JPH0466161B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a concrete shaped article having a complex surface shape.

[Conventional technology]

Normally, the manufacturing method for concrete products is to first make a steel or wooden formwork with the inverted shape of the desired product, then pour concrete into this formwork, and apply vibration, centrifugal force, and press force to the formwork. Compaction is performed by either one or a combination of these,
This was generally cured by natural curing, steam curing, underwater curing, or a combination of these, and then demolded and manufactured into a product.

In addition, when attempting to manufacture a concrete model with a particularly complex surface shape, one of the above manufacturing methods is to form a formwork with the inverted shape of the required product using materials such as resin, rubber, or styrofoam. They also adopted a manufacturing method using recycled materials.

[Problem that the invention seeks to solve]

However, among the conventional manufacturing methods mentioned above, in the case of creating a steel or wooden formwork with an inverted shape of the required product, it is difficult to process it into a complex surface shape due to the material of the formwork. In particular, processing into an inverted shape is technically very difficult, and the processing cost is also very high, making it virtually impossible.

In addition, when forming the formwork from materials such as resin, rubber, or styrofoam, although it is not technically difficult, problems such as shrinkage during curing (resin, rubber) or low rigidity (rubber, styrofoam) may occur. As a result, the accuracy of reversal reproducibility (transferability) of complex surface shapes becomes extremely low. Therefore, this method can only be used for concrete structures that do not require much precision, and has the drawbacks of poor durability and poor economic efficiency for its price.

The present invention does not use an inverted formwork from the beginning as in the past, but instead manufactures a prototype of the product from a material with good workability, and then uses this prototype to obtain an inverted formwork, thereby achieving high precision concrete modeling. Its purpose is to provide a method for shaping things.

[Means for solving problems]

In order to achieve the above object, the present invention involves forming an inverted concrete formwork by pouring concrete mixed with an expanding agent into a master form made of a material with good workability such as wood, and forming an inverted concrete formwork. A method for manufacturing a concrete shaped article having a complicated surface shape, which is characterized by forming a resin layer or a ceramic or metal layer by thermal spraying on the surface of the concrete product after pouring concrete and forming the concrete product.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to the embodiments shown in FIGS. 1 and 2. In addition, FIG. 1 is a perspective view showing an example of a concrete model formed by the method of the present invention, and FIG. 2 A and B are explanatory diagrams of the same forming process.

As shown in FIG. 1, a concrete model (product) 1 to be obtained by molding has, for example, a corrugated surface 2, a rectangular shape in plan view, and a flat bottom surface. .

Next, the forming process of the above concrete product 1 will be explained with reference to A and B in Fig. 2. First, as shown in Fig. Manufactured from good materials, such as wood.

Next, this wooden model 3 is placed in a steel box 4 with its corrugated surface 2 facing up, and the surface of the model 3 is coated with a mold release agent 5 commonly used for concrete. Reinforcing reinforcing bars 6 are arranged above the master form 3, and then formwork concrete mixed with an expanding agent is poured into the steel box 4 to smooth its surface.

Since the concrete for the formwork expands when it hardens, the corrugated surface 2 of the master form 3
is transferred with high precision. And this is steel box 4
By demolding, an inverted concrete form 7 of the concrete product 1 reinforced with reinforcing bars 6 can be obtained. Here, Table 1 shows mixing examples of the above concrete for formwork.

Next, as shown in FIG. 2, the inverted concrete form 7 is placed in a steel box 8, and a release agent 9 is applied to the surface of the inverted concrete form 7. composition rebar for reinforcement (not shown)
After arranging the above, concrete for forming is poured into the steel box 8.

Then, after compacting it using vibration force, centrifugal force, press force, or a combination of these, it is placed in the steel box 8 and steam-cured as it is, and then heated to a specified temperature. If the mold is removed after a period of time, a concrete product 1 of the desired shape can be obtained, and in this example, compared to a product formed using a wooden formwork, a product with higher precision can be obtained. . In addition, Table 1 shows examples of the formulation of the above-mentioned concrete for forming.

Concrete product 1 obtained as above
Concrete itself has high vibration breathing properties and low thermal conductivity, so it has a variety of uses, but since its surface is the same as the bare concrete, it does not have wear resistance or smoothness, and is used, for example, in mechanical parts. It may not be possible to use it as such.

Therefore, in the present invention, the surface 2 of the obtained concrete product 1 is subjected to surface treatment by forming a resin layer or a ceramic or metal layer by thermal spraying to impart wear resistance and smoothness.

First, to describe the method of forming a resin layer on the surface 2 of the concrete product 1, as shown in FIG. 2B and FIG. After coating 9, an epoxy-based molten resin 10 that is easily integrated with uncured concrete is coated thereon.

Then, concrete for molding is poured with this molten resin 10 in an uncured state, and after vibration compaction, steam curing is performed in this state, and then when the mold is demolded, the resin is applied to the surface 2 of the concrete product 1. The film 10 is formed in an integrated state.

Here, as the molten resin 10, an uncured resin, for example, a mixed resin consisting of a hydrophobic epoxy resin such as bisphenol A diglycidyl ether as the main resin and an epoxy resin such as oleylamine as a curing agent, was used.

As a result, the resin film 10 is formed integrally on the surface 2 of the concrete product 1, and a product with wear resistance, particularly smoothness, and a complex surface shape sufficiently reproduced can be obtained.

Next, a method for manufacturing the product 1 shown in FIG. 4, which has smoothness and wear resistance and can sufficiently reproduce a complex surface shape, will be described in detail.

In this method, the surface 2 of the concrete product 1 is
This is a method of integrally forming a ceramic or metal layer 11 by thermal spraying, and will be explained in detail below with reference to an embodiment shown in FIG.

First, in the cutting step 12, the surface 2 of the concrete product 1 is subjected to preliminary grinding, and then in the blasting step 13, an abrasive material is applied to the surface 2 of the concrete product 1 with compressed air of about 5Kg/cm ² to 7Kg/cm ² The surface is roughened by spraying it on the surface.

Next, in a preheating step 14, the surface 2 of the concrete product 1 is heated to about 50°C to 90°C to remove moisture immediately before thermal spraying, and then in a thermal spraying step 15, thermal energy of the plasma is used to heat the surface 2 of the concrete product 1 to about 50°C to 90°C. The surface 2 of the concrete product 1 is heated by heating the powder to a molten state or a state close to it.
by spraying at high speed on the ceramic or metal layer 1.
form 1.

In this case, the above thermal spraying material is zirconia.
When magnesia (ZrO ₂ .MgO) is used, the temperature of the surface 2 of the concrete product 1 is controlled at approximately 50°C to 90°C.

Next, an example of the plasma spraying method will be explained with reference to FIG.

First, gases such as hydrogen, nitrogen, helium, argon, etc., either singly or mixed at a predetermined ratio, are continuously fed into the plasma generator 17 from the working gas supply device 16 that generates plasma. Power is supplied from the power supply device 18 to both the positive and negative electrodes provided in the device 17 to generate an arc.

Next, the gas becomes dissociated and ionized (separated into positive and negative ions), that is, becomes a plasma state, expands rapidly, and is injected from the small hole of the plasma generator 17 as a high-speed, high-temperature plasma jet.

A ceramic or metal layer can be formed by mixing a thermal spray material 19 such as ceramics or metal into this plasma jet and spraying it onto the surface 2 of the concrete product 1.

Note that the plasma generator 17 is a water circulation device 20.
It is cooled by cooling water from

Table 2 shows the composition and properties of ceramic examples suitable as the thermal spray material 18 described above. Also, the third
The table shows examples of metals suitable as the thermal spray material 19 and their properties.

As a result, the ceramic or metal layer 11 is formed integrally with the surface 2 of the concrete product 1, and a product with wear resistance and smoothness that sufficiently reproduces a complex surface shape can be obtained.

〔Effect of the invention〕

As described above, the method for manufacturing a concrete shaped object having a complex surface shape according to the present invention involves pouring concrete mixed with an expanding agent into a master mold made of an easily workable material such as wood, and forming an inverted concrete form. After forming a concrete product by pouring concrete into this inverted concrete formwork, a resin layer or a layer of ceramics or metal by thermal spraying is formed on the surface of the concrete product, so the complex surface of the original model is The shape can be accurately reproduced (transferred).

In addition, the resin layer or thermally sprayed ceramic or metal layer formed on the surface of the concrete product is in close contact with the surface of the concrete product and forms an integral structure, so there is no risk of it peeling off, and the durability is improved. Since wear resistance and smoothness are imparted, there are various effects such as the ability to obtain a product that can be used satisfactorily as a precision mechanical component.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of a concrete model formed by the method of the present invention, Fig. 2 A and B are explanatory diagrams of the forming process of the concrete model, and Fig. 3 is a concrete example of another embodiment. 4 is a perspective view of a concrete model according to another embodiment; FIG. 5 is a block diagram of a surface treatment process for the concrete model;
FIG. 6 is a block diagram of the plasma spraying process. 1... Concrete product, 2... Surface, 3...
Prototype, 4, 8... Steel box, 5, 9... Release agent, 6
...Reinforcing bars, 7...Inverted concrete formwork, 10
...Resin layer, 11...Ceramics/metal layer.

【table】

【table】

【table】

Claims (1)

[Claims] 1. Form an inverted concrete form by pouring concrete mixed with an expanding agent into a prototype made of easily workable materials such as wood. After pouring concrete into this inverted concrete form to form a concrete product, A method for producing a concrete shaped product having a complex surface shape, which comprises forming a resin layer or a ceramic or metal layer by thermal spraying on the surface of the concrete product.