe c and the reinforcing steel provided inside. This causes the destruction of the concrete k to progress relatively early. Further, if the metal pipe c is buried in the concrete k as it is without using such a cap member d, a crack may be generated from the surface due to a large difference in thermal expansion.

On the other hand, when the scaffold is assembled after the concrete k is cast, a high-strength anchor structure is required, but the anchor structure f for a formwork as described above.
Then, because of insufficient strength, it cannot be directly applied to scaffolds. Thus, the anchor structure f for the formwork
It is not preferable to increase the diameter of the bolt e so that a large bolt hole must be formed in the curtain plate h so that the bolt can be applied to a scaffold.

Accordingly, an object of the present invention is to provide an anchor structure that can be used as a formwork and a scaffold that can be integrated into concrete with good workability without causing cracks in the concrete.

[0006]

In order to achieve the above-mentioned object, an anchor structure according to the present invention comprises a metal rod having a thread formed at an end thereof, and a metal cone member screwed to the screw of the metal rod. An anchor structure embedded in concrete with the metal cone member being screwed into the screw of the metal rod to expose the large-diameter end surface of the metal cone member to the surface. On the large diameter side of the metal cone member, there is provided a fastening portion for detachably fixing a fastening member attached to the concrete casting formwork and a fastening member for attaching the scaffold.

[0007] The fastening portion of the metal cone member includes:
The large-diameter screw of a two-stage bolt integrally formed with a small-diameter screw for fixing the formwork and a large-diameter screw having the same diameter and the same pitch as the fastening member for fixing the scaffold is screwed together. Is preferably formed.

A concrete casting formwork and a scaffolding anchor structure comprising a metal rod having a thread formed at an end thereof and a metal cone member screwed to the screw of the metal rod are embedded in concrete. The large-diameter end face of the metal cone member is exposed to the surface, the screwing of the metal cone member to the metal rod is released, the metal cone member is removed, and a void formed by the metal cone member is removed. A filling member made of substantially the same material as that of the concrete is closed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing an embodiment.

FIG. 1 shows a cross section of a main part of an anchor structure A. In FIG. 1, reference numeral 1 denotes a metal rod, reference numerals 2 and 3 denote screws formed at both ends of the metal rod 1, and reference numeral 4 denotes a substantially conical shape. The formed metal cone member 5, 5 is a large-diameter female screw (fastening portion) formed inside the metal cone member 4, and 6 is a small-diameter female screw. A hexagonal hole (removal locking part) for removing the metal cone member 4 is provided on the radial end face).
7 are formed. Reference numeral 8 denotes a two-step bolt made of high-strength steel, and a small-diameter screw (fastening member) 10 for fixing to a formwork 9 (see FIG. 2) and a fastening bolt (fastening) for fixing a scaffold 11 (see FIG. 3). Large diameter screw with same diameter and same pitch as 12)
13 and are integrally formed. For example, it is preferable that the small diameter screw 10 is set to about M9 and the large diameter screw 13 is set to about M22.

A case where such an anchor structure A is applied to the construction of a pier 14 for supporting an expressway as shown in FIGS. 6 to 8 will be described.
Is divided into a plurality of blocks 141 having a predetermined height, and the scaffold 11
While sliding up
141 A method called “instrumenting insects” is used.

In such a construction method, first, a formwork 9 for forming the lowermost block body 141 at the ground level is assembled on the ground, filled with concrete 19 and hardened, and then the formwork 9 is removed. And a scaffold around the block body 141
11 is erected, the pipe scaffold 26 is assembled thereon, and the formwork 9 for forming the next block body 142 is assembled.

Next, the concrete 19 is filled in the form 9 and the next block 142 is formed on the block 141. When the next block body 142 is formed, the scaffold (not shown) 11 attached to the lower block body 141 is slid upward together with the pipe scaffold 26 by a crane or the like,
As shown in FIG. 7, it is assembled into the next block body 142 and reused. Thereafter, similarly, the scaffold 11 is slid together with the pipe scaffold 26 upward, and the blocks 143 are stacked and stacked.

In this construction method, first, as shown in FIG. 2, a nut 17 is fastened by inserting a small-diameter screw 10 into a perforation 16 formed at a predetermined position of a curtain plate 15 of a mold frame 9. By assembling the anchor structure A inside the curtain plate 15 to assemble the molds 9 into a predetermined shape (not shown),
After screwing the retaining member 18 into the screw 2 of the metal rod 1,
Concrete 19 is poured into the inside of the formwork 9. The retaining member 18 is formed by welding a nut to a plate member having an opening for screw insertion.

Next, after the concrete 19 has hardened, the nut 17 is removed, the formwork 9 is removed, and the two-step bolt 8 is also removed using a power tool (not shown). Then, as shown in FIG. 3, the scaffold 11 is carried into the wall surface of the concrete 19, and the bolt holes 20,
The scaffold 11 is fixed to the concrete 19 by inserting a large-diameter fastening bolt 12 through the screw 21 and screwing it into the large-diameter female screw 5 of the metal cone member 4. And scaffold
Assemble the pipe scaffold 26 on 11.

After the work on the scaffold 11 and the pipe scaffold 26 is completed, the fastening bolt 12 is removed, the scaffold 11 is removed, and the metal cone member 4 is formed on the large diameter side as shown in FIG. The hexagonal shaft member 23 mounted on the head 22 of the power tool is fitted into the hexagonal hole 7 and the metal cone member 4 is rotated in a direction in which the female screw 6 is disengaged from the screw 3 of the metal rod 1. The metal cone member 4 to concrete
Pull out from 19.

Then, in a space 24 formed after removing the metal cone member 4, as shown in FIG.
The metal rod 1 embedded in the concrete 19 and the retaining member 18 are closed by closing the space 24 with an adhesive applied thereto.
To protect from outside. In order to prevent rust from being generated on the metal rod 1 and the retaining member 18, the length from the large-diameter end face of the filling member 25 to the bottom surface of the concave portion 29 for fitting the screw 3 of the metal rod 1 is set. It is preferable to set the height H to about 50 to 120 mm.

As described above, the space 24 formed by the metal cone member 4 is completely closed by the filling member 25, so that water does not enter the interior of the concrete 19, and , And concrete 19 are made of substantially the same material, so that there is no difference in thermal expansion between the two,
The generation of cracks at the boundary and the like can be prevented. As a result, it is possible to effectively prevent rust from being generated on the reinforcing bar disposed inside together with the metal rod 1 and the retaining member 18, and the durability of the concrete 19 is further improved.

Further, since the anchor structure A can be used also as a formwork and a scaffold, workability on site can be improved and construction cost can be reduced. In addition, the dual-purpose structure using the two-step bolt 8 allows the perforation 16 of the curtain plate 15 to be set to a small diameter, and the fixing of the scaffold 11 requires the use of the large-diameter fastening bolt 12. High strength can be secured.

It should be noted that the anchor structure A of the present invention can be appropriately applied to the construction of a structure formed of concrete without being limited to the shaving insect method. Further, the shape of the filling member 25 is not limited to the shape shown in FIG. 5, as long as the space 24 can be completely closed, for example,
It may be a truncated cone having no recess 29.

[0021]

According to the present invention, the anchor structure A fixed to the formwork 9 can be used also for fixing the scaffold 11, and the efficiency of the construction work is improved. .

According to the second aspect, the two-step bolt 8 integrally formed with the small-diameter screw 10 and the large-diameter screw 13 is screwed into the fastening portion 5 of the metal cone member 4. Perforation of 16
Can be set to a small diameter, and the fixing of the scaffold 11 can use a large-diameter fastening bolt 12 to secure necessary strength.

The cavity 24 formed after removing the metal cone member 4 is closed by the filling member 25 made of substantially the same material as the concrete 19, so that the water inside the concrete 19 is filled. There is no intrusion, and no difference in thermal expansion occurs between the filling member 25 and the concrete 19, so that it is possible to prevent cracks from being generated at the boundary and the like.
As a result, it is possible to effectively prevent rust from being generated on the reinforcing bar disposed inside together with the metal rod 1 and the retaining member 18, and the durability of the concrete 19 is further improved.

[Brief description of the drawings]

FIG. 1 shows an anchor structure A according to an embodiment of the present invention.
It is principal part sectional drawing of.

FIG. 2 is a cross-sectional view when a form is filled with concrete.

FIG. 3 is a sectional view showing a state where a scaffold is attached.

FIG. 4 is an explanatory view at the time of removing the metal cone member.

FIG. 5 is a cross-sectional view showing a state where a filling member is filled in a space.

FIG. 6 is a side view of a scaffold attached to a block body.

FIG. 7 is a side view of a pipe scaffold installed around a block body.

FIG. 8 is a plan view of a block body.

FIG. 9 is a cross-sectional view showing an example of a conventional anchor structure embedded in concrete.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal rod 3 Screw 4 Metal cone member 5 Fastening part 8 Two-step bolt 9 Formwork 10 Fastening member 11 Scaffolding 12 Fastening member 13 Large diameter screw 19 Concrete 24 Empty space 25 Filling member

Claims (3)

[Claims] 1. A metal rod 1 having a screw 3 formed at an end thereof;
A metal cone member 4 screwed into the screw 3 of the metal rod 1.
An anchor structure A embedded in concrete 19 in a state where the large-diameter end surface of the metal cone member 4 is exposed to the surface. An anchor structure provided with a fastening portion 5 for detachably fixing a fastening member 10 attached to a concrete casting formwork 9 and a fastening member 12 attached to a scaffold 11. 2. The fastening portion 5 of the metal cone member 4 includes:
The large-diameter bolt 8 in which a small-diameter screw 10 for fixing the formwork 9 and a large-diameter screw 13 having the same diameter and the same pitch as the fastening member 12 for fixing the scaffold 11 are integrally formed. 2. The anchor structure according to claim 1, wherein a female screw for screwing the diameter screw is formed. 3. A concrete casting form 9 comprising a metal rod 1 having a screw 3 formed at an end thereof and a metal cone member 4 screwed to the screw 3 of the metal rod 1, and an anchor serving also as a scaffold 11. The structure A is buried in the concrete 19 to expose the large-diameter end surface of the metal cone member 4 to the surface, and the screwing of the metal cone member 4 to the metal rod 1 is released. 4. A method for constructing an anchor structure, comprising: removing a space (4); and closing a space (24) formed by the metal cone member (4) with a filling member (25) made of a material substantially the same as the concrete (19).