A kind of national defense civil defense door filling material, national defense civil defense door and preparation method of national defense civil defense door

Abstract

The application discloses a kind of national defense civil defense door fillers, national defense civil defense door and the preparation method of national defense civil defense door, the national defense civil defense door includes the following weight parts of components: Portland cement 30-40 parts, modified porous particles 20-30 parts, modified rubber particles 2-5 parts, silicon powder 5-10 parts, quartz sand 5-10 parts, quartz powder 5-10 parts, water reducing agent 0.6-0.9 parts, fiber mesh 1-10 parts and water 6-8 parts.The national defense civil defense door has the advantages of light weight, high strength, etc., can effectively solve the problems existing in the prior art national defense civil defense door.

Description

Technical Field

[0001] This invention belongs to the field of civil defense door technology, specifically relating to a filling material for a national defense civil defense door, a national defense civil defense door, and a method for preparing a national defense civil defense door. Background Technology

[0002] Civil defense doors are the entrances and exits of civil defense projects. They are used by the government to mobilize and organize the masses to take measures for air raid defense, disaster relief, and rescue operations, and to prevent and mitigate the harm of disasters. Civil defense doors belong to civil defense protection equipment. National defense doors are similar to civil defense doors, but differ in specific thickness and structure; both are mainly composed of reinforced concrete composite structures and steel structures, providing a certain degree of shock wave protection and effectively ensuring the safety and stability of the interior of civil defense spaces.

[0003] Currently, filling steel structures with concrete, leveraging concrete's high impact resistance and durability to fabricate air-raid shelter doors, can improve their safety performance. However, the weight of concrete makes these doors very bulky, hindering transportation, installation, and subsequent use. Therefore, reducing the weight of air-raid shelter doors while maintaining their impact resistance, compressive strength, and other mechanical properties is of paramount importance. Summary of the Invention

[0004] In view of the above-mentioned shortcomings in the prior art, the present invention provides a filling material for a national defense civil defense door, a national defense civil defense door, and a method for preparing the national defense civil defense door. The national defense civil defense door has the advantages of being lightweight and having high strength, and can effectively solve the problems existing in the current national defense civil defense door.

[0005] To achieve the above objectives, the technical solution adopted by the present invention to solve its technical problem is as follows:

[0006] A type of filler for civil defense doors comprises the following components in parts by weight: 30-40 parts silicate cement, 20-30 parts modified porous particles, 2-5 parts modified rubber particles, 5-10 parts silica powder, 5-10 parts quartz sand, 5-10 parts quartz powder, 0.6-0.9 parts water-reducing agent, 1-10 parts fiber mesh, and 6-8 parts water.

[0007] Furthermore, the modified porous particles are prepared by the following method: polycarbonate is heated to melt, porous particles are added to it, stirred and mixed, then cooled and solidified under stirring conditions and crushed into particles, then a coupling agent is added to it, stirred and mixed to obtain the modified porous particles.

[0008] Furthermore, porous particles include one of zeolite, ceramsite, and volcanic rock.

[0009] Furthermore, the porous particles have a particle size of 1-3 mm.

[0010] Furthermore, the mass ratio of polycarbonate, porous particles, and coupling agent is 1:2-3:0.5-1.

[0011] Furthermore, the modified rubber granules are prepared by the following method: the rubber granules are immersed in a sodium hydroxide solution, taken out, rinsed until neutral and dried, and then a coupling agent is added to the rubber granules, dried, and the modified rubber granules are obtained.

[0012] Furthermore, the rubber granules are made from the crushing of waste tires, with a particle size of 0.5-2mm and a mass ratio of rubber granules to coupling agent of 2-6:1.

[0013] Furthermore, the silicate cement is 52.5 silicate cement.

[0014] Furthermore, the specific surface area of ​​the silicon powder is greater than 19000 m². 2 / kg.

[0015] Furthermore, the particle size of the quartz sand is 0.1-0.3 mm.

[0016] Furthermore, the fiber mesh includes steel fiber mesh or organic fiber mesh, wherein the organic fiber mesh is basalt fiber mesh, carbon fiber mesh or glass fiber mesh; the diameter of the fiber filaments in the fiber mesh is 0.02-0.5mm, the pore size of the fiber mesh is less than or equal to 30 mesh, and the tensile strength of the fiber mesh is greater than or equal to 500Mpa.

[0017] A type of national defense civil defense door is made by filling with the above-mentioned filler material.

[0018] Furthermore, the preparation method of the aforementioned national defense civil defense door includes the following steps:

[0019] (1) Silicate cement, modified porous particles, modified rubber particles, silica powder, quartz sand and quartz powder are mixed evenly to obtain a mixture; water-reducing agent and water are added to the mixture and mixed evenly to obtain a slurry;

[0020] (2) The slurry and fiber mesh are alternately laid in the mold. During this process, air bubbles in the slurry are expelled while pouring, and then the mixture is allowed to stand and harden.

[0021] (3) The hardened and demolded board is steam cured, and then the board is naturally cured by sprinkling water to obtain the product.

[0022] The beneficial effects of this invention are as follows:

[0023] 1. The filler of this invention contains modified porous particles. The core of the modified porous particles has a porous structure, which has the functions of light weight, sound absorption, and heat insulation, thereby reducing the weight of the defense air defense door and improving its sound insulation and heat insulation effects. The surface of the porous particles is coated with polycarbonate. Polycarbonate is a thermosetting material with advantages such as high hardness, strong impact resistance, and hydrophobicity. This gives the coated porous particles strong hardness and impact resistance, allowing them to be used as hard aggregate, reducing the amount of sand and gravel hard aggregate. This improves the impact resistance of the defense air defense door while reducing its weight. At the same time, the polycarbonate-coated porous particles have a hydrophobic effect, which can increase the strength of the subsequent filler with less water, thereby improving the mechanical properties of the defense air defense door. A coupling agent is added during the preparation of the modified porous particles. The coupling agent can act as a connecting bridge to increase the connection strength between the porous particles and polycarbonate. At the same time, the silane coupling agent can also be used to promote the connection strength between the porous modified particles and cement, thereby increasing the strength of the filler.

[0024] 2. The filler of the present invention has multiple layers of fiber mesh laid flat. The fiber mesh is used as a tensioning and connecting component to gather and fix the filler, making the interior of the filler dense and further improving the strength of the filler material. At the same time, it can avoid the use of steel bars and also achieve the purpose of reducing the weight of the air defense door.

[0025] 3. Modified rubber particles are added to the filler of this invention. After being soaked in alkali, impurities on the surface of the rubber particles are removed, increasing their surface roughness, which improves their hydrophilicity and dispersion uniformity. A coupling agent is added to increase the bonding strength between the rubber particles and cement. The addition of rubber particles can improve the toughness of the filler. When the defense door is subjected to shock waves, the elasticity of the rubber particles can provide a certain buffering effect, avoiding the problem of brittle fracture of the door without the addition of steel reinforcement. However, the amount of modified rubber particles added should be moderate. If the amount added is too large, it will easily reduce the strength of the defense door; if the amount added is too small, it will not play a buffering role. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments.

[0027] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0028] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0029] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0030] Example 1

[0031] A type of filler for civil defense doors comprises the following components in parts by weight: 30 parts of 52.5 silicate cement, 20 parts of modified zeolite particles, 2 parts of modified rubber particles, and a specific surface area of ​​20,000 m². 2 10 parts / kg silicon powder, 10 parts quartz sand with a particle size of 0.1mm, and a specific surface area of ​​10000m² 2 The mixture consists of 10 parts per kg of quartz powder, 0.6 parts of polycarboxylate superplasticizer with a water reduction rate of 36%, 10 parts of carbon fiber mesh, and 8 parts of water; wherein the carbon fiber mesh has a wire diameter of 0.02 mm and a mesh size of 40 mesh.

[0032] The modified porous particles are prepared by the following method: polycarbonate is heated to melt, zeolite particles with a particle size of 1 mm are added to it, stirred and mixed, then cooled and solidified under stirring conditions and crushed into particles, then silane coupling agent is added to it, stirred and mixed to obtain modified zeolite particles, wherein the mass ratio of polycarbonate, zeolite particles and silane coupling agent is 1:3:0.5;

[0033] Modified rubber granules were prepared by the following method: rubber granules with a particle size of 1 mm were soaked in a 10% sodium hydroxide solution for 2 hours, then rinsed until neutral and dried. Then, a silane coupling agent was added to the rubber granules and dried to obtain the product. The mass ratio of rubber granules to silane coupling agent was 2:1.

[0034] A type of national defense civil defense door, made using the above-mentioned filler material, is prepared by the following method:

[0035] (1) Dry mix silicate cement, modified zeolite particles, modified rubber particles, silica powder, quartz sand and quartz powder for 5 minutes, mix well to obtain a mixture; add polycarboxylate superplasticizer and water to the mixture, stir for 5 minutes, mix well to obtain a slurry;

[0036] (2) Pour a layer of slurry into the mold, then lay a layer of carbon fiber mesh on the surface of the slurry, then continue to pour a layer of slurry on the surface of the carbon fiber mesh, and then continue to lay a layer of carbon fiber mesh on the surface of the slurry. Repeat the above operation, alternately lay the slurry and carbon fiber mesh in the mold, and continuously vibrate to remove air bubbles in the slurry, and then let it stand to harden for 30 hours.

[0037] (3) The hardened and demolded board is steam cured. During this period, the temperature is increased to 90°C at a rate of 15°C / min and kept constant for 48 hours. Then the temperature is reduced to room temperature at a rate of 15°C / min. The board is then water-cured. Specifically, water is sprayed onto the surface of the board and wrapped with a water-retaining film. The curing continues for 8 days to obtain the final product.

[0038] Example 2

[0039] A type of filler for civil defense doors comprises the following components in parts by weight: 40 parts of 52.5 silicate cement, 30 parts of modified ceramic particles, 2 parts of modified rubber particles, and a specific surface area of ​​30,000 m². 2 5 parts / kg silica powder, 5 parts quartz sand with a particle size of 0.3mm, and a specific surface area of ​​10000m² 2 The mixture consists of 7 parts per kg of quartz powder, 0.9 parts of polycarboxylate superplasticizer with a water reduction rate of 38%, 2 parts of basalt fiber mesh, and 6 parts of water; wherein the basalt fiber mesh has a wire diameter of 0.5 mm and the carbon fiber mesh has a pore size of 30 mesh.

[0040] The modified ceramic particles are prepared by the following method: polycarbonate is heated to melt, ceramic particles with a particle size of 3 mm are added to it, stirred and mixed, then cooled and solidified under stirring conditions and crushed into particles, then silane coupling agent is added to it, stirred and mixed to obtain modified ceramic particles, wherein the mass ratio of polycarbonate, ceramic particles and silane coupling agent is 1:2:0.5;

[0041] Modified rubber granules were prepared by the following method: rubber granules with a particle size of 2 mm were soaked in a 10% sodium hydroxide solution for 2 hours, then rinsed until neutral and dried. Then, a silane coupling agent was added to the rubber granules, and the mixture was dried to obtain the product. The mass ratio of rubber granules to silane coupling agent was 6:1.

[0042] A type of national defense civil defense door, made using the above-mentioned filler material, is prepared by the following method:

[0043] (1) Dry mix silicate cement, modified ceramic particles, modified rubber particles, silica powder, quartz sand and quartz powder for 5 minutes, mix well to obtain a mixture; add polycarboxylate superplasticizer and water to the mixture, stir for 5 minutes, mix well to obtain a slurry;

[0044] (2) Pour a layer of slurry into the mold, then lay a layer of fiber mesh on the surface of the slurry, then continue to pour a layer of slurry on the surface of the fiber mesh, and then continue to lay a layer of fiber mesh on the surface of the slurry. Repeat the above operation, alternately lay the slurry and fiber mesh in the mold, and continuously vibrate to remove air bubbles in the slurry, and then let it stand to harden for 24 hours.

[0045] (3) The hardened and demolded board is steam cured. During this period, the temperature is increased to 90°C at a rate of 15°C / min and kept constant for 48 hours. Then the temperature is reduced to room temperature at a rate of 15°C / min. The board is then water-cured. Specifically, water is sprayed onto the surface of the board and wrapped with a water-retaining film. The curing continues for 8 days to obtain the final product.

[0046] Example 3

[0047] A type of filler for civil defense doors comprises the following components in parts by weight: 35 parts of 52.5 silicate cement, 30 parts of modified volcanic rock particles, 5 parts of modified rubber particles, and a specific surface area of ​​20,000 m². 2 The mixture consists of 7 parts / kg silica powder, 7 parts quartz sand with a particle size of 0.2mm, 8 parts quartz powder, 0.8 parts polycarboxylate superplasticizer with a water reduction rate of 37%, 8 parts steel fiber mesh, and 8 parts water; wherein the steel fiber mesh has a wire diameter of 0.3mm and a mesh size of 40 mesh.

[0048] The modified volcanic rock particles are prepared by the following method: polycarbonate is heated to melt, volcanic rock particles with a particle size of 2 mm are added to it, stirred and mixed evenly, then cooled and solidified under stirring conditions and crushed into particles, then a silane coupling agent is added to it, stirred and mixed evenly to obtain modified volcanic rock particles, wherein the mass ratio of polycarbonate, volcanic rock particles and coupling agent is 1:3:1;

[0049] Modified rubber granules were prepared by the following method: rubber granules with a particle size of 1 mm were soaked in a 10% sodium hydroxide solution for 2 hours, then rinsed until neutral and dried. A coupling agent was added to the rubber granules, and the mixture was dried to obtain the product. The mass ratio of rubber granules to coupling agent was 5:1.

[0050] A type of national defense civil defense door, made using the above-mentioned filler material, is prepared by the following method:

[0051] (1) Dry mix silicate cement, modified volcanic rock particles, modified rubber particles, silica powder, quartz sand and quartz powder for 5 minutes, mix well to obtain a mixture; add polycarboxylate superplasticizer and water to the mixture, stir for 5 minutes, mix well to obtain a slurry;

[0052] (2) Pour a layer of slurry into the mold, then lay a layer of fiber mesh on the surface of the slurry, then continue to pour a layer of slurry on the surface of the fiber mesh, and then continue to lay a layer of fiber mesh on the surface of the slurry. Repeat the above operation, alternately lay the slurry and fiber mesh in the mold, and continuously vibrate to remove air bubbles in the slurry, and then let it stand to harden for 28 hours.

[0053] (3) The hardened and demolded board is steam cured. During this period, the temperature is increased to 90°C at a rate of 15°C / min and kept constant for 48 hours. Then the temperature is reduced to room temperature at a rate of 15°C / min. The board is then water-cured. Specifically, water is sprayed onto the surface of the board and wrapped with a water-retaining film. The curing continues for 8 days to obtain the final product.

[0054] Comparative Example 1

[0055] A type of filler for civil defense doors comprises the following components in parts by weight: 65 parts of 52.5 silicate cement, 5 parts of modified rubber particles, and a specific surface area of ​​20,000 m². 2 The mixture consists of 7 parts / kg silica powder, 7 parts quartz sand with a particle size of 0.2mm, 8 parts quartz powder, 0.8 parts polycarboxylate superplasticizer with a water reduction rate of 37%, 8 parts steel fiber mesh, and 15 parts water; wherein the steel fiber mesh has a wire diameter of 0.3mm and a mesh size of 40 mesh.

[0056] Modified rubber granules were prepared by the following method: rubber granules with a particle size of 1 mm were soaked in a 10% sodium hydroxide solution for 2 hours, then rinsed until neutral and dried. A coupling agent was added to the rubber granules, and the mixture was dried to obtain the product. The mass ratio of rubber granules to coupling agent was 5:1.

[0057] A type of national defense civil defense door, made using the above-mentioned filler material, is prepared by the following method:

[0058] (1) Dry mix silicate cement, modified rubber particles, silica powder, quartz sand and quartz powder for 5 minutes, mix well to obtain a mixture; add polycarboxylate superplasticizer and water to the mixture, stir for 5 minutes, mix well to obtain a slurry;

[0059] (2) Pour a layer of slurry into the mold, then lay a layer of fiber mesh on the surface of the slurry, then continue to pour a layer of slurry on the surface of the fiber mesh, and then continue to lay a layer of fiber mesh on the surface of the slurry. Repeat the above operation, alternately lay the slurry and fiber mesh in the mold, and continuously vibrate to remove air bubbles in the slurry, and then let it stand to harden for 28 hours.

[0060] (3) The hardened and demolded board is steam cured. During this period, the temperature is increased to 90°C at a rate of 15°C / min and kept constant for 48 hours. Then the temperature is reduced to room temperature at a rate of 15°C / min. The board is then water-cured. Specifically, water is sprayed onto the surface of the board and wrapped with a water-retaining film. The curing continues for 8 days to obtain the final product.

[0061] Comparative Example 2

[0062] A type of filler for civil defense doors comprises the following components in parts by weight: 35 parts of 52.5 silicate cement, 30 parts of modified volcanic rock particles, and a specific surface area of ​​20,000 m². 2 The mixture consists of 7 parts / kg silica powder, 7 parts quartz sand with a particle size of 0.2mm, 8 parts quartz powder, 0.8 parts polycarboxylate superplasticizer with a water reduction rate of 37%, 8 parts steel fiber mesh, and 8 parts water; wherein the steel fiber mesh has a wire diameter of 0.3mm and a mesh size of 40 mesh.

[0063] The modified volcanic rock particles are prepared by the following method: polycarbonate is heated to melt, volcanic rock particles with a particle size of 2 mm are added to it, stirred and mixed evenly, then cooled and solidified under stirring conditions and crushed into particles, then a silane coupling agent is added to it, stirred and mixed evenly to obtain modified volcanic rock particles, wherein the mass ratio of polycarbonate, volcanic rock particles and coupling agent is 1:3:1;

[0064] A type of national defense civil defense door, made using the above-mentioned filler material, is prepared by the following method:

[0065] (1) Dry mix silicate cement, modified volcanic rock particles, silica powder, quartz sand and quartz powder for 5 minutes, mix well to obtain a mixture; add polycarboxylate superplasticizer and water to the mixture, stir for 5 minutes, mix well to obtain a slurry;

[0066] (2) Pour a layer of slurry into the mold, then lay a layer of fiber mesh on the surface of the slurry, then continue to pour a layer of slurry on the surface of the fiber mesh, and then continue to lay a layer of fiber mesh on the surface of the slurry. Repeat the above operation, alternately lay the slurry and fiber mesh in the mold, and continuously vibrate to remove air bubbles in the slurry, and then let it stand to harden for 28 hours.

[0067] (3) The hardened and demolded board is steam cured. During this period, the temperature is increased to 90°C at a rate of 15°C / min and kept constant for 48 hours. Then the temperature is reduced to room temperature at a rate of 15°C / min. The board is then water-cured. Specifically, water is sprayed onto the surface of the board and wrapped with a water-retaining film. The curing continues for 8 days to obtain the final product.

[0068] Comparative Example 3

[0069] A type of filler for civil defense doors comprises the following components in parts by weight: 35 parts of 52.5 silicate cement, 30 parts of modified volcanic rock particles, 5 parts of modified rubber particles, and a specific surface area of ​​20,000 m². 2 7 parts of silica powder per kg, 7 parts of quartz sand with a particle size of 0.2 mm, 8 parts of quartz powder, 0.8 parts of polycarboxylate superplasticizer with a water reduction rate of 37%, 8 parts of steel fiber with a length of 5 cm, and 8 parts of water.

[0070] The modified volcanic rock particles are prepared by the following method: polycarbonate is heated to melt, volcanic rock particles with a particle size of 2 mm are added to it, stirred and mixed evenly, then cooled and solidified under stirring conditions and crushed into particles, then a silane coupling agent is added to it, stirred and mixed evenly to obtain modified volcanic rock particles, wherein the mass ratio of polycarbonate, volcanic rock particles and coupling agent is 1:3:1;

[0071] Modified rubber granules were prepared by the following method: rubber granules with a particle size of 1 mm were soaked in a 10% sodium hydroxide solution for 2 hours, then rinsed until neutral and dried. A coupling agent was added to the rubber granules, and the mixture was dried to obtain the product. The mass ratio of rubber granules to coupling agent was 5:1.

[0072] A type of national defense civil defense door, made using the above-mentioned filler material, is prepared by the following method:

[0073] (1) Dry mix silicate cement, modified volcanic rock particles, modified rubber particles, silica powder, quartz sand, quartz powder and steel fiber for 5 minutes, mix well to obtain a mixture; add polycarboxylate superplasticizer and water to the mixture, stir for 5 minutes, mix well to obtain a slurry;

[0074] (2) Vibrate continuously while pouring the slurry into the mold to remove air bubbles, and then let it stand to harden for 28 hours;

[0075] (3) The hardened and demolded board is steam cured. During this period, the temperature is increased to 90°C at a rate of 15°C / min and kept constant for 48 hours. Then the temperature is reduced to room temperature at a rate of 15°C / min. The board is then water-cured. Specifically, water is sprayed onto the surface of the board and wrapped with a water-retaining film. The curing continues for 8 days to obtain the final product.

[0076] Test case

[0077] The difference between defense doors and civil defense doors lies in the thickness of the filling material. Taking the preparation methods of Chinese civil defense doors in Examples 1-3 and Comparative Examples 1-4 as examples, the mechanical properties of the test blocks were tested. The test standard refers to GB / T50081. The specific test results are shown in Table 1.

[0078] Table 1: Mechanical properties of the test blocks

[0079] Example 1 165 16.5 30.8 1845 Example 2 163 16.4 29.4 1879 Example 3 169 16.2 29.1 1861 Comparative Example 1 162 16.2 24.3 2432 Comparative Example 2 139 6.9 9.9 1944 Comparative Example 3 141 7.4 11.3 1855

[0080] As can be seen from the data in the table above, the compressive, tensile, and load-bearing strengths of the air-raid shelter doors prepared using the methods in Examples 1-3 are all higher than those of the air-raid shelter doors in Comparative Examples 1-4, proving that the air-raid shelter doors prepared using the formula and method in this application have better mechanical properties and are lighter in weight.

[0081] The air-raid shelter door in Comparative Example 1 was compared with the air-raid shelter door in Example 3. The modified volcanic rock particles were removed and replaced with an equal amount of cement. In this case, more water was needed to be added during mixing to form a slurry with similar fluidity, which ultimately led to an increase in the weight of the air-raid shelter door. It is speculated that the main reason is that the use of a large amount of cement increased the density of the air-raid shelter door, resulting in an increase in the weight of the air-raid shelter door.

[0082] Comparing the air-raid shelter door in Comparative Example 2 with the air-raid shelter door in Example 3, the use of modified rubber particles was eliminated. It can be seen that the mechanical properties of the air-raid shelter door deteriorated. It is speculated that the main reason is the lack of the buffering effect of the rubber particles, which led to the deterioration of its mechanical properties.

[0083] Comparing the air-raid shelter door in Comparative Example 3 with the air-raid shelter door in Example 3, replacing the fiber mesh with short fibers and dispersing the short fibers evenly inside the filler, it can be seen that the mechanical properties of the air-raid shelter door deteriorate. It is speculated that the main reason is that the multi-layer fiber mesh inside the filler forms a traction network structure, which improves the mechanical properties of the air-raid shelter door, while using short fibers cannot achieve a similar effect.

Claims

1. A method for preparing a national defense civil defense door, characterized in that, Includes the following steps: (1) Silicate cement, modified porous particles, modified rubber particles, silica powder, quartz sand and quartz powder are mixed evenly to obtain a mixture; water-reducing agent and water are added to the mixture and mixed evenly to obtain a slurry; (2) Pour a layer of slurry into the mold, then lay a layer of fiber mesh on the surface of the slurry, then pour another layer of slurry on the surface of the fiber mesh, and then lay another layer of fiber mesh on the surface of the slurry. Repeat the above operation, alternately laying the slurry and fiber mesh in the mold. During this period, vibrate continuously to remove air bubbles in the slurry, and then let it stand to harden. (3) The hardened and demolded board is steam cured. During this period, the temperature is increased to 90°C at a rate of 15°C / min and kept constant for 48 hours. Then the temperature is reduced to room temperature at a rate of 15°C / min. The board is then water-cured. Specifically, water is sprayed onto the surface of the board and wrapped with a water-retaining film. The curing is continued for 8 days to obtain the board. The filler used to prepare the national defense civil defense door is composed of the following components in parts by weight: 30-40 parts silicate cement, 20-30 parts modified porous particles, 2-5 parts modified rubber particles, 5-10 parts silica powder, 5-10 parts quartz sand, 5-10 parts quartz powder, 0.6-0.9 parts water-reducing agent, 1-10 parts fiber mesh, and 6-8 parts water. The modified porous particles are prepared by the following method: polycarbonate is heated to a melt, porous particles are added to it, stirred and mixed, then cooled and solidified under stirring conditions and crushed into granules, then a coupling agent is added to it, stirred and mixed, and dried to obtain modified porous particles; the mass ratio of polycarbonate, porous particles and coupling agent added to the porous particles is 1:2-3:0.5-1; the porous particles include one of zeolite, ceramsite and volcanic rock; The fiber mesh includes steel fiber mesh, basalt fiber mesh, carbon fiber mesh, or glass fiber mesh; the diameter of the fibers in the fiber mesh is 0.02-0.5 mm, and the mesh aperture is less than or equal to 30 mesh. The modified rubber particles are prepared by the following method: the rubber particles are soaked in sodium hydroxide solution, taken out, rinsed until neutral and dried, then a coupling agent is added to the rubber particles, and dried to obtain the product; the mass ratio of the rubber particles to the coupling agent added to the rubber particles is 2-6:1.