A targeted anti-aging modified asphalt concrete and a preparation method thereof

Abstract

The present application relates to the field of asphalt concrete material, especially a kind of targeted anti-aging modified asphalt concrete and preparation method thereof.A kind of targeted anti-aging modified asphalt concrete is made from the following weight parts of raw materials: 8-12 parts of non-ionic emulsified asphalt, 15-25 parts of sandstone, 45-75 parts of gravel, 3-6 parts of mineral powder, 0.5-1.0 parts of ZnO@PAN fiber filler, 30-50 parts of rubber powder, 0.20-0.5 parts of anti-aging composition.The asphalt concrete prepared by the present application has excellent anti-aging property, impact toughness, permeability resistance and freeze resistance, effectively prolongs the pavement maintenance cycle and reduces the pavement maintenance cost.

Description

Technical Field

[0001] This invention relates to the field of asphalt concrete materials, and in particular to a targeted anti-aging modified asphalt concrete and its preparation method. Background Technology

[0002] Asphalt concrete is a building pavement material mainly composed of asphalt and aggregates. Compared with traditional gravel pavement, asphalt concrete has excellent impermeability, deformation adaptability and erosion resistance. It can not only improve the stability and comfort of vehicle driving, but also extend tire life, reduce fuel consumption and reduce driving costs.

[0003] Currently, asphalt concrete ages due to external factors such as load, temperature, ultraviolet radiation, and moisture, leading to increased brittleness and susceptibility to transverse and longitudinal cracks, thus affecting the pavement's service life. Addressing the aging problem of asphalt concrete primarily relies on pavement maintenance. Existing asphalt concrete requires periodic maintenance, which is costly. There is an urgent need for a targeted anti-aging modified asphalt concrete and its preparation method. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a targeted anti-aging modified asphalt concrete. By using nonionic emulsified asphalt as the matrix, an anti-aging composition and ZnO@PAN fiber filler are uniformly dispersed in the nonionic emulsified asphalt, effectively improving the anti-aging properties, impact toughness, and impermeability of asphalt concrete pavement, effectively extending the pavement maintenance cycle, and reducing pavement maintenance costs.

[0005] The targeted anti-aging modified asphalt concrete provided by this invention is achieved through the following scheme:

[0006] A targeted anti-aging modified asphalt concrete is made from the following raw materials in parts by weight: 8-12 parts nonionic emulsified asphalt, 15-25 parts sand and gravel, 45-75 parts crushed stone, 3-6 parts mineral powder, 0.5-1.0 parts ZnO@PAN fiber filler, 30-50 parts adhesive powder, and 0.20-0.5 parts anti-aging composition.

[0007] Preferably, the crushed stone comprises 8-15% crushed stone with a particle size of 2.5-5.0 mm, 20-30% crushed stone with a particle size of 5-10 mm, 35-50% crushed stone with a particle size of 10-19 mm, and 25-35% crushed stone with a particle size of 19-31.5 mm. In this invention, by selecting the gradation of crushed stone and aggregate, the impermeability, impact toughness, and anti-aging properties of the prepared modified asphalt concrete can be optimized, which also has a positive effect on improving its anti-aging performance.

[0008] Preferably, the cumulative residue on a 0.075mm sieve of the sand and gravel is ≥95.0%, and the fineness modulus is ≥2.80.

[0009] In this invention, the content of sand and gravel with a particle size of less than 0.075mm is strictly controlled and limited to ≤2%. This is because an excessively high content of sand and gravel with a particle size of less than 0.075mm will lead to the formation of interconnected voids, which will reduce the water erosion resistance, low-temperature cracking resistance, and skeleton structure strength of asphalt concrete pavement, and easily cause problems such as loosening, peeling, rutting, and cracking.

[0010] Preferably, the particle size of the mineral powder is 50-150 mesh.

[0011] Preferably, the nonionic emulsified asphalt comprises a base asphalt, a nonionic emulsifier, a thickener, and water; the thickener is at least one of an inorganic filler combined with hydroxyethyl cellulose, hydroxypropyl methyl cellulose, and a nonionic polyurethane associative thickener; the inorganic filler is at least one of zeolite powder, montmorillonite, kaolin, talc powder, mica powder, calcium carbonate, titanium dioxide, silica, barium sulfate, calcined shell powder, carbon black, and rubber powder; the nonionic emulsifier is at least one of NP-10, SR-1025, EP-10, and SG-10; and the base asphalt is at least two of 70# asphalt, 90# asphalt, and 110# asphalt.

[0012] In this invention, the base asphalt is composed of at least two of 70#, 90#, and 110# asphalt, which can meet the road surface requirements of different latitude regions. Adding inorganic fillers to nonionic emulsified asphalt not only adjusts the viscosity of the nonionic emulsified asphalt but also improves the aging resistance and impermeability of asphalt concrete.

[0013] Preferably, the nonionic emulsified asphalt is made from the following raw materials in parts by weight: 60-80 parts of 70# asphalt, 20-40 parts of 90# asphalt, 1-2 parts of zeolite powder, 0.5-1.25 parts of titanium dioxide, 0.5-1.25 parts of silica, 0.4-0.8 parts of thickener ATE299, 2-4 parts of nonionic emulsifier SR-1025, and 100-150 parts of water.

[0014] Preferably, the ZnO@PAN fiber filler includes a PAN fiber matrix and ZnO whiskers loaded on the PAN fiber matrix. The PAN fiber matrix is ​​composed of PAN fibers with a length of 3 mm, PAN fibers with a length of 6 mm, PAN fibers with a length of 9 mm, and PAN fibers with a length of 12 mm.

[0015] Preferably, the PAN fiber matrix is ​​composed of 10-20% PAN fibers with a length of 3 mm, 20-30% PAN fibers with a length of 6 mm, 20-30% PAN fibers with a length of 9 mm, and 5-10% PAN fibers with a length of 12 mm.

[0016] The graded PAN fiber matrix formed by PAN fibers of different lengths (3mm / 6mm / 9mm / 12mm) can further improve the aging resistance, impermeability, and impact toughness of asphalt concrete, further extend the road maintenance cycle, and reduce road maintenance costs.

[0017] Preferably, the ZnO@PAN fiber filler is prepared as follows:

[0018] Step 1: The PAN fiber matrix is ​​subjected to alkaline hydrolysis to obtain PAN fibers with active carboxyl groups on the surface;

[0019] Step 2: PAN fibers with active carboxyl groups on the surface are modified by aminosiloxane treatment; at the same time, ZnO whiskers are modified by aminosiloxane treatment.

[0020] Step 3: Disperse 10 parts of modified PAN fiber, 0.25-1.0 parts of modified ZnO whiskers and 80-160 parts of N,N-dimethylformamide evenly by ultrasonication to form a suspension. Heat the suspension to 50-65℃ and slowly add 0.05-0.10 parts of NCO-terminated polyurethane prepolymer. Stir and react for 0.5-1.0 hours.

[0021] Step 4: Adjust the temperature to 75-85℃, slowly add 16-hydroxyhexadecanoic acid, and react until -NCO in the system is 0. Remove N,N-dimethylformamide by vacuum distillation to obtain ZnO@PAN fiber filler.

[0022] In this invention, ZnO whiskers and PAN fibers in the ZnO@PAN fiber filler are linked by a reaction of NCO-terminated polyurethane prepolymer (-NCO and -NH2). The resulting -NH-CO-NH- provides good hydrophilicity, allowing the ZnO@PAN fiber filler to be better dispersed in nonionic emulsified asphalt. This further improves the aging resistance, impermeability, and impact toughness of asphalt concrete, extending the road maintenance cycle and reducing maintenance costs. The polyurethane backbone between the ZnO whiskers and PAN fibers exhibits excellent low-temperature flexibility, which helps improve the water erosion resistance and low-temperature cracking resistance of asphalt concrete pavements. Furthermore, the uniform dispersion of ZnO whiskers in nonionic emulsified asphalt improves the structural strength, impermeability, and low-temperature cracking resistance of asphalt concrete pavements, while also enhancing aging resistance, further extending the road maintenance cycle and reducing maintenance costs.

[0023] Preferably, the anti-aging composition is an anti-aging composition antioxidant 1010 combined with at least one of UV-284 and UV-T.

[0024] The present invention mainly uses water-soluble antioxidants and light stabilizers in the selection of anti-aging compositions, which can make the anti-aging compositions uniformly dispersed in non-ionic emulsified asphalt, giving asphalt concrete pavement better anti-aging properties, further extending the pavement maintenance cycle and reducing pavement maintenance costs.

[0025] The present invention provides a method for preparing targeted anti-aging modified asphalt concrete, which is achieved through the following technical solution:

[0026] A method for preparing targeted anti-aging modified asphalt concrete includes the following steps:

[0027] Step 1: Heat the base asphalt to 125-135℃ to obtain the oil phase. At the same time, add nonionic emulsifier, thickener and water and mix evenly to obtain the water phase. Then add the oil phase to the water phase and emulsify in a colloid mill for 3-5 minutes. Discharge the material at 60±5℃ to obtain nonionic emulsified asphalt.

[0028] Step 2: At 60±5℃, add ZnO@PAN fiber filler and anti-aging composition to nonionic emulsified asphalt and mix evenly to obtain emulsified asphalt matrix;

[0029] Step 3: Add rubber powder, sand, mineral powder and crushed stone to the emulsified asphalt matrix and mix thoroughly to obtain asphalt concrete mixture. The obtained asphalt concrete mixture is then paved, initially compacted, moderately compacted and finally compacted to obtain targeted anti-aging modified asphalt concrete.

[0030] The preparation method of this invention is mature, the ingredients and road construction are simple, and it is easy to promote and apply quickly.

[0031] In summary, the present invention has the following advantages:

[0032] 1. The asphalt concrete prepared by this invention has excellent anti-aging properties, impact toughness, impermeability, and freeze-thaw resistance, effectively extending the road maintenance cycle and reducing road maintenance costs.

[0033] 2. This invention is based on non-ionic emulsified asphalt, which has better construction performance and environmental protection performance, and avoids the problems of complex construction, high energy consumption and environmental pollution that exist in traditional asphalt concrete curing.

[0034] 3. The ZnO@PAN fiber filler synthesized in this invention can be uniformly dispersed in non-ionic emulsified asphalt, which can further improve the structural strength, anti-aging properties, impermeability, and impact toughness of asphalt concrete, further extend the road maintenance cycle, and reduce road maintenance costs.

[0035] 4. The anti-aging composition in this invention can be uniformly dispersed in non-ionic emulsified asphalt, giving asphalt concrete pavement better anti-aging properties, further extending the pavement maintenance cycle and reducing pavement maintenance costs. Detailed Implementation

[0036] To further understand the inventiveness and technical advancements of this invention, the preferred embodiments of this invention will be discussed in detail below with reference to examples and comparative examples.

[0037] Example: A targeted anti-aging modified asphalt concrete is made from the following raw materials in parts by weight: 8-12 parts nonionic emulsified asphalt, 15-25 parts sand and gravel, 45-75 parts crushed stone, 3-6 parts mineral powder, 0.5-1.0 parts ZnO@PAN fiber filler, 30-50 parts adhesive powder, and 0.20-0.5 parts anti-aging composition.

[0038] The anti-aging composition includes antioxidants and UV protectants.

[0039] The antioxidant is antioxidant 1010 combined with at least one of UV-284 and UV-T.

[0040] Nonionic emulsified asphalt is made from base asphalt, nonionic emulsifier, thickener, and water.

[0041] The base asphalt is at least two of the following: 70# asphalt, 90# asphalt, and 110# asphalt.

[0042] The thickener is an inorganic filler combined with at least one of hydroxyethyl cellulose, hydroxypropyl methyl cellulose, or a nonionic polyurethane associative thickener. The inorganic filler is at least one of zeolite powder, montmorillonite, kaolin, talc powder, mica powder, calcium carbonate, titanium dioxide, silica, barium sulfate, calcined shell powder, carbon black, or adhesive powder. The nonionic emulsifier is at least one of NP-10, SR-1025, EP-10, or SG-10.

[0043] Specifically, nonionic emulsified asphalt is made from the following raw materials in parts by weight: 60-80 parts of 70# asphalt, 20-40 parts of 90# asphalt, 1-2 parts of zeolite powder, 0.5-1.25 parts of titanium dioxide, 0.5-1.25 parts of silica, 0.4-0.8 parts of thickener ATE299, 2-4 parts of nonionic emulsifier SR-1025, and 100-150 parts of water.

[0044] The crushed stone consists of 8-15% crushed stone with a particle size of 2.5-5.0 mm, 20-30% crushed stone with a particle size of 5-10 mm, 35-50% crushed stone with a particle size of 10-19 mm, and 25-35% crushed stone with a particle size of 19-31.5 mm.

[0045] The cumulative residue of sand and gravel on a 0.075mm sieve is ≥95.0%, and the fineness modulus is ≥2.80.

[0046] ZnO@PAN fiber filler includes a PAN fiber matrix and ZnO whiskers loaded on the PAN fiber matrix. The PAN fiber matrix is ​​composed of PAN fibers with a length of 3 mm, PAN fibers with a length of 6 mm, PAN fibers with a length of 9 mm, and PAN fibers with a length of 12 mm.

[0047] Preferably, the PAN fiber matrix is ​​composed of 10-20% PAN fibers with a length of 3 mm, 20-30% PAN fibers with a length of 6 mm, 20-30% PAN fibers with a length of 9 mm, and 5-10% PAN fibers with a length of 12 mm.

[0048] The preparation method of ZnO@PAN fiber filler is as follows:

[0049] Step 1: The PAN fiber matrix is ​​subjected to alkaline hydrolysis to obtain PAN fibers with active carboxyl groups on the surface;

[0050] Step 2: PAN fibers with active carboxyl groups on the surface are modified by aminosiloxane treatment; at the same time, ZnO whiskers are modified by aminosiloxane treatment.

[0051] Step 3: Disperse 10 parts of modified PAN fiber, 0.25-1.0 parts of modified ZnO whiskers and 80-160 parts of N,N-dimethylformamide evenly by ultrasonication to form a suspension. Heat the suspension to 50-65℃ and slowly add 0.05-0.10 parts of NCO-terminated polyurethane prepolymer. Stir and react for 0.5-1.0 hours.

[0052] Step 4: Adjust the temperature to 75-85℃, slowly add 16-hydroxyhexadecanoic acid, and react until -NCO in the system is 0. Remove N,N-dimethylformamide by vacuum distillation to obtain ZnO@PAN fiber filler.

[0053] A method for preparing targeted anti-aging modified asphalt concrete includes the following steps:

[0054] Step 1: Heat the base asphalt to 125-135℃ to obtain the oil phase. At the same time, add nonionic emulsifier, thickener and water and mix evenly to obtain the water phase. Then add the oil phase to the water phase and emulsify in a colloid mill for 3-5 minutes. Discharge the material at 60±5℃ to obtain nonionic emulsified asphalt.

[0055] Step 2: At 60±5℃, add ZnO@PAN fiber filler and anti-aging composition to nonionic emulsified asphalt and mix evenly to obtain emulsified asphalt matrix;

[0056] Step 3: Add rubber powder, sand, mineral powder and crushed stone to the emulsified asphalt matrix and mix thoroughly to obtain asphalt concrete mixture. The obtained asphalt concrete mixture is then paved, initially compacted, moderately compacted and finally compacted to obtain targeted anti-aging modified asphalt concrete.

[0057] Preparation Example 1: A method for preparing ZnO@PAN fiber filler, comprising the following steps:

[0058] S1, dissolve 5 mL of diethylenetriamine in 1000 mL of anhydrous ethanol, and ultrasonically disperse at 40 kHz / 600 W for 15 min to obtain an alkali treatment solution. Add 5 g of PAN fiber (6 mm in length, provided by Shandong Tonghui Glass Fiber Co., Ltd., 15 μm in diameter, tensile strength ≥500 MPa, density 1.18-1.20 g / m³) to the above alkali treatment solution, heat to 75℃ in a water bath and react for 15 min, filter under reduced pressure, and rinse three times with clean water during the filtration process. The obtained filter material is then subjected to 80°C. Hydrolyzed PAN fibers were obtained by vacuum drying at ℃ / 100Pa for 4 hours. The obtained hydrolyzed PAN fibers were added to 2.0L of 0.25wt% γ-aminopropyltriethoxysilane aqueous solution, 0.5ml of ethanol was added dropwise, and the pH was adjusted to 4 with acetic acid. The solution was heated to 60℃ in a water bath and ultrasonically dispersed at 40kHz / 600W for 45min. The solution was filtered under reduced pressure and rinsed three times with deionized water during the filtration process. The obtained filter material was vacuum dried at 80℃ / 100Pa for 4 hours to obtain KH540 modified polyacrylonitrile fibers.

[0059] The preparation method of KH540 modified zinc oxide whiskers is as follows: 5g of zinc oxide whiskers (tetranexamic zinc oxide whiskers, diameter 0.5-5μm, length 10-50μm, CAS No.: 1314-13-2, XBY-ZnO) are added to 2.0L of 0.25wt% γ-aminopropyltriethoxysilane (KH540) aqueous solution, 0.5ml of ethanol is added dropwise, and the pH is adjusted to 4 with acetic acid. The water bath temperature is raised to 60℃, and the mixture is ultrasonically dispersed at 40kHz / 600W for 45min. The water is removed by vacuum distillation to obtain KH540 modified zinc oxide whiskers.

[0060] The preparation method of NCO-terminated polyurethane prepolymer is as follows: Under nitrogen protection, 180g of dodecyl alcohol random polyether CPE-1500 (hydroxyl value 75.2mgKOH / g, Taizhou Jiayin Chemical Co., Ltd.) with a molecular weight of 1500 was dissolved in 320g of N,N-dimethylformamide DMF solvent. The temperature was raised to 85℃, and 0.001g of dibutyltin dilaurate and 22.24g of isophorone diisocyanate IPDI were added. The mixture was stirred at 200rpm for 2.0h. Then, the temperature was lowered to 75℃, and 5.02g of MDI-100 was added. The mixture was stirred at 200rpm for 30min. The -NCO content of the material was measured (refer to GB / T12009.4-89 standard, i.e., -NCO reacts with di-n-butylamine to form urea, and the -NCO content is determined by hydrochloric acid solution). (Content measured) The NCO content was determined by the acetone-di-n-butylamine method. The moisture was removed by vacuum distillation, cooled to 35°C, discharged, and vacuum-filled to obtain NCO-terminated polyurethane prepolymer.

[0061] S2: Take 10g of KH540 modified polyacrylonitrile fiber prepared in S1, 0.25g of KH540 modified zinc oxide whiskers prepared in S1, and 40g of N,N-dimethylformamide DMF. Mix them evenly at high speed and then ultrasonically disperse (ultrasonic frequency 40kHz, ultrasonic power 400W) for 15min to obtain a suspension. At the same time, prepare an NCO-terminated polyurethane prepolymer drop solution: Take the NCO-terminated polyurethane prepolymer prepared in S1, add N,N-dimethylformamide DMF to dilute it, and obtain an NCO-terminated polyurethane prepolymer drop solution with a solid content of 10%. Heat the suspension to 50℃ in a water bath. Under stirring at 200rpm, slowly add 1.36g of the NCO-terminated polyurethane prepolymer drop solution with a solid content of 10% to the suspension at a dropping rate of 0.10g / 60s. After the drop is completed, continue the reaction for 15min.

[0062] S3, Preparation of 16-hydroxyhexadecanoic acid drop solution: 16-hydroxyhexadecanoic acid and N,N-dimethylformamide (DMF) were mixed evenly to obtain a 5% 16-hydroxyhexadecanoic acid drop solution; the temperature was adjusted to 75℃ by water bath heating, and 2.08g of 16-hydroxyhexadecanoic acid drop solution was slowly added to the suspension at a dropping rate of 0.10g / 60s under stirring at 200rpm. After the addition was completed, the reaction continued for 45min. The -NCO content of the material was tested and found to be 0. The material was filtered under reduced pressure, and rinsed three times with deionized water during the filtration process. The obtained filter material was placed in a crucible, and the crucible was transferred to a vacuum drying oven and vacuum dried at 105℃ / 100Pa for 6h to obtain ZnO@PAN fiber filler.

[0063] The difference between Preparation Example 2 and Preparation Example 1 is as follows: In S2, 10g of KH540 modified polyacrylonitrile fiber prepared in S1, 0.50g of KH540 modified zinc oxide whiskers prepared in S1, and 40g of N,N-dimethylformamide (DMF) were mixed evenly at high speed and ultrasonically dispersed (ultrasonic frequency 40kHz, ultrasonic power 400W) for 15min to obtain a suspension; at the same time, an NCO-terminated polyurethane prepolymer drop solution was prepared: NCO-terminated polyurethane prepolymer prepared in S1 was added... The O-terminated polyurethane prepolymer was diluted with N,N-dimethylformamide (DMF) to obtain a 10% NCO-terminated polyurethane prepolymer drop solution. The suspension was heated to 50°C in a water bath, and 1.36g of the 10% NCO-terminated polyurethane prepolymer drop solution was slowly added to the suspension at a dropping rate of 0.10g / 60s while stirring at 200rpm. After the addition was completed, the reaction was continued for 15min. The remaining steps were the same.

[0064] The difference between Preparation Example 3 and Preparation Example 1 is as follows: In S2, 10g of KH540 modified polyacrylonitrile fiber prepared in S1, 0.75g of KH540 modified zinc oxide whiskers prepared in S1, and 40g of N,N-dimethylformamide (DMF) were mixed evenly at high speed and ultrasonically dispersed (ultrasonic frequency 40kHz, ultrasonic power 400W) for 15min to obtain a suspension; at the same time, an NCO-terminated polyurethane prepolymer drop solution was prepared: NCO-terminated polyurethane prepolymer prepared in S1 was added... The O-terminated polyurethane prepolymer was diluted with N,N-dimethylformamide (DMF) to obtain a 10% NCO-terminated polyurethane prepolymer drop solution. The suspension was heated to 50°C in a water bath, and 1.36g of the 10% NCO-terminated polyurethane prepolymer drop solution was slowly added to the suspension at a dropping rate of 0.10g / 60s while stirring at 200rpm. After the addition was completed, the reaction was continued for 15min. The remaining steps were the same.

[0065] The difference between Preparation Example 4 and Preparation Example 1 is as follows: In S2, 10g of KH540 modified polyacrylonitrile fiber prepared in S1, 1.0g of KH540 modified zinc oxide whiskers prepared in S1, and 40g of N,N-dimethylformamide (DMF) were mixed evenly at high speed and ultrasonically dispersed (ultrasonic frequency 40kHz, ultrasonic power 400W) for 15min to obtain a suspension; at the same time, an NCO-terminated polyurethane prepolymer drop solution was prepared: NCO... The NCO-terminated polyurethane prepolymer was diluted with N,N-dimethylformamide (DMF) to obtain a 10% NCO-terminated polyurethane prepolymer drop solution. The suspension was heated to 50°C in a water bath. Under stirring at 200 rpm, 1.36 g of the 10% NCO-terminated polyurethane prepolymer drop solution was slowly added to the suspension at a dropping rate of 0.10 g / 60 s. After the addition was completed, the reaction was continued for 15 min. The remaining steps were the same.

[0066] The difference between Preparation Example 5 and Preparation Example 1 is as follows: In S2, 10g of KH540 modified polyacrylonitrile fiber prepared in S1, 0.10g of KH540 modified zinc oxide whiskers prepared in S1, and 40g of N,N-dimethylformamide (DMF) were mixed evenly at high speed and ultrasonically dispersed (ultrasonic frequency 40kHz, ultrasonic power 400W) for 15min to obtain a suspension; at the same time, an NCO-terminated polyurethane prepolymer drop solution was prepared: NCO-terminated polyurethane prepolymer prepared in S1 was added... The O-terminated polyurethane prepolymer was diluted with N,N-dimethylformamide (DMF) to obtain a 10% NCO-terminated polyurethane prepolymer drop solution. The suspension was heated to 50°C in a water bath, and 1.36g of the 10% NCO-terminated polyurethane prepolymer drop solution was slowly added to the suspension at a dropping rate of 0.10g / 60s while stirring at 200rpm. After the addition was completed, the reaction was continued for 15min. The remaining steps were the same.

[0067] Preparation Example 6: A method for preparing ZnO / PAN fiber fillers, comprising the following steps:

[0068] S1, dissolve 5 mL of diethylenetriamine in 1000 mL of anhydrous ethanol, and ultrasonically disperse at 40 kHz / 600 W for 15 min to obtain an alkali treatment solution. Add 5 g of PAN fiber (6 mm in length, provided by Shandong Tonghui Glass Fiber Co., Ltd., 15 μm in diameter, tensile strength ≥500 MPa, density 1.18-1.20 g / m³) to the above alkali treatment solution, heat to 75℃ in a water bath and react for 15 min, filter under reduced pressure, and rinse three times with clean water during the filtration process. The obtained filter material is then subjected to 80°C. Hydrolyzed PAN fibers were obtained by vacuum drying at ℃ / 100Pa for 4 hours. The obtained hydrolyzed PAN fibers were added to 2.0L of 0.25wt% γ-aminopropyltriethoxysilane aqueous solution, 0.5ml of ethanol was added dropwise, and the pH was adjusted to 4 with acetic acid. The solution was heated to 60℃ in a water bath and ultrasonically dispersed at 40kHz / 600W for 45min. The solution was filtered under reduced pressure and rinsed three times with deionized water during the filtration process. The obtained filter material was vacuum dried at 80℃ / 100Pa for 4 hours to obtain KH540 modified polyacrylonitrile fibers.

[0069] The preparation method of KH540 modified zinc oxide whiskers is as follows: 5g of zinc oxide whiskers (tetranexamic zinc oxide whiskers, diameter 0.5-5μm, length 10-50μm, CAS No.: 1314-13-2, XBY-ZnO) are added to 2.0L of 0.25wt% γ-aminopropyltriethoxysilane (KH540) aqueous solution, 0.5ml of ethanol is added dropwise, and the pH is adjusted to 4 with acetic acid. The water bath temperature is raised to 60℃, and the mixture is ultrasonically dispersed at 40kHz / 600W for 45min. The water is removed by vacuum distillation to obtain KH540 modified zinc oxide whiskers.

[0070] S2, take 10g of KH540 modified polyacrylonitrile fiber prepared in S1 and 0.25g of KH540 modified zinc oxide whiskers prepared in S1 and mix them evenly to obtain ZnO / PAN fiber filler.

[0071] Example 1: Targeted anti-aging modified asphalt concrete was made from the following raw materials in parts by weight: 10 parts nonionic emulsified asphalt, 25 parts sand and gravel, 70 parts crushed stone, 5 parts 100-mesh magnetite powder, 0.5 parts ZnO@PAN fiber filler as described in Example 1, 40 parts adhesive powder, 0.2 parts antioxidant 1010, and 0.2 parts ultraviolet absorber UV-T. The sand and gravel were commercially available manufactured sand with a fineness modulus of 2.94 and a crushing value of 27.1%.

[0072] The cumulative sieve residue of manufactured sand is 95.8% for 0.075mm, 88.1% for 0.15mm, 78.5% for 0.3mm, 65.0% for 0.60mm, 57.1% for 1.18mm, 40.2% for 2.36mm, and 10.3% for 4.75mm, with a crushing value of 27.1%.

[0073] The crushed stone consists of 10% crushed stone with a particle size of 2.5-5.0 mm, 25% crushed stone with a particle size of 5-10 mm, 40% crushed stone with a particle size of 10-19 mm, and 25% crushed stone with a particle size of 19-31.5 mm. The crushed stone gradation method is as follows: The limestone blocks are crushed and refined. The resulting limestone crushed stone is screened through a 2.5mm mesh screen to remove particles smaller than 2.5mm. The remaining material is then screened through a 5mm mesh screen, producing limestone crushed stone with a particle size of 2.5-5.0mm. Next, the remaining material is screened through a 10mm mesh screen, producing limestone crushed stone with a particle size of 5-10mm. Finally, the remaining material is screened through a 19mm mesh screen, producing limestone crushed stone with a particle size of 10-19mm. The remaining material is then screened through a 31.5mm mesh screen, producing limestone crushed stone with a particle size of 10-19mm. The remaining material is then recycled and crushed for regeneration.

[0074] The rubber powder is composed of road tire rubber powder gradations provided by Cangzhou Zhankuan Rubber Products Co., Ltd. in 10 mesh / 20 mesh / 30 mesh / 40 mesh / 80 mesh sizes. The rubber powder contains 8% 10 mesh road tire rubber powder, 16% 20 mesh road tire rubber powder, 24% 30 mesh road tire rubber powder, 36% 40 mesh road tire rubber powder, and 16% 80 mesh road tire rubber powder.

[0075] UV-T, 2-Phenylenimazole-5-sulfonic acid, CAS: 27503-81-7. Antioxidant 1010, CAS: 6683-19-8, Pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamic acid) ester.

[0076] A method for preparing targeted anti-aging modified asphalt concrete includes the following steps:

[0077] Step 1: Heat 80 parts of 70# asphalt, 20 parts of 90# asphalt, and 1.0 part of BYK organic bentonite CLAYTONE 40 to 135°C to obtain an oil phase. Simultaneously, add 4.0 parts of nonionic emulsifier SR-1025, 0.5 parts of nonionic polyurethane associative thickener ATE 299, and 120 parts of water and mix them evenly to obtain an aqueous phase. Then, add the above-prepared oil phase to the aqueous phase, emulsify it in a colloid mill for 5 minutes, and discharge it at 60°C to obtain nonionic emulsified asphalt.

[0078] Step 2: Take 10 parts of the nonionic emulsified asphalt prepared in Step 1, maintain the temperature at 60°C by water bath heating, and mix 0.5 parts of the ZnO@PAN fiber filler prepared in Preparation Example 1, 0.2 parts of antioxidant 1010, and 0.2 parts of ultraviolet absorber UV-T into the nonionic emulsified asphalt to obtain an emulsified asphalt matrix.

[0079] Step 3: Add 40 parts of rubber powder, 25 parts of sand and gravel, 70 parts of crushed stone, and 5 parts of 100-mesh magnetite powder to the emulsified asphalt matrix and mix thoroughly to obtain asphalt concrete mixture. The resulting asphalt concrete mixture is then paved, initially compacted, moderately compacted, and finally compacted to produce targeted anti-aging modified asphalt concrete.

[0080] The difference between Example 2 and Example 1 is that the targeted anti-aging modified asphalt concrete is made from the following raw materials in parts by weight: 10 parts nonionic emulsified asphalt, 25 parts sand and gravel, 70 parts crushed stone, 5 parts 100-mesh magnetite powder, 0.75 parts ZnO@PAN fiber filler in Preparation Example 1, 40 parts adhesive powder, 0.2 parts antioxidant 1010, and 0.2 parts ultraviolet absorber UV-T.

[0081] The difference between Example 3 and Example 1 is that: a targeted anti-aging modified asphalt concrete is made from the following raw materials in parts by weight: 10 parts nonionic emulsified asphalt, 25 parts sand and gravel, 70 parts crushed stone, 5 parts 100-mesh magnetite powder, 1.0 part ZnO@PAN fiber filler in Preparation Example 1, 40 parts adhesive powder, 0.2 parts antioxidant 1010, and 0.2 parts ultraviolet absorber UV-T.

[0082] The difference between Example 4 and Example 1 is that the targeted anti-aging modified asphalt concrete is made from the following raw materials in parts by weight: 10 parts nonionic emulsified asphalt, 25 parts sand and gravel, 70 parts crushed stone, 5 parts 100-mesh magnetite powder, 0.75 parts ZnO@PAN fiber filler from Preparation Example 2, 40 parts adhesive powder, 0.2 parts antioxidant 1010, and 0.2 parts ultraviolet absorber UV-T.

[0083] The difference between Example 5 and Example 1 is that the targeted anti-aging modified asphalt concrete is made from the following raw materials in parts by weight: 10 parts nonionic emulsified asphalt, 25 parts sand and gravel, 70 parts crushed stone, 5 parts 100-mesh magnetite powder, 0.75 parts ZnO@PAN fiber filler from Preparation Example 3, 40 parts adhesive powder, 0.2 parts antioxidant 1010, and 0.2 parts ultraviolet absorber UV-T.

[0084] The difference between Example 6 and Example 1 is that the targeted anti-aging modified asphalt concrete is made from the following raw materials in parts by weight: 10 parts nonionic emulsified asphalt, 25 parts sand and gravel, 70 parts crushed stone, 5 parts 100-mesh magnetite powder, 0.75 parts ZnO@PAN fiber filler from Preparation Example 4, 40 parts adhesive powder, 0.2 parts antioxidant 1010, and 0.2 parts ultraviolet absorber UV-T.

[0085] The difference between Comparative Example 1 and Example 1 is that the modified asphalt concrete is made from the following raw materials in parts by weight: 10 parts nonionic emulsified asphalt, 25 parts sand and gravel, 70 parts crushed stone, 5 parts 100-mesh magnetite powder, 40 parts adhesive powder, 0.2 parts antioxidant 1010, and 0.2 parts ultraviolet absorber UV-T.

[0086] The difference between Comparative Example 2 and Example 1 is that the modified asphalt concrete was made from the following raw materials in parts by weight: 10 parts nonionic emulsified asphalt, 25 parts sand and gravel, 70 parts crushed stone, 5 parts 100-mesh magnetite powder, 0.25 parts ZnO@PAN fiber filler from Example 1, 40 parts adhesive powder, 0.2 parts antioxidant 1010, and 0.2 parts ultraviolet absorber UV-T.

[0087] The difference between Comparative Example 3 and Example 1 is that the modified asphalt concrete was made from the following raw materials in parts by weight: 10 parts nonionic emulsified asphalt, 25 parts sand and gravel, 70 parts crushed stone, 5 parts 100-mesh magnetite powder, 0.5 parts ZnO@PAN fiber filler in Preparation Example 5, 40 parts adhesive powder, 0.2 parts antioxidant 1010, and 0.2 parts ultraviolet absorber UV-T.

[0088] The difference between Comparative Example 4 and Example 1 is that the modified asphalt concrete was made from the following raw materials in parts by weight: 10 parts nonionic emulsified asphalt, 25 parts sand and gravel, 70 parts crushed stone, 5 parts 100-mesh magnetite powder, 0.5 parts ZnO / PAN fiber filler as in Preparation Example 6, 40 parts adhesive powder, 0.2 parts antioxidant 1010, and 0.2 parts ultraviolet absorber UV-T.

[0089] The difference between Comparative Example 5 and Example 1 is that the modified asphalt concrete was made from the following raw materials in parts by weight: 10 parts nonionic emulsified asphalt, 25 parts sand and gravel, 70 parts crushed stone, 5 parts 100-mesh magnetite powder, 0.75 parts ZnO@PAN fiber filler from Example 1, 40 parts adhesive powder, 0.18 parts antioxidant 1098, 0.22 parts antioxidant 168, and 0.2 parts ultraviolet absorber UV-326.

[0090] Performance testing: The impact toughness and flexural strain (-10°C) of the asphalt concrete in Examples 1-6 and Comparative Examples 1-5 were tested according to JTG / T 3364-02-2019+JTG-E20-2011. The asphalt concrete in Examples 1-6 and Comparative Examples 1-5 were aged according to the long-term aging method in the accelerated aging method for hot-mix asphalt mixtures in JTG-E20-2011, and the impact toughness and flexural strain (-10°C) after aging were tested.

[0091] Table 1: Test parameters of asphalt concrete in Examples 1-6 and Comparative Examples 1-5

[0092]

[0093]

[0094] As can be seen from Example 1, Comparative Examples 1 and 4, and Table 1, the addition of ZnO@PAN fiber filler can improve the anti-aging properties, impact toughness, and impermeability of asphalt concrete.

[0095] Based on Examples 1-3 and Comparative Example 2, and in conjunction with Table 1, it can be seen that controlling the addition amount of ZnO@PAN fiber filler to 0.5-1.0 parts can ensure that asphalt concrete has excellent anti-aging properties, impact toughness, and impermeability.

[0096] Based on Examples 2, 4-6, and Comparative Example 3, and in conjunction with Table 1, it can be seen that synthesizing ZnO@PAN fiber filler with 10 parts of modified PAN fiber and 0.25-1.0 parts of modified ZnO whiskers can ensure that asphalt concrete has excellent anti-aging properties, impact toughness, and impermeability. If the ZnO whisker loading rate is too low, the improvement on the anti-aging properties, impact toughness, and impermeability of asphalt concrete will not be significant.

[0097] As can be seen from Example 1 and Comparative Example 5, and Table 1, the water-soluble anti-aging composition of the present invention can be uniformly dispersed in nonionic emulsified asphalt, giving asphalt concrete pavement better anti-aging properties (anti-aging retention rate 94-95%), while the asphalt concrete pavement prepared in Comparative Example 5 has relatively poor anti-aging properties (anti-aging retention rate 89-90%). Therefore, based on nonionic emulsifiers, the selection of water-soluble antioxidants and light stabilizers can make the anti-aging composition uniformly dispersed in nonionic emulsified asphalt, giving asphalt concrete pavement better anti-aging properties, further extending the pavement maintenance cycle, and reducing pavement maintenance costs.

[0098] In summary, the asphalt concrete prepared by this invention has excellent anti-aging properties, impact toughness, and impermeability, effectively extending the road maintenance cycle and reducing road maintenance costs.

[0099] It should be noted that this specific embodiment is merely an explanation of the technical solution of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A targeted anti-aging modified asphalt concrete, characterized in that: It is made from the following raw materials in parts by weight: 8-12 parts nonionic emulsified asphalt, 15-25 parts sand and gravel, 45-75 parts crushed stone, 3-6 parts mineral powder, 0.5-1.0 parts ZnO@PAN fiber filler, 30-50 parts rubber powder, and 0.20-0.5 parts anti-aging composition.

2. The targeted anti-aging modified asphalt concrete according to claim 1, characterized in that: The crushed stone is composed of 8-15% crushed stone with a particle size of 2.5-5.0 mm, 20-30% crushed stone with a particle size of 5-10 mm, 35-50% crushed stone with a particle size of 10-19 mm, and 25-35% crushed stone with a particle size of 19-31.5 mm.

3. The targeted anti-aging modified asphalt concrete according to claim 1, characterized in that: The aggregate has a cumulative sieve residue of ≥95.0% on a 0.075mm sieve and a fineness modulus of ≥2.

80.

4. The targeted anti-aging modified asphalt concrete according to claim 1, characterized in that: The nonionic emulsified asphalt comprises base asphalt, a nonionic emulsifier, a thickener, and water; the thickener is at least one of inorganic fillers combined with hydroxyethyl cellulose, hydroxypropyl methyl cellulose, and a nonionic polyurethane associative thickener; the inorganic filler is at least one of zeolite powder, montmorillonite, kaolin, talc powder, mica powder, calcium carbonate, titanium dioxide, silica, barium sulfate, calcined shell powder, carbon black, and rubber powder; the nonionic emulsifier is at least one of NP-10, SR-1025, EP-10, and SG-10; and the base asphalt is at least two of 70# asphalt, 90# asphalt, and 110# asphalt.

5. The targeted anti-aging modified asphalt concrete according to claim 4, characterized in that: The nonionic emulsified asphalt is made from the following raw materials in parts by weight: 60-80 parts of 70# asphalt, 20-40 parts of 90# asphalt, 1-2 parts of zeolite powder, 0.5-1.25 parts of titanium dioxide, 0.5-1.25 parts of silica, 0.4-0.8 parts of thickener ATE299, 2-4 parts of nonionic emulsifier SR-1025, and 100-150 parts of water.

6. The targeted anti-aging modified asphalt concrete according to claim 1, characterized in that: The ZnO@PAN fiber filler includes a PAN fiber matrix and ZnO whiskers loaded on the PAN fiber matrix. The PAN fiber matrix is ​​composed of PAN fibers with a length of 3 mm, PAN fibers with a length of 6 mm, PAN fibers with a length of 9 mm, and PAN fibers with a length of 12 mm.

7. The targeted anti-aging modified asphalt concrete according to claim 6, characterized in that: The PAN fiber matrix is ​​composed of 10-20% PAN fibers with a length of 3mm, 20-30% PAN fibers with a length of 6mm, 20-30% PAN fibers with a length of 9mm, and 5-10% PAN fibers with a length of 12mm.

8. The targeted anti-aging modified asphalt concrete according to claim 6, characterized in that: The ZnO@PAN fiber filler is prepared as follows: Step 1: The PAN fiber matrix is ​​subjected to alkaline hydrolysis to obtain PAN fibers with active carboxyl groups on the surface; Step 2: PAN fibers with active carboxyl groups on the surface are modified PAN fibers by aminosiloxane treatment; at the same time, ZnO whiskers are modified ZnO whiskers by aminosiloxane treatment. Step 3: Disperse 10 parts of modified PAN fiber, 0.25-1.0 parts of modified ZnO whiskers and 80-160 parts of N,N-dimethylformamide evenly by ultrasonication to form a suspension. Heat the suspension to 50-65℃ and slowly add 0.05-0.10 parts of NCO-terminated polyurethane prepolymer. Stir and react for 0.5-1.0 hours. Step 4: Adjust the temperature to 75-85℃, slowly add 16-hydroxyhexadecanoic acid, and react until -NCO in the system is 0. Remove N,N-dimethylformamide by vacuum distillation to obtain ZnO@PAN fiber filler.

9. The targeted anti-aging modified asphalt concrete according to claim 7, characterized in that: The anti-aging composition is an anti-aging composition antioxidant 1010 combined with at least one of UV-284 and UV-T.

10. A method for preparing targeted anti-aging modified asphalt concrete according to any one of claims 1-9, characterized in that: The process includes the following steps: Step 1, heating the base asphalt to 125-135℃ to obtain the oil phase, simultaneously adding a nonionic emulsifier, thickener, and water and mixing them evenly to obtain the aqueous phase, then adding the oil phase to the aqueous phase, emulsifying in a colloid mill for 3-5 minutes, and discharging at 60±5℃ to obtain nonionic emulsified asphalt; Step 2, maintaining at 60±5℃, adding ZnO@PAN fiber filler and an anti-aging composition to the nonionic emulsified asphalt and mixing evenly to obtain the emulsified asphalt matrix; Step 3, adding rubber powder, sand, mineral powder, and crushed stone to the emulsified asphalt matrix and mixing thoroughly to obtain asphalt concrete mixture, and then paving, initial compaction, secondary compaction, and final compaction to obtain targeted anti-aging modified asphalt concrete.

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