JPH0689563B2 - Construction method of centrifugally formed steel rod reinforced concrete structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention connects centrifugally formed steel rod reinforced concrete members coated on steel pipes, which are used as structural members such as columns and beams of buildings, The present invention relates to a construction method for forming a centrifugally formed steel rod reinforced concrete structure.

"Conventional technology and its problem" Conventionally, the construction method of this type of centrifugally formed steel rod reinforced concrete structure is not known, and as a technology close to this,
Reinforced concrete (RC) and steel reinforced concrete (SR
C) construction method and steel pipe concrete pile construction method are 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 pillars in the middle of a pillar, connect the reinforcing bars protruding from the end faces of the upper and lower pillars with a coupler, etc., and around them at the construction site. The mold is covered and the inside of the mold is filled with mortar or the like so as to be connected.

However, in the RC method and SRC method mentioned above, it is necessary to assemble the formwork at the construction site, and the construction cost is increasing due to the shortage of workers in recent years. However, there was 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, It is possible to reliably transmit the axial force of a structure such as a column formed by connecting the pillars, and to provide a method of constructing a centrifugally-formed steel rod reinforced concrete structure without problems in quality control. Has an aim.

"Means for Solving the Problem" The present invention is to fix an annular first end face plate inside a steel pipe of a predetermined length slightly inside from one end face of the steel pipe, while the other end face of the steel pipe is fixed. An annular second end face plate is provided slightly further inward, and a cylindrical connecting member fitted to the inner diameter of the first end face plate is projected from the other end face of the steel pipe on the second end face plate. And a steel rod that extends along the longitudinal direction of the steel pipe and is fixed at predetermined intervals in the circumferential direction between the first end face plate and the second end face plate. Centrifugal forming using a centrifugally formed steel rod reinforced concrete member produced by supplying a predetermined amount of concrete to the inside of the steel pipe and then performing centrifugal forming using the steel pipe and the first and second end plates as a mold. After placing the steel rod reinforced concrete members in place, By connecting one ends of other centrifugally formed steel rod reinforced concrete members that are similarly configured to each other, the first and second end face plates of the centrifugally formed steel rod reinforced concrete members of both of them are opposed to each other and the connection is made. The member is fitted into the first end face plate, and thereafter, the mortar is injected into the space formed between the end face plates to construct the centrifugally formed steel rod reinforced concrete structure.

[Operation] In the centrifugally formed steel rod reinforced concrete structure of the present invention, since it is configured as described above, one centrifugally formed steel rod reinforced concrete member is applied to the other centrifugally formed steel rod reinforced concrete member. When contacted, the first end face plate formed near the end of one centrifugally formed steel rod reinforced concrete member is fitted with the connection member formed near the end of the other centrifugally formed steel rod reinforced concrete member. , Whereby the opposing centrifugally formed steel rod reinforced concrete members are easily positioned and connected. In this state, the opposite centrifugally formed steel rod reinforced concrete members are connected by welding the ends of the steel pipe portions of the opposite members.
In addition, the space formed between the first and second end face plates fixed to the centrifugally-formed steel rod reinforced concrete members of the companions can be filled with mortar later so that the space inside the companion steel pipes will be filled. Formed lining concretes are connected to each other, thereby forming a centrifugally formed steel rod reinforced concrete structure capable of mutually transmitting axial forces acting between members.

"Example" Hereinafter, an example of the method of the present invention will be described. The construction method of this embodiment described below is applied when constructing a pillar C of a building as a centrifugally formed steel rod reinforced concrete structure as shown in FIGS. 1 and 2.

First, referring to FIG. 7, a centrifugally-formed steel rod reinforced concrete member H (hereinafter simply referred to as member H) used in the construction method of the present embodiment, and if necessary, member H1 and member H2 are used.
(A distinction is made by adding subscripts as in the above). In this member H, the annular first end face plate 2 is set back inside the steel pipe 1 of a predetermined length slightly inward from one end face. It is fixed. Further, an annular second end face plate 3 is provided by being set back slightly inward from the other end face of the steel pipe. The steel pipe 1 is attached to the second end plate 3.
The cylindrical connecting member 4 that fits into the inner diameter of the first end face plate 2 is fixed by being projected from the other end face of the first end face in the axial direction by a predetermined length. As shown in FIG. 3, the connecting member 4 is a cylindrical body fixed to the inner peripheral surface side of the second end face plate 3, and is formed so that its diameter is reduced toward the tip and narrowed down. At the same time, by forming a plurality of split 4a along the longitudinal direction from the distal end to the proximal end side,
It is configured to be easily fitted inside the first end face plate 2.

Further, between the first end face plate 2 and the second end face plate 3 facing each other inside the steel pipe 1, the steel pipe 1 extends along the longitudinal direction and is arranged at predetermined intervals in the circumferential direction. The fixed steel rods 5, 5, ... Are fixed and the inner peripheral surface of the steel pipe is subjected to centrifugal molding using the steel pipe 1 and the first and second end face plates 2 and 3 as molds. By doing so, the concrete 6 is lined.

In addition, the above-mentioned steel rods 5, 5, ...
Both ends thereof may be welded and fixed to the end face plates 2 and 3 in advance, and these may be inserted and fixed at the above-mentioned arrangement positions inside the steel pipe 1, or may be fixed by tightening nuts or the like. Also,
A PC steel wire or the like may be used as the steel rod 5.

Next, the pillar C of the building formed by using the member H configured as described above will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, the pillar C is provided with an upper member H1.
And the lower member H2 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 C). A first end face plate 2 is fixed near the lower end of the upper member H1 by setting back from one end face of the steel pipe 1. In addition, near the upper end of the lower member H2, the steel pipe 1
The second end face plate 3 is fixed to the second end face plate 3 by slightly setting back from the other end face thereof, and the second end face plate 3 is fixed with the connecting member 4 projecting in the axial direction toward the upper steel pipe side. The upper and lower members H1 and H2 are connected in a state of being fitted inside the first end face plate. Furthermore, the steel pipes 1,1 of the upper and lower members H1, H2 have their end faces connected by butt welding, and the space formed between the end face plates of the upper and lower steel pipes 1,1 is filled with mortar 7. The upper and lower members H
It is designed to bear the axial force that acts on the connection between 1 and H2.

Inside the abutting portion of the steel pipe, a back metal plate 7 for welding, which is formed annularly on the inner peripheral surface of the lower steel pipe, is fixed.

Next, with reference to FIG. 4 to FIG. 6, a method of constructing the pillar C, which is an embodiment of the method of the present invention, will be described.

(I) First, as shown in FIG. 4, the member H2 manufactured by centrifugal molding is erected so that the second end plate is on the upper side, and the member H1 also manufactured by centrifugal molding is Place on top of H2.

At this time, a back metal plate 7 for welding is fixed to the upper end of the pillar H2, and an upper end face plate 3 and a connecting member 4 fixed to the upper end face plate 3 are attached slightly below the back metal plate 7. In the upper member H1, the center of the end plate 2 is located coaxially with the connecting member 4.

(Ii) Next, as shown in FIG. 5, the upper member H1 is built over the lower member H2.

At this time, the lower end surface of the upper member H1 and the upper end surface of the lower member H2 are butted against each other leaving a slight welding gap Y, and the connecting member 4 is inside the end face plate 2 of the upper member H1. It will be in a state of being fitted to. A space S for filling mortar is formed between the end plates 2 and 3 of the upper and lower steel pipes 1 and 1.

(Iii) Next, the space S formed between the end plates 2 and 3 of the members H1 and H2 is filled with mortar, and the end plates are filled with mortar.
By connecting the mortar filler between 2 and 3, by connecting the lining concrete of the upper member H1 and the lower member H2 separated by the state shown in FIG. 1, that is, the space S,
The axial force that the lining concrete bears can be transmitted downward.

As a method of filling the mortar, an upper communication hole h1 and a lower communication hole h2 communicating with the upper and lower parts of the gap S are formed on the side portions of the steel pipes 1, 1 by a drill or the like, and the lower communication hole h2 is formed.
It is considered that the space S is sufficiently filled with mortar by filling the space S with mortar from the side and confirming that the mortar filled through the upper communication hole h1 has flowed out of the steel pipe. .

Thus, in the method for constructing a centrifugally-formed steel rod concrete column of the present invention, when the upper member H1 is built in the lower member H2, the first member formed near the lower end of the member H1 to be built The upper and lower members H1 and H2 can be easily connected by fitting the connecting member 4 protruding upward from the second end face plate 3 formed near the upper end of the lower member H2 to the end face plate 1 of 1. To be done.

Furthermore, in this state, the upper and lower members H1 and H2 are connected by butt-welding the ends of the steel pipes together. Further, the space formed by the end plates 2 and 3 and the connecting member 4 near the connecting portions of the upper and lower members H1 and H2 is filled with mortar later to form a lining concrete formed inside the upper and lower steel pipes. Are axially connected so that the axial force acting on the lining concrete of the member H1 can be transmitted to the lower member H2.

Therefore, in the case of the present embodiment, it is not necessary to assemble a formwork at the construction site, and the members H1 and H2 can be connected without connecting the steel rods arranged inside the steel pipe. It is possible to improve productivity and reduce construction costs. In addition, since the members C1 and H2 are connected at the middle point of each floor, which is the point of inflection of the moment, in the pillar C of this embodiment, it is not necessary to connect the steel rods to each other, but the strength is sufficient. It has a unique structure.

Of course, after the members H1 and H2 have been built, it is possible to further fill the voids inside the lining concrete in the members H1 and H2 with concrete to further improve the strength of the column.

Although the embodiment described above is a case where the column C 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 it is used for 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 with the lateral relationship.

"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 following effects are exhibited.

(I) Since the centrifugally-formed steel rod reinforced concrete member in which the first and second end face plates are fixed to both ends of the steel pipe is used, the steel pipe and the first and second end face plates function as a formwork, and centrifugal separation is facilitated. A molded steel rod reinforced concrete member can be manufactured.

(Ii) By providing a connecting member on the second end face plate and fitting the connecting member to the first end face plate, the centrifugally formed steel rod reinforced concrete members can be easily positioned and connected together.
Also, in this state, since the end faces of the steel pipes are connected by butt welding, it is not necessary to connect the steel rods of the companion members, and there is no adverse effect of high heat due to welding on the lining concrete, so construction It is possible to improve the workability, improve the construction quality, and significantly reduce the construction cost.

(Iii) Further, since the mortar is injected from the outside into the space formed by the connecting member and the cross-section plate inside the steel pipe in the vicinity of the connecting portion of the member, the lining concrete of one steel pipe and the lining of the other steel pipe. It will be connected with concrete in the axial direction by mortar,
Axial forces acting on the members can be reliably transmitted to each other.

[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 formed by the method of this embodiment, FIG. 2 is a plan sectional view of the column showing a II-II section of FIG. 1, and FIG. It is a perspective view of the connecting member fixed to the end face plate. 4 to 6 are for explaining the construction procedure of the present embodiment. FIG. 4 is a side sectional view showing a state in which an upper member and a lower member are being connected, and FIG. FIG. 6 is a side sectional view showing a state where the upper member and the lower member are connected, and FIG. 6 is a side sectional view showing a state where the upper member and the lower member are welded. FIG. 7 is a cross-sectional view showing a centrifugally formed steel rod reinforced concrete member used in the method of this embodiment. C: pillar (centrifugal molded steel rod reinforced concrete structure),
H, H1, H2 ... Centrifugal molded steel rod reinforced concrete members, 1
...... Steel pipe, 2 …… First end face plate, 3 …… Second end face plate,
4 ... Connection member, 5 ... Steel rod, 6 ... Concrete (lining concrete).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takanori Sato 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Kenichi Ikeda 2-1-1-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction company (72) Inventor Yasushi Watanabe 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction company

Claims (1)

[Claims] 1. An annular first end face plate is fixed inside a steel pipe of a predetermined length slightly inside one end face of the steel pipe, while an annular first end face plate is positioned slightly inside from the other end face of the steel pipe. Second end face plate is provided, and a cylindrical connecting member that fits into the inner diameter of the first end face plate is provided on the second end face plate so as to project from the other end face of the steel pipe. Between the first end face plate and the second end face plate, steel rods extending along the longitudinal direction of the steel pipe and fixed at predetermined intervals in the circumferential direction, and further, a predetermined amount of concrete is provided inside the steel pipe. Of the steel pipe and the first and second end face plates are used as a mold, and a centrifugally formed steel rod-reinforced concrete member manufactured by performing centrifugal molding is used. After arranging the By connecting one ends of the formed steel rod reinforced concrete members, the first and second end face plates of the centrifugal formed steel rod reinforced concrete members of both of them are opposed to each other and the connecting member is fitted to the first end face plate. Then, after that, mortar is injected into the space formed between the end face plates, and the method for constructing a centrifugally-formed steel rod-reinforced concrete structure.