A green, low-carbon, high-rutting-resistance asphalt concrete and its preparation method

Abstract

The invention discloses a green, low-carbon, high-rutting-resistant asphalt concrete and a preparation method thereof, relating to the technical field of asphalt concrete. The technical solution is that RAP accounts for 30-40% of the mass of new aggregate, 53-65 parts of new aggregate, 3.2-4.1 parts of new asphalt, 4-6 parts of mineral powder, 0.3-0.4 parts of high-density oxidized polyolefin, 0.05-0.1 parts of desiccant, 0.05-0.1 parts of lead salt stabilizer, 0.05-0.1 parts of auxiliary agent, 1.5-3 parts of reactive polyurethane, 3-6 parts of polyester modifier, 0.5-2 parts of silane coupling agent, 0.1-0.5 parts of antioxidant, and 0.5-2 parts of dispersant. The present invention improves the performance of aged asphalt in RAP through the synergistic effect of high-density oxidized polyolefin and reactive polyurethane, enhances the rutting resistance of asphalt concrete, reduces VOC emissions, enhances the sustainability of materials, improves long-term durability, and extends the service life of roads.

Description

Technical Field

[0001] The present invention relates to the technical field of asphalt concrete, and in particular to a green, low-carbon, high-rutting-resistance asphalt concrete and a preparation method thereof. Background Art

[0002] With the rapid development of the global economy and the acceleration of urbanization, especially the frequent passage of heavy vehicles, the road traffic load has increased significantly. Road pavements are facing higher performance requirements, especially in high temperature environments and heavy traffic conditions. Traditional asphalt concrete pavements often experience rutting, which not only affects the service life of the road but also increases maintenance costs. In order to improve the performance and rutting resistance of asphalt concrete, researchers and engineering technicians have generally adopted asphalt modification technology. Modified asphalt can significantly improve the physical properties of asphalt by incorporating different types of functional modifiers, thereby improving the rutting resistance, aging resistance and high-temperature stability of asphalt concrete. Currently, commonly used asphalt modification methods include the use of modifiers such as polymers, rubber powder, and minerals, aiming to address the performance deficiencies of traditional asphalt. However, these modification methods usually have certain technical challenges, including the selection of modifiers, the control of dosage, and the stability of the modification effect.

[0003] Several technologies have been proposed to improve the rutting resistance of asphalt concrete. For example, patent publication number CN 102910681A uses aluminum chloride hexahydrate, waste rubber powder, and drinking water to prepare an anti-rutting agent, significantly improving the high-temperature rutting resistance of asphalt concrete. However, the large amount of waste rubber powder used and the high generation of volatile organic compounds (VOCs) not only increase the risk of environmental pollution but also negatively impact the long-term performance of asphalt concrete. Similarly, patent publication number CN 102887666A uses a trivalent iron salt, synthetic rubber, and a sulfur stabilizer to prepare an anti-rutting agent. While this method improves the rutting resistance of asphalt concrete at relatively low addition levels, its technical solution lacks consideration for environmental protection and sustainability, and in practical applications, the effectiveness and stability of the anti-rutting agent remain challenges. Furthermore, existing anti-rutting modification technologies mostly focus on improving asphalt's high-temperature resistance, often overlooking the complexity of the material system and its long-term environmental impact.

[0004] With increasing environmental awareness and resource scarcity, the reuse of recycled asphalt pavement (RAP) has become a key research direction for sustainable development. As an important recycled material, RAP offers significant economic and environmental advantages. Its widespread use can reduce reliance on natural resources and minimize waste emissions. However, RAP reuse also faces numerous technical challenges. Because RAP contains a significant amount of aged asphalt and mineral aggregate, the physical and chemical properties of these components have changed, limiting its application in high-performance road construction. In particular, when mixed with new asphalt, RAP can experience reduced viscosity, severe aging, and unstable road performance, limiting its effectiveness as a high-performance road material. Furthermore, while warm-mix asphalt applications can help lower mixing temperatures and reduce asphalt aging, they still present drawbacks such as unstable material properties and a short service life. In particular, under high-temperature and high-load conditions, the rutting resistance of the asphalt mixture still fails to meet the requirements for long-term road durability.

[0005] While current technology has made some progress in improving the rutting resistance of asphalt concrete by adding modifiers, it still faces a series of problems, including complex material systems, inappropriate modifier selection, and poor environmental friendliness. First, traditional modified asphalt mixtures typically rely on the combined use of multiple functional modifiers, and the issue of VOC emissions, which are particularly environmentally sensitive, remains unresolved. For example, the use of waste rubber powder and other organic modifiers not only increases environmental pollution but may also negatively impact the stability and long-term performance of asphalt mixtures. Second, while existing anti-rutting modifiers are somewhat effective in improving the high-temperature rutting resistance of asphalt, they do not fundamentally improve the performance of aged asphalt. With long-term use, the effectiveness of the modifiers may gradually weaken, and even asphalt performance may rebound. Furthermore, in the application of recycled asphalt, the performance and road use of RAP are limited by the aging of its raw materials and its compatibility with new materials. This results in unstable performance of RAP materials, and even when added in large proportions, it still cannot effectively guarantee high-temperature rutting resistance.

[0006] Especially when it comes to the addition of large proportions of RAP, existing technologies often require more complex material systems to solve these problems. The wide variety of modifiers and regeneration agents used increases the complexity and cost of the production process. In this process, how to balance the environmental protection, economy and high performance requirements of the materials remains a difficult problem that needs to be solved. More importantly, most of the current technical solutions rely on warm mix asphalt or other low-temperature construction technologies. Although they effectively reduce the aging rate of asphalt under high temperatures, the combined effect of these technical solutions is still not enough to fully meet the high requirements for anti-rutting, anti-aging and service life in road construction.

[0007] Given the shortcomings of existing technologies, the urgent challenge is to simplify the modification system, reduce environmental pollution, and improve the material's sustainability and long-term performance while maintaining high rutting resistance. In particular, when using recycled asphalt (RAP), the challenge is to effectively improve RAP's performance and address issues such as aging, low viscosity, and instability, thereby enhancing the long-term durability and rutting resistance of roads. Furthermore, an innovative solution is needed that can simplify the traditional complex material system while improving the overall performance of asphalt concrete, reducing its negative environmental impact, and adapting it to the requirements of heavy loads and high temperatures. Summary of the Invention

[0008] In order to achieve the above-mentioned purpose of the invention and address the above-mentioned technical problems, the present invention provides a green, low-carbon and highly rutting-resistant asphalt concrete, which is composed of the following components in mass fractions: RAP accounts for 30-40% of the mass of new aggregate, 53-65 parts of new aggregate, 3.2-4.1 parts of new asphalt, 4-6 parts of mineral powder, 0.3-0.4 parts of high-density oxidized polyolefin, 0.05-0.1 parts of desiccant, 0.05-0.1 parts of lead salt stabilizer, 0.05-0.1 parts of additive, 1.5-3 parts of reactive polyurethane, 3-6 parts of polyester modifier, 0.5-2 parts of silane coupling agent, 0.1-0.5 parts of antioxidant, and 0.5-2 parts of dispersant.

[0009] Preferably, the RAP comprises old asphalt and old aggregate in a mass ratio of 2:8-4:6, the old asphalt comprises one or more of base asphalt, SBS modified asphalt, and waste rubber powder modified asphalt; the old aggregate comprises one or more of basalt crushed stone, broken glass, and limestone crushed stone, and the RAP is screened into four particle sizes of 1-3 mm, 3-5 mm, 5-10 mm, and 10-16 mm.

[0010] Preferably, the new aggregate refers to one of basalt, limestone or diabase with particle sizes divided into four grades: 1-3 mm, 3-5 mm, 5-10 mm and 10-16 mm.

[0011] Preferably, the new asphalt is one or more of 70# matrix asphalt, 90# matrix asphalt or SBS modified asphalt.

[0012] Preferably, the high-density oxidized polyolefin is one or both of high-density oxidized polyethylene and oxidized polypropylene, with a density of 0.98-1.02 g / cm3, a viscosity of 4100-4800 cp at 150°C, a melting point of 130°C-140°C, and a molecular weight of 2000-10000 g / mol.

[0013] Preferably, the polyester modifier is one of epoxy resin and maleic anhydride modified polyester; and the silane coupling agent is one of aminosilane and vinylsilane.

[0014] Preferably, the mineral powder is limestone mineral powder, and the desiccant is one or more of silica gel, white carbon black or montmorillonite.

[0015] Preferably, the lead salt stabilizer is one or more of tribasic lead sulfate, dibasic lead phosphite or dibasic lead stearate; and the auxiliary agent is one or more of phthalates and epoxidized soybean oil.

[0016] Preferably, the antioxidant is antioxidant 1024, and the dispersant is one of polyvinyl alcohol and sodium polyacrylate.

[0017] The present invention also provides a method for preparing the green, low-carbon, and highly rutting-resistant asphalt concrete according to the above-mentioned method, comprising the following steps:

[0018] S1: RAP and new aggregate are placed in a high-energy ball mill for physical processing for 10-15 minutes to produce a microscopic rough structure on the aggregate surface. Then, a silane coupling agent is dissolved in ethanol to form a solution with a mass concentration of 1-5%, and the solution is evenly coated on the surface of RAP and new aggregate. The solution is reacted for 1-2 hours to obtain pretreated RAP and new aggregate.

[0019] S2: Mix the reactive polyurethane and epoxy resin at a temperature of 100-110°C and heat until they are molten. The mixture is reacted for 30 minutes. After the reaction is complete, high-density oxidized polyolefin is added and heated and stirred for 10-15 minutes to ensure that the polyolefin is evenly dispersed in the system to form a modifier.

[0020] S3: Add the additive, lead salt stabilizer, and mineral powder to the premix, continue heating to 130-140°C, and fully mix with the new asphalt. Then, add the antioxidant and dispersant, and stir evenly for 15 minutes until completely mixed to obtain a pretreated asphalt mixture.

[0021] S4 designs the gradation of the pretreated RAP and new aggregate, and then heats them to 130℃-135℃ respectively and mixes them. Then, a modifier is added for dry mixing. The dry mixing time is 2 minutes to ensure that the modifier is evenly coated on the aggregate surface. Then, the pretreated asphalt mixture is added at a temperature of 160℃-170℃ and wet mixed for 3 minutes to ensure that the asphalt fully penetrates into the aggregate to form a uniform mixture. The gradation type of the gradation design is any one of AC, SMA, and OGFC.

[0022] S5: Compacting is performed when the temperature of the mixture reaches 160°C-170°C.

[0023] The technical solution provided by the present invention brings beneficial effects:

[0024] Improving RAP Performance: The synergistic effect of high-density oxidized polyolefins and reactive polyurethanes can effectively improve the low viscosity and instability of aged asphalt in RAP. High-density oxidized polyolefins have excellent meltability and dispersibility, forming a uniform film at low temperatures, enhancing the asphalt mixture's rutting resistance. Reactive polyurethane reacts with asphalt components to improve its physical and chemical properties, increasing the asphalt's adhesion and high-temperature resistance. As a result, the modified RAP exhibits improved high-temperature stability and long-term durability, resolving the issues of aging, low viscosity, and unstable performance that exist in traditional RAP reuse.

[0025] Improving the anti-rutting properties of asphalt concrete: The synergistic effect of polyester modifiers and high-density oxidized polyolefins (HDPOs) enables asphalt concrete to exhibit excellent anti-rutting properties at high temperatures. Polyester modifiers enhance the high-temperature bonding properties of asphalt through chemical cross-linking. HDPOs not only enhance the adhesion of asphalt but also form a more stable dispersion structure within the asphalt mixture, significantly improving the mixture's high-temperature rutting resistance.

[0026] Reducing environmental pollution and improving material sustainability: The rational use of silane coupling agents and polyester modifiers not only improves the adhesion between asphalt and aggregate but also reduces volatile organic compound (VOC) emissions. Silane coupling agents form a chemical bonding layer on the aggregate surface, enhancing the interfacial adhesion between aggregate and asphalt, eliminating the use of traditional organic solvents and thus reducing negative environmental impacts. Furthermore, through an optimized modification system, the use of complex additives in traditional asphalt concrete is reduced, resulting in a simpler material system that aligns with green and environmentally friendly design concepts.

[0027] Improved long-term performance and durability: The combination of reactive polyurethane and silane coupling agent strengthens the material's intermolecular crosslinking structure, making asphalt concrete more resistant to aging, wear, and water damage over long-term use. Especially under high-temperature and heavy-load conditions, the modified asphalt concrete effectively maintains its original performance despite rutting, crack propagation, and other destructive factors, extending the road's service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a photo of the pavement material interface of Example 1 of the present invention;

[0029] Figure 2 This is a photo of the rutting specimen of Example 1 of the present invention;

[0030] Figure 3This is a photo of the pavement core sample of Example 1 of the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the embodiments. Of course, the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0032] Example 1

[0033] S1. Pre-treatment of RAP and new aggregate:

[0034] 40% of the new aggregate (RAP) (composed of a 35:65 mass ratio of old asphalt to old aggregate, with the old asphalt being a mixture of matrix asphalt and the old aggregate being basalt crushed stone) and 58 parts of new aggregate (basalt crushed stone with particle sizes of 1-3mm, 3-5mm, 5-10mm, and 10-16mm) were placed in a high-energy ball mill for physical processing. The milling lasted 12 minutes to create a microscopic roughness on the aggregate surface, which improved the adhesion between the aggregate and the asphalt.

[0035] The silane coupling agent (vinyl silane) was dissolved in ethanol to form a solution with a mass concentration of 3%, which was evenly coated on the surface of RAP and new aggregate. The reaction time was 1.5 hours to form a stable surface chemical bonding layer.

[0036] S2. Preparation of modifier:

[0037] Mix 2 parts of reactive polyurethane with 4.5 parts of epoxy resin at 100-110°C and heat until molten. Keep the temperature steady and allow to react for 30 minutes to ensure complete reaction.

[0038] Add 0.35 parts of high-density oxidized polyolefin, continue heating and stirring for 10 minutes to ensure that the high-density oxidized polyolefin is evenly dispersed in the reaction system to form a uniform modifier.

[0039] S3. Pre-treatment of asphalt mixture:

[0040] Add 0.1 parts of phthalate, 0.08 parts of desiccant (white carbon black), 0.08 parts of lead salt stabilizer (tribasic lead sulfate) and 5% of mineral powder (limestone mineral powder) to the premix and continue heating to 130°C to 140°C.

[0041] Mix thoroughly with 3.5% new asphalt (70# base asphalt), then add 0.3 parts of antioxidant (antioxidant 1024) and 1 part of dispersant (polyvinyl alcohol), and stir evenly for 15 minutes to ensure complete mixing to obtain a uniform pretreated asphalt mixture.

[0042] S4. Mixed asphalt concrete:

[0043] The pretreated RAP and new aggregate were graded to AC-13 and heated to 130-135°C before mixing.

[0044] Add 2 parts of modifier and dry mix for 2 minutes to ensure that the modifier is evenly coated on the aggregate surface.

[0045] Then add the pretreated asphalt mixture, control the temperature at 160℃ to 170℃, and wet mix for 3 minutes to ensure that the asphalt fully penetrates into the aggregate to form a uniform mixture.

[0046] S5. Compaction molding:

[0047] When the temperature of the mixture reaches 160°C to 170°C, the mixture is sent to the compacting equipment for compaction treatment to ensure high rutting resistance and long-term durability of the asphalt concrete.

[0048] Example 2

[0049] The preparation method was the same as that in Example 1, except that RAP accounted for 35% of the new aggregate.

[0050] Example 3

[0051] The preparation method was the same as that in Example 1, except that RAP accounted for 30% of the new aggregate.

[0052] Example 4

[0053] The same preparation method as in Example 1 was used for the preparation, except that 0.3 parts of high-density oxidized polyolefin, 3 parts of reactive polyurethane, 6 parts of polyester modifier, 2 parts of silane coupling agent,

[0054] Example 5

[0055] The same preparation method as in Example 1 was used for the preparation, except that 0.4 parts of high-density oxidized polyolefin, 1.5 parts of reactive polyurethane, 6 parts of polyester modifier, 2 parts of silane coupling agent,

[0056] Example 6

[0057] The same preparation method as in Example 1 was used for the preparation, except that 0.4 parts of high-density oxidized polyolefin, 1.5 parts of reactive polyurethane, 3 parts of polyester modifier, 0.5 parts of silane coupling agent,

[0058] Example 7

[0059] The same preparation method as in Example 1 was used for the preparation, except that 0.3 parts of high-density oxidized polyolefin, 3 parts of reactive polyurethane, 3 parts of polyester modifier, 0.5 parts of silane coupling agent,

[0060] Example 8

[0061] The preparation was carried out in the same manner as in Example 1, except that the mass ratio of the old asphalt to the old aggregate was 2:8.

[0062] Example 9

[0063] The preparation method is the same as that in Example 1, except that the mass ratio of old asphalt to old aggregate is 4:6.

[0064] Example 10

[0065] The preparation method is the same as that in Example 1, except that the old asphalt is SBS modified asphalt and the old aggregate is limestone gravel.

[0066] Example 11

[0067] The high-density oxidized polyolefin was prepared by the same preparation method as in Example 1, except that the high-density oxidized polyolefin was oxidized polypropylene, the silane coupling agent was aminosilane, the desiccant was montmorillonite, the lead salt stabilizer was dibasic lead phosphite, and the auxiliary agent was epoxidized soybean oil.

[0068] Comparative Example 1

[0069] S1. Pre-treatment of RAP and new aggregate:

[0070] 40% of the new aggregate (RAP) (composed of a 35:65 mass ratio of old asphalt to old aggregate, with the old asphalt being a mixture of matrix asphalt and the old aggregate being basalt crushed stone) and 58 parts of new aggregate (basalt crushed stone with particle sizes of 1-3mm, 3-5mm, 5-10mm, and 10-16mm) were placed in a high-energy ball mill for physical processing. The milling lasted 12 minutes to create a microscopic roughness on the aggregate surface, which improved the adhesion between the aggregate and the asphalt.

[0071] S3. Pre-treatment of asphalt mixture:

[0072] Add 0.1 parts of phthalate, 0.08 parts of desiccant (white carbon black), 0.08 parts of lead salt stabilizer (tribasic lead sulfate) and 5% of mineral powder (limestone mineral powder) to the premix and continue heating to 130°C to 140°C.

[0073] Mix thoroughly with 3.5% new asphalt (70# base asphalt), then add 0.3 parts of antioxidant (antioxidant 1024) and 1 part of dispersant (polyvinyl alcohol), and stir evenly for 15 minutes to ensure complete mixing to obtain a uniform pretreated asphalt mixture.

[0074] S4. Mixed asphalt concrete:

[0075] The pretreated RAP and new aggregate were graded to AC-13, heated to 130°C to 135°C respectively, and then mixed and dry-mixed for 2 minutes.

[0076] Then add the pretreated asphalt mixture, control the temperature at 160℃ to 170℃, and wet mix for 3 minutes to ensure that the asphalt fully penetrates into the aggregate to form a uniform mixture.

[0077] S5. Compaction molding:

[0078] When the temperature of the mixture reaches 160°C to 170°C, the mixture is sent to the compacting equipment for compaction treatment to ensure high rutting resistance and long-term durability of the asphalt concrete.

[0079] Comparative Example 2

[0080] The same preparation method as in Example 1 was used for the preparation, except that no reactive polyurethane was added.

[0081] Comparative Example 3

[0082] The same preparation method as in Example 1 was used for the preparation, except that no polyester modifier or silane coupling agent was added.

[0083] Blank control example

[0084] Weigh 90.0% of new aggregate limestone and preheat it to 160℃. After drying, pour it into the mixing pot and mix it for 90s. The mixing temperature is 160℃. Heat 5.0% of 70# asphalt to 155℃ and add it to the mixing pot and mix it for 90s. Then add 5.0% of mineral powder and mix it for 90s to obtain hot mix asphalt concrete. Then, mold it at 140℃ to obtain the specimen.

[0085] Table 1 RAP and basalt synthesis gradation scheme

[0086]

[0087] Note: The gradation meets the gradation requirements of the "Technical Specifications for Highway Asphalt Pavement Construction" (JTG F40-2004). The Marshall forming and Marshall design methods are carried out in accordance with the provisions of the "Technical Specifications for Highway Asphalt Pavement Construction" (JTG F40-2004).

[0088] Experimental test:

[0089] The road performance of the examples, comparative examples and blank control group was tested according to the Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering (JTG E20-2011).

[0090] Table 2 Road performance of the examples, comparative examples and blank control group

[0091]

[0092] 1. Road performance

[0093] Dynamic Stability: All examples demonstrated significantly better dynamic stability than the control and blank groups. This demonstrates that the modifier system employed in this invention enhances asphalt concrete's rutting resistance, effectively managing stresses under high temperatures and traffic loads and reducing rutting.

[0094] Residual stability: The residual stability of the examples was generally higher than that of the control group, demonstrating the superiority of the modified materials in improving the long-term stability and durability of asphalt concrete. The modified asphalt concrete can better maintain its physical properties during use, extending the service life of the material.

[0095] Freeze-thaw splitting strength ratio: The embodiments of the present invention perform excellently in the freeze-thaw splitting strength ratio, which is significantly higher than that of the control group. Especially in harsh environments, the modified material exhibits stronger freeze-thaw resistance, reduces the expansion of cracks caused by freeze-thaw, and improves the durability of asphalt concrete.

[0096] Flexural strain: The generally high flexural strain in the examples indicates that the modified asphalt concrete has better toughness and crack resistance. Higher flexural strain values ​​indicate that the modified asphalt concrete can deform more rapidly under external forces without breaking, improving its performance under high temperature and heavy load conditions.

[0097] 2. VOC emissions

[0098] VOC emissions: The examples showed significantly lower VOC emissions than the control group, particularly after the use of silane coupling agents and other green additives, which effectively reduced volatile organic compound emissions. In contrast, the control group and the blank control group showed higher VOC emissions, demonstrating that the modified system of the present invention can effectively reduce environmental pollution and meet green and environmentally friendly design requirements.

[0099] 3. Comparative Analysis

[0100] Compared with the control and blank groups, the examples of the present invention demonstrated significant advantages in several key performance indicators, including dynamic stability, residual stability, freeze-thaw splitting strength ratio, and flexural-tensile strain, particularly in rutting resistance, durability, and environmental performance. In particular, the examples significantly improved the performance of asphalt concrete through the rational combination of materials and modification techniques.

[0101] 4. Summary of beneficial effects

[0102] According to the combination of experimental data and technical solutions, the following are the beneficial effects of the present invention:

[0103] Improved RAP Performance: This invention utilizes the synergistic effect of high-density oxidized polyolefin and reactive polyurethane to significantly improve the low viscosity and instability of aged asphalt in RAP, enhancing its high-temperature stability and long-term durability. The modified RAP can be better integrated into asphalt concrete systems, improving the material's overall performance.

[0104] Improved anti-rutting performance of asphalt concrete: Through the synergistic effect of polyester modifiers and high-density oxidized polyolefins, asphalt concrete exhibits excellent anti-rutting performance under high-temperature conditions. This demonstrates that the present invention can effectively improve the high-temperature stability of asphalt concrete and extend the service life of roads.

[0105] Reduce environmental pollution and improve material sustainability: The rational application of silane coupling agents and polyester modifiers not only improves the adhesion between asphalt and aggregate, but also effectively reduces VOC emissions and the negative impact of volatile organic compounds on the environment, which is in line with the green and environmentally friendly design concept.

[0106] Improved long-term performance and durability: This modification technology enhances asphalt concrete's resistance to aging, abrasion, and water damage by strengthening the intermolecular cross-linking structure. This allows the modified asphalt concrete to maintain its excellent performance under high temperatures, heavy traffic, and adverse weather conditions, extending the life of the road.

[0107] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A green, low-carbon, high-rutting-resistance asphalt concrete, characterized in that: The asphalt concrete is composed of the following components by mass fraction: RAP accounting for 30-40% of the mass of new aggregate, 53-65 parts of new aggregate, 3.2-4.1 parts of new asphalt, 4-6 parts of mineral powder, 0.3-0.4 parts of high-density oxidized polyolefin, 0.05-0.1 parts of desiccant, 0.05-0.1 parts of lead salt stabilizer, 0.05-0.1 parts of additive, 1.5-3 parts of reactive polyurethane, 3-6 parts of epoxy resin, 0.5-2 parts of silane coupling agent, 0.1-0.5 parts of antioxidant, and 0.5-2 parts of dispersant. The preparation method of the green, low-carbon, high-rutting-resistance asphalt concrete comprises the following steps: S1: RAP and new aggregate are placed in a high-energy ball mill for physical processing to produce a microscopic rough structure on the aggregate surface. Then, a silane coupling agent is dissolved in ethanol to form a solution with a mass concentration of 1-5%, and the solution is evenly coated on the surface of RAP and new aggregate. The solution is reacted for 1-2 hours to obtain pretreated RAP and new aggregate. S2: Mix the reactive polyurethane and epoxy resin at a temperature of 100-110°C and heat until they are molten. The mixture is reacted for 30 minutes. After the reaction is complete, high-density oxidized polyolefin is added and heated and stirred for 10-15 minutes to ensure that the polyolefin is evenly dispersed in the system to form a modifier. S3: Add the additive, lead salt stabilizer, mineral powder, and desiccant to the premix, continue heating to 130-140°C, and fully mix with the new asphalt. Then, add the antioxidant and dispersant, and stir evenly and thoroughly to obtain a pretreated asphalt mixture. S4 designs the gradation of the pretreated RAP and new aggregate, and then heats them to 130℃-135℃ respectively and mixes them. Then, a modifier is added for dry mixing to ensure that the modifier is evenly coated on the aggregate surface. Then, the pretreated asphalt mixture is added at a temperature of 160℃-170℃ and wet mixed to ensure that the asphalt fully penetrates into the aggregate to form a uniform mixture. The gradation type of the gradation design is any one of AC, SMA, and OGFC. S5: Compacting is performed when the temperature of the mixture reaches 160°C-170°C.

2. The green, low-carbon, high-rutting-resistance asphalt concrete according to claim 1, characterized in that: The RAP contains old asphalt and old aggregate in a mass ratio of 2:8-4:

6. The old asphalt includes one or more of base asphalt, SBS modified asphalt, and waste rubber powder modified asphalt; the old aggregate includes one or more of basalt crushed stone, broken glass, and limestone crushed stone. The RAP is screened into four particle sizes of 1-3mm, 3-5mm, 5-10mm, and 10-16mm.

3. The green, low-carbon, high-rutting-resistance asphalt concrete according to claim 1, characterized in that: The new aggregate refers to one of basalt, limestone or diabase with particle sizes divided into four grades: 1-3mm, 3-5mm, 5-10mm and 10-16mm.

4. The green, low-carbon, high-rutting-resistance asphalt concrete according to claim 1, characterized in that: The new asphalt is one or more of 70# matrix asphalt, 90# matrix asphalt or SBS modified asphalt.

5. The green, low-carbon, high-rutting-resistance asphalt concrete according to claim 1, characterized in that: The high-density oxidized polyolefin is one or both of high-density oxidized polyethylene and oxidized polypropylene, and its density is 0.98-1.02 g / cm 3 , the viscosity at 150℃ is 4100-4800cp, the melting point is 130℃-140℃, and the molecular weight is 2000-10000g / mol.

6. The green, low-carbon, high-rutting-resistance asphalt concrete according to claim 1, characterized in that: The silane coupling agent is one of aminosilane and vinylsilane.

7. The green, low-carbon, high-rutting-resistance asphalt concrete according to claim 1, characterized in that: The mineral powder is limestone mineral powder, and the desiccant is one or more of silica gel, white carbon black or montmorillonite.

8. The green, low-carbon, high-rutting-resistance asphalt concrete according to claim 1, characterized in that: The lead salt stabilizer is one or more of tribasic lead sulfate, dibasic lead phosphite or dibasic lead stearate; the auxiliary agent is one or more of phthalate and epoxidized soybean oil.

9. The green, low-carbon, high-rutting-resistance asphalt concrete according to claim 1, characterized in that: The antioxidant is antioxidant 1024, and the dispersant is one of polyvinyl alcohol and sodium polyacrylate.

10. A method for preparing a green, low-carbon, high-rutting-resistance asphalt concrete according to any one of claims 1 to 9, characterized in that: Here are the steps: S1: RAP and new aggregate are placed in a high-energy ball mill for physical processing to produce a microscopic rough structure on the aggregate surface. Then, a silane coupling agent is dissolved in ethanol to form a solution with a mass concentration of 1-5%, and the solution is evenly coated on the surface of RAP and new aggregate. The solution is reacted for 1-2 hours to obtain pretreated RAP and new aggregate. S2: Mix the reactive polyurethane and epoxy resin at a temperature of 100-110°C and heat until they are molten. The mixture is reacted for 30 minutes. After the reaction is complete, high-density oxidized polyolefin is added and heated and stirred for 10-15 minutes to ensure that the polyolefin is evenly dispersed in the system to form a modifier. S3: Add the additive, lead salt stabilizer, mineral powder, and desiccant to the premix, continue heating to 130-140°C, and fully mix with the new asphalt. Then, add the antioxidant and dispersant, and stir evenly and thoroughly to obtain a pretreated asphalt mixture. S4 designs the gradation of the pretreated RAP and new aggregate, and then heats them to 130℃-135℃ respectively and mixes them. Then, a modifier is added for dry mixing to ensure that the modifier is evenly coated on the aggregate surface. Then, the pretreated asphalt mixture is added at a temperature of 160℃-170℃ and wet mixed to ensure that the asphalt fully penetrates into the aggregate to form a uniform mixture. The gradation type of the gradation design is any one of AC, SMA, and OGFC. S5: Compacting is performed when the temperature of the mixture reaches 160°C-170°C.

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