High-strength concrete and preparation method thereof

Abstract

The invention discloses high-strength concrete and a preparation method thereof, the high-strength concrete comprises the following components: an adhesive material, an active filler, a surface insulation electromagnetic shielding filler, a foaming agent and a water reducing agent, the surface insulation electromagnetic shielding filler is composed of surface insulation modified conductive fibers and a surface insulation sheet-shaped electromagnetic shielding material, the D50 diameter of the surface insulation modified conductive fibers is smaller than 25% of the radial size of the surface insulation sheet-shaped electromagnetic shielding material, and the thickness of the surface insulation sheet-shaped electromagnetic shielding material is smaller than 20% of the D50 diameter of the surface insulation modified conductive fibers. When the concrete is coagulated, foam is generated through the foaming agent to extrude the electromagnetic shielding filler to gather to form a linear and sheet-shaped electromagnetic shielding microstructure, and the electromagnetic shielding capability and the sound absorption capability of the concrete are improved under the condition that low doping does not affect the strength of the concrete.

Description

Technical Field

[0001] The present invention relates to the field of concrete materials, and particularly to a high-strength concrete and a preparation method thereof. Background Art

[0002] With the rapid development of wireless communication and the wide use of electronic devices, the dangerous radiation amount of electromagnetic waves is increasing. Electromagnetic radiation will affect people's physical health, cause serious interference to surrounding electronic instruments, and at the same time, electromagnetic radiation will also lead to information leakage and affect information security. As a common electromagnetic wave transmission material, the improvement of the electromagnetic shielding ability of building concrete structures is the most direct and lowest-cost way, and it is even the preferred way in special fields such as nuclear power and underground structures.

[0003] CN109336515A discloses a high-frequency electromagnetic shielding concrete and a preparation method thereof. Its composition includes: ordinary Portland cement, stainless steel fibers, graphite, coke, water, and sand. This technical solution prepares a concrete with electromagnetic shielding function by adding graphite, coke, and stainless steel fibers with electromagnetic shielding function to the concrete.

[0004] CN 112110700 A discloses an electromagnetic shielding concrete and a preparation method thereof, which relates to the technical field of concrete materials. It is prepared from the following concrete raw materials in parts by weight: 450-550 parts of cement, 950-1050 parts of crushed stone, 500-600 parts of sand, 100-160 parts of zeolite powder, and 120-180 parts of water; the concrete raw materials further include additives and regulators; the additives include the following raw materials in parts by weight: 4-8 parts of carbon fiber and 2-8 parts of steel fiber; the regulator is composed of the following raw materials in parts by weight: 35-45 parts of graphite powder, 8-15 parts of amantadine hydrochloride, and 15-25 parts of aluminum sol. The electromagnetic shielding concrete has the advantage of good electromagnetic shielding performance.

[0005] CN 105418036 B discloses an electromagnetic shielding concrete. The raw materials used include, in parts by weight: 70-80 parts of binder, 10-15 parts of carbon fiber, 8-10 parts of carbon black, 5-10 parts of mica powder, 0.5-0.8 parts of rubber powder, 0.1-0.3 parts of water reducing agent, and 0.05-0.1 parts of defoaming agent; the specific preparation method is to mix the above raw materials with aggregate, add water and stir evenly, then pour it into the framework constructed by copper foam, and polish it after curing. The obtained electromagnetic shielding concrete has good electromagnetic shielding performance and has a wide application prospect.

[0006] CN 102219447 B discloses an electromagnetic shielding concrete and a preparation method thereof. The ratio of each component is: 175-180 kg / m 3 , aggregate 1725-1760 kg / m3 , wherein the mass percentages of the components are as follows: fine aggregate 35 - 40%, coarse aggregate 60% - 65%, water - binder ratio 0.32 - 0.34, volume fraction of steel fiber 0.8% - 1.2% of the concrete volume, mass fraction of carbon fiber 0.6 - 0.8% of the mass of the cementitious material, and mass fraction of water - reducing agent 0.5 - 2.0% of the mass of the cementitious material. This electromagnetic shielding concrete can effectively shield electromagnetic radiation with frequencies ranging from 100 MHz to 1.5 GHz, can effectively utilize waste materials, has low cost, and is widely applied.

[0007] Generally speaking, the shielding materials currently used in concrete usually consist of materials such as steel fibers, carbon fibers, and graphite. By directly utilizing the electromagnetic shielding ability of such conductive materials and making a preliminary incorporation, a certain level of electromagnetic shielding ability can be achieved. However, the direction of this invention is to ensure that under the premise of limited usage of the electromagnetic shielding material and without sacrificing the strength and insulation of the concrete, the electromagnetic shielding performance is not reduced but even improved. Summary of the Invention

[0008] In view of the problems in the related art, the present invention provides a high - strength concrete and its preparation method to overcome the above - mentioned technical problems existing in the prior related art.

[0009] The technical solution of the present invention is realized as follows: An electromagnetic shielding material combination is prepared by matching surface - insulated modified conductive fibers with surface - insulated sheet - shaped electromagnetic shielding materials. When the concrete sets, foam is generated by a foaming agent and is extruded and aggregated to form a "linear + sheet - shaped" electromagnetic shielding microstructure, which is equivalent to a metamaterial absorber of "steel bar + resonant ring". Without affecting the strength of the concrete at low doping levels, the electromagnetic shielding ability and sound absorption ability of the concrete are improved.

[0010] The specific content of the invention is as follows: A high - strength concrete, the raw materials used in which, by weight, include: 70 - 80 parts of binder, 30 - 40 parts of active filler, 15 - 25 parts of surface - insulated electromagnetic shielding filler, 10 - 20 parts of foaming agent, and 1 - 3 parts of water - reducing agent.

[0011] Preferably, the binder consists of cement and water.

[0012] More preferably, the cement is one of portland cement and phosphate cement.

[0013] More preferably, the water - binder ratio of the binder is 0.5 - 0.6:1.

[0014] Preferably, the active filler consists of one or more of fly ash, ore powder, silica fume, and foam ceramic powder.

[0015] More preferably, the D50 particle size of the active filler is 5-10 μm.

[0016] More preferably, the active filler is subjected to magnetic separation to eliminate conductive ferromagnetic materials, and the conductivity of the material is less than 1*10 - 5 S / cm.

[0017] Preferably, the surface-insulated electromagnetic shielding filler is composed of surface-insulated modified conductive fibers and surface-insulated flaky electromagnetic shielding materials.

[0018] More preferably, the D50 diameter of the surface-insulated modified conductive fibers is less than 25% of the radial dimension of the surface-insulated flaky electromagnetic shielding material.

[0019] More preferably, the thickness of the surface-insulated flaky electromagnetic shielding material is less than 10% of the D50 diameter of the surface-insulated modified conductive fibers.

[0020] More preferably, the components of the electromagnetic shielding filler are: 5-10 parts of surface-insulated modified conductive fibers and 10-15 parts of surface-insulated flaky electromagnetic shielding materials.

[0021] Preferably, the surface-insulated flaky electromagnetic shielding material is one of flaky alumina and surface-insulated modified flaky conductive materials.

[0022] More preferably, the flaky conductive material of the surface-insulated modified flaky conductive material is one of flaky FeSiAl, nano-flaky nickel, nano-flaky iron, and nano-flaky magnetite.

[0023] More preferably, the D50 radial dimension of the flaky alumina is 20-60 μ, and the thickness is less than 20% of the diameter of the surface-insulated modified conductive fibers.

[0024] More preferably, the thickness is 100-500 nm.

[0025] Preferably, the conductive fiber material of the surface-insulated modified conductive fibers is one of carbon fibers and steel fibers.

[0026] More preferably, the flexural modulus of the conductive fibers is greater than 100 GPa.

[0027] More preferably, the length of the surface-insulated modified conductive fibers is 50-100 times the radial dimension of the surface-insulated flaky electromagnetic shielding material.

[0028] More preferably, the D50 length of the conductive fibers is 1-6 mm, and the diameter is 5-10 μm.

[0029] Preferably, the surface insulating functional layer material of the surface insulating electromagnetic shielding filler is one of silica, titanium dioxide or alumina.

[0030] More preferably, the surface insulating functional layer is amorphous silica.

[0031] Preferably, the foaming agent is composed of one or more of sodium dodecyl sulfate, tea saponin, alkyl polyglucoside, sodium dodecylbenzenesulfonate.

[0032] More preferably, the foaming agent is used in combination with one or more of a foam stabilizer and a dispersant.

[0033] More preferably, the foam stabilizer is composed of one or more of sodium carboxymethyl cellulose and modified silicone resin polyether emulsion.

[0034] More preferably, the dispersant is composed of one or more of monoglyceryl stearate, allyl ether ester, allyl polyethylene glycol, hexenyl bisstearamide, acrylamide, sodium methallylsulfonate.

[0035] More preferably, the amount of the foam stabilizer is 0.5 - 1.5 parts, and the amount of the dispersant is 1 - 3 parts.

[0036] Preferably, the water reducing agent is one of polycarboxylate water reducing agent, FDN water reducing agent, melamine-based water reducing agent, and amino sulfonate-based water reducing agent.

[0037] Preferably, the raw material components of the high-strength concrete further include aggregate.

[0038] More preferably, the aggregate is crushed stone with a D50 particle size of 5 - 10 mm.

[0039] More preferably, the weight ratio of the aggregate to the binder is 1.5 - 1:1.

[0040] A method for preparing the high-strength concrete includes the following steps: S1: Mix the surface insulating modified conductive fiber, the surface insulating sheet electromagnetic shielding material and the active filler according to the corresponding amounts, add them to a mixer, and stir at a speed of 400 - 450 r / min to prepare a uniformly stirred mixture A; S2: Add the cement and / or aggregate according to the amounts to the mixer, stir uniformly at a speed of 300 - 350 r / min, then add the mixture A, and stir uniformly at a speed of 450 - 550 r / min to prepare the mixture B; S3: Add the corresponding amount of water-reducing agent and water to mixture B, and stir evenly at a speed of 300 - 350 r / min; then add the corresponding amount of foaming agent and / or foam stabilizer, and stir evenly at a speed of 500 - 650 r / min to prepare mixture C. S4: Pour mixture C into a mold for molding, demold after curing, and cut into high-strength foam concrete products of the required size.

[0041] More preferably, a corresponding amount of dispersant is also added in step S2.

[0042] The method for preparing the surface-insulated modified conductive fiber is as follows: S1: Uniformly disperse 0.5 - 1 part of conductive fiber in 30 - 40 parts of absolute ethanol, add 1 - 1.5 parts of dispersant, perform ultrasonic magnetic stirring at 200 - 250 r / min for 0.5 - 3 h, and then obtain modified conductive fiber through suction filtration or centrifugal separation. S2: Add the corresponding amount of modified conductive fiber and dispersant to the solvent, stir and mix evenly, add the insulating oxide precursor solution, then transfer it to a high-pressure reactor, heat at high temperature to form a hydrothermal reaction, form an insulating coating, filter or centrifuge the precipitate, wash and dry to make the surface-insulated modified conductive fiber.

[0043] Preferably, the insulating oxide precursor is one of a silicon source, an aluminum source, and a titanium source.

[0044] More preferably, the insulating oxide is silicon dioxide, aluminum oxide, and titanium dioxide.

[0045] More preferably, the insulating oxide is amorphous silicon dioxide.

[0046] More preferably, the method for coating amorphous silicon dioxide is as follows: Add 3 - 5 parts of modified conductive fiber and 1 - 1.5 parts of dispersant to 15 - 20 parts of isopropanol, place it in a 40 °C water bath, stir and mix evenly, sequentially add 10 - 15 parts of deionized water, 0.5 - 1 part of concentrated ammonia water, 20 - 25 parts of silicon source, stir evenly at 40 °C to obtain a precursor solution, transfer the precursor solution to a high-pressure reactor, react at 120 °C for 1 h, naturally cool to room temperature, filter the precipitate, wash and dry to obtain silicon dioxide-insulated modified conductive fiber.

[0047] More preferably, the silicon source is tetraethyl orthosilicate.

[0048] Preferably, the dispersant is composed of one or several of KH550, sodium dodecylbenzenesulfonate, and sodium dodecyl sulfate.

[0049] The method for preparing the surface-insulated sheet-shaped electromagnetic shielding material is as follows: S1: Uniformly disperse 1 - 1.5 parts of the sheet-shaped electromagnetic shielding material in 40 - 50 parts of absolute ethanol, add 0.5 - 1 part of a dispersant, and perform ultrasonic magnetic stirring at 150 - 200 r / min for 0.5 - 1 h. Then, obtain the modified sheet-shaped electromagnetic shielding material through suction filtration or centrifugal separation. S2: Add the corresponding amounts of the modified sheet-shaped electromagnetic shielding material and the dispersant to a solvent, stir and mix evenly, add the insulating oxide precursor solution, then transfer it to a high-pressure reactor, heat it at a high temperature to form a hydrothermal reaction, form an insulation coating, filter or centrifuge the precipitate, wash and dry it to make the surface-insulated sheet-shaped electromagnetic shielding material.

[0050] More preferably, when the insulating oxide precursor solution is a silicon source precursor, the coating method is as follows: Add 6 - 8 parts of the modified sheet-shaped electromagnetic shielding material and 0.5 - 1 part of the dispersant to 20 - 25 parts of isopropanol, place it in a 40 °C water bath, stir and mix evenly, sequentially add 10 - 15 parts of deionized water, 0.5 - 1 part of concentrated ammonia water, and 15 - 20 parts of the silicon source, stir evenly at 40 °C to obtain a precursor solution. Transfer the precursor solution to a high-pressure reactor, react at 120 °C for 1 h, naturally cool to room temperature, filter the precipitate, wash and dry it to obtain the silica surface-insulated sheet-shaped electromagnetic shielding material.

[0051] Compared with the prior art, the beneficial effects of the present invention are as follows: The high-strength concrete prepared by the present invention constructs a "linear + sheet-shaped" electromagnetic shielding microstructure by doping an appropriate amount of one-dimensional surface-insulated modified conductive fibers and two-dimensional surface-insulated sheet-shaped electromagnetic shielding materials, achieving an efficient electromagnetic shielding effect while ensuring a relatively high volume resistivity to meet the electrical insulation requirements of concrete materials.

[0052] Furthermore, the present invention combines a foaming method to prepare foamed concrete. By foaming and expanding to squeeze and improve the concentration of local electromagnetic shielding materials, the mutual inductance and magnetic loss ability of the electromagnetic shielding microstructure are increased, further improving the electromagnetic shielding effect. At the same time, the bulk density of the material is reduced and the sound absorption coefficient of the material is increased.

[0053] Furthermore, the insulating modified carbon fiber material used in the present invention enhances the mechanical strength of the foamed concrete, which helps to improve the crack resistance of the concrete. Specific embodiments

[0054] The endpoints and any values disclosed in the scope of the present invention are not limited to the exact scope or value. These scopes or values should be understood to include values close to these scopes or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in the present invention.

[0055] Example 1, Foamed concrete of silica-insulated modified carbon fiber prepared by the present invention: S1: Uniformly disperse 1 part of short-cut carbon fiber with a diameter of Φ10μm and a length of 6mm in 40 parts of absolute ethanol, add 1 part of KH550, treat it with ultrasonic magnetic stirring at 200r / min for 1h, and filter by suction to obtain surface-modified short-cut carbon fiber; S2: Add 5 parts of modified short-cut carbon fiber and 0.5 part of dispersant to 20 parts of isopropanol, place it in a water bath at 40°C, stir and mix evenly, then add 115 parts of deionized water, 0.5 part of concentrated ammonia water, and 20 parts of tetraethyl orthosilicate in sequence, stir evenly at 40°C to obtain a precursor solution. Transfer the precursor solution into a high-pressure reactor, react at 120°C for 1h, naturally cool to room temperature, filter the precipitate by suction, wash and dry it to obtain insulated modified carbon fiber; S3: Mix 5 parts of insulated modified carbon fiber, 15 parts of flaky alumina with a radial size of 40μm and a thickness of 300nm, 20 parts of fly ash, 5 parts of ore powder, 5 parts of silicon powder, and 1 part of hexenyl bisstearamide, add them to a mixer, and stir at a speed of 450r / min to uniformly prepare mixture A; S4: Add 40 parts of portland cement and 40 parts of crushed aggregate with a D50 of 8mm according to the number of parts into the mixer, stir evenly at a speed of 350r / min, then add mixture A, and stir evenly at a speed of 450r / min to prepare mixture B; S5: Add 1 part of polycarboxylate water reducer and 20 parts of water to mixture B, and stir evenly at a speed of 350r / min; then add 14 parts of sodium dodecyl sulfate and 1 part of sodium carboxymethylcellulose, and stir evenly at a speed of 600r / min to prepare mixture C; S6: Pour mixture C into a mold for molding, demold after curing, and cut it into high-strength concrete products of the required size.

[0056] Example 2, Foamed concrete of titanium dioxide-insulated modified carbon fiber prepared by the present invention: S1: Uniformly disperse 0.5 part of short-cut carbon fiber with a D50 of Φ5μm and a length of 3mm in 30 parts of absolute ethanol, add 1 part of sodium dodecylbenzenesulfonate, treat it with ultrasonic magnetic stirring at 250r / min for 1h, and filter by suction to obtain surface-modified short-cut carbon fiber; S2: Add 5 parts of modified chopped carbon fibers, 0.5 part of KH550, 1 part of ethylene glycol amine, and 5 parts of tetrabutyl titanate into 25 parts of absolute ethanol. After heating and stirring at 40°C until the tetrabutyl titanate is dissolved, continue stirring for 60 min to obtain precursor solution C. Transfer it into an autoclave and react at 180°C for 4 h. Naturally cool to room temperature to obtain insulating modified carbon fibers. S3: Mix 8 parts of insulating modified carbon fibers, 14 parts of flaky alumina with a radial size of 30 μm and a thickness of 500 nm, 20 parts of fly ash, 5 parts of ore powder, 5 parts of silicon powder, and 1 part of hexenyl bisstearamide, and add them to a blender. Stir at a speed of 450 r / min to uniformly prepare mixture A. S4: Add 50 parts of portland cement and 60 parts of crushed aggregate with a D50 of 10 mm by parts into a blender, stir evenly at a speed of 300 r / min, then add mixture A, and stir evenly at a speed of 450 r / min to prepare mixture B. S5: Add 1 part of polycarboxylate water reducer and 25 parts of water into mixture B, and stir evenly at a speed of 350 r / min; then add 14 parts of alkyl polyglucoside and 1 part of modified silicone resin polyether emulsion, and stir evenly at a speed of 600 r / min to prepare mixture C. S6: Pour mixture C into a mold for molding, demold after curing, and cut into high-strength concrete products of the required size.

[0057] Example 3, based on the steps of Example 1, the only change is that the flaky alumina is replaced with surface-insulated flaky silicon aluminum iron. The preparation method of the surface-insulated flaky silicon aluminum iron is as follows: S1: Uniformly disperse 1.5 parts of flaky silicon aluminum iron with a radial size of 50 μm and a thickness of 800 nm in 50 parts of absolute ethanol, add 1 part of dispersant, and treat it by ultrasonic magnetic stirring at 1200 r / min for 0.5 h. Then, obtain modified flaky silicon aluminum iron through suction filtration or centrifugal separation. S2: Add 6 parts of modified flaky electromagnetic shielding material and 0.5 part of dispersant into 20 parts of isopropanol, place it in a 40°C water bath, stir and mix evenly, sequentially add 15 parts of deionized water, 1 part of concentrated ammonia water, and 20 parts of silicon source, stir evenly at 40°C to obtain a precursor solution. Transfer the precursor solution into an autoclave, react at 120°C for 1 h, naturally cool to room temperature, filter the precipitate, wash and dry to obtain silica surface-insulated flaky silicon aluminum iron.

[0058] Example 4, based on the steps of Example 1, is changed to foamed concrete without adding surface-insulated flaky electromagnetic shielding material.

[0059] Example 5, based on the steps of Example 1, is changed to foamed concrete without adding surface-insulated modified conductive fibers.

[0060] Example 6, based on the steps of Example 1, is changed to foamed concrete without adding surface-insulated electromagnetic shielding fillers.

[0061] Example 7, based on the steps of Example 1, is changed to ordinary concrete without adding foaming agents.

[0062] Example 8, based on the steps of Example 1, the D50 diameter of the added surface-insulated modified conductive fibers is greater than 50% of the radial dimension of the surface-insulated flaky electromagnetic shielding material.

[0063] Example 9, based on the steps of Example 1, the thickness of the added surface-insulated flaky electromagnetic shielding material is greater than 50% of the D50 diameter of the surface-insulated modified conductive fibers.

[0064] Example 10, based on the steps of Example 1, adds un-surface-modified conductive fibers.

[0065] Example 11, based on the steps of Example 1, adds un-surface-modified flaky metal.

[0066] Example 12, based on the steps of Example 1, adds un-surface-modified conductive fibers and flaky metal.

[0067] Example 13, based on the steps of Example 1, adds long-cut carbon fibers with a length exceeding 30 mm.

[0068] Example 14, based on the steps of Example 1, does not add aggregates.

[0069] In Examples 1 to 14, the performance parameters of the silica and titanium dioxide coating layers for the required surface insulation modification are: the prepared SiO2 is α-quartz, the surface resistivity is greater than 1*10 13 Ω·m, and the average thickness is 35 nm. The prepared TiO2 layer is anatase type, the surface resistivity is greater than 1*10 5 Ω·m, and the average thickness is 25 nm. Performance testing Specimen preparation: Pour the concrete slurries prepared in Examples 1 to 14 into a mold with dimensions of 100 mm × 100 mm × 100 mm. After molding for 24 hours, demold, and place the demolded specimens in a standard curing box at a temperature of (20 ± 2)°C and a relative humidity > 95% for 28 days.

[0070] 1. Compressive strength: The foam concrete specimens were tested in accordance with JG / T 266-2011 "Foamed Concrete". The compressive strength of the specimens cured to the age was determined using an AG-X type Shimadzu electronic universal testing machine.

[0071] 2. Electromagnetic shielding effectiveness detection: The electromagnetic shielding concrete samples were prepared into specimens with a thickness of 3.6 mm, and an Aglient HP 4291B impedance analyzer was used to scan the electromagnetic shielding transmission coefficient curve of the samples in the range of 600 MHz - 1 GHz.

[0072] 3. Sound absorption coefficient detection: The concrete cured for 28 days was cut and processed into circular specimens with dimensions of 30 mm × 30 mm, and according to the national standard GBJ 88-85 "Measurement Code for Sound Absorption Coefficient and Sound Resistance Porosity by Standing Wave Tube Method", the SW-477 standing wave tube was used to measure its sound absorption coefficient at frequencies of 500 Hz and 2000 Hz.

[0073] It can be seen from the data in Table 1 that the "wire + sheet" surface insulation electromagnetic shielding structure in Examples 1, 2, and 3 has a maximum shielding effect improvement of 1.5 times compared to that in Example 6 at 1 GHz. In Examples 4, 5, 8, 9, and 13, due to the lack of "wire" or "sheet" materials or overly large "wire" or "sheet" materials, the electromagnetic mutual inductance effect is weakened or disappears, thus reducing the electromagnetic shielding ability. In Examples 10, 11, and 12, due to the lack of surface insulation, the fibers or sheet metals form an overall conductor state, weakening the electromagnetic mutual inductance effect of the microstructure, equivalent to increasing the eddy current size on the surface of the conductive fibers, reducing the reverse magnetic field shielding ability, and at the same time, the macroscopic conductive connection caused by the overlap between conductive fibers increases the leakage risk during product use. In Example 14, due to the lack of aggregate, there is no skeleton support during the preparation of the aggregated microstructure by foam extrusion, reducing the equivalent density of the mesh holes in the microstructure, thus weakening the electromagnetic shielding ability. However, compared with the products with structural defects of "wire + sheet" in the examples, its electromagnetic shielding ability is relatively strong.

[0074] Furthermore, in the products with foam holes in the examples, the sound absorption coefficient of the concrete is significantly improved, and the sound absorption coefficient (average value of low frequency and high frequency) of the products exceeds 0.2, meeting the sound absorption material standard. Among them, in Examples 4 and 6, due to the lack of micro-nano rigid materials, the surface roughness of the holes decreases, which has a more obvious impact on the absorption of low-frequency noise.

[0075] Furthermore, due to the addition of short fibers, it is significantly helpful for improving the compressive capacity of concrete products. The improvement level of Example 1 compared to Example 6 is 27%.

[0076] Table 1 The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-strength concrete, characterized in that, Raw material composition including the following components: 70 - 80 parts of adhesive, 30 - 40 parts of active filler, 15 - 25 parts of surface-insulating electromagnetic shielding filler, 10 - 20 parts of foaming agent, 1 - 3 parts of water reducer; The surface-insulating electromagnetic shielding filler is composed of 5 - 10 parts of surface-insulating modified conductive fibers and 10 - 15 parts of surface-insulating flaky electromagnetic shielding material; The D50 diameter of the surface-insulating modified conductive fibers is less than 25% of the radial dimension of the surface-insulating flaky electromagnetic shielding material; The thickness of the surface-insulating flaky electromagnetic shielding material is less than 20% of the D50 diameter of the surface-insulating modified conductive fibers.

2. The high-strength concrete according to claim 1, wherein The surface-insulating functional layer material of the surface-insulating electromagnetic shielding filler is one of silica, titanium dioxide or alumina.

3. The high-strength concrete according to claim 1, wherein The radial dimension of the surface-insulating flaky electromagnetic shielding material is 20 - 60 μm, and the length of the surface-insulating modified conductive fibers is 50 - 100 times the radial dimension of the surface-insulating flaky electromagnetic shielding material.

4. The high-strength concrete according to claim 1, wherein The conductive fibers of the surface-insulating modified conductive fibers are one of carbon fibers or steel fibers with a flexural modulus greater than 100 GPa, and the surface-insulating flaky electromagnetic shielding material is one of flaky alumina or surface-insulating modified flaky conductive material.

5. The high-strength concrete according to claim 4, characterized in that, The flaky conductive material of the surface-insulating modified flaky conductive material is one of flaky FeSiAl, nano-flaky nickel, nano-flaky iron, or nano-flaky magnetite.

6. The high-strength concrete according to claim 1, wherein, The adhesive is composed of cement and water in a water-cement ratio of 0.5 - 0.6:

1.

7. The high-strength concrete according to claim 1, wherein The active filler includes one or more of fly ash, ore powder, silica fume, and foam ceramic powder, and the conductivity of the active filler is less than 1*10 -5 S / cm.

8. The high-strength concrete according to claim 1, characterized in that, The components of the raw materials further include one or more of a foam stabilizer and a dispersant. The foam stabilizer is 0.5 - 1.5 parts, and the dispersant is 1 - 3 parts.

9. The high-strength concrete according to claim 1, wherein The components of the raw materials further include aggregate. The aggregate is gravel with a D50 particle size of 5 - 10 mm, and the weight ratio of the aggregate to the binder is 1.5 - 1:

1.

10. A preparation method for preparing high-strength concrete, characterized in that, Including the following steps: S1: Uniformly disperse the corresponding amounts of conductive fibers or flaky metals in absolute ethanol respectively, add a dispersant, and obtain modified conductive fibers and modified flaky metals through suction filtration or centrifugal separation; S2: Add the corresponding amounts of modified conductive fibers or modified flaky metals and a dispersant to a solvent respectively, stir and mix evenly, add an insulating oxide precursor solution, and form an insulating coating through a high-pressure and high-temperature hydrothermal reaction. Filter or centrifuge the precipitate, wash and dry it to make surface-insulating modified conductive fibers and surface-insulating flaky electromagnetic shielding materials; S3: Mix the surface-insulating modified conductive fibers, surface-insulating flaky electromagnetic shielding materials and active filler according to the corresponding amounts, add them to a mixer, and stir evenly to prepare mixture A; S4: Add cement and / or aggregate according to the amounts to the mixer, stir evenly, then add mixture A, and continue to stir evenly to prepare mixture B; S5: Add the corresponding amounts of water reducer and water to mixture B, stir evenly; then add the corresponding amounts of foaming agent and / or foam stabilizer, dispersant, and continue to stir evenly to prepare mixture C; S6: Pour mixture C into a mold for molding, demold after curing, and cut it into high-strength foam concrete products of the required size.

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