JPH05133095A - Work execution method for placing concrete - Google Patents

Abstract

PURPOSE:To smoothen a finished surface in the case of using a mold made of a conifer having an irregular grain by releasing the mold before completely hardening the placed concrete and polishing the surface including a brittle layer. CONSTITUTION:When a concrete structure such as wall is formed by use of a mold made of a rough-grained conifer in spite of the South Sea materials, a releasing agent is applied to the contact surface with concrete. After placing, compaction is conducted through a vibrator, and concrete is charged in the inner part of the mold body. Thereafter, it is allowed to change on standing while forming the form of a concrete surface 12a. At this time, the grain of the concrete contact surface is transferred to form irregularities on the concrete surface 12a. The wood component is also eluted near the surface 12a to form a brittle layer 121 having poor concrete hardening. The mold is thus released before sufficiently hardening the concrete, and the surface 12a is ground to remove the brittle layer 12. Further, the resulting concrete surface 12a' is polished and finished smooth to form a structure having a hard surface layer part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete pouring construction method for constructing a concrete structure using a mold made of softwood.

[0002]

2. Description of the Related Art Conventionally, a formwork for placing concrete has been
Plywood made from southern timber (a tree that grows in tropical rainforests) has been widely used. Recently, the number of tropical rain forests has been decreasing, and there is an urgent need to reduce the consumption of plywood using South Sea timber in order to prevent the collapse of the balance of the global ecosystem. However, in the formwork for concrete pouring, use materials such as metal, synthetic resin, ceramic,
It is not possible to replace it with all plywood made from Southern Ocean materials due to workability and cost issues. Therefore, attempts have been made to use coniferous timber from artificial coniferous forests in which felling and afforestation are well balanced, as a material for plywood for formwork.

[0003]

By the way, since plywood made from South Sea wood, which has no knots or annual rings and has a constant thickness, has a fine grain on the surface, a plywood made from South Sea wood should be used as a formwork. The poured concrete has a substantially uniform surface. In contrast, coniferous trees have large knots and annual rings, so concavities and convexities are formed on the surface of the concrete that was placed in the formwork using plywood made of coniferous wood, with the grain of the coniferous wood being transferred. To be done. Further, when the wood component contained in the softwood material is eluted into the cast concrete, the concrete causes curing failure near the contact surface with the mold. Therefore, when the concrete poured into the mold using the softwood material is exposed, not only the appearance is unsightly because the uneven surface is formed on the finished surface of the concrete, but also the surface layer of the concrete is fragile and peels off. It is very dangerous.

In view of the above-mentioned circumstances, the present invention uses a mold made of softwood to form a concrete structure having an excellent finished surface smoothness and a robust surface layer portion, and concrete placing construction. It provides a method.

[0005]

The present invention relates to a concrete placing construction method using a formwork (1) having a plate-like member (3), and at least a concrete contact surface (3a) of the plate-like member (3). Is formed of a softwood material, the plate-like member (3) is provided with a release material (13) so as to be impregnated from the concrete contact surface (3a), and the concrete (1) is poured into the formwork (1). When 11) has reached the design initial strength, the formwork (1) is removed, and the concrete surface (12a) that was in contact with the concrete contact surface (3a) is passed through the concrete surface layer grinding means (15). It is configured to be removed by. Note that ()
The numbers in the drawings indicate the corresponding elements in the drawings for convenience, and the present description is not limited to the description in the drawings. below

The same applies to the column of [Operation].

[0006]

According to the present invention, the concrete surface layer grinding means (15) has the structure described above.
Acts to remove a).

[0007]

1 is a view showing an example of an assembled state of a mold used in the present invention, FIG. 2 is a vertical sectional side view of a dam plate portion in the mold shown in FIG. 1, and FIG. Fig. 4 is a diagram showing a part of the concrete placing construction method according to the present invention, Fig. 4 is a diagram showing a part of the concrete placing construction method according to the present invention,

As shown in FIG. 1, the formwork 1 has a frame body 2 which is assembled in the shape of an open box in accordance with the shape of the cast concrete. It is formed so as to open in the E direction. Also, the frame 2
In the lower part of the figure, that is, on the arrow F direction side, the concrete poured into the frame body 2 is connected to the lower structure in the form of being spliced to a slab or the like. A plurality of weir plates 3 made of plywood formed by laminating softwood materials in a plate shape are provided on the sides of the frame body 2 in the directions of arrows A, B, C, and D in a properly assembled manner. The barrier plate 3 is impregnated with a release agent 13 made of paraffin, oil and fat, synthetic resin, or the like in advance from one surface side of the barrier plate 3 (that is, the concrete contact surface 3a side), and the frame 2 It is painted so that it will be placed inside. On the dam plate 3, concrete contact surfaces 3a are respectively formed so as to face inward of the frame body 2, and on the concrete contact surfaces 3a, a grain of softwood is inevitably drawn, which is slightly different. Unevenness is formed. In addition, a plurality of separators 5 are provided inside the frame body 2 for holding the gaps between the dam plates 3 and 3 facing each other in the directions of arrows C and D. , Are supported by the barrier plates 3 and 3 facing each other. Also, the frame 2
A plurality of thick square members 7 are provided on the outside of the so as to be properly assembled in a form of supporting the barrier plate 3. And the frame 2
Reinforcing bars and the like are appropriately arranged inside the inside of the car based on the design specifications.

Since the formwork 1 has the above structure,
In order to construct a concrete structure such as a pillar or a wall using the formwork 1, as shown in FIG. 1, a kneaded green concrete 11 pumped from a concrete pump 9 is fed through a pump pipe 10 In the form of being thrown into the frame 2 from the upper middle,
To set. Then, as shown in FIG. 2, while the compacted material is compacted via a vibrator or the like so that the poured concrete 11 is in close contact with the concrete contact surface 3a of the barrier plate 3, the frame body 2 is formed to the height of the concrete skeleton 12 to be constructed. Fill inside. Then, the concrete 11 filled in the frame body 2 is gradually hardened while the shape of the concrete surface 12a is formed by the concrete contact surface 3a. Now the concrete frame 12 placed in this way
In the inside of the frame body 2, irregularities are formed on the concrete surface 12a in such a manner that the irregularities of the grain of the concrete contact surface 3a are transferred. In addition, a fragile layer 121 is formed near the concrete surface 12a in a form in which the wood component of the dam plate 3 is eluted and the concrete 11 is deficient in hardening. Therefore, when the concrete skeleton 12 reaches the initial design strength, that is, without waiting for the concrete 11 to fully harden, the support member 6 is loosened to remove the concrete skeleton 12 as shown in FIG. The mold 1 is demolded. At this time, since the release agent 13 impregnated in the dam plate 3 is arranged on the concrete contact surface 3a side, the dam plate 3 can be easily removed from the concrete skeleton 12. Then, as shown in FIG. 4, the concrete surface 12a is subjected to a fragile layer 12 through a grinding means 15 such as a sander attached to a manipulator or a concrete cutter.
1 is removed by scraping off, and the concrete surface 12a ′ from which the brittle layer 121 is removed is polished to obtain a smooth finish. At this time, the concrete skeleton 12 is still in a state in which the strength is not sufficiently developed, and the fragile layer 121 portion is further fragile because the wood component of the barrier plate 3 and the component of the release agent 13 are eluted. Therefore, the fragile layer 121 and the concrete surface 12a on which the unevenness is formed are removed.
Polishing a'can be done very easily. In this way, after the concrete surface 12a ′ is finished to be smooth and then sufficiently cured, the concrete skeleton 12 has a concrete structure in which the finished surface has excellent smoothness and the surface layer portion is robust.

In the above-mentioned embodiment, an example of constructing a reinforced concrete structure such as columns and walls using the mold 1 made of softwood is described, but the concrete structure to which the present invention is applied is limited to this. Not being done, for example,
It may be used for constructing horizontal structural parts such as beams and ceilings, and the type of concrete 11 used in the present invention is not limited. Further, the release agent 13 described in the above-mentioned embodiment may be replaced with another type of release agent, and the grinding means 15 for finishing the surface of the concrete skeleton 12 may be appropriately replaced with another grinding means. It doesn't matter.

[0011]

As described above, according to the present invention,
In a concrete pouring construction method using a formwork 1 having a plate member such as a barrier plate 3, at least the concrete contact surface 3a of the plate member is formed of a softwood material, and the plate member is provided with a release material 13. The concrete contact surface 3a was provided so as to be impregnated, and when the concrete 11 cast on the mold 1 reached the initial design strength, the mold 1 was removed and the concrete contact surface 3a was contacted. Since the concrete surface 12a is configured to be removed through the concrete surface layer grinding means such as the grinding means 15, the concrete surface layer grinding means can remove the concrete surface 12a. Therefore, the concrete skeleton 12 has a fragile layer in which the surface of the concrete 12a has irregularities due to the grain of softwood, and the wood component of the barrier plate 3 and the components of the release agent 13 are eluted into the concrete surface layer portion, which causes poor curing. Although the design initial strength is reached in the state where 121 is formed, the concrete surface 1
The 2a and the fragile layer 121 are removed through the concrete surface layer grinding means, so that a concrete structure having excellent surface smoothness and a solid surface layer portion is finished. The demolding work of the concrete skeleton 12 from the formwork 1 and the grinding work of the concrete surface 12a are both performed at the time when the concrete 11 reaches the design initial strength, that is, before the strength is sufficiently developed, so that it is easy. And it can be done reliably.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of an assembled state of a mold used in the present invention.

FIG. 2 is a vertical sectional side view of a dam plate portion in the form shown in FIG.

FIG. 3 is a diagram showing a part of a concrete pouring construction method according to the present invention.

FIG. 4 is a view showing a part of a concrete pouring construction method according to the present invention.

[Explanation of symbols]

 1 ... Formwork 3 ... Weir plate (plate-shaped member) 3a ... Concrete contact surface 12a ... Concrete surface 13 ... Peeling material 15 ... Grinding means (concrete surface layer grinding means)

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[Procedure amendment]

[Submission date] September 18, 1992

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Fig. 2]

[Figure 4]

[Figure 1]

[Figure 3]

Claims (1)

[Claims] 1. A method of placing concrete using a form having a plate-shaped member, wherein at least concrete contact surface of the plate-shaped member is formed of a softwood material, and the plate-shaped member is provided with a release material and the concrete contact surface. When the concrete poured into the form has reached the design initial strength, the form is removed, and the concrete surface that has been in contact with the concrete contact surface is ground to the concrete surface layer portion. A method for placing concrete, which is constructed so as to be removed through a means.