Three-dimensional graphene reinforced concrete and preparation method thereof

Abstract

The invention relates to the technical field of building concrete, in particular to three-dimensional graphene reinforced concrete and a preparation method thereof, and the three-dimensional graphene reinforced concrete comprises the following components: 325-480 parts of coal gangue, 242-328 parts of sand, 48-75 parts of fly ash, 5-11 parts of gypsum, 110-186 parts of Portland cement, 8-16 parts of slaked lime, 6-20 parts of a water reducing agent, 5-18 parts of modified three-dimensional graphene and 210-290 parts of water. According to the concrete added with the modified three-dimensional graphene, the overall strength of the concrete can be effectively improved, meanwhile, the modified three-dimensional graphene is uniformly dispersed in a concrete material, and the conductivity and strength of the concrete can be further improved.

Description

Technical Field

[0001] The invention relates to the technical field of building concrete, in particular to a three-dimensional graphene reinforced concrete and a preparation method thereof. Background Art

[0002] In recent years, the construction of roads, bridges, dams and high-rise buildings has been booming. Concrete has been widely used in various engineering construction projects due to its high cost-effectiveness, wide range of material sources, superior comprehensive physical properties and flexible design according to engineering needs.

[0003] With the increasing demand for concrete applications, especially in some special or harsh environments, higher requirements are placed on the overall performance and durability of concrete structures. Modern concrete not only has to bear its own weight, but also needs to withstand wind loads, earthquake loads, vehicle loads and other loads. Therefore, research and development of high-performance concrete has become particularly critical, which can not only improve the safety and reliability of the project, but also is an important way to promote the sustainable development of the construction industry.

[0004] Adding graphene to concrete is one of the development directions of modern high-performance concrete. Graphene has many properties, such as being able to enhance the strength of concrete. For example, graphene can make concrete conductive due to its unique conductive properties. The advantage of conductive concrete is that it can respond to and transmit electrical signals, which enables the concrete structure to self-monitor and detect internal damage and environmental changes in a timely manner. However, ordinary graphene has stability due to π-π bonds and van der Waals forces, but at the same time, it also causes them to tend to agglomerate and stack, limiting their application in concrete.

[0005] To this end, in response to the problems raised in the above background technology, those skilled in the art have proposed a three-dimensional graphene-reinforced concrete based on three-dimensional graphene, combined with polypyrrole and modified silica fume. Summary of the invention

[0006] The object of the present invention is to provide a three-dimensional graphene reinforced concrete and a preparation method thereof to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions: A three-dimensional graphene reinforced concrete, comprising the following components: 325-480 parts of coal gangue, 242-328 parts of sand, 48-75 parts of fly ash, 5-11 parts of gypsum, 110-186 parts of Portland cement, 8-16 parts of slaked lime, 6-20 parts of water reducer, 5-18 parts of modified three-dimensional graphene and 210-290 parts of water; The modified three-dimensional graphene comprises modified silica fume, graphene oxide and pyrrole, and the specific preparation method thereof comprises the following steps: S101, dispersing graphene oxide in a mixed solution of propanol and deionized water, then adding hydrazine hydrate, and hydrothermally reacting for 12-24 hours at a reaction temperature of 170-220° C. to obtain a three-dimensional graphene hydrogel after the reaction is completed; S102, adding ethanol solution of pyrrole to the three-dimensional graphene hydrogel in step S101, blending for 1-2 hours, and then adding ferric chloride, continuing hydrothermal reaction for 6-8 hours, the reaction temperature is 160-240° C., to obtain a three-dimensional graphene-polypyrrole hydrogel; S103, heat treating the three-dimensional graphene-polypyrrole hydrogel obtained in step S102 for 2-4 hours under an argon atmosphere at a temperature of 450-600° C. to obtain a three-dimensional graphene-polypyrrole aerogel; S104, dispersing the modified silica fume into deionized water, adding sodium benzenesulfonate, and then adding the three-dimensional graphene-polypyrrole aerogel obtained in step S103, passing nitrogen into the deionized water, stirring and mixing for 12-18 hours, and then filtering, washing with deionized water and drying the filtered product at low temperature to obtain modified three-dimensional graphene; The preparation method of the modified silica fume comprises the following steps: S201, ball-milling the silica fume with a high-energy ball mill to prepare silica fume with a particle size of less than 10 nm; S202, calcining the silicon ash after ball milling in step S201 at a high temperature of 600-800°C, and keeping the temperature for 4-6 hours before cooling to room temperature; S203, adding γ-glycidyloxypropyltrimethoxysilane to a mixed solution of ethanol and deionized water, and then adding the calcined and cooled silica fume, mixing and stirring for 10-16 hours, and then filtering and washing with deionized water to obtain modified silica fume.

[0008] Furthermore, in step S101, the mass ratio of graphene oxide, hydrazine hydrate, propanol and deionized water is 1:(1-3):(20-30):(25-40).

[0009] Furthermore, in the step S102, the mass ratio of pyrrole to ethanol in the ethanol solution of pyrrole is 1:10, and the mass ratio of ferric chloride to the ethanol solution of pyrrole is 1:(6-15).

[0010] Furthermore, the mass ratio between the graphene oxide in step S101 and the ethanol solution of pyrrole in step S102 is 1:(30-50).

[0011] Furthermore, the mass ratio of the modified silica fume, sodium benzenesulfonate and deionized water in step S104 to the ethanol solution of pyrrole in step S102 is 1:(6-8):(50-80):(35-45).

[0012] Furthermore, in step S203, the mass ratio of γ-glycidyloxypropyltrimethoxysilane, the calcined and cooled silica fume, ethanol and deionized water is 1:(0.5-2):(30-40):(30-40).

[0013] A method for preparing the above three-dimensional graphene reinforced concrete, characterized in that it comprises the following steps: S1. crushing and grinding the gangue and sand respectively, so that the particle size of the gangue is in the range of 10-30 mm, and the particle size of the sand is in the range of 1-5 mm; S2. Put the modified three-dimensional graphene into water, stir and mix evenly, then add coal gangue, sand, fly ash, gypsum, silicate cement, slaked lime and water reducing agent in sequence, continue to stir and mix evenly to obtain three-dimensional graphene reinforced concrete.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The composition of the present invention includes common solid wastes such as coal gangue, fly ash, gypsum, etc., which can be used as resources to effectively reduce environmental pressure; 2. The present invention can improve the overall strength and electrical conductivity of concrete by adding three-dimensional graphene, and the addition of polypyrrole and modified silica fume further improves the strength of concrete; 3. The combination of modified silica fume and polypyrrole in the present invention is conducive to the dispersion of three-dimensional graphene in the concrete system. The prepared concrete is uniformly conductive, and the uniformly distributed three-dimensional graphene can further improve the strength of the concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a process flow chart for preparing three-dimensional graphene reinforced concrete in the present invention; Figure 2 The process flow chart of preparing modified three-dimensional graphene in the present invention; Figure 3 The present invention is a process flow chart for preparing modified silica fume. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] See also Figures 1 to 3 , the present invention provides: A three-dimensional graphene-reinforced concrete, comprising the following components: Coal gangue, sand, fly ash, gypsum, Portland cement, slaked lime, water reducing agent, modified three-dimensional graphene and water; Among them, coal gangue, fly ash and gypsum are common solid wastes. By utilizing these solid wastes, the pressure of environmental protection is effectively reduced, and the resource utilization of solid wastes is realized at the same time; The present invention involves using modified three-dimensional graphene as an additive for concrete. Ordinary graphene is endowed with stability due to π-π bonds and van der Waals forces, but at the same time, it also causes them to tend to agglomerate and stack, limiting their application in concrete. Three-dimensional graphene has a large specific surface area, low density, high conductivity and excellent electrochemical stability, and is more suitable for application in concrete than ordinary graphene. Specifically, the modified three-dimensional graphene of the present invention is prepared by the following steps: S101, dispersing graphene oxide in a mixed solution of propanol and deionized water, then adding hydrazine hydrate, and performing a hydrothermal reaction to obtain a three-dimensional graphene hydrogel by using hydrazine hydrate as a reducing agent; S102, adding an ethanol solution of pyrrole to the three-dimensional graphene hydrogel in step S101, adding ferric chloride, and continuing the hydrothermal reaction to obtain a three-dimensional graphene-polypyrrole hydrogel. Here, since the three-dimensional graphene hydrogel is formed, it has a larger specific surface area and is more suitable for pyrrole to bind. Through the oxidation of ferric chloride, uniform polypyrrole is formed on the surface of the three-dimensional graphene hydrogel. Polypyrrole, as a conductive material, can further improve the conductive properties of the three-dimensional graphene. S103, heat-treating the three-dimensional graphene-polypyrrole hydrogel obtained in step S102 under an argon atmosphere to obtain a three-dimensional graphene-polypyrrole aerogel, wherein the three-dimensional graphene-polypyrrole aerogel obtained at this time has a uniform distribution of polypyrrole on the surface and has a huge specific surface area; S104, dispersing the modified silica fume into deionized water, adding sodium benzenesulfonate, and then adding three-dimensional graphene-polypyrrole aerogel, introducing nitrogen into the deionized water, stirring and mixing for 12-18 hours, and then filtering, washing with deionized water and drying the filtered product at low temperature to obtain modified three-dimensional graphene. At this time, the three-dimensional graphene serves as a substrate for enhancing the strength and conductivity of concrete, and at the same time serves as a carrier to uniformly load polypyrrole. Through the reaction of step S104, the polypyrrole is combined with the modified silica fume. The modified silica fume is subjected to grinding, calcination and other treatments, and its main component is highly active nano-silicon dioxide. The high activity of the modified silica fume undergoes a volcanic ash reaction and improves the strength of the concrete. The hydrophilicity of the surface also helps the three-dimensional graphene to be evenly dispersed in the entire concrete system. Its combination with polypyrrole can further improve the conductivity and strength of the entire material.

[0018] Specifically, the present invention prepares concrete doped with three-dimensional graphene through the following four embodiments: Example 1 A three-dimensional graphene reinforced concrete, comprising the following components: 400g coal gangue, 260g sand, 64g fly ash, 10g gypsum, 125g Portland cement, 9g slaked lime, 16g water reducer, 12g modified three-dimensional graphene and 245g water; The preparation method comprises the following steps: S1. crushing and grinding the gangue and sand respectively, so that the particle size of the gangue is in the range of 20 mm, and the particle size of the sand is in the range of 5 mm; S2, putting the modified three-dimensional graphene into water, stirring and mixing evenly, then adding coal gangue, sand, fly ash, gypsum, silicate cement, slaked lime and water reducing agent in sequence, and continuing to stir and mix evenly to obtain three-dimensional graphene reinforced concrete; The modified three-dimensional graphene comprises modified silica fume, graphene oxide and pyrrole, and the specific preparation method thereof comprises the following steps: S101, dispersing 16 g of graphene oxide into a mixed solution of 400 g of propanol and 450 g of deionized water, then adding 30 g of hydrazine hydrate, and hydrothermally reacting for 18 h at a reaction temperature of 180° C. to obtain a three-dimensional graphene hydrogel after the reaction is completed; S102, adding 640 g of pyrrole ethanol solution to the three-dimensional graphene hydrogel in step S101, wherein the mass ratio of pyrrole to ethanol is 1:10, and blending for 1.5 h, then adding 65 g of ferric chloride, and continuing the hydrothermal reaction for 7 h at a reaction temperature of 200° C. to obtain a three-dimensional graphene-polypyrrole hydrogel; S103, heat treating the three-dimensional graphene-polypyrrole hydrogel obtained in step S102 for 3.5 hours under an argon atmosphere at a heat treatment temperature of 550° C. to obtain a three-dimensional graphene-polypyrrole aerogel; S104, dispersing 15 g of modified silica fume into 1060 g of deionized water, adding 102 g of sodium benzenesulfonate, and then adding the three-dimensional graphene-polypyrrole aerogel obtained in step S103, passing nitrogen into the deionized water, stirring and mixing for 16 hours, and then filtering, washing with deionized water and drying the filtered product at low temperature to obtain modified three-dimensional graphene; The preparation method of the modified silica fume comprises the following steps: S201, ball-milling the silica fume with a high-energy ball mill to prepare silica fume with a particle size of 10 nm; S202, calcining the silicon ash after ball milling in step S201 at a high temperature of 750° C., keeping the temperature for 4.5 hours and then cooling to room temperature; S203, adding 20 g of γ-glycidyloxypropyltrimethoxysilane to a mixed solution of 700 g of ethanol and 650 g of deionized water, and then adding 22 g of calcined and cooled silica fume, mixing and stirring for 15 hours, filtering and washing with deionized water to obtain modified silica fume.

[0019] Example 2 A three-dimensional graphene reinforced concrete, comprising the following components: 325g coal gangue, 242g sand, 48g fly ash, 5g gypsum, 110g Portland cement, 8g slaked lime, 6g water reducer, 5g modified three-dimensional graphene and 210g water; The preparation method comprises the following steps: S1. crushing and grinding the gangue and sand respectively, so that the particle size of the gangue is in the range of 30 mm and the particle size of the sand is in the range of 1 mm; S2, putting the modified three-dimensional graphene into water, stirring and mixing evenly, then adding coal gangue, sand, fly ash, gypsum, silicate cement, slaked lime and water reducing agent in sequence, and continuing to stir and mix evenly to obtain three-dimensional graphene reinforced concrete; The modified three-dimensional graphene comprises modified silica fume, graphene oxide and pyrrole, and the specific preparation method thereof comprises the following steps: S101, dispersing 10 g of graphene oxide into a mixed solution of 200 g of propanol and 250 g of deionized water, then adding 10 g of hydrazine hydrate, and hydrothermally reacting for 12 h at a reaction temperature of 170° C. to obtain a three-dimensional graphene hydrogel after the reaction is completed; S102, adding 300 g of pyrrole ethanol solution to the three-dimensional graphene hydrogel in step S101, wherein the mass ratio of pyrrole to ethanol is 1:10, and blending for 1 hour, then adding 50 g of ferric chloride, and continuing the hydrothermal reaction for 6 hours at a reaction temperature of 160° C. to obtain a three-dimensional graphene-polypyrrole hydrogel; S103, heat treating the three-dimensional graphene-polypyrrole hydrogel obtained in step S102 for 2 hours under an argon atmosphere at a heat treatment temperature of 450° C. to obtain a three-dimensional graphene-polypyrrole aerogel; S104, dispersing 8.6 g of modified silica fume into 428 g of deionized water, adding 52 g of sodium benzenesulfonate, and then adding the three-dimensional graphene-polypyrrole aerogel obtained in step S103, passing nitrogen into the deionized water, stirring and mixing for 12 hours, and then filtering, washing with deionized water and drying the filtered product at low temperature to obtain modified three-dimensional graphene; The preparation method of the modified silica fume comprises the following steps: S201, ball-milling the silica fume with a high-energy ball mill to prepare silica fume with a particle size of 5 nm; S202, calcining the silicon ash after ball milling in step S201 at a high temperature of 600° C., and keeping the temperature for 4 hours before cooling to room temperature; S203, adding 24 g of γ-glycidyloxypropyltrimethoxysilane to a mixed solution of 360 g of ethanol and 360 g of deionized water, and then adding 12 g of calcined and cooled silica fume, mixing and stirring for 16 hours, and then filtering and washing with deionized water to obtain modified silica fume.

[0020] Example 3 A three-dimensional graphene reinforced concrete, comprising the following components: 480g of coal gangue, 328g of sand, 75g of fly ash, 11g of gypsum, 186g of Portland cement, 16g of slaked lime, 20g of water reducer, 18g of modified three-dimensional graphene and 290g of water; The preparation method comprises the following steps: S1. crushing and grinding the gangue and sand respectively, so that the particle size of the gangue is in the range of 10 mm, and the particle size of the sand is in the range of 2 mm; S2, putting the modified three-dimensional graphene into water, stirring and mixing evenly, then adding coal gangue, sand, fly ash, gypsum, silicate cement, slaked lime and water reducing agent in sequence, and continuing to stir and mix evenly to obtain three-dimensional graphene reinforced concrete; The modified three-dimensional graphene comprises modified silica fume, graphene oxide and pyrrole, and the specific preparation method thereof comprises the following steps: S101, dispersing 25 g of graphene oxide into a mixed solution of 750 g of propanol and 1000 g of deionized water, then adding 75 g of hydrazine hydrate, and hydrothermally reacting for 24 h at a reaction temperature of 220° C. to obtain a three-dimensional graphene hydrogel after the reaction is completed; S102, adding 1250 g of pyrrole ethanol solution to the three-dimensional graphene hydrogel in step S101, wherein the mass ratio of pyrrole to ethanol is 1:10, and blending for 2 h, then adding 83 g of ferric chloride, and continuing the hydrothermal reaction for 8 h at a reaction temperature of 240° C. to obtain a three-dimensional graphene-polypyrrole hydrogel; S103, heat treating the three-dimensional graphene-polypyrrole hydrogel obtained in step S102 for 4 hours under an argon atmosphere at a heat treatment temperature of 600° C. to obtain a three-dimensional graphene-polypyrrole aerogel; S104, dispersing 28 g of modified silica fume into 2240 g of deionized water, adding 224 g of sodium benzenesulfonate, and then adding the three-dimensional graphene-polypyrrole aerogel obtained in step S103, passing nitrogen into the deionized water, stirring and mixing for 18 hours, and then filtering, washing with deionized water and drying the filtered product at low temperature to obtain modified three-dimensional graphene; The preparation method of the modified silica fume comprises the following steps: S201, ball-milling the silica fume with a high-energy ball mill to prepare silica fume with a particle size of 10 nm; S202, calcining the silicon ash after ball milling in step S201 at a high temperature of 800° C., and keeping the temperature for 6 hours before cooling to room temperature; S203, adding 13 g of γ-glycidyloxypropyltrimethoxysilane to a mixed solution of 520 g of ethanol and 520 g of deionized water, and then adding 36 g of calcined and cooled silica fume, mixing and stirring for 16 hours, and then filtering and washing with deionized water to obtain modified silica fume.

[0021] Example 4 A three-dimensional graphene reinforced concrete, comprising the following components: 390g of coal gangue, 300g of sand, 65g of fly ash, 8g of gypsum, 170g of Portland cement, 10g of slaked lime, 15g of water reducing agent, 14g of modified three-dimensional graphene and 280g of water; The preparation method comprises the following steps: S1. crushing and grinding the gangue and sand respectively, so that the particle size of the gangue is in the range of 20 mm, and the particle size of the sand is in the range of 5 mm; S2, putting the modified three-dimensional graphene into water, stirring and mixing evenly, then adding coal gangue, sand, fly ash, gypsum, silicate cement, slaked lime and water reducing agent in sequence, and continuing to stir and mix evenly to obtain three-dimensional graphene reinforced concrete; The modified three-dimensional graphene comprises modified silica fume, graphene oxide and pyrrole, and the specific preparation method thereof comprises the following steps: S101, dispersing 20 g of graphene oxide into a mixed solution of 500 g of propanol and 700 g of deionized water, then adding 40 g of hydrazine hydrate, and hydrothermally reacting for 17 h at a reaction temperature of 200° C. to obtain a three-dimensional graphene hydrogel after the reaction is completed; S102, adding 800 g of ethanol solution of pyrrole to the three-dimensional graphene hydrogel in step S101, wherein the mass ratio of pyrrole to ethanol is 1:10, and blending for 2 h, then adding 75 g of ferric chloride, and continuing the hydrothermal reaction for 7 h at a reaction temperature of 220° C. to obtain a three-dimensional graphene-polypyrrole hydrogel; S103, heat treating the three-dimensional graphene-polypyrrole hydrogel obtained in step S102 for 3 hours under an argon atmosphere at a heat treatment temperature of 600° C. to obtain a three-dimensional graphene-polypyrrole aerogel; S104, dispersing 20 g of modified silica fume into 900 g of deionized water, adding 130 g of sodium benzenesulfonate, and then adding the three-dimensional graphene-polypyrrole aerogel obtained in step S103, passing nitrogen into the deionized water, stirring and mixing for 15 hours, and then filtering, washing with deionized water and drying the filtered product at low temperature to obtain modified three-dimensional graphene; The preparation method of the modified silica fume comprises the following steps: S201, ball-milling the silica fume with a high-energy ball mill to prepare silica fume with a particle size of 10 nm; S202, calcining the silicon ash after ball milling in step S201 at a high temperature of 800° C., and keeping the temperature for 6 hours before cooling to room temperature; S203, adding 30 g of γ-glycidyloxypropyltrimethoxysilane to a mixed solution of 1000 g of ethanol and 1000 g of deionized water, and then adding 26 g of calcined and cooled silica fume, mixing and stirring for 13 hours, and then filtering and washing with deionized water to obtain modified silica fume.

[0022] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that step S102 is omitted, thereby eliminating the addition of pyrrole, and the remaining steps are exactly the same as those of Example 1.

[0023] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that step S104 is completely omitted, thereby eliminating the addition of modified silica fume, and the remaining steps are exactly the same as those of Example 1.

[0024] Comparative Example 3 The difference between Comparative Example 3 and Comparative Example 1 is that step S104 is completely omitted, the addition of modified silica fume is cancelled, and the remaining steps are exactly the same as those of Comparative Example 1.

[0025] Seven groups of concrete were prepared by the above-mentioned Examples 1-4 and Comparative Examples 1-3 for 28d compressive strength test and resistivity test. The compressive strength test standard complies with GB / T50081-2002, and the data in Tables 1 and 2 are obtained. The resistivity is measured by the four-probe method. Table 1: 28d compressive strength test table of concrete prepared in Examples 1-4 and Comparative Examples 1-3 It can be clearly seen from the data of Example 1 and Comparative Examples 1-3 in Table 1 above that the strength of concrete can be significantly improved after adding polypyrrole and modified silica fume in the present invention; In addition, the concrete prepared in Examples 1-4 and Comparative Examples 1-3 were divided into three parts, and the resistivity thereof was tested in MΩ·cm using a four-probe method. The test data are shown in Table 2 below: It can be seen from the data of Example 1 and Comparative Examples 1-2 in Table 2 above that the average resistivity of Comparative Examples 1-2 is higher than that of Example 1, proving that the synthesis of polypyrrole and the addition of modified silica fume can improve the conductivity of concrete. It can be seen from the data of Example 1 and Comparative Examples 2-3 that after the addition of modified silica fume is cancelled, not only the average resistivity increases, but also the degree of dispersion of each data relative to the average value is greater, proving that the three-dimensional graphene in Comparative Examples 2-3 is unevenly distributed relative to Example 1, and the dispersion effect is reduced.

[0026] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A three-dimensional graphene reinforced concrete, characterized in that: Includes the following components: 325-480 parts of coal gangue, 242-328 parts of sand, 48-75 parts of fly ash, 5-11 parts of gypsum, 110-186 parts of Portland cement, 8-16 parts of slaked lime, 6-20 parts of water reducer, 5-18 parts of modified three-dimensional graphene and 210-290 parts of water; The modified three-dimensional graphene comprises modified silica fume, graphene oxide and pyrrole, and the specific preparation method thereof comprises the following steps: S101, dispersing graphene oxide in a mixed solution of propanol and deionized water, then adding hydrazine hydrate, and hydrothermally reacting for 12-24 hours at a reaction temperature of 170-220° C. to obtain a three-dimensional graphene hydrogel after the reaction is completed; S102, adding ethanol solution of pyrrole to the three-dimensional graphene hydrogel in step S101, blending for 1-2 hours, and then adding ferric chloride, continuing hydrothermal reaction for 6-8 hours, the reaction temperature is 160-240° C., to obtain a three-dimensional graphene-polypyrrole hydrogel; S103, heat treating the three-dimensional graphene-polypyrrole hydrogel obtained in step S102 for 2-4 hours under an argon atmosphere at a temperature of 450-600° C. to obtain a three-dimensional graphene-polypyrrole aerogel; S104, dispersing the modified silica fume into deionized water, adding sodium benzenesulfonate, and then adding the three-dimensional graphene-polypyrrole aerogel obtained in step S103, passing nitrogen into the deionized water, stirring and mixing for 12-18 hours, and then filtering, washing with deionized water and drying the filtered product at low temperature to obtain modified three-dimensional graphene; Wherein, the preparation method of the modified silica fume comprises the following steps: S201, ball-milling the silica fume with a high-energy ball mill to prepare silica fume with a particle size of less than 10 nm; S202, calcining the silicon ash after ball milling in step S201 at a high temperature of 600-800°C, and keeping the temperature for 4-6 hours before cooling to room temperature; S203, adding γ-glycidyloxypropyltrimethoxysilane to a mixed solution of ethanol and deionized water, and then adding the calcined and cooled silica fume, mixing and stirring for 10-16 hours, and then filtering and washing with deionized water to obtain modified silica fume.

2. The three-dimensional graphene reinforced concrete according to claim 1, characterized in that: In the step S101, the mass ratio of graphene oxide, hydrazine hydrate, propanol and deionized water is 1:(1-3):(20-30):(25-40).

3. The three-dimensional graphene reinforced concrete according to claim 1, characterized in that: In the step S102, the mass ratio of pyrrole to ethanol in the ethanol solution of pyrrole is 1:10, and the mass ratio of ferric chloride to the ethanol solution of pyrrole is 1:(6-15).

4. The three-dimensional graphene reinforced concrete according to claim 1, characterized in that: The mass ratio between the graphene oxide in step S101 and the ethanol solution of pyrrole in step S102 is 1:(30-50).

5. The three-dimensional graphene reinforced concrete according to claim 1, characterized in that: The mass ratio of the modified silica fume, sodium benzenesulfonate and deionized water in step S104 to the ethanol solution of pyrrole in step S102 is 1:(6-8):(50-80):(35-45).

6. The three-dimensional graphene reinforced concrete according to claim 1, characterized in that: In the step S203, the mass ratio of γ-glycidyloxypropyltrimethoxysilane, the calcined and cooled silica fume, ethanol and deionized water is 1:(0.5-2):(30-40):(30-40).

7. A method for preparing three-dimensional graphene reinforced concrete according to any one of claims 1 to 6, characterized in that: The steps include: S1. crushing and grinding the gangue and sand respectively, so that the particle size of the gangue is in the range of 10-30 mm, and the particle size of the sand is in the range of 1-5 mm; S2. Put the modified three-dimensional graphene into water, stir and mix evenly, then add coal gangue, sand, fly ash, gypsum, silicate cement, slaked lime and water reducing agent in sequence, continue to stir and mix evenly to obtain three-dimensional graphene reinforced concrete.

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