Preparation method of electromagnetic shielding high-strength supersulfate cement-based material

Abstract

The invention discloses a preparation method of an electromagnetic shielding high-strength supersulfate cement-based material, which comprises the following steps: (1) uniformly mixing a powder material with an electromagnetic wave absorption function with saturated lime water, then adding basalt fibers, reacting under a heat preservation condition, then separating out the basalt fibers, and drying to obtain modified fibers; and (2) carbonizing the coal gangue particles, mixing the carbonized coal gangue particles with a saturated aqueous solution of a magnesium source, and mixing the coal gangue particles with alkali liquor after sufficient absorption. After standing, placing the coal gangue particles in saturated lime water for reaction, and then calcining the coal gangue particles to obtain the modified coal gangue fine aggregate. And (2) taking granulated blast furnace slag powder, coarse aggregate, the modified coal gangue fine aggregate, the modified fiber, paraffin particles and the like as raw materials, and uniformly stirring with water to obtain the super sulfate cement-based material. The process not only solves the problem that the mechanical property of the material is reduced due to the addition of the electromagnetic shielding component, but also reduces the possibility that the cement-based material is detected by infrared.

Description

Technical Field

[0001] The present invention relates to the technical field of supersulfate cement-based materials, and particularly to a preparation method of an electromagnetic shielding high-strength supersulfate cement-based material. Background Art

[0002] Disclosing the information of this background art section is only intended to enhance the understanding of the overall background of the present invention, and is not necessarily to be regarded as an admission or an implication in any form that this information constitutes the prior art already known to those of ordinary skill in the art.

[0003] Compared with traditional portland cement, supersulfate cement is a green and low-carbon cementitious material with blast furnace slag as the main cementitious component. This is because the production process of supersulfate cement does not involve long-time high-temperature calcination processes, not only with low carbon emissions, but also capable of realizing the resource utilization of industrial solid wastes. Electromagnetic shielding concrete, also called radiation shielding concrete, refers to building materials with the ability to reduce and shield the penetration of radioactive rays. Currently, it has been widely used in buildings such as electronic equipment rooms, laboratories, hospitals, and communication base stations. In addition, electromagnetic shielding concrete is also widely used in military building facilities, which helps to prevent the leakage of internal electromagnetic signals and external electromagnetic interference. Moreover, with the popularization and wide use of electronic devices, the pollution problem caused by electromagnetic radiation has attracted people's attention, and electromagnetic shielding concrete is an effective way to solve the above problems.

[0004] Adding components with the ability to absorb and attenuate electromagnetic waves (such as metal powders, ferrites, graphite powders, etc.) to supersulfate cement can not only achieve the function of electromagnetic shielding, but also contribute to the large-scale utilization of industrial solid wastes. However, the direct addition of these components will, on the one hand, lead to a decline in the mechanical properties of the material, and on the other hand, after these components absorb electromagnetic waves and convert them into heat energy, it is easy to cause a temperature rise, thereby increasing the possibility of being detected by infrared, which is not conducive to the concealment and protection of some important facilities. Summary of the Invention

[0005] The present invention provides a preparation method of an electromagnetic shielding high-strength supersulfate cement-based material. This process not only solves the problem of the decline in the mechanical properties of the cement-based material caused by the addition of electromagnetic shielding components, but also reduces the possibility of the cement-based material being detected by infrared. Specifically, the technical solution of the present invention is as follows.

[0006] A preparation method of an electromagnetic shielding high-strength supersulfate cement-based material includes the following steps: (1)Mix the powder material with electromagnetic wave absorption function and saturated lime water evenly, then add basalt fiber and react under continuous stirring and heat preservation conditions. After completion, separate the basalt fiber and dry it to obtain the modified fiber with electromagnetic shielding function for standby.

[0007] (2)Carry out carbonization treatment on coal gangue particles at the fine aggregate level, then mix the obtained coal gangue particles with a saturated aqueous solution of a magnesium source. After sufficient absorption, mix the coal gangue particles with an alkali solution. Let it stand and then heat and react the obtained coal gangue particles in saturated lime water. After completion, separate the coal gangue particles and calcine them in a protective atmosphere to obtain modified coal gangue fine aggregate with electromagnetic shielding function for standby.

[0008] (3)Mix blast furnace slag powder, coarse aggregate, the modified coal gangue fine aggregate, fly ash, silica fume, the modified fiber, paraffin particles, water reducing agent, sulfate activator, and alkali activator evenly, and then add mixing water and stir evenly to obtain a supersulfate cement-based material.

[0009] Further, in step (1), the powder material includes at least one of magnetite, metal powder, graphite powder, graphene, etc. Optionally, the metal powder includes at least one of iron powder, copper powder, nickel powder, etc.

[0010] Further, in step (1), the ratio of the powder material to saturated lime water is 1 g: 10 - 30 ml.

[0011] Further, in step (1), the ratio of the basalt fiber to saturated lime water is 1 g: 25 - 50 ml. Optionally, the length of the basalt fiber is 1 - 5 cm.

[0012] Further, in step (1), the heat preservation temperature is 45 - 60 °C and the reaction time is 9 - 12 hours.

[0013] Further, in step (1), the drying temperature is 80 - 130 °C and the time is 20 - 30 min.

[0014] Further, in step (2), the temperature of the carbonization treatment is 500 - 620 °C and the time is 1.5 - 3 hours.

[0015] Further, in step (2), the ratio of the coal gangue particles to the saturated aqueous solution of the magnesium source is 1 g: 20 - 40 ml. Optionally, the magnesium source includes at least one of magnesium chloride, magnesium sulfate, magnesium nitrate, etc.

[0016] Further, in step (2), the absorption time is 20 - 30 min.

[0017] Further, in step (2), the ratio of the coal gangue particles to the alkali solution is 1 g: 3 - 7 ml. Optionally, the concentration of the alkali solution is 2 - 5 mol / L. The alkali solution includes at least one of sodium hydroxide solution, potassium hydroxide solution, ammonia water, sodium carbonate solution, etc.

[0018] Further, in step (2), the standing time is 60 - 75 min.

[0019] Further, in step (2), the ratio of the coal gangue particles to the saturated lime water is 1 g: 10 - 25 ml.

[0020] Further, in step (2), the temperature of the heating reaction is 50 - 60 °C, and the reaction time is 8 - 10 hours.

[0021] Further, in step (2), the temperature of the calcination treatment is 520 - 580 °C, and the time is 1 - 2 hours. Optionally, the protective atmosphere includes any one of nitrogen, argon, etc.

[0022] Further, in step (3), the proportions of each component are as follows: granulated blast furnace slag powder 105 - 127 parts by weight, coarse aggregate 262 - 330 parts by weight, modified coal gangue fine aggregate 121 - 165 parts by weight, fly ash 13 - 25 parts by weight, silica fume 7 - 19 parts by weight, modified fiber 8 - 14 parts by weight, paraffin wax particles 6 - 10 parts by weight, water reducing agent 2 - 2.5 parts by weight, sulfate activator 13 - 22 parts by weight, alkali activator 3.2 - 5.2 parts by weight.

[0023] Further, in step (3), the mixing water is added according to a water - cement ratio of 0.35 - 0.42. That is, the mass of the mixing water is 0.35 - 0.42 times the total mass of the granulated blast furnace slag powder, fly ash, and silica fume.

[0024] Further, in step (3), the softening temperature of the paraffin wax is not lower than 80 °C. Optionally, the fineness of the paraffin wax particles is 10 - 20 mesh.

[0025] Further, in step (3), the water reducing agent includes any one of polycarboxylate water reducing agent, naphthalene - based water reducing agent, lignosulfonate water reducing agent, etc.

[0026] Further, in step (3), the sulfate activator includes at least one of desulfurized gypsum, phosphogypsum, fluorogypsum, etc.

[0027] Further, in step (3), the alkali activator includes at least one of calcium hydroxide, carbide slag, etc.

[0028] Compared with the prior art, the present invention has at least the following beneficial technical effects: Compared with the traditional method of directly adding electromagnetic shielding components to cement-based materials, the supersulfate cement-based material of the present invention uses modified fibers and modified coal gangue fine aggregates with electromagnetic shielding functions, and through the cooperation with paraffin particles, not only improves the mechanical properties of the cement-based material, but also reduces the possibility of the cement-based material being detected by infrared. The reasons are as follows: On the one hand, the present invention uses saturated lime water containing electromagnetic wave absorption functional powder materials to surface-modify basalt fibers. During this process, the surface of the basalt fibers forms an active surface after being excited in an alkaline environment, and it further reacts with calcium ions to form calcium silicate hydrate (C-S-H) and calcium aluminate hydrate (C-A-H) which are solidified on the fiber surface. At the same time, electromagnetic wave absorption functional materials are doped in the C-S-H and C-A-H. This not only roughens the surface of the basalt fibers, effectively increasing the bonding force with the concrete matrix and improving the mechanical properties of the cement-based material, but also combines the electromagnetic wave absorption functional materials on the fiber surface during the above-mentioned roughening process. This not only avoids the decline in mechanical properties caused by directly dispersing the electromagnetic wave absorption functional materials in the cement-based material, but also the doping and loading of these electromagnetic wave absorption functional materials help to further improve the surface roughness of the fibers. On the other hand, the present invention first carbonizes coal gangue particles to convert the organic matter therein into carbonaceous matter, which not only eliminates the possible instability problems that may occur in the later stage after the coal gangue is directly incorporated into the cement-based material, but also exactly uses the pores formed by the volatile components in the organic matter to absorb magnesium ions. After mixing the treated coal gangue particles with alkali solution, the magnesium ions are converted into magnesium hydroxide and solidified in the coal gangue. At the same time, the surface of the coal gangue is activated under the excitation of the alkali solution, and it further reacts with saturated lime water to form C-S-H and C-A-H in the pores of the coal gangue particles, which helps to improve the strength of the coal gangue particles. After calcination, the magnesium hydroxide is converted into magnesium oxide, making the coal gangue particles have electromagnetic shielding functions. After adding the coal gangue particles as fine aggregates to the cement-based material, it not only improves the electromagnetic shielding ability, but also avoids the decline in mechanical properties caused by directly dispersing the electromagnetic wave absorption functional materials in the cement-based material. In addition, the C-S-H and C-A-H also help to promote the hydration of the cement components in the cement-based material, increasing the formation amount of the cementitious products, thereby contributing to the improvement of the mechanical properties of the supersulfate cement-based material of the present invention. On the other hand, after the paraffin particles are dispersed in the cement-based material, they can store the heat generated after the electromagnetic wave absorption functional materials absorb waves by using the characteristics of softening and absorbing heat and gradually release it, reducing the amplitude of the temperature rise of the cement-based material, which is conducive to reducing the infrared detectability. Description of the Drawings

[0029] The accompanying drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings, where: Figure 1 Sample diagram of the modified coal gangue fine aggregate prepared for Example 1 below.

[0030] Figure 2 Compressive strength test diagram for Example 1 below. Specific embodiments

[0031] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. The experimental methods without specific conditions noted in the following embodiments are generally carried out under conventional conditions or according to the conditions recommended by the manufacturer. The present invention will be further described in conjunction with the specific embodiments.

[0032] Example 1 The preparation of a preparation method of an electromagnetic shielding high-strength supersulfate cement-based material includes the following steps: (1) Mix graphite powder with a fineness of 300 meshes and saturated lime water in a ratio of 1 g: 20 ml, stir evenly, and then add basalt fibers with a length of 1 cm, and the ratio of it to the saturated lime water is 1 g: 40 ml. Then heat to 55 °C and continuously stir and react at this temperature for 10 hours. After completion, filter out the basalt fibers, dry them at 110 °C for 30 min to obtain modified fibers.

[0033] (2) Heat the coal gangue fine aggregate with a fineness distribution between 0.5 and 1.5 mm to 550 °C in a nitrogen protection atmosphere and keep it warm for 2.5 hours for carbonization treatment. After completion, cool to room temperature, mix the obtained carbonized coal gangue fine aggregate with saturated magnesium sulfate solution in a ratio of 1 g: 30 ml, and let it stand and absorb for 20 min. Then filter out the coal gangue fine aggregate, and add 2 mol / L sodium hydroxide solution dropwise in a ratio of 1 g: 7 ml. After completion, let it stand for 60 min. Then filter out the coal gangue fine aggregate, mix it with saturated lime water in a ratio of 1 g: 20 ml, and heat to 55 °C and keep it warm for 10 hours. After completion, filter out the coal gangue fine aggregate, and calcine it at 580 °C in a nitrogen atmosphere for 1 hour to obtain modified coal gangue fine aggregate (as Figure 1 shown), for standby.

[0034] (3) Take the following raw materials in the following proportions: 110 parts by weight of granulated blast furnace slag powder, 290 parts by weight of coarse aggregate, 144 parts by weight of the modified coal gangue fine aggregate prepared in this example, 17 parts by weight of fly ash, 13 parts by weight of silica fume, 11 parts by weight of the modified fiber prepared in this example, 8 parts by weight of paraffin particles, 2.2 parts by weight of polycarboxylate superplasticizer, 20 parts by weight of desulfurized gypsum powder, and 4 parts by weight of calcium hydroxide. Among them: The coarse aggregate is crushed stone with a particle size distribution between 1 and 2 cm. The paraffin particles have a fineness of 10 mesh and a softening temperature of about 80-83°C. Mix the above raw materials evenly, and then add mixing water according to a water-cement ratio of 0.38 and stir evenly to obtain a supersulfate cement-based material.

[0035] Performance test: (1) Pour the cement-based material prepared in this example into a mold, demold it after hardening and forming, and cure it under standard conditions for 28 days. Then, according to the "Standard for Test Methods of Physical and Mechanical Properties of Concrete" (GB / T 50081-2019), the compressive strength of the test specimens obtained is tested (as Figure 2 shown). (2) According to ASTM 4935 (flange coaxial method), test the electromagnetic wave shielding effectiveness (SE) of the test specimens prepared from the cement-based material of this example. (3) Radiate the test specimens prepared from the cement-based material of this example with electromagnetic waves for 1 hour, and after completion, use an infrared thermal imager to test the surface temperature rise value △T of the test specimens. The test results are: compressive strength = 56.11 MPa, SE = 79.4 dB, △T = 1.2°C.

[0036] Example 2 The preparation of a method for preparing an electromagnetic shielding high-strength supersulfate cement-based material includes the following steps: (1) Mix copper powder with a particle size distribution between 20 and 50 μm and saturated lime water in a ratio of 1 g:10 ml, stir evenly, and then add basalt fiber with a length of 3 cm, and its ratio to the saturated lime water is 1 g:25 ml. Then heat to 45°C and continuously stir and react at this temperature for 12 hours. After completion, filter out the basalt fiber and dry it at 80°C for 25 minutes to obtain modified fiber.

[0037] (2) Heat the coal gangue fine aggregate with a fineness distribution between 0.5 and 2 mm to 620 °C in a nitrogen-protected atmosphere and hold for 1.5 hours for carbonization treatment. After completion, cool to room temperature, mix the obtained carbonized coal gangue fine aggregate with a saturated magnesium nitrate solution in a ratio of 1 g: 40 ml, and let it stand for absorption for 20 min. Then filter out the coal gangue fine aggregate, and add 3.5 mol / L sodium carbonate solution dropwise in a ratio of 1 g: 6 ml. After completion, let it stand for 70 min. Then filter out the coal gangue fine aggregate, mix it with saturated lime water in a ratio of 1 g: 10 ml, and heat to 50 °C and hold for 9 hours. After completion, filter out the coal gangue fine aggregate, heat it to 530 °C in a nitrogen atmosphere and calcine for 2 hours to obtain a modified coal gangue fine aggregate for standby.

[0038] (3) Take raw materials in the following proportions: 127 parts by weight of granulated blast furnace slag powder, 330 parts by weight of coarse aggregate, 165 parts by weight of the modified coal gangue fine aggregate prepared in this example, 25 parts by weight of fly ash, 18 parts by weight of silica fume, 14 parts by weight of the modified fiber prepared in this example, 10 parts by weight of paraffin particles, 2.5 parts by weight of polycarboxylate superplasticizer, 22 parts by weight of phosphogypsum powder, and 5.2 parts by weight of carbide slag powder. Among them: the coarse aggregate is crushed stone with a particle size distribution between 1 and 2 cm. The fineness of the paraffin particles is 20 mesh, and its softening temperature is about between 87 and 92 °C. Mix the above raw materials evenly, and then add mixing water according to a water-cement ratio of 0.42 and stir evenly to obtain a supersulfate cement-based material.

[0039] Performance test: Test the 28-day compressive strength, shielding effectiveness (SE), and surface temperature rise value ΔT of the cement-based material prepared in this example. The test method is the same as that in Example 1 above. The test results are: compressive strength = 57.94 MPa, SE = 84.2 dB, ΔT = 0.9 °C.

[0040] Example 3 The preparation of a preparation method of an electromagnetic shielding high-strength supersulfate cement-based material includes the following steps: (1) Mix the powder material with electromagnetic wave absorption function (composed of nano-ferroferric oxide and graphene in a mass ratio of 1:10) with saturated lime water in a ratio of 1 g: 30 ml and stir evenly, then add basalt fiber with a length of 5 cm, and its ratio to the saturated lime water is 1 g: 50 ml. Then heat to 60 °C and continuously stir and react at this temperature for 9 hours. After completion, filter out the basalt fiber and dry it at 130 °C for 20 min to obtain a modified fiber.

[0041] (2) Heat the coal gangue fine aggregate with a fineness distribution between 0.5 and 2 mm to 500 °C in a nitrogen-protected atmosphere and keep it at this temperature for 3 hours for carbonization treatment. After completion, cool it to room temperature. Mix the obtained carbonized coal gangue fine aggregate with a saturated magnesium sulfate solution at a ratio of 1 g:20 ml and let it stand for absorption for 30 min. Then filter out the coal gangue fine aggregate and add 5 mol / L ammonia water dropwise at a ratio of 1 g:3 ml. After completion, let it stand for 75 min. Then filter out the coal gangue fine aggregate, mix it with saturated lime water at a ratio of 1 g:25 ml and heat it to 60 °C and keep it at this temperature for 8 hours. After completion, filter out the coal gangue fine aggregate and calcine it at 520 °C in a nitrogen atmosphere for 2 hours to obtain the modified coal gangue fine aggregate for standby.

[0042] (3) Take the following proportion of raw materials: 105 parts by weight of granulated blast furnace slag powder, 262 parts by weight of coarse aggregate, 121 parts by weight of the modified coal gangue fine aggregate prepared in this example, 13 parts by weight of fly ash, 7 parts by weight of silica fume, 8 parts by weight of the modified fiber prepared in this example, 6 parts by weight of paraffin particles, 2 parts by weight of lignosulfonate water reducer, 13 parts by weight of fluorogypsum powder, 3.2 parts by weight of carbide slag powder. Among them: the coarse aggregate is crushed stone with a particle size distribution between 1 and 2 cm. The fineness of the paraffin particles is 10 mesh, and the temperature at which it melts into a liquid state is about 92 °C. Mix the above raw materials evenly, and then add mixing water according to a water-cement ratio of 0.35 and stir evenly to obtain the supersulfate cement-based material.

[0043] Performance test: Test the 28-day compressive strength, shielding effectiveness (SE) and surface temperature rise value ΔT of the cement-based material prepared in this example. The test method is the same as that of Example 1 above. The test results are: compressive strength = 53.06 MPa, SE = 76.8 dB, ΔT = 1.6 °C.

[0044] Example 4 The preparation method of an electromagnetic shielding high-strength supersulfate cement-based material includes the following steps: Take the following proportion of raw materials: 110 parts by weight of granulated blast furnace slag powder, 290 parts by weight of coarse aggregate, 144 parts by weight of the modified coal gangue fine aggregate prepared in Example 1 above, 17 parts by weight of fly ash, 13 parts by weight of silica fume, 11 parts by weight of basalt fiber with a length of 1 cm, 5 parts by weight of graphite powder with a fineness of 300 mesh, 8 parts by weight of paraffin particles, 2.2 parts by weight of polycarboxylate water reducer, 20 parts by weight of desulfurized gypsum powder, 4 parts by weight of calcium hydroxide. Among them: the coarse aggregate is crushed stone with a particle size distribution between 1 and 2 cm. The fineness of the paraffin particles is 10 mesh, and its softening temperature is about between 80 and 83 °C. Mix the above raw materials evenly, and then add mixing water according to a water-cement ratio of 0.38 and stir evenly to obtain the supersulfate cement-based material.

[0045] Performance test: Test the 28-day compressive strength, shielding effectiveness (SE), and surface temperature rise value ΔT of the cement-based material prepared in this example. The test method is the same as that in Example 1 above. The test results are: compressive strength = 49.27 MPa, SE = 82.3 dB, ΔT = 1.8 °C.

[0046] Example 5 A preparation method for an electromagnetic shielding high-strength supersulfate cement-based material includes the following steps: (1) Mix fine coal gangue aggregates with a fineness distribution between 0.5 and 1.5 mm and saturated magnesium sulfate solution in a ratio of 1 g: 30 ml, and then let it stand for absorption for 20 min. Then filter out the fine coal gangue aggregates, and add 2 mol / L sodium hydroxide solution dropwise in a ratio of 1 g: 7 ml. After completion, let it stand for 60 min. Then filter out the fine coal gangue aggregates, mix it with saturated lime water in a ratio of 1 g: 20 ml, and heat it to 55 °C for heat preservation for 10 hours. After completion, filter out the fine coal gangue aggregates, and calcine it in a nitrogen atmosphere at 580 °C for 1 hour to obtain modified fine coal gangue aggregates for standby.

[0047] (2) Take raw materials in the following proportions: 110 parts by weight of granulated blast furnace slag powder, 290 parts by weight of coarse aggregates, 144 parts by weight of the modified fine coal gangue aggregates prepared in this example, 17 parts by weight of fly ash, 13 parts by weight of silica fume, 11 parts by weight of the modified fibers prepared in Example 1 above, 8 parts by weight of paraffin particles, 2.2 parts by weight of polycarboxylate superplasticizer, 20 parts by weight of desulfurized gypsum powder, and 4 parts by weight of calcium hydroxide. Among them: the coarse aggregates are gravel with a particle size distribution between 1 and 2 cm. The fineness of the paraffin particles is 10 mesh, and its softening temperature is about between 80 and 83 °C. Mix the above raw materials evenly, and then add mixing water according to a water-cement ratio of 0.38 and stir evenly to obtain a supersulfate cement-based material.

[0048] Performance test: Test the 28-day compressive strength, shielding effectiveness (SE), and surface temperature rise value ΔT of the cement-based material prepared in this example. The test method is the same as that in Example 1 above. The test results are: compressive strength = 47.34 MPa, SE = 51.6 dB, ΔT = 0.7 °C.

[0049] Example 6 A preparation method for an electromagnetic shielding high-strength supersulfate cement-based material includes the following steps: (1) Heat the coal gangue fine aggregate with a fineness distribution between 0.5 and 2 mm to 500 °C in a nitrogen-protected atmosphere and keep it at this temperature for 3 hours for carbonization treatment. After completion, cool it to room temperature. Mix the obtained carbonized coal gangue fine aggregate with a saturated magnesium sulfate solution at a ratio of 1 g:20 ml and let it stand for absorption for 30 min. Then filter out the coal gangue fine aggregate and add 5 mol / L ammonia water dropwise at a ratio of 1 g:3 ml. After completion, let it stand for 75 min. After completion, filter out the coal gangue fine aggregate and heat it to 520 °C in a nitrogen atmosphere for calcination treatment for 2 hours to obtain a modified coal gangue fine aggregate for standby.

[0050] (2) Take the following raw materials in proportion: 105 parts by weight of granulated blast furnace slag powder, 262 parts by weight of coarse aggregate, 121 parts by weight of the modified coal gangue fine aggregate prepared in this example, 13 parts by weight of fly ash, 7 parts by weight of silica fume, 8 parts by weight of the modified fiber prepared in Example 3 above, 6 parts by weight of paraffin particles, 2 parts by weight of lignosulfonate water reducer, 13 parts by weight of fluorogypsum powder, and 3.2 parts by weight of carbide slag powder. Among them: the coarse aggregate is crushed stone with a particle size distribution between 1 and 2 cm. The fineness of the paraffin particles is 10 mesh, and the temperature at which it melts into a liquid state is about 92 °C. Mix the above raw materials evenly, and then add mixing water according to a water-cement ratio of 0.35 and stir evenly to obtain a supersulfate cement-based material.

[0051] Performance test: Test the 28-day compressive strength, shielding effectiveness (SE), and surface temperature rise value ΔT of the cement-based material prepared in this example. The test method is the same as that in Example 1 above. The test results are: compressive strength = 43.62 MPa, SE = 78.1 dB, ΔT = 2.2 °C.

[0052] Example 7 The preparation of a method for preparing an electromagnetic shielding high-strength supersulfate cement-based material includes the following steps: Take the following raw materials in proportion: 127 parts by weight of granulated blast furnace slag powder, 330 parts by weight of coarse aggregate, 165 parts by weight of the modified coal gangue fine aggregate prepared in Example 2 above, 25 parts by weight of fly ash, 18 parts by weight of silica fume, 14 parts by weight of the modified fiber prepared in Example 2 above, 2.5 parts by weight of polycarboxylate water reducer, 22 parts by weight of phosphogypsum powder, and 5.2 parts by weight of carbide slag powder. Among them: the coarse aggregate is crushed stone with a particle size distribution between 1 and 2 cm. The fineness of the paraffin particles is 20 mesh, and its softening temperature is about between 87 and 92 °C. Mix the above raw materials evenly, and then add mixing water according to a water-cement ratio of 0.42 and stir evenly to obtain a supersulfate cement-based material.

[0053] Performance test: Test the 28-day compressive strength, shielding effectiveness (SE), and surface temperature rise value ΔT of the cement-based material prepared in this embodiment. The test method is the same as that in Example 1 above. The test results are as follows: compressive strength = 59.02 MPa, SE = 80.5 dB, ΔT = 4.6 °C.

[0054] The foregoing are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or equivalently replace some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A preparation method of an electromagnetic shielding high-strength supersulfate cement-based material, characterized in that, It includes the following steps: (1) Mix the powder material with electromagnetic wave absorption function and saturated lime water, stir evenly, then add basalt fiber and react under continuous stirring and heat preservation conditions; after completion, separate the basalt fiber, and after drying, the modified fiber with electromagnetic shielding function is obtained and reserved; (2) Carbonize the coal gangue particles at the fine aggregate level, then mix the obtained coal gangue particles with the saturated aqueous solution of the magnesium source, and after sufficient absorption, mix the coal gangue particles with the alkali solution; after standing, place the obtained coal gangue particles in saturated lime water for heating reaction; after completion, separate the coal gangue particles and calcine them in a protective atmosphere to obtain the modified coal gangue fine aggregate with electromagnetic shielding function and reserve it; (3) Mix blast furnace slag powder, coarse aggregate, the modified coal gangue fine aggregate, fly ash, silica fume, the modified fiber, paraffin particles, water reducing agent, sulfate activator, alkali activator evenly, and then add mixing water and stir evenly to obtain the supersulfate cement-based material.

2. The preparation method of the electromagnetic shielding high-strength supersulphate cement-based material according to claim 1, wherein In step (1), the powder material includes at least one of iron tetroxide, metal powder, graphite powder, and graphene; Optionally, in step (1), the metal powder includes at least one of iron powder, copper powder, and nickel powder.

3. The preparation method of the electromagnetic shielding high-strength supersulfate cement-based material according to claim 1, characterized in that, In step (1), the ratio of the powder material to saturated lime water is 1g: 10~30ml; Optionally, in step (1), the ratio of the basalt fiber to saturated lime water is 1g: 25~50ml; Optionally, in step (1), the length of the basalt fiber is 1~5cm.

4. The preparation method of the electromagnetic shielding high-strength supersulfate cement-based material according to claim 1, characterized in that In step (1), the heat preservation temperature is 45~60°C, and the reaction time is 9~12 hours; Optionally, in step (1), the drying temperature is 80~130°C, and the time is 20~30min.

5. The preparation method of the electromagnetic shielding high-strength supersulfate cement-based material according to claim 1, characterized in that, In step (2), the temperature of the carbonization treatment is 500~620°C, and the time is 1.5~3 hours; Optionally, in step (2), the absorption time is 20~30min; Optionally, in step (2), the standing time is 60~75min.

6. The preparation method of the electromagnetic shielding high-strength supersulfate cement-based material according to claim 1, characterized in that, In step (2), the ratio of the coal gangue particles to the saturated aqueous solution of the magnesium source is 1g: 20~40ml; Optionally, in step (2), the magnesium source includes at least one of magnesium chloride, magnesium sulfate, and magnesium nitrate; Optionally, in step (2), in step (2), the ratio of the coal gangue particles to the alkali solution is 1g: 3~7ml; Optionally, the concentration of the alkali solution is 2~5mol / L; Optionally, in step (2), the alkali solution includes at least one of sodium hydroxide solution, potassium hydroxide solution, ammonia water, and sodium carbonate solution.

7. The preparation method of the electromagnetic shielding high-strength supersulfate cement-based material according to claim 1, characterized in that, In step (2), the ratio of the coal gangue particles to saturated lime water is 1g: 10~25ml; Optionally, in step (2), the temperature of the heating reaction is 50~60°C, and the reaction time is 8~10 hours.

8. The preparation method of the electromagnetic shielding high-strength supersulfate cement-based material according to claim 1, characterized in that, In step (2), the temperature of the calcination treatment is 520~580°C, and the time is 1~2 hours; Optionally, in step (2), the protective atmosphere includes any one of nitrogen and argon.

9. The preparation method of the electromagnetic shielding high-strength supersulfate cement-based material according to claim 1, characterized in that In step (3), the proportions of the components are as follows: 105 - 127 parts by weight of granulated blast furnace slag powder, 262 - 330 parts by weight of coarse aggregate, 121 - 165 parts by weight of modified coal gangue fine aggregate, 13 - 25 parts by weight of fly ash, 7 - 19 parts by weight of silica fume, 8 - 14 parts by weight of modified fiber, 6 - 10 parts by weight of paraffin granules, 2 - 2.5 parts by weight of water reducing agent, 13 - 22 parts by weight of sulfate activator, and 3.2 - 5.2 parts by weight of alkali activator.

10. The preparation method of the electromagnetic shielding high-strength supersulfate cement-based material according to any one of claims 1-9, characterized in that, In step (3), the mixing water is added according to a water - cement ratio of 0.35 - 0.42; Optionally, in step (3), the softening temperature of the paraffin is not lower than 80 °C; Optionally, in step (3), the fineness of the paraffin granules is 10 - 20 mesh; Optionally, in step (3), the water reducing agent includes any one of polycarboxylate water reducing agent, naphthalene - based water reducing agent, and lignosulfonate water reducing agent; Optionally, in step (3), the sulfate activator includes at least one of desulfurized gypsum, phosphogypsum, and fluorogypsum; Optionally, in step (3), the alkali activator includes at least one of calcium hydroxide and carbide slag.

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