JP6865007B2 - Precast concrete foundation and its manufacturing method - Google Patents

Description

The present invention relates to a precast concrete foundation in a building and a method for manufacturing the same.

Conventionally, it has been known that precast structures used for building foundations are manufactured by horizontal casting, in which concrete is poured into a horizontal formwork and surface finishing such as ironing is performed before the concrete hardens. .. In the precast structure produced in this manner, the bottom surface of the formwork becomes a smooth surface without unevenness, and the iron-finished surface becomes a substantially uneven surface having a leveling groove or the like.

When the precast structure is installed on the foundation of a building, from the viewpoint of improving the design of the exterior of the building, the smooth bottom of the formwork without unevenness is installed so that it faces the outdoor side, and the iron-finished surface has a substantially uneven shape. Is known to be installed facing the bottom of the floor of the building.

On the other hand, Japanese Patent Application Laid-Open No. 8-218389 (Patent Document 1) discloses a method for manufacturing a precast member that employs horizontal striking in which a mold is assembled and a beam is laid down.

Japanese Unexamined Patent Publication No. 8-218389

Since the foundation of the building is the foundation of the building, it has been required to improve its durability. On the other hand, although Patent Document 1 discloses a method of manufacturing a precast member by horizontal striking, it does not mention how to arrange the precast member manufactured by horizontal striking on the foundation of a building. ..

The present invention has been made to solve the above problems, and an object of the present invention is to provide a precast concrete foundation and a method for manufacturing the same, which can easily improve durability. ..

The precast concrete foundation according to one aspect of the present invention includes a wall-shaped precast structure extending in the horizontal direction, the lower edge of the precast structure is supported on the ground side, and the upper edge of the precast structure is the outer wall of the building. One side facing the outside of the building is the top surface, and the other side facing the inside of the building is the formwork finishing surface.

Preferably, the embedded hardware is provided on the finished surface of the formwork.

The method for manufacturing a precast concrete foundation according to one aspect of the present invention includes a step of preparing a horizontal formwork in which a concrete casting space is formed by a bottom plate and side plates erected from the outer periphery of the bottom plate, and concrete casting of the formwork. The process of placing concrete in the space, the process of removing the precast structure having the top surface of the concrete and the finished surface of the formwork facing the bottom plate of the formwork from the formwork after the concrete has hardened, and the process of removing the top surface from the formwork. This includes a step of installing the precast structure so that the end face faces the outside of the building and the formwork finishing surface facing the inside of the building, and a step of fixing the lower edge of the precast structure to the ground side.

According to the present invention, it is possible to provide a precast concrete foundation whose durability can be easily improved and a method for manufacturing the same.

It is a schematic diagram which shows the casting state of the precast structure by the horizontal formwork. It is a schematic diagram which shows the state which took out the precast structure from the state of FIG. It is a schematic diagram which shows the state which put the precast structure vertically from the state of FIG. It is sectional drawing of the precast concrete foundation which concerns on this embodiment. It is a schematic diagram which shows the building using the precast concrete foundation which concerns on this embodiment.

Embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals, and the description thereof will not be repeated.

First, a general precast concrete foundation will be briefly described.

When the precast structure used for the foundation of a building is manufactured by horizontal striking, the bottom surface of the formwork becomes a smooth surface without unevenness, and the iron-finished surface becomes a substantially uneven surface. When this precast structure is used as a precast concrete foundation, in order to improve the design of the exterior of the building, a smooth formwork bottom surface without unevenness is installed so as to face the outdoor side, and a substantially uneven iron-finished surface. Is installed so that it faces the underfloor space of the building.

When the precast structure reacts with carbon dioxide and the like contained in the atmosphere, the concrete is neutralized over time, causing cracks and the like. In other words, one of the causes of reducing the durability of precast concrete foundations is the neutralization of concrete. On the other hand, the iron-finished surface of the precast structure has a large water-cement ratio and is porous as compared with the bottom surface of the formwork due to gravity.

As a result of intensive research, the inventor of the present application has an average humidity of about 50 to 60% in the underfloor space, and air tends to stay there. Therefore, concrete is more likely to be neutralized than outdoors where the environment changes daily. We found that it is an environment, that is, a space where the rate of neutralization of concrete is high. Furthermore, as described above, the iron-finished surface has a large water-cement ratio and is porous, so if it is installed facing the underfloor space where the concrete neutralization rate is high, the precast structure will be neutralized at a high rate. I found that it could be faster.

Therefore, in the present embodiment, the iron finishing surface is installed so as to face the outside of the building, and the formwork finishing surface faces the underfloor space side of the building. The precast concrete foundation 3 according to the present embodiment will be described in detail below. Prior to the description of the precast concrete foundation 3 according to the present embodiment, a method of manufacturing the precast structure 1 constituting the precast concrete foundation 3 will be described.

<About precast structure>
With reference to FIGS. 1 to 3, the precast structure 1 is, for example, a block body having a substantially rectangular parallelepiped outer shape. In the description of the precast structure 1, the horizontal direction indicated by the arrow A1 in FIG. 1 is referred to as a left-right direction. The direction indicated by the arrow A2 in FIGS. 1 and 3 is referred to as the vertical direction.

With reference to FIG. 1, the precast structure 1 is manufactured using a substantially rectangular horizontal formwork 2. The horizontal formwork 2 is integrally composed of a bottom plate 21 and side plates erected from the outer periphery of the bottom plate 21, that is, a front plate 22, a rear plate 23, a right side plate 24, and a left side plate 25. As a result, the concrete casting space 26 is formed in the space surrounded by the bottom plate 21, the front plate 22, the rear plate 23, the right side plate 24, and the left side plate 25. The widths of the bottom plate 21, the front plate 22, and the rear plate 23 are formed to be longer than those of the right side plate 24 and the left side plate 25.

An embedded metal fitting 17 to be embedded in concrete is arranged on the bottom plate 21 of the horizontal formwork 2. Further, in order to embed the steel frame in the concrete, the steel frame (not shown) is placed sideways in the concrete placing space 26 in a state of being laid down. In this state, concrete is poured into the concrete placing space 26. Before the concrete hardens, for example, smooth the top surface of the concrete with a trowel. After the concrete has hardened, the substantially cubic precast structure 1 is removed from the formwork 2 as shown in FIG.

The precast structure 1 has a trowel finished surface 10 which is a top surface smoothed with a trowel or the like, a formwork finished surface 11 facing the bottom plate 21, a front surface 12 facing the front plate 22, a rear surface 13 facing the rear plate 23, and a right side. It has a right side surface 14 facing the plate 24 and a left side surface 15 facing the left side plate 25.

As described above, the iron-finished surface 10 is a surface that is artificially smoothed with a trowel or the like, so that substantially unevenness such as uneven leveling is formed. Further, the iron-finished surface 10 has a large water-cement ratio due to gravity and becomes porous. On the other hand, since the formwork finished surface 11 is a surface formed so as to face the bottom plate 21 of the formwork 2, it is a smooth surface having substantially no unevenness. Further, the formwork finished surface 11 has a smaller water-cement ratio than the iron finished surface 10, and is not porous but a dense surface. Further, the embedded metal fitting 17 is embedded in the formwork finished surface 11. The front surface 12, the rear surface 13, the right side surface 14 and the left side surface 15 are smooth surfaces having substantially no unevenness, similar to the formwork finished surface 11.

Next, as shown in FIG. 3, the precast structure 1 of FIG. 2 is vertically placed so that the front surface 12 of the precast structure 1 faces downward and the rear surface 13 faces upward. By arranging a plurality of precast structures 1 in this state in a wall shape so as to extend in the horizontal direction, the precast structure 1 can be used for the precast concrete foundation 3.

<About precast concrete foundation>
FIG. 4 is a cross-sectional view of the precast concrete foundation 3 according to the present embodiment, and FIG. 5 is a schematic view showing a building 100 using the precast concrete foundation 3 according to the present embodiment. In the description of the precast concrete foundation 3, the direction indicated by the arrow A2 in FIG. 4 is referred to as the vertical direction, the outdoor indicated by the arrow A3 is referred to as the outside, and the underfloor space 4 indicating the direction opposite to the arrow A3 is referred to as the inside.

With reference to FIGS. 4 and 5, the precast concrete foundation 3 includes a wall-shaped precast structure 1 extending in the horizontal direction. The lower edge of the precast structure 1 is supported on the ground 200 side, and the upper edge of the precast structure 1 supports the outer wall 101 of the building 100. One side facing the outside of the building 100 is the iron finishing surface 10, and the other side facing the inside of the building 100 is the formwork finishing surface 11.

Specifically, the front surface 12 of the precast structure 1 is erected on a flat base portion 102 along the ground 200, and is directed upward in the vertical direction of the building 100 in a direction orthogonal to the base portion 102. It is arranged so as to protrude. The rear surface 13 of the precast structure 1 supports the cross member 104 provided below the floor 103 of the building 100 from below. The cross member 104 is supported by the precast structure 1 via the fixed metal fitting 105. An underfloor space 4 is formed in a space surrounded by a plurality of precast structures 1, a cross member 104, and a ground 200.

The fixed hardware 105 has a receiving portion 106 for accommodating the cross member 104 from below, and a connecting portion 107 for connecting the receiving portion 106 and the precast structure 1. The connecting portion 107 includes a horizontal plate portion 108 located between the receiving portion 106 and the precast structure 1, and a vertical plate portion 109 connected to the horizontal plate portion 108 and along the formwork finished surface 11 of the precast structure 1. .. The vertical plate portion 109 is provided with a through hole. The fixing metal fitting 105 is attached to the embedded metal fitting 17 by inserting the bolt 110 into the through hole of the embedded metal fitting 17 provided in the formwork finished surface 11 of the precast structure 1 and the through hole of the vertical plate portion 109. The member for attaching the cross member 104 to the precast concrete foundation 3 is not limited to the shape of the fixed metal fitting 105 as shown in FIG.

In the present embodiment, the iron finishing surface 10 of the precast structure 1 is arranged so as to face the outdoor side, and the formwork finishing surface 11 is arranged so as to face the underfloor space 4. As a result, the formwork finished surface 11 has a small water-cement ratio and is a dense concrete surface, so that even if the formwork finished surface 11 is arranged so as to face the underfloor space 4 having a high neutralization rate, the precast concrete foundation 3 is neutral. The progress of conversion is slowed down and durability is improved.

Further, since the uneven iron-finished surface 10 is arranged so as to face the outdoor side, it is necessary to coat the iron-finished surface 10 with a paint or the like in order to improve the design in appearance. Further, by applying a coating on the iron-finished surface 10 having a large water-cement ratio, it is possible to improve the performance against general neutralization.

In a general manufacturing method, the embedded metal fitting 17 is arranged on the iron-finished surface 10 because it is arranged on the underfloor space 4 side. When the embedded metal fitting 17 is provided on the iron finishing surface 10, it is necessary to avoid the embedded metal fitting 17 when smoothing with the iron, and it is necessary to float the embedded metal fitting 17 on the iron finishing surface 10, so that the manufacturing efficiency is high. Was bad.

On the other hand, in the present embodiment, the embedded metal fitting 17 is arranged on the underfloor space 4 side, but the formwork finished surface 11 is arranged so as to face the underfloor space 4. As a result, the embedded metal fitting 17 is provided on the formwork finished surface 11 and not on the iron finished surface 10. Therefore, the iron-finished surface 10 can be easily smoothed with the iron, and the embedded metal fitting 17 only needs to be arranged on the bottom plate 21 by a magnetic force or the like, so that the manufacturing efficiency is improved.

Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the illustrated embodiments. Various modifications and modifications can be made to the illustrated embodiment within the same range as the present invention or within the same range.

1 Precast structure, 2 Formwork, 3 Precast concrete foundation, 4 Underfloor space, 10 Iron finished surface, 11 Formwork finished surface, 12 Front, 13 Rear, 14 Right side, 15 Left side, 17 Hardware, 21 Bottom plate, 22 Front plate, 23 rear plate, 24 right plate, 25 left plate, 26 concrete casting space, 100 building, 101 outer wall, 102 base, 103 floor, 104 cross member, 105 fixed hardware, 106 receiving part, 107 connecting part, 108 horizontal plate part, 109 vertical plate part, 110 bolts, 200 ground.

Claims (3)

With a horizontally extending wall-shaped precast structure,
The lower edge of the precast structure is supported on the ground side, and the upper edge of the precast structure supports the outer wall of the building.
It is a flat surface, and one side facing the outside of the building is the top surface.
A precast concrete foundation in which the other surface facing the underfloor space of the building is a formwork finishing surface. The precast concrete foundation according to claim 1, wherein an embedded metal fitting to which a fixed metal fitting connecting the precast structure and the outer wall of the building is attached is provided on the formwork finished surface. A process of preparing a horizontal formwork in which a concrete placing space is formed by a bottom plate and a side plate erected from the outer periphery of the bottom plate
The process of placing concrete in the concrete placing space of the formwork and
After the concrete has hardened, a step of removing the precast structure having a top surface which is a flat surface of the concrete and a formwork finished surface facing the bottom plate of the formwork from the formwork.
The process of painting the top surface and
A process of installing the top surface so as to face the outside of the building and the formwork finishing surface so as to face the underfloor space of the building.
A method for manufacturing a precast concrete foundation, which comprises a step of fixing the lower edge of the precast structure to the ground side.

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