Green asphalt pavement repairing material and preparation method thereof

Abstract

The application discloses a green asphalt pavement repairing material and a preparation method thereof. The green asphalt pavement repairing material is prepared from the following components in a mass fraction: modified milling material 90-110 parts; emulsified asphalt 5-6 parts; modified cashew phenol-based epoxy resin 0.6-1.2 parts; cement 10-12 parts; mineral powder 2-3 parts; water 3.8-4.6 parts; and modified silane coupling agent 0.15-0.18 parts. The application improves the combination ability of the milling material and the asphalt, significantly improves the mechanical strength and water stability of the asphalt mixture, effectively prevents the interface damage caused by the load and the dynamic water scouring, and has the advantages of green environmental protection, economic saving and recycling by selecting the bio-based material, and has the prospect of large-scale engineering application.

Description

Technical Field

[0001] This invention relates to the field of road repair material preparation technology, and in particular to a green asphalt road repair material and its preparation method. Background Technology

[0002] Most cold-mix asphalt repair materials are made from different emulsified or diluted asphalts and appropriately graded aggregates. However, ordinary emulsified asphalt has low bond strength, is brittle at low temperatures, and has a slow strength development, so the mix proportions must be specifically modified.

[0003] Epoxy resin emulsified asphalt is a composite material that has been used more and more in recent years. Epoxy resin emulsified asphalt mixtures have the advantages of high bonding strength, high shear strength and good high temperature performance. However, due to its high crosslinking density, its cured system has disadvantages such as high brittleness, poor toughness and poor impact resistance, which limits its application in road materials. It is necessary to improve and toughen epoxy resin. However, most of the toughening agents currently used are extracted from petroleum, which has the characteristics of non-renewability and high price, making it difficult to meet the requirements of modern society for ecological green, environmentally friendly and sustainable development.

[0004] With the continuous improvement of my country's road network, the roads constructed in the early stages are gradually entering the major and medium-scale repair phase. The milled material produced from milling old roads not only leads to a waste of resources but also occupies a large amount of land. The surface of the milled material is covered with the aged asphalt of the old road surface. The aromatic compounds in the asphalt gradually decrease from the outside to the inside, and the outermost layer of asphalt contains almost no aromatic compounds, forming an unfavorable structure of hard and brittle outer layer and soft inner layer, which is not conducive to the adhesion between the milled material and the new asphalt.

[0005] To address the aforementioned issues, there is an urgent need for a high-performance asphalt pavement repair material that is based on milled material, environmentally friendly, and possesses excellent properties. Summary of the Invention

[0006] The present invention aims to address the shortcomings of the prior art by providing a green asphalt pavement repair material and its preparation method.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a green asphalt pavement repair material, wherein the specific formula of the green asphalt pavement repair material, by mass fraction, comprises the following components:

[0008] 90-110 parts of modified milling material;

[0009] 5-6 parts of emulsified asphalt;

[0010] 0.6–1.2 parts of modified cashew phenol-based epoxy resin;

[0011] 10-12 parts cement;

[0012] 2-3 parts mineral powder;

[0013] Water 3.8–4.6 parts;

[0014] 0.15–0.18 parts of modified silane coupling agent;

[0015] The modified milling material is composed of milling material and corn stalk oil, and the mass ratio of milling material to corn stalk oil is 1:0.01-0.12; and the preparation process is as follows: first, the corn stalk oil and milling material are pre-stirred in a mixing pot at 150℃ and 40r / min, and then stirred for 20min at 150℃ and 90r / min to obtain the modified milling material;

[0016] The modified cashew nut phenol-based epoxy resin is composed of octaphenylaminopropyl cage-like polysilsesquioxane, tetrahydrofuran, cashew nut phenol-based epoxy resin, and epoxy curing agent, and the mass ratio of octaphenylaminopropyl cage-like polysilsesquioxane: tetrahydrofuran: cashew nut phenol-based epoxy resin: epoxy curing agent is 0.02~0.025:0.23~0.25:1:1~1.1; the preparation process is as follows: first, octaphenylaminopropyl cage-like polysilsesquioxane is added to tetrahydrofuran and stirred until completely dissolved, then cashew nut phenol-based epoxy resin is added and stirred for 20 min, then rotary evaporated at 60℃ for 30 min using a rotary evaporator, then epoxy curing agent is added, mechanically stirred for 15 min, and then placed in a curing chamber for curing to obtain the modified cashew nut phenol-based epoxy resin;

[0017] The modified silane coupling agent is composed of silane coupling agent, water, ethanol, and acetic acid, and the mass ratio of silane coupling agent:water:ethanol is 1:1:3. The preparation process is as follows: water and ethanol are mixed to obtain an ethanol aqueous solution, the silane coupling agent is placed in the ethanol aqueous solution for mixing, acetic acid is added to the mixed solution until the pH reaches 4, and the solution is allowed to stand for a period of time to obtain the modified silane coupling agent.

[0018] Specifically, the modified milling material has a nominal maximum particle size of 13.2 mm and features continuously graded, uniformly distributed particles.

[0019] Specifically, corn stalk oil contains acetic acid, hydroxyacetone, and acetaldehyde; it is a viscous liquid with a density of 0.89 g / cm³. 3 The pH value is 5.5.

[0020] Specifically, the emulsified asphalt is a slow-setting, medium-setting emulsified asphalt with a mixing time >120s and an initial setting time of 35min.

[0021] Specifically, the cashew phenolic epoxy resin is a polyglycidyl ether epoxy phenolic resin derived from cashew shell oil, with a viscosity of not less than 28,000 CPS and an epoxy equivalent of 550-580.

[0022] Specifically, the cement is composed of a mixture of silicate cement and rapid-hardening sulfoaluminate cement, with a mass ratio of silicate cement to rapid-hardening sulfoaluminate cement of 8:2; the silicate cement is of type P·O 42.5, and the rapid-hardening sulfoaluminate cement is of type R·SAC42.5.

[0023] Specifically, the mineral powder is limestone mineral powder, with a sieve pass rate of not less than 80% through a 0.075mm sieve and a hydrophilicity coefficient of less than 0.8%.

[0024] Specifically, the silane coupling agent is model KH-570, with a chromatographic purity of 98.7% and a density of 0.950 g / cm³. 3 Its refractive index is 1.426 m / s.

[0025] A method for preparing a green asphalt pavement repair material includes the following steps:

[0026] S1. Place the weighed cement, mineral powder, and modified milling material into a mixing pot and stir at low speed for 2 minutes to prepare a uniformly mixed dry material mixture A for later use.

[0027] S2. Place the weighed emulsified asphalt, modified cashew phenol-based epoxy resin, water, and modified silane coupling agent into a mixing pot and stir at low speed for 30 seconds to obtain mixture B.

[0028] S3. Continue stirring mixture B at low speed, add the pre-prepared dry mixture A, continue stirring at low speed for 30 seconds after adding dry mixture A, then stir at high speed for 120 seconds, and finally stir at low speed for 30 seconds to obtain green asphalt pavement repair material.

[0029] The beneficial effects of this invention are:

[0030] 1. This invention achieves uniform compatibility among emulsified asphalt, modified cashew nut shell epoxy resin, and cement through blending. The cured epoxy resin products can form an interwoven spatial network structure with the demulsified asphalt and cement hydration products, improving the overall adhesion and density of the structure. In the strength development process, the hydration reaction of the cementitious material, the curing reaction of the water-based epoxy resin, and the bonding of the emulsified asphalt are coordinated and unified, significantly improving the strength of the repair material. Simultaneously, the epoxy resin enhances the bonding performance between the cement hydration products and the emulsified asphalt, and the increased temperature and alkaline environment after cement hydration further promote the curing of the epoxy resin.

[0031] 2. Corn stalk oil alters the component ratio of aged asphalt on the surface of milling mix and restores the stability of the asphalt colloidal structure to a certain extent, thereby restoring the physical and rheological properties of aged asphalt and improving the integration of milling mix and emulsified asphalt.

[0032] 3. After being treated with modified silane coupling agent and cement, the milled material forms a stable structure of aged asphalt-silane coupling agent-Ca(OH)2-emulsified asphalt, which strengthens the bonding ability between the milled material and asphalt, significantly improves the mechanical strength and water stability of the asphalt pavement repair material, and effectively prevents interface damage caused by load and dynamic water erosion.

[0033] 4. Cashew phenol-based epoxy resin and corn stalk oil are both bio-based materials with the advantages of being green, environmentally friendly, economical, and recyclable, making them the best choice for raw materials for large-scale asphalt pavement maintenance. Detailed Implementation

[0034] The present invention will be further described in detail below through several embodiments. These embodiments are merely implementation solutions selected to achieve the objectives of the present invention and are not intended to limit the scope of protection of the present invention. Furthermore, the endpoint values ​​and any values ​​given in the present invention are not limited to these precise ranges or values; these ranges or values ​​should be values ​​close to these ranges or values.

[0035] The present invention will be further described below with reference to embodiments:

[0036] A green asphalt pavement repair material,

[0037] The specific formula of the green asphalt pavement repair material, by mass fraction, consists of the following components:

[0038] 90-110 parts of modified milling material;

[0039] 5-6 parts of emulsified asphalt;

[0040] 0.6–1.2 parts of modified cashew phenol-based epoxy resin;

[0041] 10-12 parts cement;

[0042] 2-3 parts mineral powder;

[0043] Water 3.8–4.6 parts;

[0044] 0.15 to 0.18 parts of modified silane coupling agent.

[0045] The modified milling material is composed of milling material and corn stalk oil, with a mass ratio of milling material to corn stalk oil of 1:0.01-0.12. The preparation process is as follows: first, the corn stalk oil and milling material are pre-stirred in a mixing tank at 150℃ and 40 r / min; then, they are stirred for 20 min at 150℃ and 90 r / min to obtain the modified milling material. The modified milling material has a nominal maximum particle size of 13.2 mm and exhibits continuous gradation and uniform particle size distribution. The corn stalk oil contains acetic acid, hydroxyacetone, and acetaldehyde, is a viscous liquid, and has a density of 0.89 g / cm³.3 The pH value is 5.5. The milled material is taken from the milled material from municipal road repairs, with an asphalt content of approximately 8.2%. Modifying the washed material with corn stalk oil offers the following advantages:

[0046] Environmental protection and resource recycling: Using corn stalk oil as a modifier is a method to transform agricultural waste into valuable industrial raw materials. This method not only reduces the environmental burden of agricultural waste but also promotes resource recycling, aligning with the principles of sustainable development.

[0047] Improved physical properties: Corn stalk oil contains certain natural resins and waxes, which can improve the physical properties of the spun yarn, such as increasing its flexibility, crack resistance, and adhesion. This means that the modified spun yarn is better able to adapt to temperature changes, reducing cracks caused by thermal expansion and contraction, while also improving the material's waterproof performance.

[0048] Improving recycling rates: The performance of asphalt modified with corn stalk oil can be significantly improved, greatly increasing the recycling rate of old asphalt materials. This not only reduces the demand for new materials and lowers production costs, but also alleviates pressure on natural resources.

[0049] Enhanced road performance: Modified washed and shoveled pavement exhibits superior road performance in practical applications, including but not limited to higher abrasion resistance, better skid resistance, and stronger fatigue resistance. These improved properties help extend pavement service life, reduce maintenance frequency, and thus save on long-term maintenance costs.

[0050] In conclusion, using corn stalk oil to modify washed and shredded materials can not only effectively improve the physical and road performance of the materials and promote the recycling of resources, but also contribute to environmental protection, making it an economical and environmentally friendly choice.

[0051] The modified cashew nut shell epoxy resin is composed of octaphenylaminopropyl cage-like polysilsesquioxane, tetrahydrofuran, cashew nut shell epoxy resin, and epoxy curing agent, with a mass ratio of octaphenylaminopropyl cage-like polysilsesquioxane: tetrahydrofuran: cashew nut shell epoxy resin: epoxy curing agent of 0.02-0.025: 0.23-0.25: 1: 1-1.1. The preparation process is as follows: first, octaphenylaminopropyl cage-like polysilsesquioxane is added to tetrahydrofuran and stirred until completely dissolved; then, cashew nut shell epoxy resin is added and stirred for 20 minutes; then, it is rotary evaporated at 60°C for 30 minutes; finally, the epoxy curing agent is added, and the mixture is mechanically stirred for 15 minutes; and then it is cured in a curing chamber to obtain the modified cashew nut shell epoxy resin. The cashew nut shell epoxy resin is a polyglycidyl ether epoxy phenolic resin derived from cashew nut shell oil, with a viscosity of not less than 28000 CPS and an epoxy equivalent of 550-580.

[0052] Ordinary epoxy resin is a common high-performance polymer with good mechanical strength, chemical resistance, and adhesive properties. In asphalt pavement repair materials, it can improve the overall strength and durability of the material. Modified cashew nut phenol-based epoxy resin is a new type of resin obtained by introducing cashew nut phenol groups into ordinary epoxy resin. This modified resin retains the advantages of ordinary epoxy resin while also possessing some unique performance advantages. Specifically:

[0053] Weather resistance: While ordinary epoxy resins have good chemical resistance, they may age after prolonged exposure to ultraviolet radiation and humid, hot environments. Modified cashew nut shell epoxy resins, with the introduction of cashew nut shell groups, significantly improve the material's weather resistance, extending its lifespan in outdoor environments and making it less prone to aging.

[0054] Flexibility: Ordinary epoxy resins are typically brittle and hard, especially at low temperatures, making them prone to cracking. Modified cashew nut shell epoxy resins: The cashew nut shell groups give the material better flexibility, allowing it to maintain good elasticity and crack resistance at low temperatures, making it suitable for road repairs under various climatic conditions.

[0055] Adhesion performance: Ordinary epoxy resins have good adhesion performance, but their adhesion to certain substrates is limited. Modified cashew nut shell epoxy resins, due to the presence of cashew nut shell groups, have stronger adhesion to a variety of substrates (such as metals, concrete, asphalt, etc.) and can better adapt to complex construction environments.

[0056] Chemical resistance: Ordinary epoxy resins already possess good chemical resistance. Modified cashew phenol-based epoxy resins further enhance chemical resistance, especially exhibiting better stability in acidic and alkaline environments, making them suitable for road repairs in special applications such as chemical plants and ports.

[0057] Environmental friendliness: Ordinary epoxy resins may cause some environmental pollution during the production process. Modified cashew nut shell epoxy resin, on the other hand, uses cashew nut shell extract from natural plants, which has good biodegradability and environmental friendliness, aligning with the development trend of green building materials.

[0058] Application Performance: Ordinary epoxy resins cure quickly, requiring application to be completed within a short time. Modified cashew phenol-based epoxy resins offer a wider application window, moderate curing speed, and easier application, improving flexibility and convenience.

[0059] In summary, modified cashew nut shell epoxy resin outperforms ordinary epoxy resin in terms of weather resistance, flexibility, adhesion, chemical resistance, environmental friendliness, and workability. These advantages make modified cashew nut shell epoxy resin an ideal choice for high-performance asphalt pavement repair materials, especially suitable for road repair projects requiring long-term durability and high reliability.

[0060] The modified silane coupling agent is composed of a silane coupling agent, water, ethanol, and acetic acid, with a mass ratio of silane coupling agent:water:ethanol of 1:1:3. Its preparation process is as follows: water and ethanol are mixed to obtain an ethanol-water solution; the silane coupling agent is then placed in the ethanol-water solution and mixed; acetic acid is added to the mixture until the pH reaches 4; the mixture is allowed to stand for a period of time to obtain the modified silane coupling agent. The silane coupling agent is designated KH-570, with a chromatographic purity of 98.7% and a density of 0.950 g / cm³. 3 Its refractive index is 1.426 m / s.

[0061] In asphalt repair materials, modified silane coupling agents offer several advantages over ordinary silane coupling agents. Through specific chemical modifications, modified silane coupling agents can better adapt to the properties of asphalt materials and the construction environment, thereby achieving significant improvements in multiple performance indicators. Specifically:

[0062] Enhancing interfacial bonding: Ordinary silane coupling agents can improve the interfacial bonding between inorganic fillers and organic polymer matrices, but the effect is limited. Modified silane coupling agents, through chemical modification, can more effectively form stable chemical bonds between inorganic fillers and organic polymers, significantly enhancing interfacial bonding and improving the overall strength and toughness of the material.

[0063] Improved weather resistance: Ordinary silane coupling agents may age when exposed to ultraviolet light and humid environments for extended periods. Modified silane coupling agents, on the other hand, exhibit better weather resistance, effectively resisting the effects of ultraviolet light and humid environments, thus extending the service life of materials.

[0064] Improved flexibility: Ordinary silane coupling agents may cause materials to become brittle and prone to cracking at low temperatures. Modified silane coupling agents, on the other hand, impart better flexibility to materials, allowing them to maintain good elasticity and crack resistance even at low temperatures, making them suitable for road repair under various climatic conditions.

[0065] Enhanced Adhesion Performance: While ordinary silane coupling agents can improve the adhesion of materials, their adhesion to certain substrates is limited. Modified silane coupling agents, on the other hand, exhibit stronger adhesion to a variety of substrates (such as metals, concrete, and asphalt) and are better suited to complex construction environments.

[0066] Improved chemical corrosion resistance: Ordinary silane coupling agents already possess good chemical corrosion resistance. Modified silane coupling agents further enhance chemical corrosion resistance, especially exhibiting better stability in acidic and alkaline environments, making them suitable for road repair in special applications such as chemical plants and ports.

[0067] Improved application performance: Ordinary silane coupling agents may exhibit uneven dispersion during application, affecting the quality of the work. Modified silane coupling agents, on the other hand, offer better dispersibility and compatibility, allowing for more uniform distribution within the material during application, thus improving ease of use and overall quality.

[0068] Improving fatigue resistance: Ordinary silane coupling agents may suffer fatigue damage under repeated loading. Modified silane coupling agents can significantly improve the fatigue resistance of materials, reduce damage caused by repeated loading, and extend the service life of pavements.

[0069] Environmental friendliness: Ordinary silane coupling agents may cause some environmental pollution during production and use. Modified silane coupling agents, on the other hand, generally have better biodegradability and environmental friendliness, which aligns with the development trend of green building materials.

[0070] In summary, modified silane coupling agents offer numerous advantages in asphalt repair materials, including enhanced interfacial bonding, improved weather resistance, improved flexibility, enhanced adhesion, improved chemical corrosion resistance, improved workability, enhanced fatigue resistance, and improved environmental friendliness. These advantages make modified silane coupling agents an ideal choice for high-performance asphalt repair materials, particularly suitable for road repair projects requiring long-term durability and high reliability.

[0071] The emulsified asphalt is a slow-setting, medium-curing type, with a mixing time >120 seconds and an initial setting time of 35 minutes. Using slow-setting, medium-curing emulsified asphalt in asphalt pavement repair materials offers several advantages, namely:

[0072] Extended construction time: Slow cracking means the emulsified asphalt will not break down rapidly after spraying or mixing, providing workers with more time to spread and compact it evenly. Medium setting time ensures the emulsified asphalt forms a stable structure within a reasonable time after construction, avoiding premature or delayed curing.

[0073] Improved construction quality: Uniform distribution and slow-cracking characteristics allow emulsified asphalt to be distributed more evenly when mixed with aggregates, improving the uniformity and density of the mixture. Better adhesion: Slow-cracking medium-setting emulsified asphalt can better penetrate the aggregate surface during demulsification, enhancing the adhesion between aggregates and improving the overall structural stability.

[0074] Adaptability to various climatic conditions: Temperature adaptability: Slow-cracking medium-setting emulsified asphalt maintains good fluidity even at lower temperatures, making it suitable for construction under different seasons and temperature conditions. Humidity adaptability: In humid environments, the slow-cracking characteristic prevents the emulsified asphalt from breaking down too quickly, ensuring construction quality and results.

[0075] Reduced early damage: Initial strength: Slow-cracking intermediate-setting emulsified asphalt exhibits high initial strength after construction, reducing early damage to newly repaired pavements caused by vehicle traffic. Crack resistance: The slow-cracking characteristic allows emulsified asphalt to gradually form a stable structure during the solidification process, reducing cracks caused by rapid curing.

[0076] Economic advantages: High material utilization rate and slow-cracking characteristics ensure full utilization of emulsified asphalt during construction, reducing waste. Low construction cost: Longer construction time and good construction performance reduce construction difficulty and the possibility of rework, thereby reducing overall construction cost.

[0077] Environmental friendliness: Low volatility; slow-cracking, medium-setting emulsified asphalt has lower volatility during construction, reducing the emission of harmful substances and making it more environmentally friendly. Recyclability: The stable structure formed after construction facilitates material recycling and reuse, meeting the requirements of sustainable development.

[0078] In conclusion, the application of slow-cracking, medium-setting emulsified asphalt in asphalt pavement repair materials not only extends construction time and improves construction quality, but also adapts to different climatic conditions, reduces early damage, and exhibits good economic and environmental benefits. These advantages make slow-cracking, medium-setting emulsified asphalt a preferred material for pavement repair projects.

[0079] The cement is a mixture of silicate cement and rapid-hardening sulfoaluminate cement, with a mass ratio of silicate cement to rapid-hardening sulfoaluminate cement of 8:2; the silicate cement grade is P·O 42.5, and the rapid-hardening sulfoaluminate cement grade is R·SAC42.5. The use of this mixture in asphalt pavement repair materials offers several advantages, namely:

[0080] Rapid hardening: Rapid-hardening sulfoaluminate cement is characterized by its rapid hardening, achieving high early strength in a short period. This allows repair materials to be used quickly after application, minimizing traffic disruption. Silicate cement, while hardening relatively slowly, offers high later-stage strength and provides long-term stability. Using a mixture of these two types of cement balances early and later-stage strength, achieving the dual advantages of rapid hardening and long-term stability.

[0081] Improved early strength: Rapid-hardening sulfoaluminate cement provides high strength in the early stages, helping to reduce the risk of deformation and damage to the repair material after application. Silicate cement continues to provide strength gain in later stages, ensuring the long-term performance of the repair material.

[0082] Enhanced durability: Silicate cement possesses excellent durability and corrosion resistance, enabling it to withstand chemical erosion and environmental factors. Rapid-hardening sulfoaluminate cement, while exhibiting high early strength, has relatively lower durability. Using a mixture of these materials can compensate for this deficiency and improve overall durability.

[0083] Improved workability: Rapid-hardening sulfoaluminate cement has good fluidity and plasticity, facilitating construction. Silicate cement has good bonding properties and stability, contributing to improved overall performance of the mixture. Using them together optimizes workability, making construction more convenient and efficient.

[0084] Adaptable to various climatic conditions: Rapid-hardening sulfoaluminate cement hardens quickly even at low temperatures, making it suitable for winter construction. Silicate cement exhibits good stability at high temperatures, making it suitable for summer construction. A mixture can be used to meet the construction needs under different climatic conditions.

[0085] Reducing shrinkage cracks: Rapid-hardening sulfoaluminate cement has a lower shrinkage rate, which can reduce cracks caused by shrinkage. Silicate cement, although having a higher shrinkage rate, has high later-stage strength, providing better overall stability. Using them together can reduce shrinkage cracks and improve the crack resistance of repair materials.

[0086] Economic efficiency: While rapid-hardening sulfoaluminate cement is more expensive, its usage is relatively low; silicate cement is relatively cheaper and used in larger quantities. Mixing these materials can balance costs and achieve a dual optimization of economics and performance.

[0087] In summary, the combined use of silicate cement and rapid-hardening sulfoaluminate cement offers numerous advantages in asphalt pavement repair materials, including rapid hardening, improved early strength, enhanced durability, improved workability, adaptability to various climatic conditions, and reduced shrinkage cracking. This mixed cement not only improves construction efficiency and repair quality but also offers good economic efficiency and practicality, making it an ideal choice for asphalt pavement repair materials.

[0088] The mineral powder is limestone mineral powder, with a passing rate of no less than 80% through a 0.075mm sieve and a hydrophilicity coefficient of less than 0.8%. Using this mineral powder has the following advantages:

[0089] Fineness advantage: The passing rate of a 0.075mm sieve is no less than 80%, which means that the mineral powder particles are very fine. Fine-grained mineral powder can better fill the voids in the mixture, improving the density and stability of the mixture. Fine particles can also increase the contact area between asphalt and aggregates, improve adhesion, and thus enhance the overall mechanical properties.

[0090] Low hydrophilicity coefficient: A hydrophilicity coefficient of less than 0.8% indicates that the mineral powder has a weaker ability to absorb water. This has several advantages: Reduced water impact: Mineral powder with a low hydrophilicity coefficient is less likely to absorb water during construction, reducing the negative impact of moisture on the performance of the mixture, especially in humid environments, maintaining the stability and workability of the mixture. Improved durability: Mineral powder with a low hydrophilicity coefficient reduces water penetration into the material, mitigating the damage to the pavement caused by freeze-thaw cycles and improving pavement durability. Enhanced adhesion: Mineral powder with a low hydrophilicity coefficient bonds more easily with asphalt, forming a more stable asphalt mastic, enhancing the cohesion and adhesion of the asphalt mixture.

[0091] Improving Mixture Performance: Fine-grained mineral powder with a low hydrophilicity coefficient enhances the high-temperature stability and low-temperature crack resistance of asphalt mixtures, reducing rutting and cracking. Improved Rheological Properties: Fine-grained mineral powder improves the rheological properties of the mixture, making it easier to pave and compact during construction, thus improving construction quality. Enhanced Anti-stripping Performance: Mineral powder with a low hydrophilicity coefficient reduces moisture erosion of the asphalt film, increases the adhesion between asphalt and aggregates, reduces asphalt film stripping, and improves the pavement's anti-stripping performance.

[0092] Environmental and economic benefits: High-fineness mineral powder with a low hydrophilicity coefficient allows for better utilization, reducing material waste and lowering construction costs. Extended service life: High-quality mineral powder improves the overall performance of road surfaces, extending their lifespan and reducing the frequency of maintenance and resurfacing, resulting in better economic efficiency.

[0093] In conclusion, using limestone powder that meets specific technical requirements (with a sieve pass rate of no less than 80% through a 0.075mm sieve and a hydrophilicity coefficient of less than 0.8%) in asphalt pavement repair materials can significantly improve the density, stability, durability, and anti-stripping properties of the mixture. These advantages not only improve construction quality but also extend the service life of the pavement, demonstrating good economic and environmental benefits.

[0094] A method for preparing a green asphalt pavement repair material includes the following steps:

[0095] S1. Place the weighed cement, mineral powder, and modified milling material into a mixing pot and stir at low speed for 2 minutes to prepare a uniformly mixed dry material mixture A for later use.

[0096] S2. Place the weighed emulsified asphalt, modified cashew phenol-based epoxy resin, water, and modified silane coupling agent into a mixing pot and stir at low speed for 30 seconds to obtain mixture B.

[0097] S3. Continue stirring mixture B at low speed, add the pre-prepared dry mixture A, continue stirring at low speed for 30 seconds after adding dry mixture A, then stir at high speed for 120 seconds, and finally stir at low speed for 30 seconds to obtain green asphalt pavement repair material.

[0098] In S2 above, emulsified asphalt provides good adhesion and plasticity, ensuring easy paving and compaction during construction. Modified cashew phenol-based epoxy resin provides excellent mechanical strength, weather resistance, chemical resistance, and flexibility. Water acts as a solvent, helping to uniformly disperse the emulsified asphalt and other components. Modified silane coupling agent enhances the interfacial bonding between inorganic fillers and organic polymers, improving the overall strength and toughness of the material. Mixing mixture B and dry mixture A creates a high-performance asphalt repair material. This material exhibits significant advantages in early strength, rapid hardening, durability, crack resistance, flexibility, adhesion, workability, fatigue resistance, and environmental friendliness, making it particularly suitable for road repair projects requiring long-term durability and high reliability.

[0099] Example 1

[0100] A green asphalt pavement repair material, wherein the specific formula of the green asphalt pavement repair material is composed of the following components by mass fraction: 100 parts modified milling material, 5 parts emulsified asphalt, 0.6 parts modified cashew phenol-based epoxy resin, 10 parts cement, 2 parts mineral powder, 3.8 parts water, and 0.16 parts modified silane coupling agent.

[0101] A method for preparing a green asphalt pavement repair material includes the following steps:

[0102] S1. Place the weighed cement, mineral powder, and modified milling material into a mixing pot and stir at low speed for 2 minutes to prepare a uniformly mixed dry material mixture A for later use.

[0103] S2. Place the weighed emulsified asphalt, modified cashew phenol-based epoxy resin, water, and modified silane coupling agent into a mixing pot and stir at low speed for 30 seconds to obtain mixture B.

[0104] S3. Continue stirring mixture B at low speed, add the pre-prepared dry mixture A, continue stirring at low speed for 30 seconds after adding dry mixture A, then stir at high speed for 120 seconds, and finally stir at low speed for 30 seconds to obtain green asphalt pavement repair material.

[0105] Example 2

[0106] A green asphalt pavement repair material, wherein the specific formula of the green asphalt pavement repair material, by mass fraction, consists of the following components: 100 parts modified milling material, 5.5 parts emulsified asphalt, 0.9 parts modified cashew phenol-based epoxy resin, 11 parts cement, 2.5 parts mineral powder, 4.2 parts water, and 0.16 parts modified silane coupling agent.

[0107] A method for preparing a green asphalt pavement repair material includes the following steps:

[0108] S1. Place the weighed cement, mineral powder, and modified milling material into a mixing pot and stir at low speed for 2 minutes to prepare a uniformly mixed dry material mixture A for later use.

[0109] S2. Place the weighed emulsified asphalt, modified cashew phenol-based epoxy resin, water, and modified silane coupling agent into a mixing pot and stir at low speed for 30 seconds to obtain mixture B.

[0110] S3. Continue stirring mixture B at low speed, add the pre-prepared dry mixture A, continue stirring at low speed for 30 seconds after adding dry mixture A, then stir at high speed for 120 seconds, and finally stir at low speed for 30 seconds to obtain green asphalt pavement repair material.

[0111] Example 3

[0112] A green asphalt pavement repair material, wherein the specific formula of the green asphalt pavement repair material is composed of the following components by mass fraction: 100 parts modified milling material, 6 parts emulsified asphalt, 1.2 parts modified cashew phenol-based epoxy resin, 12 parts cement, 3 parts mineral powder, 4.6 parts water, and 0.18 parts modified silane coupling agent.

[0113] A method for preparing a green asphalt pavement repair material includes the following steps:

[0114] S1. Place the weighed cement, mineral powder, and modified milling material into a mixing pot and stir at low speed for 2 minutes to prepare a uniformly mixed dry material mixture A for later use.

[0115] S2. Place the weighed emulsified asphalt, modified cashew phenol-based epoxy resin, water, and modified silane coupling agent into a mixing pot and stir at low speed for 30 seconds to obtain mixture B.

[0116] S3. Continue stirring mixture B at low speed, add the pre-prepared dry mixture A, continue stirring at low speed for 30 seconds after adding dry mixture A, then stir at high speed for 120 seconds, and finally stir at low speed for 30 seconds to obtain green asphalt pavement repair material.

[0117] Comparative Example 1

[0118] A green asphalt pavement repair material, wherein the specific formula of the green asphalt pavement repair material is composed of the following components by mass fraction: 100 parts milling material, 6 parts emulsified asphalt, 1.2 parts modified cashew phenol-based epoxy resin, 12 parts cement, 3 parts mineral powder, 4.6 parts water, and 0.18 parts modified silane coupling agent.

[0119] A method for preparing a green asphalt pavement repair material includes the following steps:

[0120] S1. Place the weighed cement, mineral powder, and milling material into a mixing pot and mix at low speed for 2 minutes to make a uniformly mixed dry material mixture A for later use.

[0121] S2. Place the weighed emulsified asphalt, modified cashew phenol-based epoxy resin, water, and modified silane coupling agent into a mixing pot and stir at low speed for 30 seconds to obtain mixture B.

[0122] S3. Continue stirring mixture B at low speed, add the pre-prepared dry mixture A, continue stirring at low speed for 30 seconds after adding dry mixture A, then stir at high speed for 120 seconds, and finally stir at low speed for 30 seconds to obtain green asphalt pavement repair material.

[0123] Comparative Example 2

[0124] A green asphalt pavement repair material, wherein the specific formula of the green asphalt pavement repair material is composed of the following components by mass fraction: 100 parts modified milling material, 6 parts emulsified asphalt, 12 parts cement, 3 parts mineral powder, 4.6 parts water, and 0.18 parts modified silane coupling agent.

[0125] A method for preparing a green asphalt pavement repair material includes the following steps:

[0126] S1. Place the weighed cement, mineral powder, and modified milling material into a mixing pot and stir at low speed for 2 minutes to prepare a uniformly mixed dry material mixture A for later use.

[0127] S2. Place the weighed emulsified asphalt, water, and modified silane coupling agent into a mixing pot and stir at low speed for 30 seconds to obtain mixture B.

[0128] S3. Continue stirring mixture B at low speed, add the pre-prepared dry mixture A, continue stirring at low speed for 30 seconds after adding dry mixture A, then stir at high speed for 120 seconds, and finally stir at low speed for 30 seconds to obtain green asphalt pavement repair material.

[0129] Comparative Example 3

[0130] A green asphalt pavement repair material, wherein the specific formula of the green asphalt pavement repair material, by mass fraction, consists of the following components: 100 parts modified milling material, 6 parts emulsified asphalt, 1.2 parts modified cashew phenol-based epoxy resin, 3 parts mineral powder, 4.6 parts water, and 0.18 parts modified silane coupling agent.

[0131] A method for preparing a green asphalt pavement repair material includes the following steps:

[0132] S1. Place the weighed mineral powder and modified milling material into a mixing pot and stir at low speed for 2 minutes to prepare a uniformly mixed dry material mixture A for later use.

[0133] S2. Place the weighed emulsified asphalt, modified cashew phenol-based epoxy resin, water, and modified silane coupling agent into a mixing pot and stir at low speed for 30 seconds to obtain mixture B.

[0134] S3. Continue stirring mixture B at low speed, add the pre-prepared dry mixture A, continue stirring at low speed for 30 seconds after adding dry mixture A, then stir at high speed for 120 seconds, and finally stir at low speed for 30 seconds to obtain green asphalt pavement repair material.

[0135] Comparative Example 4

[0136] A green asphalt pavement repair material, wherein the specific formula of the green asphalt pavement repair material is composed of the following components by mass fraction: 100 parts modified milling material, 6 parts emulsified asphalt, 1.2 parts modified cashew phenol-based epoxy resin, 12 parts cement, 3 parts mineral powder, and 4.6 parts water.

[0137] A method for preparing a green asphalt pavement repair material includes the following steps:

[0138] S1. Place the weighed cement, mineral powder, and modified milling material into a mixing pot and stir at low speed for 2 minutes to prepare a uniformly mixed dry material mixture A for later use.

[0139] S2. Place the weighed emulsified asphalt, modified cashew phenol-based epoxy resin, and water into a mixing pot and stir at low speed for 30 seconds to obtain mixture B.

[0140] S3. Continue stirring mixture B at low speed, add the pre-prepared dry mixture A, continue stirring at low speed for 30 seconds after adding dry mixture A, then stir at high speed for 120 seconds, and finally stir at low speed for 30 seconds to obtain green asphalt pavement repair material.

[0141] The dosage of each component of the green asphalt pavement repair material in Examples 1-3 and Comparative Examples 1-4 is shown in Table 1.

[0142] Table 1. Dosage of each component in the green asphalt pavement repair materials of Examples 1-3 and Comparative Examples 1-4

[0143]

[0144]

[0145] According to the standard asphalt pavement pothole cold patch finished material (JT / T 972-2015), the test procedure for asphalt and asphalt mixtures in highway engineering (JTG E20-2011), and the construction specification for asphalt pavement of highways (JTG F40-2004), the workability grade, breakage rate, initial Marshall stability, formed Marshall stability, and residual Marshall stability of the green asphalt pavement repair materials in Examples 1-3 and Comparative Examples 1-4 were tested respectively. The test results are shown in Table 2.

[0146] Table 2 Performance of green asphalt pavement repair materials in Examples 1-3 and Comparative Examples 1-4

[0147]

[0148] By comparing the performance results of Examples 1-3 and Comparative Examples 1-4 in Table 2, it can be found that the repair material prepared by mixing modified cashew phenol-based epoxy resin, cement, and modified silane coupling agent exhibits superior overall performance in all aspects (workability grade, breakage rate, initial Marshall stability, molding Marshall stability, and residual Marshall stability) compared to asphalt repair materials prepared by using either material alone or in combination. In particular, the addition of modified silane coupling agent to the epoxy resin, cement, and asphalt mixture forms a stable structure of aged asphalt-silane coupling agent-Ca(OH)2-emulsified asphalt, strengthening the adhesion between the components of the newly prepared mixture and enhancing the bond with the existing aged asphalt interface. This is of great significance for improving the repair effect of road potholes.

[0149] Comparing Example 3 and Comparative Example 1, it can be found that the modified milling mix can better integrate with the emulsified asphalt binder. Compared with the unmodified milling mix, the modified milling mix effectively improves the cohesion, initial strength, molding strength, and water stability of the repair material. Corn stalk oil changes the component ratio of the aged asphalt on the surface of the milling mix and restores the stability of the asphalt colloidal structure to a certain extent, thereby restoring the physical and rheological properties of the aged asphalt and improving the degree of integration between the milling mix and the emulsified asphalt. After treatment with modified silane coupling agent and cement, the milling mix forms a stable structure of aged asphalt-silane coupling agent-Ca(OH)2-emulsified asphalt, which makes the bonding ability between the milling mix and asphalt stronger, significantly improves the mechanical strength and water stability of the asphalt mixture, and effectively prevents interface damage caused by load and dynamic water erosion.

[0150] Comparing Example 3 and Comparative Example 2, it can be found that the asphalt pavement repair material prepared in Comparative Example 2 has a significantly higher damage rate and a decreased cohesion of the mixture, indicating that the modified cashew nut shell epoxy resin has a better bonding effect. By blending emulsified asphalt, modified cashew nut shell epoxy resin, and cement, uniform compatibility among these three components is achieved. The cured epoxy resin products can form an interwoven spatial network structure with the demulsified asphalt and cement hydration products, improving the overall adhesion and density of the structure. In strength development, the hydration reaction of the cementitious material, the curing reaction of the water-based epoxy resin, and the bonding of the emulsified asphalt achieve a coordinated and unified process, significantly improving the strength of the repair material. Simultaneously, the epoxy resin can enhance the bonding performance between the cement hydration products and the emulsified asphalt. The increased temperature and alkaline environment after cement hydration further promote the curing of the epoxy resin. Cashew nut shell epoxy resin and corn stalk oil are both bio-based materials with advantages of being green, environmentally friendly, economical, and recyclable, making them the ideal choice for large-scale asphalt pavement repair materials.

[0151] Comparing Example 3 and Comparative Example 3, it can be found that cement significantly affects the initial strength of asphalt pavement repair materials, resulting in rapid early strength development, which is more conducive to the early opening of the road to traffic.

[0152] Comparing Example 3 and Comparative Example 4 reveals that the asphalt pavement repair material prepared with the addition of the modified silane coupling agent exhibits a lower breakage rate. This indicates that the addition of the modified silane coupling agent improves the durability and crack resistance of the repair material. The silane coupling agent enhances the interfacial bonding force between the inorganic filler and the organic polymer matrix, thereby improving the overall strength and toughness of the material and reducing damage caused by external stress. Improved initial Marshall stability: Marshall stability is an important indicator of the asphalt mixture's resistance to rutting deformation. An improvement in initial Marshall stability means that newly paved or repaired pavements have better load-bearing capacity and rutting resistance in the early stages, which is crucial for ensuring the initial service quality of the road. Improved molding Marshall stability: This improved performance demonstrates that the modified silane coupling agent helps improve the stability of the asphalt mixture during the molding process, meaning that it can maintain high structural strength even after compaction and other treatments. This is critical for ensuring the long-term performance of the pavement. Improved Marshall Residual Stability: Marshall residual stability reflects the stability of asphalt mixtures after aging under certain conditions (such as high temperature and ultraviolet radiation). An increase in this value indicates that adding modified silane coupling agents can effectively slow down the aging process of the material and extend the service life of the pavement. In summary, adding modified silane coupling agents to asphalt pavement repair materials can not only reduce the breakage rate but also significantly improve several key performance indicators, thereby improving the quality and efficiency of pavement repair, extending the service life of roads, and potentially reducing future maintenance costs.

[0153] This invention improves the bonding ability between milling material and asphalt, significantly enhances the mechanical strength and water stability of asphalt mixtures, effectively prevents interface damage caused by loads and dynamic water erosion, and uses bio-based materials, which have the advantages of being green, environmentally friendly, economical, and recyclable, and have the potential for large-scale engineering applications.

[0154] The present invention has been described above by way of example. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any improvements made by adopting the inventive concept and technical solution of the present invention, or direct application to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A green asphalt pavement repair material, characterized in that: The specific formula of the green asphalt pavement repair material, by weight proportions, consists of the following components: 90-110 parts of modified milling material; 5-6 parts of emulsified asphalt; 0.6–1.2 parts of modified cashew phenol-based epoxy resin; 10-12 parts cement; 2-3 parts mineral powder; Water 3.8–4.6 parts; 0.15–0.18 parts of modified silane coupling agent; The modified milling material is composed of milling material and corn stalk oil, and the mass ratio of milling material to corn stalk oil is 1:0.01-0.12; and the preparation process is as follows: first, the corn stalk oil and milling material are pre-stirred in a mixing pot at 150℃ and 40r / min, and then stirred for 20min at 150℃ and 90r / min to obtain the modified milling material; The modified cashew nut phenol-based epoxy resin is composed of octaphenylaminopropyl cage-like polysilsesquioxane, tetrahydrofuran, cashew nut phenol-based epoxy resin, and epoxy curing agent, and the mass ratio of octaphenylaminopropyl cage-like polysilsesquioxane: tetrahydrofuran: cashew nut phenol-based epoxy resin: epoxy curing agent is 0.02~0.025:0.23~0.25:1:1~1.1; the preparation process is as follows: first, octaphenylaminopropyl cage-like polysilsesquioxane is added to tetrahydrofuran and stirred until completely dissolved, then cashew nut phenol-based epoxy resin is added and stirred for 20 min, then rotary evaporated at 60℃ for 30 min using a rotary evaporator, then epoxy curing agent is added, mechanically stirred for 15 min, and then placed in a curing chamber for curing to obtain the modified cashew nut phenol-based epoxy resin; The modified silane coupling agent is composed of silane coupling agent, water, ethanol, and acetic acid, and the mass ratio of silane coupling agent:water:ethanol is 1:1:

3. The preparation process is as follows: water and ethanol are mixed to obtain an ethanol aqueous solution, the silane coupling agent is placed in the ethanol aqueous solution for mixing, acetic acid is added to the mixed solution until the pH reaches 4, and the solution is allowed to stand for a period of time to obtain the modified silane coupling agent.

2. The green asphalt pavement repair material according to claim 1, characterized in that, The modified milling material has a nominal maximum particle size of 13.2 mm and has a continuous gradation and uniform particle size distribution.

3. The green asphalt pavement repair material according to claim 1, characterized in that, Corn stalk oil contains acetic acid, hydroxyacetone, and acetaldehyde. It is a viscous liquid with a density of 0.89 g / cm³. 3 The pH value is 5.

5.

4. The green asphalt pavement repair material according to claim 1, characterized in that, The emulsified asphalt is a slow-setting, medium-setting emulsified asphalt with a mixing time >120s and an initial setting time of 35min.

5. The green asphalt pavement repair material according to claim 1, characterized in that, Cashew phenolic epoxy resin is a polyglycidyl ether epoxy phenolic resin derived from cashew shell oil, with a viscosity of not less than 28,000 CPS and an epoxy equivalent of 550-580.

6. The green asphalt pavement repair material according to claim 1, characterized in that, The cement is composed of silicate cement and rapid-hardening sulfoaluminate cement, with a mass ratio of silicate cement to rapid-hardening sulfoaluminate cement of 8:2; the silicate cement is of type P·O 42.5 and the rapid-hardening sulfoaluminate cement is of type R·SAC42.

5.

7. The green asphalt pavement repair material according to claim 1, characterized in that, The mineral powder is limestone mineral powder, with a passing rate of not less than 80% through a 0.075mm sieve and a hydrophilicity coefficient of less than 0.8%.

8. The green asphalt pavement repair material according to claim 1, characterized in that, The silane coupling agent is model KH-570, with a chromatographic purity of 98.7% and a density of 0.950 g / cm³. 3 Its refractive index is 1.426 m / s.

9. A method for preparing a green asphalt pavement repair material according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Place the weighed cement, mineral powder, and modified milling material into a mixing pot and stir at low speed for 2 minutes to prepare a uniformly mixed dry material mixture A for later use. S2. Place the weighed emulsified asphalt, modified cashew phenol-based epoxy resin, water, and modified silane coupling agent into a mixing pot and stir at low speed for 30 seconds to obtain mixture B. S3. Continue stirring mixture B at low speed, add the pre-prepared dry mixture A, continue stirring at low speed for 30 seconds after adding dry mixture A, then stir at high speed for 120 seconds, and finally stir at low speed for 30 seconds to obtain green asphalt pavement repair material.

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