JPH0625418U - Precast concrete members for building concrete columns - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a precast concrete member for constructing concrete columns, which is lightweight and strong, and which can realize complete filling of cast-in-place concrete. [Constitution] In a precast concrete member 10 for constructing a concrete column, which has a tubular shape having a substantially square cross section as a whole, and which constitutes a concrete column by placing concrete inside at a site for constructing the column,
The central portion of each side portion forming the square was set as the thick portion 12. In addition, the thickness t of each of these sides excluding this thick portion 12
Was set to a dimension of 3 to 6% with respect to the outer dimension a. Further, the four corners 11a of the inner surface 11 are curved or chamfered.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 INDUSTRIAL APPLICABILITY The present invention is a precast concrete member for concrete column construction, which is used as a formwork for concrete pouring at the time of concrete column construction and, after concrete pouring, forms concrete columns together with the concrete for pouring. Concerned.

[0002]

[Prior art]

 Conventionally, the method of constructing concrete columns has generally been a method of completely building on site or using precast columns. In the case of the completely on-site construction, the formwork is assembled so as to surround the column rebars already assembled on the site where the columns should be constructed, concrete is placed in the formwork, and the formwork is set after the concrete is set. Concrete columns will be constructed by removing them. In the case of using precast pillars, concrete pillars of all cross-sections are manufactured in advance at the factory, and they are erected at predetermined positions on site.

By the way, in the above-mentioned conventional means, the one constructed by a complete construction site requires time and labor for installing and dismantling the formwork, while the one using the precast column has a large member weight and is not easy to handle during transportation and installation. There was such an inconvenience. In addition, especially in the case of a completely site-constructed structure, there is an example that can be cited as one of the problems of global resources because the dam plate used as a formwork is made of wood these days.

Therefore, in recent years, a precast concrete member formed in a tubular shape has been used as a so-called formwork as a formwork for pouring concrete, and concrete is placed inside the precast concrete member to form a formwork. A method of constructing this precast concrete member used as the final column has also been developed and adopted.

7 to 10 show an example of a case where a concrete column is constructed by the above-mentioned construction method. FIG. 7 shows a state in which the column reinforcing bars 2 have already been assembled at the place where the columns on the foundation slab 1 should be constructed. After this state, as shown in FIG. 8, the precast concrete member 3 described above is suspended from above the column rebar 2. Next, as shown in FIG. 9, the built-in adjustment of the incorporated precast concrete member (hereinafter abbreviated as “precast member”) 3 is performed. Reference numeral 6 in the figure is an adjusting member (steel rod with turnbuckle, etc.) for adjusting the installation. Then, as shown in FIG. 10, after the necessary members such as the beam reinforcing bars 7 are incorporated into the upper end of the precast member 3, concrete (not shown) may be placed inside the precast member 3. The concrete column 8 is completed when the casting concrete is hardened. The length of the precast member 3 is usually set to the height of the first floor in this way. That is, this construction method can be said to be a kind of half-precast construction method applied to the pillar.

[0006]

[Problems to be solved by the device]

 Thus, by constructing a concrete column using the precast member 3 as described above, it is possible to solve both of the defects in the complete site construction and the defects in the precast column. However, the conventional precast member 3 still has the following disadvantages to be solved.

The precast member 3 is of a type in which the column reinforcing bars are integrally embedded in the concrete forming the precast member 3 in advance, and does not have the column reinforcing bars (however, crack prevention Wire mesh for use) is provided. Of these two types, the latter type has the advantages of being lighter in weight and easier to manufacture than the former type. However, in this latter type, the conventional one maximizes its superiority as a precast member 3 which has one of the greatest advantages that it is thick as a formwork and lightweight in order to secure its strength. Had the drawback that it could not be demonstrated.

Further, in the conventional precast member 3, as shown in FIG. 11 as an example, four corners 4 a of the inner surface 4 are formed in a substantially right angle shape. For this reason, when concrete is poured inside at the site, the corners are not sufficiently filled with concrete and voids are formed, which causes cracks in the precast member 3, for example. There was a horror.

The present invention has been made in view of the above circumstances, and is a precast concrete for concrete column construction that eliminates the above-mentioned drawbacks, is lightweight and strong, and can realize complete filling of cast-in-place concrete. It is intended to provide a member.

[0010]

[Means for Solving the Problems]

 The invention according to claim 1 is a concrete pillar which is formed into a tubular shape having a substantially rectangular cross section as a whole and has a predetermined length, and concrete is placed inside the pillar at a pillar construction site to be integrated with the concrete. In the precast concrete member for constructing a concrete column, the inner surface of the precast concrete member for constructing a concrete column has a predetermined width in the central portion along the side direction of each side forming the rectangular cross section. Is continuously formed in the longitudinal direction of the precast concrete member for constructing a concrete column, and the thickness of each side excluding the thick part is 3 to 6 with respect to the outer dimension. %, And at least the four corners of the inner surface are formed as curved surfaces or chamfered surfaces.

According to a second aspect of the invention, in the precast concrete member for constructing a concrete column according to the first aspect, the width of the thick wall portion is set to a dimension of 12 to 25% of the outer dimension. It is characterized by.

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

[0013]

[Action]

 In the precast concrete member for constructing a concrete column according to claim 1, a thick-walled portion formed in a central portion of each side portion of the rectangular precast concrete member reinforces each side portion, whereby a meat of each side portion is formed. Achieved a thinner wall. Also, since the four corners on the inner surface are curved or chamfered, when concrete is poured into this precast concrete member, the poured concrete is completely filled up to the corners.

The precast concrete member for constructing a concrete column according to claim 2 or claim 3 is most rational in terms of both thinning each side portion and ensuring the strength of each thinned side portion. To achieve the desired structure.

[0015]

【Example】

 Hereinafter, embodiments of the present invention will be described 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 drawings, the precast member 10 has a tubular shape having a substantially square wall 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 is a wire mesh for preventing cracks. As can be seen from FIG. 3, in the inner surface 11 of the precast member 10, the central portion of each side forming the substantially square shape projects toward the central portion of the substantially square shape formed by the inner surface 11. As a result, a thick portion 12 having a certain width is formed at the center of each side of the precast member 10.

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

Here, the thickness t of the precast member 10 is set to 3 to 6% with respect to the outer side dimension a as described above because the formwork in which concrete is placed inside is less than 3%. However, if the strength exceeds 6%, the thickness will be unnecessarily high and the material cost will increase. This is because it increases the weight and makes the work such as transportation and construction inefficient.

In the precast member 10 according to the present invention, the width b of the thick portion 12 is 12 to 25% of the outer dimension a, and the thickness t ′ of the thick portion is The thickness is set to be 120 to 150% of the thickness t. The basis for this is described below. The thick portion 12 is formed at the center of each side portion and reinforces each thin side portion. Therefore, when the width b and the wall thickness t'of the thick portion 12 are smaller than the above-mentioned set values, the reinforcing effect of the thick portion 12 may not be expected. In addition, it has the adverse effect of making it difficult to fill the concrete material. On the other hand, if the width b and the wall thickness t'each exceed the above-mentioned set values, the reinforcing portion becomes an unnecessarily large size, and the meaning of setting the wall thickness t of each side portion small as described above is lost. This is because there is a fear.

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

The precast member 10 as described above is produced by the well-known centrifugal molding method of concrete, like the conventional precast member according to the present invention. Further, the construction method using this precast member 10 may be the same as the conventional one, and for example, the construction may be carried out as shown in FIGS.

According to the above-mentioned precast member 10, firstly, since it is thin, it is extremely lightweight, and the handling such as transportation or assembling work on site is very light, and the working efficiency can be improved. . In addition, material costs are saved because wasteful materials are not used. Further, by forming the thick-walled portion 12 projecting inward at the central portion of each side forming a rectangle as a whole, each thin-sided portion is effectively reinforced, thereby realizing a thin-walled product as a whole. That is why. Further, since each corner 11a of the inner surface 11 is formed into the R surface, when the concrete is poured inside the precast member 10 on site, the poured concrete is completely filled up to the corner 11a. Become. Therefore, it is possible to reliably prevent the formation of voids between the precast member 10 and the cast concrete, and to avoid any adverse effects that may occur when the voids exist, such as cracking of the precast member 10. Can be prevented. In addition, since the corners 13a of the outer surface 13 of the precast member 10 are chamfered, the corners 13a can come into contact with obstacles or collide with objects during handling. It is possible to prevent chipping easily and is safe in handling.

4 to 6 show another embodiment of the present invention, each showing the shape of the corner of the precast member. As shown in FIG. 4, the corner 11a of the inner surface 11 is formed into a chamfered surface as well as the corner 13a of the outer surface 13. In FIG. 5, 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 as an R surface. In the structure shown in FIG. 6, both the corner 11a of the inner surface 11 and the corner 13a of the outer surface 13 are formed in the R plane. The corners of the precast member 10 according to the present invention may be formed in any of the above forms, and the effects described above can be obtained in any form.

[0023]

[Effect of device]

 As explained above, according to the precast concrete member for constructing a concrete column according to claim 1, since it is thin, it is extremely lightweight, and the handling such as transportation or assembling work on site is extremely light and the work efficiency is high. The material cost can be improved because wasteful materials are not used. In addition, a structure that effectively reinforces each thin side part by a thick part formed in the center of each side that forms a rectangle as a whole, thereby realizing a product that is thin and reliable in strength is doing. Moreover, since each corner of the inner surface is formed into the R surface, when the concrete is poured in the inside of this precast member, the poured concrete is completely filled up to this corner. Therefore, it is possible to reliably prevent the formation of a gap between the precast member and the cast concrete, and it is possible to surely prevent the occurrence of adverse effects such as cracks in the precast member due to the presence of the gap.

According to the invention as claimed in claim 2 or claim 3, it becomes possible to efficiently realize the weight reduction of the precast member according to the present invention without lowering the required strength of the precast member.

[Brief description of 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 column according to the present invention.

FIG. 6 is a partial front view showing yet 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.

8 is an elevational view showing an example of construction using a precast concrete member for constructing a concrete column according to the related art and the present invention, following FIG.

9 is an elevational view showing an example of construction using a precast concrete member for constructing concrete columns according to the related art and the present invention, following FIG. 8;

[Fig. 10] Fig. 9 is a construction example using a precast concrete member for constructing a concrete column according to the related art and the present invention.
It is an elevation view shown following.

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

[Explanation of symbols]

10 Precast concrete member for concrete column construction 11 Inner surface 11a Corner 12 Thick wall a Outer side dimension b Thick wall width dimension t Side wall thickness t ′ Thick wall thickness

Claims (3)

[Scope of utility model registration request] Claim: What is claimed is: 1. A concrete column having a substantially rectangular cross-section as a whole and having a predetermined length, and concrete is placed inside the column construction site to form a concrete column integrated with the placed concrete. In the precast concrete member for constructing a concrete column, at the central portion along the side direction of each side forming the rectangular cross section, the inner surface of the precast concrete member for constructing a concrete column projects toward the center to form a thick wall portion with a predetermined width. Is continuously formed in the longitudinal direction of the precast concrete member for constructing a concrete column, and the thickness of each side portion excluding the thick portion is set to 3 to 6% of the outer dimension. Further, at least the four corners of the inner surface are formed into a curved surface or a chamfered surface, which is a precast concrete for concrete column construction. REIT member. 2. The width of the thick portion is 1 with respect 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 120 to 150% of the thickness of the side portion other than the thick portion. Precast concrete member for pillar construction.