JPH0893137A - Precast post serving as form and construction method therefor - Google Patents

Abstract

PURPOSE: To provide a post which serves as a form which is capable of constructing every post without any need for a form and is easy to control and strong at low weight and easy to handle and construct. CONSTITUTION: Concrete 6 is designed to hold 0.8% and over reinforcing bars 4 and 0.2% and over hoops 5 to every cross section and provides a vertical through hollow 3 to fill the concrete where an outward form 2 has the outside shape of a finishing post. The concrete is filled therein as it is so that it may be a concrete post. Furthermore, additional internal main reinforcing bars and hoops are placed in the hollow part 3, which makes it possible to form composites post having high strength.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a building having a concrete structure, a precast concrete column (precast column) which is also used as a formwork for the structure, and a construction method thereof.

[0002]

2. Description of the Related Art There is known a technique in which a pillar of a building is manufactured from hollow precast concrete, which is used as a formwork to externally fit on the main reinforcing bar of the pillar to place the concrete. For example, Japanese Patent Publication No. 61-31261 and Japanese Patent Publication No. 1-3098
Japanese Unexamined Patent Publication No. 8 discloses a precast concrete cylinder having a hoop streak in the wall of the cylinder. This cylinder body is constructed by externally fitting the cylinder body to the main rebar of the pillar assembled at the site to form a formwork, and placing concrete inside to form the pillar.

Further, Japanese Utility Model Laid-Open No. 62-101909 discloses a precast concrete member for constructing a concrete column having a shear reinforcing material on the inner surface thereof, and further hoop reinforcements are densely arranged in a concrete wall ( Actual Kaisho 6
No. 2-101909), a reinforcing fiber net or a short fiber material is embedded or mixed (Japanese Utility Model Publication No. 62-101909).

All of the above conventional techniques are provided with only hoop reinforcements or reinforcing reinforcements equivalent thereto, and all the main reinforcing bars of columns are assembled on site.

[0005]

The present invention, unlike the conventional precast concrete hollow columns as described above, is capable of forming the columns by themselves. An attempt is made to provide a hollow column which is assembled and synthesized on-site and a method for on-site construction thereof.

The problems of the present invention are as follows. (A) A hollow pillar that does not require on-site bar arrangement as much as possible,
When necessary, the same precast concrete hollow columns can be used for all columns by arranging the main reinforcement and hoop reinforcements on site in the hollow part. (B) Producing good quality concrete at the factory.

(C) Light weight and high strength, and easy handling such as transportation and installation. (D) A formwork is not required when constructing the pillar, and the outer surface of the pillar is already made of precast concrete to provide a finished surface or an outer surface equivalent thereto. (E) Standardization is easy, versatility is high, and a small number of products can be used. (F) Full consideration should be given to the joint structure.

It is an object of the present invention to provide a precast column that also serves as a formwork and a method of constructing the same, which solves the above problems.

[0009]

The present invention is characterized by taking the following technical means in order to solve the above problems. That is, the present invention has an outer shape of a finished column, and holds the main reinforcing bar and the hoop reinforcing bar in the concrete wall,
It is a precast column that also serves as a formwork, characterized in that it is composed of a hollow column body having a hollow portion in which concrete is filled. This precast concrete hollow column has a main rebar amount of 0.8% or more of the entire cross section and a hoop rebar amount of 0.2% or more of the entire cross section, and has a minimum rebar amount.

The precast concrete hollow column of the present invention has a structure in which (A) main rebar extends from the upper end of the column into the beam-column joint, and (B) main rebar extends from the upper end of the column into the column base of the upper floor. By adopting one type of structure selected from the group of the structure shown (C) and the main rebar not extending from the upper end of the column, it is possible to join columns and beams that are suitable for each structure It is possible to have a good and excellent design.

In this case, a large number of rebars with claws surrounding the main rebar in the concrete wall and projecting ends in the hollow part are arranged near the lower end of the column or near the lower end and the upper end along the column axial direction. By setting it in advance, an excellent vertical connection structure can be easily obtained. In addition, if the length of the precast pillar is adjusted to the highest floor height of the building, and the pillar length of the portion where the claw bar is arranged is the length including the cutting allowance,
Since all the columns can be precast columns having the same size, and only one type can be used, the product of the present invention is extremely easy to manage.

Further, the precast column which also serves as the mold of the present invention can be easily manufactured by centrifugal molding, and is preferably made of centrifugally molded concrete. Next, using the precast column that also serves as the formwork according to the present invention, in constructing the concrete column, the precast column that also serves as the formwork, the lower end of which is projected onto the foundation or the beam at the column standing position. The lap joint is set up by fitting it over the vertical rebar, and then the precast upper-story beam or the upper-story beam form is placed on the stake to arrange the beam-column lap joint reinforcement and the floor half precast slab or slab form. After arranging in the upper slab position and after arranging the beam floor, filling the hollow part of the precast column that also serves as the formwork, the beam, and the floor concrete are placed. Adopt the construction method.

In this case, in a column in which a main reinforcing bar needs to be added inside, after assembling the required main reinforcing bar and hoop reinforcing bar in the column, a precast column that also serves as a formwork is externally attached to this assembled main reinforcing bar in this column. Just fit it.

[0014]

The precast column, which also serves as the formwork, of the present invention has the following function due to the above-mentioned configuration. (A) A precast concrete column that also serves as a formwork,
No formwork is required and the outer surface of the pillar is already formed. It should be noted that the outer surface of the column is not hindered from being further externally coated, and the outer surface finish suitable for the external coating can be prepared in advance. (B) A precast column of the same size that also serves as a mold can be used for all columns. In this case, a column having high strength can be constructed by constructing a shortage of reinforcing bars according to the required strength of the column in the hollow portion for filling concrete. Therefore, the pillar of the present invention is versatile, can be unified in the same size and the same product type, is easy to manage, and is rational to manufacture. (C) The legally required minimum amount of built-in rebar is secured. That is, the amount of main reinforcing bars is 12 or more, 0.8% or more for the entire column cross section, and the hoop reinforcement is 0.2% or more for the entire column cross section. (D) The shortage of main rebar and hoop rebar is arranged in the hollow part,
The yield strength can be a composite column structure that is the sum of the precast parts. (E) Since the main reinforcing bar is built in, the strength is high, and since it has a hollow portion, it is light in weight, easy to carry, store and handle, and the crane and the like are small in size, and the cost can be generally reduced. (F) The joint design is simple, and it is not necessary to increase the column cross section at the joint. (G) The joint portion is reinforced by the claw reinforcing bar. The length of the pillar is standardized according to the highest floor height, and when the floor height is low, it is possible to reduce the variety by cutting the top or bottom of the pillar to shorten the length of the pillar, but at this time, It is preferable that the arrangement length of the reinforcing bar with a claw at the upper end or the lower end is formed to be a length including a cutting allowance. (H) It will be a factory product that has been thoroughly quality controlled. Further, it can be easily manufactured by centrifugal molding, and it is possible to easily manufacture concrete whose outer surface is dense,
No inner formwork required during manufacturing. (I) The connection between the upper and lower structures of the column may be determined by designing the lap joint reinforcing bar according to the design, and the pre-assembly method of the lap joint reinforcing bar can also be adopted. Therefore, the workability is good, mechanical joints and sheaths are not required, and the work can be rationalized and the cost can be reduced.

Corresponding to the joint system of each lap joint, (A)
When the main rebar is extended from the upper end of the column into the beam-column joint,
The length of the joint rebar of the upper and lower columns can be shortened, (B)
It is preferable to extend the main reinforcing bar from the upper end of the column to the inside of the column base of the upper floor so that the number of reinforcing bars for on-site construction can be reduced, and the work is simplified particularly when the upper column does not require additional reinforcing bars. Further, (C) If the main reinforcing bar does not extend from the upper end of the column, the column can be manufactured, handled, and assembled easily, and the joint portion can be assembled by the lap joint tip assembly method. High and sufficient strength can be secured.

The method of constructing a concrete column according to the present invention uses the above-mentioned precast column that also serves as a formwork, so that no formwork is required and all the columns can be constructed with the same precast column, and the management is easy and the construction is easy. It will be easy. In addition, the design and construction of lap joints is easy. When constructing a column having higher strength, a composite column can be obtained by placing reinforcing bars in the hollow portion and placing concrete.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 (a) shows a cross-sectional view of a precast column 1 which also serves as a mold of an embodiment of the present invention, and FIG. 1 (b) shows a vertical cross-sectional view thereof. The precast column 1 that also serves as the formwork of the embodiment has a main rebar 4 and a hoop rebar 5 embedded in concrete 6, and has a hollow portion 3 penetrating in the longitudinal direction. Hollow part 3 is a hollow hole for pouring concrete, and pillar 1 is
At the time of on-site construction, it also serves as the formwork for this filling concrete and forms the outer surface of the pillar. The outer shape 2 has a finished surface of a pillar. The main rebar 4 and the hoop rebar 5 are 0.8% or more and 0.2% or more of the column total cross section, respectively. By designing, the upper and lower joints are provided with the necessary means, and the filling concrete is poured. The pillar can be constructed by itself.

FIG. 2 shows an example of bar arrangement when constructing the pillars 1a and 1b of the embodiment. The pillar 1a on the lower floor is the foundation 1
It is externally fitted to a reinforcing bar 12 that has risen from 1, and the reinforcing bar 12 and the main reinforcing bar 4 are connected by a lap joint method. The main rebar 4 is located above the upper end of the column 1a, and the beam 2
The main reinforcing bar extension 8 extending to the portion 1 is provided, and the lap joint reinforcing bar 25 is arranged as a lap joint between the main reinforcing bar extension 8 and the lower end of the upper column 1b. The beam 21
Are connected by the reinforcing bars 23 and 24 through the connecting portions of the upper and lower columns 1a and 1b. In this way, the upper and lower pillars 1a,
1b and the left and right beams 21 are mechanically and firmly connected. FIG. 5: is a perspective view which shows the process of arranging the beam connecting reinforcement 23 on the upper part of the pillar 1a of the lower floor.

FIG. 3 shows an example in which the main reinforcing bar extension 9 above the main reinforcing bar 4 of the pillar 1a on the lower floor extends to the lower end of the pillar 1b on the upper floor. It does not require a separate lap joint reinforcing bar for connecting 1b. Others are the same as in FIG. FIG. 4 shows an example of a pillar in which the main reinforcing bars 4 of the pillar 1a on the lower floor do not extend upward. in this case,
Lap joint reinforcing bar 25 for connecting main reinforcing bars of upper and lower columns 1a, 1b
Is used. Since the pillar 1a having such a structure has no extending reinforcing bar, it is easy to manufacture, handle and construct.

In FIGS. 2, 3 and 4, the hoop muscle 5
The part where is drawn closely is the part where the joint rebar is placed,
This is a part provided with a reinforcing bar with nails described below. The connection of the lap joints of the columns of the embodiment will be described. Figure 7
Is the main rebar 4, the basic rebar 12 (see FIGS. 2, 3 and 4), the main rebar extension 9 (FIG. 3) or the lap joint rebar 25 (FIG. 2,
Fig. 4) schematically shows the mechanical behavior with As shown in FIG. 7, when the main reinforcing bar 4 and the joint reinforcing bar are pulled in the direction of arrow 15, a compressive force 17 acts on the concrete, and the horizontal component force separates the reinforcing bar in the separating direction 16. In order to prevent this, in addition to the hoop muscle 5, a claw reinforcing bar 13 is provided. FIG. 6 is a partial cross-sectional view of the pillar 1 showing the reinforcing bar 13 with a claw. In FIG. 6, since the basic reinforcing bar 12 (or the main reinforcing bar extension 9 or the lap joint reinforcing bar 25) having a hatched circular cross section and the main reinforcing bar 4 shown by a white circle are coupled, the reinforcing bar 13 with a claw (hatched. Surrounding the main rebar 4 is provided so as to project into the hollow portion 3 of the pillar 1. In this state, when the filling concrete is poured into the hollow portion 3, the main rebars shown by white circles and the joint rebars with hatching are joined so as not to be mechanically separated.

In the pillar 1 of the embodiment, the length of the precast pillar 1 is formed to a length of 2.4 to 2.5 m according to the height of the highest floor of the building, and the cutting allowance is 0.3 to 0. In anticipation of 4 m, the reinforcing bar 13 with nails was arranged in the portion of the length added by that amount. The pillar 1 of the embodiment can be easily manufactured by centrifugal molding, and excellent concrete having a solid outer surface can be easily manufactured.

Next, with reference to FIGS. 8 to 13, a method of constructing a pillar of the present invention will be described. In FIG. 8, the pillar 1a on the lower floor
The beam 21a and the slab 26 were constructed. The lap joint reinforcing bar 25 projects above the column 1a (the column on the left in FIG. 8). In order to construct a pillar on this floor, an additional inner main reinforcing bar 31 is carried by a hanger 32 and moved as indicated by an arrow 33 to be joined by a lap joint reinforcing bar 25 and a welded joint 34 to form a main reinforcing bar 31.
Stands upright (the right column facing in FIG. 8). As shown in FIG. 9, the precast pillar 1b of the embodiment, which also serves as the formwork, is suspended from above the erected main rebar 31 by the hoisting tool 32, and the inner main rebar 3
It is fitted on 1. The column on the right side of FIG. 9 shows this state. FIG. 10 shows a step of placing the form 27 of the beam 21b on the upper floor on the column 1b which also serves as the form. Pillar 1b is a support metal 35
Have been stopped by. Further, the main reinforcing bar 9 extending above the pillar 1b is attached along the inner main reinforcing bar 31. The pillar 1b has main rebars and hoops built in its wall. The beam formwork 27 is lowered as indicated by arrow 36. Figure 10
A beam formwork 27 is already placed on the left side of the right column facing to.

FIG. 11 shows the step of placing the precast slab 41 on the edge of the beam frame 27. FIG. 12 shows a state where the reinforcements 42 on the upper surface of the beam and the slab 41 are assembled. FIG. 13 shows a concrete transport pipe 44 on the slab 41.
The process of placing the concrete 43 that has been carried in is shown. In FIG. 13, all the description of the bar arrangement 42 shown in FIG. 12 is omitted. The concrete 43 is applied to the inside of the hollow portion 3 of the pillar 1b, the inside of the form frame 27 of the beam, and the upper surface of the slab 41. After hardening the concrete, the form of the beam is removed, the construction of this floor is completed, the state shown in FIG. 8 is reached, and the construction of the upper floor is performed. According to the method of the embodiment, the pillars, the beams, and the slabs can be quickly constructed without using the pillar formwork.

[0024]

According to the present invention, all columns can be constructed with the same precast column, and the management is easy and the cost is low. In addition, this precast column that also serves as a form can be manufactured from high-quality concrete by centrifugal molding, and a column with an excellent finished surface can be easily constructed. It does not require a pillar formwork, has high strength, is lightweight, is easy to handle, and facilitates construction. In addition, the lap joint is devised so that connection is easy.

[Brief description of drawings]

1A and 1B are a horizontal cross-sectional view and a vertical cross-sectional view, respectively, showing a precast column that also serves as a mold of an example.

FIG. 2 is a construction explanatory view of a precast column that also serves as a formwork of the embodiment.

FIG. 3 is a construction explanatory view of a precast column that also serves as a formwork of the embodiment.

FIG. 4 is a construction explanatory view of a precast column which also serves as a formwork of the embodiment.

FIG. 5 is a construction explanatory view of a stigma of a precast column that also serves as a formwork of the example.

FIG. 6 is a lateral cross-sectional view of a precast column portion which also serves as a formwork of the embodiment.

FIG. 7 is an explanatory diagram of mechanical behavior of a lap joint reinforcing bar.

FIG. 8 is a process drawing of a precast column that also serves as a formwork of the example.

FIG. 9 is a process drawing of a precast column that also serves as a formwork of the example.

FIG. 10 is a process drawing of a precast column that also serves as a formwork of the example.

FIG. 11 is a process drawing of a precast column that also serves as a formwork of the example.

FIG. 12 is a construction process diagram of a precast column that also serves as a formwork of the example.

FIG. 13 is a process drawing of a precast column that also serves as a formwork of the example.

[Explanation of symbols]

1, 1a, 1b Column 2 Outer shape 3 Hollow part 4 Main rebar 5 Hoop rebar 6 Concrete 7 Inner surface 8 Main rebar extension 9 Main rebar extension 11 Foundation 12 Basic rebar 13 Claw bar 14 Internal main rebar 15 Tensile force 16 Separation direction 17 Compressive Force 21 Beam 22 Beam Main Reinforcement 23 Connecting Reinforcing Bar 24 Lap Joint Reinforcing Bar 25 Lap Joint Reinforcing Bar 26 Slab 31 Internal Main Reinforcing Bar 32 Lifting Device 33 Arrow 34 Weld Joint 35 Supporting Hardware 36 Arrow 41 Slab 42 Reinforcement 43 Concrete 44 Concrete Transport Pipe

Claims (8)

[Claims] 1. A formwork having a finished column outer shape, a main rebar and a hoop rebar being contained in a concrete wall, and a hollow column body having a vertically penetrating hollow portion for filling concrete. Combined precast pillar. 2. A precast also used as a formwork according to claim 1, which has a main rebar amount of 0.8% or more of the entire cross section and a hoop reinforcing amount of 0.2% or more of the entire cross section. Pillar. 3. A structure in which (A) main rebar extends from the upper end of the column into the beam-column joint, (B) a main rebar extends from the upper end of the column into the column base of the upper floor, and (C) The precast column also used as a formwork according to claim 1, wherein the main reinforcing bar is one type of structure selected from the group of structures that do not extend from the upper end of the column. 4. A plurality of claw reinforcing bars surrounding a main reinforcing bar in a concrete wall and projecting ends in a hollow portion are arranged near the lower end of the pillar or near the lower end and the upper end along the axial direction of the pillar. The precast pillar that also serves as the formwork according to claim 1. 5. The length of the precast pillar is adjusted to the highest floor height of the building, and the pillar length of the portion where the reinforcing bar with claws is arranged is a length including a cutting allowance. The precast pillar that also serves as the formwork according to Item 4. 6. The precast column which also serves as a formwork, according to claim 1, which is made of centrifugally molded concrete. 7. When constructing a concrete column, the precast column also used as the formwork according to claim 1 is erected so that the lower end of the precast column is externally fitted to the foundation at the column standing position or a lap joint vertical rebar protruding on the beam. Then, place the precast upper floor beam or upper floor beam formwork on the stake and arrange the beam column lap joint reinforcement, and place the floor half precast slab or slab formwork on the upper floor slab position. A method for constructing a precast column that also serves as a formwork, characterized in that after arranging, the hollow-filled concrete, beam, and floor concrete of the precast column that also serves as the formwork are placed. 8. The precast column that also serves as the formwork according to claim 7, wherein the precast column that also serves as the formwork is externally fitted to the inner main rebar after the required inner main rebar and hoop reinforcement have been assembled. Construction method.