JPS5825059B2 - Manufacturing method of inorganic cured body - Google Patents

Description

[Detailed description of the invention] This invention relates to a method for producing an inorganic cured product.

Conventionally, calcium aluminate trisulfate hydrate (3CaO・Al2O3・3CaSO3・nH2
An inorganic hardened body mainly composed of hardened blast furnace slag (O+n takes a value of approximately 31 or 32 (hereinafter abbreviated as TSH)) was manufactured as follows.

That is, calcium aluminate monosulfate hydrate (3CaO・Al10
3 ・Create a slurry by kneading CaSO4HnH20 (n takes a value of approximately 12, hereinafter abbreviated as MSH), gypsum, blast furnace slag, and water, and shape this into a predetermined shape by papermaking, pouring, etc. Then, this excipient was left indoors and cured at room temperature for one day, then moist heat cured at 60°C for 24 hours, and then cured again at room temperature to react with MSH and gypsum to form TSH. It was produced by water-hardening blast furnace slag.

The inorganic cured body produced in this way has a fairly dense structure and relatively high strength.

However, it is expected that an inorganic cured product with a denser structure and higher strength will be realized.

The present invention was made in view of the above circumstances, and involves shaping a slurry for an inorganic hardened body containing a calcium aluminate trisulfate hydrate precursor composition and blast furnace slag into a predetermined shape, and forming this shaped body into a predetermined shape. This is a method of manufacturing an inorganic cured body by curing and curing, in which the shaped body is placed in a moist heat atmosphere for a long time after being shaped and cured for a predetermined period of time, resulting in a more dense structure and higher quality. This method produces a strong inorganic cured product.

Next, this invention will be explained in detail.

The TSH production reaction during the production of inorganic hardened bodies proceeds much faster than the water utilization reaction of blast furnace slag, even if the excipients are left indoors and cured at room temperature. The process progresses fastest when cured in an atmosphere that can be heated while suppressing moisture evaporation.

On the other hand, the hydration reaction of blast furnace slag is extremely slow at room temperature.
Moist heat curing of the excipient at 80 to 90° C. (curing performed in a moist heat atmosphere) will significantly speed up the process.

Therefore, when curing the excipient, if the excipient is left indoors at room temperature for a long time, the TSH production reaction will proceed first, and at that time, the TSH production reaction will proceed.
Due to the expansion of the excipient due to the production of H and the development of needle-like crystals of the generated TSH, large voids are created in the excipient, and then, after the voids are created in the excipient, the blast furnace slag is hardened by water use.

Therefore, the resulting inorganic cured product is unlikely to have a dense structure.

When the excipient was placed indoors at room temperature, the TSH
The production reaction begins to proceed after a short period of time, for example, 4 to 8 hours after imprinting.

Therefore, if the excipient is placed in a moist heat atmosphere and heated while suppressing moisture evaporation to simultaneously perform TSH formation and curing of the blast furnace slag, the expansion of the excipient will be suppressed and it will become denser. A high-strength inorganic cured product with a unique structure can be obtained.

Note that when heating and curing the excipient, it is necessary to do so in such a way that the water in the excipient does not evaporate.

If water evaporates, the TSH production reaction and the blast furnace slag water utilization reaction will be inhibited.

As mentioned above, when the shaped body is cured in a moist heat atmosphere, it is preferable to leave the shaped body in a moist heat atmosphere at a temperature of 80 to 90° C. and humidity saturation.

When the temperature drops below 80°C, the reaction rate of the TSH production reaction becomes faster than the hardening rate of blast furnace slag.
As the excipient begins to expand, the development of TSH needle-like crystals progresses too much.

On the other hand, if the temperature exceeds 90° C., the TSH generation reaction becomes extremely slow, so that TSH formation occurs after moist heat curing, which tends to cause cracks in the cured product.

The moist heat curing time is preferably 6 to 24 hours, more preferably 12 to 24 hours.

If the curing time is less than 6 hours, sufficient reaction occurs during that time.

Since this is not carried out, the resulting cured product becomes soft, making it inconvenient to transport.Moreover, the reaction continues even after curing, which tends to cause expansion of the cured product.

Conversely, even if the curing time exceeds 24 hours, no further increase in effect occurs.

4 Then, the obtained inorganic cured product is cured with moist heat, for example, indoors at room temperature, and then manufactured into a product.

Of the raw materials used in this invention, the TSH precursor composition refers to TSH precursor composition that reacts with at least one of a gypsum component, a lime component, and an alumina component in the presence of water.
A composition containing a TSH precursor and at least one of the above components.

Such compositions include, for example, C3A (3CaO-
A1203), C5AH6 (3CaO-A1203/6
H20) 1゜C4A4S (3CaOe 3A t 2
031 CaSO4).

Al1 (SO4)? TSH precursors such as I ・nH2O2M5H and gypsum components such as gypsum and CaO
Examples include those containing at least one lime component such as.

Further, as the blast furnace slag, a normal one having hydraulic properties is used.

Further, raw materials other than those mentioned above, such as reinforcing materials, may be used freely.

In this invention, a TSH precursor composition, that is, a composition for a cured body material that can produce a cured body containing TSH as a main component upon curing, is contained in an uncured state in the inorganic cured body material. This is very important.

As a result, the water-use hardening of this composition and the water-use hardening of the blast furnace slag occur simultaneously, so that the TSH obtained by the water-use hardening of this composition and the hydrated blast furnace slag are uniformly and firmly bonded. This is because an entangled state appears, and the resulting inorganic hardened product has even higher strength than an inorganic hardened product made of hydrated blast furnace slag alone.

On the other hand, when the TSH is blended in advance, such an effect cannot be expected at all.

The attached drawings clearly illustrate this.

In other words, the ○ line and the - line indicate (blast furnace slag/
The relationship between TSH) ratio and bending strength is shown, and the Δ line and A line show the same relationship as above when blended in the TSH state, but if you look at the slope of each line, you can see that I understand that very well.

Such characteristics of the inorganic cured material obtained by the method according to the present invention are particularly effective when this material is used for manufacturing exterior building materials and the like.

This is because exterior building materials and the like are required to be lightweight and have high strength.

As described above, in the present invention, after shaping a slurry for an inorganic hardened body containing a TSH precursor composition and blast furnace slag,
Since the molded body is cured in a moist heat atmosphere for a short period of time, it is possible to produce an inorganic cured body with a dense structure and high strength.

Next, examples will be described together with comparative examples.

That is, MSH, gypsum, and blast furnace slag are blended in the produced inorganic hardened product so that the weight ratio of TSH and blast furnace slag hardened product is 1:1, and alkali-resistant glass fiber and pulp are added to the produced inorganic hardened product. 0.5% by weight of alkali-resistant glass fiber and 0.6% by weight of pulp in the cured product
These are mixed with water to make a slurry, shaped, and the shaped body is cured under the conditions shown in Table 1 (the curing time is one week in total). An inorganic cured body having a bulk specific gravity of 1.00 was produced.

The performance of the inorganic cured product is shown in Table 2.

In addition, in Tables 1 and 2, Flats 1 to 3 are comparative examples.

The shaped bodies were cured under the conditions shown in Table 1 immediately after shaping.

As is clear from Table 2, the inorganic cured product of Example (44
-12) have higher normal strength than the comparative examples (/I61-3), and most of them show less decrease in strength upon water absorption than the comparative examples.

[Brief explanation of the drawing]

The drawings are explanatory diagrams for explaining the invention in detail.

Claims (1)

[Claims] 1. A slurry for an inorganic hardened body containing a calcium aluminate trisulfate hydrate precursor composition and blast furnace slag is shaped into a predetermined shape, and the shaped body is cured and hardened to form an inorganic hardened body. 1. A method for producing a cured inorganic body, the method comprising: placing the shaped body in a moist heat atmosphere for a long time after shaping and curing it for a predetermined period of time. 2. The difficult time after imposition is a period of 4 to 8 hours after imposition, the moist heat atmosphere is a moist heat atmosphere with a temperature of 80 to 90°C, and the predetermined time is 6 to 24 hours. A method for producing an inorganic cured body according to claim 1.