JPH08165797A - Steel form for concrete - Google Patents

Abstract

PURPOSE: To display the beauty of concrete surfaces, and to rationalize constructing work, by a method wherein the cross section of form surfaces being in contact with concrete is formed in saw-edged shape, the form surfaces are fusion-bonded with resin, and the sizes of an interval between saw-edged apexes neighboring with each other and a recessed depth are individually specified. CONSTITUTION: The cross section of form surfaces being in contact with concrete is formed in saw-edged shape, an interval between saw-edged apexes neighboring with each other is made at a length of 0.1 to 3.0mm, and a recess in the saw-edged shape is made at a depth of 0.1 to 5.0mm. After that, the form surfaces are fusion-bonded or are coated with resin having water repellency. Thermoplastic resin, such as a tetrafluoroethylene resin and a polypropylene resin, or thermosetting resin such as an epoxy resin is used for coating. In this way, the resin is used in the process of making concrete structures or concrete products, it is made unnecessary that the form is coated with a release agent, and the releasability of the form also can be surely kept.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel mold for concrete used in the manufacturing process of concrete structures and concrete products. More specifically, the present invention relates to a steel mold for concrete which does not require application of a release agent to the mold and has excellent releasability.

[0002]

2. Description of the Related Art Conventionally, the production of concrete structures and concrete products has been
Applying a release agent to the form, pouring concrete,
After curing, it consists of a manufacturing cycle that has four steps of demolding the mold and cleaning the mold.

In this process, a release agent containing mineral oil as a main component is generally used as the release agent. However, in the process, the releasability is not sufficient, and part of the concrete is often attached to the formwork, which requires labor for cleaning the formwork.

Further, the oily substance used as a stripping agent causes oil stains on concrete, resulting in deterioration of the quality of concrete structures.

[0005]

The inventors of the present invention have completed the present invention as a result of intensive studies in view of the above problems.

That is, the present invention relates to a steel mold for concrete, characterized in that the mold surface in contact with concrete has a saw-toothed cross section and is resin-coated.

By using the formwork of the present invention, it is not necessary to apply a release agent to the formwork and to clean the formwork in the conventional manufacturing process, and the surface of the hardened concrete is free of oil stains and air bubbles and has a beautiful appearance. It has excellent properties.

By coating the surface of the mold with a water-repellent resin as in the present invention and forming a sawtooth cross section, the concrete becomes line-bonded or point-bonded, and the releasability is extremely excellent, and the mold stains are removed. It will be resolved. Moreover, the surface of the mold is less damaged, and the durability of the mold itself is improved.

In the present invention, when the distance between adjacent vertices of saw-toothed teeth is about 0.1 to 3.0 mm, the releasability is excellent, and when it is less than 0.1 mm, the adhesive surface is large and the releasability tends to decrease. Becomes Further, when it exceeds 3.0 mm, concrete enters the sawtooth-shaped mold surface and the concrete surface has a sawtooth pattern, which is not preferable.

The distance between the saw teeth is preferably about 0.1 to 3.0 mm in the resin coated state, and the angle of the saw tooth shape is not limited.

Further, the carved depth of the sawtooth shape is 0.1 to 5.
When it is less than 0.1 mm, the peelability tends to decrease. On the other hand, if it exceeds 5.0 mm, a large member thickness is required for the mold, which is expensive in terms of manufacturing, which is not practical.

The resin to be coated in the present invention may be a water-repellent resin composition, and is not limited, but thermoplastic resins and / or thermosetting resins are preferably used. As an example, as the thermoplastic resin, polypropylene resin, polyethylene resin, polystyrene resin, nylon resin, polyvinyl chloride resin, acrylonitrile resin, etc., and binary to ternary polymerization type thermoplastic resins containing these may be mentioned. Examples of the curable resin include thermosetting resins such as epoxy resin, unsaturated polyester resin and urethane resin.

The resin most preferably used in the present invention is a tetrafluoride resin. As an example, tetrafluoroethylene resin (PTFE), tetrafluoroethylene / hexafluoropropylene copolymer resin (FEP), tetrafluoroethylene /
Perfluoroalkyl vinyl ether copolymer resin (PF
A), ethylene tetrafluoride / ethylene copolymer resin (ETF
E) and the like.

The resin coating method is not limited to any method such as welding, spray welding, post-application welding, sticking, and coating.

The resin coating thickness is preferably about 0.1 to 3 mm. If it is less than 0.1 mm, it is not preferable because it is durable in repeated use, and if it exceeds 3 mm, it is expensive in terms of cost. The coating thickness is not particularly limited, but about 0.2 to 1 mm is particularly preferably used.

The mold of the present invention is one in which a steel mold is cut into a sawtooth shape in advance and coated with a water-repellent resin, and the manufacturing method is not limited, and the sawtooth shape is not limited. Also, any of vertical shape, horizontal shape, diagonal shape (concrete and line adhesion), or a mixture of sawtooth shapes (concrete and point adhesion) may be used.

The formwork of the present invention is used for producing a structure using a hydraulic material containing cement as a main raw material, that is, a concrete structure. The concrete structure, the production method, the type of concrete, and the physical properties. Etc. are not limited.

By using the formwork of the present invention for the production of concrete products having a fast production cycle by steam curing, autoclave curing, etc., the effect of rationalizing the production process is particularly great.

In using the formwork of the present invention,
A release agent may be applied, and the method of use is not limited at all, as in the case of using an ordinary mold.

[0020]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 10 and Comparative Examples 1 to 10 The shapes of the molds used in the examples are shown in FIG. Inner size, vertical 10
An inner surface A of a prismatic formwork having a size of 0 mm, a width of 200 mm and a height of 400 mm was laterally cut in a saw-tooth shape and an inner surface B was cross-cut in a saw-tooth shape. As a comparative example, the inner surface C was coated with a release agent (4.6 machine oil), and the inner surface D was in a state without a release agent.

Evaluation Method The concrete materials shown in Table 1 were kneaded with a forced twin-screw mixer (SD-55 manufactured by Taihei Koki Co., Ltd.) for 150 seconds to produce concrete. The concrete was put into a mold and the mold was removed after 3 days, and the peelability and the surface condition of the concrete were observed. Table 2 shows the coating resins on the sawtooth surface, the spacing between the sawtooth shapes, the depth of the sawtooth shape and the evaluation results. The sawtooth-shaped intervals and the sawtooth-shaped depths represent the intervals shown in FIG. The thickness of the coating resin was 0.2 mm on average.

[0023]

[Table 1]

[0024]

[Table 2]

Note) Evaluation of releasability ◎… There is no adhered matter on the mold ○… There is a slight adhered matter △… There is a thin adhered material on the whole ×… A lot of adhered matter and it is difficult to remove the mold Surface condition evaluation ◎… There are almost no bubbles, and the aesthetics are good. ○… There are a few bubbles. △… There are bubbles and voids.

[0026]

EFFECTS OF THE INVENTION By using the formwork of the present invention, the steps of applying a release agent and cleaning the formwork are omitted, so that the rationalization of the production of concrete structures is dramatically improved. . Furthermore, because the aesthetic appearance of the concrete surface is improved, it is expected that repairing and finishing processes will be omitted, and further rationalization is expected.

[Brief description of drawings]

FIG. 1 is a sketch drawing of a prismatic formwork used in Examples, and A
It is a figure which shows the cut state of surface B and surface B.

FIG. 2 is a diagram showing a sawtooth shape on a cross section A surface of a mold used in Examples.

FIG. 3 is a view showing a saw-tooth shape on a B-plane cross section of a mold used in Examples.

[Explanation of symbols]

 1 interval 2 depth

Claims (6)

[Claims] 1. The cross section of the mold surface in contact with concrete is
A steel formwork for concrete, which has a saw-tooth shape and is resin-coated. 2. The distance between the adjacent vertices of the saw-toothed teeth is 0.1 to 3.0 mm, and the carved depth of the sawtooth is
The steel formwork for concrete according to claim 1, which is 0.1 to 5.0 mm. 3. The steel formwork for concrete according to claim 1, wherein the resin to be coated is a thermoplastic resin and / or a thermosetting resin. 4. The steel formwork for concrete according to claim 1, wherein the resin to be coated is a tetrafluoride resin. 5. The steel formwork for concrete according to any one of claims 1 to 4, which is used for manufacturing a concrete structure. 6. The steel formwork for concrete according to claim 1, which is used for producing a concrete product.