High-strength asphalt composite material and preparation method thereof

Abstract

The invention discloses a high-strength asphalt composite material and a preparation method thereof, and relates to the technical field of asphalt materials. The high-strength asphalt composite material comprises the following raw materials in parts by weight: 60-80 parts of matrix asphalt, 5-15 parts of glass fibers, 3-10 parts of a nano inorganic filler, 0.5-3 parts of an anti-stripping agent, 1-5 parts of a plasticizer and 0.5-1 part of a modified antioxidant, the preparation method comprises the following steps: reacting 2-n-propyl-4-methyl-6-carboxyl benzimidazole with thionyl chloride to generate an acyl chloride compound; reacting the acyl chloride compound with bis (4-aminophenoxy) dimethyl silane to generate silane modified benzimidazole; enabling the silane modified benzimidazole to react with 11-bromine-1-undecanol to generate a long-chain compound; and reacting the long-chain compound with ethylenediamine tetraacetic acid dianhydride to generate the anti-stripping agent. The high-strength asphalt composite material prepared by the invention has good anti-stripping strength and oxidation resistance.

Description

Technical Field

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

[0002] As an important engineering material, asphalt composite materials are widely used in road construction, waterproofing materials, airport runways and other fields. With the rapid development of the economy and the increasing traffic volume, the performance requirements for infrastructure such as roads are also constantly increasing. Traditional asphalt materials have gradually exposed some shortcomings in high-temperature stability, deformation resistance, durability and other aspects, and it is difficult to meet the needs of modern engineering. Although asphalt composite materials have made certain progress, there are still some problems that need to be solved. First, insufficient high-temperature stability is a prominent problem. Under high temperature or heavy traffic conditions in summer, asphalt pavement is prone to rutting, congestion and other diseases, which affect the service life of the road and driving safety. Secondly, water stability needs to be improved. Under the action of water, the bonding force between asphalt and aggregate may be weakened, resulting in damage such as peeling and potholes on the road surface.

[0003] Furthermore, the durability of asphalt composites needs to be further improved. Long-term exposure to the elements can cause asphalt materials to age due to factors such as ultraviolet light, oxygen, and temperature fluctuations, leading to performance degradation. Furthermore, the complex and costly preparation of some modified asphalt composites limits their widespread application.

[0004] Chinese invention patent publication number CN117363044A discloses a method for preparing an improved high-stability asphalt composite material. The invention improves traditional asphalt to obtain an asphalt composite material with high stability and excellent thermal conductivity, but its anti-stripping performance is poor.

[0005] In summary, it is of great significance to develop a high-strength, aging-resistant and peeling-resistant asphalt composite material. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a high-strength asphalt composite material and a preparation method thereof.

[0007] To achieve the above object, the present invention is implemented through the following technical solutions: A high-strength asphalt composite material, comprising the following raw materials in parts by weight: 60-80 parts of matrix asphalt, 5-15 parts of glass fiber, 3-10 parts of nano inorganic filler, 0.5-3 parts of anti-stripping agent, 1-5 parts of plasticizer, 0.5-1 part of modified antioxidant; The anti-stripping agent is prepared by the following method: S1: 2-n-propyl-4-methyl-6-carboxybenzimidazole reacts with thionyl chloride to form an acyl chloride compound; S2: The acyl chloride compound reacts with bis(4-aminophenoxy)dimethylsilane in the presence of triethylamine to form silane-modified benzimidazole; S3: Under nitrogen protection, silane-modified benzimidazole reacts with 11-bromo-1-undecanol in the presence of sodium hydroxide to form a long-chain compound; S4: The long-chain compound reacts with ethylenediaminetetraacetic acid dianhydride under the catalysis of p-toluenesulfonic acid to generate an anti-stripping agent.

[0008] In step S1, the molar ratio of 2-n-propyl-4-methyl-6-carboxybenzimidazole to thionyl chloride is 1:(2.5-3).

[0009] In step S2, the molar ratio of the acyl chloride compound to bis(4-aminophenoxy)dimethylsilane is (2-2.5):1.

[0010] In step S3, the molar ratio of silane-modified benzimidazole to 11-bromo-1-undecanol is 1:(2-3).

[0011] In step S4, the molar ratio of the long-chain compound to ethylenediaminetetraacetic dianhydride is 1:(1-1.5).

[0012] The modified antioxidant is prepared by the following method: S1: 3,5-di-tert-butyl-4-hydroxybenzyl alcohol reacts with 3-mercaptopropionic acid in the presence of p-toluenesulfonic acid to produce mercapto-modified benzyl alcohol; S2: Mercapto-modified benzyl alcohol reacts with trithiocyanate to generate a modified antioxidant.

[0013] In step S1, the molar ratio of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol to 3-mercaptopropionic acid is 1:1.5.

[0014] In step S2, the molar ratio of the mercapto-modified benzyl alcohol to thiocyanate is 3:1.

[0015] The nano inorganic filler is one of nano silicon dioxide and graphene oxide; the plasticizer is one of dibutyl phthalate, dioctyl phthalate and tricresyl phosphate.

[0016] A method for preparing a high-strength asphalt composite material comprises the following steps: (1) Weigh by weight: 60-80 parts of matrix asphalt, 5-15 parts of glass fiber, 3-10 parts of nano inorganic filler, 0.5-3 parts of anti-stripping agent, 1-5 parts of plasticizer, and 0.5-1 part of modified antioxidant; (2) Heat the matrix asphalt to 160-180°C, perform ultrasonic treatment, add plasticizer and modified antioxidant, and stir for 10-20 minutes; then add anti-stripping agent, glass fiber and nano inorganic filler, stir at high speed for 30-60 minutes, and cool to room temperature to obtain a high-strength asphalt composite material.

[0017] Due to the adoption of the above technical solution, the beneficial effects of the present invention include: (1) The present invention involves the reaction of 2-n-propyl-4-methyl-6-carboxybenzimidazole with thionyl chloride to generate an acyl chloride compound; the acyl chloride compound reacts with bis(4-aminophenoxy)dimethylsilane to generate a silane-modified benzimidazole; the silane-modified benzimidazole reacts with 11-bromo-1-undecanol to generate a long-chain compound; and the hydroxyl group of the long-chain compound reacts with the anhydride of ethylenediaminetetraacetic dianhydride to generate a cross-linked anti-stripping agent through an esterification reaction.

[0018] (2) The present invention generates mercapto-modified benzyl alcohol by reacting 3,5-di-tert-butyl-4-hydroxybenzyl alcohol with 3-mercaptopropionic acid; and generates a modified antioxidant by reacting the mercapto-modified benzyl alcohol with thiocyanic acid.

[0019] (3) The phenolic hydroxyl group in the modified antioxidant prepared by the present invention is surrounded by two larger tert-butyl groups, forming a steric hindrance effect, which significantly improves the stability of the phenolic hydroxyl group. This structure can effectively capture free radicals generated during the asphalt oxidation process by providing hydrogen atoms, blocking the free radical chain reaction and delaying the thermal oxidative aging of the asphalt. At the same time, the rigid ring structure and cross-linked network introduced by trithiocyanate make the antioxidant less likely to decompose at high temperatures in the asphalt, maintaining its activity. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the embodiments, but the present invention is not limited to these embodiments.

[0021] Example 1 Preparation of anti-stripping agent: S1: Add 200 ml of chloroform, 0.1 mol of 2-n-propyl-4-methyl-6-carboxybenzimidazole and 0.25 mol of thionyl chloride to a reactor, stir and mix, heat to reflux for 4 hours, cool to room temperature, and distill under reduced pressure at 50°C for 3 hours to obtain an acyl chloride compound; the reaction equation is as follows:

[0022] S2: Under ice bath, add 400 ml of dichloromethane and 0.1 mol of bis(4-aminophenoxy)dimethylsilane to the reactor, stir and mix, then add 0.2 mol of acyl chloride compound in batches (0.05 mol each time, with a batch interval of 5 minutes), then slowly add 0.25 mol of triethylamine dropwise for 10 minutes, warm to room temperature and react for 2 hours, filter, wash three times with saturated NaHCO3 solution (200 ml each time), and dry in vacuo at 60°C for 3 hours to obtain silane-modified benzimidazole; the reaction equation is as follows:

[0023] S3: Under nitrogen protection, 600 ml of dimethyl sulfoxide, 0.1 mol of silane-modified benzimidazole and 0.25 mol of sodium hydroxide were added to the reactor, stirred and mixed, and the temperature was raised to 40°C. Then, 0.2 mol of 11-bromo-1-undecanol was slowly added dropwise for 20 minutes. After the addition was completed and the reaction was allowed to proceed for 5 hours, 200 ml of deionized water was added, and then the mixture was extracted three times with 400 ml of dichloromethane and distilled under reduced pressure at 60°C for 4 hours to obtain a long-chain compound. The reaction equation is shown below:

[0024] Its H-NMR spectrum data are as follows: 1 H NMR (500 MHz, Chloroform-d) δ 9.71 (s, 2H), 7.97 – 7.93 (m, 2H), 7.89 (d, J = 2.2 Hz, 2H), 7.57 – 7.51 (m, 4H), 6.94 – 6.88 (m, 4H), 4.11 (t,J = 6.8 Hz, 4H), 3.54 (q, J = 5.8 Hz, 4H), 2.80 (t, J = 5.9 Hz, 2H), 2.67 –2.61 (m, 10H), 1.84 – 1.66 (m, 8H), 1.62 – 1.53 (m, 4H), 1.41 – 1.31 (m, 8H),1.34 – 1.26 (m, 6H), 1.30 – 1.23 (m, 6H), 1.27 (s, 8H), 1.04 (t, J = 7.5 Hz, 6H), 0.33 (s, 6H).

[0025] S4: Add 500 ml of DMSO, 0.1 mol of the long-chain compound, 0.1 mol of ethylenediaminetetraacetic dianhydride and 0.1 mol of p-toluenesulfonic acid into the reactor, stir and mix, react at room temperature for 4 h, add saturated NaHCO3 solution to adjust the pH value to neutral, distill under reduced pressure at 65°C for 3 h, and vacuum dry at 70°C for 5 h to obtain an anti-stripping agent.

[0026] Example 2 Preparation of anti-stripping agent: S1: Add 200 ml of chloroform, 0.1 mol of 2-n-propyl-4-methyl-6-carboxybenzimidazole and 0.28 mol of thionyl chloride to a reactor, stir and mix, heat to reflux and react for 5 h, cool to room temperature, and distill under reduced pressure at 50°C for 3 h to obtain an acyl chloride compound; S2: Under ice bath, add 400 ml of dichloromethane and 0.1 mol of bis(4-aminophenoxy)dimethylsilane to the reactor and stir to mix. Then, add 0.22 mol of acyl chloride compound in batches (0.055 mol each time, with a batch interval of 5 min). Then, slowly add 0.25 mol of triethylamine dropwise for 10 min. Warm up to room temperature and react for 2.5 h. Filter, wash three times with saturated NaHCO3 solution (200 ml each time), and dry in vacuo at 60°C for 3 h to obtain silane-modified benzimidazole. S3: Under nitrogen protection, 600 ml of dimethyl sulfoxide, 0.1 mol of silane-modified benzimidazole and 0.25 mol of sodium hydroxide were added to the reactor, stirred and mixed, and the temperature was raised to 50°C. Then, 0.25 mol of 11-bromo-1-undecanol was slowly added dropwise for 20 minutes. After the addition was completed and the reaction was allowed to proceed for 4 hours, 200 ml of deionized water was added, and then the mixture was extracted three times with 400 ml of dichloromethane. The mixture was distilled under reduced pressure at 60°C for 4 hours to obtain a long-chain compound; S4: Add 500 ml of DMSO, 0.1 mol of the long-chain compound, 0.12 mol of ethylenediaminetetraacetic dianhydride and 0.1 mol of p-toluenesulfonic acid into the reactor, stir and mix, react at room temperature for 3 h, add saturated NaHCO3 solution to adjust the pH value to neutral, distill under reduced pressure at 65°C for 3 h, and vacuum dry at 70°C for 5 h to obtain an anti-stripping agent.

[0027] Example 3 Preparation of anti-stripping agent: S1: Add 200 ml of chloroform, 0.1 mol of 2-n-propyl-4-methyl-6-carboxybenzimidazole and 0.3 mol of thionyl chloride to a reactor, stir and mix, heat to reflux and react for 6 hours, cool to room temperature, and distill under reduced pressure at 50°C for 3 hours to obtain an acyl chloride compound; S2: Under ice bath, add 400 ml of dichloromethane and 0.1 mol of bis(4-aminophenoxy)dimethylsilane to the reactor and stir to mix. Then, add 0.25 mol of acyl chloride compound in batches (0.05 mol each time, with a batch interval of 5 min). Then, slowly add 0.25 mol of triethylamine dropwise for 10 min. Warm up to room temperature and react for 3 h. Filter, wash three times with saturated NaHCO3 solution (200 ml each time), and dry in vacuo at 60°C for 3 h to obtain silane-modified benzimidazole. S3: Under nitrogen protection, 600 ml of dimethyl sulfoxide, 0.1 mol of silane-modified benzimidazole and 0.25 mol of sodium hydroxide were added to the reactor, stirred and mixed, and the temperature was raised to 60°C. Then, 0.3 mol of 11-bromo-1-undecanol was slowly added dropwise for 20 minutes. After the addition was completed and the reaction was allowed to proceed for 3 hours, 200 ml of deionized water was added, and then the mixture was extracted three times with 400 ml of dichloromethane. The mixture was distilled under reduced pressure at 60°C for 4 hours to obtain a long-chain compound; S4: Add 500 ml of DMSO, 0.1 mol of the long-chain compound, 0.15 mol of ethylenediaminetetraacetic dianhydride and 0.1 mol of p-toluenesulfonic acid into the reactor, stir and mix, react at room temperature for 2 h, add saturated NaHCO3 solution to adjust the pH value to neutral, distill under reduced pressure at 65°C for 3 h, and vacuum dry at 70°C for 5 h to obtain an anti-stripping agent.

[0028] Example 4 Preparation of modified antioxidant: S1: Under nitrogen protection, 300 ml of DMSO, 0.1 mol of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol, and 0.15 mol of 3-mercaptopropionic acid (CAS No. 107-96-0) were added to a reactor. The temperature was raised to 80°C, and then 20 g of p-toluenesulfonic acid was added. The reaction was carried out for 6 h (a water separator was used to remove the generated water during the reaction). The temperature was then cooled to room temperature, and a saturated sodium bicarbonate solution was slowly added to adjust the pH to neutral. The mixture was stirred thoroughly for 30 min, and the mixture was allowed to stand for stratification. The organic phase was transferred to a rotary evaporator and distilled under reduced pressure at 50°C for 4 h. The mixture was then dried under vacuum at 70°C for 2 h to obtain mercapto-modified benzyl alcohol. The reaction equation is shown below:

[0029] S2: Under nitrogen protection, 500 ml of DMSO, 0.3 mol of mercapto-modified benzyl alcohol, and 0.1 mol of trithiocyanate were added to the reactor, stirred and mixed, and the temperature was raised to 80°C. Then, 6 g of initiator AIBN was added. After reacting for 10 hours, the mixture was distilled under reduced pressure at 60°C for 3 hours and dried under vacuum at 70°C for 3 hours to obtain a modified antioxidant. The reaction equation is shown below:

[0030] Its H-NMR spectrum data are as follows: 1 H NMR (500 MHz, Chloroform-d) δ 7.19 (d, J = 0.8 Hz, 6H), 5.18 (t, J= 0.8 Hz, 6H), 4.79 (s, 3H), 3.16 (t, J = 6.0 Hz, 6H), 2.70 (t, J = 6.0 Hz, 6H), 1.41 (s, 54H).

[0031] Example 5 Preparation of high-strength asphalt composite material: (1) Weigh: 600 g of matrix asphalt, 50 g of glass fiber, 30 g of nano-inorganic filler (nano-silica), 5 g of anti-stripping agent (prepared in Example 1), 10 g of plasticizer (dibutyl phthalate), and 5 g of modified antioxidant (prepared in Example 4); (2) Heat the base asphalt to 160°C and use ultrasonic technology to treat the base asphalt at a power of 300W for 20 minutes. Then add plasticizer and modified antioxidant and stir for 20 minutes. Add anti-stripping agent, glass fiber and nano inorganic filler and stir at 1000 rpm for 60 minutes. Cool to room temperature to obtain a high-strength asphalt composite material.

[0032] Example 6 Preparation of high-strength asphalt composite material: (1) Weigh: 700 g of matrix asphalt, 100 g of glass fiber, 60 g of nano-inorganic filler (graphene oxide), 15 g of anti-stripping agent (prepared in Example 2), 30 g of plasticizer (dioctyl phthalate), and 8 g of modified antioxidant (prepared in Example 4); (2) Heat the base asphalt to 170°C and use ultrasonic technology to treat the base asphalt at a power of 300W for 20 minutes. Then add plasticizer and modified antioxidant and stir for 15 minutes. Add anti-stripping agent, glass fiber and nano inorganic filler and stir at 1500 rpm for 45 minutes. Cool to room temperature to obtain a high-strength asphalt composite material.

[0033] Example 7 Preparation of high-strength asphalt composite material: (1) Weigh: 800 g of matrix asphalt, 150 g of glass fiber, 100 g of nano-inorganic filler (nano-silica), 30 g of anti-stripping agent (prepared in Example 3), 50 g of plasticizer (tricresyl phosphate), and 10 g of modified antioxidant (prepared in Example 4); (2) Heat the base asphalt to 180°C and use ultrasonic technology to treat the base asphalt at a power of 300W for 20 minutes. Then add plasticizer and modified antioxidant and stir for 10 minutes. Add anti-stripping agent, glass fiber and nano inorganic filler and stir at 2000rpm for 30 minutes. Cool to room temperature to obtain a high-strength asphalt composite material.

[0034] Comparative Example 1 The raw material composition and process of the high-strength asphalt composite material are basically the same as those in Example 6, except that the anti-stripping agent is replaced by an anti-stripping agent prepared by the following method of equal weight: The preparation method of the anti-stripping agent is basically the same as that of Example 2, except that the 2-n-propyl-4-methyl-6-carboxybenzimidazole in step S1 is replaced by an equal weight of urocanic acid.

[0035] Comparative Example 2 The raw material composition and process of the high-strength asphalt composite material are basically the same as those in Example 6, except that the anti-stripping agent is replaced by an anti-stripping agent prepared by the following method of equal weight: The preparation method of the anti-stripping agent is basically the same as that of Example 2, except that the bis(4-aminophenoxy)dimethylsilane in step S2 is replaced by an equal weight of γ-aminopropyltriethoxysilane.

[0036] Comparative Example 3 The raw material composition and process of the high-strength asphalt composite material are basically the same as those in Example 6, except that the anti-stripping agent is replaced by an anti-stripping agent prepared by the following method of equal weight: The preparation method of the anti-stripping agent is basically the same as that of Example 2, except that the 11-bromo-1-undecanol in step S3 is replaced by an equal weight of 4-bromo-1-butanol.

[0037] Comparative Example 4 The raw material composition and process of the high-strength asphalt composite material are basically the same as those in Example 6, except that the anti-stripping agent is replaced by an anti-stripping agent prepared by the following method of equal weight: The preparation method of the anti-stripping agent is basically the same as that of Example 2, except that the ethylenediaminetetraacetic acid dianhydride in step S4 is replaced by an equal weight of 2,3-pyridinedicarboxylic anhydride.

[0038] Comparative Example 5 The raw material composition and process of the high-strength asphalt composite material are basically the same as those in Example 6, except that the modified antioxidant is replaced by an equal weight of a modified antioxidant prepared by the following method: The preparation method of the modified antioxidant is basically the same as that of Example 4, except that the 3-mercaptopropionic acid in step S1 is replaced by an equal weight of acrylic acid.

[0039] Comparative Example 6 The raw material composition and process of the high-strength asphalt composite material are basically the same as those in Example 6, except that the modified antioxidant is replaced by an equal weight of a modified antioxidant prepared by the following method: The preparation method of the modified antioxidant is basically the same as that of Example 4, except that the thiocyanate in step S2 is replaced by an equal weight of 2,5-dimercaptothiadiazole.

[0040] Comparative Example 7 An improved high-stability asphalt composite material is produced using the raw material composition and process of Example 1 of the Chinese invention patent publication number CN117363044A.

[0041] The matrix asphalt used in the examples and comparative examples of the present application is AH-70 road petroleum asphalt, purchased from Liaohe Petrochemical Branch of China National Petroleum Corporation; the glass fiber is Cem-FIL® alkali-resistant glass fiber, purchased from Taishan Glass Fiber Co., Ltd.; the nano-silica particle size is 15 nm, purchased from Shanghai Guipu Chemical Co., Ltd.; and the graphene oxide is SE3122 graphene oxide dispersion, purchased from Changzhou Sixth Element Materials Technology Co., Ltd.

[0042] Asphalt adhesion tests were conducted according to the water boiling procedure in JTG E20-2011, T0616-1993. Acidic granite aggregate with a particle size of 13.2-19 mm was used. The aggregate was washed and dried. The aggregate was then immersed in asphalt for 45 seconds, removed, cooled at room temperature for 15 minutes, and then immersed in slightly boiling water for 3 minutes. The adhesion of the asphalt film on the aggregate surface was observed, and the degree of flaking was evaluated.

[0043] Asphalt oxidation resistance was tested using the rotating thin film oven test (T 0610-2011) according to JTG E20-2011, with the softening point (T 0606-2011) used as the evaluation index for oxidation resistance. The test results are shown in Table 1.

[0044] The asphalt compressive strength test was conducted in accordance with the method of T 0713-2000 in JTG E20-2011. The asphalt composite material was prepared into a mixture and tested after 10 days of standard curing. The asphalt mixture was prepared by the following method: the asphalt composite material prepared in the embodiment or comparative example was heated to 180°C, 200g of the heated asphalt composite material was mixed with 300g of fine aggregate and 600g of coarse aggregate, and stirred for 30 minutes. The coarse aggregate was basalt crushed stone with a particle size of 5-8mm and an apparent relative density of 2.83, purchased from Jiangsu Yabang Mining Co., Ltd. The fine aggregate was basalt machine-made sand with a particle size of 1-2mm and an apparent relative density of 2.75, purchased from Jiangsu Yabang Mining Co., Ltd. Aging performance test: After the specimens are cured for 10 days, they are placed in a forced ventilation oven, heated to 85°C and exposed to ultraviolet light using a 1000W high-pressure mercury lamp for 5 days of long-term aging. After aging, they are naturally cooled to room temperature and placed for 5 hours before the mechanical properties test.

[0045] Table 1 Performance indicators of asphalt composite materials

[0046] It can be seen from Table 1 that the high-strength asphalt composite materials prepared in Examples 5-7 of the present application have excellent anti-stripping strength and antioxidant properties. This is because the benzimidazole ring introduced into the anti-stripping agent prepared in the present application is a heterocyclic structure containing two nitrogen atoms, which has a strong polarity. In the asphalt composite material system, it can undergo a strong adsorption effect with the polar components in the asphalt through hydrogen bonds, π-π interactions, etc. This adsorption effect enables the anti-stripping agent to be firmly attached to the asphalt surface, thereby enhancing the bonding force between the anti-stripping agent and the asphalt and reducing the peeling of the asphalt from the aggregate surface. At the same time, the introduced silicon-oxygen bond has a higher bond energy and polarity. At the interface between the asphalt and the aggregate, the silane structure can react chemically with the hydroxyl groups on the aggregate surface to form a strong chemical bond, and can also entangle with the asphalt molecules, thereby establishing an effective bridge between the asphalt and the aggregate, greatly enhancing the bonding force between the two. In addition, the long-chain alkyl structure introduced by 11-bromo-1-undecanol has good flexibility. In asphalt composites, the long-chain structure can increase the flexibility and ductility of asphalt. When the asphalt composite is subjected to external force, the long-chain structure can absorb and disperse energy, reduce stress concentration, and prevent the interface between asphalt and aggregate from being damaged due to excessive stress, thereby improving the anti-stripping performance.

[0047] The phenolic hydroxyl group in the 3,5-di-tert-butyl-4-hydroxybenzyl alcohol introduced into the prepared modified antioxidant is surrounded by two larger tert-butyl groups, creating a steric hindrance effect that significantly enhances its stability. This structure effectively captures free radicals generated during asphalt oxidation by providing hydrogen atoms, blocking free radical chain reactions and slowing the asphalt's thermal oxidative aging. The rigid ring structure and cross-linked network introduced by trithiocyanate prevent the antioxidant from decomposing at high temperatures in the asphalt, maintaining its activity. Furthermore, the presence of disulfide bonds enhances the asphalt's self-healing properties.

[0048] The high-strength asphalt composite material prepared in Comparative Example 1 has poor anti-stripping strength. This is because urocanic acid contains imidazole rings, which are less stable than benzimidazole rings. Long-term exposure to high temperature environments may partially degrade, resulting in a decrease in anti-stripping performance.

[0049] The high-strength asphalt composite material prepared in Comparative Example 2 has poorer anti-stripping strength than that prepared in Example 6. This is because there is only one amino group in γ-aminopropyltriethoxysilane, which reduces the benzimidazole ring contained in the prepared anti-stripping agent, thereby reducing the anti-stripping performance.

[0050] The high-strength asphalt composite material prepared in Comparative Example 3 has poorer anti-stripping strength than that prepared in Example 6. 11-bromo-1-undecanol has a longer alkyl chain (11 carbons) and stronger hydrophobicity, which can form stronger physical adsorption with non-polar components in asphalt (such as asphaltenes), while enhancing the anchoring effect with the aggregate surface; the short carbon chain (4 carbons) of 4-bromo-1-butanol is less hydrophobic, has poor compatibility with asphalt, and is difficult to form a stable interface layer. The long-chain structure of 11-bromo-1-undecanol can form a dense monolayer at the interface between asphalt and aggregate, enhancing adhesion through the dual effects of van der Waals forces and chemical bonding, and effectively blocking moisture erosion. However, the short-chain adsorption layer of 4-bromo-1-butanol is thinner and easily destroyed by water molecules.

[0051] The high-strength asphalt composite material prepared in Comparative Example 4 has lower compressive strength than that prepared in Example 6, as 2,3-pyridinedicarboxylic anhydride cannot form a cross-linked structure with long-chain compounds. The anti-stripping agent prepared in this application has a cross-linked structure. The cross-linked structure forms a stable structure through chemical bonds (such as the reaction of hydroxyl groups with Si-OH / Al-OH in the aggregate). It can be anchored to the asphalt and aggregate surfaces simultaneously, improving interfacial bonding strength, helping to improve the stability of the anti-stripping agent in asphalt, and thus improving the anti-stripping performance.

[0052] The high-strength asphalt composite material prepared in Comparative Example 5 has poorer antioxidant properties than that prepared in Example 6. This is because acrylic acid does not contain thiol groups and cannot react with the three SH active sites of trithiocyanate to form disulfide bonds, resulting in poor thermal stability of the modified antioxidant.

[0053] The high-strength asphalt composite material prepared in Comparative Example 6 has poorer antioxidant properties than that prepared in Example 6. This is because 2,5-dimercaptothiadiazole does not contain a triazine ring, the molecular thermal stability is relatively poor, and the antioxidant is easily volatilized or migrated, resulting in poor antioxidant properties.

[0054] Comparative Example 7 is an improved high-stability asphalt composite material made with the raw material composition and process in Example 1 of the Chinese invention patent CN117363044A. As can be seen from Table 1, the anti-stripping performance and anti-oxidation performance are not as good as those of the present application.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. However, any equivalent changes, modifications and evolutions made by ordinary technicians in this field without departing from the scope of the technical solution of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of protection of the technical solution of the present invention.

Claims

1. A high-strength asphalt composite material, characterized in that: The composition comprises the following raw materials in parts by weight: 60-80 parts of matrix asphalt, 5-15 parts of glass fiber, 3-10 parts of nano inorganic filler, 0.5-3 parts of anti-stripping agent, 1-5 parts of plasticizer, 0.5-1 part of modified antioxidant; The anti-stripping agent is prepared by the following method: S1: 2-n-propyl-4-methyl-6-carboxybenzimidazole reacts with thionyl chloride to form an acyl chloride compound; S2: The acyl chloride compound reacts with bis(4-aminophenoxy)dimethylsilane in the presence of triethylamine to form silane-modified benzimidazole; S3: Under nitrogen protection, silane-modified benzimidazole reacts with 11-bromo-1-undecanol in the presence of sodium hydroxide to form a long-chain compound; S4: The long-chain compound reacts with ethylenediaminetetraacetic acid dianhydride under the catalysis of p-toluenesulfonic acid to generate an anti-stripping agent.

2. The high-strength asphalt composite material according to claim 1, characterized in that: In step S1, the molar ratio of 2-n-propyl-4-methyl-6-carboxybenzimidazole to thionyl chloride is 1:(2.5-3).

3. The high-strength asphalt composite material according to claim 1, characterized in that: In step S2, the molar ratio of the acyl chloride compound to bis(4-aminophenoxy)dimethylsilane is (2-2.5):

1.

4. The high-strength asphalt composite material according to claim 1, characterized in that: In step S3, the molar ratio of silane-modified benzimidazole to 11-bromo-1-undecanol is 1:(2-3).

5. The high-strength asphalt composite material according to claim 1, characterized in that: In step S4, the molar ratio of the long-chain compound to ethylenediaminetetraacetic dianhydride is 1:(1-1.5).

6. The high-strength asphalt composite material according to claim 1, characterized in that: The modified antioxidant is prepared by the following method: S1: 3,5-di-tert-butyl-4-hydroxybenzyl alcohol reacts with 3-mercaptopropionic acid in the presence of p-toluenesulfonic acid to produce mercapto-modified benzyl alcohol; S2: Mercapto-modified benzyl alcohol reacts with trithiocyanate to generate a modified antioxidant.

7. The high-strength asphalt composite material according to claim 6, characterized in that: In step S1, the molar ratio of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol to 3-mercaptopropionic acid is 1:1.

5.

8. The high-strength asphalt composite material according to claim 6, characterized in that: In the step S2, the molar ratio of the mercapto-modified benzyl alcohol to thiocyanate is 3:

1.

9. The high-strength asphalt composite material according to claim 1, characterized in that: The nano inorganic filler is one of nano silicon dioxide and graphene oxide; the plasticizer is one of dibutyl phthalate, dioctyl phthalate and tricresyl phosphate.

10. A method for preparing the high-strength asphalt composite material according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) Weigh by weight: 60-80 parts of matrix asphalt, 5-15 parts of glass fiber, 3-10 parts of nano inorganic filler, 0.5-3 parts of anti-stripping agent, 1-5 parts of plasticizer, and 0.5-1 part of modified antioxidant; (2) Heat the matrix asphalt to 160-180°C, perform ultrasonic treatment, add plasticizer and modified antioxidant, and stir for 10-20 minutes; then add anti-stripping agent, glass fiber and nano inorganic filler, stir at high speed for 30-60 minutes, and cool to room temperature to obtain a high-strength asphalt composite material.

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