Gypsum concrete based on high-temperature gypsum-based cementing material and preparation method thereof

Abstract

The invention relates to gypsum concrete based on a high-temperature gypsum-based cementing material and a preparation method of the gypsum concrete, and belongs to the technical field of building materials. The raw material formula of the gypsum concrete comprises the following components in parts by weight: 50-70 parts of CaSO4 II-E high-temperature gypsum; 8 to 12 parts of building gypsum; 0.5 to 2 parts of a sulfate activator; 1-4 parts of an alkaline activator; 15 to 30 parts of aggregate; 5 to 10 parts of an active admixture; 0.5 to 1.5 parts of polypropylene fiber with the length of 6 to 12mm; 0.3 to 0.5 part of a polycarboxylic acid type water reducing agent; 0.05 to 0.1 part of a retarder; and 1-2 parts of an organosilane emulsion waterproof agent. The invention has the advantages of low cost, good comprehensive performance and wide application.

Description

Technical Field

[0001] The present invention relates to a gypsum concrete based on a high-temperature gypsum-based cementitious material and a preparation method thereof, belonging to the technical field of building materials. Background Art

[0002] High-temperature gypsum refers to high-temperature gypsum (CaSO4Ⅱ-E) produced by calcining at a temperature exceeding 700℃ - 900℃. Natural gypsum and industrial by-product gypsum are the main raw materials for the production of high-temperature gypsum. Industrial by-product gypsum has a wide source, low price and environmental protection. Using industrial by-product gypsum to produce high-temperature gypsum is beneficial to the consumption of industrial by-product gypsum.

[0003] Gypsum concrete with good comprehensive performance can be used for indoor floors, cast-in-place roof slabs, floor slabs, underground filling, and precast components. Among them, underground filling needs to have rapid initial setting (to prevent segregation), long-term stability (compressive strength ≥ 3 - 5MPa) and environmental protection. For precast components, such as lightweight partition boards, the dry density ≤ 1000kg / m 3 , and the compressive strength ≥ 15MPa.

[0004] Patent CN119430840A discloses a type II anhydrous gypsum ready-mixed concrete and a preparation method thereof. The type II anhydrous gypsum ready-mixed concrete is composed of the following raw materials in parts by weight: 25 - 28 parts of type II anhydrous gypsum, 5 - 7 parts of hemihydrate gypsum powder, 1.2 - 1.6 parts of calcium silicate, 0.2 - 0.5 parts of an admixture, 7 - 11 parts of water, 29 - 35 parts of crushed stone, and 28 - 32 parts of mountain sand. Using up to 95% or more of phosphogypsum, the setting time can be controlled and easily adjusted. It has high early strength, wear resistance, corrosion resistance and other properties. However, it cannot make large-scale use of industrial by-product gypsum, and the strength is low.

[0005] Patent CN112552011A discloses a high-temperature gypsum ordinary concrete and a preparation method thereof, aiming to end the "zero application" status of high-temperature anhydrous gypsum in the field of concrete. The material composition of the high-temperature gypsum ordinary concrete, based on the mass of high-temperature anhydrous gypsum, the mass fractions of each component include: 1 part of high-temperature anhydrous gypsum, 0.8 - 2 parts of admixture, 3 - 5 parts of fine aggregate, 5 - 7 parts of coarse aggregate, 0.6 - 1 part of water, 0.02 - 0.06 parts of an admixture; the admixture is Portland cement and pulverized coal. However, it cannot make large-scale use of industrial by-product gypsum, and the strength is low. In addition, it mainly relies on Portland cement and pulverized coal as cementitious materials and cannot be completely regarded as gypsum concrete. Summary of the Invention

[0006] The first object of the present invention is to provide a gypsum concrete based on a high-temperature gypsum-based cementitious material.

[0007] To achieve the above first object of the present invention, the raw material formula of the gypsum concrete includes, by weight:

[0008] CaSO4Ⅱ-E high-temperature gypsum: 50-70 parts;

[0009] Building gypsum: 8-12 parts;

[0010] Sulfate activator: 0.5-2 parts;

[0011] Alkaline activator: 1-4 parts;

[0012] Aggregate: 15-30 parts;

[0013] Active admixture: 5-10 parts;

[0014] Polypropylene fiber with a length of 6-12 mm: 0.5-1.5 parts;

[0015] Polycarboxylate-based water reducer: 0.3-0.5 parts;

[0016] Retarder: 0.05-0.1 parts;

[0017] Organosilane emulsion waterproofing agent: 1-2 parts.

[0018] In a specific embodiment, the fineness of the CaSO4Ⅱ-E high-temperature gypsum is 80-150 mesh; preferably, the particle size of the aggregate ≤ 10 mm.

[0019] In a specific embodiment, the sulfate activator includes at least one of potassium sulfate and sodium sulfate; the alkaline activator includes at least one of lime and cement; the aggregate is machine-made sand or natural sand; the active admixture is slag powder, silica fume or fly ash; the retarder includes at least one of bone glue and sodium citrate; preferably, the coarse aggregate of the aggregate is 5-10 mm, the fine aggregate ≤ 5 mm, and the fineness modulus is 2.3-2.6; more preferably, the coarse aggregate: accounts for 9-17 parts; the fine aggregate: accounts for 6-13 parts.

[0020] In a specific embodiment, the compressive strength of the gypsum concrete ≥ 20 MP; preferably, the compressive strength ≥ 30.5 MPa.

[0021] In a specific embodiment, the density of the gypsum concrete is 2.05 g / cm 3 ~2.15 g / cm 3 ; the softening coefficient Ks ≥ 0.8; preferably, there is no mass loss after 25 freeze-thaw cycles; more preferably, the setting time is 210-240 min.

[0022] In a specific embodiment, the preparation method of the gypsum concrete includes:

[0023] a. Dry-mix CaSO4Ⅱ-E high-temperature gypsum, building gypsum, active admixture and activator evenly to obtain mixed material A;

[0024] b. Add mixed material A to aggregate and polypropylene fiber and dry-mix evenly to obtain mixed material B;

[0025] c. Divide the aqueous solution containing organosilane emulsion waterproofing agent, water reducing agent and retarder into 3 portions and stir and add them to mixed material B in three times to form a homogeneous body;

[0026] d. Use vibration molding for the homogeneous body described in step c, and perform natural curing after molding: dry at room temperature for 7 days to obtain gypsum concrete.

[0027] In a specific embodiment, the time for dry-mixing evenly in step a is 3 minutes; the time for dry-mixing evenly in step b is preferably 5 minutes.

[0028] In a specific embodiment, the aqueous solution containing water reducing agent and retarder in step c is: mix dry materials with water, and the addition amount of water is 25-35% of the mass of dry materials, and the dry materials are the sum of all solid materials.

[0029] In a specific embodiment, the vibration frequency of the vibration molding in step d is 50 Hz, the amplitude is 0.5 mm, and the bubbles are removed by vibrating for 30-60 s.

[0030] The second object of the present invention is to provide a preparation method of gypsum concrete based on high-temperature gypsum-based cementitious materials.

[0031] To achieve the second object of the present invention, the preparation method of the gypsum concrete includes:

[0032] a. Dry-mix CaSO4Ⅱ-E high-temperature gypsum, building gypsum, active admixture and activator evenly to obtain mixed material A;

[0033] b. Add mixed material A to aggregate and polypropylene fiber and dry-mix evenly to obtain mixed material B;

[0034] c. Divide the aqueous solution containing organosilane emulsion waterproofing agent, water reducing agent and retarder into 3 portions and stir and add them to mixed material B in three times to form a homogeneous body;

[0035] d. Use vibration molding for the homogeneous body described in step c, and perform natural curing after molding: dry at room temperature for 7 days to obtain gypsum concrete;

[0036] The time for dry-mixing evenly in step a is preferably 3 minutes; the time for dry-mixing evenly in step b is preferably 5 minutes;

[0037] Preferably, the aqueous solution containing a water reducing agent and a retarder in step c is prepared by mixing dry materials with water, wherein the addition amount of water is 25-35% of the mass of the dry materials, and the dry materials are the sum of all solid materials;

[0038] Preferably, the vibration frequency of the vibration molding in step d is 50 Hz, the amplitude is 0.5 mm, and air bubbles are removed for 30-60 s.

[0039] Beneficial effects:

[0040] The raw materials of the gypsum concrete of the present invention are widely sourced and low in cost.

[0041] The gypsum concrete of the present invention has good comprehensive performance and is suitable for indoor floors (replacing cement concrete, compressive strength ≥ 20 MP), cast-in-place roof slabs (density ≤ 900 kg / m 3 ), floor slabs, underground filling (underground filling requires rapid initial setting, preventing segregation, long-term stability, compressive strength ≥ 3-5 MPa, environmental protection), precast components: lightweight partition boards (dry density ≤ 1000 kg / m 3 , compressive strength ≥ 15 MPa). Specific embodiments

[0042] To achieve the above first object of the present invention, the raw material formula of the gypsum concrete includes, by weight:

[0043] CaSO4Ⅱ-E high-temperature gypsum: 50-70 parts;

[0044] Building gypsum: 8-12 parts;

[0045] Sulfate activator: 0.5-2 parts;

[0046] Alkaline activator: 1-4 parts;

[0047] Aggregate: 15-30 parts;

[0048] Active admixture: 5-10 parts;

[0049] Polypropylene fiber with a length of 6-12 mm: 0.5-1.5 parts;

[0050] Polycarboxylate water reducing agent: 0.3-0.5 parts;

[0051] Retarder: 0.05-0.1 parts;

[0052] Organosilane emulsion waterproofing agent: 1-2 parts.

[0053] In a specific embodiment, the fineness of the CaSO4Ⅱ-E high-temperature gypsum is 80-150 mesh; preferably, the particle size of the aggregate is ≤ 10 mm.

[0054] In a specific embodiment, the sulfate activator includes at least one of potassium sulfate and sodium sulfate; the alkaline activator includes at least one of lime and cement; the aggregate is machine-made sand or natural sand; the active admixture is slag powder, silica fume or fly ash; the retarder includes at least one of bone glue and sodium citrate; preferably, the coarse aggregate of the aggregate is 5-10 mm, the fine aggregate is ≤5 mm, and the fineness modulus is 2.3-2.6; more preferably, the coarse aggregate: accounts for 9-17 parts; the fine aggregate: accounts for 6-13 parts.

[0055] In a specific embodiment, the compressive strength of the gypsum concrete ≥20MP; preferably, the compressive strength ≥30.5MPa.

[0056] In a specific embodiment, the density of the gypsum concrete is 2.05g / cm 3 ~2.15g / cm 3 ; the softening coefficient Ks≥0.8; preferably, there is no mass loss after 25 freeze-thaw cycles; more preferably, the setting time is 210-240min.

[0057] In a specific embodiment, the preparation method of the gypsum concrete includes:

[0058] a. Dry-mix CaSO4Ⅱ-E high-temperature gypsum, building gypsum, active admixture and activator evenly to obtain a mixed material A;

[0059] b. Add the mixed material A to the aggregate and polypropylene fiber and dry-mix evenly to obtain a mixed material B;

[0060] c. Divide the aqueous solution containing organosilane emulsion waterproofing agent, water reducer and retarder into 3 portions and stir and add them to the mixed material B three times to form a homogeneous body;

[0061] d. Vibration-mold the homogeneous body obtained in step c, and perform natural curing after molding: dry at room temperature for 7 days to obtain gypsum concrete.

[0062] In a specific embodiment, the time for dry-mixing evenly in step a is 3 minutes; the time for dry-mixing evenly in step b is preferably 5 minutes.

[0063] In a specific embodiment, the aqueous solution containing water reducer and retarder in step c is: mix dry materials with water, and the addition amount of water is 25-35% of the mass of the dry materials, and the dry materials are the sum of all solid materials.

[0064] In a specific embodiment, the vibration frequency of the vibration molding in step d is 50Hz, the amplitude is 0.5mm, and the bubbles are excluded for 30-60s.

[0065] To achieve the second object of the present invention, the preparation method of the gypsum concrete includes:

[0066] a. Dry-mix CaSO4Ⅱ-E high-temperature gypsum, building gypsum, active admixture and activator evenly to obtain mixed material A;

[0067] b. Add mixed material A to aggregate and polypropylene fiber and dry-mix evenly to obtain mixed material B;

[0068] c. Divide the aqueous solution containing organosilane emulsion waterproofing agent, water reducer and retarder into 3 portions and stir and add them to mixed material B in three times to form a homogeneous body;

[0069] d. Vibration mold the homogeneous body obtained in step c, and perform natural curing after molding: dry at room temperature for 7 days to obtain gypsum concrete;

[0070] The preferred time for dry-mixing evenly in step a is 3 minutes; the preferred time for dry-mixing evenly in step b is 5 minutes;

[0071] Preferably, the aqueous solution containing water reducer and retarder in step c is: mix dry materials with water, the addition amount of water is 25-35% of the mass of dry materials, and the dry materials are the sum of all solid materials;

[0072] Preferably, the vibration frequency of the vibration molding in step d is 50 Hz, the amplitude is 0.5 mm, and the bubbles are removed for 30-60 s.

[0073] The following further describes the specific implementation manners of the present invention in conjunction with embodiments, and the present invention is not limited to the scope of the described embodiments.

[0074] Example 1

[0075] The dihydrate gypsum is calcined at 700-900 °C and then rapidly cooled and modified and ground into high-temperature gypsum (CaSO4Ⅱ-E) with a fineness of 80-150 meshes; weigh 52 parts of high-temperature gypsum (CaSO4Ⅱ-E), 10 parts of building gypsum, 0.6 part of sulfate activator, 3 parts of alkaline activator Portland cement, 30 parts of aggregate, of which coarse aggregate: accounts for 17 parts; fine aggregate: accounts for 13 parts, 5 parts of silica fume, 0.5 part of polypropylene fiber with a length of 6-12 mm, 0.06 part of sodium citrate, 1.4 parts of organosilane emulsion, 0.4 part of polycarboxylic acid system.

[0076] Feed in steps: first dry-mix the high-temperature gypsum, building gypsum, active admixture and activator for 3 min → add aggregate and fiber and dry-mix for 5 min.

[0077] Pre-dissolve silicone alkane emulsion waterproofing agent, water reducing agent, retarder, etc. in water. The addition amount of water is 30% of the mass of dry materials, and it is added to the mixer in three times for wet mixing control. Vibration molding: frequency 50Hz, amplitude 0.5mm, lasting for 30 - 60s to remove air bubbles.

[0078] Wet heat curing: Keep moist and cure naturally for 7 days.

[0079] Refer to European Standard EN 1795-1:2020 "Building Gypsum Products - Part 1: Classification, Specifications and Performance Requirements"

[0080] Among them, the classification of gypsum concrete:

[0081] Type Density (g / cm 3 ) Compressive strength (MPa)

[0082] Solid gypsum concrete 1.8 - 2.2 20 - 30

[0083] Lightweight gypsum concrete 1.2 - 1.6 3 - 8

[0084] Other indicators:

[0085] Thermal resistance value (R-value): ≥0.22 (m 2 ·K) / W (for 100mm thickness).

[0086] Fire resistance rating: Class A2 (limiting oxygen index LOI ≥ 28).

[0087] Mechanical property targets

[0088] Compressive strength: Classified according to usage:

[0089] Non-load-bearing structure: Compressive strength at 28d ≥ 15MPa;

[0090] Ground load-bearing structure: Compressive strength at 28d ≥ 20MPa, and can be divided into grades G20, G30, G40.

[0091] Flexural strength: Flexural strength at 28d ≥ 8MPa.

[0092] Durability and workability

[0093] Water resistance: Softening coefficient ≥ 0.6, ≥ 0.8 after modification.

[0094] Shrinkage rate: Drying shrinkage rate at 28d ≤ 0.05%.

[0095] Workability: Spread (slump) controlled at 160 - 180mm.

[0096] Test methods

[0097] Mechanical property test: Refer to GB / T 17671-2021 (Test method for cement mortar strength).

[0098] Water resistance test: Refer to JC / T 547-2017 (Water resistance test of gypsum-based materials).

[0099] Long-term performance: Accelerated aging experiments such as carbonation and freeze-thaw cycles need to be designed.

[0100] After testing, the products of Examples 1-3 all meet the standard requirements.

[0101] Example 2

[0102] Dihydrate gypsum is calcined at 700-900 °C, rapidly cooled, modified, ground into high-temperature gypsum (CaSO4Ⅱ-E) with a fineness of 80-150 mesh; 60 parts of high-temperature gypsum (CaSO4Ⅱ-E), 10 parts of building gypsum, 0.7 part of sulfate activator, 3 parts of alkaline activator Portland cement, 22 parts of aggregate, among which coarse aggregate: accounting for 13 parts; fine aggregate: accounting for 9 parts, 5 parts of silica fume, 0.5 part of polypropylene fiber with a length of 6-12 mm, 0.06 part of sodium citrate, 1.4 parts of organosilane emulsion, 0.4 part of polycarboxylate series are weighed. Press and form by vibration according to the above process formula, and measure after natural curing for 7 days.

[0103] Example 3

[0104] Dihydrate gypsum is calcined at 700-900 °C, rapidly cooled, modified, ground into high-temperature gypsum (CaSO4Ⅱ-E) with a fineness of 80-150 mesh; 67 parts of high-temperature gypsum (CaSO4Ⅱ-E), 10 parts of building gypsum, 0.8 part of sulfate activator, 3 parts of alkaline activator Portland cement, 15 parts of aggregate, among which coarse aggregate: accounting for 9 parts; fine aggregate: accounting for 6 parts, 5 parts of silica fume, 0.5 part of polypropylene fiber with a length of 6-12 mm, 0.06 part of sodium citrate, 1.4 parts of organosilane emulsion, 0.4 part of polycarboxylate series are weighed. Press and form by vibration according to the above process formula, and measure after natural curing for 7 days.

[0105] Comparative Example 1

[0106] Dihydrate gypsum is calcined at 700-900 °C, rapidly cooled, modified, ground into high-temperature gypsum (CaSO4Ⅱ-E) with a fineness of 80-150 mesh; 45 parts of high-temperature gypsum (CaSO4Ⅱ-E), 10 parts of building gypsum, 0.6 part of sulfate activator, 3 parts of alkaline activator (Portland cement), 37 parts of aggregate (21 parts of coarse aggregate; 16 parts of fine aggregate), 5 parts of silica fume, 2.36 parts of admixture (0.5 part of polypropylene fiber with a length of 6-12 mm, 0.06 part of sodium citrate, 1.4 parts of organosilane emulsion, 0.4 part of polycarboxylate series) are weighed. Produce gypsum concrete with high-temperature gypsum by the above method.

[0107] Comparative Example 2

[0108] The dihydrate gypsum is calcined at 700 - 900 °C, rapidly cooled, modified and ground into high-temperature gypsum (CaSO4Ⅱ-E) with a fineness of 80 - 150 mesh; 28 parts of high-temperature gypsum (CaSO4Ⅱ-E), 5 parts of building gypsum, 32 parts of coarse aggregate, 30 parts of fine aggregate, 1.5 parts of silica fume, 0.5 part of admixture (including: 7 parts of retarder, 3 parts of calcium formate, 34 parts of carboxylic acid reducer, 2 parts of rubber powder, 4 parts of cellulose, 3 parts of defoamer, 35 parts of calcium hydroxide, 2 parts of viscosity reducer), and 10 parts of water are weighed. Gypsum concrete is produced with high-temperature gypsum by the above method.

[0109] Comparative Example 3

[0110] The dihydrate gypsum is calcined at 700 - 900 °C, rapidly cooled, modified and ground into high-temperature gypsum (CaSO4Ⅱ-E) with a fineness of 80 - 150 mesh; 1 part of high-temperature gypsum (CaSO4Ⅱ-E), 6 parts of building gypsum, 1.5 parts of admixture (portland cement), 6 parts of coarse aggregate, 4 parts of fine aggregate, 1.5 parts of silica fume, 0.05 part of admixture (polycarboxylate superplasticizer), and 0.8 part of water are weighed. Gypsum concrete is produced with high-temperature gypsum by the above method.

[0111] The measurement results of Examples 1 - 3 and Comparative Examples 1 - 3 are shown in Table 1 in detail.

[0112] Table 1 Experiments on Producing Gypsum Concrete with High-Temperature Gypsum

[0113]

Claims

1. Gypsum concrete based on high-temperature gypsum-based cementitious materials, characterized in that The raw material formula of the gypsum concrete includes, by weight: CaSO4Ⅱ-E high-temperature gypsum: 50 to 70 parts; Building gypsum: 8 to 12 parts; Sulfate activator: 0.5 to 2 parts; Alkaline activator: 1 to 4 parts; Aggregate: 15 to 30 parts; Active admixture: 5 to 10 parts; Polypropylene fiber with a length of 6 to 12 mm: 0.5 to 1.5 parts; Polycarboxylate-based water reducer: 0.3 to 0.5 parts; Retarder: 0.05 to 0.1 parts; Organosilane emulsion waterproofing agent: 1 to 2 parts.

2. The gypsum concrete based on a high-temperature gypsum-based cementitious material according to claim 1, characterized in that, The fineness of the CaSO4Ⅱ-E high-temperature gypsum is 80 to 150 mesh; preferably, the particle size of the aggregate ≤ 10 mm.

3. The gypsum concrete based on the high-temperature gypsum-based cementing material according to claim 1 or 2, characterized in that The sulfate activator includes at least one of potassium sulfate and sodium sulfate; the alkaline activator includes at least one of lime and cement; the aggregate is machine-made sand or natural sand; the active admixture is slag powder, silica fume or fly ash; the retarder includes at least one of bone glue and sodium citrate; preferably, the coarse aggregate of the aggregate is 5 to 10 mm, the fine aggregate ≤ 5 mm, and the fineness modulus is 2.3 to 2.6; more preferably, the coarse aggregate: accounts for 9 to 17 parts; the fine aggregate: accounts for 6 to 13 parts.

4. The gypsum concrete based on a high-temperature gypsum-based cementitious material according to claim 1 or 2, characterized in that, The compressive strength of the gypsum concrete ≥ 20 MP; preferably, the compressive strength ≥ 30.5 MPa.

5. The gypsum concrete based on a high-temperature gypsum-based cementitious material according to claim 1 or 2, characterized in that, The density of the gypsum concrete is 2.05 g / cm 3 ~2.15 g / cm 3 ; the softening coefficient Ks ≥ 0.8; preferably, there is no mass loss after 25 freeze-thaw cycles; more preferably, the setting time is 210 - 240 min.

6. The gypsum concrete based on the high-temperature gypsum-based cementitious material according to claim 1 or 2, characterized in that, The preparation method of the gypsum concrete includes: a. Dry-mix the CaSO4Ⅱ-E high-temperature gypsum, building gypsum, active admixture and activator evenly to obtain a mixed material A; b. Add the mixed material A to the aggregate and polypropylene fiber and dry-mix evenly to obtain a mixed material B; c. Divide the aqueous solution containing the organosilane emulsion waterproofing agent, water reducer and retarder into 3 portions and stir and add them to the mixed material B three times to form a homogeneous body; d. Subject the homogeneous body obtained in step c to vibration molding, and perform natural curing after molding: dry at room temperature for 7 days to obtain gypsum concrete.

7. The gypsum concrete based on the high-temperature gypsum-based cementitious material according to claim 6, characterized in that The time for dry-mixing evenly in step a is 3 minutes; the time for dry-mixing evenly in step b is preferably 5 minutes.

8. The gypsum concrete based on a high-temperature gypsum-based cementitious material according to claim 6, characterized in that, The aqueous solution containing the water reducer and retarder in step c is: mix the dry materials with water, and the addition amount of water is 25 to 35% of the mass of the dry materials, and the dry materials are the sum of all solid materials.

9. The gypsum concrete based on the high-temperature gypsum-based cementitious material according to claim 6, characterized in that, The vibration frequency of the vibration molding in step d is 50 Hz, the amplitude is 0.5 mm, and air bubbles are removed for 30 to 60 s.

10. The preparation method of gypsum concrete based on high-temperature gypsum-based cementitious materials according to any one of claims 1 to 9, characterized in that, The preparation method of the gypsum concrete includes: a. Dry-mix the CaSO4Ⅱ-E high-temperature gypsum, building gypsum, active admixture and activator evenly to obtain a mixed material A; b. Add the mixed material A to the aggregate and polypropylene fiber and dry-mix evenly to obtain a mixed material B; c. Divide the aqueous solution containing the organosilane emulsion waterproofing agent, water reducer and retarder into 3 portions and stir and add them to the mixed material B three times to form a homogeneous body; d. Subject the homogeneous body obtained in step c to vibration molding, and perform natural curing after molding: dry at room temperature for 7 days to obtain gypsum concrete; The time for dry-mixing evenly in step a is preferably 3 minutes; the time for dry-mixing evenly in step b is preferably 5 minutes; Preferably, the aqueous solution containing water reducing agent and retarder in step c is: mixing dry materials with water, the addition amount of water being 25-35% of the mass of the dry materials, and the dry materials being the sum of all solid materials; Preferably, the vibration frequency of the vibration molding in step d is 50 Hz, the amplitude is 0.5 mm, and the air bubbles are removed for 30-60 s.

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