JPS5915107B2 - Manufacturing method of inorganic cured body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an inorganic cured body used as a building material, particularly a noncombustible building material.

BACKGROUND ART Inorganic cured bodies used as building materials and the like have been manufactured in the following manner.

That is, calcium aluminate monosulfate hydrate (3CaOHA1203, Ca5O4Hn
H20・n has a value of approximately 12, hereinafter referred to as l'
-MSHJ), gypsum, blast furnace slag, cement, and water are formed into a predetermined shape, and the slurry is cured to react with MSH and gypsum with water to produce calcium aluminate trisulfate hydrate. (
3CaO'Al2O3-3CaSO4'nH20tn takes a value of approximately 3 or 32, hereinafter referred to as rTs
It was produced by hardening blast furnace slag and cement using water.

The inorganic cured body produced in this manner has high impact strength and bending strength, and is excellent as a building material.

However, this inorganic cured body shrinks and cracks when heated to high temperatures, which poses a problem as a nonflammable building material.

Therefore, in order to solve this problem, it has been considered to add asbestos to a slurry whose main components are MSH, gypsum, blast furnace slag, cement, and water.

However, asbestos is a specified chemical substance, and its use worsens the working environment and increases costs, so adding asbestos also poses problems.

In view of these circumstances, as a result of repeated research, the inventors added calcium silicate to a slurry whose main components are MSH, gypsum, blast furnace slag, cement, and water, and used this to inorganically harden the slurry. The present invention was completed based on the discovery that when the body is manufactured, an inorganic cured body that does not crack even when heated to high temperatures and has excellent impact resistance and bending strength can be obtained.

That is, this invention can be applied to MSH, gypsum, blast furnace slag,
The gist of this method is to add calcium silicate to a slurry whose main components are cement and water, shape the slurry containing calcium silicate, and then cure and harden the slurry.

Next, this invention will be explained in detail.

In this invention, a slurry whose main components are MSH, gypsum, blast furnace slag, cement, and water is used.

Such a slurry can be prepared by a conventional method, that is, by mixing the above-mentioned raw materials for the slurry and, if necessary, adding additives such as pulp, reinforcing fibers such as glass fibers, and water reducing agents. Manufactured by.

In this case, the state of the slurry does not matter. Therefore, it may be in a highly fluid state or in a pasty state.

Furthermore, the expression "mainly composed of MSH1 gypsum, blast furnace slag, cement, and water" also includes the case where the entire composition is composed only of the main components.

Furthermore, among the raw materials for slurry, cement includes not only Portland cement but all types of cement.

Furthermore, instead of using blast furnace slag and cement separately, blast furnace cement may be used instead.

The present invention allows such a slurry to contain calcium silicate (eg, tobermorite, xonotlite).

This calcium silicate can be incorporated into the slurry by adding and mixing it with the slurry, or by pre-blending it into the slurry raw materials when mixing the slurry raw materials to form a slurry. This is done by placing the

In this case, the content of calcium silicate is determined by the matrix formed by water-hardening MSH, gypsum, blast furnace slag, and cement (hydraulic binder, water-hardened product, and additives such as reinforcing fibers are not included). The maximum number of 5 times (hereinafter 1)
%) or higher.

More preferably, it is 10% or more.

That is, if the content of calcium silicate is out of the above range, the effect will be reduced.

In addition, when the hydraulic binder is water-cured and becomes a matrix, the weight increases by approximately 20 times, so the amount of calcium silicate used is adjusted in consideration of this at the time of blending the raw materials. The content can be adjusted so that it falls within the above range.

In addition, the ratio of MSH and gypsum in the slurry is preferably selected so that the weight ratio of MSH/gypsum is 170.2 to 170.7, and the total content of blast furnace slag + cement is or 2-70% in the matrix
It is preferable to choose such that it occupies .

Moreover, it is preferable to select the matrix so that it occupies 65% or more of the inorganic cured product.

That is, the effect is greatest within these ranges.

Next, the slurry containing calcium silicate is shaped into a predetermined shape by a normal shaping method, that is, by a papermaking method, a casting method, etc., and then subjected to, for example, moist heat curing (high temperature,
After curing under high humidity), it is cured at room temperature for about one week to become a hardened inorganic product.

Due to the action of calcium silicate, the inorganic cured product thus obtained does not crack due to shrinkage even when heated to high temperatures, and has excellent impact resistance and bending strength.

That is, this inorganic cured product does not crack even when heated to high temperatures, so it is particularly useful as a noncombustible building material.

At the same time, examples will be explained together with comparative examples.

[Examples 1 to 5] MSH 35 parts by weight (hereinafter abbreviated as "parts"), dihydrate gypsum 2
0 parts, blast furnace cement 25 parts, pulp 5 parts, glass fiber 2 parts
A slurry is made by adding water and mixing.

Next, calcium silicate was added to this slurry in an amount shown in the table below and mixed, and this was formed into a green sheet (plate-shaped excipient).

Next, this green sheet was pressed to adjust its thickness and specific gravity appropriately.

Then, the pressed green sheet was placed in a heat and humidity curing chamber and was aged at a temperature of 70° C. and a humidity of 100%.

Next, put this in a polyethylene bag and leave it at room temperature.
I left it for a week to cure.

Then, the cured product was dried at 45° C. to a constant weight to obtain an inorganic cured board with a specific gravity of 1.0 and a thickness of 5.5 mm.

[Comparative example]

Addition of calcium silicate was discontinued.

Other than that, inorganic cured plates of the same dimensions were obtained in the same manner as in Examples 1 to 5.

Performance tests were conducted on the inorganic cured plates obtained in the above Examples and Comparative Examples.

The results are also shown in the table below.

As is clear from the table, all of the inorganic cured plates obtained in Examples have good flammability evaluation scores and are excellent as nonflammable materials, and are also excellent in bending strength and Charpy impact strength.

The tests in the table were conducted as follows.

I) Combustibility Test In the combustibility surface test based on JISAI 321, the size of cracks that occurred on the cured board after the test was visually evaluated on a five-level scale and an evaluation score was given.

The smaller and better the crank, the higher the score.

11) Bending test Bending strength was measured using a No. 4 test piece based on JISAI 408.

iii) Charpy impact test A Charpy impact test was conducted according to JIS K6911.

Claims (1)

[Claims] 1. A slurry containing calcium aluminate monosulfate hydrate, gypsum, blast furnace slag, cement, and water as main components and also containing calcium silicate is prepared, and after shaping this slurry, curing, A method for producing an inorganic cured product characterized by curing. 2. The content of calcium silicate is selected to be 5 times or more in a matrix formed by water-curing calcium aluminate monosulfate hydrate, gypsum, blast furnace slag, and cement. A method for producing an inorganic cured product according to item 1.