JPS63297276A - Reinforced fired board - Google Patents

Abstract

PURPOSE:To contrive prevention of cracks occurring in drying and firing, by embedding an expandable and contractible reinforcing material in a fired board of a ceramic product. CONSTITUTION:This reinforced and fired board is prepared by embedding a reinforcing material expandable and contractible in at least one direction in a fired board of a ceramic product. The above-mentioned fired board is obtained by forming and firing a kneaded material consisting of an SiO2 based heat treatment product, an alkali silicate and water while heating. The aforementioned reinforcing material is selected from twisted wires, lath nets, reinforcing bars continuously bent into conical forms, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reinforced fired board. More specifically, the present invention relates to a reinforced fired board in which cracks do not occur in the fired board during drying and heating and firing because a reinforcing material that is expandable and contractible in at least one direction is embedded therein.

[Prior Art and Problems to be Solved by the Invention] Conventionally, clay has been mainly used as a raw material for ceramic products such as tableware, roof tiles, bricks, and tiles. however,
Clay requires a large amount of water for molding, so when drying it is 5 to 8
%, and the product was prone to deformation and cracking. Therefore, relatively small items such as tableware, roof tiles, bricks, tiles, etc. can be fired by controlling the heating conditions, but large items such as panels used for the exterior walls, partition walls, floors, etc. of prefabricated houses cannot be fired. was extremely difficult. In particular, when the wall thickness increases, the drying conditions between the surface layer and the middle layer of the panel become uneven, and deformation and cracks are inevitable, making it impossible to manufacture products that can be supplied to the market in terms of strength and appearance. It was possible.

Of course, it was possible to manufacture large products to a certain extent if mass production was not taken into consideration, but since it was a product production, it would be very expensive, and the battlements could not be expected to be strong. It could only be used for decorative purposes, such as by attaching small pieces of ceramic shards to the walls that had been completed, and could not be used for practical purposes at all as wall materials.

In order to solve the above problems, the present inventor has proposed 51
An attempt was made to mold a hybrid product from a heat-treated product of the 02 series, an alkali silicate, and water, and heat and sinter the resulting molded product.

However, when it comes to large products, reinforcement with reinforcing bars is required for strength, but when simply burying reinforcing bars in the fired products, the reinforcing bars cannot follow the shrinkage of the fired plates during drying and firing, so both There is a risk that stress will be generated during this time and cracks will occur on the surface of the fired product.

In view of the above-mentioned points, an object of the present invention is to provide a reinforced fired board that does not generate cracks during drying and firing.

[Means for Solving the Problems] The reinforced fired board of the present invention is a fired board obtained by molding, heating and firing a mixed material consisting of a 5IO2 heat-treated product, an alkali silicate, and water, and comprising: It is characterized by a reinforcing material that is expandable and contractible in at least one direction embedded within the fired plate.

[Example] Hereinafter, the reinforced fired plate of the present invention will be explained.

In the present invention, a 3102-based heat-treated product is used as a raw material for the fired product, but this is a broad concept that includes anything that has 5102 as its main component and is heat-treated naturally or artificially. Specific examples include naturally occurring materials such as anti-flinder, whitebait, volcanic ash, and feldspar powder, and artificially obtained materials such as chamotte, fly ash, blast furnace slag, bulb incineration ash, and sludge incineration ash. Since these 5i02-based heat-treated products are raw materials that have been heated once, they have the characteristics that shrinkage during drying and heating and firing of the molded product is small, and the fired product is unlikely to be deformed or cracked.

In particular, in the case of large-sized fired products, the drying state of the surface layer and middle layer becomes uneven, and deformation and cracks are likely to occur during heating and firing. However, when using S i 03-based heat-treated products as raw materials, such adverse effects can be avoided. It never happens.

Among the 8102 heat-treated products, fly ash has the above-mentioned deformation and crack prevention effects, and also has the following properties: 1. Alkaline silicates and alumina and especially calcium oxide in the fly ash react to form insoluble silicates. Ca
Clay + Naz 8102 → Na clay + Ca5t's) It is preferable because it produces a metal-like hard molded product.■ Alkali silicate acts as a melting agent for fly ash during firing, and it can be fired at a relatively low temperature for solidification. , ■ Fly ash itself is a fine powder, so there is no need to pulverize it for preparation, and ■ Fly ash is currently a problem in waste disposal, but it can be used effectively. It has the following advantages.

In the present invention, an alkali silicate is used as a raw material for the fired body together with the 5i02 heat-treated product. Examples of the alkali silicates include sodium silicate, potassium silicate, and lithium silicate, and these can be used in either liquid or powder form. These alkali silicates are used as molding and solidifying agents for 5102 heat-treated products;
Used as a sintering agent. When fly ash is used as the 8102 heat-treated product, it reacts with alumina and calcium oxide in the fly ash to form a hard molded product. This molded product can be cured and demolded within 60 minutes, and can be dried as well as demolded without the need for curing. This is an advantage not found in cement products or clay moldings, and is a key to increasing productivity. Furthermore, since it functions as a melting agent for fly ash during firing, it has the advantage that it can be fired at a relatively low temperature.

Among the silicic acid compounds, potassium silicate reacts well with the glaze,
The beauty of the glazed surface of the fired product is not impaired.

Alkali silicates may be used alone or in combination of two or more.

The amount used (the total amount used when two or more types are used) is preferably 3 to 35% (by weight, the same applies hereinafter) of the kneaded product, and more preferably 5 to 30%.

If the amount used is less than 3%, there is a problem that the molded product will not solidify to a strength that allows handling. on the other hand,
If the amount used exceeds 35%, the curing time will be too long (the glaze will remain agar-like (jelly-like) and will not harden), and the surface precipitation of alkali will increase, impairing the beauty of the glaze, and causing efflorescence after firing. There is.

In the fired plate of the present invention, the 8102-based heat-treated product,
Wollastonite may be added to the mixture consisting of alkali silicate and water. The following effects can be achieved by adding wollastonite.

■Since wollastonite is a acicular crystalline mineral, it has low drying shrinkage and excellent dimensional stability. Therefore, cracks are less likely to occur during drying and heating and baking, and dimensional accuracy can be significantly improved.

■Wollastonite has a small coefficient of thermal expansion and can be fired quickly, alleviating thermal stress and preventing deformation and cracking.

■ Adding wollastonite reduces firing shrinkage, making it difficult for cracks to occur. In particular, if reinforcing bars are buried, thermal stress at high temperatures can be controlled, making it even more difficult for cracks to occur.

■Since wollastonite is a acicular crystalline mineral, the elastic modulus of fired products is improved.

The amount of wollastonite used is preferably 5 to 25% of the kneaded material. If the amount used is less than 5%, the above-mentioned properties of wollastonite will not be reflected in the physical properties of the fired product.
Exceeding this is not preferable because the amount of water added increases and drying shrinkage increases, and even if more wollastonite is added, there is no change in the effect. However, if 20% or more is required, the drawback of drying shrinkage can be eliminated by calcining at 1000°C.

In the present invention, glass powder may be further added to the mixed material. In this case, the glass powder is used as a fluxing agent and does not have the function of a solidifying agent. The amount to be used is not particularly limited and may be appropriately selected in consideration of the amount of water glass added, etc. Typically,
Although the amount of sodium silicate and/or potassium silicate used is reduced to the hardening limit, it is preferable to increase the amount of glass powder used as a flux to suppress surface precipitation. Furthermore, when setting the firing temperature, it is preferable to increase the amount of glass powder used if low-temperature firing is desired.

Further, if necessary, aggregates such as feldspar, chamotte, foamed shale, foamed refractory rock, foamed clay, etc. may be added to the mixed material.

In the present invention, in order to impart the desired appearance, durability, and water resistance to the fired product, the surface of the molded product may be glazed or coated with engobe prior to heating and firing, or may be configured to do both. As the glaze, a suitable glaze such as a frit glaze or a raw glaze can be used, and the amount applied is not particularly limited. Furthermore, the coating method can be any of the commonly used methods such as spraying, pouring, and brushing. As the engobe, for example, white clay, feldspar, kaolin, a combination of these and clay, etc. may be used, but it is not limited to these. For example, 35% white clay, 3% white clay (1000℃ calcined)
A mixture consisting of 596, 25% glass powder, and 35% F220 is ground in a pot mill, CMC liquid is added to form a slurry, and the slurry is atomized, and when it is fired at 1050''C, a semi-matte reddish-brown surface is formed.

In the reinforced fired plate of the present invention, a reinforcing agent that is expandable and contractable in at least one direction is embedded in the fired plate having the above-described configuration.

In the present invention, "a reinforcing material that is stretchable in at least one direction" means that it is stretchable in the longitudinal direction in the case of a linear reinforcing material, and in at least two directions in the case of a planar reinforcing material. Reinforcement material that can be expanded and contracted in one direction. In addition, "stretchable" means that it has enough stretchability to follow the drying shrinkage of the fired plate, and is approximately 0.5mm with respect to the normal length. θ~1.
This means that it has elasticity of about 2%.

Specific examples of such reinforcing materials include stranded wires, lath nets that are continuously bent into a mountain shape (see Figure 1), reinforcing bars shaped into a sine curve (see Figure 2), and shaped into a spring shape. Examples include reinforced steel bars (see Figure 3).

In the case of the lath net shown in Fig. 1, when the fired plate shrinks in the (X) direction, the mountain-shaped waves follow the reduction and alleviate the difference in shrinkage between the lath net and the fired plate); Y)
The reduction in direction can be followed by the structure of the lath network.

The stranded wire is usually composed of two wires with a wire diameter of 3 m/m and preferably has a twist curve wavelength of 4.0 cm or less. If the wavelength is larger than 4.0ca+, there is a problem that it cannot follow the shrinkage stress of the substrate. In the case of sinusoidal reinforcing bars, the wavelength (Q) and wave height (h) of the sinusoidal curve vary depending on the thickness, size, etc. of the fired plate, but it is generally desirable that R/h be in a relationship of 2 or less. In addition, when using spring-shaped reinforcing bars, the pitch (P) of the spring and the average diameter (D) of the coil are
-D x 1.5 is preferably satisfied.

In the present invention, in addition to the above-mentioned stranded wire, lath mesh, sine curve reinforcing steel, and spring reinforcing steel, any material can be used as an auxiliary material as long as it can alleviate the shrinkage difference with the fired plate. It is possible.

The method for producing a fired product of the present invention consists of molding a kneaded product consisting of the above-mentioned SL 02 heat-treated product, an alkali silicate, and water, and heating and firing the resulting molded product. , each step will be explained in order below.

First, all the ingredients are mixed at the same time and stirred with a mixer to obtain a kneaded product. Next, the obtained kneaded material is poured into a mold of an appropriate shape. In this case, the complementary strand mentioned above,
Reinforcing materials such as reinforcing bars and lath mesh are placed in advance in the mold. Usually, demolding is performed after the kneaded material is cured for 30 to 60 minutes.

After demolding, the molded body is dried by hot air, far infrared heating, microwave heating, etc. Drying may be performed at room temperature. The time required for drying varies depending on the thickness of the molded product and the heat dehydration method, but is approximately 30 minutes to 8 hours. In short,
It is preferable to perform rapid drying so that the moisture content is approximately 2% or less.

After drying, the molded body is placed in a firing furnace and heated to a temperature of 980 to 1050.
Heat and bake at ℃ for about 4 to 6 hours. Heating) 3 degrees and heating time may be selected in consideration of the type of raw materials, the proportion of the mixture, the dimensions of the molded body, etc.

Regarding the heating speed, especially in the case of fly ash, it is important to completely burn out the contained unburned coal fine particles before the glaze melts, and it is necessary to maintain the temperature range of 500 to 700°C for a certain period of time.

Next, the reinforced fired plate of the present invention will be explained based on Examples, but the present invention is not limited to these Examples.

Examples 1 to 4 45% by weight of fly ash, 15% by weight of hardening agent (soda-based), 40% by weight of other additives, and 9% by volume of aggregate (
A mixture containing 23.9% by volume of water (outer cutting) and 23.9% by volume (outer cutting) was simultaneously stirred with a mixer for about 3 minutes to obtain a kneaded product. The obtained kneaded material was put into a test piece (120cm x 45cm x 6
cm (thickness)) was poured into a wooden formwork. The following stranded lines (Example 1) are placed in advance in the formwork.
Lath mesh (Example 2), sine curve reinforcing bars (Example 3)
Alternatively, spring-shaped reinforcing bars (Example 4) were buried.

Stranded wire; φ3ffl/m, wavelength 4.0cm lath net; 1
．． 7 x 3.0cm diamond hole lath pinch ((a) in Figure 1)
)) 4.3cLIl height (corresponds to the mountain in Figure 1)) 4.0cm sine curve reinforcing bar: φ6m/m, wavelength (fri: 28co+ (
(See Figure 2) Wave height (h): 14cm (See Figure 2) Spring reinforcing bar: φ5m/+n, pitch (P): 5 cv
(See Figure 3) Average diameter (D): 3 am (See Figure 3) The kneaded material was left to stand for 60 minutes to harden, then demolded, and then dried by microwave heating for 25 minutes. After drying,
Firing was performed in a roller kiln. After heating and baking,
It was allowed to cool naturally and was taken out of the kiln after 5 hours.

Drop impact (5kg 1m drop) for the obtained test specimen
The occurrence of cracks was measured using the method, and the bending strength was measured using a two-line load divided into four equal parts. The measurement results are shown in Table 1.

Comparative Example 1 A fired plate was produced in the same manner as in Example 1 except that ordinary reinforcing bars (6 m/mφ) were embedded instead of twisted wires.

Regarding the obtained test specimen, the occurrence of cracks and the bending strength were measured in the same manner as in Example 1.

The measurement results are shown in Table 1.

Comparative Example 2 A fired board was manufactured in the same manner as in Example 1 except that the stranded wire was not embedded.

Regarding the obtained test specimen, crack occurrence and bending strength were measured in the same manner as in Example 1.

The measurement results are shown in Table 1.

[As is clear from Table 1 below, the fired plates of the present invention are free from cracks and have a sufficient reinforcing effect.

[Effects of the Invention] As detailed above, according to the reinforced fired board of the present invention, cracks do not occur during drying and firing, a sufficient reinforcing effect can be obtained, and the fired board has an excellent appearance. It has the effect of being able to move the board.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a lath net bent into a mountain shape, which is an example of the reinforcing material used in the reinforced fired board of the present invention, and FIGS. It is an explanatory view showing reinforcing bars of. (Drawing code) (1) Nice net (2): Rebar

Claims (1)

[Scope of Claims] 1. A fired plate obtained by molding and heating and firing a kneaded product consisting of a SiO_2-based heat-treated product, an alkali silicate, and water, the fired plate having a structure that is expandable and contractible in at least one direction. A reinforced fired board characterized by having a reinforcing material buried therein. 2. The reinforced fired board according to claim 1, wherein the reinforcing material is a stranded wire. 3. The reinforced fired board according to claim 1, wherein the reinforcing material is a lath net formed by continuously bending into a mountain shape. 4. The reinforced fired board according to claim 1, wherein the reinforcing material is a reinforcing bar formed into a sine curve shape. 5. The reinforced fired board according to claim 1, wherein the reinforcing material is a reinforcing bar formed into a spring shape.