Preparation method of beehive manufacturing material

Abstract

The invention relates to a preparation method of a beehive manufacturing material. The preparation method comprises the following steps: S1, pretreating fir sawdust; s2, mixing Portland cement, fly ash and nano silicon dioxide; s3, expanded perlite is added after the step S2, and stirring treatment is performed; s4, after the step S3, the fir sawdust pretreated in the step S1 is added and stirred; s5, adding polypropylene fibers after the step S4, and stirring; s6, after the step S5, a water repellent and water mixed solution is added and stirred; s7, injection molding is conducted, and standing condensation is conducted; and S8, demolding and curing, and naturally drying to obtain the beehive manufacturing material. The Chinese fir sawdust is selected as a base material to be combined with the beewax, the Chinese fir sawdust is wide in source and low in cost, the whole body is light in weight due to the material of the Chinese fir sawdust, the mildew resistance is improved due to the combination of the Chinese fir sawdust and the beewax, the use amount of polypropylene fibers can be reduced in the whole process, the degradability of the material is improved, and the wood property of the Chinese fir sawdust and the high friendliness of bees are achieved; the beewax can simulate a natural honeycomb environment, so that honeybees are promoted to nest.

Description

Technical Field

[0001] The present invention relates to the technical field of manufacturing methods for beehive materials, and particularly to a preparation method for beehive materials. Background Art

[0002] Traditional beehives are mostly made of wood, but wooden beehives are prone to moisture, mildew, insect infestation, and have a short service life, resulting in high costs and low profits for large-scale breeding. Although cement beehives have good durability, they are heavy and have poor heat insulation, showing a situation of being cold in winter and hot in summer, which is not conducive to the reproduction and honey storage of bees, and bees have a low adaptability to cement materials.

[0003] Lightweight cement materials have appeared on the market for making beehives, but most lightweight cement materials are reinforced with bamboo fibers or polypropylene fibers. However, bamboo fibers have a high cost, and polypropylene fibers have poor ecological friendliness.

[0004] Therefore, existing wooden beehives, cement beehives, and lightweight cement beehives on the market all have their own disadvantages and deficiencies and need to be improved. Summary of the Invention

[0005] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a preparation method for beehive materials, which includes the following steps:

[0006] S1: Pretreatment of Chinese fir sawdust;

[0007] S2: Mix silicate cement, fly ash, and nano-silica;

[0008] S3: Add expanded perlite and stir after step S2;

[0009] S4: Add the pretreated Chinese fir sawdust in step S1 and stir after step S3;

[0010] S5: Add polypropylene fiber and stir after step S4;

[0011] S6: Add a mixture of a water repellent and water and stir after step S5;

[0012] S7: Inject into a mold and let it stand and solidify;

[0013] S8: Demold and cure, and naturally dry to obtain beehive materials.

[0014] In the present invention, a further embodiment is that in step S1, the pretreatment of Chinese fir sawdust is carried out in sequence according to the processes of screening, alkali solution neutralization, drying, mildew prevention treatment, and beeswax wrapping.

[0015] In the present invention, a further embodiment is to screen out cedar sawdust with a particle size of 2-3 mm from the cedar sawdust and remove impurities. The screening of the cedar sawdust is carried out through multi-stage screening. First, a vibrating screen with a 4-mm aperture is used to remove large particles, then a 2-mm standard screen is used for screening, and the cedar sawdust with a particle size of 2-3 mm is retained. The dust in the cedar sawdust is removed by air classification, and a magnetic separator is used to remove metal impurities in the cedar sawdust. A photoelectric sorter is used to identify and remove resin lumps.

[0016] In the present invention, a further embodiment is to neutralize the alkali solution in the cedar sawdust by soaking it in a 1% sodium hydroxide solution for 24 h, controlling the temperature at 60±5°C, and monitoring the pH value in real time to maintain the pH value between 11.5 and 12.0. When the pH value drops by more than 0.5, sodium hydroxide solution is replenished. The drying of the cedar sawdust is carried out by gradient drying. In the pre-drying stage, it is first dried under a hot air circulation at 80°C for 1 h, and then deep drying is carried out. Under deep drying, it is dried under vacuum at 50°C until the moisture content ≤5%, and it is weighed and monitored every 30 min. Finally, the dried cedar sawdust is placed in a constant humidity box to balance for 24 h. The constant humidity parameters of the constant humidity box are RH45% and a temperature of 25°C.

[0017] In the present invention, a further embodiment is to carry out anti-mildew treatment on the cedar sawdust by soaking it in a 0.5% borax solution. First, a 0.5% borax solution is compounded with 0.2% quaternary ammonium salt and soaked. It is soaked at 60°C for 2 h, and vacuum is pumped for 10 min while soaking.

[0018] In the present invention, a further embodiment is to wrap the cedar sawdust with beeswax by heating and melting the beeswax and evenly spraying it on the surface of the cedar sawdust. Beeswax and rosin are melted together in a mass ratio of 4:1, and 5% nano-titanium dioxide and 1% fluorosilane are added. It is evenly sprayed on the surface of the cedar sawdust by means of high-voltage electrostatic spraying. Finally, it is dried, cooled, and shaped with cold air at 5°C.

[0019] In the present invention, a further embodiment is that in step S2, portland cement, fly ash, and nano-silica are dry-mixed in a ratio of 40%-50%:15%-20%:2%-3% for 3 min, and dry-mixing treatment is carried out under nitrogen protection. The rotation speed of the mixer is controlled at 200±50 rpm, and the temperature is controlled ≤40°C. Before dry-mixing, the fly ash is first activated, and the activation is carried out by drying at 105±5°C for 2 h.

[0020] In the present invention, a further embodiment is that in step S3, expanded perlite is added and stirred at a medium speed for 2 min. The addition of expanded perlite is carried out in a gradient manner. First, half of the amount with a particle size of 1-3 mm is added and stirred for 1 min, and then the other half is added and stirred for 1 min. After the treatment in step S3, the pre-treated Chinese fir sawdust from step S1 is added and stirred at a low speed for 1 min.

[0021] In the present invention, a further embodiment is that in step S5, polypropylene fibers are added and stirred for 2 min. In step S6, a mixture of a water repellent and water is added. First, it is pre-heated to 50 °C, and then 0.1% defoamer is added and stirred at a high speed for 5 min.

[0022] In the present invention, a further embodiment is that in step S7, after adding calcium formate coagulant after step S6, it is injected into a mold. First, it is vibrated for 60 s and then left standing for 24 h. In step S8, after demolding, steam curing is carried out, cured at a temperature of 55 °C for 12 h, and naturally dried for 7 days, and a 5% potassium carbonate solution is sprayed once a day.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] The materials for making the beehive in this invention are different from the existing ones. Chinese fir sawdust is selected as the base material and combined with beeswax. The source of Chinese fir sawdust is extensive and the cost is low, which can greatly reduce the production cost. Moreover, its own wood material characteristics have a friendly aggregation effect on bees. After uniformly screening the Chinese fir sawdust by size, removing impurities, treating with alkali solution to neutralize lignin, and performing anti-mold treatment to improve the anti-mold property, finally, it is evenly sprayed with beeswax and shaped to complete the pretreatment of Chinese fir sawdust; preliminary dry mixing is carried out with Portland cement, fly ash and nano-silica, then expanded perlite is added to improve the heat insulation and fire prevention effects, then the pre-treated Chinese fir sawdust is added, then polypropylene fibers are added to enhance crack resistance and impermeability, then a water repellent is added to change the surface properties and improve the waterproof performance, and finally, it is injection-molded and cured and dried to become the material for making the beehive. The material of Chinese fir sawdust makes the whole lighter, and the combination with beeswax improves the anti-mold property. And the amount of polypropylene fibers can be reduced throughout the process, improving the degradability of the material. Due to the high friendliness of the wood characteristics of Chinese fir sawdust to bees, beeswax can simulate the natural honeycomb environment, thus promoting bees to build nests.

[0025] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. Description of the Drawings

[0026] Figure 1 It is a flow chart of a preparation method of a material for making a beehive. Specific Embodiments

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0028] Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation of the present invention.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0030] In the present invention, unless otherwise clearly specified and defined, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Embodiment 1

[0032] In this embodiment, a preparation method of bee box manufacturing materials is provided, including the following steps:

[0033] S1: Pretreatment of Chinese fir sawdust;

[0034] S2: Mix silicate cement, fly ash and nano-silica;

[0035] S3: Add expanded perlite and stir after step S2;

[0036] S4: Add the pretreated Chinese fir sawdust in step S1 and stir after step S3;

[0037] S5: Add polypropylene fiber and stir after step S4;

[0038] S6: After step S5, add a mixture of a water repellent and water and stir.

[0039] S7: Inject the mold and let it stand for coagulation.

[0040] S8: Demold and cure, and naturally dry to obtain the material for making beehives.

[0041] The biggest difference from the existing materials for making beehives is that instead of choosing traditional materials such as wood, cement, or lightweight cement, the anti - mildew property of wood materials is poor and the service life is short; the quality of cement is large and bees have poor adaptability to cement materials, which is not suitable for beehives; lightweight cement has a high cost, is not easily degradable, and is not environmentally friendly. In contrast, the base material of this embodiment selects cedar sawdust. Cedar sawdust is widely distributed and low - cost. At the same time, cedar sawdust also has the characteristics of wood. Bees have a relatively high adaptability to it, which can attract bees to build nests well, and it is also light in quality, which is conducive to lightweight design.

[0042] In this embodiment, in step S1, the pretreatment of cedar sawdust is carried out in the order of screening, alkali - liquid neutralization, drying, anti - mildew treatment, and beeswax wrapping.

[0043] In this embodiment, further, the screening of cedar sawdust screens out cedar sawdust with a particle size of 2 - 3 mm and removes impurities. The screening of cedar sawdust is carried out through multi - stage screening. First, a vibrating screen with a 4 - mm aperture is used to remove large - sized particles, then a 2 - mm standard screen is used for screening, and cedar sawdust with a particle size of 2 - 3 mm is retained. Air - flow separation is used to remove dust in cedar sawdust, and a magnetic separator is used to remove metal impurities in cedar sawdust. An optoelectronic sorter identifies and removes resin lumps. By removing dust, metal impurities, and resin lumps, it can ensure that cedar sawdust plays a synergistic role of lightweight, reinforcement, and functional modification in the composite material, while meeting the reliability requirements of industrial production.

[0044] Among them, dust will adhere to the surface of cedar sawdust, hindering its chemical bonding with the cement matrix. After removal, the coating effect of beeswax or coupling agent is more uniform, improving the interfacial strength between the fiber matrix (the tensile strength can be increased by 15 - 20%). Dust will block the natural pores of cedar sawdust, affecting the lightweight synergistic effect of expanded perlite. After removal, the porosity of the material is more controllable (the water absorption rate is reduced to ≤8%). Dust is easy to generate dust during stirring, polluting equipment and affecting the dispersion of the water repellent. After removal, the safety of the production environment is improved (the PM2.5 emission is reduced by more than 30%).

[0045] Metal particles (such as iron filings) may catalyze the cement hydration reaction, resulting in local rapid coagulation or generating expansion stress. After removal, the expansion stress can be reduced and the structural strength of the material can be improved.

[0046] Resin lumps (such as rosin condensates) are difficult to break during the mixing process, which can lead to uneven distribution of the water repellent locally. The resin-rich areas will hinder the penetration of the mildew preventive (such as borax) and become breeding points for mold. Therefore, it is possible to reduce the water absorption rate of the material, improve the waterproof property, and at the same time further enhance the penetration of the mildew preventive so as to improve the mildew resistance.

[0047] In this embodiment, further, the lye in the cedar sawdust is neutralized by soaking it in a 1% sodium hydroxide solution for 24 hours, with the temperature controlled at 60 ± 5 °C, and the pH value is monitored in real time to maintain the pH value between 11.5 - 12.0. When the pH value drops by more than 0.5, sodium hydroxide solution is replenished to neutralize the lignin in the cedar sawdust. The drying of the cedar sawdust is carried out by gradient drying. In the pre-drying stage, it is first dried under a hot air circulation at 80 °C for 1 hour, and then deep drying is carried out. In the deep drying, it is dried under vacuum at 50 °C until the moisture content ≤ 5%, and the weight is monitored every 30 minutes. The function of gradient drying is that the high-temperature hot air quickly evaporates the free water on the surface and in the large capillary pores of the cedar sawdust (removing about 60% of the moisture), avoiding the rapid vaporization of moisture during subsequent vacuum drying, which may cause the sawdust to crack. 80 °C can kill most mold spores (such as the lethal temperature of Aspergillus niger is 70 °C / 30 min), reducing the risk of biodegradation; the low temperature of 50 °C can slowly remove the bound water inside the cell wall, avoiding the thermal decomposition of lignin caused by high temperature (lignin starts to soften when the temperature > 60 °C). Weighing every 30 minutes ensures accurate control of the moisture content (error ≤ 0.3%). When the difference in weight between two consecutive weighings < 0.5%, the end point is determined to avoid fiber embrittlement caused by over-drying. Finally, the dried cedar sawdust is placed in a humidity-controlled box to balance for 24 hours. The constant humidity parameters of the humidity-controlled box are RH45% and temperature 25 °C. The 45% RH environment is close to the fiber saturation point (FSP) of wood, which can relieve the internal stress generated during the drying process (the drying cracks are reduced by 70%), thereby releasing the stress of the cedar sawdust.

[0048] In this embodiment, further, for the mildew prevention treatment of the cedar sawdust, it is soaked in a 0.5% borax solution. First, a 0.5% borax solution is compounded with 0.2% quaternary ammonium salt and then soaked. It is soaked at 60 °C for 2 hours, and vacuum is pumped for 10 minutes during the soaking. The borax solution can form a protective layer on the surface of the cedar sawdust, improving the flame retardancy of the material. The hydrophobic group of the quaternary ammonium salt can reduce the dissolution of borax in the water curing environment. After compounding, the mildew prevention spectrum is wider, and the risk of drug resistance of a single agent is avoided, enhancing the advantage of synergistic effect.

[0049] In this embodiment, further, the beeswax coating of the Chinese fir sawdust is achieved by heating and melting the beeswax and then evenly spraying it on the surface of the Chinese fir sawdust. The beeswax and rosin are melted together in a mass ratio of 4:1, and 5% nano-titanium dioxide and 1% fluorosilane are added. Then, it is evenly sprayed on the surface of the Chinese fir sawdust by means of high-voltage electrostatic spraying. Finally, it is dried, cooled, and shaped with cold air at 5°C. Selecting beeswax can simulate the natural honeycomb environment, thus promoting the bees to build nests, and it has higher mildew resistance, improving the adhesion between the coating and the Chinese fir sawdust (the pull-out strength is increased by 30%), preventing the wax layer from peeling off. Beeswax provides hydrophobicity, and rosin enhances the adhesiveness, making the coating have both waterproof and durability properties and improving the synergistic effect. It generates reactive oxygen species (ROS) under light, killing molds (such as Aspergillus niger) and bacteria (such as Escherichia coli), and the antibacterial rate > 95% (ISO 22196), thus delaying the biodegradation of Chinese fir sawdust in a humid environment. Fluorosilane significantly reduces water adsorption and improves the waterproof property.

[0050] In this embodiment, further, in step S2, portland cement, fly ash, and nano-silica are dry-mixed for 3 min in a ratio of 40%-50%:15%-20%:2%-3%. The dry-mixing treatment is carried out under nitrogen protection, the rotation speed of the mixer is controlled at 200 ± 50 rpm, and the temperature is controlled ≤ 40°C. Before dry-mixing, the fly ash is activated. The activation is carried out by drying at 105 ± 5°C for 2 h. The role of activating the fly ash is to avoid the premature hydration reaction between water and cement during dry-mixing, resulting in a decrease in fluidity, eliminating the interference of water on the dispersion of nano-silica, making it easier to adsorb nano-silica on the surface, forming a "core-shell" structure, and accelerating the pozzolanic reaction.

[0051] In this embodiment, further, in step S3, expanded perlite is added and stirred at medium speed for 2 min. The addition of expanded perlite is carried out in a gradient manner. First, half of the amount with a particle size of 1 - 3 mm is added and stirred for 1 min, and then the other half is added and stirred for 1 min. After the treatment in step S3, the Chinese fir sawdust pretreated in step S1 is added and stirred at low speed for 1 min. The amount of expanded perlite is between 20% - 25% of the total amount, and the amount of Chinese fir sawdust is between 1% - 2% of the total amount. The expanded perlite plays a role in improving heat insulation and fire protection.

[0052] In this embodiment, further, in step S5, polypropylene fibers are added and stirred for 2 min. The amount of polypropylene fibers is between 0.5% - 0.8% of the total amount. In step S6, a mixture of a water repellent and water is added. The amount of the water repellent is between 0.5% - 1% of the total amount. It is preheated to 50°C first, and then 0.1% defoamer is added and stirred at high speed for 5 min. Stirring the polypropylene fibers can optimize the fiber orientation. The appropriate shear force makes the fibers tend to be randomly distributed in three dimensions in the slurry, enhancing the isotropic strengthening effect. The synergy of the water repellent and the defoamer improves the waterproof property, and the defoamer avoids the formation of defects by bubbles in the material and reduces the surface tension.

[0053] Finally, in step S7, after adding calcium formate coagulant after step S6 and injecting it into the mold, vibrate for 60 s first and then keep it static for 24 h. In step S8, after demolding, perform steam curing, cure at a temperature of 55 °C for 12 h, and naturally dry for 7 days. Spray a 5% potassium carbonate solution once a day to improve the structural strength of the material and make it more durable.

[0054] In this embodiment, 200 kg of portland cement, 80 kg of fly ash, 100 kg of expanded perlite, 2 kg of polypropylene fiber, 5 kg of Chinese fir sawdust, 10 kg of nano-silica, 3 kg of water repellent, 1 kg of beeswax, and 95 kg of water are selected for preparation. The density of the prepared material product is 760 kg / m 3 , the compressive strength is 4.8 MPa, and the mold-proof grade is 0 (no mildew).

[0055] Example 2

[0056] In this embodiment, the preparation steps of Example 1 are adopted. 220 kg of portland cement, 70 kg of fly ash, 90 kg of expanded perlite, 2.5 kg of polypropylene fiber, 6 kg of Chinese fir sawdust, 12 kg of nano-silica, 4 kg of water repellent, 1.5 kg of beeswax, and 100 kg of water are selected for preparation. The density of the prepared material product is 770 kg / m 3 , the compressive strength is 5.0 MPa, and the mold-proof grade is 0.

[0057] The above embodiments are only the preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention fall within the scope of protection required by the present invention.

Claims

1. A preparation method of materials for making beehives, characterized in that, It is prepared by including the following steps: S1: Pretreatment of Chinese fir sawdust; S2: Mix silicate cement, fly ash and nano-silica; S3: Add expanded perlite and stir after step S2; S4: Add the Chinese fir sawdust pretreated in step S1 and stir after step S3; S5: Add polypropylene fiber and stir after step S4; S6: Add a mixture of water repellent and water and stir after step S5; S7: Pour into a mold and let it stand for setting; S8: Demold and cure, and naturally dry to obtain the material for making beehives.

2. The preparation method of a bee box manufacturing material according to claim 1, characterized in that In step S1, the pretreatment of Chinese fir sawdust is carried out in sequence according to the processes of screening, alkali solution neutralization, drying, mildew prevention treatment and beeswax wrapping.

3. The preparation method of a bee box manufacturing material according to claim 2, characterized in that, For the screening of Chinese fir sawdust, the sawdust with a particle size of 2 - 3 mm is screened out and impurities are removed. The screening of Chinese fir sawdust is carried out through multi-stage screening. First, a vibrating screen with a 4 mm aperture is used to remove large particles, then a 2 mm standard screen is used for screening, and the sawdust with a particle size of 2 - 3 mm is retained. Airflow separation is used to remove dust in the Chinese fir sawdust, and a magnetic separator is used to remove metal impurities in the Chinese fir sawdust. An optoelectronic sorter identifies and removes resin lumps.

4. The preparation method of a bee box manufacturing material according to claim 3, characterized in that, The alkali solution neutralization of Chinese fir sawdust is carried out by soaking in a 1% sodium hydroxide solution for 24 h, controlling the temperature at 60 ± 5 °C, and monitoring the pH value in real time to maintain the pH value between 11.5 - 12.

0. When the pH value drops by more than 0.5, sodium hydroxide solution is supplemented. The drying of Chinese fir sawdust is carried out by gradient drying. In the pre-drying stage, it is first dried under hot air circulation at 80 °C for 1 h, and then deep drying is carried out. Under deep drying, it is dried under vacuum at 50 °C until the moisture content ≤ 5%, and the weight is monitored every 30 min. Finally, the dried Chinese fir sawdust is placed in a constant humidity box to balance for 24 h. The constant humidity parameters of the constant humidity box are RH45% and temperature 25 °C.

5. The preparation method of a bee box manufacturing material according to claim 4, characterized in that The mildew prevention treatment of Chinese fir sawdust is carried out by soaking in a 0.5% borax solution. First, a 0.5% borax solution and 0.2% quaternary ammonium salt are compounded and soaked, and soaked at 60 °C for 2 h, and vacuum is pumped for 10 min during soaking.

6. The preparation method of a bee box manufacturing material according to claim 5, characterized in that, The beeswax wrapping of Chinese fir sawdust is carried out by heating and melting beeswax and evenly spraying it on the surface of Chinese fir sawdust. Beeswax and rosin are melted together in a mass ratio of 4:1, and 5% nano-titanium dioxide and 1% fluorosilane are added, and it is evenly sprayed on the surface of Chinese fir sawdust by means of high-voltage electrostatic spraying. Finally, it is dried and cooled with cold air at 5 °C and shaped.

7. The preparation method of a bee box manufacturing material according to claim 1, characterized in that In step S2, silicate cement, fly ash and nano-silica are dry-mixed for 3 min in a ratio of 40% - 50%:15% - 20%:2% - 3%, and dry-mixed under nitrogen protection. The rotation speed of the mixer is controlled at 200 ± 50 rpm, and the temperature is controlled ≤ 40 °C. Before dry-mixing, fly ash is activated by drying at 105 ± 5 °C for 2 h.

8. The preparation method of a bee box manufacturing material according to claim 1, characterized in that, In step S3, expanded perlite is added and stirred at medium speed for 2 min. The addition of expanded perlite is carried out in a gradient manner. First, half of the amount with a particle size of 1 - 3 mm is added and stirred for 1 min, and then the other half is added and stirred for 1 min. After the treatment in step S3, the Chinese fir sawdust pretreated in step S1 is added and stirred at low speed for 1 min.

9. The preparation method of a bee box manufacturing material according to claim 1, characterized in that, In step S5, polypropylene fibers are added and stirred for 2 minutes. In step S6, a mixed solution of a water repellent and water is added. First, it is preheated to 50 °C, and then 0.1% defoamer is added and stirred at high speed for 5 minutes.

10. The preparation method of a bee box manufacturing material according to claim 1, characterized in that, In step S7, after adding a calcium formate coagulant after step S6, it is injected into a mold. First, it is vibrated for 60 seconds and then left standing for 24 hours. In step S8, after demolding, steam curing is carried out. It is cured at a temperature of 55 °C for 12 hours and naturally dried for 7 days. A 5% potassium carbonate solution is sprayed once a day.

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