Environment-friendly high-strength asphalt concrete and preparation method thereof

Abstract

The invention belongs to the field of asphalt concrete, and particularly relates to environment-friendly high-strength asphalt concrete and a preparation method thereof. The invention provides green and environment-friendly high-strength asphalt concrete which comprises the following components in parts by weight: 25-35 parts of asphalt; 3-7 parts of carbon coated microfilament steel fiber; 2 to 6 parts of a MgAl-LDH (layered double hydroxide) basalt fiber composite material; 15 to 35 parts of silica fume; 20 to 30 parts of fly ash; 4-8 parts of a silane coupling agent; and 30-36 parts of water. Through the carbon-coated microfilament steel fiber and the MgAl-LDH basalt fiber composite material, the effects of reinforcement, grid constraint and cross section are enhanced, so that the performance of the asphalt concrete is remarkably improved, and the application range of the asphalt concrete is widened.

Description

Technical Field

[0001] The present invention belongs to the technical field of asphalt concrete, and more specifically, relates to a green and environmentally friendly high-strength asphalt concrete and a preparation method thereof. Background Art

[0002] The combined damage of various climate and environmental factors and the continuous increase in traffic volume have gradually deteriorated the service performance of asphalt pavements, and the pavement is prone to rutting, cracking, water damage and other diseases. Therefore, improving the performance of asphalt pavements and extending their service life is a goal that road workers have been committed to achieving. Using fibers to strengthen asphalt concrete is considered to be an effective means to improve the service durability of asphalt pavements.

[0003] CN119569382A discloses a modified asphalt concrete and its preparation method and application, belonging to the technical field of asphalt concrete, wherein sodium silicate, sodium hydroxide and water are stirred and mixed and then transferred to a mixer as an alkali activator, fly ash, electrolytic manganese slag, cement, modified sugarcane fiber and fine sand are added to the mixer and stirred and mixed, and internal gas is discharged by vibration, and the mixture is left to stand, demoulded and crushed to obtain geopolymer aggregate; modified asphalt, geopolymer coarse aggregate and basalt fine aggregate are stirred and mixed in proportion to obtain modified asphalt concrete; geopolymer aggregate uses electrolytic manganese slag and fly ash as main raw materials, which improves the utilization rate of waste resources, and modified sugarcane fiber is added therein, which can improve the mechanical properties of geopolymer and meet the application requirements of asphalt road aggregate. Compared with adding steel fiber and polymer fiber, sugarcane fiber is degradable, more environmentally friendly, and is conducive to the demolition and recycling of temporary asphalt roads.

[0004] CN119463518A discloses a graphene composite modified asphalt concrete material for ultra-thin overlay and a preparation method thereof, belonging to the technical field of asphalt concrete; comprising 70-85 parts of petroleum asphalt, 18-25 parts of activated rubber powder, 1.5-2.5 parts of SBS modifier, 0.15-0.25 parts of stabilizer, 0.1-0.3 parts of auxiliary agent, 0.5-1 parts of PVDF, 0.5-1 parts of modified basalt fiber, 0.6-1 parts of graphene oxide powder and 0.3-1 parts of ceramic powder; during preparation, firstly PVDF, modified basalt fiber, graphene oxide, ceramic powder and additives are mixed and dispersed evenly, and then petroleum asphalt and SBS modifier are added and fully stirred; the materials are then ground through high-temperature and high-pressure colloid grinding, and after sufficient grinding, activated rubber powder is added and ground again; finally, a stabilizer is added for development, and after the development is completed, a graphene composite modified asphalt concrete material is obtained; the concrete material has super strong oil film adhesion, as well as excellent high-temperature stability, anti-deformation, and dynamic stability, and can meet the requirements of heavy-load transportation.

[0005] CN116332567A discloses an asphalt concrete and its preparation method. An asphalt concrete includes the following raw materials in parts by weight: 10 - 25 parts of asphalt, 50 - 70 parts of coarse aggregate, 10 - 20 parts of fine aggregate, 5 - 10 parts of glass fiber, 3 - 5 parts of rubber powder, 10 - 20 parts of polyether polyol, 10 - 20 parts of isocyanate, 3 - 5 parts of chain extender, 1 - 3 parts of nano - silica, and 3 - 5 parts of montmorillonite. An asphalt concrete has excellent resilience, strength and rut - resistance performance. Polyether - type polyurethane is polymerized in the asphalt concrete system, which can combine with asphalt to form a multi - dimensional cross - linked network structure, improve the bonding force between components in the asphalt concrete system, and prompt the asphalt concrete to have excellent shear stress, strength and wear - resistance performance, reducing the rutting phenomenon of the asphalt concrete pavement under the action of traffic loads.

[0006] CN119263702A discloses a high - strength asphalt concrete and its preparation method. The asphalt concrete includes the following components in parts by weight: 18 - 24 parts of asphalt, 8 - 16 parts of cement, 80 - 100 parts of crushed stone, 20 - 30 parts of cellulose ester derivatives, 40 - 50 parts of medium sand, and 50 - 60 parts of mineral fine powder; the cellulose ester derivatives include cellulose acetate phthalate and cellulose acetate, and the weight ratio of cellulose acetate phthalate to cellulose acetate is 1:9 - 9:1. Through the above technical solution, the problem of poor mechanical properties of asphalt concrete in the related art is solved.

[0007] CN118561547A discloses a hydraulic fiber asphalt concrete with a low slope flow value and its preparation method. The hydraulic fiber asphalt concrete with a low slope flow value in the present invention is composed of the following materials in parts by weight: 34 - 43 parts of asphalt; 220 - 260 parts of coarse aggregate; 240 - 280 parts of fine aggregate; 50 - 80 parts of filler; 1 - 4 parts of fiber. It is obtained by modifying basalt fiber, preparing dry materials according to the ratio, heating the modified asphalt in an amount of the ratio to 160℃ - 170℃, and adding it to the prepared dry materials and stirring for 3 - 5 minutes. The fiber asphalt concrete in the present invention can effectively improve the high - temperature slope stability, extend the service life of the impervious layer structure, and improve its low - temperature performance, deformation adaptability and durability, providing technical support for the safety of hydraulic impervious structures.

[0008] Based on the above content, the present invention provides a green and environmentally friendly high - strength asphalt concrete, which has excellent mechanical properties by adding fillers, and broadens the application range of asphalt concrete. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to overcome the defects and deficiencies existing in the prior art, and to provide a green and environmentally friendly high-strength asphalt concrete and a preparation method thereof. The green and environmentally friendly high-strength asphalt concrete provided by the present invention comprises the following components in parts by weight: 25-35 parts of asphalt; 3-7 parts of carbon-coated microfilament steel fibers; 2-6 parts of MgAl-LDH@basalt fiber composite material; 15-35 parts of silica fume; 20-30 parts of fly ash; 4-8 parts of silane coupling agent; 30-36 parts of water. The green and environmentally friendly high-strength asphalt concrete provided by the present invention comprises the following components in parts by weight: 25-35 parts of asphalt; 3-7 parts of carbon-coated microfilament steel fibers; 2-6 parts of MgAl-LDH@basalt fiber composite material; 15-35 parts of silica fume; 20-30 parts of fly ash; 4-8 parts of silane coupling agent; 30-36 parts of water. By means of the carbon-coated microfilament steel fibers and the MgAl-LDH@basalt fiber composite material, the present invention enhances the functions of reinforcement, grid constraint and cross-section, significantly improves the performance of the asphalt concrete, and expands the application scope of the asphalt concrete.

[0010] The object of the present invention is to provide a green and environmentally friendly high-strength asphalt concrete.

[0011] Another object of the present invention is to provide a preparation method of a green and environmentally friendly high-strength asphalt concrete.

[0012] The above objects of the present invention are achieved by the following technical solutions:

[0013] A green and environmentally friendly high-strength asphalt concrete comprises the following components in parts by weight:

[0014] 25-35 parts of asphalt;

[0015] 3-7 parts of carbon-coated microfilament steel fibers;

[0016] 2-6 parts of MgAl-LDH@basalt fiber composite material;

[0017] 15-35 parts of silica fume;

[0018] 20-30 parts of fly ash;

[0019] 4-8 parts of silane coupling agent;

[0020] 30-36 parts of water.

[0021] In the present invention, in a preferred technical solution, the preparation method of the MgAl-LDH@basalt fiber composite material comprises the following steps:

[0022] (1) Add basalt fibers to nitric acid solution, stir, and then subject the acid-treated basalt fibers;

[0023] (2) Ultrasonically disperse the acid-treated basalt fibers, magnesium salt, and aluminum salt obtained in step (1) in deionized water, perform ultrasonic dispersion, then add urea, stir, and then carry out a hydrothermal reaction. Cool to room temperature, filter, wash, and dry at 70 - 90 °C for 8 - 16 h to obtain the MgAl-LDH@basalt fiber composite material.

[0024] Further, in step (1), the concentration of the nitric acid solution is 0.1 - 0.3 mol / L; the length of the basalt fibers is 1 - 5 mm; the diameter is 2 - 6 μm; the stirring time is 10 - 30 min.

[0025] Further, in step (2), the magnesium salt is at least one of magnesium nitrate, magnesium chloride, and magnesium acetate; the aluminum salt is at least one of aluminum nitrate, aluminum chloride, and aluminum acetate; the ratio of the acid-treated basalt fibers, magnesium salt, aluminum salt, and urea is 100 g : 1 mol : 1 - 3 mol : 18 - 22 mol.

[0026] Further, in step (2), the ultrasonic dispersion time is 20 - 40 min; the stirring time is 10 - 30 min; the conditions of the hydrothermal reaction are hydrothermal reaction at 120 - 140 °C for 4 - 10 h; the drying is drying at 70 - 90 °C for 8 - 16 h.

[0027] In the present invention, a further preferred technical solution, the preparation method of the carbon-coated microfilament steel fiber includes the following steps:

[0028] (1) Add the microfilament steel fiber to the nitric acid solution, stir, and then obtain the acid-treated microfilament steel fiber;

[0029] (2) Disperse the acid-treated microfilament steel fiber and glucose obtained in step (1) in deionized water, stir, and then carry out a hydrothermal reaction. Cool to room temperature, filter, wash, and dry to obtain the carbon-coated microfilament steel fiber.

[0030] Further, in step (1), the concentration of the nitric acid solution is 0.1 - 0.3 mol / L; the length of the microfilament steel fiber is 15 - 25 mm, the diameter is 0.1 - 0.5 mm; the stirring time is 5 - 15 min.

[0031] Further, in step (1), the stirring time is 20 - 30 min; the mass ratio of the acid-treated microfilament steel fiber and glucose is 100 : 15 - 25; the hydrothermal conditions are hydrothermal reaction at 160 - 200 °C for 4 - 8 h; the drying is drying at 70 - 90 °C for 10 - 20 h.

[0032] In the present invention, a more preferred solution is that the particle size of the silica fume is 5 - 25 μm; the particle size of the fly ash is 0.4 - 0.8 mm; the silane coupling agent is at least one of KH-550, KH-560, and KH-570.

[0033] Based on the above-mentioned preparation method of a green and environmentally friendly high-strength asphalt concrete, the preparation method includes the following steps:

[0034] (1) Mix carbon-coated microfilament steel fibers, MgAl-LDH@basalt fiber composites, silica fume, fly ash, silane coupling agent, and water, heat to 65 - 75 °C and stir for 2 - 4 h; then add asphalt, and then raise the temperature to 150 - 190 °C and stir for 1 - 3 h to obtain high-strength asphalt concrete.

[0035] The present invention has the following beneficial effects:

[0036] In the present invention, through carbon-coated microfilament steel fibers and MgAl-LDH@basalt fiber composites, the advantages of the composites are combined, enabling them to play a good bridging role in asphalt concrete and also being able to provide good grid restraint, thereby promoting the improvement of the performance of asphalt concrete. Specific embodiments

[0037] The following specific examples are used to further illustrate the present invention, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the technical field.

[0038] Unless otherwise specified, the reagents and materials used in the following examples are all commercially available.

[0039] Example 1

[0040] A green and environmentally friendly high-strength asphalt concrete, by weight, includes the following components:

[0041] Asphalt 30 parts; the asphalt selected is 70# base asphalt;

[0042] Carbon-coated microfilament steel fibers 5 parts;

[0043] MgAl-LDH@basalt fiber composites 4 parts;

[0044] Silica fume 25 parts; the particle size of the silica fume is 15 μm;

[0045] Fly ash 25 parts; the particle size of the fly ash is 0.6 mm;

[0046] Silane coupling agent 6 parts; the silane coupling agent is KH-560;

[0047] Water 34 parts.

[0048] The preparation method of the MgAl-LDH@basalt fiber composite material comprises the following steps:

[0049] (1) Add 100 g of basalt fibers to 120 mL of a nitric acid solution with a concentration of 0.2 mol / L, stir for 20 min, and then the acid-treated basalt fibers; the length of the basalt fibers is 3 mm; the diameter is 4 μm;

[0050] (2) Ultrasonically disperse 100 g of the acid-treated basalt fibers obtained in step (1), 1 mol of magnesium nitrate, and 2 mol of aluminum chloride into 200 mL of deionized water, ultrasonically disperse for 30 min, then add 20 mol of urea, stir for 20 min, and then carry out a hydrothermal reaction at 130 °C for 8 h, cool to room temperature, filter, wash, and dry at 80 °C for 12 h to obtain the MgAl-LDH@basalt fiber composite material.

[0051] The preparation method of the carbon-coated microfilament steel fiber comprises the following steps:

[0052] (1) Add 50 g of microfilament steel fibers to 100 mL of a nitric acid solution with a concentration of 0.2 mol / L, stir for 10 min, and then the acid-treated microfilament steel fibers; the length of the microfilament steel fibers is 20 mm, and the diameter is 0.3 mm;

[0053] (2) Disperse 100 g of the acid-treated microfilament steel fibers obtained in step (1) and 20 g of glucose into 150 mL of deionized water, stir for 25 min, and then carry out a hydrothermal reaction at 180 °C for 6 h, cool to room temperature, filter, wash, and dry at 80 °C for 16 h to obtain the carbon-coated microfilament steel fiber.

[0054] A preparation method of a green and environmentally friendly high-strength asphalt concrete comprises the following steps:

[0055] (1) Mix the carbon-coated microfilament steel fiber, MgAl-LDH@basalt fiber composite material, silica fume, fly ash, silane coupling agent, and water, heat to 70 °C and stir for 3 h; then add asphalt, and then raise the temperature to 170 °C and stir for 2 h to obtain the high-strength asphalt concrete.

[0056] Example 2

[0057] A green and environmentally friendly high-strength asphalt concrete, by weight, comprises the following components:

[0058] 25 - 35 parts of asphalt; the asphalt is selected as 70# base asphalt;

[0059] 7 parts of carbon-coated microfilament steel fiber;

[0060] 2 parts of MgAl-LDH@basalt fiber composite;

[0061] 35 parts of silica fume; the particle size of the silica fume is 25 μm;

[0062] 20 parts of fly ash; the particle size of the fly ash is 0.4 mm;

[0063] 8 parts of silane coupling agent; the silane coupling agent is KH-550;

[0064] 30 parts of water.

[0065] The preparation method of the MgAl-LDH@basalt fiber composite includes the following steps:

[0066] (1) Add 100 g of basalt fiber to 120 mL of nitric acid solution with a concentration of 0.2 mol / L, stir for 20 min, and then the acid-treated basalt fiber; the length of the basalt fiber is 5 mm; the diameter is 6 μm;

[0067] (2) Ultrasonically disperse 100 g of the acid-treated basalt fiber obtained in step (1), 1 mol of magnesium chloride and 3 mol of aluminum acetate into 200 mL of deionized water, ultrasonically disperse for 40 min, then add 22 mol of urea, stir for 10 min, and then carry out hydrothermal reaction at 140 °C for 4 h, cool to room temperature, filter, wash, and dry at 90 °C for 8 h to obtain MgAl-LDH@basalt fiber composite.

[0068] The preparation method of the carbon-coated microfilament steel fiber includes the following steps:

[0069] (1) Add 50 g of microfilament steel fiber to 100 mL of nitric acid solution with a concentration of 0.2 mol / L, stir for 10 min, and then the acid-treated microfilament steel fiber; the length of the microfilament steel fiber is 15 mm, and the diameter is 0.1 mm;

[0070] (2) Disperse 100 g of the acid-treated microfilament steel fiber obtained in step (1) and 25 g of glucose into 150 mL of deionized water, stir for 30 min, and then carry out hydrothermal reaction at 200 °C for 4 h, cool to room temperature, filter, wash, and dry at 90 °C for 10 h to obtain carbon-coated microfilament steel fiber.

[0071] The preparation method of a green and environmentally friendly high-strength asphalt concrete is the same as the preparation process of Example 1.

[0072] Example 3

[0073] A green and environmentally friendly high-strength asphalt concrete, by weight, includes the following components:

[0074] 25 parts of asphalt; the asphalt selected is 70# base asphalt;

[0075] 7 parts of carbon-coated microfilament steel fibers;

[0076] 2 parts of MgAl-LDH@basalt fiber composite material;

[0077] 35 parts of silica fume; the particle size of the silica fume is 25 μm;

[0078] 20 parts of fly ash; the particle size of the fly ash is 0.4 mm;

[0079] 8 parts of silane coupling agent; the silane coupling agent is KH-570;

[0080] 30 parts of water.

[0081] The preparation method of the MgAl-LDH@basalt fiber composite material includes the following steps:

[0082] (1) Add 100 g of basalt fibers to 120 mL of nitric acid solution with a concentration of 0.2 mol / L, stir for 20 min, and then the acid-treated basalt fibers; the length of the basalt fibers is 1 mm; the diameter is 2 μm;

[0083] (2) Ultrasonically disperse 100 g of the acid-treated basalt fibers obtained in step (1), 1 mol of magnesium acetate, and 1 mol of aluminum nitrate into 200 mL of deionized water, ultrasonically disperse for 20 min, then add 18 mol of urea, stir for 30 min, and then carry out a hydrothermal reaction at 120 °C for 10 h, cool to room temperature, filter, wash, and dry at 70 °C for 16 h to obtain the MgAl-LDH@basalt fiber composite material.

[0084] The preparation method of the carbon-coated microfilament steel fibers includes the following steps:

[0085] (1) Add 50 g of microfilament steel fibers to 100 mL of nitric acid solution with a concentration of 0.2 mol / L, stir for 10 min, and then the acid-treated microfilament steel fibers; the length of the microfilament steel fibers is 25 mm, and the diameter is 0.5 mm;

[0086] (2) Disperse 100 g of the acid-treated microfilament steel fibers obtained in step (1) and 15 g of glucose into 150 mL of deionized water, stir for 20 min, and then carry out a hydrothermal reaction at 160 °C for 8 h, cool to room temperature, filter, wash, and dry at 70 °C for 20 h to obtain the carbon-coated microfilament steel fibers.

[0087] The preparation method of a green and environmentally friendly high-strength asphalt concrete is the same as the preparation process of Example 1.

[0088] Comparative Example 1

[0089] Use an equal amount of microfilament steel fibers to replace the carbon-coated microfilament steel fibers. Other conditions are the same as in Example 1. The preparation method of the microfilament steel fibers includes the following steps:

[0090] Add 50 g of microfilament steel fibers to 100 mL of nitric acid solution with a concentration of 0.2 mol / L, stir for 10 min, and then obtain the acid-treated microfilament steel fibers; the length of the microfilament steel fibers is 20 mm, and the diameter is 0.3 mm.

[0091] Comparative Example 2

[0092] Use an equal amount of basalt fibers to replace the MgAl-LDH@basalt fiber composite material. Other conditions are the same as in Example 1. The preparation method of the basalt fiber composite material includes the following steps:

[0093] Add 100 g of basalt fibers to 120 mL of nitric acid solution with a concentration of 0.2 mol / L, stir for 20 min, and then obtain the acid-treated basalt fibers; the length of the basalt fibers is 3 mm; the diameter is 4 μm.

[0094] Comparative Example 3

[0095] Use an equal amount of MgAl-LDH and basalt fiber composite material to replace the MgAl-LDH@basalt fiber composite material. Other conditions are the same as in Example 1. The preparation method of the MgAl-LDH and basalt fiber composite material includes the following steps:

[0096] (1) Add 100 g of basalt fibers to 120 mL of nitric acid solution with a concentration of 0.2 mol / L, stir for 20 min, and then obtain the acid-treated basalt fibers; the length of the basalt fibers is 3 mm; the diameter is 4 μm;

[0097] (2) Ultrasonically disperse 1 mol of magnesium nitrate and 2 mol of aluminum chloride in 200 mL of deionized water, ultrasonically disperse for 30 min, then add 20 mol of urea, stir for 20 min, and then carry out a hydrothermal reaction at 130 °C for 8 h, cool to room temperature, filter, wash, and dry at 80 °C for 12 h to obtain MgAl-LDH;

[0098] (3) Mix 100 g of the acid-treated basalt fibers obtained in step (1) and the MgAl-LDH obtained in step (2) by simple stirring to obtain the MgAl-LDH and basalt fiber composite material.

[0099] Comparative Example 4

[0100] Use an equal amount of MgAl-LDH@basalt fiber composite material to replace the carbon-coated microfilament steel fibers. Other conditions are the same as in Example 1.

[0101] Test the properties of the asphalt concrete prepared in Test Examples 1-3 and Comparative Examples 1-4. The specific test results are shown in Table 1.

[0102] Among them, the mechanical properties were tested according to the GB / T50784-2013 standard.

[0103] Table 1:

[0104] Compressive strength (MPa) Flexural strength (MPa) Example 1 106.4 93.5 Example 2 103.9 92.1 Example 3 105.1 92.4 Comparative Example 1 100.2 88.5 Comparative Example 2 98.9 87.2 Comparative Example 3 102.8 90.6 Comparative Example 4 95.9 84.2

[0105] It can be seen from Table 1 that through the comparison between the examples and the comparative examples, it can be seen that the carbon-coated microfilament steel fibers and MgAl-LDH@basalt fiber composites prepared by hydrothermal treatment in the present invention can significantly improve the mechanical properties of asphalt concrete, with the highest compressive strength of 106.4 MPa and the highest flexural strength of 93.5 MPa. It can be seen that the green and high-strength asphalt concrete prepared in the present invention has high strength and excellent mechanical properties.

[0106] The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A green and environmentally friendly high-strength asphalt concrete, characterized by: By weight, it includes the following components: Asphalt 25-35 parts; 3-7 parts of carbon-coated microfilament steel fiber; MgAl-LDH@basalt fiber composite material 2 to 6 parts; 15-35 parts of silica fume; 20-30 parts of fly ash; Silane coupling agent 4-8 parts; 30-36 parts of water.

2. The green and environmentally friendly high-strength asphalt concrete according to claim 1, characterized in that: The preparation method of the MgAl-LDH@basalt fiber composite material comprises the following steps: (1) adding basalt fiber to a nitric acid solution, stirring, and then treating the basalt fiber with acid; (2) ultrasonically dispersing the acid-treated basalt fiber, magnesium salt and aluminum salt obtained in step (1) into deionized water, then adding urea, stirring, and then performing a hydrothermal reaction, cooling to room temperature, filtering, washing, and drying at 70 to 90° C. for 8 to 16 hours to obtain a MgAl-LDH@basalt fiber composite material.

3. The green and environmentally friendly high-strength asphalt concrete according to claim 2 is characterized by: In step (1), the concentration of the nitric acid solution is 0.1-0.3 mol / L; the length of the basalt fiber is 1-5 mm; the diameter is 2-6 μm; and the stirring time is 10-30 min.

4. The green and environmentally friendly high-strength asphalt concrete according to claim 2 is characterized by: In step (2), the magnesium salt is at least one of magnesium nitrate, magnesium chloride, and magnesium acetate; the aluminum salt is at least one of aluminum nitrate, aluminum chloride, and aluminum acetate; the ratio of the acid-treated basalt fiber, magnesium salt, aluminum salt, and urea is 100 g: 1 mol; 1-3 mol: 18-22 mol.

5. The green and environmentally friendly high-strength asphalt concrete according to claim 2 is characterized by: In step (2), the ultrasonic dispersion time is 20 to 40 minutes; the stirring time is 10 to 30 minutes; the hydrothermal reaction is carried out at 120 to 140° C. for 4 to 10 hours; and the drying is carried out at 70 to 90° C. for 8 to 16 hours.

6. The green and environmentally friendly high-strength asphalt concrete according to claim 1, characterized in that: The method for preparing the carbon-coated microfilament steel fiber comprises the following steps: (1) adding microfilament steel fibers to a nitric acid solution, stirring, and then acid-treating the microfilament steel fibers; (2) dispersing the acid-treated microfilament steel fibers obtained in step (1) and glucose into deionized water, stirring, and then subjecting the mixture to a hydrothermal reaction, cooling the mixture to room temperature, filtering, washing, and drying the mixture to obtain carbon-coated microfilament steel fibers.

7. A green and environmentally friendly high-strength asphalt concrete according to claim 6, characterized in that: In step (1), the concentration of the nitric acid solution is 0.1-0.3 mol / L; the length of the microfilament steel fiber is 15-25 mm, and the diameter is 0.1-0.5 mm; and the stirring time is 5-15 min.

8. The green and environmentally friendly high-strength asphalt concrete according to claim 6, characterized in that: In step (1), the stirring time is 20 to 30 minutes; the mass ratio of the acid-treated microfilament steel fiber to glucose is 100:15 to 25; the hydrothermal condition is a hydrothermal reaction at 160 to 200° C. for 4 to 8 hours; and the drying is drying at 70 to 90° C. for 10 to 20 hours.

9. The green and environmentally friendly high-strength asphalt concrete according to claim 1, characterized in that: The particle size of the silica fume is 5 to 25 μm; the particle size of the fly ash is 0.4 to 0.8 mm; and the silane coupling agent is at least one of KH-550, KH-560 and KH-570.

10. A method for preparing green and environmentally friendly high-strength asphalt concrete according to any one of claims 1 to 9, characterized in that: The preparation method comprises the following steps: (1) Carbon-coated microfilament steel fiber, MgAl-LDH@basalt fiber composite material, silica fume, fly ash, silane coupling agent and water were mixed, heated to 65-75°C and stirred for 2-4 hours; then asphalt was added, and then the temperature was raised to 150-190°C and stirred for 1-3 hours to obtain high-strength asphalt concrete.