JPH0625018B2 - Manufacturing method of cement products with net reinforcement - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a cement product containing a mesh reinforcement, and more particularly to a method for obtaining a cement product having improved mechanical strength.

(Prior Art) Conventionally, cement products with high mechanical strength are available in Japanese Patent Publication No. 57-
As disclosed in Japanese Patent No. 55674, a cement-kneaded product containing cement, aggregate and water (also called cement mortar) is pressure-molded to form a cement-molded product, and before the cement-molded product is hydrated and hardened. Manufactured by firing at about 800 ° C. and hydrating and hardening the fired product, or as disclosed in Japanese Patent Publication No. 56-48464, a cement kneaded product containing cement, aggregate and water (cement (Also referred to as mortar) is subjected to pressure dehydration molding to form a cement molded product having a water solid content ratio of 0.15 or less, and the cement molded product is preliminarily hydrated and cured at about 800 ° C. It is manufactured by firing and hydration curing the fired product.

Also, in the production of glazed cement products with high mechanical strength, glaze is applied to the surface of the cement molded product treated as described above,
After firing at about 800 ° C. to fuse the glaze to the cement molded product, a step of hydrating and hardening this is performed.

(Problems to be Solved by the Invention) However, in the above-described conventional manufacturing method, the base material strength of the baked product immediately after baking is low, and the bending strength of the base material after hydration curing is, for example, 130 kgf / cm ₂ However, there was still a problem in increasing the size or thinning of cement products. Then, this invention is for solving the above-mentioned conventional problems, and provides a manufacturing method of a cement product which can further improve mechanical strength.

Further, the present invention provides a method for producing a cement product, which is capable of obtaining a cement product having high bending strength and impact strength by incorporating a mesh reinforcement therein.

(Means for Solving Problems) In the study of cement mortar, the present inventor has found that a hydrated cured product obtained by incorporating a mesh reinforcement in a cement kneaded product containing a clay mineral such as talc has a high mechanical strength, especially in bending. It was found that the strength and impact strength were significantly increased. The present invention has been achieved by utilizing the results of this known research.

The first aspect of the present invention relates to a method for producing a cement product, the means of which is that the cement is excellent in plasticity and lubricity, activated during firing and self-sintered, or CaO in the cement.
Clay kneaded material consisting of clay minerals such as talc, which has the property of producing a high-strength substance by reaction and sintering, and other aggregates, and water, is added to the cement kneaded material, and then the mesh kneaded material is added. Pressure dehydration molding is performed to form a cement molded product having a water solid content ratio of 0.20 or less, and the cement molded product is preliminarily hydrated and hardened, and then fired at a temperature of 650 to 900 ° C. to obtain a fired product. None, it is assumed to include a step of fully hydrating and hardening the baked product.

The second invention relates to a method for producing a glazed cement product which is glazed on a predetermined portion of the surface. Is the means of the second invention excellent in cement, plasticity and lubricity and activated during firing to self-sinter? Alternatively, a clay mineral such as talc having a property of reacting with CaO in cement to produce a high-strength substance, another aggregate, and water and a cement kneaded product are subjected to pressure dehydration molding, and the water solid content ratio is After forming a cement molded product of 0.20 or less and preliminarily hydrating and hardening the cement molded product,
A glaze is applied to the predetermined surface to form a glaze-molded product, and the glaze-molded product is baked at a temperature of 650 to 900 ° C. to form a glaze-baked product in which the glaze is fused. And a step of sufficiently hydrating and hardening.

The cement used in the present invention may be any of Portland cement, alumina cement, and mixed Portland cement.

The clay mineral is talc (3MgO.4SiO ₂ .H
₂ O), or kaolinite (kaolin), sericite, etc., which are activated during firing and self-sinter, or a clay-based mineral substance that produces a high-strength substance by reaction sintering with CaO in the cement mixture. The thing of is adopted.

Aggregates that are stable and do not undergo rapid expansion or contraction during the firing process, such as ceramic or porcelain chamotte, river sand,
Silica sand, sea sand, andesite, basalt, hard sandstone, feldspar, anti-firestone, water slag, etc. are used, but ceramic chamotte is particularly effective for strength recovery.

The raw material composition of the cement kneaded product is about 20 to 6 cement.
0 parts by weight, about 15 to 55 parts by weight of clay mineral such as talc, preferably 20 to 50 parts by weight, and about 40 parts by weight or less of other aggregates, preferably 25 parts by weight or less. The cement kneaded product is an admixture for cement, clay mineral, aggregate and water, such as a binder, a sizing material, a water reducing agent, a plasticizer, a fluidizing agent and a dispersant, which are usually added during the production of cement products. Can be appropriately selected and added and kneaded. It is desirable to shorten the time required for this kneading operation and the time for leaving the mixture after kneading until molding, in the sense that hydration hardening is prevented from proceeding before the molding step as much as possible.

The above net-like reinforcement is a metal net such as a stainless net,
Inorganic nets of carbon fiber or glass fiber, nets of synthetic resin, carbon fiber-based, metal fiber-based or glass fiber-based non-woven fabrics are used. The thickness (diameter) of the wire or fiber of the mesh body, the mesh size, or the thickness in the case of a non-woven fabric is appropriately selected as necessary.

The above-mentioned "pressurized dehydration molding" means that a cement kneaded product in a liquid state, a slurry state or a plastic state is cast into a mold at a young age or directly after being strained without being cast into a mold, compressed air, etc. Literally, it is not limited to literally applying positive pressure to dehydrate and mold with a pressure machine such as a water pressure machine, a hydraulic machine or a centrifuge, and to cast a cement kneaded product into a water-absorbing and breathable mold. It is a concept including dewatering and molding by reducing the pressure in the mold after the charging, that is, by applying a negative pressure.

The water solids ratio refers to the weight ratio of water to the total weight of cement and aggregate. The water-solid ratio of the cement kneaded product in the present invention is almost the same as the conventional one, but the water-solid ratio of the pressure dehydration molded product is 0.20 or less. If this value is larger than 0.20, the structure of the pressure dehydration molded product is less densified and the strength of the cement product is lower.

Preliminary hydration hardening (also called initial hydration or initial curing) of the cement molded product causes a part of the mixed cement components to react, resulting in full-scale hydration hardening after firing (also called rehydration). The remaining amount of cement components reacts.

Firing at 650 to 900 ° C has the function of increasing the mechanical strength of the cement product or the glazed cement product.

When a cement kneaded product is molded, a pressure dehydration molding method is adopted, and when pressure is applied to the cement molded product and its content is reduced, as is generally known, a hydration hardening step is performed. The method in which the cement product and the glazed cement product have large strength can be obtained by the method in which it is divided into two and preliminarily performed before the firing step. And, it is better to carry out the preliminary moisture curing step for a longer time than for a short time.

In the case of producing a glazed cement product by the second method of the present invention, it is desirable to perform preliminary firing at 300 to 400 ° C. for about 30 to 60 minutes before or after the step of applying a glaze to the cement molded product. . Since water vapor and carbon dioxide gas are generated when firing the cement hydrate, such preliminary firing is performed in order to remove them in advance. This preliminary firing may be performed separately from the main firing in the preheating section of the main firing furnace, but the preliminary firing and the main firing in the firing section of the main firing furnace do not have a time gap between them, It is also possible to carry out continuously.

In the present invention, an inexpensive frit glaze used for the production of tiles, pottery tiles, novelty, etc. can be used as it is, and by appropriately blending raw materials such as feldspar and clay, the weatherability of the glazed surface can be improved. Resistance, abrasion resistance and chemical resistance can be improved. Furthermore, the desired color and gloss of the glazed surface can be obtained. Other glazes that can be used in the present invention include raw glaze and volatile oil.

The firing time and firing temperature in the firing step can be appropriately determined within the above-mentioned temperature range, but are usually 650 to 900 ° C.
Bake for 5 to 60 minutes.

According to the measurement experiment of the mechanical strength of the cement product obtained by the present invention, the mechanical strength is changed by the firing temperature,
It was found that the strength increases as the firing temperature is raised up to around 800 ° C, but the strength decreases conversely when the temperature exceeds 900 ° C due to progress of sintering and intensification of shrinkage.

(Function) In the present invention, the hardening mechanism of cement and talc for hardening the cement kneaded product is considered as shown in Table 1.

That is, the cement particles are mixed with water, kneaded, molded, and fired in the initial hydration stage before the firing and the C--S--H gel and Ca.
It produces (OH) ₂ and develops strength. This C-S-H gel is dehydrated and decomposed by firing, but rehydrated after firing to become a C-S-H gel again and recover its strength. Cement particles that have not reacted in the initial hydration stage are C--S during rehydration after firing.
-H gel and Ca (OH) ₂ are produced to develop strength. Talc is dehydrated and activated during firing, and CaO existing around
[C-O of low crystallinity] which is reacted and sintered with [CaO generated by decomposition of Ca (OH) ₂ , free CaO present in a trace amount in cement, and CaO generated by decomposition of gypsum added in cement] It becomes an MS compound.

Therefore, in the present invention, the base material strength immediately after firing is high,
In addition, the flexural strength of the base material after hydration curing can be extremely strong.

In the present invention, (a) the cement kneaded product contains clay minerals such as talc and has excellent plasticity and lubricity, so that it firmly adheres to the net-like reinforcement by pressure dehydration molding, and The voids such as fine bubbles are eliminated and the structure is densified, which helps increase the mechanical strength of the cement product.

(B) The components of the unreacted cement particles in the initial hydration step are activated by the firing step and are hydrated and hardened in the hydration step after firing, which functions to increase the mechanical strength of the cement product.

(C) Since the cement kneaded product is subjected to pressure dehydration molding to a water solid content ratio of 0.20 or less, two hydration hardenings performed before and after the firing step function to increase the mechanical strength of the cement product.

(D) Sintering and shrinkage are gentle in firing at 650 to 900 ° C, and the unhydrated portion inside the cement particles is hydrated and hardened to a considerable extent by curing after firing to further enhance the strength of the product. Works like. In addition, "curing" here
May be any means for supplying a sufficient amount of water.

(E) Clay minerals such as talc contained in the cement kneaded product are activated in the firing step and self-sintered, or react and sinter with CaO in the cement kneaded product to form a low crystalline compound such as CMS. Therefore, the strength of the base material immediately after firing is high,
In addition, this substance does not change even after rehydration (hydration hardening) after firing, and thus contributes to increase in mechanical strength of the cement product.

(F) Due to each of the above-mentioned actions, the cement product is integrally hardened in a state where the net-like reinforcing body is present therein, and the physical strength of the net-like reinforcing body is also added to the cement product to have an extremely high strength.

Then, in the second invention, (g) the glaze-molded article is baked at 650 to 900 ° C., so that the glaze is reliably fused.

(4) The other functions are basically the same as those of the first invention.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

FIG. 1 shows a mold 1 for obtaining a cement product 8 of a predetermined shape.
And the inside is the molding part 2. This mold 1 is made of a material that can sufficiently withstand a predetermined pressure applied when molding a cement kneaded product, and at least the entire bottom surface is provided with dehydration holes 3 to 3 composed of fine holes.

The cement kneaded material 4 is supplied to the molding die 1 in a predetermined layer (see the phantom line in FIG. 1).

Next, the reinforcing member 5 is placed on the layer of the cement kneaded material 4 of the molding part 2 (see FIG. 2). Then, the cement kneaded material 4 is supplied in a predetermined layer form on the net-like reinforcement 5 of the molding part 2 (see FIG. 3). Then, the pressure plate 6 is placed on the cement kneaded material 4 of the molding die 1, and the cement kneaded material 4 in the molding part 2 is pressurized and dehydrated by a predetermined pressing force (see FIG. 4).
Then, a molded product 7 having a water solid content ratio of 0.20 or less is formed, and preliminary hydration hardening is performed.

During the pressure dehydration molding, a predetermined amount of water in the cement kneaded material 4 is discharged from the dehydration holes 3 to 3 on the bottom surface of the molding die 1.

Since the cement kneaded product 4 has a good slipperiness due to the addition of talc, the cement kneaded product 4 is made to sufficiently dig into the mesh of the mesh reinforcement 5 in the pressure dehydration molding, and the cement kneaded product 4 and the mesh reinforcement are reinforced. Body 5 is closely attached,
The fine pores in the cement-kneaded product 4 are eliminated, and the molded product 7 has a structure in which the net-like reinforcing body 5 is present and which has a high density.

The molded product 7 is demolded and fired at 650 ° C. to 900 ° C., or is demolded after firing and is subjected to full-scale hydration hardening to obtain a cement product 8 in which the net-like reinforcement 5 is embedded (FIG. 5). reference).

In this example, however, as a cement kneaded material, (A) 40 parts by weight of cement, 40 parts by weight of talc, and 20 parts by weight of other aggregates (mainly porcelain chamotte) are mixed, and a water-cement ratio of 100 to 200 is used. (B) 30 parts by weight of cement, 50 parts by weight of talc, and 20 parts by weight of other aggregate (mainly porcelain chamotte) and a mixture B having a water cement ratio of 100 to 200 were prepared.

As the net-like reinforcing member, four kinds of metal nets having different wire diameters and openings were used.

According to the above-mentioned process, by combining the kneaded products of the combination A and the combination B with four kinds of stainless steel net-like reinforcements, 1
00 kgf / cm ² , pressure dehydration molding for 2 seconds, water solids ratio of 0.14 to 0.16 at this time, after preliminary hydration curing (2
16hr in 0 ° C humid air), calcination temperature of about 850 ° C for 30 minutes, and then full-scale hydration hardening (steam 60 ° C, curing for 3 days) to make a cement product, and test this bending strength and falling ball impact. I did.

The bending strength was measured using a cement product sample of 50 × 100 × 10 mm, and the falling ball impact was 5 × 10 cm and the thickness was 10
The measurement was performed by dropping a 500 g steel ball from above onto a sample of cement product of mm.

The bending strength and falling ball impact test results of the cement product of this example are shown in Tables 2 and 3 below.

As is clear from the results in Tables 2 and 3, the flexural strength in this example is 40 depending on the size of the mesh reinforcement.
About twice the effect was observed with an increase in kgf / cm ² and impact.

(Effects of the Invention) The cement kneaded product in the present invention contains a clay mineral such as talc and has excellent plasticity and lubricity,
The pressure dehydration molding reliably adheres to the net-like reinforcement, and voids such as fine bubbles in the molded product are eliminated, the structure is densified, and the mechanical strength of the cement product is increased.

In addition, the components of the unreacted cement particles in the initial hydration step are activated by the firing step and are hydrated and hardened in the hydration step after firing, which increases the mechanical strength of the cement product.

In addition, since the cement-kneaded product is subjected to pressure dehydration molding to a water solid content ratio of 0.20 or less, the hydration hardening twice performed before and after the firing step increases the mechanical strength of the cement product.

In addition, sintering at 650 to 900 ° C causes mild progress of sintering and shrinkage, and the unhydrated portion inside the cement particles is hydrated and hardened to a considerable extent by curing after the sintering to further enhance the strength of the product. You can

Further, clay minerals such as talc contained in the cement kneaded product are activated in the firing step and self-sintered, or react and sinter with CaO in the cement kneaded product to form a low crystalline compound such as CMS. Because of the change, the substrate strength immediately after firing is high,
Moreover, since this substance does not change even after rehydration (hydration hardening) after firing, the mechanical strength of the cement product is increased.

Due to each of the above actions, the cement product is integrally hardened in the state where the net-like reinforcing member is present therein, and the physical strength of the net-like reinforcing member is also added, so that the cement product has an extremely high strength.

[Brief description of drawings]

1 shows an embodiment of the present invention, FIG. 1 is a cross-sectional view of a mold for filling a cement kneaded product, FIG. 2 is a cross-sectional view of a mold in which a metal net is arranged, FIG. 3 is a cross-sectional view of a molding die in which cement kneaded material is further packed in layers, No. 4
The figure is a process drawing of pressure dehydration molding, and FIG. 5 is a sectional view of a cement product. 1 ... Mold, 4 ... Cement kneaded product 5 ... Reinforcing body, 6 ... Pressure plate 7 ... Molded product, 8 ... Cement product

Claims (14)

[Claims] 1. A cement, a clay mineral such as talc which is excellent in plasticity and lubricity and which is activated upon firing and self-sinters or reacts with CaO in the cement to produce a high-strength substance, and further. After the net-like reinforcing body is incorporated in the cement kneaded product consisting of the aggregate and water, the cement kneaded product is subjected to pressure dehydration molding to form a cement molded product having a water solid content ratio of 0.20 or less, After preliminarily hydrating and hardening the cement molded product, it is baked at a temperature of 650 to 900 ° C. to obtain a baked product,
A method for producing a cement product containing a net-like reinforcement, wherein the calcined product is sufficiently hydrated and hardened. 2. The clay mineral is 3MgO.4SiO ₂ .H ₂
Claim 1 which is talc powder consisting of O component.
A method for producing a cement product containing a net-like reinforcing body according to the item. 3. The other aggregate is at least selected from the group consisting of porcelain chamotte, porcelain chamotte, river sand, silica sand, sea sand, andesite, basalt, hard sandstone, feldspar, anti-fire stone and water slag. The method for producing a cement product containing a net-like reinforcing body according to claim 1, which is a kind. 4. The method for producing a cement product containing a mesh reinforcement according to claim 1, wherein the mesh reinforcement comprises a metal mesh such as a stainless mesh. 5. The method for producing a cement product containing a mesh reinforcement according to claim 1, wherein the mesh reinforcement is made of an inorganic mesh such as carbon fiber or glass fiber. 6. The method for producing a cement product containing a net-like reinforcing member according to claim 1, wherein the net-like reinforcing member is made of a synthetic resin net. 7. The method for producing a cement product containing a mesh reinforcement according to claim 1, wherein the mesh reinforcement is made of a carbon fiber-based, metal fiber-based or glass fiber-based nonwoven fabric. 8. A cement, a clay mineral such as talc, which has excellent plasticity and lubricity and which is activated upon firing and self-sinters or reacts with CaO in the cement to produce a high-strength substance, and further. After the net-like reinforcing body is incorporated in the cement kneaded product consisting of the aggregate and water, the cement kneaded product is subjected to pressure dehydration molding to form a cement molded product having a water solid content ratio of 0.20 or less, After the cement molded product is preliminarily hydrated and hardened, a glaze is applied to a predetermined surface of the cement molded product to obtain a glazed molded product. 6
A method for producing a glazed cement product containing a net-like reinforcing body, which comprises firing at a temperature of 50 to 900 ° C. to obtain a glazed fired product in which a glaze is fused, and the fired product is sufficiently hydrated and hardened. 9. The clay mineral is 3MgO.4SiO ₂ .H ₂
9. A talc powder consisting of O component.
A method for producing a glazed cement product containing a net-like reinforcing body according to the item. 10. The at least another aggregate is selected from the group consisting of earthenware chamotte, porcelain chamotte, river sand, silica sand, sea sand, andesite, basalt, hard sandstone, feldspar, anti-firestone and water slag. Claim 8 which is a kind
A method for producing a glazed cement product containing a net-like reinforcing body according to the item. 11. The method for producing a glazed cement product containing a mesh reinforcement according to claim 8, wherein the mesh reinforcement is made of a metal mesh such as a stainless mesh. 12. The method for producing a glazed cement product containing a net-like reinforcement according to claim 8, wherein the net-like reinforcement is made of an inorganic net such as carbon fiber or glass fiber. 13. The method for producing a glazed cement product containing a mesh reinforcement according to claim 8, wherein the mesh reinforcement is made of a carbon fiber type, metal fiber type or glass fiber type non-woven fabric. 14. The method for producing a glazed cement product containing a net-like reinforcement according to claim 8, wherein the glaze is frit glaze alone, or frit glaze is blended with raw materials such as feldspar.