JP2002283335A - Manufacturing method of shell precast post - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a shell precast post which enables reduction of the cost of a form and that of equipment for accelerated cure. SOLUTION: An elastically deformable tube member 16 is used as an inner form. A pressure gas is injected into the tube member 16 and expanded to make the tube member 16 project partially from gaps between hoop bars 13. Thereby a large number of indentations are formed on the outer peripheral surface of the tube member 16 and, in this state, concrete 11 is placed between the tube member 16 and an outer form 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a shell precast column.

[0002]

2. Description of the Related Art When manufacturing an outer shell precast column,
First, pre-assembly the hoop muscle (ligament), assemble the inner and outer forms on the inner and outer peripheries of this pre-assembled hoop muscle, drive the cleat between the inner and outer forms, cure, and then remove the inner and outer forms. It is common to do. In the past, steel forms were used for both the inner and outer forms.

[0003] On the other hand, when an outer shell precast column is installed on site and then concrete is post-punched into its internal space,
It is necessary to increase the bonding strength between the concrete of the outer shell precast column and the post-cast concrete.

For this reason, conventionally, a cotter mold having a large number of irregularities is used as a part of an inner mold,
Many irregularities were formed on the inner peripheral surface of the concrete, and the irregularities ensured the adhesive strength to the post-cast concrete.

[0005]

However, in the conventional method, since an expensive steel mold is used as the inner and outer molds, there is a problem that the cost of the mold is increased. Further, since a cotter form is required, there is a problem that the material cost and the mounting cost to the inner form are required.

Further, in order to shorten the manufacturing process of the precast concrete column, if the mold is removed immediately on the same day, it is necessary to perform sheet curing and accelerated curing. .

An object of the present invention is to solve such a problem, and provides a method for manufacturing a shell precast column capable of reducing the cost of a formwork and the cost of an accelerated curing facility. This is a technical issue.

[0008]

SUMMARY OF THE INVENTION The present invention is a method for manufacturing a shell precast column, and is constituted as follows in order to solve the above-mentioned technical problem. That is, the outer shell precast column of the present invention pre-assembles the hoop reinforcement to be incorporated, assembles an inner mold and an outer mold around the inner and outer peripheries of the pre-assembled hoop reinforcement, and forms the inner mold and the outer mold. During the casting of concrete, after curing of the concrete, in the method of manufacturing the outer shell precast column to release the inner and outer form, using an elastically deformable tube member as the inner form,
A number of irregularities are formed on the outer peripheral surface of the tube member by injecting a pressurized gas into the tube member to expand the tube member and projecting a part of the tube member from the gap between the hoop streaks to the outer mold side. In this state, concrete is poured between the tube member and the outer formwork.

Further, the present invention is characterized in that after the concrete is cast, a warm air of a predetermined temperature is injected into the tube member to cure the concrete.

According to the present invention, since the inner mold is a tube which is elastically deformable, the cost is lower than that of the steel mold. Also,
Since the concrete is cast in a state where a large number of irregularities are formed on the outer peripheral surface of the tube member, a large number of irregularities are formed on the inner peripheral surface of the concrete, and the irregularities can increase the bonding strength with the post-cast concrete.

Furthermore, during curing of concrete, accelerated curing can be performed only by injecting hot air into the tube member at a predetermined temperature, so that the accelerated curing equipment can be simply constituted by a heater and a blower.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a method for manufacturing a shell precast column according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing an outer shell precast column 1 manufactured according to the present invention, and FIG. 2 is a transverse sectional view of the outer shell precast column 1. As shown in FIG. 1 and FIG. 2, the outer shell precast column 1 includes a tubular concrete 11 having a rectangular cross section, and a plurality of column reinforcements 12, 12. Pillar 1
Numerous hoop bars 1 arranged on the outer peripheral side of 2, 12, ...
3, 13,....

On the inner peripheral surface of the concrete 11, a large number of irregularities 14, 14... Are provided continuously over the entire periphery. These irregularities 14, 14,...
Are formed at the same pitch as 3, 13,.

Next, a method of manufacturing the outer shell precast column 1 will be described. In manufacturing the outer shell precast column 1, first, as shown in FIG.
. And the hoops 13, 13,...

Next, as shown in FIG. 4, a steel outer frame 15 is assembled on the outer peripheral side of the pre-assembled column bars 12, 12,... And the hoop bars 13, 13,. Subsequently, FIG.
, And the hoop muscle 1
An air tube 16 having a predetermined size is inserted inside 3, 13,....

The air tube 16 is made of a material having a certain degree of heat resistance (approximately 80 degrees), such as rubber or vinylon fiber, an air fence often used as a material for a sunny hose, a beam, or a concrete stop frame for casting on site. The opening 16a is connected to a blower 17 capable of pressure control. The blower 17 is provided with a heater 18 whose temperature can be controlled, and can send out hot air having a predetermined pressure and a predetermined temperature. Then, when air having a predetermined pressure is injected from the blower 17 into the air tube 16, the air tube 16 becomes
It expands to a diameter slightly larger than the diameter of 3 ....

Next, as shown in FIG. 6, a pressure air 1 of a normal temperature and a predetermined pressure is introduced into the air tube 16 from the blower 17.
Inject 9. Then, as shown in FIG. 7, the air tube 16 expands and all the hoops 13, 13,...
And the hoops 13, 13, ...
-A part of the air tube 16 protrudes from the gap between the outer mold frame 15 side. Thereby, on the outer peripheral surface of the air tube 16, at the same pitch as the hoops 13, 13,.
.. Are formed.

In this state, next, as shown in FIG.
Is installed. After the placement of the concrete 11 is completed, as shown in FIG. 9, a hot air 21 having a predetermined temperature higher than the surrounding air temperature is injected into the air tube 16 from the blower 17 and accelerated curing. Then, after the accelerated curing of the concrete 11 is completed, the outer mold 15 and the air tube 16 are removed. Thereby, the outer shell precast column 1 of FIG. 1 is completed.

As described above, the method for manufacturing the outer shell precast column of the present invention uses the elastically deformable air tube 16 as the inner mold, so that the method is compared with the conventional case using a steel mold. Formwork costs can be reduced.

The concrete 1 is formed with a large number of irregularities 20, 20... Formed on the outer peripheral surface of the air tube 16.
1 can be formed on the inner peripheral surface of the concrete 11 to form a large number of irregularities 14, 14...
4, 14,..., It is possible to ensure the strength of adhesion to post-cast concrete. Therefore, since it is not necessary to use the conventional cotter formwork, the cost can be reduced.

Furthermore, since the accelerated curing of the concrete 11 can be performed only by injecting the hot air 21 of a predetermined temperature into the air tube 16, the accelerated curing equipment is provided with the blower 17 and the heater 1
8, the configuration can be simplified, and the equipment cost can be reduced.

Further, the accelerated curing of the concrete 11 makes it possible to remove the mold on the same day.
Manufacturing process control becomes easy. Furthermore, concrete 11
Promotes curing, the concrete structure becomes dense (the pore volume is reduced) and the watertightness is improved, so that the quality of the concrete 11 is easily ensured.

[0024]

As described above, according to the present invention,
Since the inner mold is an elastically deformable tube member, it is less expensive than a steel mold. In addition, by casting concrete with a large number of irregularities formed on the outer peripheral surface of the tube member, a large number of irregularities are formed on the inner peripheral surface of the concrete, so that the post-cast concrete can be used without using a cotter formwork. Adhesion strength can be ensured. Therefore, the mold cost can be reduced.

Furthermore, during curing of concrete, accelerated curing can be performed only by injecting hot air at a predetermined temperature into the tube member, so that the accelerated curing equipment can be easily constituted by a heater and a blower. Thereby, the cost of the equipment for promoting curing can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an outer shell precast column to which an outer shell precast column manufacturing method according to the present invention is applied.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view showing a pre-assembled state of a reinforcing bar of the outer shell precast column according to the present invention.

FIG. 4 is a perspective view showing a reinforcing bar and an outer formwork of the outer shell precast column according to the present invention.

FIG. 5 is a perspective view showing an inserted state of a tube member in the method for manufacturing an outer shell precast column according to the present invention.

FIG. 6 is a perspective view showing a state in which room-temperature air is injected into a tube member in the method for manufacturing an outer shell precast column according to the present invention.

FIG. 7 is a sectional view showing irregularities formed on the outer peripheral surface of the tube member according to the present invention.

FIG. 8 is a perspective view showing a concrete casting state in the method for manufacturing an outer shell precast column according to the present invention.

FIG. 9 is a diagram showing accelerated curing in the method for producing a shell precast column according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer shell precast column 11 Concrete 13 Hoop bar 14 Irregularity 15 Outer frame 16 Air tube (Inner type)

Claims (2)

[Claims] 1. A hoop reinforcement to be built into concrete is pre-assembled, and an inner mold and an outer mold are arranged on the inner and outer peripheries of the pre-assembled hoop, and between the inner and outer molds. A method of manufacturing an outer shell precast column in which concrete is cast, the concrete is cured, and the inner and outer forms are removed from the form, wherein an elastically deformable tube member is used as the inner form, and a pressurized gas is introduced into the tube member. The tube member is formed by injecting and expanding a portion of the tube member so as to protrude from the gap between the hoop streaks to the outer mold frame side, thereby forming a large number of irregularities on the outer peripheral surface of the tube member. And casting the concrete between the outer formwork and the outer formwork. 2. A method for manufacturing an outer shell precast column, wherein after the concrete is cast, a hot air at a predetermined temperature is injected into the tube member to cure the concrete.