Anti-aging reinforced asphalt mixture and preparation method thereof

Abstract

The invention discloses an anti-aging reinforced asphalt mixture and a preparation method thereof, and relates to the technical field of buildings. Flake graphite is modified by using a ball milling process, sodium lignin sulfonate is used as a dispersion medium, graphite forms flake graphene, the flake graphene has a huge specific surface area and high surface activity, and then asphalt filler can realize aging resistance of asphalt, so that the anti-aging performance of the asphalt is improved, and the service life of the asphalt is prolonged. Then dihexylenetriamine, silicon dioxide and modified graphite are subjected to a cross-linking reaction to prepare low-density aerogel, and the low-density aerogel can play a role in a framework in an asphalt matrix and can also be used for isolating harms caused by aging factors such as oxygen and moisture; meanwhile, the graphene exposed on the hole wall can serve as a core site of silicate which is one of asphalt filler components, formed hydrated crystals fill pores and cracks of the mixture, and a template effect is achieved, so that the strength of a matrix is improved.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, in particular to an anti-aging enhanced asphalt mixture and a preparation method thereof. Background Art

[0002] By the end of 2023, the mileage of Class IV and above highways in China will be 5.2701 million kilometers, of which asphalt pavements with excellent road performance are the main ones. Usually, the design service life of highways is generally stipulated as 15 years, but the actual service life of asphalt pavements is far from its original design requirements. If the durability of asphalt pavements can be improved, the frequency of road maintenance and road reconstruction will be significantly reduced. my country has a vast territory and diverse climates. Asphalt pavements are subjected to the coupling effects of temperature, oxygen, water vapor, ultraviolet rays and other factors and the repeated rolling of complex vehicle loads for a long time, which will cause serious and irreversible aging of asphalt materials, reduce the bonding strength between asphalt and aggregates, and cause asphalt mixtures to become loose, and eventually cracks, potholes and other diseases will appear, which will shorten the service life of asphalt pavements and even seriously endanger driving safety. However, asphalt and asphalt mixtures continue to age and their performance declines during production, transportation, construction and later operation stages due to the combined effects of temperature, light, rain and vehicle axle loads. With the rapid development of science and technology and the continuous maturity of construction technology, high-quality asphalt pavement must not only meet the requirements of road performance and operating life. Summary of the invention

[0003] The object of the present invention is to provide an aging-resistant enhanced asphalt mixture and a preparation method thereof, so as to solve the problems existing in the prior art.

[0004] In order to solve the above technical problems, the present invention provides the following technical solution: an aging-resistant enhanced asphalt mixture, wherein the aging-resistant enhanced asphalt mixture is prepared by mixing modified graphite with an asphalt mixture.

[0005] Furthermore, the modified graphite is prepared by subjecting flake graphite to a ball-milling modification treatment.

[0006] Furthermore, the asphalt mixture is prepared by mixing asphalt and concrete.

[0007] Furthermore, a method for preparing an aging-resistant enhanced asphalt mixture comprises the following preparation steps:

[0008] (1) flake graphite and 30 wt% hydrogen peroxide are mixed uniformly, concentrated nitric acid is added, and the mixture is placed in an ice water bath, stirred at 200-400 rpm until the reaction is smooth, reacted at 18-25° C. for 40-90 min, washed with a 30 wt% nitric acid aqueous solution for 3-6 times, and then a 70 wt% acetic acid aqueous solution is added, stirred at 100-200 rpm for 10-40 min, filtered, and the solid is taken, washed with deionized water for 3-6 times, then mixed with sodium lignin sulfonate, epoxy triacetate, and deionized water, stirred at 8000-15000 rpm for 20-50 min, and then ball milled, centrifuged, and a modified graphite dispersion is obtained;

[0009] (2) Mixing tetraethyl orthosilicate and anhydrous ethanol, stirring at 60-120 rpm for 5-20 min, adjusting the solution pH to 2.5-3.5 with dilute hydrochloric acid, continuing stirring for 10-30 min, adding modified graphite dispersion and dihexylenetriamine, adjusting the solution pH to 7-8 with ammonia water, standing at 40-80° C. for 4-8 h, then immersing in anhydrous ethanol, aging for 48 h, taking out, and then immersing in n-hexane, standing for 48 h, taking out, and drying at 60-130° C. for 2-6 h to obtain a low-density aerogel;

[0010] (3) Cut the low-density aerogel into blocks, and then mix it with No. 90 base asphalt, tris[2,4-di-tert-butylphenyl] phosphite, and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacic acid ester, heat it to 140-180°C, stir it at 60-200rpm for 4-8h, add modified graphite dispersion, silicate cement, limestone with a specification of 10-20mm, limestone with a specification of 1-10mm, fly ash, sulfur, terpene resin, and acetone, stir it at 20-30Hz and 100-200rpm for 30-50min, and obtain an aging-resistant reinforced asphalt mixture.

[0011] Furthermore, the process parameters of the ball milling in step (1) are as follows: the ball milling medium is agate balls, the ball-to-material ratio is 10:1, the rotation speed is 1350 rpm, and the time is 1.5 to 3 hours.

[0012] Furthermore, the centrifugal speed in step (1) is 500-900 rpm and the time is 30-70 min.

[0013] Furthermore, the mass ratio of the flake graphite, 30 wt% hydrogen peroxide, concentrated nitric acid, 70 wt% acetic acid aqueous solution, sodium lignin sulfonate, epoxy triacetate, and deionized water in step (1) is:

[0014] 1~7:1:10~16:3~10:3~10:20~50:500.

[0015] Furthermore, in step (2), the mass ratio of tetraethyl orthosilicate, anhydrous ethanol, modified graphite dispersion and dihexylenetriamine is 1-6:2-10:10-30:0.1-0.5.

[0016] Furthermore, the size of the block in step (3) is 0.1 cm×0.1 cm×0.5 cm.

[0017] Furthermore, the mass ratio of the low-density aerogel, No. 90 matrix asphalt, tris[2,4-di-tert-butylphenyl]phosphite, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacic acid ester, modified graphite dispersion, silicate cement, limestone with a specification of 10 to 20 mm, limestone with a specification of 1 to 10 mm, fly ash, sulfur, terpene resin, and acetone in step (3) is 1 to 5:20 to 50:3:3:1 to 10:10:25 to 70:14:5:1 to 10:2:10.

[0018] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0019] The asphalt mixture of the invention is prepared by mixing modified graphite with the asphalt mixture to achieve the effects of aging resistance and high strength.

[0020] Firstly, the flake graphite is modified by ball milling process, and sodium lignin sulfonate is used as the dispersion medium. With the assistance of surfactant, the surface tension of the solution and the large volume effect can increase the distance between adjacent graphite sheets, provide more exfoliation sites and prevent graphite agglomeration. Then, the graphite is transformed from a three-dimensional structure to a two-dimensional state through mechanical force, thereby achieving exfoliation and forming flaky graphene. The obtained graphene has a huge specific surface area and high surface activity. Then, as one of the fillers, it can inhibit the transformation of aromatic components in asphalt into colloids, fundamentally hinder the thermal oxidation conversion between components, thereby achieving the aging resistance of asphalt and enhancing the strength of asphalt.

[0021] Secondly, dihexylenetriamine is used to form multi-point cross-linking with silica and modified graphite through its amino group. After dehydration condensation, the nano-silica particles aggregate into primary particles, and the primary particles further grow to form secondary particles. The cross-linking of the secondary particles and the graphite sheets forms a three-dimensional skeleton structure. The long molecular chain of dihexylenetriamine makes the cross-linking points dispersed, and the pore size increases accordingly, thereby obtaining a low-density aerogel, which can not only play a skeleton role in the asphalt matrix and enhance the stability of the antioxidant, but also isolate the harm of aging factors such as oxygen and moisture, thereby further enhancing the mechanical properties and anti-aging properties of the asphalt; at the same time, the exposed graphene on the pore wall can act as the nuclear site of silicate, one of the components of the asphalt filler, and the formed hydrated crystals fill the pores and cracks of the mixture, and to a certain extent can hinder the generation of cracks, play a template effect, thereby increasing the strength of the matrix. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In order to more clearly illustrate the method provided by the present invention, the following examples are used to describe in detail the various index testing methods of the aging-resistant enhanced asphalt mixture prepared in the following examples are as follows:

[0024] Anti-aging: The embodiment and the comparative example of the same size were subjected to a rotary film oven aging test at an aging temperature of 120° C. for 200 min. The softening point and needle penetration were tested according to the Ministry of Transport industry standard JTGE20.

[0025] Strength: The asphalt mixtures of the examples and comparative examples were made into specimens with a size of 100 mm×100 mm×100 mm, and the compressive strength of the specimens at different ages was tested with reference to GB / T50081.

[0026] Example 1

[0027] (1) Graphite flakes and 30 wt% hydrogen peroxide were mixed evenly, concentrated nitric acid was added, and the mixture was placed in an ice water bath and stirred at 200 rpm until the reaction was smooth. The mixture was reacted at 18°C ​​for 40 min, and the mixture was washed three times with a 30 wt% nitric acid aqueous solution. Then, a 70 wt% acetic acid aqueous solution was added and stirred at 100 rpm for 10 min. The mixture was filtered, and the solid was washed three times with deionized water. Then, the solid was mixed with sodium lignin sulfonate, epoxy triacetate, and deionized water, and stirred at 8000 rpm for 20 min. in, and then ball milling treatment, the process parameters are: the ball milling medium is agate ball, the ball-to-material ratio is 10:1, the rotation speed is 1350rpm, the time is 1.5h, and the centrifugation is performed, the rotation speed is 500rpm, the time is 30min, and the modified graphite dispersion is obtained; the mass ratio of the flake graphite, 30wt% hydrogen peroxide, concentrated nitric acid, 70wt% acetic acid aqueous solution, sodium lignin sulfonate, epoxy triacetate, and deionized water is 1:1:10:3:3:20:500;

[0028] (2) Mixing tetraethyl orthosilicate and anhydrous ethanol, stirring at 60 rpm for 5 min, adjusting the solution pH to 2.5 with dilute hydrochloric acid, continuing stirring for 10 min, adding modified graphite dispersion and dihexylene triamine, adjusting the solution pH to 7 with aqueous ammonia, standing at 40° C. for 4 h, then immersing in anhydrous ethanol, aging for 48 h, taking out, and then immersing in n-hexane, standing for 48 h, taking out, and drying at 60° C. for 2 h to obtain a low-density aerogel; the mass ratio of tetraethyl orthosilicate, anhydrous ethanol, modified graphite dispersion, and dihexylene triamine is 1:2:10:0.1;

[0029] (3) The low-density aerogel was cut into blocks with a size of 0.1 cm × 0.1 cm × 0.5 cm, and then mixed with No. 90 matrix asphalt, tris[2,4-di-tert-butylphenyl]phosphite, and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacic acid ester, heated to 140 °C, stirred at 60 rpm for 4 h, and modified graphite dispersion, silicate cement, 10 mm limestone, 1 mm limestone, fly ash, sulfur, terpene resin, and acetone were added and stirred at 20 Hz. , stirring at 100rpm for 30min to obtain an aging-resistant enhanced asphalt mixture; the mass ratios of the low-density aerogel, No. 90 matrix asphalt, tris[2,4-di-tert-butylphenyl] phosphite, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacic acid ester, modified graphite dispersion, Portland cement, 10mm limestone, 1mm limestone, fly ash, sulfur, terpene resin, and acetone are 1:20:3:3:1:10:25:14:5:1:2:10.

[0030] Example 2

[0031] (1) Graphite flakes and 30 wt% hydrogen peroxide were mixed evenly, concentrated nitric acid was added, and the mixture was placed in an ice water bath and stirred at 300 rpm until the reaction was smooth. The mixture was reacted at 22°C for 60 min, and washed with 30 wt% nitric acid aqueous solution for 5 times. Then, 70 wt% acetic acid aqueous solution was added and stirred at 150 rpm for 25 min. The mixture was filtered and the solid was washed with deionized water for 5 times. Then, the solid was mixed with sodium lignin sulfonate, epoxy triacetate, and deionized water and stirred at 12000 rpm for 3 5min, and then ball milling, the process parameters are as follows: the ball milling medium is agate ball, the ball-to-material ratio is 10:1, the rotation speed is 1350rpm, the time is 2h, and the centrifugation is performed, the rotation speed is 700rpm, the time is 50min, and the modified graphite dispersion is obtained; the mass ratio of the flake graphite, 30wt% hydrogen peroxide, concentrated nitric acid, 70wt% acetic acid aqueous solution, sodium lignin sulfonate, epoxy triacetate, and deionized water is 4:1:12:7:6:30:500;

[0032] (2) Mixing tetraethyl orthosilicate and anhydrous ethanol, stirring at 90 rpm for 12 min, adjusting the solution pH to 3 with dilute hydrochloric acid, continuing stirring for 20 min, adding modified graphite dispersion and dihexylene triamine, adjusting the solution pH to 7.5 with aqueous ammonia, standing at 60° C. for 6 h, then immersing in anhydrous ethanol, aging for 48 h, taking out, and then immersing in n-hexane, standing for 48 h, taking out, and drying at 90° C. for 4 h to obtain a low-density aerogel; the mass ratio of tetraethyl orthosilicate, anhydrous ethanol, modified graphite dispersion, and dihexylene triamine is 4:7:20:0.3;

[0033] (3) The low-density aerogel was cut into blocks with a size of 0.1 cm × 0.1 cm × 0.5 cm, and then mixed with No. 90 matrix asphalt, tris[2,4-di-tert-butylphenyl]phosphite, and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacic acid ester, heated to 160°C, stirred at 140 rpm for 6 h, and modified graphite dispersion, silicate cement, 15 mm limestone, 6 mm limestone, fly ash, sulfur, terpene resin, and acetone were added and stirred at 25 Hz. , stirring at 150rpm for 40min to obtain an aging-resistant enhanced asphalt mixture; the mass ratios of the low-density aerogel, No. 90 matrix asphalt, tris[2,4-di-tert-butylphenyl] phosphite, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacic acid ester, modified graphite dispersion, Portland cement, 15mm limestone, 6mm limestone, fly ash, sulfur, terpene resin, and acetone are 3:35:3:3:6:10:50:14:5:6:2:10.

[0034] Example 3

[0035] (1) Graphite flakes and 30 wt% hydrogen peroxide were mixed evenly, concentrated nitric acid was added, and the mixture was placed in an ice water bath and stirred at 400 rpm until the reaction was smooth. The mixture was reacted at 25°C for 90 min, and the mixture was washed with a 30 wt% nitric acid aqueous solution for 6 times. Then, a 70 wt% acetic acid aqueous solution was added and stirred at 200 rpm for 40 min. The mixture was filtered and the solid was washed with deionized water for 6 times. Then, the solid was mixed with sodium lignin sulfonate, epoxy triacetate, and deionized water and stirred at 15000 rpm for 50 min. min, and then ball milling treatment, the process parameters are as follows: the ball milling medium is agate balls, the ball-to-material ratio is 10:1, the rotation speed is 1350rpm, the time is 3h, and the centrifugation is performed, the rotation speed is 900rpm, the time is 70min, and the modified graphite dispersion is obtained; the mass ratio of the flake graphite, 30wt% hydrogen peroxide, concentrated nitric acid, 70wt% acetic acid aqueous solution, sodium lignin sulfonate, epoxy triacetate, and deionized water is 7:1:16:10:10:50:500;

[0036] (2) Mixing tetraethyl orthosilicate and anhydrous ethanol, stirring at 120 rpm for 20 min, adjusting the solution pH to 3.5 with dilute hydrochloric acid, continuing stirring for 30 min, adding modified graphite dispersion and dihexylene triamine, adjusting the solution pH to 8 with aqueous ammonia, standing at 80° C. for 8 h, then immersing in anhydrous ethanol, aging for 48 h, taking out, and then immersing in n-hexane, standing for 48 h, taking out, and drying at 130° C. for 6 h to obtain a low-density aerogel; the mass ratio of tetraethyl orthosilicate, anhydrous ethanol, modified graphite dispersion, and dihexylene triamine is 6:10:30:0.5;

[0037] (3) The low-density aerogel was cut into blocks with a size of 0.1 cm × 0.1 cm × 0.5 cm, and then mixed with No. 90 matrix asphalt, tris[2,4-di-tert-butylphenyl]phosphite, and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacic acid ester, heated to 180°C, stirred at 200 rpm for 8 h, and modified graphite dispersion, silicate cement, 20 mm limestone, 10 mm limestone, fly ash, sulfur, terpene resin, and acetone were added, and the mixture was stirred at 30 Hz, Stir at 200rpm for 50min to obtain an aging-resistant enhanced asphalt mixture; the mass ratios of the low-density aerogel, No. 90 base asphalt, tris[2,4-di-tert-butylphenyl] phosphite, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacic acid ester, modified graphite dispersion, Portland cement, 20mm limestone, 10mm limestone, fly ash, sulfur, terpene resin and acetone are 5:50:3:3:10:10:70:14:5:10:2:10.

[0038] Comparative Example 1

[0039] The difference between Comparative Example 1 and Example 2 is that step (1) is different. Step (1) is changed to: flake graphite and 30wt% hydrogen peroxide are mixed evenly, concentrated nitric acid is added, placed in an ice water bath, stirred at 300rpm until the reaction is smooth, reacted at 22°C for 60min, washed with 30wt% nitric acid aqueous solution 5 times, and then added with 70wt% acetic acid aqueous solution, stirred at 150rpm for 25min, filtered, and the solid was taken, washed with deionized water 5 times, and then mixed with deionized water. The mixture was stirred at 12000rpm for 35min, and then ball milling was performed, wherein the process parameters were as follows: the ball milling medium was agate balls, the ball-to-material ratio was 10:1, the rotation speed was 1350rpm, and the time was 2h; after centrifugation, the rotation speed was 700rpm, and the time was 50min, to obtain a modified graphite dispersion; the mass ratio of the flake graphite, 30wt% hydrogen peroxide, concentrated nitric acid, 70wt% acetic acid aqueous solution, and deionized water was 4:1:12:7:500; and the remaining steps were the same as in Example 2.

[0040] Comparative Example 2

[0041] The difference between Comparative Example 2 and Example 2 is that step (1) is different. Step (1) is changed to: mix flake graphite and 30wt% hydrogen peroxide evenly, add concentrated nitric acid, place in an ice water bath, stir at 300rpm until the reaction is smooth, react at 22°C for 60min, wash with 30wt% nitric acid aqueous solution 5 times, then add 70wt% acetic acid aqueous solution, stir at 150rpm for 25min, filter, take solid, wash with deionized water 5 times, then mix with sodium lignin sulfonate, epoxy triacetate, and deionized water, stir at 12000rpm for 35min, centrifuge at a speed of 700rpm for 50min, and obtain a modified graphite dispersion; the mass ratio of the flake graphite, 30wt% hydrogen peroxide, concentrated nitric acid, 70wt% acetic acid aqueous solution, sodium lignin sulfonate, epoxy triacetate, and deionized water is 4:1:12:7:6:30:500; the remaining steps are the same as Example 2.

[0042] Comparative Example 3

[0043] The difference between Comparative Example 3 and Example 2 is that step (2) is different. Step (2) is changed to: mix tetraethyl orthosilicate and anhydrous ethanol, stir at 90rpm for 12min, adjust the pH of the solution to 3 with dilute hydrochloric acid, continue stirring for 20min, add modified graphite dispersion, adjust the pH of the solution to 7.5 with ammonia water, stand at 60°C for 6h, then immerse in anhydrous ethanol, age for 48h, take out, immerse in n-hexane, stand for 48h, take out, and dry at 90°C for 4h to obtain a low-density aerogel; the mass ratio of tetraethyl orthosilicate, anhydrous ethanol and modified graphite dispersion is 4:7:20; the remaining steps are the same as Example 2.

[0044] Comparative Example 4

[0045] The difference between Comparative Example 4 and Example 2 is that step (2) is different, and step (2) is changed to: the modified graphite dispersion and dihexylene triamine are mixed, the pH of the solution is adjusted to 7.5 with ammonia water, and the mixture is allowed to stand for 6 hours at 60°C, and then immersed in anhydrous ethanol, aged for 48 hours, taken out, immersed in n-hexane, allowed to stand for 48 hours, taken out, and dried at 90°C for 4 hours to obtain a low-density aerogel; the mass ratio of the modified graphite dispersion and dihexylene triamine is 20:0.3; the remaining steps are the same as those in Example 2.

[0046] Comparative Example 5

[0047] The difference between Comparative Example 5 and Example 2 is that there is no step (2), and step (3) is changed to: No. 90 base asphalt, tris [2,4-di-tert-butylphenyl] phosphite, and bis (2,2,6,6-tetramethyl-4-piperidinyl) sebacic acid ester are mixed, the temperature is raised to 160 ° C, and stirred at 140 rpm for 6 hours, and modified graphite dispersion, silicate cement, 15 mm limestone, 6 mm limestone, fly ash, sulfur, terpene resin, acetone are added, and the mixture is stirred at 25 Hz and 150 r pm and stir for 40 minutes to obtain an aging-resistant enhanced asphalt mixture; the mass ratio of No. 90 base asphalt, tris[2,4-di-tert-butylphenyl] phosphite, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacic acid ester, modified graphite dispersion, silicate cement, 15mm limestone, 6mm limestone, fly ash, sulfur, terpene resin and acetone is 35:3:3:6:10:50:14:5:6:2:10; the remaining steps are the same as those in Example 2.

[0048] Comparative Example 6

[0049] The difference between Comparative Example 6 and Example 2 is that step (3) is different. Step (3) is changed to: the low-density aerogel is cut into blocks with a specification of 0.1 cm×0.1 cm×0.5 cm, and then mixed with No. 90 matrix asphalt, tris[2,4-di-tert-butylphenyl]phosphite, and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacic acid ester, heated to 160°C, stirred at 140rpm for 6h, and silicate cement, limestone with a specification of 15mm, limestone with a specification of 6mm, fly ash, sulfur, terpene resin Fat and acetone are stirred at 25Hz and 150rpm for 40min to obtain an aging-resistant enhanced asphalt mixture; the mass ratio of the low-density aerogel, No. 90 matrix asphalt, tris[2,4-di-tert-butylphenyl] phosphite, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacic acid ester, Portland cement, limestone with a specification of 15mm, limestone with a specification of 6mm, fly ash, sulfur, terpene resin and acetone is 3:35:3:3:10:50:14:5:6:2:10; the remaining steps are the same as those in Example 2.

[0050] Effect example

[0051] Table 1 below shows the performance analysis results of the aging-resistant enhanced asphalt mixtures using Examples 1 to 3 of the present invention and Comparative Examples 1 to 6.

[0052] Table 1

[0053]

[0054]

[0055] From the comparison of the experimental data of the embodiment and the comparative example in Table 1, it can be found that the present invention utilizes ball milling process to modify the flake graphite, adopts sodium lignin sulfonate as the dispersion medium, and with the auxiliary action of surfactant, the distance between adjacent graphite sheets becomes larger, more stripping sites are provided and graphite agglomeration is prevented, and then the graphite is transformed from a three-dimensional structure to a two-dimensional state through mechanical force to form flaky graphene, and the obtained graphene is endowed with a huge specific surface area and a high surface activity, and then as one of the fillers, it can inhibit the transformation of aromatic components in asphalt into colloids, fundamentally hinder the thermal oxygen conversion between components, thereby achieving the aging resistance of asphalt and enhancing the strength of asphalt; then, dihexylene triamine is used with silicon dioxide and modified stone to form a two-dimensional graphene. The ink undergoes multi-point cross-linking, and after dehydration and condensation, the nano-silica particles aggregate and grow to form secondary particles, which are cross-linked with graphite sheets to form a three-dimensional skeleton structure. The long molecular chain of dihexylenetriamine makes the cross-linking points dispersed, and the pore size increases accordingly, thereby obtaining a low-density aerogel, which can not only play a skeleton role in the asphalt matrix and enhance the stability of the antioxidant, but also isolate the persecution of aging factors such as oxygen and moisture, thereby further enhancing the mechanical properties and anti-aging properties of asphalt; at the same time, the exposed graphene on the pore wall can act as the nuclear site of silicate, one of the components of asphalt filler, to form hydrated crystals, fill the pores and cracks of the mixture, and to a certain extent can hinder the generation of cracks, play a template effect, thereby increasing the strength of the matrix.

[0056] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.

Claims

1. An anti-aging enhanced asphalt mixture, characterized in that: The anti-aging enhanced asphalt mixture is prepared by mixing modified graphite with an asphalt mixture.

2. The aging-resistant enhanced asphalt mixture according to claim 1, characterized in that: The modified graphite is prepared by subjecting flake graphite to ball milling modification treatment.

3. The aging-resistant enhanced asphalt mixture according to claim 1, characterized in that: The asphalt mixture is prepared by mixing asphalt and concrete.

4. A method for preparing an aging-resistant enhanced asphalt mixture, characterized in that: The method comprises the following preparation steps: (1) flake graphite and 30 wt% hydrogen peroxide are mixed uniformly, concentrated nitric acid is added, and the mixture is placed in an ice water bath, stirred at 200-400 rpm until the reaction is smooth, reacted at 18-25° C. for 40-90 min, washed with a 30 wt% nitric acid aqueous solution for 3-6 times, and then a 70 wt% acetic acid aqueous solution is added, stirred at 100-200 rpm for 10-40 min, filtered, and the solid is taken, washed with deionized water for 3-6 times, then mixed with sodium lignin sulfonate, epoxy triacetate, and deionized water, stirred at 8000-15000 rpm for 20-50 min, and then ball milled, centrifuged, and a modified graphite dispersion is obtained; (2) Mixing tetraethyl orthosilicate and anhydrous ethanol, stirring at 60-120 rpm for 5-20 min, adjusting the solution pH to 2.5-3.5 with dilute hydrochloric acid, continuing stirring for 10-30 min, adding modified graphite dispersion and dihexylenetriamine, adjusting the solution pH to 7-8 with ammonia water, standing at 40-80° C. for 4-8 h, then immersing in anhydrous ethanol, aging for 48 h, taking out, and then immersing in n-hexane, standing for 48 h, taking out, and drying at 60-130° C. for 2-6 h to obtain a low-density aerogel; (3) Cut the low-density aerogel into blocks, and then mix it with No. 90 base asphalt, tris[2,4-di-tert-butylphenyl] phosphite, and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacic acid ester, heat it to 140-180°C, stir it at 60-200rpm for 4-8h, add modified graphite dispersion, silicate cement, limestone with a specification of 10-20mm, limestone with a specification of 1-10mm, fly ash, sulfur, terpene resin, and acetone, stir it at 20-30Hz and 100-200rpm for 30-50min, and obtain an aging-resistant reinforced asphalt mixture.

5. The method for preparing an aging-resistant enhanced asphalt mixture according to claim 4, characterized in that: The process parameters of the ball milling in step (1) are as follows: the ball milling medium is agate balls, the ball-to-material ratio is 10:1, the rotation speed is 1350 rpm, and the time is 1.5 to 3 hours.

6. The method for preparing an aging-resistant enhanced asphalt mixture according to claim 4, characterized in that: The centrifugal speed in step (1) is 500-900 rpm and the time is 30-70 min.

7. The method for preparing an aging-resistant enhanced asphalt mixture according to claim 4, characterized in that: The mass ratio of the flake graphite, 30wt% hydrogen peroxide, concentrated nitric acid, 70wt% acetic acid aqueous solution, sodium lignin sulfonate, epoxy triacetate and deionized water in step (1) is 1-7:1:10-16:3-10:3-10:20-50:

500.

8. The method for preparing an aging-resistant enhanced asphalt mixture according to claim 4, characterized in that: The mass ratio of the tetraethyl orthosilicate, anhydrous ethanol, modified graphite dispersion and dihexylenetriamine in step (2) is 1-6:2-10:10-30:0.1-0.

5.

9. The method for preparing an aging-resistant enhanced asphalt mixture according to claim 4, characterized in that: The size of the block in step (3) is 0.1 cm×0.1 cm×0.5 cm.

10. The method for preparing an aging-resistant enhanced asphalt mixture according to claim 4, characterized in that: The mass ratio of the low-density aerogel, No. 90 matrix asphalt, tris[2,4-di-tert-butylphenyl]phosphite, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacic acid ester, modified graphite dispersion, silicate cement, limestone with a specification of 10 to 20 mm, limestone with a specification of 1 to 10 mm, fly ash, sulfur, terpene resin and acetone in step (3) is 1 to 5:20 to 50:3:3:1 to 10:10:25 to 70:14:5:1 to 10:2:10.

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