JPS61205683A - Cement product - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Method] The present invention applies a glaze to an ultra-high strength cement base material consisting of a cementitious material, ultrafine powder, a high performance water reducing agent, water and aggregate,
This invention relates to a cement product characterized in that a glaze is fused onto its surface by firing.

[Prior art]

One way to give cement products a glazed finish similar to ceramics is to apply a low-temperature glaze such as phosphoric acid-based frit glaze or a frit glaze used for regular tiles, then fire it and fuse it to the surface of the cement product. Are known. In a normal cement hardened body, C* at around 450℃
(It is known that a dehydration reaction involving OH occurs, resulting in a significant drop in mechanical strength. Therefore, a method of rehydrating the fired product (4I Kaisho 52-121019)
is considered. This method requires a complicated process, and even after rehydration, the mechanical strength is not sufficient, and it is possible to make larger products than conventional ceramics. I couldn't make full use of my features. As a way to compensate for this drawback, 50Kpf
/cd or more press forming method (Japanese Unexamined Patent Publication No. 54-4
1916) has been devised, but it has the disadvantage that the process is complicated, it is not optimal as a method for manufacturing large products, and it is difficult to easily obtain uniform products.

Therefore, there is a strong need for the development of a cement product that has excellent mechanical strength and can be glazed on its surface by a simple and ordinary molding method.

[Problem that the invention seeks to solve]

In view of the above, the inventors of the present invention have conducted various tests and found that an ultra-high strength cement base material made of cementitious material, ultrafine powder, high performance water reducing agent, water and aggregate is glazed and fired. By doing so, it became possible to obtain a glazed cement product with excellent mechanical strength even by a normal pouring method, and the present invention was completed.

[Means for solving problems]

The present invention relates to a cement product characterized by being made by glazing a cement base material consisting of a cementitious material, ultrafine powder, a high performance water reducing agent, water and aggregate.

The present invention will be explained in detail below.

The cementitious material used in the present invention generally includes various Portland cements such as ordinary, early-strength, ultra-early-strength, white or sulfate-resistant cement, as well as mixed cements containing blast furnace slag, fly ash, and the like. However, in the case of mixed cement, the reaction continues for a long period of time in the general curing method, which is not preferable in terms of stability, and it is necessary to use high temperature curing etc. to accelerate the reaction. Also,
Furthermore, it is also possible to use a high-strength gypsum-based admixture, such as expansion cement to compensate for shrinkage, rapid hardening cement to develop the required strength in a short time), and gypsum-based high-strength admixtures.

The expanding component of the expanding cement is ettringite type, such as Denki Kagaku Kogyo's cracking product name "c s h+".
204, or calcined CaO, which is calcined at 1100 to 1300°C and has an average crystal diameter of 10
A value of μ or less is preferable.

The quick-hardening component of quick-hardening cement is preferably calcium aluminate-based, such as alumina cement, a combination of alumina cement and gypsum, and electrochemical cement.
The dehiscence product name ``Denkami β 4'' and the product name ``Jet □ Cement'' manufactured by Onoda Cement ■ are used.

The high-strength admixture may be a gypsum-based material, such as "Denka Σ-1000J" manufactured by Denki Kagaku Kogyo Co., Ltd., "Asano Super Mix" manufactured by Nippon Cement Corporation, etc., and the like.

The ultrafine powder has an average particle size that is at least one order of magnitude lower than that of the above-mentioned cementitious material, and it is particularly preferable to have an average particle diameter of two orders of magnitude lower from the viewpoint of flow characteristics of the mixed material. Specifically, silica dust (silica fume) is produced as a by-product during the production of silicon, silicon-containing alloys, and zirconia.
Calcium carbonate, siliceous dust, and calcium carbonate are particularly suitable.
Silica gel, opalescent silica, fly ash, slag, titanium oxide, aluminum oxide, etc. can also be used. In particular, the use of ultrafine powder obtained by pulverizing opalescent silica, fly ash, or slag using a jet mill equipped with a classifier is effective in improving curing shrinkage.

The amount of ultrafine powder used is preferably 40 to 5 parts by weight, more preferably 6 to 95 parts by weight of the cementitious material.
35 to 10 parts by weight for 5 to 90 parts by weight. This is Okibe. 5
If the amount is less than 40 parts by weight, the effect of developing high strength will be small;
If the amount exceeds 1 part by weight, the fluidity of the mixed wire material will be significantly reduced, making it difficult to mold the material and resulting in insufficient strength development.

The high performance water reducing agent used in the present invention is a surfactant with a large dispersion ability that does not cause too much delay in setting or excessive air entrainment even when added to cement in large quantities. , melamine sulfonic acid formaldehyde condensate salt, high molecular weight trigenin sulfonate, polycarboxylate etc.'
Things can be given. Conventionally, the amount of high-performance water reducing agent used is 0.3 to 1 F-IS as a solid content for cementitious materials, but in the present invention, it is preferable to add a larger amount than that. It's what you need to get better
If it exceeds 5.10 parts by weight, it will adversely affect the curing reaction.

Even if the ultrafine powder ratio is 25% or less, a fluid mixed material that can be molded by conventional methods can be obtained.

The water used in the present invention is necessary for molding, and in order to obtain a high-strength hardened product, it is sufficient to use as little water as possible.
It is preferably 5 to 30 parts by weight, and more preferably 15 to 28 parts by weight. If the amount of water is more than 30 parts by weight, it will be difficult to obtain a high-strength cured product, and if it is less than 12.5 parts by weight, it will be difficult to mold by ordinary pouring or the like. In addition, in compression molding, etc., it is not limited to this, and molding is possible even when the amount is less than 12.5 parts by weight. Also,
Extrusion molding, centrifugal molding, etc., which are normally used in the production of cement products, can also be used.

The aggregate may be one conventionally used when mixing general concrete, but it must be very hard, with a Mohs hardness of 6 or more, preferably 7 or more, or a Knoop indenter hardness of 700 or more. More preferably 800 Kf/
Use of materials selected based on any of the criteria above lIj is effective in significantly improving strength. Examples of materials that meet this standard include silica, emey-1 pyrite, magnetite, yellow jade, lawsonite, corundum, zenasite, spinel, beryl, full-cut stone, tourmaline, granite, andalusite, cross stone, Zircon, calcined bauxite, boron carbide,
Examples include tungsten carbide, ferrosilicon nitride, silicon nitride, fused silica, fused magnesia, silicon carbide, and cubic boron nitride.

The amount of aggregate added varies depending on the molding method, but for example, in the case of a pouring method, it is preferably up to about 500 parts by weight per 100 parts by weight of the cementitious material.

Furthermore, since it involves a firing process, it is preferable to use hard and fire-resistant aggregates. These aggregates include chamotte, which is normally used for monolithic refractories)
In addition, crushed ceramics can be used. This is made by pulverizing ceramics to a predetermined particle size.It is especially economical to crush defective products in ceramic factories, but pulverized ceramics that have been fired for the purpose of making aggregates can also be used. be. The particle size may be adjusted depending on the purpose and is not particularly limited.

Here, ceramics include porcelain, earthenware, porcelain, and earthenware, but from the viewpoint of mechanical strength, those classified as ordinary porcelain, earthenware, and V-ware are preferable. Examples of porcelain include:
° ゛There are hard porcelains such as high-class tableware, high-pressure insulators, and laboratory tools, as well as examples, tableware, architectural tilesΦ arts and crafts, etc., and as a strainer, there are pump parts, reaction tubes, ceramic tubes, drain pipes, and 9 exterior tiles. It is possible to obtain the desired aggregate by crushing the defective products produced at the factories that manufacture them. Of course, in order to obtain the desired aggregate from the beginning, it is also possible to perform firing and pulverization in the same way as ceramics. That is, after molding and drying, a mixture of mainly clay, quartz, feldspar, pottery stone, etc.
A method of fully baking at a high temperature of about 50℃ until a part of it melts, or a method of blending quartz, pottery stone, waxite, and a small amount of feldspathic raw materials, and a temperature of 1.200 to 1.300℃ or higher. 1,200 m
~1.3: It is also possible to obtain the desired aggregate by crushing the lumps obtained by the method of baking at about 00℃, and in this case, the glaze can also be obtained by firing twice. It can also be used.

Note that crushed products such as special ceramics such as cordierite, zirconia fist zircon porcelain, Richa porcelain, and steatite porcelain can also be used.

In addition to the above-mentioned combinations, it is possible to mix various fibers and nets, and since a firing process is involved, it is necessary to use glume fibers with excellent heat resistance. There are various natural and synthetic mineral fibers such as steel fiber, stainless steel fiber, asbestos and alumina fiber, and carbon fiber.In addition, it is also possible to use steel rods, etc.The methods for mixing and crossing the above materials are as follows. Any method may be used as long as uniform mixing and kneading can be achieved, and the order of addition is not particularly limited.

Various curing methods are possible for curing the molded product, including room temperature curing,
Any of the methods of normal pressure steam curing, high temperature and high pressure curing, and high temperature curing can be employed, and if necessary, a combination of these methods can be used to obtain an ultra-high strength cement base material.

In the above method, 1. The obtained ultra-high strength cement base material is preheated at about 100°C, then glazed, pre-dried and then fired at about 500°C to 950°C. The ultra-high-strength cement hardened body, which is the base material of the present invention, is difficult to calcinate because the ultrafine powder contained in its composition reacts with the calcium hydroxide liberated with the use of water from cement and consumes the free calcium hydroxide. It is presumed that there is no decrease in strength during the process.

In addition, the glazes applied to the surface include low-temperature glazes such as phosphoric acid-based frits and frit glazes used for regular tiles, as well as small amounts of kaolin, clay, natural mineral fine powder, pigments, etc. and use it.

As described above, a glazed and fired high-strength cement product can be rehydrated, and the curing method may be one that is normally used for curing cement.

Cement products obtained by this method can be used not only for building materials such as exterior and interior materials, but also as interior decorations, furniture, vases, works of art, and molds with modified surface properties. It is.

〔Example〕

The present invention will be explained below with reference to Examples.

Reference example l Items discharged as defective at a ceramic factory that manufactures various types of ceramics are crushed using a crusher to a size of 1.2 m or less, and then crushed using a Shiomuni mixer (with the composition shown in Table 1).
A high-strength cement base material was obtained by kneading with Chiyoda Giken m>. At that time, after curing at 20° C. and 80° RH for 1 day, curing at 50° C. in humid air was performed for 3 days.

Note that Experiment A1 is a comparative example, and Experiment 2.3 is included in the present invention.

Table-1 Cement: White Portland cement (manufactured by Chichibu Cement Co., Ltd.) Ultrafine powder: Silica hume (manufactured by Nippon Heavy Industries, Ltd.) High-performance water reducing agent: β-naphthalene sulfonate formalin a compound based Cellflow 110P (manufactured by Dai-Kogyo Seiyaku Co., Ltd.) Bone Material: Crushed ceramic product 1.2 wm or less Water:
Tap water example 1 A sample of 300 x 500 x 10 was prepared according to the formulation of the reference example, and after 3 days in a humid air at 20°C, a 10 x 20 sample was prepared (Asahi Glass).
A mixture of 100 parts by weight of a mixture of K pigment Red Garla (manufactured by K. Co., Ltd.) and 100 parts by weight of an aqueous solution of dimethyl cellulose was applied to the substrate, dried at 100°C, and then baked at 700°C and 900°C for 20 minutes. , the glaze was fused and the bending strength was measured.

As a result, at 700°C, 172 Kff, -1900
At ℃, an intensity of 161 KgfA was obtained.

Incidentally, the bending strength when the product fired at vi00°C was rehydrated was: Mayu Kqf /CI4.

The span of the test was 80 m5, and the bending test was conducted using Tensilon manufactured by Toyo Baldwin.

Example 2 300×500×1 obtained with the same formulation as Example 1
Frit 100 with the composition shown in Table 2 on a 000m panel
1 part of borax and 3 parts of Coo.2.44 o pigment were mixed into the powder, and this was adjusted with 100 parts of an aqueous solution of 2-thimethyl cellulose (hi Metrose 8H-9000 manufactured by Shin-Etsu Chemical) and applied at 200°C. After drying for 1 hour, at 550℃ for 10
After heating for a few minutes, a beautiful blue surface was obtained.

〔Effect of the invention〕

As described above, it was possible to obtain a fused cement product by applying a glaze to an ultra-high strength cement base material and firing it.

Claims (1)

[Claims] 1) A cement product characterized by being made by glazing an ultra-high-strength cement base material consisting of a cementitious material, ultrafine powder, a high-performance water reducing agent, water, and aggregate.