JP2700179B2 - Manufacturing method of enamel concrete board - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing an enameled concrete plate which is attached to a wall or a pillar to improve the appearance of the surface.

"Conventional technology" Generally, a material obtained by fusing vitreous material to a metal surface is called an enamel. The enamel has a smooth surface with high hardness formed on the surface, so it has excellent aesthetics and durability. Is also excellent.

Recently, enamel concrete using a concrete substrate has been considered as a base material of an enamel having such excellent characteristics. Japanese Patent Application No. 59-281797 and Japanese Patent Application No. No. 59-281798, “Concrete material for surface enamelling”, Japanese Patent Application No. 59-281798
No. 281799 has been filed for a method for producing a concrete material for surface enamelling.

And it is considered that such an enamel concrete is mainly used as a building material. For example, it is considered that the aesthetic appearance of a wall or a pillar is improved by using it as a panel material for attaching a wall or a pillar. .

[Problems to be Solved by the Invention] By the way, when producing the above-mentioned enamel concrete, when the glaze is fused to the surface of the base material, 600 to 9
Since it is necessary to heat at a high temperature of 00 ° C., the concrete material as the base material is also fired at a temperature of 600 to 900 ° C. However, when a temperature of 600 to 900 ° C. is applied to a concrete material using ordinary ordinary Portland cement, dehydration and thermal decomposition of the cement concrete hydrate occur, so that when the above-mentioned enamel concrete is fired, As the cocrete material expands and contracts, the concrete exposed to high temperatures expands and breaks after cooling or during the cooling process, causing delamination between the concrete and the enamel layer. There is a problem that cracks occur in

For this reason, an industrial technology for producing such enamel concrete in large quantities, and preparing each product to a predetermined quality or more, has not yet been established, and in particular, those having curved surfaces are slightly produced as works of art. It was only.

The present invention has been made in view of the above circumstances, and prevents the enamel layer from peeling, cracking, and the like, and industrially manufacture enamel concrete formed into a circular arc plate shape useful as a building material with a predetermined quality or more. It is intended to be.

[Means for Solving the Problems] The method for producing an enamel concrete plate of the present invention comprises forming a cement concrete hydrate into a cylindrical shape and forming two or more grooves extending in a direction parallel to an axis on an outer peripheral surface thereof. In advance, after the concrete molded body is calcined at a temperature higher than a predetermined firing temperature to generate cracks along the grooves, a glaze is applied to the outer peripheral surface of the concrete molded body, and By firing at the firing temperature, the concrete molded body is divided into a plurality of arc plates by the cracks, and a plurality of arc plate-shaped enamel concrete plates are manufactured.

"Action" In the method for producing a hollow concrete board of the present invention, for example, ordinary Portland cement is used as a main component of cement concrete hydrate, and the firing temperature is set to 80.
When the temperature is set to 0 ° C., the concrete molded body made of the cement concrete hydrate is calcined in advance at a temperature higher than the firing temperature of about 850 ° C., for example.

In this case, when the above-mentioned concrete compact is heated, the cement concrete hydrate changes as follows as the heating temperature increases. That is, when the temperature is around 105 ° C, the free water in the cement concrete hydrate is completely lost, and at 500-580 ° C,
Ca (CH) ₂ is decomposed to CaO [Ca (OH) ₂ → CaO + H ₂
O], dewatered, and most of the chemically bound water is lost by about 700 ° C., and the cement concrete hydrate shrinks considerably. Then, when the temperature reaches about 750 ° C., decomposition of CaCO ₃ starts, and at 825 ° C., the cement concrete hydrate sinters to become a cement clinker.

In this way, all the volatile components that can be volatilized from the concrete molded body at the sintering temperature or lower are volatilized, and the concrete molded body is sintered. Thereafter, the surface of the concrete molded body is coated with a glaze. Is applied and fired at the sintering temperature.

Here, the reason why the heating temperature during the preliminary firing is set higher than the firing temperature during the main firing will be described.

Some cement components (especially Ca content) generate various gases at each temperature when exposed to high temperatures. And
If gas is generated during firing, the glaze surface will be boiled, so that there is a problem that a beautiful finished surface cannot be obtained. Therefore, in the method for manufacturing a hollow enamel concrete plate of the present invention, by making the heating temperature during pre-baking higher than the firing temperature during main firing, a gas generated from the concrete at least at or below the firing temperature during main firing, that is, All the volatile components in the concrete are volatilized at the calcining stage. Then, since the concrete molded body calcined at a temperature higher than that at the time of firing is out of gas at the stage of calcining, no gas is generated at the firing temperature at the time of firing, and therefore, When the glaze on the concrete surface is fired at the firing temperature, a beautiful enamel surface is obtained.

For this reason, when the enamel concrete plate is manufactured as described above, peeling of the enamel layer on the concrete surface, generation of cracks, etc. are prevented, and the glaze is a volatile component from the cement concrete hydrate. The enamel layer is not deteriorated due to the compounding, whereby the enamel layer having an excellent appearance is formed, and the enamel concrete plate having a good appearance can be obtained.

Further, in the method for producing an enamel concrete plate of the present invention, a cement concrete hydrate is formed into a cylindrical shape, and two or more grooves extending in a direction parallel to an axis are formed on the outer peripheral surface thereof. By calcining the concrete molded body at a temperature higher than a predetermined sintering temperature, all volatile components that can be volatilized at a predetermined sintering temperature or lower are volatilized from the concrete molded body, and the concrete molded body is calcined. At the same time, cracks are formed along the grooves at the same time.

Then, after doing this, glaze is applied to the outer peripheral surface of the cocrete molded body, and the concrete molded body is divided into a plurality of arc plates by cracks in the respective grooves by firing this at the firing temperature, Manufacture a plurality of arcuate plate-shaped enamel concrete plates. In this case, since the concrete compact shrinks uniformly in the circumferential direction when the glaze is fused, when the arc plates divided by the cracks are again fitted into a cylindrical shape, both ends of each arc plate are formed. Will be exactly butted as before, and since there will be no distortion of the concrete molding,
An enameled concrete plate formed into a desired arc plate shape with high accuracy can be obtained. In addition, the enamel layer on the surface does not peel, crack, etc. does not occur, and the glaze does not combine with the volatile component from the cement concrete hydrate to deteriorate the enamel layer. An excellent enamel layer is formed, whereby an enamel concrete plate having excellent appearance and high dimensional accuracy can be obtained.

"Example" Hereinafter, as one example of the present invention, a method for manufacturing an arcuate plate-shaped enamel concrete plate will be described with reference to Figs. 1 to 3.

The manufacturing method of the enamel concrete plate of this embodiment is as follows.
It is applied when manufacturing an arcuate plate-shaped enamel concrete plate attached to a large number of circular columns provided in a station such as a subway, and forms cement concrete hydrate into a cylindrical shape. After forming two or more grooves extending in a direction parallel to the axis on the outer peripheral surface, and then calcining the molded body at a temperature higher than a predetermined firing temperature to cause cracks along the grooves, A glaze is applied to the outer peripheral surface of the formed body, and the formed body is baked at the firing temperature to divide the formed body into a plurality of arc plates by the cracks, thereby producing a plurality of arc plate-shaped enamel concrete plates. Things.

The above-mentioned cement concrete hydrate is usually obtained by kneading Portland cement with water and aggregate. As a concrete base material used as a base material in the enamel concrete plate of this embodiment, potassium titanate whisker or the like is used. The ceramic fiber of 2 to 15% by weight based on the total amount of the concrete base material may be used to improve the dimensional stability at high temperatures.
In the above concrete base material, a glaze for forming an enamel layer or a glaze having a similar composition is added to the concrete base material in an amount of 0.
By mixing 5 to 7% by weight, a part of the glaze can be dispersed in the concrete base material, thereby improving the adhesion between the enamel and the concrete base material. As the aggregate to be mixed into the concrete base material, a fired product (particle size: 2 to 15 mm) such as a crushed product of ceramics or chamotte brick may be used instead of the conventional aggregate. By mixing as an aggregate a calcined product about twice the weight of ordinary Portland cement as above, the volume change (expansion in proportion to the heating temperature) and explosion (heating temperature of 900 ° C) that occur in ordinary aggregates
The above case) can be prevented. In this case, for example, even after heating to 900 ° C., 130 kgf /
Residual strength of not less than cm ² can be secured, and it can be used as a structural material.

In the above-mentioned concrete base material, a specially modified water-soluble phenol resin or pitch coke exhibiting a strong bonding force at a high temperature may be added in an amount of 3 to 20% by weight based on the total amount of the concrete base material. Thus, a concrete base material capable of maintaining high strength even when exposed to high temperatures can be obtained. Further, in the concrete substrate, strength can be significantly improved by mixing 2 to 20% by volume of inorganic fibers such as carbon fiber and silicon carbide fiber and steel fiber with respect to the total amount of the concrete substrate, In such a case, even when continuous molding is performed by an extruder, extrusion can be easily performed, and cutting and molding performed in post-processing can also be easily performed.

The glaze is mainly composed of silicon dioxide, boron oxide, sodium oxide, aluminum oxide, potassium oxide, and the like. Feldspar, silica stone, borax, soda lime,
Main materials such as Chile saltpeter (NaNO ₃ ) and fluorite (CaF ₂ ) are once melted and then cooled to form a glass, which is finely pulverized to form a frit. When such a glaze is used, water or glue may be added and then applied to the surface of the concrete base material. In addition, an inorganic coloring agent composed of a metal oxide may be added to the glaze, if necessary. In this case, an enameled concrete plate excellent in aesthetic appearance of various colors can be obtained.

Next, a method for producing an arcuate plate-shaped enamel concrete plate will be described in detail.

When manufacturing this enamel concrete board, first, for example, 100 parts by weight of ordinary Portland cement is mixed with 200 parts by weight of a crushed ceramic product (particle size: 2 to 15 mm) as an aggregate and kneaded to obtain a concrete base. Prepare the ingredients. After this, as shown in FIG. 1, the concrete substrate is formed into a cylindrical shape by centrifugal molding, and two grooves 1, 1 extending in a direction parallel to the axis are formed on the outer peripheral surface thereof. Is cured for a predetermined period to produce a concrete molded body 2.

Next, as shown in FIG. 2, a ring-shaped stainless steel (SUS303 or the like) tag 3 is formed on the outer peripheral surface of the concrete molded body 2 according to the length of the concrete molded body 2. One or more (two in the figure) and then put the concrete compact 2 into a heating furnace
Heat at a calcining temperature of about 1000 ° C. for a predetermined time. At this time, if the firing temperature is set to, for example, 800 ° C., the calcining temperature is set to a temperature higher than the firing temperature, for example, about 850 to 1000 ° C.

When the concrete molded body 2 is heated in this manner, the cement concrete hydrate in the concrete molded body 2 changes as the heating temperature increases, that is, when the temperature is around 105 ° C. lost freedom completely cement concrete hydrate, at 500 to 580 ° C., cement concrete hydrate of Ca (OH) ₂ CaO next to decomposition _{[Ca (OH) 2 → CaO +} H 2 O ], Dehydrated, an additional 700
Most of the chemically bound water is lost by about ° C., and the concrete molded body 2 shrinks considerably. When the temperature reaches about 750 ° C., decomposition of CaCO ₃ starts, and at 825 ° C., the concrete molded body 2 sinters.

Then, by pre-baking the concrete molded body 2 at a temperature higher than a predetermined firing temperature in this manner, all volatile components that can be volatilized at the sintering temperature or lower from the concrete molded body 2 are volatilized. And the concrete molded body 2 is sintered together,
A crack is formed along 1.

After the calcination is performed on the concrete molded body 2 in this manner, the tag 3 is removed from the concrete molded body 2, and then the glaze having the same composition as the glaze added to the concrete base material is added. A certain amount of water is added to a glaze obtained by adding a coloring agent to the surface of the concrete molded body 2, and the resultant is applied to the outer peripheral surface of the concrete molded body 2 by brushing or the like, and then left for a certain period of time to remove moisture. in this case,
The glaze is applied in a predetermined thickness with a thickness of the finished enamel being 0.5 to 0.7 mm as a guide. At this time, the glaze is not applied to the bottom of the groove 2 as shown in FIG. It is desirable to apply in a range that covers the edge.

After this, the concrete molded body 2 is put into the heating furnace again, and the temperature in the furnace is raised until the glaze melts (for example, 800 ° C.) for a certain period of time, and the temperature is maintained for a certain period of time to melt the glaze. After confirming that the surface of the concrete molded body 2 has become smooth, it is gradually cooled at a fixed rate. In this way, the concrete molded body 2 is divided into two arc plates by the cracks in the grooves 1 and 1, and two arc plate-shaped enamel concrete plates are formed at the same time.

When the enamel concrete board is manufactured in this manner, the concrete molded body 2 is melted when the glaze is fused.
Is not shrunk, and the concrete molded body 2 is not distorted. Thus, a desired arc-shaped enameled concrete plate can be obtained with high accuracy. In addition, the enamel layer on the surface does not peel, crack, etc. does not occur, and the glaze does not combine with the volatile component from the cement concrete hydrate to deteriorate the enamel layer. An excellent enamel layer is formed, whereby an enamel concrete plate having excellent appearance and high dimensional accuracy can be obtained.

The enameled concrete plate manufactured in this manner is attached to the surface of a circular pillar provided in an underground station or the like so as to form a circumference in pairs, and the enameled concrete is further adjoined. By providing joints at the joints formed at the joints of the plates, a surface having excellent appearance is formed on the surface of the column. In this case, the joint at the joint corresponding to the groove 1 of the concrete molded body 2 is a vertical joint, but the joint at the upper and lower joints of each arc plate is a joint width of 2-3 mm in width or joints. No thrust.

In this embodiment, a method of manufacturing an arcuate plate-shaped enameled concrete plate has been described. However, in the case of manufacturing an enameled concrete plate having such a shape, a concrete substrate is formed by a mold having a desired shape. In that case, at the time of calcination, deformation may be suppressed during heating by placing the mold in a heating furnace and heating as necessary.

[Effect of the Invention] According to the method for manufacturing an enamel concrete plate of the present invention, cement concrete hydrate is formed into a cylindrical shape, and two or more grooves extending in a direction parallel to the axis are formed on the outer peripheral surface thereof. Then, after the concrete molded body is calcined at a temperature higher than a predetermined firing temperature to cause cracks along the grooves, a glaze is applied to an outer peripheral surface of the concrete molded body, and the resultant is fired. By sintering at a temperature, the concrete molded body is divided into a plurality of cylindrical plates by the cracks, and a plurality of arcuate plate-shaped enamel concrete plates are manufactured, so that the concrete molded body does not shrink when the glaze is fused. In addition, since the concrete molded body is not distorted, the enameled concrete plate formed into a desired arc-shaped plate with high accuracy. Can be obtained. In addition, the enamel layer on the surface does not peel, crack, etc. does not occur, and the glaze does not combine with the volatile component from the cement concrete hydrate to deteriorate the enamel layer. An excellent enamel layer can be formed, whereby an enamel concrete plate having excellent appearance and high dimensional accuracy can be obtained.

For this reason, according to this method for manufacturing an enameled concrete plate, an arcuate plate-shaped enameled concrete plate useful as a building material, such as a decorative material attached to the surface of a circular pillar provided in an underground station yard or the like, is used. , And can be industrially manufactured with a predetermined quality or higher.

[Brief description of the drawings]

1 to 3 are views showing an embodiment of the present invention. FIG. 1 is an external view of a cylindrical concrete molded product,
FIG. 2 is an external view of a state in which a tag is attached to a concrete molding, and FIG. 3 is a cross-sectional view showing an application range of glaze. 1 ... groove, 2 ... concrete molding, 3 ... tag, 4 ... glaze.

Claims (1)

(57) [Claims] 1. A cement concrete hydrate is formed into a cylindrical shape, and at least two grooves extending in a direction parallel to an axis are formed on an outer peripheral surface thereof. After calcining at a high temperature to cause a crack along the groove, a glaze is applied to the outer peripheral surface of the concrete molded body, and the resultant is fired at the firing temperature to crack the concrete molded body. The method for producing an enameled concrete plate, comprising: dividing the enameled concrete plate into a plurality of arcuate plates to produce a plurality of arcuate plate-shaped enameled concrete plates.