JPH0689564B2 - Construction method of centrifugally formed steel rod reinforced concrete structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of use" The present invention is used as a pillar or beam structural member of a building, and is formed by connecting centrifugally-formed steel rod-reinforced concrete members covered with steel pipes and assembled. The present invention relates to a method for constructing a rod-reinforced concrete structure.

“Conventional technology and its problems” Conventionally, the construction method of this type of centrifugally-formed steel rod reinforced concrete is not known, and as a technology close to this, there is a construction method of reinforced concrete (RC) or steel frame reinforced concrete (SRC). The construction method of steel pipe concrete piles is known.

The RC and SRC construction methods consist of arranging reinforcing bars, surrounding them by forming a formwork on site, and then filling the inside of the formwork with concrete. That is, in these RC and SRC construction methods, for example, when connecting the members such as pillars and beams in the middle of the members, connect the reinforcing bars protruding from the end faces of the upper and lower pillars with a coupler, etc. Cover the surroundings with a formwork at the construction site,
Connection is made by filling the inside of the mold with mortar or the like.

However, in the RC method and SRC method described above, it is necessary to assemble a formwork at the construction site and to place a large amount of concrete at the site, and the construction cost increases due to the shortage of workers in recent years. Therefore, a lot of manpower, construction time, construction cost, etc. are required, and there is a problem in construction management.

In addition, centrifugally-formed steel rod reinforced concrete is known to be applied to a steel pipe concrete pile, and the steel pipe concrete pile is manufactured by incorporating a reinforcing bar inside the steel pipe and then filling the inside of the steel pipe with concrete. Then, it is constructed by centrifuging.

However, in this steel pipe concrete pile, when connecting the piles on the way, they are joined only by welding the steel pipe part, and it cannot be said that the stress transmission between members is sufficient, and furthermore, during this welding. There is a problem in quality control such that the high temperature during welding adversely affects the concrete inside. Therefore, the technology relating to the construction method which is the object of the present invention and has no problems in terms of construction control and quality control has not been established.

The present invention has been made in view of the above problems, using the centrifugally formed steel rod reinforced concrete member as a building structure, it is possible to easily connect the centrifugally formed steel rod reinforced concrete members, and, To provide a method for constructing a centrifugally-formed steel rod reinforced concrete structure that can reliably transmit the axial force of a structure such as a column formed by connecting to each other and has no problem in quality control. Has an aim.

"Means for Solving the Problem" The present invention extends inside a first steel pipe having a predetermined length in the axial direction with substantially the same length dimension as the first steel pipe, and at a predetermined time along the circumferential direction. A plurality of first rebars arranged at intervals are provided, and further, the first rebars are included by centrifugal molding, and at the same time, the first rebar is retracted by a predetermined dimension from both ends of the first steel pipe to the first lining concrete. While the first centrifugally-formed steel rod reinforced concrete member subjected to the above is manufactured, the first lining concrete from the both end portions of the second steel pipe is provided inside the second steel pipe having a predetermined length. While protruding to a length about the same as the retracted size from both ends,
A plurality of second reinforcing bars arranged at predetermined intervals along the circumferential direction are provided at different positions in the radial direction of the first reinforcing bar and the steel pipe, and further, the second reinforcing bars are enclosed by centrifugal molding so as to include the second reinforcing bars. The second centrifugally-formed steel rod reinforced concrete member with the lining concrete No. 2 is manufactured, and one of the first and second centrifugally-formed steel rod reinforced concrete members is arranged, and then the other is joined to the steel pipe joint. To the first and second centrifugally formed steel rod reinforced concrete members, and then filling the gap formed between the first and second lining concrete of the first and second centrifugally formed steel rod reinforced concrete members with mortar to form a centrifugally formed steel rod reinforced concrete structure. Is to be constructed.

"Operation" In the construction method of the centrifugally formed steel rod reinforced concrete structure of the present invention, since it is configured as described above,
After arranging the centrifugally-formed steel rod reinforced concrete member, when the first centrifugally-formed steel rod reinforced concrete member is brought into contact with the steel pipe joint, it is formed between the first and second lining concretes. A second reinforcing bar protruding from the second steel pipe is arranged in the gap, whereby the first reinforcing bar and the second reinforcing bar overlap each other at different radial positions, and by filling the clearance with mortar, The first reinforcing bar and the second reinforcing bar are fixed to form a lap joint, and the first and second centrifugally formed steel rod-reinforced concrete members are mechanically connected. Then, in this state, if the first steel pipe and the second steel pipe are butt-welded together,
Then, the second centrifugally formed steel rod-reinforced concrete member is further firmly connected and constructed.

[Examples] Hereinafter, the present invention will be described with reference to the drawings.

1 to 6 show an embodiment in which the method for constructing a centrifugally-formed steel rod-reinforced concrete structure of the present invention is applied to a column, and the symbol H in the drawings denotes a centrifugally-formed steel rod-reinforced concrete structure. It is a pillar as an example.

First, the outline of the first centrifugally formed steel rod reinforced concrete member H1 (hereinafter simply referred to as member H1) used in the construction method of the present embodiment will be described with reference to FIG. H1 is located inside the first steel pipe 1 having a predetermined length.
The first steel pipe 1 is provided with twelve first reinforcing bars (steel rods) 2 that extend in the axial direction with substantially the same length as the steel pipe 1 and are arranged at regular intervals along the circumferential direction of the first steel pipe 1. Has been. And the said 1st rebar 2 is enclosed in the inside of the 1st lining concrete 3 shape | molded by the centrifugal shaping | molding, and this 1st lining concrete 3 is predetermined inside from the both ends of the 1st steel pipe 1. The dimensions have been set back. The set-back lining concrete 3 is formed with a slope that gradually expands in diameter as it approaches the outside of the steel pipe. From the slope, both ends of the first reinforcing bar 2 are connected to the first steel pipe 1. It is designed to project up to the vicinity of the end face.

Next, the second centrifugally-formed steel rod reinforced concrete member H2 (hereinafter simply referred to as member H2) will be described with reference to FIG. 6, and the second member H2 has a second length of a predetermined length. A second reinforcing bar (steel rod) 12 is provided inside the steel pipe 11.
12 extend in the axial direction with a length projecting from both end portions and are arranged at regular intervals in the circumferential direction. Further, the second reinforcing bar projects from both ends of the steel pipe with a length dimension slightly shorter than the length dimension in which the first lining concrete is set back, and the first reinforcing bar 2 is arranged. It is provided so as to be located closer to the center of the steel pipe 11 than the radial position. The second reinforcing bar 2 is contained in the second lining concrete 13 formed by centrifugal molding. Further, at both ends of the second steel pipe 11, the end face plate 14a and the tubular member 1 are provided.
The inner formwork member 14 formed by 4b is fixed, and the inner formwork member 14 is fitted inside the first lining concrete to align the members H1 and H2, It is configured to serve as a mold for injecting mortar into a gap S formed by the inner mold member and the steel pipe 1. The tubular member 14 of the inner mold member 14
An air vent hole h2, which will be described later, is formed near the tip of b.

Next, the first and second members H1 and H2 configured as described above
Fig. 1 and Fig. 2 (a) for a pillar H formed by using
Will be described with reference to. The pillar H includes a first member H1 and a second member H1.
And the member H2 of (1) are connected to each other at an intermediate point of each floor (that is, near the inflection point of the moment applied to the pillar H).

The lower end of the first lining concrete 3 formed on the inner peripheral surface of the first member H1 is fitted with the upper end of the inner formwork member 14 fixed to the upper portion of the second member H2. In the annular gap S defined by the inner formwork member 14, the steel pipe 1 and the first lining concrete 3, the lower end portion of the first rebar 2 extending downward from above and extending from below to above are provided. The upper end portion of the existing second reinforcing bar 12 is arranged at a different position in the radial direction (double in a shape surrounding the center on the plane about the central axis of the steel pipe).

Then, the mortar M is filled in the gap S in which the first and second reinforcing bars 2 and 12 are arranged, whereby the first and second
Of the rebar is mechanically connected to the lap joint. Further, the end surfaces of the upper first steel pipe 1 and the lower second steel pipe 2 are welded to each other at a steel pipe joint J.

Therefore, in the pillar H of this embodiment, the upper and lower members H1, H2
The axial force and moment acting on the can be transmitted.

Next, with reference to FIG. 3 and FIG. 4 (a), a procedure for carrying out the method for constructing the pillar H as the centrifugally-formed steel rod-reinforced concrete structure of this embodiment on site will be described.

(I) First, as shown in FIG. 3, the first member H1 is placed on the upper portion of the second member H2 manufactured as described above with their central axes aligned.

(Ii) Next, as shown in FIG. 4 (a), the second member
The member H1 is installed on the upper part of H2, and the steel pipes of the first steel pipe and the second steel pipe are connected to each other by butt-welding the steel pipe joint portions of the pipes.

At that time, the tip of the inner formwork member 14 is in a state of being fitted near the lower end of the first lining concrete,
The inner formwork member, the first steel pipe, and the lining concrete 3
A gap S is formed between the first rebar 2 and the second rebar 12 in the form of a lap joint.

(Iii) Next, after forming a mortar inlet h1 near the bottom of the first member H1 with an electric drill or the like,
The gap S is filled with mortar from h1 and the mortar is caused to flow out from the exhaust port h2 of the already formed mold member,
The state shown in FIG. 1 is assumed.

Thus, in the method of constructing the pillar H of the present embodiment, when the upper member H1 is built into the lower member H2, the inner form member 14
Is a construction method that fits into the lining concrete 3 of the first steel pipe and enables easy alignment, and a gap S is formed between the inner formwork member, the first steel pipe, and the first lining concrete. Is formed, and the first rebar and the second rebar are fixed in the gap S by the mortar to form a lap joint, and the first and second rebars are not directly connected. It is possible to transmit the axial force and moment of the members H1 and H2 of.

Therefore, in the case of the present embodiment, it is not necessary to assemble a mold, and the members H1 and H2 can be mechanically and strongly connected,
It is possible to improve workability and reduce construction costs. Since the members H1 and H2 are connected to the pillar H of this embodiment at an intermediate point on each floor, which is an inflection point of the moment, the structure has sufficient strength.

Of course, after the members H1 and H2 are built in, the inside of the lining concrete in the members H1 and H2 can be filled with concrete to improve the strength of the column.

Further, in the above embodiment, the member H1 is built in the upper part of the member H2, but the present invention is not limited to this, and the member H1 is built in the upper part of the member H1.
H2 may be built in.

Although the embodiment described above is a case where the column H is constructed by the method of the present invention, the method of the present invention can be similarly applied to other centrifugally formed steel rod-reinforced concrete structures such as beams. When applied to a beam, the cross section of the member may be a rectangular cross section, and the vertical relationship in the above embodiment may be replaced by the horizontal relationship.

The cross section of the member is not limited to the circular shape, and the cross section shown in FIG.
It may be polygonal as shown in FIG.

In addition, a member is provided on top of the second member H2 shown in FIG. 4 (a).
As a modification example in which H1 is installed and these steel pipes are connected by butt welding the steel pipe joint portions of the first steel pipe and the second steel pipe, as shown in FIG. 4 (b). If the lining concrete 3 of the first member H1 is shaped to incline upward as it goes to the outside, and the air vent hole h2 is formed in the steel pipe 1 so as to be located immediately below the lining concrete, When the mortar is filled in the gap S formed inside the steel pipe, air is sufficiently released and the mortar is satisfactorily filled.

Furthermore, the inner formwork member is not limited to the above-described shape, and can be appropriately modified in design.

"Effects of the Invention" As described above, in the method for constructing a centrifugally-formed steel rod-reinforced concrete structure of the present invention, the first lining is set back from both end faces of the first steel pipe to the inside by a predetermined length. Along with applying concrete, a second rebar is provided by projecting the set back of the first lining concrete from both end faces of the second steel pipe, and the first centrifugally formed steel rod reinforced concrete member and the second Since the first rebar and the second rebar are fixed by mortar after the centrifugally-formed steel rod reinforced concrete member of No. 1 is built, it is necessary to disassemble the formwork as in the conventional construction method. Not only that, the construction cost can be greatly reduced and the number of workers can be reduced, and the construction period can be shortened. Furthermore, it can be used as a pillar or beam for building structure. In addition, the members can be easily connected in the middle of the member, and the force acting on the member, that is, the moment and the axial force can be surely transmitted to the other member.

[Brief description of drawings]

The drawings show an embodiment in which the method of the present invention is applied to a case where a column as a centrifugally-formed steel rod reinforced concrete structure is constructed. FIG. 1 is a side sectional view showing a main part of a column constructed by the method of this embodiment, and FIG. 2 (a) is a II- of FIG.
2 is a plan sectional view of a circular column showing a II cross section, FIG. 2B is a plan sectional view of a square column showing a II-II cross section of FIG. 1, and FIG.
4B is a side sectional view showing a state in which the first member is aligned with the member of FIG. 4, FIG. 4A is a side sectional view showing a state in which the first member is built in the second member, and FIG. ) Is a side sectional view of another embodiment showing a state in which the first member is built in the second member, and FIG. 5 is a side sectional view of the first member used in the construction method of the present embodiment. The figure also shows the second embodiment used in the method of this embodiment.
It is a side sectional view of the member of. H: Pillar (centrifugal molded steel rod reinforced concrete structure), H1
…… The first centrifugally formed steel rod reinforced concrete member, H2 ……
Second centrifugally formed steel rod reinforced concrete member, J ... Steel pipe joint, 1 ... First steel pipe, 2 ... First rebar (steel rod), 3 ... First lining concrete, 11 ... 2nd steel pipe, 12 ... 2nd rebar (steel rod), 13 ... 2nd lining concrete, 14 ... inner formwork member.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenichi Ikeda 2-16-1 Kyobashi, Chuo-ku, Tokyo Within Shimizu Construction Co., Ltd. (72) Inventor Koichi Nakamura 2-16-1 Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Hideyo Shiokawa 2-161-1 Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Takanori Sato 2-16-1 Kyobashi, Chuo-ku, Tokyo Shimizu Ken Inside the corporation

Claims (1)

[Claims] 1. A plurality of first steel pipes having a predetermined length, which extend in the axial direction with substantially the same length dimension as the first steel pipe and are arranged at predetermined intervals along the circumferential direction. A first centrifugal molding in which a first reinforcing bar is provided, and further the first reinforcing bar is encapsulated by centrifugal molding and the first lining concrete is retracted from both ends of the first steel pipe by a predetermined dimension, and the first centrifugal molding is performed. While manufacturing the steel rod reinforced concrete member, the size of the first lining concrete retracted from both ends of the second steel pipe into the second steel pipe having a predetermined length is substantially the same as the size of the first steel pipe retracted from both ends. While protruding to a length of about
A plurality of second reinforcing bars arranged at predetermined intervals along the circumferential direction are provided at different positions in the radial direction of the first reinforcing bar and the steel pipe, and further, the second reinforcing bars are enclosed by centrifugal molding so as to include the second reinforcing bars. The second centrifugally-formed steel rod reinforced concrete member with the lining concrete of No. 2 is manufactured, and one of these first and second centrifugally-formed steel rod reinforced concrete members is arranged, and then the other is connected to the steel pipe joint. And then mortar is filled in the gap formed between the first and second lining concrete of the first and second centrifugally formed steel rod reinforced concrete members. Construction method of concrete structure.