JP2575787Y2 - Precast concrete members for concrete pillar construction - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention is used for forming concrete columns during construction of concrete columns, and after being cast, forms concrete columns integrally with cast concrete. It relates to a precast concrete member.

[0002]

2. Description of the Related Art Conventionally, as a means of constructing a concrete column, a method of completely constructing a site or using a precast column has been generally used. In the case of complete on-site construction, a formwork is assembled so as to surround the column reinforcing bars already assembled at the site where the columns are to be constructed, concrete is poured into the formwork, and after the concrete is hardened, the formwork is installed. The concrete columns will be constructed by removing them. In the case of the precast pillar, a concrete pillar having a whole cross section is manufactured in advance at a factory, and the concrete pillar is erected at a predetermined position on the site.

[0003] In the above-mentioned conventional means, the one constructed entirely on site requires time and effort to install and dismantle the formwork, while the one constructed using precast pillars has a large weight of members and is difficult to handle such as transportation and installation. was there. Further, in particular, in the case of a completely constructed on-site construction, recently, there has been seen an example which is cited as one of the problems of the earth resources because the weir plate used as the formwork is made of wood.

For this reason, in recent years, a precast concrete member formed into a tubular shape has been used as a so-called formwork as a formwork for concrete casting, and concrete has been cast inside the precast concrete member and used as a formwork. A construction method for configuring this precast concrete member as a final pillar has also been developed and adopted.

FIGS. 7 to 10 show an example in which a concrete column is constructed by the above-mentioned method. FIG. 7 shows a state where the column reinforcing bar 2 has already been assembled at the place where the column on the foundation slab 1 is to be constructed. After this state, the above-described precast concrete member 3 is suspended from above the column reinforcing bar 2 as shown in FIG. Next, as shown in FIG. 9, the incorporated precast concrete member (hereinafter, abbreviated as “precast member”) 3
Adjust the building. Reference numeral 6 in the figure denotes an adjusting member (such as a steel rod with a turnbuckle) for adjusting the installation.
Then, as shown in FIG.
After the necessary members such as the beam reinforcing bar 7 are incorporated into the upper end of the precast member 3, concrete (not shown) may be poured into the inside of the precast member 3. When the poured concrete hardens, the concrete column 8 is completed. The precast member 3
Is usually set to the height of the first floor in this way.
In other words, this method can be said to be a type of half precast method applied to pillars.

[0006]

As described above, by constructing a concrete column using the precast member 3 as described above, it is expected that both the disadvantages in the complete on-site construction and the defects in the precast columns can be solved at once. However, the conventional precast member 3 still has the following disadvantages to be solved.

[0007] The precast member 3 is of a type in which a column reinforcing bar is previously embedded in the concrete constituting the precast member 3 and a type which does not have a column reinforcing bar (however, for preventing cracks). Wire mesh). Of the two types, the latter type has the advantages of being lighter and easier to manufacture than the former type. However, in the latter type, the conventional one is a precast member 3 whose one of its greatest advantages is that it has a large thickness and is lightweight as a formwork in order to secure strength.
However, there was a drawback that the superiority of the system could not be fully exhibited.

Further, in the conventional precast member 3, as shown in FIG. 11 as an example, four corners 4a of the inner surface 4 are formed in a substantially right angle. For this reason, when concrete is cast inside at the site, the concrete is not sufficiently filled in the corners and voids are formed, thereby, for example,
There was a fear that the precast member 3 might have a problem such as cracking.

The present invention has been made in view of the above-mentioned circumstances, and provides a precast concrete member for constructing a concrete column which eliminates the above-mentioned disadvantages, is lightweight and strong, and can realize complete filling of cast-in-place concrete. The purpose is to do.

[0010]

According to the first aspect of the present invention,
A precast for concrete column construction, which has a cylindrical shape of a predetermined length with a substantially rectangular cross section as a whole, and is formed into concrete columns integrally with the cast concrete by being poured into the concrete at the column construction site. In the concrete member, the inner surface of the precast concrete member for constructing the concrete pillar projects toward the center at the center along the side direction of each side forming the rectangular cross section.
A thick portion having a predetermined width functioning as a reinforcing rib for reinforcing each side is continuously formed in the longitudinal direction of the precast concrete member itself for constructing the concrete pillar, and each side portion excluding the thick portion is formed. The thickness of the inner surface is set to 3 to 6% of the outer dimension, and at least four corners of the inner surface are formed as curved or chamfered surfaces.

According to a second aspect of the present invention, in the precast concrete member for constructing a concrete column according to the first aspect, the width of the thick portion is set to 12 to 25 with respect to the outer dimension.
% Is set.

According to a third aspect of the present invention, in the precast concrete member for constructing a concrete pillar according to the second aspect, the thickness of the thick portion is 120 to 150 with respect to the thickness of a side portion other than the thick portion. % Is set.

[0013]

In the precast concrete member for constructing a concrete pillar according to the first aspect, the thick portion formed at the center of each side of the rectangular precast concrete member has
It functions as a reinforcing rib to reinforce each side, thereby realizing a reduction in the thickness of each side. Further, since the four corners of the inner surface are curved or chamfered, when the concrete is poured into the inside of the precast concrete member, the cast concrete is completely filled up to the corners.

[0014] In the precast concrete member for constructing a concrete column according to claim 2 or 3, the most rational structure can be achieved both in reducing the thickness of each side portion and in securing the strength of each reduced side portion. To achieve.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are a front view and a side view, respectively, showing an embodiment of the present invention. As shown in the drawing, the precast member 10 has a cylindrical shape having a substantially constant thickness and a substantially square cross section as a whole. FIG. 3 shows an enlarged cross section of the precast member 10. Reference numeral 14 in FIG. 3 denotes a wire mesh for preventing cracking. As can be seen from FIG.
In the inner surface 11 of the zero, the center of each side forming a substantially square shape protrudes toward the center of the substantially square formed by the inner surface 11. Thereby, the precast member 10
Reinforcement ribs for each side at the center of each side
A thick part 12 having a certain width and functioning as a part is formed.

The thickness t of each side of the rectangular precast member 10 is the outer side dimension a of the precast member 10.
Is 3 to 6%, and is set to be thin.
As an example, the outer dimension a is 1000 mm, and the thickness t of the side excluding the thick portion 12 is 40 mm (4% of the outer dimension a). The dimensions of the thick portion 12 are such that the width b is 196 mm and the thickness t 'is 50 mm.

Here, as described above, the precast member 1
The reason why the thickness t of 0 is set to the size of 3 to 6% with respect to the outer dimension a is that if the thickness is less than 3%, the strength as a form in which concrete is cast inside may be insufficient. On the other hand, if it exceeds 6%, the thickness becomes unnecessarily high in strength, the material cost increases, the weight increases, and the work at the time of transportation and construction becomes inefficient. Because.

Further, the precast member 10 according to the present invention.
In the above, the width b of the thick portion 12 is 12 to 25% of the outer side dimension a, and the thickness t 'of the thick portion is 120 to 150% of the thickness t. It is set to be the dimensions. The grounds for this will be described below. The thick part 12 is formed at the center of each side part, and reinforces each thin side part. Therefore, when the width b and the thickness t 'of the thick portion 12 are smaller than the above-mentioned set values, there is a possibility that the reinforcing effect of the thick portion 12 cannot be expected. Also,
There is also an adverse effect such that it becomes difficult to fill the concrete material. On the other hand, when the width b and the thickness t ′ exceed the above-mentioned set values, the reinforcing portion has an unnecessarily large size, and the significance of setting the thickness t of each side portion small as described above may be lost. Is caused.

As shown in FIG. 3, four corners 11a of the inner surface 11 of the precast member 10 are formed as curved surfaces, that is, so-called R surfaces. On the other hand, four corners 13a of the outer surface 13 of the precast member 10 are chamfered.

The precast member 10 as described above is manufactured by a well-known centrifugal molding method for concrete, like the conventional precast member according to the present invention. The method of using the precast member 10 may be the same as the conventional method. For example, the method may be performed as shown in FIGS. 7 to 10 as an example.

According to the precast member 10, first, since it is thin, it is extremely light, and handling such as transporting or assembling on site is very light, and the working efficiency can be improved. Also, material costs are saved because no useless materials are used. In addition, by forming a thick portion 12 projecting inward at the center of each side forming a rectangle as a whole, each thin side is effectively reinforced, thereby realizing a thin product as a whole. That is. Further, since each corner 11a of the inner surface 11 is formed on the R-plane, when concrete is poured into the inside of the precast member 10 at the site, the cast concrete is placed at the corner 1a.
It becomes completely filled up to 1a. Therefore, it is possible to reliably prevent the formation of a gap between the precast member 10 and the cast concrete, and to prevent the adverse effects that may occur when the gap exists, for example, the occurrence of cracks and the like in the precast member 10. can do. In addition, in the precast member 10, since each corner 13a of the outer surface 13 is chamfered and formed, the corner 13a contacts the obstacle or the object collides during handling.
3a can be prevented from being easily chipped, and the handling is safe.

FIGS. 4 to 6 show other embodiments of the present invention, each showing the shape of a corner of a precast member. In FIG. 4, similarly to the corner 13 a of the outer surface 13, the corner 11 a of the inner surface 11 is also formed as a chamfered surface. FIG. 5 shows that the corner 11a of the inner surface 11 is formed as a chamfered surface while the corner 13a of the outer surface 13 is formed.
a is formed on the R surface. In FIG. 6, the corner 11a of the inner surface 11 and the corner 13a of the outer surface 13 are both formed on the R surface. The corners of the precast member 10 according to the present invention may be formed in any of the above-described forms, and any of the forms can provide the above-described effects.

[0023]

As described above, according to the precast concrete member for constructing a concrete pillar according to the first aspect, since it is thin, it is extremely lightweight and can be handled very easily, such as transporting or assembling on site. In addition, work efficiency can be improved, and material costs can be reduced because unnecessary materials are not used. In addition, the thick part formed at the center of each side forming a rectangle as a whole is used as a reinforcing rib.
The thin and thick sides are effectively reinforced to realize a product that is thin and reliable in terms of strength. Moreover, since each corner of the inner surface is formed on the R surface, when concrete is poured into the inside of the precast member at the site, the cast concrete is completely filled up to this corner, and It is possible to reliably prevent voids from being formed between the precast member and the cast concrete, and to reliably prevent adverse effects due to the presence of voids, such as cracks in the precast member.

According to the second or third aspect of the present invention, the weight reduction of the precast member according to the present invention can be efficiently realized without lowering the required strength of the precast member.

[Brief description of the drawings]

FIG. 1 is a front view showing a precast concrete member for constructing a concrete column according to an embodiment of the present invention.

FIG. 2 is an overall side view of the precast concrete member for constructing a concrete column shown in FIG.

FIG. 3 is an enlarged cross-sectional view of the precast concrete member for constructing a concrete column shown in FIG.

FIG. 4 is a partial front view showing another embodiment of the precast concrete member for constructing a concrete column according to the present invention.

FIG. 5 is a partial front view showing another embodiment of the precast concrete member for constructing a concrete pillar according to the present invention.

FIG. 6 is a partial front view showing still another embodiment of the precast concrete member for constructing a concrete column according to the present invention.

FIG. 7 is an elevation view showing a construction example using a precast concrete member for constructing a concrete column according to the related art and the present invention.

FIG. 8 is an elevational view showing a construction example using the conventional and precast concrete members for constructing a concrete column according to the present invention, following FIG. 7;

FIG. 9 is an elevation view showing a construction example using the precast concrete members for constructing concrete columns according to the related art and the present invention, following FIG.

FIG. 9 shows an example of construction using a precast concrete member for constructing a concrete column according to the present invention and a conventional example.
FIG.

FIG. 11 is a front view showing a configuration example of a conventional precast concrete member for constructing a concrete column.

[Explanation of symbols]

Reference Signs List 10 Precast concrete member for concrete pillar construction 11 Inner surface 11a Corner 12 Thick part a Outer side dimension b Thick part width dimension t Side part thickness t 'Thick part thickness

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-50-28127 (JP, A) JP-A-59-199952 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) E04C 3/00-3/46 E04B 1/16

Claims (3)

(57) [Scope of request for utility model registration] 1. A concrete column having a substantially rectangular cross section as a whole and having a predetermined length, and concrete being cast inside at a pillar construction site to be integrated with the cast concrete. In the precast concrete member for constructing a concrete column, a central portion along a side direction of each side forming a rectangular section is reinforced by projecting an inner surface of the precast concrete member for constructing a concrete column toward the center .
A thick part having a predetermined width functioning as a reinforcing rib for forming the concrete column is continuously formed in the longitudinal direction of the precast concrete member itself for constructing the concrete pillar, and the thickness of each side part excluding the thick part is outside. A precast concrete member for constructing a concrete column, wherein the dimension is set to 3 to 6% with respect to a side dimension, and at least four corners of the inner surface are formed as curved or chamfered surfaces. 2. A method according to claim 1, wherein the width of the thick portion is 1 to the outer dimension.
The precast concrete member for constructing a concrete column according to claim 1, wherein the dimension is set to 2 to 25%. 3. The concrete according to claim 2, wherein the thickness of the thick portion is set to a size of 120 to 150% with respect to the thickness of sides other than the thick portion. Precast concrete members for pillar construction.