JPH04221610A - Manufacture of centrifugal force molded steel pipe - Google Patents

Abstract

PURPOSE:To manufacture a steel pipe concrete pillar which is a composite pillar of a steel pipe and concrete to be placed within the steel pipe and has a stabilized quality and high rigidity. CONSTITUTION:After centrifugal compaction is performed by casting the first layer concrete into a steel pipe by making the steel pipe into an outer shell, slurry within the first hollow part to be formed within the first layer concrete layer is removed and the first curing is performed. Then after the centrifugal compaction is performed again by casting the second layer concrete into the foregoing first hollow part, the second curing is performed by removing the slurry within the second hollow part to be formed within the second layer of a concrete layer. Furthermore, a plurality of concrete layers are formed at need, a hollow part formed finally is filled with mortar and shaped into a solid section, through those of which a manufacture of a centrifugal force molded steel pipe concrete pillar is provided.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention relates to a method for manufacturing centrifugally formed steel pipe concrete columns, and in particular to columns used in high-rise buildings etc. The present invention relates to a method for manufacturing steel pipe concrete columns made of high-strength concrete formed by

0002

[Prior art] As a conventional steel pipe concrete column,
Composite columns are known in which the outer shell is a steel pipe and concrete is poured inside. This composite column is formed by erecting and welding steel pipes on site, and then pouring concrete into the steel pipes.

0003

[Problems to be Solved by the Invention] When forming the above-mentioned conventional type of cast-in-place concrete composite column, it is necessary to cure the concrete cast on the site. In addition, there are quality problems with this kind of cast-in-place concrete,
High strength concrete cannot be obtained. Furthermore, when attempting to integrally mold a diaphragm that connects beam members by protruding inside the steel pipe, there are two methods: the tremie tube method, in which the diaphragm is injected from above, and the press-fit method, in which it is injected from the bottom. As a result, so-called voids (missing cross sections) occur on the lower surface near the joint between the steel pipe and the diaphragm, and it is impossible to expect a highly rigid composite column to be formed.

[0004] Therefore, a technical problem arises that must be solved in order to manufacture a steel pipe concrete column with stable quality and high rigidity, which is a composite column of a steel pipe and concrete placed inside the steel pipe. Therefore, the present invention aims to solve this problem.

[0005]

[Means for Solving the Problems] This invention was proposed to achieve the above object, and involves making a steel pipe an outer shell, pouring a first layer of concrete into the steel pipe, and subjecting it to centrifugal compaction. After that, the slurry in the first hollow part formed inside the first concrete layer is removed and first curing is performed, and then the second layer of concrete is poured into the first hollow part. After injecting and performing centrifugal compaction again, the slurry in the second hollow part formed inside the second concrete layer is removed and second curing is performed, and further, if necessary, A method for manufacturing a centrifugally formed steel pipe concrete column, characterized in that a plurality of concrete layers are formed in a similar manner, and the finally formed hollow part is filled with mortar to form a solid cross section, and Formed by centrifugal compaction in a steel pipe, characterized in that the internal hollow part of the concrete layer formed by compaction is not filled with the mortar, and the hollow part is formed to the minimum necessary size. The purpose of this study is to provide a method for manufacturing steel pipe concrete columns.

[0006]

[Operation] This invention forms the first layer of concrete within the steel pipe of the outer shell by centrifugal compaction. At this time, the first concrete layer is tightly compacted to the inner surface of the steel pipe and sufficiently compacted to an appropriate thickness, and a cylindrical first hollow part is formed in the center thereof. Thus, slurry is generated on the inner surface of this cylindrical first hollow part during the centrifugal compaction operation. Therefore, the slurry is caused to flow out by means such as tilting the formwork. Thereafter, by performing primary curing, early compaction of the first concrete layer is assisted.

Next, a second layer of concrete is poured into the first hollow part and centrifugally compacted. In this case, the slurry is discharged, so that the second layer of centrifugally compacted concrete is formed integrally with the inner surface of the first concrete layer. A cylindrical second hollow part is formed in the center thereof. Slurry generated during the centrifugal compaction operation is adhered to the inner surface of this cylindrical second hollow part. Therefore, the slurry is caused to flow out by means such as tilting the formwork. Thereafter, secondary curing is performed to assist in early compaction of the second concrete layer. Furthermore, if necessary, layers of concrete are formed by centrifugal compaction using the same method for the third and subsequent layers, and the final state is that the minimum required hollow space is drilled vertically in the center. It is formed as follows. Therefore, the steel pipe concrete column according to claim 2 is manufactured by letting the finally formed slurry in the hollow part flow out as described above, or by removing the slurry from the mold without letting it flow out.

Furthermore, the finally formed hollow portion of the demolded steel pipe concrete column is filled with high-strength mortar to form a solid cross section, thereby forming a steel pipe concrete column with high rigidity. During the above manufacturing process, even if the diaphragm connecting the beam member is fixed to the steel pipe, since the concrete is formed by centrifugal compaction, the lower part of the diaphragm is There is no occurrence of voids (defected cross-sections) in the structure, which degrades quality and rigidity.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. In the figure, 1 is a steel pipe, and a square or cylindrical shape is used. 2, 2 are diaphragms that connect the beam members, and have circular holes 2a, 2a in the center. The diaphragms 2, 2 are fixed to the steel pipe 1, and a portion thereof protrudes outward from the steel pipe 1.

In FIG. 1, the steel pipe 1 is a formwork (not shown).
inserted into. The formwork may be a general formwork used when forming precast concrete columns. however,
A spacer (not shown) is interposed in the formwork so that the protruding portions of the diaphragms 2, 2 protruding from the outside of the steel pipe 1 are not pressed against the inner surface of the formwork. It goes without saying that the structure is such that the concrete poured into the steel pipe 1 is centrifugally compacted by being rotated by a rotation mechanism (not shown). Therefore, a first layer of concrete is poured into the steel pipe 1 and centrifugal compaction is performed. In such a case, the concrete firmly adheres to the inner surface of the steel pipe 1, has a certain thickness, is centrifugally compacted, and
A concrete layer 3 is formed. Thus, a first hollow portion 3a having a diameter t is formed inside the first concrete layer 3. A first slurry 4 is generated on the inner surface of the first concrete layer 3 during centrifugal compaction of the concrete.

Therefore, as shown in FIG. 2, since the first slurry 4 has no strength at all as concrete, it is removed. As a method for removing it, for example, by tilting the mold, the first slurry 4 flows out naturally. Thereafter, primary curing is performed at normal temperature and pressure to assist early compaction of the first concrete layer 3. Next, after the first slurry 4 is removed and first curing is performed, concrete is poured into the first hollow part 3a and a second concrete layer 5 is formed, as shown in FIG. form. In this case, since the first slurry 4 has already been removed from the inner surface of the first concrete layer 3, the second slurry 4, which has been injected into the first hollow part 3a and centrifugally compacted, The concrete layer 5 has a predetermined thickness and firmly adheres to the inner surface of the first concrete layer 3, and is integrated with the first concrete layer 3 to have great rigidity. has.

Further, the second concrete layer 5 also has a second hollow part 5a having a diameter t due to its centrifugal compaction action, and the inner surface of the second concrete layer 5 also has the above-mentioned hollow part 5a. The second slurry 6 is generated as the slurry is heated. Therefore, Figure 4
As shown in FIG. 2, the second slurry 6 is removed by flowing out to the outside by means such as tilting the formwork, and then second curing is performed again at normal temperature and pressure to form the second concrete layer. 5
to support early compaction.

Next, a third layer of concrete is poured into the second hollow portion 5a and centrifugally compacted to form a third concrete layer 7. Since the third concrete layer 7 does not include the second slurry 6, it tightly adheres to the inner surface of the second concrete layer 5 and has great rigidity. It turns out. Therefore, inside the third concrete layer 7, a third hollow part 7a having a diameter of t2 is formed by centrifugal compaction.
This third hollow portion 7a is made to have the minimum necessary size during centrifugal compaction. However, as described above, the third slurry 8 is also generated on the inner surface of the third concrete layer 7, but as shown in FIG. After the second curing is performed, the mold is demolded and, if necessary, autoclave curing is performed to constitute the invention according to claim 2.

Furthermore, the invention according to claim 1 provides that, as shown in FIG. 6, after the third slurry 8 is removed, a second curing is performed, the mold is demolded, and the third slurry 8 is removed. The third hollow portion 7a may be filled with high-strength mortar 9 to form a solid cross section as shown in FIG. 7, and may be cured in an autoclave if necessary. In this way, a steel pipe concrete column with even greater rigidity is produced.

[0015] This invention can be modified in various ways without departing from the spirit of the invention, and it goes without saying that this invention extends to such modifications.

[0016]

[Effects of the Invention] Since the present invention relates to the method detailed in the above-mentioned embodiment, the concrete layer cast inside the steel pipe is cast by centrifugal compaction, so that it is integrated with the steel pipe. The rigidity is extremely high, and not only is there no slurry interposed between each concrete layer, but there is also no void under the diaphragm of the member that connects the beam members, so the whole is integrated and has extremely high quality. A large concrete column with stable rigidity can be obtained. Therefore, it can be used for column members of high-rise buildings, etc.

[0017] As described above, since the inside of the steel pipe is integrally filled with high-strength concrete and high-strength mortar, it is possible to have a small diameter cross section, which is extremely economical. Therefore, the present invention constitutes an invention that brings about various great effects, such as making it possible to make the indoor space of a building larger.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway vertical sectional view showing the manufacturing process of a steel pipe concrete column.

FIG. 2 is a partially cutaway vertical sectional view showing the manufacturing process of a steel pipe concrete column.

FIG. 3 is a partially cutaway vertical cross-sectional view showing the manufacturing process of the steel pipe concrete column.

FIG. 4 is a partially cutaway vertical sectional view showing the manufacturing process of the steel pipe concrete column.

FIG. 5 is a partially cutaway longitudinal sectional view showing the manufacturing process of the steel pipe concrete column.

FIG. 6 is a partially cutaway vertical sectional view showing the manufacturing process of the steel pipe concrete column.

FIG. 7 is a partially cutaway vertical sectional view showing the manufacturing process of the steel pipe concrete column.

[Explanation of symbols]

1 Steel pipe 2 Diaphragm 3. 1st layer concrete layer 3a First hollow part 4 First slurry 5 Second concrete layer 5a Second hollow part 6 Second slurry 7 3rd layer concrete layer 7a Third hollow part 8 Third slurry 9 High strength mortar

Claims (2)

[Claims] Claim 1: A steel pipe is used as an outer shell, and after pouring a first layer of concrete into the steel pipe and performing centrifugal compaction,
First curing is performed by removing the slurry in the first hollow part formed inside the concrete layer, and then a second layer of concrete is poured into the first hollow part and centrifugally compacted again. After hardening, the slurry in the second hollow part formed inside the second concrete layer is removed and the second concrete layer is solidified.
Centrifugal force is characterized by curing, then forming multiple concrete layers using the same method as necessary, and finally filling the formed hollow with mortar to form a solid cross section. Manufacturing method for formed steel pipe concrete columns. 2. A hollow part of the concrete layer formed by centrifugal compaction is not filled with the mortar, and the hollow part is formed to the minimum necessary size. 1. The method for manufacturing a centrifugally formed steel pipe concrete column.