Gypsum-based composition, gypsum slurry, and building member

Abstract

The invention provides a gypsum-based composition, which comprises the following components in parts by weight: 500 to 1000 parts of gypsum; 100 to 225 parts of aggregate; 50 to 225 parts of sepiolite fiber; 1 to 12 parts of cellulose; and at least 0.1 part of an additive. According to the invention, sepiolite is combined with a gypsum material to prepare the fireproof coating, so that the water-powder ratio is remarkably increased, the material is light, and the fireproof coating has excellent fire resistance, cracking resistance, shrinkage resistance and higher coverage rate.

Description

Gypsum-based compositions, gypsum slurries and building components Technical Field

[0001] This invention relates to building materials, and more particularly to gypsum-based compositions. Background Technology

[0002] In the construction industry, steel structures are the main load-bearing components. Although they are non-combustible materials, they have poor fire resistance, with a fire resistance limit of only 15 minutes under direct flame, which manifests as the building losing its support and collapsing. Therefore, fireproofing steel structures is extremely important. Among the methods, fire-retardant coatings are widely used due to their advantages such as ease of use, no shape restrictions, and excellent fire resistance. Summary of the Invention

[0003] The purpose of this invention is to provide a fireproof coating for building structures, particularly for steel structures.

[0004] Therefore, according to one aspect of the present invention, a gypsum-based composition comprises the following components in parts by weight: gypsum, 500-1000 parts; aggregate, 100-225 parts; sepiolite fiber, 50-225 parts; cellulose, 1-12 parts; and additives, at least 0.1 parts.

[0005] The gypsum is anhydrous gypsum, hemihydrate gypsum, dihydrate gypsum, or any combination thereof.

[0006] The aggregate is a lightweight aggregate, which is expanded perlite, expanded vermiculite, or a combination thereof.

[0007] The cellulose or its derivatives are selected from sodium carboxymethyl cellulose, methyl cellulose, hydroxyethyl methyl cellulose, and hydroxypropyl methyl cellulose.

[0008] The additives include an air-entraining agent and a retarder. Further, the air-entraining agent is 0.1-2 parts, selected from sodium dodecyl sulfate, sulfonylbenzene sulfonate, and fatty alcohol sulfonate. Further, the retarder is 0.1-5 parts, selected from lignin sulfonate, protein retarder, sodium hexametaphosphate, sodium polyphosphate, citric acid, sodium citrate, tartaric acid, potassium tartrate, acrylic acid, and sodium acrylate.

[0009] According to another aspect of the invention, a gypsum slurry comprises a gypsum composition as described above and water, wherein the weight ratio of the gypsum composition to water is 1:1-1.4.

[0010] According to another aspect of the invention, a building component has a building body, the surface of which is provided with a coating, the coating being formed by drying the aforementioned gypsum slurry.

[0011] Furthermore, under the conditions specified in the national standard GB 14907 "Fire-retardant Coatings for Steel Structures", the building components have a fire resistance performance of at least 3 hours.

[0012] This invention utilizes sepiolite fiber combined with gypsum material to prepare fire-retardant coatings, significantly improving the water-to-powder ratio, achieving lightweight materials, and exhibiting excellent fire resistance, crack resistance, shrinkage resistance, bending resistance, and high coverage. Detailed Implementation

[0013] The specific embodiments of the present invention are described below.

[0014] According to one embodiment of the present invention, the gypsum-based composition includes gypsum, aggregates, sepiolite fibers, cellulose or derivatives thereof, and additives.

[0015] The gypsum is present in an amount of 500-1000 parts by weight. In this invention, the gypsum may be hemihydrate gypsum, dihydrate gypsum, or a combination thereof. The gypsum may also be activated anhydrous gypsum. In examples using anhydrous gypsum, the anhydrous gypsum is usually partially activated; in this case, the unactivated anhydrous gypsum can be used as part of the aggregate.

[0016] The aggregate can be lightweight aggregate or heavy aggregate, coarse aggregate or fine aggregate, or a combination of multiple aggregates, with a total weight of 100-225 parts. Preferably, lightweight aggregate is used to achieve weight reduction, such as expanded perlite or expanded vermiculite.

[0017] Sepiolite fiber can be any suitable and commercially available material. The inventors of this application have found through experiments that currently commercially available sepiolite fiber products are all applicable to the technical solutions of this invention. The sepiolite fiber is present in parts by weight of 100-225.

[0018] The cellulose or its derivatives are present in parts by weight of 1-10 parts, used to improve the working performance of the product. The cellulose or its derivatives may be sodium carboxymethyl cellulose, methyl cellulose, hydroxyethyl methyl cellulose, or hydroxypropyl methyl cellulose, or, in some examples, any combination of the aforementioned chemicals.

[0019] Additives may include air-entraining agents and retarders, and may also include other suitable chemicals to achieve different functions, such as pigments, adhesion promoters, etc. The content of additives is at least 0.1 parts by weight, and the specific content of additives may be determined based on the specific chemical formulation used.

[0020] Furthermore, the air-entraining agent comprises 0.1-2 parts by weight, and may be sodium dodecyl sulfate, sulfonylbenzene sulfonate, or fatty alcohol sulfonate, or any combination thereof. The retarder comprises 0.1-5 parts by weight, and may be any one or any combination of lignin sulfonate, protein retarder, sodium hexametaphosphate, sodium polyphosphate, citric acid, sodium citrate, tartaric acid, potassium tartrate, acrylic acid, and sodium acrylate. The adhesion promoter comprises 0-40 parts by weight, and may be phenolic resin, redispersible latex powder, or a combination thereof.

[0021] According to another embodiment of the present invention, a gypsum slurry comprises the aforementioned gypsum composition and water, wherein the weight ratio of the gypsum composition to water is 1:1 to 1:1.4, that is, the water-to-gypsum ratio is 1 to 1.4.

[0022] According to another embodiment of the present invention, a building component has a building body with a coating on its surface, the coating being formed by drying the aforementioned gypsum slurry. Preferably, the building component body is a steel structure component. The building component has a fire resistance of at least 3 hours.

[0023] Example

[0024] Several embodiments are given below, and Table 1 lists the specific materials of each component in these embodiments.

[0025] The materials listed in Table 1 were mixed evenly according to the given weight proportions to obtain a powder mixture. Water was then added according to the water-to-solid ratio given in Table 2 to obtain a slurry. The resulting slurry was applied to the surface of the steel structure. Fire resistance performance tests were conducted according to the methods specified in national standard GB14907. The fire resistance test results for each embodiment are shown in Table 3.

[0026] Table 1

[0027]

[0028] Table 2

[0029] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Water-to-paste ratio: 1.35 1.40 1.20 1.10 1.15 1.00 surface

[0030] Table 3

[0031]

[0032] As shown in Table 3, the composition of this application has a low density, meeting the requirements for lightweighting. Simultaneously, the coating formed by the technical solution of this application exhibits high strength. Furthermore, the solution of this application meets the fire resistance performance requirements for 3 hours specified in the national standard GB 14907 "Fire-retardant Coatings for Steel Structures".

[0033] The above description illustrates the details of the technical solution of the present invention. However, those skilled in the art will understand that the present invention is not limited to the specific details listed in the above embodiments, but can be varied within the scope defined by the claims.

Claims

1. A gypsum-based composition comprising the following components in parts by weight: gypsum, 500-1000 parts; aggregate, 100-225 parts; sepiolite fiber, 50-225 parts; cellulose, 1-12 parts; and additives, at least 0.1 parts.

2. The gypsum composition according to claim 1, characterized in that, The gypsum is anhydrous gypsum, hemihydrate gypsum, dihydrate gypsum, or any combination thereof.

3. The gypsum composition according to claim 1, characterized in that, The aggregate is lightweight aggregate, which is expanded perlite, expanded vermiculite, or a combination thereof.

4. The gypsum composition according to claim 1, characterized in that, The cellulose or its derivatives are selected from sodium carboxymethyl cellulose, methyl cellulose, hydroxyethyl methyl cellulose, and hydroxypropyl methyl cellulose.

5. The gypsum composition according to claim 1, characterized in that, The additives include air-entraining agents and retarders.

6. The gypsum composition according to claim 5, characterized in that, The air-entraining agent is 0.1-2 parts, and it is selected from sodium dodecyl sulfate, sulfonylbenzene sulfonate, and fatty alcohol sulfonate.

7. The gypsum composition according to claim 5, characterized in that, The retarder is 0.1-5 parts, and is selected from lignin sulfonate, protein retarder, sodium hexametaphosphate, sodium polyphosphate, citric acid, sodium citrate, tartaric acid, potassium tartrate, acrylic acid, and sodium acrylate.

8. A gypsum slurry comprising a gypsum composition as described in any one of claims 1-7 and water, wherein the weight ratio of the gypsum composition to water is 1:1-1.

4.

9. A building component having a building body, characterized in that, The building body is provided with a coating, which is formed by drying the gypsum slurry as described in claim 8.

10. The building component as claimed in claim 1, characterized in that, The building components have a fire resistance of at least 3 hours.

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