JPH04130038A - Production of inorganic extruded building material - Google Patents

Abstract

PURPOSE:To obtain the building material having the strength and freezing hazard resistance equiv. to the strength and freezing hazard resistance of asbestos, pulp, etc., by using foamed pearlite in place of pulp at the time of extrusion molding of a slurry prepd. by compounding cement, silica sand, clay, and pulp and uniformly mixing an extrusion assistant and water therewith. CONSTITUTION:The foamed pearlite is added in place of pulp fibers to the cement compd. for extrusion-molding consisting of, for example, by weight %, 48 parts cement, 43 parts silica sand, 10 parts clay, 5 parts pulp fiber, and further, 1 part extrusion-molding assistant (methyl cellulose) and 30 parts water. The foamed pearlite is formed by grinding pearlite and rapidly expanding the ground pearlite under heating. The above-mentioned compd. is made into a slurry and the slurry is extrusion-molded to obtain the building material. The inorg. building material having the excellent freezing hazard resistance is extrusion-molding by this method even if fibers of asbestos, pulp, etc., are not used. Although this building material is slightly inferior to the building materials of the conventional method in terms of strength, moisture content, water absorptivity, sp. gr., etc., this material is within the range sufficiently withstandable as the building material.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing an inorganic extruded building material, which is asbestos-free,
This invention relates to a method for manufacturing an inorganic extruded building material containing no pulp.

[Conventional technology]

Conventionally, building materials have been widely manufactured using mixtures containing cement as the main component, and as a means of manufacturing large quantities of building materials with complex cross-sectional shapes, there has been a manufacturing method in which the above-mentioned cement mixture is made into a slurry and extrusion molded. It is widely practiced.

By the way, asbestos has traditionally been used as a reinforcing fiber to impart shape retention to the uncured molded product in the extrusion molding process, and to impart strength and frost resistance to the cured product.
Since asbestos causes pollution, there is a strong demand for its use to be restricted or completely abolished, and various asbestos alternative fibers are being developed.

Pulp fiber is seen as a promising substitute for asbestos because of its heat resistance, excellent chemical resistance, and its ability to impart frost damage resistance to cement products.

[Problems with conventional technology]

However, the current situation is that restrictions on the use of pulp fibers are gradually being imposed from the viewpoint of nature conservation, and there is a need to further develop reinforcing bodies to replace pulp fibers.

[Problems solved by the invention]

In view of the above-mentioned problems, the present invention provides a method for producing an inorganic building material that does not use reinforcing fibers such as asbestos or pulp at all, and has strength and frost damage resistance, especially frost damage resistance, comparable to those using these fibers. It was done for the purpose of

[Technology to solve problems]

That is, the method for producing inorganic extruded building materials of the present invention involves blending cement, silica sand, clay, and pulp as reinforcing fibers, uniformly mixing with a required amount of extrusion aid and water to form a slurry, and extruding the slurry. A method for manufacturing an inorganic extruded building material that is shaped into a product shape is characterized in that expanded perlite is used in place of the above-mentioned pulp fibers.

[Effect]

This invention is based on extrusion molding, and the blending amounts of cement, warping force, etc. are the same as in the conventional method, and the manufacturing equipment used is also the same as in the conventional method, so there is no particular point to note.

However, in this invention, in place of asbestos or pulp, which has been conventionally used as reinforcing fibers, foamed perlite is used in an amount approximately equal to the amount added.

This foamed pearlite is made by crushing pearlite and rapidly heating and expanding it.

This foamed pearlite has a porous surface and good water absorption, so it has good affinity with the cement matrix.
By uniformly mixing them, almost the same reinforcing effect can be achieved without adding reinforcing fibers.

〔Example〕

Next, the present invention will be explained in detail.

Cement for extrusion molding using a conventional method, comprising 48 parts by weight of cement, 42 parts by weight of silica sand, 10 parts by weight of clay, 5 parts by weight of pulp fiber, and 1 part by weight of methyl cellulose (MC) and 30 parts by weight of water as extrusion aids. In the formulation, the foamed pearlite added in place of the above pulp fibers is foamed pearlite obtained by crushing nacre and rapidly heating and expanding it, having the composition shown in Table 1 and having a unit volume of particle size distribution shown in Table 2. A slurry having a weight of 0.055 kg/n was prepared, and a slurry was prepared using the formulation shown in Table 3.

Table (numbers in the table are parts by weight) Next, among the above blended raw materials, the powder raw materials excluding MC1 water were uniformly mixed in a dry mixer, then uniformly mixed with MC and water in a kneader, and then mixed in a clay extruder. Thickness 1゜2cm, length 30cm
A large number of test pieces with a width of 20cm and a width of 8.5atm
Autoclave curing was performed for 10 hours.

The obtained products were subjected to a bending strength test based on JIS No. 4, and the water content, water absorption rate, air-dried specific gravity, and bone-dry specific gravity were measured. Ta.

Next, a freeze-thaw test was conducted under the following conditions, and the result was 1 in Table 5.
The result was 2 in Table 5.

Freeze-thaw test: Maintain 20°C for 2 hours, cool from 20°C to 20°C over 2 hours, then maintain temperature at -20°C for 2 hours, then raise the temperature to 20°C over 2 hours for one cycle. And so.

Note that in Table 5-1 and Table 5-2, the evaluations are ○: No abnormality in appearance, △: Some abnormalities present, ×: Abnormalities present.

As is clear from Table 4, 1 and 2, and Table 5, 1 and 2, the bending strength is comparable to that obtained using pulp, and the water content, water absorption, air-dry specific gravity, and bone-dry specific gravity are Although it was found to be equivalent to or slightly inferior to the conventional blend in terms of points, it was found in freeze-thaw tests that it exhibited strength incomparable to the conventional blend using pulp fibers.

[Effect] As explained above, according to the method of the present invention, asbestos,
Inorganic building materials with excellent frost damage resistance can be extruded without using fibers such as pulp.

In addition, in terms of strength, water content, water absorption rate, specific gravity, etc., there are some points that are inferior to conventionally formulated products, but they are within the range that can be used as building materials, and conventionally formulated products using pulp fibers. This makes it possible to extrude a building material with excellent strength that is almost comparable to that of other materials.

Claims (1)

[Claims] (1) An inorganic extruded building material in which cement, silica sand, clay, and pulp as reinforcing fibers are mixed uniformly with the required amount of extrusion aid and water to form a slurry, and the slurry is extruded and shaped into a product shape. A method for producing an inorganic extruded building material, characterized in that the method uses expanded perlite in place of the above-mentioned pulp fibers.