Cement for rock wool composition and rock wool composition

Abstract

To provide a cement for a rock wool composition in which a surface of the rock wool composition after hardening is less likely to become mottled even without using expensive white Portland cement, and to provide the rock wool composition in which the surface of the rock wool composition after hardening is less likely to become mottled even without using the expensive white Portland cement.MEANS: A cement having a specific iron content is used, the cement having as main components: cement clinker powder mainly composed of calcium silicate; and a blending material.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a cement for a rock wool composition. In particular, the present invention relates to a cement for a rock wool composition that is less likely to cause color unevenness on the surface when made into a rock wool composition. The present invention also relates to a rock wool composition. In particular, the present invention relates to a rock wool composition that is less likely to cause color unevenness on the surface. [Background technology]

[0002] A fiber layer such as rock wool is provided on the base of a structure surface or the like for the purpose of imparting fire resistance, fire prevention, sound absorption, and / or heat insulation, etc. The fiber layer is generally formed by a spraying method using granular fibers (fiber masses with a diameter of several mm to several cm) and a binder slurry whose main components are water and an inorganic binder such as cement or alkali silicate, or an organic binder made of a polymer such as vinyl acetate resin, acrylic resin, or synthetic rubber. This spraying method, known as a semi-dry method, uses granular rock wool and cement slurry (a binder slurry consisting of cement and water) in a spraying device such as the one shown in Figure 1. The granular rock wool is fed into a device called a rock wool sprayer or deflocculator, where it is pulverized (into fine granules (fiber clumps with diameters of several millimeters to several centimeters)) by a built-in deflocculator such as a rotary cutter. It is then quantitatively pumped into a pressure path by a metering device such as a rotary feeder, and then pressure-fed through a hose by a blower and supplied to a spray nozzle. The cement is mixed with water in a mixer to form a cement slurry, which is then pumped through a conveying pipe (a hose for pumping cement slurry) by a slurry pump to a liquid material (cement slurry) spray nozzle located on the granular fiber spray nozzle. The cement slurry is sprayed from a liquid material (cement slurry) spray nozzle located on the periphery of the granular fiber spray nozzle, or from a liquid material (cement slurry) spray nozzle located near the central axis of the granular fiber spray nozzle, and merges and mixes with the rock wool to form a fiber layer consisting of rock wool and cement hydrate (solidified cement slurry) (see, for example, Patent Documents 1 and 2). Rock wool granular fibers are white or very close to white, while cement slurry is generally gray because ordinary Portland cement is used as the cement, and remains gray even after hardening (solidification). Therefore, the formed fiber layer (rock wool composition) may have white and gray spots (for example, see Non-Patent Document 1 (7. Bulk specific gravity test (photo))). When white Portland cement is used as the cement for the cement slurry, the color after hardening becomes a white color similar to or very close to that of rock wool, and the formed fiber layer (rock wool composition) is not visually recognizable as mottled. However, white Portland cement is considerably more expensive than ordinary Portland cement, making it uneconomical.

[0003] In addition, to prevent the surface of the fiber layer from becoming uneven or to increase its strength, a cement slurry layer (a layer consisting of solidified cement slurry) may be formed by spraying only cement slurry onto the surface of a fiber layer consisting of granular rock wool fibers and cement slurry. In this case, the surface of the cement slurry layer covering the surface of the fiber layer does not have exposed rock wool, so the color of the hardened cement slurry does not become uneven. However, to confirm the quality of the formed fiber layer, a cylindrical sample with a diameter of 80 mm is sampled for quality testing, typically a bone-dry bulk density test, and the sampled hole is filled with rock wool or a separately prepared rock wool composition. The surface of the filled area becomes a different color from the surrounding surface; when the rock wool composition is filled, the color of the rock wool and the color of the cement hydrate are mixed, while when rock wool is filled, the color of the rock wool is used. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-070546 [Patent Document 2] Japanese Patent Publication No. 2020-159093 [Non-patent literature]

[0005] [Non-Patent Document 1] "What should you pay attention to before applying sprayed rock wool? Construction procedures, setup, and inspection methods" [online], The Construction, [May 2024] 31 days search], Internet <URL: https: / / llcreativell.com / 2021 / 11 / 18 / %E3%80%90%E8%80%90%E7%81%AB%E8%A2%AB%E8%A6%86%E3%80%91%E5%90%B9%E4%BB%98 %E3%83%AD%E3%83%83%E3%82%AF%E3%82%A6%E3%83%BC%E3%83%AB%E3%81%AE% E6%96%BD%E5%B7%A5%E5%89%8D%E3%81%AB%E6%B3%A8%E6%84%8F%E3%81%99 / 〉 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a technique that makes it difficult for the surface of a hardened rock wool composition to become mottled, even without using expensive white Portland cement. More specifically, an object of the present invention is to provide a cement for a rock wool composition that makes it difficult for the surface of a hardened rock wool composition to become mottled, even without using expensive white Portland cement. Another object of the present invention is to provide a rock wool composition that is less likely to develop mottle on its surface after hardening, even without using expensive white Portland cement. [Means for solving the problem]

[0007] As a result of extensive research into solving the above problems, the present inventors have found that the above problems can be solved by using cement that is mainly composed of cement clinker powder containing calcium silicate as a main component and an admixture, and that has a specific iron content, and have thus completed the present invention. That is, the present invention is a cement for rock wool compositions represented by the following (1) or (2), and a rock wool composition represented by the following (3) or (4). (1) A cement for rock wool composition, characterized in that the main components are cement clinker powder whose main component is calcium silicate and an admixture, and the iron content is 2.4 mass% or less in terms of Fe2O3. (2) The cement for rock wool compositions according to (1), wherein the content of the cement clinker powder is 1 to 90% by mass and the content of the mineral admixture is 99 to 10% by mass. (3) A rock wool composition characterized by containing rock wool, the cement for rock wool compositions of (1) or (2) above, and water as main components. (4) The rock wool composition of (3) above, in which the rock wool content is 20 to 95 parts by mass, the cement for rock wool composition of (1) or (2) above is 80 to 5 parts by mass, and the water content is 40 to 150 parts by mass, relative to a total of 100 parts by mass of rock wool and cement for rock wool composition. [Effects of the Invention]

[0008] According to the present invention, a cement for a rock wool composition can be obtained that does not require the use of expensive white Portland cement, and that does not cause unevenness on the surface of the rock wool composition (fiber layer) after hardening. According to the present invention, a rock wool composition can be obtained that does not require the use of expensive white Portland cement, and that does not cause unevenness on the surface of the rock wool composition (fiber layer) after hardening. Because the surface of the rock wool composition (fiber layer) does not tend to become uneven, there is no need to spray only cement slurry to form a cement slurry layer in order to prevent unevenness on the surface of the rock wool composition layer, and the step of forming a sprayed cement slurry layer can be omitted. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of an example of a spraying device used in the present invention. [Figure 2] FIG. 2 is a photograph of the specimens of Test Nos. 1 to 8 in the example at 14 days of age. DETAILED DESCRIPTION OF THE INVENTION

[0010] The cement for rock wool compositions of the present invention is characterized in that it is mainly composed of cement clinker powder containing calcium silicate as the main component and an admixture, and has an iron content of 2.4 mass% or less in terms of Fe2O3.

[0011] The rock wool in the present invention refers to a material (mineral fiber) formed by rapidly cooling a material primarily composed of rock or blast furnace slag melted in a melting furnace. For example, it also includes slag wool produced from a material primarily composed of blast furnace slag. The rock wool used in the present invention is preferably agglomerated (granular, fiber agglomerates with a diameter of several mm to several cm) like the granular rock wool used in rock wool-based fire-resistant coating materials, because the resulting rock wool composition layer has low thermal conductivity and is excellent at retaining the shape of the resulting substrate layer. The rock wool aggregate is preferably a granular cotton obtained by subjecting raw cotton consisting of fiberized mineral fibers to one or a combination of two or more processes, such as crushing, deflocculating, cutting, sorting (e.g., sieving), and granulation. Examples of the rock wool granular cotton include fine and micro-sized rock wool granules, and commercially available rock wool granules, fine and micro-sized rock wool granules, such as "S-Fiber Granular Cotton" (product name) manufactured by Japan Rock Wool Co., Ltd., "Locceram Granular Cotton" (product name) manufactured by JFE Rock Fiber Corporation, and "Pacific Mineral Fiber Granular Cotton" (product name) manufactured by Pacific Materials Corporation, can be suitably used. When such rock wool granular cotton is used, heat is less likely to be transmitted to the substrate covering the rock wool, providing thermal insulation, fire resistance, or non-combustibility, as well as sound absorption.

[0012] In the present invention, the rock wool composition is a composition containing rock wool and cement for rock wool compositions as main components.

[0013] The cement clinker powder mainly composed of calcium silicate in the present invention refers to a cement clinker powder containing 50% by mass or more of calcium silicate minerals (C3S, C2S) in the ground cement clinker. Cement clinker powder containing 60% by mass or more of calcium silicate minerals is preferred because it results in a high strength rock wool composition, and cement clinker powder containing 70% by mass or more of calcium silicate minerals is more preferred. Cement clinker powder used in ordinary Portland cement, high-early-strength Portland cement, ultra-high-early-strength Portland cement, or ecocement is preferred because it is easily available and has stable performance. The fineness of the cement clinker powder mainly composed of calcium silicate used in the present invention is a Blaine specific surface area of ​​2000 to 12000 cm 2 / g is preferred because the rock wool composition has high strength and a long usable time from the start of hydration. 2 If the viscosity is less than 12000 cm / g, the reactivity of hydration is low and the strength of the rock wool composition may be low. 2 If the pore size exceeds 1 / g, the usable time from the start of hydration of the rock wool composition is short, and there is a risk that construction will be difficult. Since the rock wool composition has high strength and a long usable time from the start of hydration, the fineness of the cement clinker powder containing calcium silicate as the main component used in the present invention is set to 2500 to 8000 cm in terms of Blaine specific surface area. 2 / g is more preferable, and 3000 to 6000 cm 2 As the cement clinker powder containing calcium silicate as a main component used in the present invention, ordinary Portland cement, high-early-strength Portland cement, ultra-high-early-strength Portland cement, or ecocement containing gypsum or the like may be used, and it is preferable to use these because they are easily available.

[0014] As the admixture in the present invention, it is preferable to use one or more of blast furnace slag as specified in JIS R 5211 "Blast furnace cement," siliceous admixture as specified in JIS R 5212 "Silica cement," fly ash as specified in JIS R 5213 "Fly ash cement" (collectively referred to as "JIS admixtures"), and powders of minerals having compositions similar to these, with JIS admixtures being more preferable.

[0015] The iron content of the cement for rock wool compositions of the present invention is 2.4% by mass or less, calculated as Fe2O3. If the iron content exceeds 2.4% by mass, the color difference between the rock wool and the cement hydrate becomes large, and the surface of the hardened rock wool composition (fiber layer) is prone to becoming uneven. Since the color difference between the rock wool and the cement hydrate on the surface of the hardened rock wool composition (fiber layer) is difficult to distinguish and the surface of the hardened rock wool composition (fiber layer) is less likely to become uneven, the iron content of the cement for rock wool compositions of the present invention is preferably 2.3% by mass or less, calculated as Fe2O3, and more preferably 2.0% by mass or less. Considering the iron content in cement clinker powder, which is primarily composed of calcium silicate, the strength of the hardened rock wool composition is high. Therefore, the iron content of the cement for rock wool compositions of the present invention is preferably 0.5% by mass or more, calculated as Fe2O3, more preferably 0.55% by mass or more, and even more preferably 0.58% by mass or more.

[0016] In the present invention, since the surface of the hardened rock wool composition (fiber layer) is less likely to become uneven and the hardened rock wool composition has high strength, the content of the cement clinker powder is preferably 1 to 90 mass% and the content of the admixture is 99 to 10 mass%, more preferably 1 to 85 mass% and 99 to 15 mass% of the admixture, still more preferably 1 to 80 mass% and 99 to 20 mass% of the admixture, and most preferably 5 to 70 mass% and 95 to 30 mass% of the admixture.

[0017] The cement for rock wool compositions of the present invention may contain one or more additive materials (admixtures) within the scope of not impairing the effects of the present invention. Examples of additive materials (admixtures) include thickeners, cement dispersants, expansive agents, waterproofing agents, rust inhibitors, shrinkage reducing agents, pigments, fibers other than rock wool, water repellents, efflorescence inhibitors, quick-setting additives (agents), quick-hardening additives (agents), setting retarders, foaming agents, antifoaming agents, gypsum, water repellents, and surface hardeners.

[0018] The rock wool composition of the present invention is characterized by containing rock wool, the cement for rock wool composition, and water as main components. The rock wool is the rock wool described above.

[0019] The rock wool composition of the present invention may be produced by simultaneously mixing rock wool, cement for rock wool composition, and water, or by adding each or some of the materials separately and then combining the added materials. Alternatively, the rock wool composition of the present invention may be produced by pre-mixing rock wool and cement for rock wool composition, or cement for rock wool composition and water, using a mixer or the like, and then adding the remaining materials to the mixture, or by adding the mixture to the remaining materials. Suitable examples include a method of adding water to a dry-mixed mixture of rock wool and cement for rock wool composition, a method of adding a cement slurry prepared by mixing cement for rock wool composition and water to rock wool, and a method of adding a cement slurry prepared by mixing the remainder of the cement for rock wool composition and water to a dry-mixed mixture of a portion of the cement for rock wool composition and rock wool. Production by a spraying method using a spraying device used for semi-dry construction, such as the schematic diagram shown in Figure 1, is preferred because it allows the rock wool composition of the present invention to be efficiently applied to pillars, beams, walls, ceilings, etc.

[0020] Because the rock wool composition of the present invention has high strength, it is preferable that the rock wool content be 20 to 95 parts by mass, the cement content be 80 to 5 parts by mass, and the water content be 40 to 150 parts by mass, per 100 parts by mass of the total of the rock wool and the cement for the rock wool composition, and more preferably the rock wool content be 30 to 90 parts by mass, the cement content be 70 to 10 parts by mass, and the water content be 60 to 120 parts by mass. Here, the water content includes the water of crystallization in the rock wool composition.

[0021] The rock wool composition of the present invention may contain one or more additive materials, provided that the effects of the present invention are not impaired. Examples of such additive materials include thickeners, cement dispersants, expansive additives, waterproofing agents, rust inhibitors, shrinkage reducing agents, pigments, fibers other than rock wool, water repellents, efflorescence inhibitors, quick-setting additives, quick-hardening additives, setting retarders, foaming agents, antifoaming agents, gypsum, water repellents, and surface hardeners, as well as aggregates such as silica sand, crushed sand, and artificial lightweight fine aggregate. [Example]

[0022] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0023] Cement for rock wool compositions (Test Nos. 1 to 8) was prepared according to the blending ratios shown in Table 1. The cement for rock wool composition in Test No. 1 was ordinary Portland cement, while the cement for rock wool composition in Test No. 8 was blast furnace slag powder. The rock wool composition was prepared by weighing 100 parts by mass of the prepared cement for rock wool composition, 150 parts by mass of rock wool, and 200 parts by mass of water, placing them in a plastic bag, and then mixing them in the bag. The prepared rock wool composition was poured into a mold to prepare a cubic rock wool composition specimen measuring 30 x 30 x 30 mm. The prepared specimen was cured in a constant humidity chamber at 20°C and 60% RH with only the top surface open until the measured age. The materials used are listed below. Table 1 also shows the compositional ratios of the rock wool composition and the cement for rock wool composition, as well as the iron content of the cement for rock wool composition in terms of Fe2O3. In all of the rock wool compositions of Test Nos. 1 to 8, the rock wool content was 60 parts by mass, the cement content for the rock wool composition was 40 parts by mass, and the water content was 80 parts by mass, relative to a total of 100 parts by mass of rock wool and cement for the rock wool composition. Rockwool: Rockwool granules manufactured by Pacific Materials Co., Ltd., symbol: RW Ordinary Portland cement: manufactured by Taiheiyo Cement Corporation, symbol: OPC Blast furnace slag powder (admixture): Blast furnace slag powder (granulated blast furnace slag 4000, Blaine specific surface area: 4130 cm 2 / g), symbol: BSF Water: Waterworks in Sakura City, Chiba Prefecture, symbol: W

[0024] [Table 1]

[0025] <Evaluation test> As an evaluation test of the produced rock wool composition, the surface of the test specimen was observed and a strength test was carried out to evaluate it. Surface observation of the test specimen The 14-day-old specimens were evaluated for visual observation of color unevenness, and the surface of the specimen was photographed. The brightness of the binder (cement hydrate) and rock wool portions was evaluated using a color sample (Japan Paint Manufacturers Association: Standard Colors for Paints). Note that neither the binder nor the rock wool portions of the specimen surface had any saturation. Cases where color unevenness could not be observed visually were rated "excellent" (symbol: ○), and cases where color unevenness could be observed were rated "poor" (symbol: ×). Strength testing For a one-day-old specimen, the stress was measured when a 4mm displacement was applied from the surface of the specimen in the compression direction using a push-pull gauge to confirm whether the shape was maintained. The stress when a 4mm displacement was applied was 4.0N / cm 2 If the above condition and shape are maintained, it is rated as "Excellent" (symbol: ○), and if the stress when a displacement of 4 mm is applied is 4.0 N / cm 2 If the thickness was less than 1 / 2 mm or the shape could not be maintained, the sample was evaluated as "poor" (symbol: x).

[0026] The results of the evaluation test are shown in Table 2. Also, a photograph of the surface observation of the test specimen is shown in Figure 2.

[0027] [Table 2]

[0028] The rock wool compositions of Test Nos. 1 and 2 had mottled surfaces after hardening, but the other rock wool compositions (Test Nos. 3 to 8) did not have mottled surfaces after hardening. In addition, the rock wool compositions of Test Nos. 1 to 7 were evaluated as excellent in the strength test, with a stress of 4.0 N / cm when subjected to a displacement of 4 mm. 2 In other words, the rock wool compositions of Test Nos. 3 to 7, which correspond to examples of the present invention, had no visible spots on the surface after hardening (no spots) and were excellent in strength. [Industrial Applicability]

[0029] The present invention can be suitably applied to coating the surface of components of structures or constructions made of concrete, steel, wood, etc., for the purpose of imparting heat insulation to the components, and can also be suitably applied to filling the interior of the components. [Explanation of symbols]

[0030] 1 Spray gun (center gun) 2 Granular rock wool nozzle 3. Binder slurry injection nozzle 4. Binder Slurry 5. Disintegrated granular rock wool 6. Binder slurry pressure feed hose 7. Pressure pump for binder slurry 8. Storage tank for binder slurry 9 Granular rock wool pressure feed hose 10 Spraying equipment (spraying system) 11 Granular rock wool (granular rock wool cotton) 12. A fibrous layer consisting of a mixture of granular rock wool and binder slurry (rock wool composition) 13 Base (wall) 14 Blower 15 Suction hose for binder slurry 20 Cotton opening machine 21 First Cotton Decomposition Department 22 Second cotton opening section 23 Hopper 24 Screw feeder 25 Rotary feeder (quantitative feeder) 26 Granular rock wool pressure pipe

Claims

1. The main components are cement clinker powder, which is mainly composed of calcium silicate, and admixtures, and the iron content is Fe ２ O ３ A cement for rock wool compositions characterized in that the converted cement content is 2.4 mass% or less.

2. The cement for rock wool compositions according to claim 1, wherein the content of the cement clinker powder is 1 to 90% by mass and the content of the admixture is 99 to 10% by mass.

3. A rock wool composition comprising rock wool, the cement for rock wool compositions according to claim 1 or 2, and water as main components.

4. The rock wool composition according to claim 3, wherein the content of rock wool is 20 to 95 parts by mass, the content of cement for rock wool composition according to claim 1 or 2 is 80 to 5 parts by mass, and the content of water is 40 to 150 parts by mass, relative to a total of 100 parts by mass of rock wool and cement for rock wool composition.

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