JPH058149B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a method of manufacturing a cement-based building material that is lightweight, has practical strength, and has excellent heat insulation properties by extrusion molding. BACKGROUND ART Conventionally, as a method for manufacturing cement building materials by extrusion molding, for example, it is known to add sand to cement, use asbestos fiber as a reinforcing material, mix an extrusion aid, and add water. This product is formed into a hollow structure by extrusion and used as an exterior wall material for residential building materials, but its absolute dry specific gravity is as high as 1.7 to 1.9, making it unsuitable as a lightweight building material. On the other hand, in order to reduce weight, lightweight foamed aggregates such as perlite and shirasu balloons have been proposed, but if the amount of these is increased, the shirasu balloons and perlite aggregates will be destroyed by the shear force during extrusion molding. As a result, the composition of the raw materials changes, resulting in poor extrusion moldability and the inability to reduce weight.Therefore, there is a natural limit to the amount that can be blended, and only an absolute dry specific gravity of about 1.5 can be obtained, and satisfactory results have not been obtained. . In addition, it is also known to generate a gel by adding slag and slaked lime to slag and heating it, or by adding silicon dust to cement and heating it, and using this as an ingredient to manufacture lightweight building materials ( (Japanese Patent Publication No. 59-32418, Japanese Patent Publication No. 61-46404), these have an industrial problem in that they require a special heating step for gelation. Problems to be Solved by the Invention The present invention is a lightweight building material that can be prepared by simply kneading without requiring any special processing steps, and that has sufficient mechanical strength to be put to practical use by extrusion molding. The purpose of this work was to provide a method for manufacturing. Means for Solving the Problems The present inventors have worked diligently to develop a method for manufacturing, by extrusion molding, a lightweight building material that has sufficient mechanical strength for practical use and has a low absolute dry specific gravity. As a result of repeated research, we have found that if you use aggregate that has an average particle size of at least 5 times the average particle size of Shirasu balloons and a particle strength greater than that of Shirasu balloons, as part of the aggregate,
Even if the amount of Shirasu balloons is increased, shear failure can be significantly reduced, extrusion moldability will not be impaired, and when used in combination with reinforcing fibers, a cement building material with sufficient mechanical strength can be obtained. Based on this finding, the present invention was completed. That is, the present invention has a basic composition of 100 parts by volume of cement and 100 to 400 parts by volume of shirasu balloons.
10 to 40 parts by weight of aggregate having a particle size equal to or larger than that of the Shirasu balloon and having high particle strength;
1 to 10 parts by weight of reinforcing fibers and 0.5 to 3.0 parts by weight of an extrusion aid are blended, and the water content is 30 to 30 parts by weight based on the total weight.
The present invention provides a method for manufacturing cement building materials by adjusting the content to a range of 50% by weight and extrusion molding. The cement constituting the basic composition of the present invention can be arbitrarily selected from commonly used portland cement, magnesia cement, alumina cement, and mixed cement. Moreover, the shirasu balloon used with cement is not completely spherical, but may be of a partially open type or multiple fused type. These are manufactured by crushing and firing shirasu, an acidic volcanic ejecta widely distributed in southern Kyushu. In the present invention, the foam thus obtained has an average particle diameter of 20 to 150 μm, preferably 30 to 80 μm. It is necessary to use this product in a proportion of 100 to 400 parts by volume per 100 parts by volume of cement. If the amount is less than this, the absolute dry specific gravity cannot be made sufficiently low, and the weight reduction will be incomplete.
On the other hand, if the amount is larger than this, the formability cannot be improved even if aggregate is used in combination, and an extruded building material with practical strength cannot be obtained. Next, in the present invention, river sand, mountain sand, crushed sand, silica sand, or crystalline limestone, slagstone, basalt, etc. may be added to the basic composition of cement and shirasu balloon as part of the aggregate. is necessary. As these aggregates, commonly used aggregates are used as long as they have a particle strength equal to or higher than that of Shirasu balloons, and they are ground into particles with an average particle diameter of at least 5 times that of Shirasu balloons, and the basic composition is 100%.
It is blended in a range of 10 to 40 parts by weight. If the blending amount is less than or greater than the above range, the mechanical strength will be reduced and the moldability will be poor, making it impossible to achieve the object of the present invention. Next, as reinforcing fibers, inorganic fibers such as glass fibers, asbestos, and carbon fibers, and organic fibers such as pulp, vinylon fibers, polypropylene fibers, and aramid fibers can be used, but particularly preferred are asbestos and alkali-resistant glass. It is a fiber. These may be used alone or in combination of two or more. These reinforcing fibers are used in an amount of 1 to 10 parts by weight per 100 parts by weight of the basic composition. If the amount is less than this, a sufficient reinforcing effect cannot be obtained, and if the amount is larger than this, the reinforcing effect does not increase, but rather causes a decrease in other physical properties and extrusion moldability, which is not preferable. . Furthermore, in the production method of the present invention, it is necessary to add an extrusion aid to facilitate extrusion molding, and the extrusion aid is preferably a cellulose derivative such as methylcellulose, ethylcellulose, or carboxymethylcellulose. Other materials such as polyvinyl alcohol can also be used. These molding aids are blended in a proportion of 0.5 to 3.0 parts by weight per 100 parts by weight of the basic composition. If the amount is less than this, sufficient moldability cannot be obtained, and even if the amount is increased more than this, no further improvement in moldability can be expected. The present invention has the above-mentioned components as essential components, but in addition, additives conventionally used in cement systems for extrusion molding, such as perlite, silica flour, vermiculite, etc., may be added as desired. It can also be blended in an amount that does not impair the physical properties and extrusion moldability. Furthermore, in the present invention, it is necessary to keep the water content in the range of 30 to 50% by weight based on the total solid weight. If this amount is less than 30% by weight, the material will become clogged in the die during extrusion molding, and smooth extrusion will not be possible.If this amount exceeds 50% by weight, it will be too soft and will lose its shape retention. It becomes impossible. To prepare the extruded material of the present invention, cement,
Shirasu balloons, aggregates, fibers, extrusion aids, and water are blended in predetermined proportions and kneaded using a suitable kneader.
The material thus obtained is extruded according to a conventional method, and cured in water, in air, and at ^high temperature and pressure.
It is possible to produce lightweight insulating building materials of 1.4 or higher. Effects of the Invention The production method of the present invention can be produced simply by blending prepared aggregates without special treatment such as gelation reaction, and moreover, by ordinary extrusion molding, Has practical strength,
Since it provides a lightweight building material with a low absolute dry specific gravity of 1.4 or less, it is suitable as an extrusion manufacturing method for lightweight cement building materials. Examples Next, the present invention will be explained in more detail with reference to Examples. In addition, the physical property values in each example were measured by the following method. (i) Bending strength: A molded product made by extrusion molding a predetermined composition is allowed to stand in a wet state for one day, and then cured in water at 20°C for 14 days to harden it.
The measurement was carried out using Autograph AG-5000A manufactured by Shimadzu Corporation, with centrally concentrated loading at a span of 100 mm and a loading speed of 2 mm/min. (ii) Specific gravity; After drying the cured product obtained by extrusion molding and curing a predetermined composition at 105° C. for 24 hours, the weight and dimensions were measured, and the bulk specific gravity was calculated based on these. (iii) Moldability: The prescribed composition was extruded using a DE-100 extrusion molding machine manufactured by Honda Iron Works Co., Ltd. to form a cross section of 20 x 200.
A hollow flat plate of mm was manufactured, and the molding state at that time was visually observed and evaluated according to the following criteria. ×...It was blocked and could not be molded. △...Canine-shaped cracks, cracks, blisters, etc. were produced. ○...Good moldability was shown. Example 1 100 parts by volume of Portland cement [manufactured by Ube Industries, Ltd.] and 400 parts by volume of Shirasu Balloon [trade name: "Winlight" MSB-3011, manufactured by Ijichi Kasei Co., Ltd.] were mixed, and per 100 parts by weight of this mixture. , extrusion aid [“Methylcellulose” 90SH-15000 manufactured by Shin-Etsu Chemical Co., Ltd.]
2 parts by weight, 4 parts by weight of alkali-resistant shirasu glass fibers, and 30 parts by weight of crystalline limestone aggregate, and further water was added to adjust the moisture content to 40% by weight to prepare a cement composition. This material was extruded using a Honda Ironworks DE-100 type extrusion molding machine, with a cross section of 20 x 200 mm.
A plate-like body was manufactured. The molded product thus obtained had a bulk specific gravity of 1.03 and a bending strength of 72 Kg/cm ² . Example 2 100 parts by weight of a mixture of 100 parts by volume of the same cement used in Example 1 and 300 parts by volume of Shirasu balloons [Winlite SB-9011 manufactured by Ijichi Kasei Co., Ltd.], 1.5 parts by weight of methyl cellulose, and alkali resistance Add 2 parts by weight of shirasu glass fiber and 5 parts by weight of asbestos,
Furthermore, different amounts of crystalline limestone aggregate were added to prepare compositions with a moisture content of 30% by weight. This material was extrusion molded in the same manner as in Example 1, and the physical properties of the molded product obtained are shown in the following table.

[Table] Example 3 30 parts by weight of silica sand No. 6 aggregate was used instead of the limestone aggregate in Example 1, and vinylon fiber [RFS-602 manufactured by Kuraray Co., Ltd.] 1 was used instead of the alkali-resistant glass fiber.
A cement composition for extrusion molding was prepared in exactly the same manner as in Example 1 except that parts by weight were used. A molded article obtained by extrusion molding this composition in the same manner as in Example 1 had a bulk specific gravity of 1.1 and a bending strength of 90 kg/cm ² .

Claims (1)

[Claims] 1 100 volume parts of cement and 100 ~ Shirasu balloons
For 100 parts by weight of the basic composition consisting of 400 parts by volume,
10 to 40 parts by weight of aggregate with an average particle diameter equal to or more than 5 times the average particle diameter of Shirasu balloons and a particle strength greater than that of Shirasu balloons, and 1.0 parts of reinforcing fibers.
A method for producing a lightweight cement product, which comprises blending ~10 parts by weight and 0.5 to 3.0 parts by weight of an extrusion aid, adjusting the water content to a range of 30 to 50% by weight based on the total weight, and extrusion molding.