High-viscosity asphalt concrete material and preparation method thereof

Abstract

The invention provides a high-viscosity asphalt concrete material and a preparation method thereof. The asphalt concrete material is prepared from the following raw materials in parts by weight: 6 to 10 parts of nano montmorillonite / SBR (Styrene Butadiene Rubber) composite modified asphalt, 50 to 60 parts of coarse aggregate, 20 to 30 parts of fine aggregate, 5 to 10 parts of acrylic resin, 4 to 8 parts of filler, 1.0 to 1.5 parts of reinforced fiber and 0.5 to 1.0 part of modified self-repairing bio-based asphalt. The SBR is inserted into the interlayer of the nano-montmorillonite, the layered structure of the nano-montmorillonite provides attachment points for the SBR, a stable intercalation composite structure is formed, stress can be effectively dispersed and transmitted, and the local stress concentration phenomenon is reduced. By adding the modified self-repairing bio-based asphalt, aromatic ring structures contained in the modified self-repairing bio-based asphalt attract each other and are stacked together through an n-n stacking effect, so that a structure with certain strength and stability is formed. And the n-n stacking effect is a reversible interaction, so that the dynamic repair of the microcracks is realized, and the fatigue strength, the freeze-thaw splitting strength and the Marshall residual stability of the asphalt concrete material are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of asphalt concrete, and in particular to a high-viscosity asphalt concrete material and a preparation method thereof. Background Art

[0002] Asphalt concrete, commonly known as asphalt concrete, is a composite material composed of asphalt, aggregate, and filler. Asphalt concrete offers numerous advantages. First, it possesses excellent mechanical and road performance, resulting in smooth, seamless pavements that absorb shock and sound, enhancing driving comfort. Second, it is easy to construct and maintain. Construction is fast, allowing for quick completion with minimal impact on traffic. Maintenance is also simple, allowing for quick repair of localized damage and rapid restoration to service. Finally, asphalt concrete is environmentally friendly, allowing for recycling and reuse of used materials, reducing resource waste and environmental impact. Asphalt concrete is widely used not only in transportation infrastructure such as highways and urban roads, but also in airport runways, parking lots, industrial areas, and sports fields. In short, due to its excellent performance and wide application, asphalt concrete has become an indispensable material in modern engineering construction. However, existing asphalt concrete pavements are subject to long-term erosion by rainwater, which can lead to water penetration, causing the asphalt to separate from the aggregate, resulting in loose pavement and potholes. Summary of the Invention

[0003] In view of this, the present invention proposes a high-viscosity asphalt concrete material and a preparation method thereof to solve the above problems.

[0004] The technical solution of the present invention is achieved as follows:

[0005] A high-viscosity asphalt concrete material comprises the following raw materials in parts by weight: 6-10 parts of nano-montmorillonite / SBR composite modified asphalt, 50-60 parts of coarse aggregate, 20-30 parts of fine aggregate, 5-10 parts of acrylic resin, 4-8 parts of filler, 1.0-1.5 parts of reinforcing fiber, and 0.5-1.0 part of modified self-repairing bio-based asphalt.

[0006] Furthermore, a nano-montmorillonite / SBR composite modified asphalt is prepared by the following method: nano-montmorillonite with a particle size of 100-300 nm and an interlayer spacing of 1-3 nm is selected and dispersed in deionized water to prepare a nano-montmorillonite suspension. The nano-montmorillonite to deionized water ratio (g / mL) is 1:2-4. Hexadecyltrimethylammonium bromide is added to the nano-montmorillonite suspension, wherein the mass-to-volume ratio (g / mL) of hexadecyltrimethylammonium bromide to nano-montmorillonite suspension is 1.0-1.5:40-50. The mixture is stirred at 60-80°C for 2-4 hours, the solids are filtered out, and the mixture is washed 2-3 times with deionized water. The mixture is then dried at 80-100°C for 10-15 hours to prepare an activated layered nano-montmorillonite for later use. SBR latex is diluted with deionized water to a solid content of 10-20%, and sodium lauryl sulfate is added and stirred uniformly, wherein the mass volume ratio of the sodium lauryl sulfate added to the diluted SBR latex is (0.4-0.6): (90-100) g / mL to obtain a pretreated SBR latex for standby use. Activated layered nano-montmorillonite is dispersed in toluene and ultrasonically treated for 25-35 minutes to form an activated layered nano-montmorillonite suspension, wherein the mass volume ratio of the activated layered nano-montmorillonite to toluene is 1: (3-5) g / mL, and then the pretreated SBR latex is slowly added to the activated layered nano-montmorillonite suspension, wherein the volume ratio of the pretreated SBR latex to the activated layered nano-montmorillonite suspension is (1.5-2.5): (0.8-1.2), and stirred at 60-80° C. for 2-4 hours to obtain a nano-montmorillonite / SBR intercalation composite material for standby use. Heat 70# or 90# base asphalt to 160-180°C to melt it. Then, slowly add the nano-montmorillonite / SBR intercalation composite to the molten asphalt and place it in a high-speed shearing machine. The mass ratio of nano-montmorillonite / SBR intercalation composite to asphalt is (0.5-1.5):(8-12). Stir at a speed of 3000-5000 rpm for 30-60 minutes to obtain Mixture I. Sulfur is added to Mixture I, and stirring is continued for 10-20 minutes. Cool to room temperature to obtain the nano-montmorillonite / SBR composite modified asphalt, which is then stored in a temporary tank. The mass ratio of mixture to sulfur is (0.1-0.3):(90-100).

[0007] Furthermore, the coarse aggregate is one or a combination of crushed rock, crushed gravel, and slag, and the particle size of the coarse aggregate is 9.5-13.5 mm.

[0008] The fine aggregate is one or a combination of natural sand, machine-made sand, and stone chips, and the particle size of the fine aggregate is 1.2-2.4 mm.

[0009] Furthermore, the filler is one or a combination of mineral powder, limestone powder, diatom powder, fly ash, dolomite powder, marble powder, silica fume, and rubber powder, and the filler particle size is 50-100um.

[0010] Further reinforcing fibers are one or a combination of lignin fibers, basalt fibers, polyester fibers, nylon fibers, glass fibers, and steel fibers.

[0011] Furthermore, the modified self-healing bio-based asphalt is prepared by the following method: a castor oil derivative and 1,5-pentane diisocyanate are mixed in a mass ratio of (0.8-1.2): (1.0-1.5) to obtain a mixture II, which is then heated to 60-70°C under a nitrogen atmosphere, and 0.1-0.3% of the mass of the mixture II is added as a catalyst. The mixture is stirred at 300-600 rpm for 1.5-2.5 hours to obtain a bio-based polyurethane prepolymer containing an nn stacking structure, which is set aside. Pyridine and a vanillin derivative are mixed in a molar ratio of (1.0-1.2): (1.0-1.5), and the mixture is stirred at 400-800 rpm for 1.0-1.5 hours at 55-65°C to obtain a dynamic crosslinker containing an nn stacking structure, which is set aside. Heat 70# or 90# base asphalt to 160-180°C to melt it, then add 1.5-2.5% nanosilica by weight of the base asphalt. Place the mixture in a high-speed shear and shear at 4000-6000 rpm for 25-35 minutes to obtain Mixture III. Slowly add the prepared bio-based polyurethane prepolymer and dynamic crosslinker to Mixture III, with the bio-based polyurethane prepolymer added in an amount of 5-10% by weight of Mixture III and the dynamic crosslinker added in an amount of 1-2% by weight of Mixture III. Shear at 3000-5000 rpm for 30-60 minutes to obtain Mixture IV. Heat Mixture IV to 120-140°C, add 0.1-0.3% dibutyltin dilaurate by weight of Mixture IV as a catalyst, and stir the mixture at 300-600 rpm for 25-35 minutes. Then cool to room temperature to obtain the modified self-healing bio-based asphalt, which is then stored in a temporary tank.

[0012] Furthermore, the castor oil derivative is one of hydrogenated castor oil, epoxidized castor oil, and sulfonated castor oil, and the vanillin derivative is one of vanillin thioether, methoxyacrylate vanillin, quinazolinone vanillin, glucoside vanillin, and mesoionic vanillin.

[0013] Furthermore, the above-mentioned high-viscosity asphalt concrete material is prepared by the following method, comprising the following steps:

[0014] S1. Wash away dust and impurities on the surface of the coarse aggregate and fine aggregate, then place them in a drying barrel and dry them at 80-100°C for 10-20 minutes; spray acrylic resin on the dried coarse aggregate and fine aggregate, then place them in a dryer and dry them at 60-80°C for 1-2 hours to obtain pretreated coarse aggregate and pretreated fine aggregate for later use.

[0015] S2. Take out the nano-montmorillonite / SBR composite modified asphalt from the temporary storage tank and heat it to 130-140°C.

[0016] S3. Add the pretreated coarse aggregate, pretreated fine aggregate, filler, and reinforcing fiber to the heated nano-montmorillonite / SBR composite modified asphalt, and place the mixture in a mixer for stirring to obtain a mixture V.

[0017] S4. Add the modified self-repairing bio-based asphalt taken out from the temporary storage tank to the mixture V and stir evenly to obtain a high-viscosity asphalt concrete material.

[0018] Furthermore, the stirring speed in S3 is 400-800 rpm and the stirring time is 60-120 s. The stirring speed in S4 is 300-600 rpm and the stirring time is 30-60 s.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The present invention modifies asphalt through a nano-montmorillonite / SBR composite, inserting SBR into the interlayers of the nano-montmorillonite. The layered structure of the nano-montmorillonite provides attachment points for the SBR, forming a stable intercalated composite structure that can effectively disperse and transmit stress. When the asphalt concrete is subjected to a load, the stress can be more evenly distributed throughout the material, thereby reducing the phenomenon of local stress concentration. At the same time, the intercalated composite structure formed by the nano-montmorillonite and SBR also enhances the bonding force between the nano-montmorillonite / SBR composite modified asphalt and the aggregate, allowing the asphalt concrete to better disperse stress when subjected to a load, preventing local damage and making the asphalt concrete more durable.

[0021] 2. The present invention adds modified self-repairing bio-based asphalt, the aromatic ring structures contained in it attract each other and stack together through the NN stacking effect, forming a structure with certain strength and stability. The NN stacking effect is a reversible interaction. When the asphalt concrete material is subjected to external forces such as vehicle gravity and produces microcracks, the stacked aromatic rings will temporarily separate, absorbing energy and dispersing stress. When the external forces such as vehicle gravity are removed, these aromatic rings will stack together again, filling the microcracks, thereby achieving self-repair. This dynamic repair mechanism helps the material maintain stable performance during service and extend its service life. At the same time, the self-repair process not only fills the microcracks, but also enhances the toughness of the asphalt concrete material. This enables the material to better absorb energy and disperse stress when subjected to external forces, thereby reducing the risk of damage and destruction. Therefore, by adding this modified self-repairing bio-based asphalt, dynamic repair of microcracks is achieved, thereby significantly improving the fatigue strength, freeze-thaw splitting strength, and Marshall residual stability of the asphalt concrete material. DETAILED DESCRIPTION

[0022] In order to better understand the technical content of the present invention, specific examples are provided below to further illustrate the present invention.

[0023] Unless otherwise specified, the experimental methods used in the examples of the present invention are all conventional methods.

[0024] Unless otherwise specified, the materials, reagents, etc. used in the examples of the present invention can be obtained from commercial sources.

[0025] Example 1

[0026] A high-viscosity asphalt concrete material comprises the following raw materials, in parts by weight: 6 parts nano-montmorillonite / SBR composite modified asphalt, 50 parts coarse aggregate, 20 parts fine aggregate, 5 parts acrylic resin, 4 parts filler, 1.0 part reinforcing fiber, and 0.5 parts modified self-healing bio-based asphalt. The coarse aggregate is crushed rock with a particle size of 9.5 mm, the fine aggregate is natural sand with a particle size of 1.2 mm, the filler is mineral powder with a particle size of 50 μm, and the reinforcing fiber is lignin fiber.

[0027] The nano-montmorillonite / SBR composite modified asphalt is prepared by the following method: Nano-montmorillonite with a particle size of 100 nm and an interlayer spacing of 1 nm is selected and dispersed in deionized water to prepare a nano-montmorillonite suspension. The nano-montmorillonite to deionized water ratio (g / mL) is 1:2. Hexadecyltrimethylammonium bromide is added to the nano-montmorillonite suspension, with a mass-to-volume ratio (g / mL) of hexadecyltrimethylammonium bromide to the nano-montmorillonite suspension of 1.0:40. The mixture is stirred at 60°C for 4 hours, the solids are filtered, washed twice with deionized water, and then dried at 80°C for 15 hours to obtain activated layered nano-montmorillonite, which is then used for later use. SBR latex is diluted with deionized water to a solids content of 10%, sodium lauryl sulfate is added, and the mixture is stirred until uniform. The mass-to-volume ratio (g / mL) of sodium lauryl sulfate to the diluted SBR latex is 0.4:90, resulting in a pretreated SBR latex, which is then used for later use. Activated layered nano-montmorillonite was dispersed in toluene and ultrasonically treated for 25 minutes to form an activated layered nano-montmorillonite suspension. The activated layered nano-montmorillonite to toluene mass / volume ratio (g / mL) was 1:3. Pretreated SBR latex was then slowly added to the activated layered nano-montmorillonite suspension at a volume ratio of 1.5:0.8. The mixture was stirred at 60°C for 4 hours to obtain a nano-montmorillonite / SBR intercalation composite material, which was then set aside. 70# matrix asphalt was heated to 160°C to melt it. The nano-montmorillonite / SBR intercalation composite material was then slowly added to the molten asphalt and placed in a high-speed shearing machine. The mass ratio of the nano-montmorillonite / SBR intercalation composite material to asphalt was 0.5:8. The mixture was stirred at 3000 rpm for 60 minutes to obtain Mixture I. Sulfur was added to Mixture I, and stirring was continued for 20 minutes. The mixture was cooled to room temperature to obtain nano-montmorillonite / SBR composite modified asphalt, which was then stored in a temporary storage tank. The mass ratio of the mixture to sulfur was 0.1:90.

[0028] The modified self-healing bio-based asphalt was prepared by the following method: a castor oil derivative and 1,5-pentanediisocyanate were mixed in a mass ratio of 0.8:1.0 to obtain Mixture II. Under a nitrogen atmosphere, the mixture was heated to 60°C, and dibutyltin dilaurate (0.1% by mass of Mixture II) was added as a catalyst. The mixture was stirred at 300 rpm for 2.5 hours to obtain a bio-based polyurethane prepolymer containing a nn stacking structure, which was set aside. The castor oil derivative was hydrogenated castor oil. Pyridine and a vanillin derivative were mixed in a molar ratio of 1.0:1.0 and stirred at 55°C and 400 rpm for 1.5 hours to obtain a dynamic crosslinker containing a nn stacking structure, which was set aside. The vanillin derivative was vanillin methoxyacrylate. A 70# base asphalt was heated to 160°C to melt, and nanosilica (1.5% by mass of the base asphalt) was added. The mixture was placed in a high-speed shear and sheared at 4000 rpm for 35 minutes to obtain Mixture III. The prepared bio-based polyurethane prepolymer and dynamic crosslinker were slowly added to Mixture III, with the bio-based polyurethane prepolymer added in an amount of 5% by mass and the dynamic crosslinker added in an amount of 1% by mass of Mixture III. The mixture was sheared at 3000 rpm for 60 minutes in a high-speed shearing machine to obtain Mixture IV. Mixture IV was heated to 120°C, and 0.1% by mass of dibutyltin dilaurate was added as a catalyst. The mixture was stirred at 300 rpm for 35 minutes, and then cooled to room temperature to obtain the modified self-healing bio-based asphalt, which was then stored in a temporary tank.

[0029] Example 2

[0030] A high-viscosity asphalt concrete material comprises the following raw materials, in parts by weight: 10 parts nano-montmorillonite / SBR composite modified asphalt, 60 parts coarse aggregate, 30 parts fine aggregate, 10 parts acrylic resin, 8 parts filler, 1.5 parts reinforcing fiber, and 1.0 part modified self-healing bio-based asphalt. The coarse aggregate is crushed gravel with a particle size of 13.5 mm, the fine aggregate is stone chips with a particle size of 2.4 mm, the filler is a combination of fly ash and marble powder in a 1:1 ratio by mass, with a particle size of 100 μm, and the reinforcing fiber is a combination of basalt fiber and glass fiber in a 1:1 ratio by mass.

[0031] The nano-montmorillonite / SBR composite modified asphalt is prepared by the following method: Nano-montmorillonite with a particle size of 300 nm and an interlayer spacing of 3 nm is selected and dispersed in deionized water to prepare a nano-montmorillonite suspension. The nano-montmorillonite to deionized water ratio (g / mL) is 1:4. Hexadecyltrimethylammonium bromide is added to the nano-montmorillonite suspension, with a mass-to-volume ratio (g / mL) of hexadecyltrimethylammonium bromide to the nano-montmorillonite suspension of 1.5:50. The mixture is stirred at 80°C for 2 hours, the solids are filtered, washed three times with deionized water, and then dried at 100°C for 10 hours to obtain activated layered nano-montmorillonite, which is then used for later use. SBR latex is diluted with deionized water to a solids content of 20%, sodium lauryl sulfate is added, and the mixture is stirred evenly. The mass-to-volume ratio (g / mL) of sodium lauryl sulfate to the diluted SBR latex is 0.6:100, resulting in a pretreated SBR latex, which is then used for later use. Activated layered nano-montmorillonite was dispersed in toluene and ultrasonically treated for 25 minutes to form an activated layered nano-montmorillonite suspension. The activated layered nano-montmorillonite to toluene mass / volume ratio (g / mL) was 1:5. Pretreated SBR latex was then slowly added to the activated layered nano-montmorillonite suspension at a volume ratio of 2.5:1.2. The mixture was stirred at 80°C for 2 hours to obtain a nano-montmorillonite / SBR intercalation composite material, which was then used. 90# matrix asphalt was heated to 180°C to melt it. The nano-montmorillonite / SBR intercalation composite material was then slowly added to the molten asphalt and placed in a high-speed shearing machine. The mass ratio of the nano-montmorillonite / SBR intercalation composite material to asphalt was 1.5:12. The mixture was stirred at 5000 rpm for 30 minutes to obtain Mixture I. Sulfur was added to Mixture I, and stirring was continued for 10 minutes. The mixture was cooled to room temperature to obtain nano-montmorillonite / SBR composite modified asphalt, which was then stored in a temporary storage tank. The mass ratio of the mixture to sulfur was 0.3:100.

[0032] The modified self-healing bio-based asphalt was prepared by the following method: a castor oil derivative and 1,5-pentanediisocyanate were mixed in a mass ratio of 1.2:1.5 to obtain Mixture II. Under a nitrogen atmosphere, the mixture was heated to 70°C, and dibutyltin dilaurate (0.3% by mass of Mixture II) was added as a catalyst. The mixture was stirred at 600 rpm for 1.5 hours to obtain a bio-based polyurethane prepolymer containing a nn stacking structure, which was set aside. The castor oil derivative was epoxidized castor oil. Pyridine and a vanillin derivative were mixed in a molar ratio of 1.2:1.5 and stirred at 65°C at 800 rpm for 1.0 hour to obtain a dynamic crosslinker containing a nn stacking structure, which was set aside. The vanillin derivative was quinazolinone vanillin. A 90# base asphalt was heated to 180°C to melt it, and then nanosilica (2.5% by mass of the base asphalt) was added. The mixture was placed in a high-speed shear and sheared at 6000 rpm for 25 minutes to obtain Mixture III. The prepared bio-based polyurethane prepolymer and dynamic crosslinker were slowly added to Mixture III, with the bio-based polyurethane prepolymer added in an amount of 10% by mass and the dynamic crosslinker added in an amount of 2% by mass of Mixture III. The mixture was sheared at 5000 rpm for 30 minutes in a high-speed shearing machine to obtain Mixture IV. Mixture IV was heated to 140°C, and 0.3% by mass of dibutyltin dilaurate was added as a catalyst. The mixture was stirred at 600 rpm for 25 minutes, and then cooled to room temperature to obtain the modified self-healing bio-based asphalt, which was then stored in a temporary tank.

[0033] Example 3

[0034] A high-viscosity asphalt concrete material comprises the following raw materials, in parts by weight: 8 parts nano-montmorillonite / SBR composite modified asphalt, 55 parts coarse aggregate, 25 parts fine aggregate, 7.5 parts acrylic resin, 6 parts filler, 1.2 parts reinforcing fiber, and 0.8 parts modified self-healing bio-based asphalt. The coarse aggregate is a combination of crushed rock and slag in a 1:1 ratio, with a particle size of 11.5 mm; the fine aggregate is a combination of machine-made sand and stone chips in a 1:1 ratio, with a particle size of 1.8 mm; the filler is a combination of limestone powder, silica fume, and rubber powder in a 1:1:1 ratio, with a particle size of 75 μm; and the reinforcing fiber is a combination of basalt fiber, nylon fiber, and steel fiber in a 1:1:1 ratio.

[0035] The nano-montmorillonite / SBR composite modified asphalt was prepared by the following method: Nano-montmorillonite with a particle size of 200 nm and an interlayer spacing of 2 nm was selected and dispersed in deionized water to prepare a nano-montmorillonite suspension. The nano-montmorillonite to deionized water ratio (g / mL) was 1:3. Hexadecyltrimethylammonium bromide was added to the nano-montmorillonite suspension, with a mass-to-volume ratio (g / mL) of 1.2:45. The mixture was stirred at 70°C for 3 hours, the solids were filtered, washed three times with deionized water, and then dried at 90°C for 12.5 hours to obtain activated layered nano-montmorillonite, which was then set aside. SBR latex was diluted with deionized water to a solids content of 15%, sodium lauryl sulfate was added, and the mixture was stirred evenly. The mass-to-volume ratio (g / mL) of sodium lauryl sulfate to the diluted SBR latex was 0.5:95, resulting in a pretreated SBR latex, which was then set aside. Activated layered nano-montmorillonite was dispersed in toluene and ultrasonically treated for 30 minutes to form an activated layered nano-montmorillonite suspension. The activated layered nano-montmorillonite to toluene mass / volume ratio was 1:4 (g / mL). Pretreated SBR latex was then slowly added to the activated layered nano-montmorillonite suspension at a volume ratio of 2.0:1.0. The mixture was stirred at 70°C for 3 hours to obtain a nano-montmorillonite / SBR intercalation composite material, which was then used. 90# matrix asphalt was heated to 170°C to melt it. The nano-montmorillonite / SBR intercalation composite material was then slowly added to the molten asphalt and placed in a high-speed shearing machine. The mass ratio of the nano-montmorillonite / SBR intercalation composite material to asphalt was 1.0:10. The mixture was stirred at 4000 rpm for 45 minutes to obtain Mixture I. Sulfur was added to Mixture I, and stirring was continued for 15 minutes. The mixture was cooled to room temperature to obtain nano-montmorillonite / SBR composite modified asphalt, which was then stored in a temporary storage tank. The mass ratio of the mixture to sulfur was 0.2:95.

[0036] The modified self-healing bio-based asphalt was prepared by the following method: a castor oil derivative and 1,5-pentanediisocyanate were mixed in a mass ratio of 1.0:1.2 to obtain Mixture II. Under a nitrogen atmosphere, the mixture was heated to 65°C, and dibutyltin dilaurate (0.2% by mass of Mixture II) was added as a catalyst. The mixture was stirred at 450 rpm for 2.0 hours to obtain a bio-based polyurethane prepolymer containing a nn stacking structure, which was set aside. The castor oil derivative was sulfonated castor oil. Pyridine and a vanillin derivative were mixed in a molar ratio of 1.1:1.2 and stirred at 60°C and 600 rpm for 1.2 hours to obtain a dynamic crosslinker containing a nn stacking structure, which was set aside. The vanillin derivative was vanillin glucoside. A 90# base asphalt was heated to 170°C to melt, and then nanosilica (2.0% by mass of the base asphalt) was added. The mixture was placed in a high-speed shear and sheared at 5000 rpm for 30 minutes to obtain Mixture III. The prepared bio-based polyurethane prepolymer and dynamic crosslinker were slowly added to Mixture III at a rate of 7.5% by mass of Mixture III and 1.5% by mass of the dynamic crosslinker. The mixture was sheared at 4000 rpm for 45 minutes in a high-speed shearing machine to obtain Mixture IV. Mixture IV was heated to 130°C, and 0.2% by mass of dibutyltin dilaurate was added as a catalyst. The mixture was stirred at 450 rpm for 30 minutes, and then cooled to room temperature to obtain the modified self-healing bio-based asphalt, which was then stored in a temporary tank.

[0037] The high-viscosity asphalt concrete material described in Examples 1-3 above is prepared by the following method, comprising the following steps:

[0038] S1. Wash away dust and impurities on the surface of the coarse aggregate and fine aggregate, then place them in a drying barrel and dry them at 90°C for 15 minutes; spray acrylic resin on the dried coarse aggregate and fine aggregate, then place them in a dryer and dry them at 70°C for 1.5 hours to obtain pretreated coarse aggregate and pretreated fine aggregate for later use.

[0039] S2. Take out the nano-montmorillonite / SBR composite modified asphalt from the temporary storage tank and heat it to 135°C.

[0040] S3. Add the pretreated coarse aggregate, pretreated fine aggregate, filler, and reinforcing fiber to the heated nano-montmorillonite / SBR composite modified asphalt, place the mixture in a mixer and stir at 600 rpm for 90 seconds to obtain a mixture V.

[0041] S4. Add the modified self-repairing bio-based asphalt taken out from the temporary storage tank to the mixture V, and stir at 450 rpm for 45 seconds to obtain a high-viscosity asphalt concrete material.

[0042] Example 4

[0043] Compared with Example 3, this embodiment differs in that the high-viscosity asphalt concrete material is prepared by the following method, comprising the following steps:

[0044] S1. Wash away dust and impurities on the surface of the coarse aggregate and fine aggregate, then place them in a drying barrel and dry them at 80°C for 20 minutes; spray acrylic resin on the dried coarse aggregate and fine aggregate, then place them in a dryer and dry them at 60°C for 1 hour to obtain pretreated coarse aggregate and pretreated fine aggregate for later use.

[0045] S2. Take out the nano-montmorillonite / SBR composite modified asphalt from the temporary storage tank and heat it to 130°C.

[0046] S3. Add the pretreated coarse aggregate, pretreated fine aggregate, filler, and reinforcing fiber to the heated nano-montmorillonite / SBR composite modified asphalt, place the mixture in a mixer and stir at 400 rpm for 120 seconds to obtain mixture V.

[0047] S4. Add the modified self-repairing bio-based asphalt taken out from the temporary storage tank to the mixture V, and stir at 300 rpm for 60 seconds to obtain a high-viscosity asphalt concrete material.

[0048] Example 5

[0049] Compared with Example 3, this embodiment differs in that the high-viscosity asphalt concrete material is prepared by the following method, comprising the following steps:

[0050] S1. Wash away dust and impurities on the surface of the coarse aggregate and fine aggregate, then place them in a drying barrel and dry them at 100°C for 10 minutes; spray acrylic resin on the dried coarse aggregate and fine aggregate, then place them in a dryer and dry them at 80°C for 1 hour to obtain pretreated coarse aggregate and pretreated fine aggregate for later use.

[0051] S2. Take out the nano-montmorillonite / SBR composite modified asphalt from the temporary storage tank and heat it to 140°C.

[0052] S3. Add the pretreated coarse aggregate, pretreated fine aggregate, filler, and reinforcing fiber to the heated nano-montmorillonite / SBR composite modified asphalt, place the mixture in a mixer and stir at 800 rpm for 60 seconds to obtain mixture V.

[0053] S4. Add the modified self-repairing bio-based asphalt taken out from the temporary storage tank to the mixture V, and stir at 600 rpm for 30 seconds to obtain a high-viscosity asphalt concrete material.

[0054] Comparative Example 1

[0055] Compared with Example 3, this comparative example differs in that 90# matrix asphalt is used instead of nano-montmorillonite / SBR composite modified asphalt.

[0056] Comparative Example 2

[0057] This comparative example is compared with Example 3, except that SBR modified asphalt is used instead of nano-montmorillonite / SBR composite modified asphalt. The SBR modified asphalt is prepared by the following method: SBR latex is diluted to a solid content of 15% with deionized water, sodium lauryl sulfate is added, and stirred evenly, wherein the mass volume ratio of sodium lauryl sulfate added to the diluted SBR latex g / mL is 0.5:95, to obtain pre-treated SBR latex. 90# base asphalt is heated to 170°C to melt it, and then the pre-treated SBR latex is slowly added to the molten asphalt and placed in a high-speed shearing machine, wherein the pre-treated SBR latex and asphalt mass ratio is 1.0:10, and stirred for 45 minutes at a speed of 4000 rpm to obtain mixture I. Sulfur is added to mixture I, and stirring is continued for 15 minutes. Cool to room temperature to obtain SBR modified asphalt, which is temporarily stored in a temporary tank. Wherein, the mixture and sulfur mass ratio is 0.2:95.

[0058] Comparative Example 3

[0059] Compared with Example 3, this comparative example differs in that the raw materials do not contain modified self-repairing bio-based asphalt.

[0060] Comparative Example 4

[0061] Compared with Example 3, this comparative example differs in that the high-viscosity asphalt concrete material is prepared by the following method, comprising the following steps:

[0062] S1. Wash away the dust and impurities on the surface of coarse aggregate and fine aggregate, then place them in a drying barrel and dry them at 90℃ for 15 minutes for later use.

[0063] S2. Take out the nano-montmorillonite / SBR composite modified asphalt from the temporary storage tank and heat it to 135°C.

[0064] S3. Add the pretreated coarse aggregate, pretreated fine aggregate, filler, reinforcing fiber, and acrylic resin to the heated nano-montmorillonite / SBR composite modified asphalt, place the mixture in a mixer and stir at 600 rpm for 90 seconds to obtain mixture V.

[0065] S4. Add the modified self-repairing bio-based asphalt taken out from the temporary storage tank to the mixture V, and stir at 450 rpm for 45 seconds to obtain a high-viscosity asphalt concrete material.

[0066] Performance Testing

[0067] 1. Fatigue strength

[0068] The asphalt concrete materials of Examples 1-5 and Comparative Examples 1-4 were fabricated into test pieces with a length of 380 mm, a thickness of 50 mm, and a width of 63.5 mm. The test pieces were then cured. Five test pieces were prepared for each set of Examples and Comparative Examples. The tests were conducted using a universal testing machine under the following conditions: a test temperature of 15°C, a loading frequency of 10 Hz, a sinusoidal loading waveform, and a rest period of 48 hours. The number of intermittent fatigue life tests was used as the fatigue life evaluation indicator. The tests were conducted in accordance with JTGE10-2011, "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering," and T0739-2011, "Four-Point Bending Fatigue Life Test for Asphalt Mixtures." The fatigue strength was calculated as the average value of the five test pieces. The specific results are shown in Table 1.

[0069] 2. Freeze-thaw splitting strength

[0070] In accordance with JTGE10-2011, "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering," the asphalt concrete materials of Examples 1-5 and Comparative Examples 1-4 were prepared using the Marshall compaction method, compacting 50 times on both sides. Five test pieces were prepared for each test. Each test piece was placed at 25°C for 24 hours, then immersed in 25°C water for 2 hours, vacuumed for 15 minutes, and then frozen in a refrigerator at -18°C for 16 hours. Immediately after removal, the test pieces were immersed in 60°C water for 24 hours, followed by another 25°C water immersion for 2 hours. The splitting strength of the test pieces was then measured. The average value of the five test pieces was used as the splitting strength. The specific results are shown in Table 1.

[0071] 3. Marshall residual stability

[0072] With reference to JTGE10-2011, "Testing Procedures for Asphalt and Asphalt Mixtures in Highway Engineering," the asphalt concrete materials of Examples 1-5 and Comparative Examples 1-4 were each made into test pieces using the Marshall compaction method. The asphalt concrete materials were compacted 50 times on each side, resulting in five test pieces. The pieces were then immersed in 60°C water for 60 minutes and 48 hours, respectively. The Marshall stability of each group of test pieces was then tested using a Marshall tester. The Marshall stability of each group was calculated using the following formula to determine the ratio. This ratio is the Marshall residual stability. The larger the ratio, the better the water resistance. The average value of the five test pieces was taken as the Marshall residual stability. The specific results are shown in Table 1. The specific formula is as follows:

[0073] MS=MS1 / MS2×100%

[0074] Among them, MS is the Marshall residual stability (%), MS1 is the stability after immersion in water for 48 hours (kN), and MS2 is the stability after immersion in water for 60 minutes (kN).

[0075] Table 1

[0076]

[0077]

[0078] As can be seen from Table 1, the asphalt concrete material prepared in the present invention has excellent performance in fatigue strength, freeze-thaw splitting strength and Marshall residual stability.

[0079] Comparing Example 3 with Comparative Example 1, Example 3 shows that by inserting SBR into the interlayers of nano-montmorillonite, the layered structure of the nano-montmorillonite provides attachment points for the SBR, forming a stable intercalated composite structure that effectively disperses and transmits stress. This allows the asphalt concrete to be more evenly distributed throughout the material when subjected to load, thereby reducing local stress concentration. The layered structure of the nano-montmorillonite effectively disperses and transmits stress, thereby hindering crack propagation, while the SBR increases the flexibility and ductility of the asphalt, thereby improving the fatigue resistance of the asphalt concrete. The nano-montmorillonite in the intercalated composite structure can form a dense network structure, effectively preventing water penetration and the formation and expansion of ice crystals, thereby reducing damage to asphalt concrete. The addition of SBR further improves the flexibility and adhesion of asphalt concrete, allowing asphalt concrete to better maintain its structural integrity during freeze-thaw cycles. Therefore, the intercalated composite structure enables asphalt concrete to better maintain its structural integrity during freeze-thaw cycles, reducing the erosion of water on the material and thus reducing the destructive effects of freeze-thaw cycles on the material, thereby achieving high freeze-thaw splitting strength. The nano-montmorillonite and SBR in the intercalated composite structure interact to form a more stable network structure, enhancing the durability of asphalt concrete and helping to resist water damage and aging, thereby maintaining a high Marshall residual stability. At the same time, the intercalated composite structure formed by the nano-montmorillonite and SBR also enhances the adhesion between the nano-montmorillonite / SBR composite modified asphalt and aggregate, allowing the asphalt concrete to better distribute stress when subjected to load, preventing localized damage and making the asphalt concrete more durable.

[0080] Compared with Comparative Example 2 by Example 3, in Example 3 nano-montmorillonite / SBR composite modified asphalt, the layered structure of nano-montmorillonite and the intercalated composite structure formed with SBR can effectively disperse stress and prevent the initiation and expansion of cracks. However, the single SBR modified asphalt lacks the layered supporting structure of nano-montmorillonite, and its stress dispersion ability is relatively weak, resulting in that under repeated load, cracks are more likely to generate and expand, thereby reducing fatigue strength. And the SBR in the nano-montmorillonite / SBR composite modified asphalt interacts with the nano-montmorillonite to form a more stable network structure, which enhances the flexibility and elastic recovery ability of asphalt. Although the single SBR modified asphalt also has certain flexibility, it lacks the synergistic effect of nano-montmorillonite, and its elastic recovery ability is relatively weak, and it is difficult to quickly recover its original shape after load action, thereby increasing fatigue damage. At the same time, the intercalated composite structure in the nano-montmorillonite / SBR composite modified asphalt helps to form a more compact asphalt concrete structure, and this dense structure helps to resist the stress generated by freeze-thaw cycles. SBR-modified asphalt alone is unlikely to form such a dense structure, potentially containing more pores and defects. These pores and defects can easily become stress concentration points during freeze-thaw cycles, leading to a reduction in splitting strength. Furthermore, the intercalated composite structure in the nano-montmorillonite / SBR composite modified asphalt forms a more stable network structure, which helps resist the effects of water damage and aging on asphalt concrete. Compared to structures formed by SBR-modified asphalt alone, the intercalated composite structure is more resistant to water damage and aging, thereby maintaining a higher Marshall residual stability.

[0081] Comparing Example 3 with Comparative Example 3, Example 3 obtains a bio-based polyurethane prepolymer containing an nn stacking structure by reacting sulfonated castor oil with 1,5-pentane diisocyanate. In this step, the structure formed after the aromatic ring structure in the castor oil derivative reacts with the isocyanate contains an aromatic ring. Pyridine is mixed with glucoside vanillin to obtain a dynamic crosslinker containing an nn stacking structure. This step also introduces molecules containing an aromatic ring structure. Subsequently, the bio-based polyurethane prepolymer and the dynamic crosslinker are slowly added to the mixture and high-speed shear mixing is performed again. In this process, the aromatic ring structures in the bio-based polyurethane prepolymer and the dynamic crosslinker interact with the molecules in the matrix asphalt to form a stable molecular structure. During the heating and stirring reaction, these aromatic ring structures attract each other and stack together through the nn stacking effect, forming a structure with certain strength and stability. The nn stacking effect is a reversible interaction. When the asphalt concrete material is subjected to external forces such as vehicle gravity to produce microcracks, the stacked aromatic rings will temporarily separate, absorb energy and disperse stress. When external forces such as vehicle weight are removed, these aromatic rings recombine to fill the microcracks, achieving self-healing. Self-healing and filling microcracks eliminates stress concentration points, making stress distribution more uniform and reducing the risk of fatigue damage. Filling microcracks also restores the integrity of the asphalt concrete material, enhancing its resistance to external forces. This helps the material maintain stable performance under repeated loads and improves fatigue life. Filling microcracks also contributes to a denser asphalt concrete structure and improves its water resistance. During freeze-thaw cycles, moisture is less likely to penetrate the material, preserving the bond between the asphalt and aggregate and enhancing freeze-thaw splitting strength. During freeze-thaw cycles, asphalt concrete is susceptible to thermal stresses, which can lead to crack propagation. Self-healing and filling microcracks prevents further crack propagation during freeze-thaw cycles, maintaining the overall stability of the material. Filling microcracks helps reduce environmental damage to the asphalt concrete material and enhances its aging resistance. Under long-term water damage and aging, the material maintains stable performance and resists damage, thereby improving its Marshall residual stability. The NN stacking effect in the modified self-healing bio-based asphalt is a reversible interaction that dynamically repairs microcracks in asphalt concrete when subjected to external forces. This dynamic repair mechanism helps the material maintain stable performance during service, extending its service life. The self-healing process not only fills microcracks but also enhances the toughness of the asphalt concrete. This allows the material to better absorb energy and disperse stress when subjected to external forces, thereby reducing the risk of damage and failure.Therefore, by adding this modified self-healing bio-based asphalt, dynamic repair of microcracks can be achieved, thereby greatly improving the fatigue strength, freeze-thaw splitting strength, and Marshall residual stability of the asphalt concrete material.

[0082] By comparing Example 3 with Comparative Example 4, Example 3 pre-treats coarse aggregate and fine aggregate by spraying, which ensures that acrylic resin is more evenly covered on the aggregate surface, forming a dense film, thereby enhancing the interfacial bonding between aggregate and asphalt. At the same time, pre-treating aggregate by spraying ensures that acrylic resin more fully penetrates into the micropores and cracks on the aggregate surface, further improving the toughness of the material, helping to resist fatigue damage caused by external forces such as vehicle loads, and extending the service life of asphalt concrete materials. At the same time, the film formed by acrylic resin on the aggregate surface can act as a waterproof barrier, reducing the penetration and erosion of moisture on asphalt concrete materials. During the freeze-thaw cycle, this waterproof barrier can protect the bonding between asphalt and aggregate from being destroyed by moisture, thereby improving the freeze-thaw splitting strength of the material. Pre-treating aggregate by spraying ensures that acrylic resin is more fully combined with aggregate to form a stable structure. This stable structure helps to resist deformation and damage under high temperature and load, and improves the Marshall residual stability of the material.

[0083] 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 high-viscosity asphalt concrete material, characterized in that: The invention comprises the following raw materials in parts by weight: 6-10 parts of nano-montmorillonite / SBR composite modified asphalt, 50-60 parts of coarse aggregate, 20-30 parts of fine aggregate, 5-10 parts of acrylic resin, 4-8 parts of filler, 1.0-1.5 parts of reinforcing fiber and 0.5-1.0 parts of modified self-repairing bio-based asphalt.

2. A high viscosity asphalt concrete material according to claim 1, characterized in that: The nano-montmorillonite / SBR composite modified asphalt is prepared by the following method: selecting nano-montmorillonite with a particle size of 100-300 nm and an interlayer spacing of 1-3 nm, dispersing it in deionized water to prepare a nano-montmorillonite suspension, wherein the material-liquid ratio of the nano-montmorillonite to the deionized water is 1:(2-4) g / mL; adding hexadecyltrimethylammonium bromide to the nano-montmorillonite suspension, wherein the mass-volume ratio of the hexadecyltrimethylammonium bromide to the nano-montmorillonite suspension is (1.0-1.5):(40-50) g / mL; stirring at 60-80° C. for 2-4 h, and stirring for 5 minutes. The solid was filtered out and washed with deionized water for 2-3 times, and then dried at 80-100 ° C for 10-15 hours to obtain activated layered nano-montmorillonite for standby use; the SBR latex was diluted with deionized water to a solid content of 10-20%, sodium lauryl sulfate was added, and stirred evenly, wherein the mass volume ratio of the sodium lauryl sulfate addition amount to the diluted SBR latex was (04-0.6): (90-100) to obtain pretreated SBR latex for standby use; the activated layered nano-montmorillonite was dispersed in toluene and ultrasonically treated for 25-35 minutes to form an activated The layered nano-montmorillonite suspension is prepared, wherein the mass volume ratio of the activated layered nano-montmorillonite to toluene is 1:(3-5) g / mL, and then the pretreated SBR latex is slowly added to the activated layered nano-montmorillonite suspension, wherein the volume ratio of the pretreated SBR latex to the activated layered nano-montmorillonite suspension is (1.5-2.5):(0.8-1.2), and the mixture is stirred at 60-80°C for 2-4h to obtain a nano-montmorillonite / SBR intercalated composite material for standby use; 70# or 90# matrix asphalt is heated to 160-180°C to melt it, and then the nano-montmorillonite is added. The soil / SBR intercalation composite material is slowly added to molten asphalt and placed in a high-speed shearing machine, wherein the mass ratio of the nano-montmorillonite / SBR intercalation composite material to asphalt is (0.5-1.5):(8-12), and stirred at a speed of 3000-5000 rpm for 30-60 minutes to obtain a mixture I; sulfur is added to the mixture I, and stirring is continued for 10-20 minutes. The mixture is cooled to room temperature to obtain a nano-montmorillonite / SBR composite modified asphalt, which is temporarily stored in a temporary storage tank. The mass ratio of the mixture to sulfur is (0.1-0.3):(90-100).

3. A high viscosity asphalt concrete material according to claim 1, characterized in that: The coarse aggregate is one or a combination of crushed rock, crushed gravel, and slag, and the particle size of the coarse aggregate is 9.5-13.5 mm.

4. A high-viscosity asphalt concrete material according to claim 1, characterized in that: The fine aggregate is one or a combination of natural sand, machine-made sand, and stone chips, and the particle size of the fine aggregate is 1.2-2.4 mm.

5. The high-viscosity asphalt concrete material according to claim 1, characterized in that: The filler is one or a combination of mineral powder, limestone powder, diatom powder, fly ash, dolomite powder, marble powder, silica fume, and rubber powder, and the filler particle size is 50-100 μm.

6. The high-viscosity asphalt concrete material according to claim 1, characterized in that: The reinforcing fiber is one or a combination of lignin fiber, basalt fiber, polyester fiber, nylon fiber, glass fiber, and steel fiber.

7. The high-viscosity asphalt concrete material according to claim 1, characterized in that: The modified self-repairing bio-based asphalt is prepared by the following method: mixing castor oil derivatives and 1,5-pentane diisocyanate in a mass ratio of (0.8-1.2): (1.0-1.5) to obtain a mixture II, heating the mixture to 60-70°C under a nitrogen atmosphere, adding 0.1-0.3% of dibutyltin dilaurate by mass of the mixture II as a catalyst, stirring the mixture at 300-600 rpm for 1.5-2.5 hours to obtain a bio-based polyurethane prepolymer containing a nn stacking structure for later use; mixing pyridine and vanillin derivatives in a molar ratio of (1.0-1.2): (1.0-1.5), stirring the mixture at 400-800 rpm for 1.0-1.5 hours at 55-65°C to obtain a dynamic crosslinking agent containing a nn stacking structure for later use; heating 70# or 90# matrix asphalt to 160-180°C to melt it, and then adding the matrix Nano-silica with a mass fraction of 1.5-2.5% by weight of asphalt is placed in a high-speed shearing machine and sheared at a speed of 4000-6000 rpm for 25-35 minutes to obtain mixture III; the prepared bio-based polyurethane prepolymer and dynamic crosslinking agent are slowly added to mixture III, the amount of the bio-based polyurethane prepolymer added is 5-10% by weight of mixture III, and the amount of the dynamic crosslinking agent added is 1-2% by weight of mixture III, and sheared at a speed of 3000-5000 rpm for 30-60 minutes in a high-speed shearing machine to obtain mixture IV, the mixture IV is heated to 120-140°C, 0.1-0.3% by weight of dibutyltin dilaurate of mixture IV is added as a catalyst, the mixture is stirred and reacted at 300-600 rpm for 25-35 minutes, and then cooled to room temperature to obtain modified self-repairing bio-based asphalt, which is temporarily stored in a temporary storage tank.

8. The method for preparing a high-viscosity asphalt concrete material according to claim 7, wherein: The castor oil derivative is one of hydrogenated castor oil, epoxidized castor oil, and sulfonated castor oil; the vanillin derivative is one of vanillyl thioether, methoxyacrylate vanillin, quinazolinone vanillin, glucoside vanillin, and mesoionic vanillin.

9. The method for preparing a high-viscosity asphalt concrete material according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Wash away dust and impurities on the surface of the coarse aggregate and fine aggregate, then place them in a drying barrel and dry them at 80-100° C. for 10-20 min; spray acrylic resin on the dried coarse aggregate and fine aggregate, then place them in a dryer and dry them at 60-80° C. for 1-2 h to obtain pretreated coarse aggregate and pretreated fine aggregate for later use; S2. Take out the nano-montmorillonite / SBR composite modified asphalt from the temporary storage tank and heat it to 130-140°C; S3, adding the pretreated coarse aggregate, pretreated fine aggregate, filler, and reinforcing fiber to the heated nano-montmorillonite / SBR composite modified asphalt, and placing the mixture in a mixer and stirring to obtain a mixture V; S4. Add the modified self-repairing bio-based asphalt taken out from the temporary storage tank to the mixture V and stir evenly to obtain a high-viscosity asphalt concrete material.

10. The method for preparing a high-viscosity asphalt concrete material according to claim 9, wherein: In the S3, the stirring speed is 400-800 rpm and the stirring time is 60-120 s; in the S4, the stirring speed is 300-600 rpm and the stirring time is 30-60 s.

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