JP2884440B2 - Formwork for construction of concrete prism and construction method of column using it - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precast concrete (hereinafter referred to as "P") for use in the construction of reinforced concrete columns.
C) and related to the construction method using the form, especially when the square pillar of the building is converted to PC
The present invention relates to a PC-made outer formwork.

[0002]

2. Description of the Related Art In a conventional column construction method, PCs are being used for frame members in response to a demand for rationalizing the construction method of a building. When constructing a reinforced concrete column, the outer periphery of the column is required. The part is manufactured as a PC member to form a formwork, concrete is cast therein, and the formwork is left as a finishing member. This method is also used for square pillars. On the other hand, it is known to improve the structure of a reinforcing steel material by arranging a steel plate on an outer peripheral portion in a cross section of a reinforced concrete column, and to use this steel material alone for an outer formwork.

[0003]

As described above, when a reinforced concrete column is made into a PC, centrifugal molding can be used particularly when a steel plate is used on the outer peripheral surface, so that the PC is effectively promoted. However, in reality, there is a problem that the PC manufacturing factory is busy and the production capacity has reached its limit, and the situation is that it cannot meet the demand of the construction industry. Furthermore, in recent years, with regard to the conversion of pillars into PCs as described above, attention has been paid to the technology for manufacturing fume pipes used in civil engineering technology, and centrifugal molding techniques have been utilized in the manufacturing of PC formwork as described above. ing. However, centrifugal molding is advantageous when the cross section is circular, and can be manufactured as a PC member by effectively arranging a steel material on the outer periphery of the column cross section. For columns, centrifugal molding for square hollow sections is performed using PC.
It is a burden on the factory, and it is required to improve the efficiency according to the above circumstances. In addition, the construction method of using only the formwork part of the concrete work of the pillar as the PC, and the center part of the pillar together with the beam part or the connection part with the beam and the slab part, as well as the post-cast concrete, has a relatively short history at present. No means of setting the PC part at the site has been proposed.
The reliability of the bond strength between the two concrete parts is an issue to be solved.

[0004]

SUMMARY OF THE INVENTION In view of the above situation, the present invention has been made to solve the problems in the conventional method, and concrete is put into the inside using a steel plate as an outer frame. In a PC form for constructing a concrete column formed by centrifugal molding, the outer form is formed into a square cross section by a steel plate, and inside thereof, reinforcing reinforcing bars are arranged, and at a predetermined thickness, The purpose of the present invention is to provide a formwork for constructing a concrete prism, which is characterized in that a prefabricated square inner formwork is installed and concrete is put between the two forms and molded. It is an object of the present invention to disclose detailed techniques to a PC formwork and to provide a construction method of a prism using the same.
As a result, when the columns are made of reinforced concrete and the outer peripheral portion is made of a permanent form, a PC formwork or a steel form-coated PC formwork and a method of constructing a prism using the formwork are completed. In addition, since techniques such as centrifugal molding have been developed for a circular section in a developmental manner, a square section generally used in a building is generally described below.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the drawings of an embodiment employing a reinforced concrete column construction method. First, the ordinary construction method will be described in the order of steps.
In the frame of the building 1, 2 is a column having a rectangular horizontal section, 3 is a floor surface, 4 is a beam, 5 is a slab on an upper floor, and 6 is a column 2
7 is the hoop reinforcement, 8 is the reinforced cage, 9
Is a joint (panel zone) of a column and a beam. The construction of the pillar 2 is performed in the following steps. 4A and 4B, a reinforcing bar 8 of the floor formed by attaching a hoop bar 7 to the main bar 6 is connected to a connecting portion of the main bar 6 protruding from the floor surface 3 and c.
In the figure, a hollow cylindrical formwork 10 made of PC, which is manufactured in advance and has a rectangular shape as shown in FIG. The cylindrical form 10 is composed of a concrete portion 11 having a predetermined thickness so as to form an outer peripheral portion of the column 2 and a reinforcing steel bar 12 arranged inside the concrete portion 11, and a hollow portion 13 is formed therein. Have. Next, the cylindrical formwork 10 is supported from four sides by an appropriate support material (for example, a support, a chain, or the like), and cast-in-place concrete (vertical portion) is cast into the hollow portion 13. Next, in the step shown in FIG.
The beam 4 is erected with its end supported on the top of the cylindrical form 10 and the hoop 7 of the joint 9 between the column and the beam is assembled. Next, in FIG. B, the slab form 51 formed on the beam 4 by the PC plate is used.
And the concrete of the joint 9 and the slab 5 is cast as a horizontal part in FIG. Of course, beam 4 is P
C is easy to manufacture, and the manufacturing and erection methods have been established. The slab 5 is shown by a half slab method. 4 and the slab 5 may be integrally formed.

A cylindrical formwork 10 for constructing a prism according to the present invention.
Will be described with reference to the cross-sectional view of FIG. The cylindrical form 10 is
It consists of a concrete portion 11 and a reinforcing steel bar 12 arranged inside thereof, and a hollow portion 13 inside thereof is filled with cast-in-place concrete 14, and a precast concrete formwork is integrally disposed. Column 2 is formed.

FIG. 2 is a cross-sectional view of the cylindrical mold 10 at the time of manufacture, and reference numeral 20 denotes an entire centrifugal molding apparatus. The molding device 20 includes an outer mold frame 21, an inner mold frame 22, and a space 23 for placing concrete between the two. The outer frame 21 is made of a steel plate, and is formed hollow by assembling the surrounding four sides, and is supported at both ends by the turntable 24 of the centrifugal molding device 20. The inner dimension of the outer mold frame 21 has the dimensions of the column 2. The inner mold 22 is also made of a steel plate.
Is installed at a space 23 equal to the thickness of the concrete portion 11 from the inner surface of the
Is supported by a rotary disc 24 of the first embodiment. An uneven surface 25 is formed on the outer surface where the inner mold 22 is in contact with the concrete portion 11, and the uneven surface 25 has, for example, a ratio of depth to width of 1:
A cotter may be formed on the entire inner surface of the concrete portion 11 or at the four corners thereof. The connections at the four corners of the inner mold frame 22 are assembled so that the outer dimensions can be reduced inward. In the centrifugal molding apparatus 20 configured as described above, the concrete 11 is put into the space 23 to operate the apparatus, and after the concrete is hardened, the mold is removed so that the inner mold 22 can be dismantled inward from an appropriate surface. For example, the assembly is performed by interposing at least one of the four corners with a small wedge-shaped formwork 26 tapered outward and reduced. FIG. 3 shows an end of the cylindrical formwork 10. Inserts 15 are buried in the lower end portion of the cylindrical form 10 which is in contact with the floor surface 3 at three or more places on the end surface, usually on each side, and screw bolts 16 are screwed therein.

The PC formwork of the present invention is, of course, not limited to the above-described embodiment. As another embodiment, the outer formwork 21 made of the steel plate of the cylindrical formwork 10 is kept without being removed. Thus, the PC formwork coated with the steel plate can be used, and can be equivalent to the finished material of the outer surface of the column 2 itself. In this case, not only the outer dimensions are made to match the dimensions of the column 2, but also the outer peripheral surface is smoothed and assembled, and the inner surface is provided with studs for integration with concrete. In this structure, by arranging the steel material on the outer peripheral portion, the strength of the formwork itself and the structure of the column 2 can be improved, the wall thickness can be reduced, and the reinforcing steel bars 12 can be reduced or completely eliminated.

[0009]

The operation of the PC column formwork of the present invention having the above-described structure will be described based on a manufacturing method thereof. First, when the cylindrical formwork 10 for the column 2 is manufactured as a PC member, a predetermined length,
It is formed to the width and thickness of each side. Operation of the centrifugal molding device 20,
Although the operation is omitted, as shown in FIG. 2, first, the outer frame 21 is manufactured in a rectangular shape, and the reinforcing reinforcing bar 12 is mounted on the inner surface thereof through an appropriate spacer. Next, the inner mold 22 is assembled, fixed to the turntable at both ends, and concrete is put into the space 23. By the operation and operation of the high-speed rotation of the centrifugal molding device 20, the concrete 11 is compacted to the outer peripheral portion and molded into a predetermined shape, and the cylindrical form 1 in which the reinforcing reinforcing bar 12 is built therein.
0 is formed. After curing, the small formwork 26 at the corner is extracted, the inner formwork 22 is sequentially removed, and then the outer formwork 21 is removed, whereby the hollow cylindrical formwork 10 is obtained. Outer formwork 2
When 1 is left as it is as the coated steel material of the column 2, it is needless to say that its configuration is considered according to the purpose.

Next, a method of constructing the column 2 using the cylindrical formwork 10 will be described. The steps basically correspond to the steps described with reference to FIGS. However, in the cylindrical formwork 10 of the present invention, at the stage of the figure c, the four normal screw bolts 16 screwed to the lower end are advanced and retreated, and the verticality of the column 2 is adjusted by the projection size from the lower surface. I do. Since the screw bolt 16 protrudes by about 3 cm to keep the cylindrical form 10 floating, if the periphery is surrounded by the form, a base mortar formed horizontally for installation is unnecessary. Further, at the stage of the diagram c, in the casting of the cast-in-place concrete 14 inside the column 2, the uneven surface 17 on the inner surface of the concrete portion 11 formed by the uneven surface 25 of the inner formwork 22 is in contact with the cast-in-place concrete. Since a shear cotter is formed therebetween, the integration of the PC of the cylindrical formwork 10 and the cast-in-place concrete 14 is improved. In the sectional view shown in FIG.
The recess 18 formed on the inner surface is shown as the actual state at the time of centrifugal molding. The concave portion 18 is formed by the concentration of the excess water in the concrete 11, and as described above, the portion where the part of the uneven surface 17 is not formed by the uneven surface 25 is naturally formed. A large vertical cotter with a moderately rough surface will be formed instead. Therefore, the uneven surface 25 formed on the inner mold 22 may be formed only at four corners. Here, although the prism has a disadvantage in transmitting the interfacial shear force between the concrete and the round pillar, the thickness of the concrete portion 11 or the strength of the steel plate plus the steel plate can handle the lateral pressure of the cast-in-place concrete 14. Since it is a thickness, it can be compensated by its rigidity.

[0011]

[Effect of the Invention] The concrete formwork for the construction of the concrete prism of the present invention uses a steel plate as an outer formwork and puts concrete inside,
PC for construction of concrete columns formed by centrifugal molding
In the formwork, the outer formwork is formed in a rectangular shape in cross section by a steel plate, and a reinforcing steel bar is arranged inside the outer formwork, and an assembling type rectangular shape having an uneven surface formed on the outer surface at a predetermined thickness. Since the mold is installed and concrete is put between the two molds and molded, the inner mold is used for the production of the centrifugally molded PC tubular mold, and the square cylinder is used. Thus, not only the effect of utilizing a permanent form as a permanent form can be utilized, but also the integration with cast-in-place concrete is improved by forming a shear cotter by the uneven surface of the inner form. Also, such a P
In the method of constructing a prism using a C-shaped frame, the step of connecting the main reinforcement of the floor and the hoop reinforcement to the main reinforcement of the column protruding from the floor at the column installation position, extrapolating from above the reinforced cage, A step of suspending a precast concrete formwork having a hollow square cross section corresponding to the outer peripheral portion and having an uneven surface formed on the inner surface,
Using an adjusting screw provided at the lower end of the precast concrete formwork, adjusting the verticality of the column, casting concrete of the column into the hollow portion of the formwork, using a precast concrete member or formwork, Columns, joints of beams, including the step of concrete casting of beams and slabs, while it is a method according to the prior art, while it is easy to adjust the verticality of the column,
Not only is the intended labor situation solved and the construction period is shortened, but also the advantages of using a PC can be fully utilized. Accordingly, the present invention provides an embodiment having remarkable progress in a PC-made form used for construction of a reinforced concrete column and a construction method using the form, and having various degrees of freedom. Can make a truly significant contribution to the construction industry.

[0012]

[Brief description of the drawings]

FIG. 1 is a horizontal sectional view of a rectangular concrete column including a cylindrical formwork for constructing a prism according to the present invention.

FIG. 2 is a sectional view of a centrifugal molding apparatus.

FIG. 3 is a vertical sectional view of a lower portion of a cylindrical formwork.

FIG. 4 is a schematic elevation view illustrating the first half of a construction method for implementing the present invention in the order of steps.

FIG. 5 is a schematic elevation view illustrating the latter half of the construction method for implementing the present invention in the order of steps.

FIG. 6 is a cross-sectional view illustrating a molding state of the PC formwork of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Building 2 Column 3 Floor surface 4 Beam 5 Slab 6 Main reinforcement 7 Hoop reinforcement 8 Reinforcement cage 9 Joint of pillar and beam 10 Cylindrical formwork 11 Concrete part 12 Reinforcing reinforcement 13 Hollow part 14 Cast-in-place concrete 15 Insert 16 Screw bolt 17 uneven surface 18 concave portion 20 centrifugal molding device 21 outer mold frame 22 inner mold frame 23 space 24 turntable 25 uneven surface 26 wedge-shaped small form frame 51 slab form frame

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI E04C 3/30 E04C 3/30 (72) Inventor Kazuhiro Hatakeyama 2-6-1 Kyobashi, Chuo-ku, Tokyo Shimizu Corporation (72) Inventor Yoichi Seki 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Michio Hagiri 2-6-1 Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Koji Yamanobe 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Haruo Nakazawa 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Koji Ehara 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Haruhi Mazume Older 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (56) Reference JP-A-2-41203 (JP, A) JP-A-3-275305 (JP, A) JP-A-3-19805 (JP, A) Jikken Sho 31-20268 (JP, Y1) (58) Field (Int.Cl. ⁶ , DB name) E28B 1/20 E28B 7/30 E28B 21/38

Claims (5)

(57) [Claims] 1. A precast concrete formwork for constructing a concrete column formed by centrifugally casting concrete into a steel sheet as an outer formwork, and forming the outer formwork into a square cross section by a steel sheet. Inside, a reinforcing steel bar is arranged, and at a predetermined thickness, a prefabricated square inner formwork with an uneven surface formed on the outer surface is installed, and concrete is put between both forms and molded. A formwork for constructing a concrete prism. 2. The concrete formwork for constructing a concrete prism according to claim 1, wherein the steel sheet used for the outer formwork remains after being formed and is evaluated as a column structure. 3. The concrete prism according to claim 1, wherein at least one of the four corners of the inner mold is provided with a demolding means that can be reduced inward. Formwork. 4. The precast concrete form according to claim 1, wherein a plurality of inserts are buried at a lower end of the precast concrete formwork, and the verticality can be adjusted by screw bolts screwed into the inserts. The formwork for the construction of the described concrete prism. 5. A step of connecting a main reinforcing bar of a floor and a hoop reinforcing bar to a main reinforcing bar of a column protruding from a floor surface at a column setting position, and extrapolating from above the reinforcing bar to form a hollow square corresponding to the outer peripheral portion of the column. A step of suspending a precast concrete formwork having a cross section and having an uneven surface on the inner surface, a step of adjusting the verticality of the column by an adjusting screw provided at a lower end of the precast concrete formwork, Precast concrete formwork, comprising the step of: casting concrete into columns, concretely casting columns, joints of beams, beams and slabs using precast concrete members or forms. The construction method of the prism using.