Water-damage-resistant composite asphalt concrete and preparation method thereof

Abstract

The invention relates to the technical field of asphalt concrete, and discloses water-damage-resistant composite asphalt concrete and a preparation method thereof. The composite asphalt concrete prepared by the invention is prepared from the following raw materials in parts by weight: 3.5-5.5 parts of matrix asphalt, 0.3-0.5 part of an anti-stripping agent, 85-95 parts of mixed aggregate, 2.5-5.5 parts of mineral powder, 2-4 parts of carbon black and 3-6 parts of modified polyester fibers, the composite asphalt concrete is prepared by taking acidic aggregate as a main raw material, adding asphalt, mineral powder, carbon black, modified polyester fibers and an anti-stripping agent, heating and stirring, wherein the anti-stripping agent and the modified polyester fiber are added, so that the water damage resistance of the composite asphalt concrete can be improved, and the composite asphalt concrete has excellent water erosion resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of asphalt concrete, in particular to a water-damage-resistant composite asphalt concrete and a preparation method thereof. BACKGROUND

[0002] Asphalt concrete is widely used as the core material of modern road engineering due to its excellent mechanical properties, construction convenience and driving comfort. However, under the long-term effects of complex environments (such as rain, freeze-thaw, salt corrosion, etc.) and heavy traffic, water-induced damage caused by water intrusion has become one of the main causes of early damage to asphalt pavement. Water damage is manifested as peeling of the asphalt-aggregate interface, loose mixture, crack propagation and pothole formation, which seriously reduces the service life of the pavement and brings high maintenance costs. In view of this problem, the industry has carried out continuous research around material modification, structure optimization and process innovation, but traditional technologies still face many bottlenecks.

[0003] Currently, there are two main methods to improve the adhesion of asphalt and aggregate: one is to use alkaline aggregate that has good adhesion with asphalt; the other is to take some anti-stripping measures or use anti-stripping agents. These two methods can improve the adhesion of asphalt and aggregate to some extent, but they also have some shortcomings. When using alkaline aggregate, the water stability of asphalt mixture is improved to some extent, but the strength and fatigue resistance of asphalt mixture are reduced. Because the mechanical properties of alkaline aggregate are far inferior to those of acidic aggregate. And the above-mentioned methods of improving the water stability of asphalt mixture also have other shortcomings, such as easy segregation, poor thermal stability, poor durability, increased workload, etc. Therefore, it is of great significance to prepare an asphalt concrete with excellent water damage resistance. SUMMARY

[0004] In order to solve the above technical problems, the present application provides a water-damage-resistant composite asphalt concrete and a preparation method thereof.

[0005] The object of the present application can be achieved by the following technical solutions:

[0006] A water-damage-resistant composite asphalt concrete, comprising the following raw materials by weight: 3.5-5.5 parts of base asphalt, 0.3-0.5 parts of anti-stripping agent, 85-95 parts of mixed aggregate, 2.5-5.5 parts of mineral powder, 2-4 parts of carbon black, and 3-6 parts of modified polyester fiber.

[0007] Further, the mixed aggregate is a mixture of acidic fine aggregate and acidic coarse aggregate.

[0008] Further, the mass ratio of the acid fine aggregate and the acid coarse aggregate is 5-7:3-5, wherein the particle size of the acid fine aggregate is 0.075mm-2.4mm, and the particle size of the coarse aggregate is 2.5mm-15mm;

[0009] Further, the particle size of the mineral powder is 0.075-0.2mm limestone mineral powder.

[0010] The anti-stripping agent is prepared by the following steps:

[0011] Step A1, mixing and stirring imidazole, triethylamine and tetrahydrofuran uniformly, denoted as imidazole solution; mixing and stirring neodecanoyl chloride and tetrahydrofuran uniformly under ice water bath, then slowly adding the imidazole solution, transferring to a 40℃ oil bath pot for stirring for 3.5-4.5h, filtering, rotary evaporation, washing, secondary filtering and drying, to obtain a tert-butyl-imidazole derivative;

[0012] Further, in step A1, the amount ratio of neodecanoyl chloride, tetrahydrofuran and the imidazole solution is 0.11-0.22mol:50mL:50mL.

[0013] Further, in the imidazole solution of step A1, the amount ratio of imidazole, triethylamine and tetrahydrofuran is 0.1-0.2mol:0.11-0.22mol:50mL.

[0014] Step A2, mixing and stirring the tert-butyl-derivative in N,N-dimethylformamide under nitrogen condition, then adding 3-bromo-1-propanol and heating to 60-70℃ for stirring for 24h, reduced pressure distillation, washing and drying, to obtain a quaternary ammonium salt derivative.

[0015] Further, in step A2, the amount ratio of the tert-butyl-derivative, 3-bromo-1-propanol and N,N-dimethylformamide is 0.1-0.2mol:0.1-0.2mol:100mL.

[0016] Step A3, mixing the quaternary ammonium salt derivative and boric acid in toluene uniformly, and heating to 110℃ for constant temperature reflux reaction for 6-8h, and azeotropic distillation, to obtain the anti-stripping agent.

[0017] Further, in step A3, the amount ratio of the quaternary ammonium salt derivative, boric acid and toluene is 0.15-0.3mol:0.05-0.1mol:50mL.

[0018] The modified polyester fiber is prepared by the following steps:

[0019] Step B1, after cutting the polyester fiber into 4-6mm length, washing in acetone, 80g / L sodium hydroxide solution, adjusting pH to neutral, drying, collecting the polyester staple fiber, dispersing the polyester staple fiber in the mixture of ethanol and water again, adding 3-(2,3-epoxypropoxy) propyl trimethoxysilane, adjusting pH to 3-4, refluxing at 65℃ for 5-8h, washing to neutral, drying, and then the epoxidized polyester staple fiber is obtained;

[0020] The hydroxyl polyester staple fiber obtained in step B1

[0021] Further, in step B1, the use amount ratio of polyester fiber, acetone and sodium hydroxide solution is 1g:200mL:200mL.

[0022] Further, in the epoxidized polyester staple fiber in step B1, the use amount ratio of polyester staple fiber, ethanol, water and 3-(2,3-epoxypropoxy) propyl trimethoxysilane is 1g:40mL:20mL:0.1-0.2g.

[0023] Step B2, mixing and stirring the epoxidized polyester staple fiber and p-toluenesulfonic acid in N,N-dimethylformamide, adding double-hexadecyl phosphoric acid, reacting under the condition of nitrogen and 90℃ for 3-5h, filtering, reducing pressure distillation, drying, and then the modified polyester fiber is obtained.

[0024] Further, in step B2, the use amount ratio of epoxidized polyester staple fiber, double-hexadecyl phosphoric acid, p-toluenesulfonic acid and N,N-dimethylformamide is 10g:2-5g:0.2-0.4g:100mL.

[0025] A preparation method of water-damage-resistant composite asphalt concrete comprises the following steps:

[0026] Step S1, weighing the raw materials by weight parts, heating the base asphalt to 170℃, adding the anti-stripping agent, mixing and stirring uniformly, and then the asphalt mixture is obtained.

[0027] Step S2, mixing and stirring the mixed aggregate, mineral powder, carbon black and modified polyester fiber uniformly, adding the asphalt mixture, and stirring uniformly at 160-170℃, and then the water-damage-resistant composite asphalt concrete is obtained.

[0028] The beneficial effects of the present application are as follows:

[0029] The prepared composite asphalt concrete is prepared by adding asphalt, mineral powder, carbon black, modified polyester fiber and anti-stripping agent to the acid aggregate as the main raw material and heating and stirring; the addition of the anti-stripping agent and the modified polyester fiber can improve the water-damage-resistant performance of the composite asphalt concrete, so that the composite asphalt concrete has excellent ability to resist water erosion.

[0030] The anti-stripping agent prepared by the present application can significantly improve the water damage resistance of asphalt concrete, which is due to the synergistic effect between the t-butyl structure, the imidazole quaternary ammonium salt structure and the borate structure in the anti-stripping agent; wherein the t-butyl group is a highly hydrophobic three-dimensional group, and its steric hindrance effect and hydrophobicity can form a "molecular level hydrophobic film" at the asphalt-aggregate interface, thereby effectively blocking water from penetrating into the asphalt-aggregate bonding interface and improving the water damage resistance; the positive charge of the imidazole quaternary ammonium salt structure can produce electrostatic effect with the negative charge on the surface of the acidic aggregate, so that the anti-stripping agent can be firmly adsorbed on the surface of the aggregate to form a "charge bridge", thereby enhancing the adhesion between asphalt and aggregate; meanwhile, the electron-rich property of the imidazole ring can form a coordination bond with the metal ions (such as Ca 2+ 、Al 3+ ) on the surface of the aggregate, passivate the active sites on the surface of the aggregate, reduce the direct contact between water molecules and the aggregate, and further improve the water damage resistance; the dynamic reversible borate structure can react with the hydroxyl groups on the surface of the aggregate to form stable B-O-Si or B-O-Al covalent bonds, thereby significantly enhancing the chemical bonding strength between asphalt and aggregate; when a small amount of water molecules invade, the B-O bond can be temporarily hydrolyzed into boric acid and alcohol; but under dry conditions, the hydrolysis products can be esterified again to restore the bond, which gives the asphalt mixture a certain degree of "self-healing" ability and delays the development of water damage.

[0031] The modified polyester fiber in the present application can significantly improve the water damage resistance through chemical-physical synergistic effect in the matrix, wherein the phosphate group can form a stable phosphate chemical bond with Ca 2+ 、Al 3+ on the surface of the aggregate, anchor the polyester fiber on the surface of the aggregate, form a strong bonding interface of "fiber-aggregate-asphalt", improve the bonding strength between the fiber and the aggregate, and reduce the interface peeling caused by water invasion; the polar end of the phosphate ester is combined with the polar components (such as asphaltene) in asphalt through hydrogen bonding or dipole interaction, while the hydrophobic segment is compatible with the oil phase of asphalt, forming a "amphiphilic interface", thereby enhancing the adhesion between the fiber and the asphalt. In addition, the long-chain alkyl group forms a dense hydrophobic layer on the surface of the fiber through low surface energy characteristics and steric hindrance effect, significantly increases the water contact angle, and inhibits the diffusion of water along the fiber-asphalt interface. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0033] The following examples use fine acidic fine aggregate with a particle size of 0.075 mm-2.4 mm, coarse aggregate with a particle size of 2.5 mm-15 mm, and mineral powder with a particle size of 0.075-0.2 mm limestone mineral powder. The base asphalt is purchased from Maoming Petrochemical 70# base asphalt, with an oil stone ratio of 1:20. The LY asphalt anti-stripping agent is purchased from Hengshui Zerun Lubricating Oil Co., Ltd.

[0034] Example 1: The anti-stripping agent is prepared by the following steps:

[0035] Step A1, 0.1 mol of imidazole, 0.11 mol of triethylamine and 50 mL of tetrahydrofuran are mixed and stirred uniformly, denoted as imidazole solution; 0.11 mol of neodecanoyl chloride and 50 mL of tetrahydrofuran are mixed and stirred uniformly under ice water bath, then 50 mL of the imidazole solution is slowly added, transferred to a 40℃ oil bath pot and stirred for 3.5 h, filtered, rotary evaporated, washed, twice filtered and dried, to obtain a t-butyl-imidazole derivative;

[0036] Step A2, 0.1 mol of the t-butyl-derivative is mixed and stirred uniformly in 100 mL of N,N-dimethylformamide under nitrogen condition, then 0.1 mol of 3-bromo-1-propanol is added and heated to 60℃ for stirring reaction for 24 h, reduced pressure distillation, washing and drying, to obtain a quaternary ammonium salt derivative;

[0037] Step A3, 0.15 mol of the quaternary ammonium salt derivative and 0.05 mol of boric acid are mixed uniformly in 50 mL of toluene and heated to 110℃, constant temperature reflux reaction for 6 h, and azeotropic distillation, to obtain the anti-stripping agent.

[0038] The modified polyester fiber is prepared by the following steps:

[0039] Step B1, 1 g of polyester fiber is cut into 4 mm in length, then sequentially washed in 200 mL of acetone, 200 mL of 80 g / L sodium hydroxide solution, the pH is adjusted to neutral, dried, and the polyester staple fiber is collected, then 1 g of the polyester staple fiber is dispersed in a mixture of 40 mL of ethanol and 20 mL of water, 0.1 g of 3-(2,3-epoxypropoxy) propyl trimethoxysilane is added, the pH is adjusted to 3, and refluxed at 65℃ for 5 h, washed to neutral, and dried, to obtain the epoxidized polyester staple fiber;

[0040] Step B2, 10 g of the epoxidized polyester short fiber and 0.2 g of p-toluenesulfonic acid were mixed and stirred in 100 mL of N,N-dimethylformamide, 2 g of dihexadecyl phosphate was added, and the mixture was reacted at 90°C under nitrogen for 3 h. The mixture was filtered, distilled under reduced pressure, and dried to obtain the modified polyester fiber.

[0041] Example 2: The anti-stripping agent was prepared by the following steps:

[0042] Step A1, 0.15 mol of imidazole, 0.16 mol of triethylamine, and 50 mL of tetrahydrofuran were mixed and stirred to obtain an imidazole solution; 0.16 mol of neodecanoyl chloride and 50 mL of tetrahydrofuran were mixed and stirred in an ice water bath, and then 50 mL of the imidazole solution was slowly added. The mixture was transferred to a 40°C oil bath and stirred for 4 h. The mixture was filtered, rotary evaporated, washed, filtered twice, and dried to obtain a tert-butyl-imidazole derivative;

[0043] Step A2, 0.15 mol of the tert-butyl-derivative was mixed and stirred in 100 mL of N,N-dimethylformamide under nitrogen, and then 0.15 mol of 3-bromo-1-propanol was added. The mixture was heated to 65°C and stirred for 24 h. The mixture was distilled under reduced pressure, washed, and dried to obtain a quaternary ammonium salt derivative;

[0044] Step A3, 0.22 mol of the quaternary ammonium salt derivative and 0.075 mol of boric acid were mixed in 50 mL of toluene and heated to 110°C. The mixture was refluxed for 7 h and then subjected to azeotropic distillation to obtain the anti-stripping agent.

[0045] The modified polyester fiber was prepared by the following steps:

[0046] Step B1, 1 g of polyester fiber was cut into 5 mm lengths, and then sequentially washed in 200 mL of acetone, 200 mL of 80 g / L sodium hydroxide solution, and deionized water to adjust the pH to neutral. The polyester short fiber was collected and then dispersed in a mixture of 40 mL of ethanol and 20 mL of water. 0.15 g of 3-(2,3-epoxypropoxy)propyl trimethoxysilane was added, and the pH was adjusted to 3.5. The mixture was refluxed at 65°C for 6 h, washed to neutral, and dried to obtain an epoxidized polyester short fiber;

[0047] Step B2, 10 g of the epoxidized polyester short fiber and 0.3 g of p-toluenesulfonic acid were mixed and stirred in 100 mL of N,N-dimethylformamide, 3.5 g of dihexadecyl phosphate was added, and the mixture was reacted at 90°C under nitrogen for 4 h. The mixture was filtered, distilled under reduced pressure, and dried to obtain the modified polyester fiber.

[0048] Example 3: The anti-stripping agent was prepared by the following steps:

[0049] Step A1, 0.2 mol imidazole, 0.22 mol triethylamine and 50 mL tetrahydrofuran were mixed and stirred uniformly, denoted as imidazole solution; 0.22 mol neodecanoyl chloride and 50 mL tetrahydrofuran were mixed and stirred uniformly under ice water bath, then 50 mL imidazole solution was slowly added, transferred to 40℃ oil bath pot and stirred for 4.5 h, filtered, rotary evaporated, washed, twice filtered and dried, to obtain tert-butyl-imidazole derivative;

[0050] Step A2, 0.2 mol tert-butyl-derivative was mixed and stirred uniformly in 100 mL N,N-dimethylformamide under nitrogen condition, then 0.2 mol 3-bromo-1-propanol was added and heated to 70℃ for stirring reaction for 24 h, distilled under reduced pressure, washed and dried, to obtain quaternary ammonium salt derivative;

[0051] Step A3, 0.3 mol quaternary ammonium salt derivative and 0.1 mol boric acid were mixed uniformly in 50 mL toluene and heated to 110℃, constant temperature reflux reaction was carried out for 8 h, and azeotropic distillation was carried out, to obtain anti-stripping agent.

[0052] The modified polyester fiber was prepared by the following steps:

[0053] Step B1, 1 g polyester fiber was cut into 6 mm length, then sequentially washed in 200 mL acetone, 200 mL 80 g / L sodium hydroxide solution, pH was adjusted to neutral, dried, and polyester staple fiber was collected, then 1 g polyester staple fiber was dispersed in 40 mL ethanol and 20 mL water mixture, 0.2 g 3-(2,3-epoxypropoxy) propyl trimethoxysilane was added, pH was adjusted to 4, refluxed at 65℃ for 8 h, washed to neutral, and dried, to obtain epoxidized polyester staple fiber;

[0054] Step B2, 10 g epoxidized polyester staple fiber and 0.4 g p-toluenesulfonic acid were mixed and stirred uniformly in 100 mL N,N-dimethylformamide, 5 g dihexadecyl phosphate was added, reaction was carried out under nitrogen, 90℃ for 5 h, filtered, distilled under reduced pressure and dried, to obtain modified polyester fiber.

[0055] Example 4: a preparation method of water-resistant composite asphalt concrete comprises the following steps:

[0056] Step S1, raw materials were weighed by weight parts, 3.5 parts of base asphalt was heated to 170℃, 0.3 parts of anti-stripping agent prepared in example 1 was added and mixed and stirred uniformly, to obtain asphalt mixture;

[0057] Step S2, the acid fine aggregate and acid coarse aggregate are mixed uniformly according to a mass ratio of 5:5, to obtain a mixed aggregate; 85 parts of the mixed aggregate, 2.5 parts of the mineral powder, 2 parts of the carbon black and 3 parts of the modified polyester fiber prepared in Example 1 are mixed and stirred uniformly, and the asphalt mixture is added, and then stirred uniformly at 160℃, to obtain the water damage resistant composite asphalt concrete.

[0058] Example 5: A preparation method of a water damage resistant composite asphalt concrete comprises the following steps:

[0059] Step S1, the raw materials are weighed according to the weight parts, 4.5 parts of the base asphalt is heated to 170℃, and 0.4 parts of the anti-stripping agent prepared in Example 2 is added and stirred uniformly, to obtain the asphalt mixture;

[0060] Step S2, the acid fine aggregate and acid coarse aggregate are mixed uniformly according to a mass ratio of 6:4, to obtain a mixed aggregate; 90 parts of the mixed aggregate, 4 parts of the mineral powder, 3 parts of the carbon black and 4.5 parts of the modified polyester fiber prepared in Example 2 are mixed and stirred uniformly, and the asphalt mixture is added, and then stirred uniformly at 165℃, to obtain the water damage resistant composite asphalt concrete.

[0061] Example 6: A preparation method of a water damage resistant composite asphalt concrete comprises the following steps:

[0062] Step S1, the raw materials are weighed according to the weight parts, 5.5 parts of the base asphalt is heated to 170℃, and 0.5 parts of the anti-stripping agent prepared in Example 3 is added and stirred uniformly, to obtain the asphalt mixture;

[0063] Step S2, the acid fine aggregate and acid coarse aggregate are mixed uniformly according to a mass ratio of 7:3, to obtain a mixed aggregate; 95 parts of the mixed aggregate, 5.5 parts of the mineral powder, 4 parts of the carbon black and 6 parts of the modified polyester fiber prepared in Example 3 are mixed and stirred uniformly, and the asphalt mixture is added, and then stirred uniformly at 170℃, to obtain the water damage resistant composite asphalt concrete.

[0064] Comparative Example 1: The comparative example is a composite asphalt concrete, which is different from Example 6 in that the LY asphalt anti-stripping agent is used instead of the anti-stripping agent prepared in Example 3, and the rest are the same.

[0065] Comparative Example 2: The comparative example is a composite asphalt concrete, which is different from Example 6 in that the polyester fiber is used instead of the modified polyester fiber prepared in Example 3, and the rest are the same.

[0066] Comparative Example 3: The comparative example is a composite asphalt concrete, which is different from Example 6 in that the LY asphalt anti-stripping agent is used instead of the anti-stripping agent prepared in Example 3, and the polyester fiber is used instead of the modified polyester fiber prepared in Example 3, and the rest are the same.

[0067] The composite asphalt concrete prepared in Examples 4-6 and Comparative Examples 1-3 was subjected to performance tests:

[0068] Stability test: the composite asphalt concrete prepared in Examples and Comparative Examples was prepared into standard asphalt Marshall test pieces, and then subjected to Marshall stability and immersion Marshall stability tests. In preparing the standard asphalt Marshall test pieces, the requirements of T0702-2011 Asphalt Mixture Test Piece Preparation Method (Compaction Method) in JTG E20-2011 Highway Engineering Asphalt and Asphalt Mixture Test Procedures were referred to, and specifically, the diameter of the standard asphalt Marshall test pieces was 101.6 mm, and the height was 63.5±1.2 mm. The Marshall stability and immersion Marshall residual stability (residual stability) tests were performed according to the requirements of JTG E20-2011 Highway Engineering Asphalt and Asphalt Mixture Test Procedures;

[0069] Adhesion test: the water boiling method was used to perform the asphalt mortar (i.e. the mixture of the base asphalt in the application and the mineral powder, carbon black, anti-stripping agent and modified polyester fiber) and mixed aggregate adhesion test according to the requirements of T0616-1993 in JTG E20-2011 Highway Engineering Asphalt and Asphalt Mixture Test Procedures;

[0070] The test results are shown in Table 1:

[0071] Table 1: Performance test results

[0072] Marshall stability (kN) Residual stability (%) Adhesion rating Example 4 11.65 90.83 5 Example 5 12.12 91.26 5 Example 6 12.68 91.64 5 Comparative Example 1 10.13 85.32 4 Comparative Example 2 10.05 85.06 4 Comparative Example 3 8.83 80.28 3

[0073] As can be seen from Table 1, after the stability test, the Marshall stability of the composite asphalt concrete prepared in the application was in the range of (11.65-12.68) kN, and the residual stability was in the range of (90.83-91.64)%, indicating that the composite asphalt concrete had excellent water damage resistance. After the adhesion test, the adhesion grade was 5, indicating that the composite asphalt concrete had excellent adhesion. The above content is only an example and description of the concept of the application, and those skilled in the art can make various modifications or supplements or use similar ways to replace the described specific examples, as long as they do not deviate from the scope defined by the concept of the application, and should belong to the protection scope of the application.

Claims

1. A water-damage resistant composite asphalt concrete, characterized in that: The raw materials include the following parts by weight: 3.5-5.5 parts of base asphalt, 0.3-0.5 parts of anti-stripping agent, 85-95 parts of mixed aggregate, 2.5-5.5 parts of mineral powder, 2-4 parts of carbon black, and 3-6 parts of modified polyester fiber; The mixed aggregate is a mixture of acidic fine aggregate and acidic coarse aggregate; The particle size of the mineral powder is 0.075-0.2mm limestone mineral powder; The anti-stripping agent is prepared by reacting a quaternary ammonium salt derivative with boric acid, the quaternary ammonium salt derivative is prepared by reacting a tert-butyl-derivative with 3-bromo-1-propanol, and the tert-butyl-imidazole derivative is prepared by reacting imidazole with neodecanoyl chloride; The modified polyester fiber is prepared by treating sheared polyester staple fibers with a silane coupling agent and then reacting with dihexadecyl phosphoric acid.

2. The water-damage resistant composite asphalt concrete according to claim 1, characterized in that: The mass ratio of the acidic fine aggregate to the acidic coarse aggregate is 5-7:3-5, the particle size of the acidic fine aggregate is 0.075mm-2.4mm, and the particle size of the coarse aggregate is 2.5mm-15mm.

3. The water-damage resistant composite asphalt concrete according to claim 1, characterized in that: The anti-stripping agent is prepared by the following steps: Step A1: Mix imidazole, triethylamine, and tetrahydrofuran and stir them uniformly to obtain an imidazole solution; mix neodecanoyl chloride and tetrahydrofuran in an ice-water bath and stir them uniformly, then slowly add the imidazole solution, transfer to a 40°C oil bath, and stir for 3.5-4.5 hours. Filter, rotary evaporate, wash, filter twice, and dry to obtain a tert-butyl imidazole derivative; Step A2: Under nitrogen, the tert-butyl derivative is mixed and stirred in N,N-dimethylformamide, and then 3-bromo-1-propanol is added. The mixture is heated to 60-70° C. and stirred for 24 hours. The mixture is distilled under reduced pressure, washed, and dried to obtain a quaternary ammonium salt derivative. Step A3: uniformly mix the quaternary ammonium salt derivative and boric acid in toluene, heat to 110° C., reflux at a constant temperature for 6-8 hours, and perform azeotropic distillation to obtain an anti-stripping agent.

4. The water-damage resistant composite asphalt concrete according to claim 3, characterized in that: In step A1, the usage ratio of neodecanoyl chloride, tetrahydrofuran and imidazole solution is 0.11-0.22 mol:50 mL:50 mL, and the usage ratio of imidazole, triethylamine and tetrahydrofuran in the imidazole solution is 0.1-0.2 mol:0.11-0.22 mol:50 mL.

5. The water-damage resistant composite asphalt concrete according to claim 3, characterized in that: In step A2, the ratio of the tert-butyl derivative, 3-bromo-1-propanol and N,N-dimethylformamide is 0.1-0.2 mol:0.1-0.2 mol:100 mL.

6. The water-damage resistant composite asphalt concrete according to claim 3, characterized in that: In step A3, the usage ratio of the quaternary ammonium salt derivative, boric acid and toluene is 0.15-0.3 mol:0.05-0.1 mol:50 mL.

7. The water-damage resistant composite asphalt concrete according to claim 1, characterized in that: The modified polyester fiber is prepared by the following steps: Step B1, after cutting the polyester fiber into a length of 4-6 mm, washing it in acetone and 80 g / L sodium hydroxide solution in sequence, adjusting the pH to neutral, drying, collecting the polyester staple fibers, and then redispersing the polyester staple fibers in a mixture of ethanol and water, adding 3-(2,3-epoxypropoxy)propyltrimethoxysilane, adjusting the pH to 3-4, reflux at 65° C. for 5-8 hours, washing until neutral, and drying to obtain epoxidized polyester staple fibers; Step B2: Mix the epoxidized polyester staple fiber and p-toluenesulfonic acid in N,N-dimethylformamide and stir evenly, add dihexadecylphosphoric acid, react under nitrogen at 90° C. for 3-5 hours, filter, distill under reduced pressure, and dry to obtain the modified polyester fiber.

8. The water-damage resistant composite asphalt concrete according to claim 7, characterized in that: In step B1, the amount ratio of polyester fiber, acetone and sodium hydroxide solution is 1 g: 200 mL: 200 mL. In the epoxidized polyester staple fiber, the amount ratio of polyester staple fiber, ethanol, water and 3-(2,3-epoxypropoxy)propyltrimethoxysilane is 1 g: 40 mL: 20 mL: 0.1-0.2 g.

9. The water-damage resistant composite asphalt concrete according to claim 7, characterized in that: In step B2, the usage ratio of epoxidized polyester staple fiber, dihexadecyl phosphoric acid, p-toluenesulfonic acid and N,N-dimethylformamide is 10 g:2-5 g:0.2-0.4 g:100 mL.

10. A method for preparing the water-damage resistant composite asphalt concrete according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step S1, weighing raw materials according to weight, heating the base asphalt to 170° C., adding an anti-stripping agent and mixing and stirring uniformly to obtain an asphalt mixture; Step S2: Mix the mixed aggregate, mineral powder, carbon black and modified polyester fiber and stir them evenly, add the asphalt mixture, and stir them evenly at 160-170° C. to obtain water-damage-resistant composite asphalt concrete.