Cement-based electromagnetic wave absorbing canvas tent

Abstract

The application discloses a cement-based electromagnetic wave absorbing canvas tent, which comprises a gas bag, a plurality of cement-based electromagnetic wave absorbing canvases arranged on the outer surface of the gas bag, U-shaped nails used for connecting the cement-based electromagnetic wave absorbing canvases, an electromagnetic shielding door used for entry and exit, and an electromagnetic anti-seepage layer arranged on the outer surface of the cement-based electromagnetic wave absorbing canvas; the cement-based electromagnetic wave absorbing canvas comprises a three-dimensional framework structure of a steel fiber spiral coil with a wave absorbing function, a carbon fiber spiral coil with a wave absorbing function, a top layer and a dense bottom layer; the three-dimensional framework is filled with a cement-based material containing an electromagnetic wave absorbing component, and a dense surface layer is further arranged on the top layer to obtain the cement-based electromagnetic wave absorbing canvas; a plurality of cement-based electromagnetic wave absorbing canvases are connected together through the U-shaped nails to form a closed cloth bag, and the gas bag is used as the inner container of the cloth bag and does not need to be connected with the canvas; and the tent can quickly construct an electromagnetic wave absorbing structure and meet the rapid electromagnetic stealth requirements of personnel, equipment and structures.

Description

Technical Field

[0001] This invention relates to the field of concrete canvas tent technology, specifically a cement-based electromagnetic wave-absorbing canvas tent. Background Technology

[0002] With rapid technological advancements and ever-increasing global information levels, various methods of espionage are emerging, posing a severe challenge to information security. The construction of modern militaries is highly information-based, thus requiring sufficient attention to electromagnetic protection. Conventional emergency tents cannot withstand the impact of major natural disasters, provide electromagnetic protection, or withstand a certain degree of military damage. Cement-based electromagnetic absorbing canvas tents, however, can quickly provide soldiers with excellent electromagnetic protection and a certain degree of safety during wartime and military operations, serving as temporary shelters to avoid being targeted by the enemy and minimize casualties.

[0003] Previous research on concrete canvas primarily employed fast-hardening, early-strength magnesium phosphate cement-based absorbing agents to achieve electromagnetic shielding. However, this type of concrete canvas is difficult to form a completely sealed electromagnetic environment, and its absorption frequency range is limited, posing certain safety hazards. In military environments, its low strength makes it vulnerable to external physical attacks. Furthermore, because magnesium phosphate cement-based electromagnetic absorbing concrete canvas is mainly used for electromagnetic shielding within buildings, its impermeability is limited, making it susceptible to damage from rain, snow, and other natural disasters.

[0004] Previous research on concrete tents mainly focused on forming an integral structure with steel structures, which made them difficult to construct quickly to cope with complex military environments and inconvenient to use. They were mainly used for rain protection, sunshade, heat insulation, and ventilation, but did not provide good military defense. In addition, they usually did not have electromagnetic shielding effects, making it difficult to form a certain electromagnetic protection function. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned technical problems and provide a cement-based electromagnetic wave-absorbing canvas tent, a magnesium phosphate cement-based tent with electromagnetic wave absorption function and a polyurethane-based concrete canvas tent with waterproof function.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A cement-based electromagnetic wave-absorbing canvas tent, the tent comprising an airbag 3, several pieces of cement-based electromagnetic wave-absorbing canvas 1 laid on the outer surface of the airbag, U-shaped nails 2 for connecting different pieces of cement-based electromagnetic wave-absorbing canvas, an electromagnetic shielding door 4 for entry and exit, and an electromagnetic anti-seepage layer 11 disposed on the outer surface of the cement-based electromagnetic wave-absorbing canvas.

[0008] The cement-based electromagnetic wave-absorbing canvas includes a top layer 12, a hollow layer 13, and a densely woven bottom layer 14 arranged from top to bottom. Between the top layer and the densely woven bottom layer, there are intermediate spacer yarns I and intermediate yarns II. Intermediate yarn I is made of steel fiber spiral coils with wave-absorbing function, and spacer yarn II is made of carbon fiber spiral coils with wave-absorbing function. The two intermediate yarns, together with the top layer and the densely woven bottom layer, constitute the three-dimensional skeleton structure of the cement-based electromagnetic wave-absorbing canvas. Cement-based material containing electromagnetic wave-absorbing components is poured from the top layer into the hollow layer, vibrated and filled into the entire three-dimensional skeleton. A densely woven surface layer is then laid on the outside of the top layer to obtain the cement-based electromagnetic wave-absorbing canvas.

[0009] Multiple pieces of cement-based electromagnetic absorbing canvas are connected together with U-shaped nails to form a closed bag. The air bladder serves as the inner lining of the bag and does not need to be connected to the canvas. An electromagnetic shielding door is installed at the bag opening to form a closed electromagnetic shielding space with the canvas bag. After the air bladder is inflated, it can form a tent shape. During the inflation process, the bag can bulge with the air bladder, and the cement-based electromagnetic absorbing canvas itself will not crack. After inflation, water is sprayed on the outer surface of the canvas tent and cured at room temperature to form stable strength. Finally, a waterproof coating containing electromagnetic absorbing components is applied to the densely woven surface of the cement-based electromagnetic absorbing canvas to form an electromagnetic anti-seepage layer, thus obtaining the cement-based electromagnetic absorbing canvas tent.

[0010] Furthermore, the electromagnetic anti-seepage layer 11 has a thickness of 8-12mm, the overall thickness of the cement-based electromagnetic absorbing canvas is 40-60mm, and the total height and number of turns of the carbon fiber spiral coil and the steel fiber spiral coil can be adapted to the thickness of the canvas, so that the canvas has a certain elasticity and toughness.

[0011] The cement-based material containing an electromagnetic absorbing component includes a cement-based component and an electromagnetic absorbing component. The electromagnetic absorbing component in the cement-based material is at least one of the following: micron-sized titanium dioxide particles, or absorbing ceramic particles made from micron-sized titanium dioxide, carbon powder, nano-ferric oxide, graphene oxide, and multi-walled carbon nanotubes. The cement-based component includes phosphate, high-iron fly ash, borax, and MgO. The electromagnetic absorbing component includes at least absorbing ceramic particles made from micron-sized titanium dioxide and nano-ferric oxide, and also includes carbon powder or graphene oxide, wherein the mass ratio of absorbing ceramic particles to nano-ferric oxide is 1.5-3:1.

[0012] Furthermore, the electromagnetic wave-absorbing component in the electromagnetic anti-seepage layer is wave-absorbing micron copper powder, and the content of wave-absorbing micron copper powder is 5%-11% of the total mass of the waterproof coating. The waterproof coating also includes 15%-22% polyurethane, 5%-8% sodium alginate, and 50%-65% water, based on the percentage of the total mass of the coating.

[0013] Furthermore, the microwave-absorbing micron copper powder accounts for 8%-11% of the total mass of the coating, and the electromagnetic microwave-absorbing component in the cement-based material is 70-80% of the mass of MgO.

[0014] Furthermore, the electromagnetic shielding door connects the concrete canvas into a sealed section through the door frame. An electromagnetic shielding curtain is installed inside the door frame. The electromagnetic shielding curtain is made of electromagnetic shielding cloth. The electromagnetic shielding cloth inside the tent forms a secondary shielding defense line for the tent through the zipper door. The base fabric of the electromagnetic shielding cloth is a blend of aramid fiber and polyamide fiber, and the surface is covered with multiple layers of electromagnetic shielding nickel plating.

[0015] Furthermore, the compressive strength of the cement-based electromagnetic wave-absorbing canvas tent over 7 days is not less than 40 MPa, preferably more than 50 MPa; the absolute value of the reflection loss is not less than 18 dB, preferably more than 25 dB; and the bandwidth is in the range of 10-16 GHz, preferably in the range of 14-16 GHz.

[0016] Compared with existing technologies, the beneficial effects of this invention are:

[0017] 1) This invention achieves multi-layered, multi-material electromagnetic shielding. Structurally, it employs steel fiber spiral coils and carbon fiber spiral coils with wave-absorbing functions, further enhancing the electromagnetic shielding capability of the concrete canvas. The spiral shape provides a degree of elasticity, while the high strength and toughness of the steel fiber and carbon fiber components significantly improve the strength of the concrete canvas structure, further enhancing the impact resistance and service life of the concrete canvas tent. The hollow part of the canvas incorporates micron-sized titanium dioxide particles, or wave-absorbing ceramic particles made from micron-sized titanium dioxide, carbon powder, nano-ferric oxide, graphene oxide, and other electromagnetic wave-absorbing components on a fast-hardening, early-strength magnesium phosphate cement-based material, effectively increasing the absorption frequency band of the canvas tent and improving its electromagnetic shielding capability against complex external environments. After the tent is erected, micron-sized copper powder with electromagnetic wave-absorbing functions is added to the waterproof coating on the top layer of the canvas tent, forming a multi-layered electromagnetic frequency blocking effect. Furthermore, the use of excellent waterproof polyurethane-based materials enables it to withstand the impact of complex natural environments such as wind, rain, and snow.

[0018] 2) The canvas tent structure of this invention uses an air bladder as the inner liner, which can be quickly inflated during use, making it convenient to carry and use. In terms of materials, it uses fast-hardening, early-strength magnesium phosphate cement-based materials, enabling rapid and stable construction. The canvas tent uses an electromagnetically shielded door and an electromagnetically shielded cloth curtain as two lines of electromagnetic protection, ensuring both good electromagnetic shielding and normal functionality.

[0019] 3) This invention uses airbags that inflate to form the tent's outline during use. Multiple pieces of cement-based electromagnetic absorbing canvas are connected together with U-shaped nails to form a closed bag. The airbags, acting as the inner lining of the bag, do not need to be connected to the canvas. An electromagnetic shielding door is installed at the bag's opening, forming a closed electromagnetic shielding space with the canvas bag. After inflation, the airbags form the tent shape and rise with the airbags during inflation, without the cement-based electromagnetic absorbing canvas itself cracking. After inflation, water is sprayed onto the outer layer of the canvas tent, and it is cured at room temperature to achieve stable strength. To prevent electromagnetic leakage caused by opening the door, an electromagnetic shielding fabric curtain is used inside the tent as a second layer of protection. Finally, a polyurethane-based waterproof material containing microwave-absorbing components is coated onto the densely woven surface of the cement-based electromagnetic absorbing canvas to form an electromagnetic anti-seepage layer, meeting the need for rapid tent setup in complex environments.

[0020] Cement-based electromagnetic wave-absorbing canvas tents, as a semi-permanent defensive fortification, not only need to improve their strength and electromagnetic shielding effect, but also need to have good heat insulation, thermal insulation, and rainproofing effects. The canvas structure and the dense structure formed by the material itself can meet these requirements. In addition, the use of polyurethane-based waterproof coating on the exterior of the tent makes it able to withstand complex external natural disasters. This invention enables the rapid construction of electromagnetic wave-absorbing structures to meet the rapid electromagnetic stealth requirements of personnel, equipment, and structural targets, and has significant research and application value in military and civilian protective engineering.

[0021] 4) In the preferred embodiment of the present invention, the absolute value of the reflection loss is not less than 25dB, the bandwidth is in the range of 14-16GHz, the wear resistance performance index is WR-I, and the impact strength performance index is WR-II. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of a cement-based electromagnetic wave-absorbing canvas tent.

[0023] Figure 2 This is a cross-sectional schematic diagram of a cement-based electromagnetic wave-absorbing canvas tent.

[0024] In the diagram, 1-cement-based electromagnetic wave-absorbing canvas, 2-U-shaped nail, 3-airbag, 4-electromagnetic shielding door, 11-electromagnetic anti-seepage layer, 12-top layer, 13-hollow layer, 14-densely woven bottom layer, 15-spacer yarn I, 16-spacer yarn II. Detailed Implementation

[0025] The present invention will be further explained below with reference to embodiments, but these are not intended to limit the scope of protection of this application.

[0026] The present invention provides a cement-based electromagnetic wave-absorbing canvas tent, the tent comprising an airbag 3, several pieces of cement-based electromagnetic wave-absorbing canvas 1 laid on the outer surface of the airbag, U-shaped nails 2 for connecting different pieces of cement-based electromagnetic wave-absorbing canvas, an electromagnetic shielding door 4 for entry and exit, and an electromagnetic anti-seepage layer 11 disposed on the outer surface of the cement-based electromagnetic wave-absorbing canvas.

[0027] The cement-based electromagnetic wave-absorbing canvas includes a top layer 12, a hollow layer 13, and a densely woven bottom layer 14 arranged from top to bottom. Between the top layer and the densely woven bottom layer, there are intermediate spacer yarns I and intermediate yarns II. Intermediate yarn I is made of steel fiber spiral coils with wave-absorbing function, and spacer yarn II is made of carbon fiber spiral coils with wave-absorbing function. The two intermediate yarns, together with the top layer and the densely woven bottom layer, form a three-dimensional skeleton structure of concrete canvas. Cement-based material containing electromagnetic wave-absorbing components is poured from the top layer into the hollow layer, vibrated and filled into the entire three-dimensional skeleton. A densely woven surface layer is then laid on the outside of the top layer to obtain the cement-based electromagnetic wave-absorbing canvas.

[0028] Multiple pieces of cement-based electromagnetic absorbing canvas are connected together with U-shaped nails to form a closed bag. An air bladder serves as the inner lining of the bag and does not need to be connected to the canvas. An electromagnetic shielding door is installed at the bag opening, forming a closed electromagnetic shielding space with the canvas bag. When inflated, the air bladder forms a tent shape. During inflation, the bag expands along with the air bladder, and the cement-based electromagnetic absorbing canvas itself does not crack. After inflation, water is sprayed onto the outer layer of the canvas tent, and it is cured at room temperature to achieve stable strength. Finally, a polyurethane-based waterproof coating containing electromagnetic absorbing components is applied to the densely woven surface of the cement-based electromagnetic absorbing canvas to form an electromagnetic anti-seepage layer, thus obtaining the cement-based electromagnetic absorbing canvas tent.

[0029] The top and bottom layers of the cement-based electromagnetic absorbing canvas are made of polyester resin (PET). The fabrics of the top layer 12 and the bottom layer 14 are woven into a mesh shape using warp yarns along the warp direction and weft yarns along the weft direction. The shape and size of the mesh can be varied according to the weaving parameters. The mesh size of the top layer 12 is controlled so that its maximum diameter is larger than the particle diameter of the magnesium phosphate component and the electromagnetic shielding component, allowing the matrix (magnesium phosphate cement containing the electromagnetic absorbing component) to smoothly fill the three-dimensional fabric. The minimum diameter of the mesh size of the bottom layer 14 is larger than the diameter of a water molecule, allowing water to pass through the fabric. Furthermore, the minimum diameter of the mesh size of the bottom layer 14 is smaller than the particle diameter of the magnesium phosphate component and the electromagnetic shielding component, preventing leakage of the filling material.

[0030] Furthermore, the cement-based material containing electromagnetic absorbing components includes both cement-based components and electromagnetic absorbing components. The mixture of electromagnetic absorbing components and cement-based components is stirred at 90 r / min for 10 minutes until homogeneous, forming a uniform electromagnetic absorbing magnesium phosphate dry powder material, which is the cement-based material containing electromagnetic absorbing components.

[0031] The electromagnetic absorbing components are micron-sized titanium dioxide particles, or absorbing ceramic particles, carbon powder, nano-iron oxide, graphene oxide, etc., made of micron-sized titanium dioxide.

[0032] The preparation of microwave absorbing ceramic particles involved weighing clay, micron-sized titanium dioxide, magnesium carbonate, and sodium sulfate at mass percentages of 85%, 10%, 3%, and 2%, respectively, and then mixing, granulating, and firing (heating to 1120℃ at a rate of 5℃ / min, calcining at a constant temperature for 45 min, and then cooling to room temperature in the furnace) to obtain microwave absorbing ceramic particles with a compressive strength of 9.8 MPa, a particle size of 5–10 mm, and an apparent density of 1.37 g / cm³. 3 .

[0033] Among them, charcoal powder: magnetic bamboo charcoal can be prepared using bamboo powder and impregnation-pyrolysis method as an electromagnetic wave absorbing material.

[0034] The cement-based components include phosphate, high-iron fly ash, borax, and MgO. The MgO is calcined at 1500℃ for 45 min, with a screened particle size of 15 μm; the screened high-iron fly ash has a particle size between 30-45 micrometers and a density greater than 2.8 g / cm³. 3 Potassium dihydrogen phosphate was selected as the phosphate. The mass ratio was MgO: high-iron fly ash: potassium dihydrogen phosphate: borax = 1:0.3:0.75:0.05.

[0035] Furthermore, the mixed electromagnetic absorbing phosphate cement-based dry powder is filled from the top layer into the hollow layer of a 5000mm×3000mm×50mm canvas. After being vibrated evenly, a densely woven top layer is laid on the top layer of the canvas to form a cement-based electromagnetic absorbing canvas.

[0036] Furthermore, the electromagnetic shielding door connects the concrete canvas into a sealed section via the door frame. An electromagnetic shielding curtain, made of electromagnetic shielding fabric, is installed inside the door frame. This electromagnetic shielding fabric forms a secondary shielding barrier within the tent via a zippered door. The base layer of the electromagnetic shielding fabric is a blend of aramid and polyamide fibers, covered with multiple layers of nickel-plated electromagnetic shielding material. To ensure optimal electromagnetic shielding, the electromagnetic shielding door and the electromagnetic shielding curtain should not be opened simultaneously. The door panel of the electromagnetic shielding door is not foldable.

[0037] The electromagnetic anti-seepage layer is formed by coating a uniformly mixed electromagnetic absorbing component and an anti-seepage binder. The electromagnetic absorbing component is microwave-absorbing micron-sized copper powder (copper powder content accounts for 5%-11% of the total mass of the coating), and the anti-seepage binder is: based on the total mass of the coating, weigh 15%-22% polyurethane, 5%-8% sodium alginate, and 50%-65% water.

[0038] The microwave-absorbing micron copper powder accounts for 8%-11% of the total mass of the coating, and the electromagnetic absorbing component in the hollow layer is 70-80% of the mass of MgO.

[0039] As a new product for disaster relief and military applications, cement-based electromagnetic wave-absorbing canvas tents must possess the ability to be rapidly prototyped and used in harsh environments to ensure that their use is not limited by time, space, or environment. This is the original intention behind the development of concrete tents. To verify this capability of cement-based electromagnetic wave-absorbing canvas tents, ANSYS finite element analysis was performed on the tent's shape, and tests were conducted on the waterproof performance, abrasion resistance, and impact resistance of the concrete canvas tents.

[0040] Example 1

[0041] In all three groups of experiments, the magnesium-to-phosphorus mass ratio (M / P, i.e., the mass ratio of magnesium oxide to potassium dihydrogen phosphate) was set to 1:0.75, and the mass ratio of MgO: high-iron fly ash: potassium dihydrogen phosphate: borax = 1:0.3:0.75:0.05. The cement-based electromagnetic absorbing canvas prepared by each group underwent compression, flexural, and electromagnetic protection tests. The electromagnetic absorbing component consisted of three materials: absorbing ceramic particles made of micron-sized titanium dioxide, nano-ferric oxide, and graphene oxide, with a mass ratio of 2:1:1. The experimental results are shown below:

[0042] The experiment was divided into 3 groups: In group 1, the electromagnetic absorbing component in the hollow layer was 60% of the mass of MgO, and the proportion of micron-sized copper powder in the total mass of the electromagnetic anti-seepage layer was changed. The results are shown in Table 1.

[0043] Table 1

[0044]

[0045] In Group 2, the electromagnetic absorbing component in the hollow layer was 75% of the MgO mass. The proportion of micron-sized copper powder in the total mass of the electromagnetic anti-seepage layer was changed, and the results are shown in Table 2.

[0046] Table 2

[0047]

[0048] In Group 3, the electromagnetic absorbing component in the hollow layer was 90% of the MgO mass. The proportion of micron-sized copper powder in the total mass of the electromagnetic anti-seepage layer was changed, and the results are shown in Table 3.

[0049]

[0050] The test results clearly show that when the electromagnetic absorbing component accounts for 75% of the MgO mass and the micron-sized copper powder accounts for 8% of the total mass of the electromagnetic waterproof layer, the compressive strength of the magnesium phosphate cement concrete canvas tent after 7 days of curing is greater than 50 MPa. The wear loss performance index of the above group is WR-I, and the impact strength performance index is WR-II, meeting the requirements for concrete tent use. Simultaneously, based on the water absorption rate, tensile strength, and elongation at break of the polyurethane-based coating, the waterproof rating is determined to be Level 1, indicating good water resistance. The cement-based electromagnetic absorbing canvas tent, after the addition of the electromagnetic absorbing component, exhibits excellent electromagnetic protection performance, mechanical properties, and waterproof performance.

[0051] Example 2

[0052] In this embodiment, the electromagnetic absorbing component consists of four substances: absorbing ceramic particles made of micron-sized titanium dioxide, carbon powder, nano-iron oxide, and graphene oxide, in a ratio of 1.5-3:1:1:1.

[0053] Example 3

[0054] In this embodiment, the electromagnetic absorbing component consists of absorbing ceramic particles made of micron-sized titanium dioxide, carbon powder, nano-iron oxide, and other substances, with a mass ratio of 2:1:1.

[0055] In the above embodiments, the compressive strength of the cement-based electromagnetic wave-absorbing canvas tent after 7 days is not less than 40 MPa, preferably above 50 MPa; the absolute value of the reflection loss is not less than 18 dB, preferably greater than 25 dB; and the bandwidth is in the range of 10-16 GHz, preferably in the range of 14-16 GHz. Before water spraying, the cement-based electromagnetic wave-absorbing canvas tent is a composite material composed of three-dimensional fabric, cement-based components, and electromagnetic wave-absorbing components. The thickness of the three-dimensional fabric is 40 mm to 60 mm, which is easy to curl. After the airbag is inflated, it forms the required spatial contour. After water spraying, a high-strength cement-based electromagnetic wave-absorbing canvas tent with electromagnetic protection performance is obtained. At the same time, two electromagnetic shielding defense lines are set at the entrance and exit. As a highly efficient electromagnetic protection building, it can be widely used.

[0056] Any aspects not covered in this invention are applicable to existing technologies.

Claims

1. A cement-based electromagnetic wave-absorbing canvas tent, characterized in that, The tent includes an airbag, several pieces of cement-based electromagnetic absorbing canvas laid on the outer surface of the airbag, U-shaped nails for connecting different pieces of cement-based electromagnetic absorbing canvas, an electromagnetic shielding door for entry and exit, and an electromagnetic anti-seepage layer set on the outer surface of the cement-based electromagnetic absorbing canvas. The cement-based electromagnetic wave-absorbing canvas comprises a top layer, a hollow layer, and a densely woven bottom layer arranged from top to bottom. Between the top layer and the densely woven bottom layer, there are intermediate spacer yarns I and intermediate yarns II. Intermediate yarn I is made of steel fiber spiral coils with wave-absorbing function, and spacer yarn II is made of carbon fiber spiral coils with wave-absorbing function. The two intermediate yarns, together with the top layer and the densely woven bottom layer, constitute the three-dimensional skeleton structure of the cement-based electromagnetic wave-absorbing canvas. Cement-based material containing electromagnetic wave-absorbing components is poured from the top layer into the hollow layer, vibrated and filled into the entire three-dimensional skeleton. A densely woven surface layer is then laid on the outside of the top layer to obtain the cement-based electromagnetic wave-absorbing canvas. Multiple pieces of cement-based electromagnetic absorbing canvas are connected together with U-shaped nails to form a closed bag. The air bladder serves as the inner lining of the bag and does not need to be connected to the canvas. An electromagnetic shielding door is installed at the bag opening to form a closed electromagnetic shielding space with the canvas bag. After the air bladder is inflated, it can form a tent shape. During the inflation process, the bag can bulge with the air bladder, and the cement-based electromagnetic absorbing canvas itself will not crack. After inflation, water is sprayed on the outer surface of the canvas tent and cured at room temperature to form stable strength. Finally, a waterproof coating containing electromagnetic absorbing components is applied to the densely woven surface of the cement-based electromagnetic absorbing canvas to form an electromagnetic anti-seepage layer, thus obtaining the cement-based electromagnetic absorbing canvas tent.

2. The cement-based electromagnetic wave-absorbing canvas tent according to claim 1, characterized in that, The electromagnetic anti-seepage layer has a thickness of 8-12mm, the overall thickness of the cement-based electromagnetic absorbing canvas is 40-60mm, and the total height and number of turns of the carbon fiber spiral coil and the steel fiber spiral coil can be adapted to the thickness of the canvas.

3. The cement-based electromagnetic wave-absorbing canvas tent according to claim 1, characterized in that, The cement-based material containing electromagnetic absorbing components includes cement-based components and electromagnetic absorbing components. The electromagnetic absorbing components in the cement-based material containing electromagnetic absorbing components are at least one of micron-sized titanium dioxide particles, or absorbing ceramic particles made of micron-sized titanium dioxide, carbon powder, nano-iron oxide, graphene oxide, and multi-walled carbon nanotubes. The cement-based components include phosphates, high-iron fly ash, borax, and MgO.

4. The cement-based electromagnetic wave-absorbing canvas tent according to claim 3, characterized in that, The electromagnetic absorbing component includes at least absorbing ceramic particles made of micron-sized titanium dioxide and nano-iron oxide, and also includes carbon powder or graphene oxide, wherein the mass ratio of absorbing ceramic particles to nano-iron oxide is 1.5-3:

1.

5. The cement-based electromagnetic wave-absorbing canvas tent according to claim 3, characterized in that, The preparation process of the microwave absorbing ceramic particles is as follows: clay, micron-sized titanium dioxide, magnesium carbonate, and sodium sulfate are weighed at mass percentages of 85%, 10%, 3%, and 2%, respectively, and then mixed, granulated, and fired sequentially to obtain microwave absorbing ceramic particles with a compressive strength of 9.8 MPa, a particle size of 5–10 mm, and an apparent density of 1.37 g / cm³. 3 The firing process is as follows: the temperature is increased to 1120℃ at a rate of 5℃ / min, and calcined at a constant temperature for 45 minutes, and then cooled to room temperature with the furnace.

6. The cement-based electromagnetic wave-absorbing canvas tent according to claim 3, characterized in that, The electromagnetic wave-absorbing component in the electromagnetic anti-seepage layer is wave-absorbing micron copper powder, and the content of wave-absorbing micron copper powder is 5%-11% of the total mass of the waterproof coating. The waterproof coating also includes 15%-22% polyurethane, 5%-8% sodium alginate, and 50%-65% water, based on the percentage of the total mass of the coating.

7. The cement-based electromagnetic wave-absorbing canvas tent according to claim 6, characterized in that, The microwave-absorbing micron copper powder accounts for 8%-11% of the total mass of the coating, and the electromagnetic absorbing component in the cement-based material is 70-80% of the mass of MgO.

8. The cement-based electromagnetic wave-absorbing canvas tent according to claim 1, characterized in that, The electromagnetic shielding door connects the concrete canvas into a sealed section through the door frame. An electromagnetic shielding curtain is installed inside the door frame. The electromagnetic shielding curtain is made of electromagnetic shielding cloth. The electromagnetic shielding cloth inside the tent forms a secondary shielding defense line through the zipper door. The base layer of the electromagnetic shielding cloth is a blend of aramid fiber and polyamide fiber, and the surface is covered with multiple layers of electromagnetic shielding nickel plating.

9. The cement-based electromagnetic wave-absorbing canvas tent according to claim 1, characterized in that, The cement-based electromagnetic wave-absorbing canvas tent has a compressive strength of not less than 40 MPa over 7 days; an absolute value of reflection loss of not less than 18 dB; and a bandwidth in the range of 10-16 GHz.

10. The cement-based electromagnetic wave-absorbing canvas tent according to claim 9, characterized in that, The cement-based electromagnetic wave-absorbing canvas tent has a compressive strength of over 50 MPa after 7 days; an absolute value of reflection loss greater than 25 dB; and a bandwidth in the range of 14-16 GHz.

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