JPH1119913A - Composite sheet for manufacturing concrete product and manufacture of concrete product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing sheet for a unique concrete product and an excellent and low cost manufacturing method of the concrete product by employing the manufacturing sheet, with which the concrete product excellent in external appearance can be manufactured by using an existing form and in which no removing work of the concrete adhered to the form is necessary. SOLUTION: This composite sheet comprises a front surface layer made of soft rubber or plastic and a rear surface layer made of a rubber magnet layer or a plastic magnet layer. By arranging this sheet on the inner surface of the existing manufacturing form of a concrete product, a concrete product having an excellent external appearance can be easily, efficiently and economically manufactured. In addition, the releasing of the form after the finish of the manufacturing of the concrete product can be easily performed in a short period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete panel used for a building such as a building, a concrete product for a building used for an outer wall and a fence of a general house, and protection of a park, a road, a slope and the like, and a landscape. Composite sheet for concrete product production widely applied to the production of precast concrete products for civil engineering such as concrete blocks, panels, retaining walls, etc. used for improvement, and box culverts, U-shaped grooves used for passages, running water channels, etc. And a method for producing a concrete product using the same.

[0002]

2. Description of the Related Art Conventionally, in the production of concrete products widely used for construction and civil engineering, a so-called control panel such as wood, plywood or a plastic plate is used for an outer portion of a desired shape, and filled and solidified with ready-mixed concrete. Generally, a method of filling and solidifying ready-mixed concrete using a formwork of iron, steel or the like is used. In particular, in recent years, the production of concrete products has greatly increased in order to standardize manufactured concrete products, or to improve strength, quality, and dimensional accuracy, and to simplify construction, save labor, and shorten construction periods. . In the factory production of concrete products, in most cases, formwork of iron, steel, etc. (hereinafter referred to as formwork)
It has been done to use.

[0003] However, when a concrete product is manufactured using a formwork, air and a small amount of volatile substances contained therein are not sufficiently removed in the process of filling and solidifying the ready-mixed concrete. It often remains at the boundary with the inner surface of the formwork. In particular, when performing so-called steam curing in which heating is performed from outside with heating steam or the like to speed up the production and promote the solidification reaction, these appear as bubbles, holes, defects on the inside and outside surfaces of the concrete, and the outer wall, resulting in poor strength and poor appearance. Become. For this reason, after filling the ready-mixed concrete into the formwork, it is necessary to agitate the ready-mixed concrete using a jig such as a bar or the like, or to perform a deaeration operation by vibrating or rotating the formwork.

[0004] Further, due to the repetition of the production, a part of the solidified concrete adheres to the inner surface of the formwork, and not only makes it difficult to remove the concrete product, but also a part of the concrete drops, sinks, and becomes defective. It is becoming difficult to produce concrete products with a smooth appearance without any defects. For this reason, after demolding and removing concrete products,
It is essential to remove the adhered concrete from the inner surface of the formwork, but it requires a great deal of time and effort, and there is a strong demand for improvement.

In addition, in recent years, concrete products having a concrete surface are not preferred, depending on the place where the concrete products are laid and the environment, and so-called environmentally friendly products having an appearance similar to natural stone, wood, and the like are also used as concrete products. Is being asked for. In order to respond to these trends, it is necessary to hold a large number of various types of forms, but forms for concrete product production are usually extremely expensive, and due to the recent increase in the size of concrete products. However, the corresponding formwork costs are enormous.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a novel concrete product which enables the manufacture of a concrete product having an excellent appearance using an existing formwork, and which does not require the concrete removing operation of the formwork. An object of the present invention is to provide a composite sheet for producing a concrete product and an excellent and inexpensive method for producing a concrete product using the same.

[0007]

Means for Solving the Problems The present inventors use a composite sheet (hereinafter, referred to as a composite sheet) composed of a rubber or plastic having a flexible surface layer and a rubber magnet layer or a plastic magnet layer having a flexible back surface. The present inventors have found that a concrete product having a better appearance can be easily, efficiently and economically manufactured, and have completed the present invention.

[0008] The composite sheet of the present invention comprises a composite sheet comprising a flexible rubber or plastic surface layer and a flexible rubber or plastic magnet layer on the back surface layer. By installing this sheet on the inner surface of an existing concrete product manufacturing formwork, a concrete product can be manufactured easily and economically.

The flexibility of the surface layer of the composite sheet of the present invention is as follows:
It is not particularly limited as long as it has enough flexibility to be wound up during handling and use, but usually has a hardness of 5 (JIS method A).
5-85 is useful, preferably 60-80.
When the surface hardness is less than 55, the surface layer itself may be broken by repeated use, and when the hardness exceeds 85, the removal time from the mold and the opening time are increased, and the workability is remarkably deteriorated. By providing a flexible rubber magnet layer on the back layer, or a magnet layer consisting of a plastic magnet layer,
It is extremely easy to install on existing forms such as iron and steel, and it is easy to remove them from the form after the end of production, and to use the form immediately after demolding concrete products for the next production. It becomes possible.

The material of the surface layer of the composite sheet used in the present invention may be nitrile rubber, chloroprene rubber, ethylene-propylene rubber, natural rubber, soft vinyl chloride resin, vinyl chloride thermoplastic elastomer, polyethylene resin, polypropylene resin or Olefin-based thermoplastic elastomer is preferable, and the thickness is 0.1 mm to 2 mm.
Is suitable, and preferably 0.2 to 1.5 mm. When the thickness is less than 0.1 mm, it is often difficult to withstand repeated manufacturing and use, and when the thickness exceeds 2 mm, handling of the composite sheet becomes slightly difficult, for example, time is required for opening the mold.

[0011] The magnet layer on the back surface of the composite sheet is made of soft natural rubber, soft vinyl chloride resin, vinyl chloride-based thermoplastic elastomer (hereinafter referred to as vinyl chloride TPE) or chlorinated polyethylene (hereinafter referred to as CPE). And those produced by mixing magnetic powders such as oxides of nickel and the like are general, economically useful, and can be produced by a known method. The thickness of the magnet layer is effective from 0.5 mm to 2 mm. If it is less than 0.5 mm, the adhesion to the mold may be insufficient. If it exceeds 2 mm, the weight of the composite sheet increases. Handling becomes difficult when used in the manufacture of concrete products. Furthermore, the hardness of the magnet layer (JIS A)
Is effective in the range of 40 to 80, preferably 50 to 70,
If the hardness is less than 40, tearing may occur due to repeated use, and if it exceeds 80, it may take a long time to release from the mold, which is not preferable. The composite sheet may be manufactured by a known method such as an extrusion method for a sheet to be provided as a surface layer, and may be laminated by laminating the sheet and a magnet layer, or may be manufactured integrally by a method such as co-extrusion. .

Further, the attracting force of the magnet layer to the iron plate is 20 g /
cm ^{2 to} 50 g / cm ² is preferable, and when it is less than 20 g / cm ² , a displacement may occur due to vibration or the like after installation on a mold. If it exceeds 50 g / cm ² , it may be slightly difficult to remove it from the mold after the production is completed, but it is not particularly limited to this.

The flexible surface layer has a height or depth of 0.2 m.
It is also effective to have regular or irregular lines, stripes or patterns of protrusions and / or depressions of m to 2 mm (FIG. 2). It has been confirmed that by connecting these lines, strips, etc. from the lower part of the formwork to the upper surface, it is effective for removing bubbles on the surface of the concrete product. Further, the projections of the lines, stripes or patterns of the surface layer are transferred to the surface of the concrete product, so that it is possible to obtain a concrete product having a soft appearance and softness not found in the conventional concrete surface.

Further, the surface of the composite sheet may be further coated with silicone oil, oils and fats, a soap solution or the like to prevent the concrete from adhering to the surface by spraying or the like. This leads to an improvement in the manufacturing cycle, and therefore the effect of the present invention can be promoted.

The composite sheet of the present invention can be installed in an existing concrete formwork, filled with ready-mixed concrete, and then subjected to normal production means such as vibration degassing, steam curing and the like, and used for production of the product. The installation of this composite sheet makes it possible to easily release the product from the mold in a very short time, and the obtained concrete product has an excellent appearance without bubbles, chips, etc. It can be used for concrete product manufacturing.

[0016]

The present invention will be described in more detail with reference to the following examples. Examples 1 to 9 As shown in FIG. 3, a composite sheet as shown in the schematic diagram of FIG. 1 shown in Table 1 was installed on the inner surface of a magnetic metal mold having a length of 1 m, a width of 1 m and a width of 15 cm. And fresh concrete (W
/ C ratio 50%, slump 8cm, coarse aggregate size 20mm,
S / a ratio 40%, admixture 1%) was injected into the
After solidifying at room temperature for a time, the mold was removed and the surface condition of the concrete product was observed. Table 1 shows the results.

Comparative Examples 1 to 6 Tests were conducted in the same manner as in Examples 1 to 9 except that the composite sheet of the present invention was not used, and the results are shown in Table 2.

[0018]

[Table 1]

[0019]

[Table 2]

Examples 1-9 using the composite sheet of the present invention
In this case, the mold can be easily opened in a short time, and the surface of the manufactured product has very few defects such as bubbles, dents and defects. On the other hand, in Comparative Examples 1 to 6, which deviated from the scope of the present invention, it took time to release the mold, and the produced concrete product had many defects such as bubbles and defects on the surface, and the appearance was poor. Became a product.

[0021]

As is clear from the examples, in the production of a concrete product using a metal mold, the composite sheet of the present invention and the production method using the same make it easy to open the mold after solidification of the concrete, and to shorten the time. The resulting product is a concrete product having a very good appearance without surface defects.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a composite sheet.

Fig. 2 Schematic diagram of composite sheet (with streaks)

FIG. 3 is a schematic diagram of the production of a concrete product of an embodiment.

FIG. 4 is an explanatory diagram (schematic diagram) of a surface defect of a concrete product.

Claims (6)

[Claims] 1. One of nitrile rubber, chloroprene rubber, ethylene-propylene rubber, natural rubber, soft vinyl chloride resin or vinyl chloride thermoplastic elastomer.
A flexible surface layer having a thickness of 0.1 mm to 2 mm comprising a seed;
A composite sheet for manufacturing concrete products comprising a back layer made of a flexible rubber magnet layer or a plastic magnet layer. 2. A magnetic layer containing at least one of natural rubber, soft vinyl chloride resin, vinyl chloride thermoplastic elastomer, and chlorinated polyethylene and a magnetic powder having a thickness of 0.5 m.
The composite sheet according to claim 1, wherein the composite sheet has a layer of m to 2 mm. 3. The attraction force of the magnet layer to the iron plate is 20 g / cm.
Concrete products manufacturing composite sheet according to claim 1, wherein the a ^{2 ~50g} / cm ^2. 4. The method according to claim 1, wherein the surface layer has a height or a depth of 0.2 mm or more.
The composite sheet for producing a concrete product according to claim 1, wherein the composite sheet has regular or irregular lines, stripes, or patterns of projections and / or depressions of 2 mm. 5. A concrete comprising the steps of: placing the composite sheet for producing a concrete product according to claim 1 on a part or the whole of an inner surface of an iron or steel concrete form, and then filling and solidifying the form with the ready-mixed concrete. Product manufacturing method. 6. The method for producing a concrete product according to claim 5, wherein a concrete product having a pattern on its surface is obtained.