JPH10166330A - Compression molding method of concrete article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To implement readily the dehydration or deaeration of excess water in the center of a concrete surface without the common use of vacuum for discharging excess water, and form a concrete surface having small vacants by ensuring the drainage of excess water by means of a dehydration plate. SOLUTION: A hydration plate 4 is put on the upper surface of concrete, and further an upper form 5 is mounted thereon to thus compress the upper form 5 mechanically for conducting compression molding while concrete is subjected to compaction. Excess water and air in concrete are discharged outward through the dehydration plate 4. Then, the upper form 5 and dehydration plate 4 are removed from the upper surface concrete compacted on the order of carrying out feasible mold release. The exposed concrete upper surface is rendered uniform. After the upper form 5 is mounted on the concrete surface again, mechanical compression is given before hardening, and a predetermined strength is secured after the advent of concrete strength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure molding method for producing a high-strength concrete product having an excellent appearance.

[0002]

2. Description of the Related Art As one of the methods for producing a high-strength concrete product, particularly a concrete product exhibiting a high strength from an early stage, a so-called pressure molding method in which concrete packed in a formwork is compacted by pressing. Methods are known.

[0003]

In the normal pressure molding method, the upper mold is pressed to compact the hardened concrete, so that there is an unavoidable tendency of the side concrete to be compacted first, and the central part is hardened. Since the product is press-formed and cured while containing excess water and air that has lost its escape, vacancies are present on the surface of the product, and the product generally has a dirty appearance. for that reason,
It was necessary to shape the surface of a fully cured product after curing, and this work required a great deal of labor.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the above-mentioned labor for shaping the product surface by performing pressure molding with almost no voids on the surface of the product.

According to the present invention, (A) rebars and concrete are placed in a formwork, and a dewatering plate having a wire mesh layer and an upper formwork are placed on the upper surface of the cast concrete in the order of: (B) removing the upper mold frame and the dehydrating plate from the upper surface of the uncured concrete molded product to shape the concrete, and (C) forming the concrete. A method of press-forming a concrete product, comprising the steps of placing the upper mold again on the upper surface of the molded product, pressurizing the upper mold and curing the concrete molded product under pressure.

A first point of the present invention is that a dewatering plate having a flow path for escaping surplus water or air existing at the center of the upper surface of a concrete product is interposed between the upper surface of the concrete and the upper mold. The second point is that the product surface is shaped immediately after the pressure molding where the product surface is not yet sufficiently cured.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings, taking as an example a case where a concrete segment is manufactured as a concrete product.

FIG. 1 is a front view showing an example of the configuration of a formwork when manufacturing a concrete segment.
FIG. 2A is a cross-sectional view showing details of an example of a dewatering plate, and FIG.
FIG. 2B is an enlarged view of a portion A of FIG. 2A, and FIG. 2C is an enlarged view of a portion A of another example of the dehydrating plate.

[0009] The formwork is a bottom form 1, side form 2,
In the present invention, the dewatering plate 4 is provided immediately below the upper mold 5 in addition to the end mold 3 and the upper mold 5.
Is used. (See FIG. 1) The dehydrating plate 4 has a dehydrating hole 9 as shown in FIG.
It is composed of a steel sheet 14 provided with a wire mesh layer fixing frame 10 on four sides, a wire mesh layer 12, and a support 15, and the wire mesh layer 12 is bent and fixed to the wire mesh layer fixing frame 10 with screws 11. Excess water is discharged out of the mold through the wire mesh layer 12 and the dewatering holes 9 by the pressure applied to the upper mold. At the same time, the air in the mold is discharged. The wire mesh layer 12 is shown in FIG.
As shown in (b), the wire mesh layer 12 alone is sufficient,
As shown in FIG. 2C, the woven fabric layer 13 is overlapped, and the water collecting layer 8 utilizing the water absorption of the woven fabric layer 13 due to the capillary phenomenon.
May be formed. The material of the woven fabric may be any material, but a material having excellent durability against concrete and high mechanical strength is preferable. From such a viewpoint, an appropriate one is selected from various natural fiber fabrics, synthetic fiber fabrics, carbon fiber fabrics, and glass fiber fabrics. In the figure, an example is shown in which the wire mesh layer 12 is attached to the wire mesh layer fixing frame 10 by screwing the screws 11, but as another method, the end of the wire mesh layer is inserted into the concave portion of the wire mesh layer fixing frame 10. May be adopted, which is relatively easy to attach and detach, for example, by pressing and fixing together with a rod-shaped elastic body.

An operation of manufacturing a concrete segment using the illustrated formwork and the dewatering plate 4 will be described step by step.

(1) Bottom form 1, side form 2,
After assembling the end form 3 and installing predetermined reinforcing bars and predetermined inserts inside, the form is filled with hardened concrete.

(2) The dewatering plate 4 is placed on the upper surface of the concrete, and the upper mold 5 is further placed thereon, and the upper mold 5 is mechanically pressed (about 10 kgf / cm ² or more) to compact the concrete. Press molding while pressing. Excess water and air in the concrete are discharged to the outside through the dewatering plate 4.

(3) The upper mold frame 5 and the dewatering plate 4 are removed from the concrete upper surface compacted to such an extent that the mold can be removed.

(4) The exposed concrete upper surface is shaped.

(5) The upper mold 5 is placed again on the upper surface of the concrete and cured by mechanically pressurizing (approximately 5 to 10 kgf / cm ² ) and waiting for the concrete to develop strength. The upper mold 5 is removed, the side mold 3 is opened, and a concrete segment as a product is taken out of the mold.

The concrete segment is manufactured by the above operation, but the dewatering plate 4 removed in the above (3) is cleaned for the wire mesh layer 12 and the dewatering hole 9 and reused for the production of the next concrete segment. The washing of the dewatering plate 4 is usually easily performed by flowing high-pressure water back to the wire mesh layer 12 from the dewatering holes 9 while the wire mesh layer 12 is attached to the dewatering plate 4. If the clogging of the wire mesh layer 12 cannot be removed only by the backflow of water, the wire mesh layer 12 is removed from the wire mesh layer fixing frame 10 and the wire mesh layer 12 is sufficiently washed to eliminate the clogging. Fixed to.

[0017]

The present invention is configured as described above,
The following effects are obtained.

Since the excess water discharge path is secured by the dewatering plate, the excess water can be easily dehydrated and degassed at the center of the concrete surface without using vacuum for discharging the excess water. A concrete surface with few places can be obtained.

Since the shaping of the concrete surface is carried out immediately after the pressure molding in which the product surface is not yet sufficiently hardened, it requires much less labor than the conventional method performed after the hardening is sufficiently hardened. It can be carried out.

The wire mesh layer is removably attached to the dehydrating plate via the wire mesh layer fixing frame, so that the wire mesh layer can be replaced and cleaned efficiently.

In summary, it is possible to efficiently produce a concrete product having high strength and excellent appearance with little labor.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of a configuration of a mold when manufacturing a segment.

2A is a cross-sectional view showing details of an example of a dewatering plate, FIG. 2B is an enlarged view of a portion A of FIG. 2A, and FIG. 2C is a portion A of another example of the dewatering plate It is an enlarged view.

[Explanation of symbols]

1 bottom mold, 2 side mold, 3 end mold, 4 dehydration plate, 5 top mold, 6 guide roller, 7 guide, 8 water collection Layer 9 Dehydration hole 10 Wire mesh layer fixing frame 11 Screw 12 Wire mesh layer 13 Fabric layer 14 Steel plate 15 Support

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masanori Ikeda 2-3-2 Shiba, Minato-ku, Tokyo Inside Geostar Co., Ltd.

Claims (2)

[Claims] 1. (A) Reinforcement and concrete casting are performed in a formwork, and a dewatering plate provided with a wire mesh layer and an upper formwork are placed in this order on the upper surface of the cast concrete. (B) a step of removing the upper mold frame and the dehydrating plate from the upper surface of the uncured concrete molded product to shape the upper surface of the concrete molded product, and (C) forming the concrete molded product. A step of placing the upper mold again on the upper surface of the substrate, pressurizing the upper mold and curing the concrete molded product under pressure. 2. The method according to claim 1, wherein the periphery of the wire mesh layer is bent along the periphery of the dewatering plate and is fixed to a frame provided on the upper surface of the periphery of the dewatering plate.