A fiber-reinforced asphalt mixture and its preparation and use

Abstract

The application discloses a kind of mixed fiber recycled asphalt mixture and preparation and application thereof, belong to bituminous material technical field, the mixed fiber recycled asphalt mixture, by mass parts, including new aggregate 50~95 parts, asphalt mixture recycling material 5~60 parts, new asphalt 2~5 parts, fiber 0.1~0.5 parts, regenerant 0.01~0.5 parts and penetration type regenerant 0.005~0.05 parts;The penetration type regenerant is the quaternary ammonium salt structure that amino-containing pyridine is obtained by reaction with halogenated alkane through door Shu Er Jintu reaction;Add regenerant and penetration type regenerant and the aging asphalt in asphalt mixture recycling material, make asphaltene in aging asphalt depolymerization, so that aging asphalt is regenerated;Add fiber to enhance the high-temperature performance, water stability and fatigue performance of recycled asphalt mixture.

Description

Technical Field

[0001] This invention belongs to the field of asphalt material technology, specifically relating to a fiber-reinforced recycled asphalt mixture and its preparation and application. Background Technology

[0002] my country's total expressway mileage is nearly 180,000 km, of which over 95% is asphalt pavement. Asphalt materials are affected by various factors during their service life, including ultraviolet radiation, high-temperature oxidation, water erosion, and load-bearing effects. These factors cause changes in the chemical composition of asphalt, leading to a gradual decline in its performance over time and ultimately affecting the service life of asphalt pavements. Therefore, asphalt pavements need to be repaired and maintained. In the process of highway maintenance, the disposal of waste asphalt mixtures generated from milling old pavements has always been a challenge. Traditional waste disposal methods involve dumping them in landfills, which not only occupies a large amount of land resources but also pollutes the surrounding environment. Furthermore, waste asphalt mixtures contain many renewable resources, such as stone and asphalt. Maximizing resource utilization and reducing environmental pollution has become a research hotspot in the field of highway construction.

[0003] In recent years, scholars both domestically and internationally have conducted extensive research on these issues, proposing solutions for the recycling and reuse of waste asphalt mixtures to more effectively utilize and process them and reduce land resource occupation. Studies have shown that the cost of recycled waste asphalt can be reduced by about one-quarter. Hot-recycled mixtures prepared using thermal recycling technology exhibit good high-temperature stability and fatigue resistance, and can be used in pavement structures at higher layers, truly realizing the recycling of aged asphalt in asphalt mixtures rather than simply "reusing" it. However, increasing the content of recycled asphalt in asphalt mixtures leads to a decrease in the water stability and fatigue performance of hot-recycled asphalt mixtures. To improve the road performance of recycled asphalt mixtures, experts at home and abroad have proposed various solutions, such as adding fibers to the recycled asphalt mixture and preparing recycled asphalt with various high-efficiency modifiers. A key aspect of asphalt pavement recycling technology is the use of asphalt recycling agents; selecting high-efficiency recycling agents is a prerequisite for achieving high-value utilization of recycled asphalt mixtures. Good penetration and diffusion characteristics are a basic performance requirement for asphalt recycling agents and a prerequisite for thorough mixing of new and old asphalt. Currently, the asphalt recycling agents commonly used in engineering are all non-renewable fossil resources. They are not only expensive and harmful to the human body, but also cannot simultaneously improve the penetration, diffusion and depolymerization effects of asphalt in recycled asphalt mixtures. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention provides a fiber-blended recycled asphalt mixture and its preparation method. A regenerator and a penetrating regenerator are added to react with the aged asphalt in the recycled asphalt mixture, causing the asphaltene in the aged asphalt to depolymerize, thereby regenerating the aged asphalt. Fiber is added to enhance the water stability and fatigue performance of the recycled asphalt mixture.

[0005] The technical solution for achieving the objective of this invention is as follows:

[0006] A fiber-reinforced recycled asphalt mixture, comprising, by weight, 50-95 parts new aggregate, 5-60 parts recycled asphalt mixture, 2-5 parts new asphalt, 0.1-0.5 parts fiber, 0.01-0.5 parts rejuvenator, and 0.005-0.05 parts penetrating rejuvenator; wherein the penetrating rejuvenator is a quaternary ammonium salt structure obtained by reacting amino-containing pyridine with haloalkanes via the Mensutkin reaction.

[0007] Preferably, the mass fraction of asphalt content in the recycled asphalt mixture is 2~10 wt%.

[0008] Preferably, the fiber is one or a combination of lignin fiber, polyester fiber, basalt fiber and glass fiber; the new aggregate includes coarse aggregate, fine aggregate and mineral powder.

[0009] Preferably, the regenerant is at least one of a petroleum-based regenerant and a bio-oil-based regenerant.

[0010] Specifically, the regenerant is one or more of the following: squalane, 1,3-dimethylnaphthalene, oleic acid, soybean oil, castor oil, rapeseed oil, 2-methoxyphenol, glycerol, hexadecamide, palmitic acid, stearic acid, 4,5-dihydro-5-methyl-2(3H)-furanone, triethylene glycol monoethyl ether, and methyl palmitate.

[0011] Preferably, the permeation-type regenerator has the following molecular structure:

[0012] Formula I; in Formula I, R1 and R2 are at least one straight-chain and branched alkyl group with a total number of C atoms of 2 to 30; R3 is at least one aliphatic hydrocarbon with a total number of C atoms of 10 to 30; R5 and R6 are at least one of H, CH3, and CH2CH3.

[0013] More preferably, the permeation-type regenerant has at least one molecular structure of formula II, formula III, or formula IV:

[0014] Formula II;

[0015] Formula III;

[0016] Formula IV;

[0017] The preparation method of the molecular structure of Formula II is as follows:

[0018] S1.N-(tert-Butoxycarbonyl)ethanolamine is condensed with oleic acid using the condensing agents dicyclohexylcarbodiimide and 4-dimethylaminopyridine, and then trifluoroacetic acid is added to remove the protecting group to obtain oleic acid ethanolamine ester;

[0019] S2. The obtained oleic acid ethanolamine ester and bromoacetyl bromide undergo an acylation reaction under the catalysis of an acid-binding agent to obtain brominated oleic acid;

[0020] S3. The obtained brominated oleic acid reacted with 4-dimethylaminopyridine via the Menshutkin reaction to obtain the molecular structure of formula II;

[0021] The preparation method of the III molecular structure is to replace 4-dimethylaminopyridine in step S3 of the preparation method of the II molecular structure with 4-methylaminopyridine.

[0022] The method for preparing the IV molecular structure is to replace 4-dimethylaminopyridine in step S3 of the method for preparing the II molecular structure with 4-aminopyridine.

[0023] Specifically, the preparation method of the molecular structure of Formula II is as follows:

[0024] S1. Under an inert gas atmosphere and ice bath conditions, 1–1.2 eq of oleic acid and 1 eq of N-(tert-butyloxycarbonyl)ethanolamine were dissolved in 15–20 eq of dichloromethane. 1.2–2.0 eq of dicyclohexylcarbodiimide and 0.1–0.3 eq of 4-dimethylaminopyridine were added, and the mixture was brought back to room temperature and stirred for 12–24 h. The reaction solution was filtered through a sintered glass funnel to remove the precipitate. The filtrate was washed at least twice each with 1–2 mol / L dilute hydrochloric acid, saturated NaHCO3 solution, and water. The organic phase was dried with anhydrous sodium sulfate, filtered, and an equal volume of trifluoroacetic acid was added to the obtained organic phase. After stirring at 25–35 °C for 1–2 h, a certain amount of dichloromethane solution was added, and saturated NaHCO3 solution was added to adjust the pH to neutral or weakly alkaline. Extraction was performed, and the organic phase was collected. The organic phase was washed with brine, dried with anhydrous sodium sulfate, and concentrated to obtain oleic acid ethanolamine ester.

[0025] S2. Under an inert gas atmosphere and ice bath conditions, 1 eq of oleic acid ethanolamine ester and 1.5-3.0 eq of triethylamine obtained in step S1 are dissolved in 15-20 eq of anhydrous dichloromethane. 1.2-2.0 eq of bromoacetyl bromide solution dispersed in 10 eq of anhydrous dichloromethane is slowly added dropwise. The mixture is heated to 25-35 °C and stirred for 2-5 h. Excess bromoacetyl bromide is then slowly quenched with ice water. The resulting solution is washed at least twice each with 1-2 mol / L dilute hydrochloric acid, saturated NaHCO3 solution, and saturated sodium chloride. The resulting organic phase is dried over anhydrous sodium sulfate, filtered, concentrated by rotary evaporation, and purified by column chromatography to obtain brominated oleic acid.

[0026] S3. A mixture of 1 eq of 4-dimethylaminopyridine and 1.0-1.5 eq of bromooleic acid obtained in step S3 dispersed in 10-15 eq of acetonitrile was stirred at 50-90 °C for 12-24 h. After the reaction mixture was cooled, diethyl ether was added to precipitate the product. The product was filtered, and the solid was washed with diethyl ether at least twice and then dried under vacuum to obtain the molecular structure of formula II.

[0027] This invention also discloses a method for preparing fiber-reinforced recycled asphalt mixture, comprising the following steps:

[0028] 1) Analysis of the composition of recycled asphalt mixture: The recycled asphalt mixture was extracted, and the moisture content and asphalt content were measured. The old aggregate after centrifugal extraction was screened, and the screening and distribution results were analyzed.

[0029] 2) Pretreatment and preheating: Heat the recycled asphalt mixture to 130~150 ℃, add the penetrating recycling agent to the recycling agent and heat to 100~110 ℃, heat the new aggregate to 160-180 ℃, remove moisture, and according to the old aggregate screening and grading results in step 1), grade and screen the new aggregate according to the design requirements, and heat the new asphalt to 145~165 ℃;

[0030] 3) Mixing: Add the preheated penetrating recycling agent and recycling agent to the asphalt mixture recycled material and mix for 80~100 s. Then add coarse aggregate, fine aggregate and new asphalt and continue mixing for 40~60 s. Then add fiber and mix for 40~60 s. Finally add mineral powder and mix for 80~100 s.

[0031] Another objective of this invention is to protect the application of the aforementioned fiber-reinforced recycled asphalt mixture in asphalt pavement materials.

[0032] Specifically, it includes the following steps:

[0033] The mixed fiber-recycled asphalt mixture is transported in a refrigerated truck, paved by a paver, initially compacted by a double-drum vibratory roller, then compacted again by a rubber-tired roller, and finally compacted with a double-drum vibratory roller, and cured for 24-36 hours.

[0034] Beneficial effects

[0035] This invention provides a fiber-reinforced recycled asphalt mixture and its preparation method. A rejuvenating agent and a penetrating rejuvenating agent are added to react with aged asphalt in the recycled asphalt mixture, causing the asphaltenes in the aged asphalt to depolymerize, thereby regenerating the aged asphalt and enhancing the road performance of the recycled asphalt mixture. The rejuvenating agent mainly provides lubrication. The penetrating rejuvenating agent has long-chain alkyl, amide, quaternary ammonium salt, amino, and pyridine ring structures in its molecular structure, which play a depolymerization role. The NH bond in the amide structure can form hydrogen bonds with the carbonyl and ether bonds in the asphalt, and the carbonyl group can form hydrogen bonds with the hydroxyl and carboxyl groups, reducing the hydrogen bonding between asphalt. The quaternary ammonium salt structure can attract the anions in the asphalt through electrostatic attraction, playing an anchoring role. Before adding the recycled asphalt mixture, the penetrating rejuvenating agent can prevent itself from being added by its own electrostatic repulsion. The addition of alkyl groups enhances the dispersibility of asphalt and provides positive charge and electrostatic repulsion to asphalt, thus inhibiting aggregation. The amino structure can neutralize acidic groups in asphalt components, such as carboxyl groups; if it is a primary amine, it can also react with carbonyl structures, reducing the interaction between polar molecules of different asphaltenes. The quaternized pyridine structure used is an electron-deficient aromatic ring, acting as a guide. It can form charge-transfer complexes with electron-rich asphaltenes through electron donor-acceptor charge transfer, facilitating the deep diffusion, penetration, and anchoring of the penetrating regenerator in the asphaltene. Simultaneously, it affects the aggregation state of asphalt molecules, promoting depolymerization. Long-chain alkyl groups, similar in structure to the light components in asphalt, improve compatibility and dispersibility in aged asphalt and possess a certain spatial volume. When inserted between layered asphalt molecules, they can hinder the π-π stacking between aromatic rings, reducing the stability of asphaltene aggregates. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the synthesis route and structure of the penetrating regenerator 1 of the present invention;

[0037] Figure 2 This is the 1H NMR spectrum of the permeation-type regenerator 1 of the present invention. Detailed Implementation

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] Unless otherwise specified, the experimental methods used in the embodiments are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0040] The raw materials and equipment used in the embodiments and comparative examples are described below:

[0041] New aggregate: It is composed of coarse aggregate (diabase), fine aggregate (river sand) and mineral powder (purchased from Huzhou Lanyun Ore Powder Co., Ltd.) screened and graded; the physical and mechanical properties of coarse and fine aggregates meet the relevant requirements of JTG F40-2004 specification;

[0042] Recycled asphalt mixture: The aged asphalt mixture after milling of the top layer from the Guangming Expressway overhaul project is used, and is divided into two grades: 0~9.5 mm and 9.5~19 mm.

[0043] New asphalt: No. 70 heavy-grade asphalt;

[0044] Fiber: Polyester fiber, white filaments, tensile strength >540 MPa, length 25.0 mm;

[0045] Regenerator: Oleic acid, purchased from Shanghai Jizhi Biochemical Technology;

[0046] N-(tert-Butoxycarbonyl)ethanolamine: purchased from Shanghai Maclean;

[0047] Dicyclohexylcarbodiimide: purchased from Shanghai Maclean;

[0048] 4-Dimethylaminopyridine: purchased from Shanghai Maclean;

[0049] Bromoacetyl bromide: purchased from Shanghai Maclean;

[0050] 5-Methylaminopyridine: purchased from Shanghai Maclean;

[0051] 4-Aminopyridine: purchased from Shanghai Maclean;

[0052] Penetrating regenerator 1

[0053] S1. Under an inert gas atmosphere and ice bath conditions, 1.2 eq of oleic acid and 1 eq of N-(tert-butyloxycarbonyl)ethanolamine were dissolved in 20 eq of dichloromethane. 2.0 eq of dicyclohexylcarbodiimide and 0.3 eq of 4-dimethylaminopyridine were added, and the mixture was brought back to room temperature and stirred for 24 h. The reaction solution was filtered through a sintered glass funnel to remove the precipitate. The filtrate was washed twice each with 1 mol / L dilute hydrochloric acid, saturated NaHCO3 solution, and water. The organic phase was dried with anhydrous sodium sulfate, filtered, and an equal volume of trifluoroacetic acid was added to the obtained organic phase. After stirring at 30 °C for 1-2 h, a certain amount of dichloromethane solution was added, and saturated NaHCO3 solution was added to adjust the pH to weakly alkaline. Extraction was performed, and the organic phase was collected. The organic phase was washed with brine, dried with anhydrous sodium sulfate, and concentrated to obtain oleic acid ethanolamine ester.

[0054] S2. Under an inert gas atmosphere and ice bath conditions, 1 eq of oleic acid ethanolamine ester and 2.0 eq of triethylamine obtained in step S1 were dissolved in 20 eq of anhydrous dichloromethane. 1.8 eq of bromoacetyl bromide solution dispersed in 10 eq of anhydrous dichloromethane was slowly added dropwise. After stirring at 30 °C for 3 h, excess bromoacetyl bromide was slowly quenched with ice water. The resulting solution was washed twice each with 1 mol / L dilute hydrochloric acid, saturated NaHCO3 solution, and saturated sodium chloride solution. The resulting organic phase was dried over anhydrous sodium sulfate, filtered, concentrated by rotary evaporation, and purified by column chromatography to obtain brominated oleic acid.

[0055] S3. A mixture of 1 eq of 4-dimethylaminopyridine and 1.2 eq of bromooleic acid obtained in step S3 dispersed in 15 eq of acetonitrile was stirred at 80 °C for 15 h. After the reaction mixture was cooled, diethyl ether was added to precipitate the product. The product was filtered, washed twice with diethyl ether, and dried under vacuum to obtain the penetrating regenerant 1.

[0056] Penetrating regenerator 2

[0057] Compared with the preparation method of the penetrating regenerator 1, the difference is that 4-dimethylaminopyridine in step S3 is replaced with 4-methylaminopyridine.

[0058] Penetrating regenerator 3

[0059] Compared with the preparation method of the penetrating regenerator 2, the difference is that 4-dimethylaminopyridine in step S3 is replaced with 4-aminopyridine.

[0060] Penetrating regenerator 4

[0061] The difference between this method and the preparation method of the penetrating regenerator 2 is that only step S1 is performed.

[0062] Penetrating regenerator 5

[0063] 4-Dimethylaminopyridine was selected.

[0064] The following are the test methods for performance parameters involved in this invention:

[0065] Asphalt content determination:

[0066] (1) Weigh a certain mass of recycled asphalt mixture, denoted as m1, and soak it in trichloroethylene solvent for more than 12 hours;

[0067] (2) Pour the soaked asphalt mixture recycled material and solution into the asphalt mixture extractor and run it at a rate of 4000 r / min for 3~5 min until the aggregate turns white. Collect the extract after centrifugation and filter and weigh the aggregate mass as m2.

[0068] (3) The extract is divided into four centrifuge tubes and centrifuged in a mineral powder centrifuge at a rate of 3000±500 r / min for 30~40 min to allow the mineral powder to settle fully. After slowly pouring out the upper layer of asphalt and trichloroethylene mixed solution, the mineral powder in the centrifuge tube is placed in an oven to dry fully and weighed as m3.

[0069] (4) Pour the mixed solution of asphalt and trichloroethylene into a pear-shaped flask and perform vacuum distillation using a rotary evaporator. First, set the oil bath temperature to 60 °C and the vacuum degree to 180 mbar, and evaporate until no more solvent precipitates in the solvent receiving flask. Then, raise the temperature to 135 °C and lower the vacuum degree to 60 mbar, and evaporate for 15-30 minutes. Finally, pour out the remaining asphalt from the flask.

[0070] Asphalt content = ;

[0071] Penetration: After extraction of asphalt, aged asphalt and recycled asphalt were tested separately according to GB / T 4509-2010 "Asphalt Penetration Test Method" (25 ℃, 100 g, 5 s); the preparation method of recycled asphalt was as follows: aged asphalt was heated to 140 ℃, penetrating recycling agent was added to the recycling agent and heated to 105 ℃, and the preheated penetrating recycling agent and recycling agent were added to the asphalt mixture recycled material and stirred for 80 s.

[0072] Marshall test stability: Specimens were prepared and tested according to "JTJ 052-2000 Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering";

[0073] High temperature stability: Specimens were prepared by wheel rolling molding according to T0703 of "JTPE20-2011 Highway Engineering Asphalt and Asphalt Mixture Test Procedures". The specimen size was 300 mm long × 300 mm wide × 50 mm thick. The specific operation steps were carried out according to the requirements of specification T0719. The test temperature was 60℃ and the wheel pressure was 0.7 MPa.

[0074] Water stability: Specimens were prepared according to the "JTPE20-2011 Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering"; and evaluated by immersion Marshall test and freeze-thaw splitting test.

[0075] A method for preparing fiber-reinforced recycled asphalt mixture includes the following steps:

[0076] 1) Analysis of the composition of recycled asphalt mixture: Recycled asphalt mixtures with different particle size ranges were extracted, and the moisture content and asphalt content were measured. The old aggregates after centrifugation were screened, and the screening and distribution results were analyzed.

[0077] 2) Pretreatment and preheating: Heat the recycled asphalt mixture to 140 ℃, add the penetrating recycling agent to the recycling agent and heat to 105 ℃, heat the new aggregate and mineral powder to 170 ℃ to remove moisture, and according to the old aggregate grading and distribution results in step 1), grade and sieve the new aggregate and mineral powder according to the design requirements of AC-20 in Table 3, and heat the new asphalt to 150 ℃;

[0078] 3) Mixing: Add the preheated penetrating recycler and recycler to the asphalt mixture recycled material and mix for 90 seconds. Then add new aggregate and new asphalt and continue mixing for 60 seconds. Then add fiber and mix for 40 seconds. Finally, add mineral powder and mix for 90 seconds.

[0079] Table 1. Asphalt content, penetration, and sieve analysis results of recycled asphalt mixtures.

[0080]

[0081] Table 2. Determination of the recycling performance of asphalt extracted from recycled materials

[0082]

[0083] As shown in Table 2, the regenerator and penetrating regenerator prepared in this invention have a good depolymerization effect on the asphalt in the recycled asphalt mixture. Data from Preparation Examples 1-3 show that the penetration of the recycled asphalt gradually increases with the increase of the regenerator and penetrating regenerator components, indicating that the regeneration effect gradually improves. Data from Preparation Examples 2, 4, and 5 show that, within a certain range, the higher the proportion of the penetrating regenerator component, the greater the penetration of the recycled asphalt. Data from proportions 2, 6, and 7 show that the penetrating regenerator 3 prepared using 4-aminopyridine has the best regeneration effect. This is because the amino group, in addition to neutralizing the acidic groups in the asphalt components, also exhibits hydrogen bonding interactions with the asphalt matrix structure and reactions with aldehyde groups. Preparation Examples 8 and 10 show that Preparation Example 8 is more effective than Preparation Example 10. This is because Preparation Example 8 introduces an amino structure compared to Preparation Example 10, providing hydrogen bonding interactions with the asphalt matrix structure. As can be seen from the data in Preparation Example 9, the regeneration effect of directly mixing 4-dimethylaminopyridine and oleic acid is not as good as that of chemical modification.

[0084] Based on the data summary in Table 2, the recommended usage of 12%wt recycled asphalt and penetrating recycled asphalt mixtures was determined by the quality of the recycled asphalt.

[0085] Table 3. Upper and lower limits and median of AC-20 range

[0086]

[0087] The application of a fiber-reinforced recycled asphalt mixture in asphalt pavement materials includes the following steps:

[0088] The mixed fiber-recycled asphalt mixture was transported in a refrigerated truck, paved with a paver, initially compacted with a double-drum vibratory roller, then compacted again with a rubber-tired roller, and finally compacted with a double-drum vibratory roller, and cured for 36 hours.

[0089] Table 4. Formulations of fiber-reinforced recycled asphalt mixtures in Examples 1-5 (unit: kg)

[0090]

[0091] Table 5. Formulations of fiber-reinforced recycled asphalt mixtures for Comparative Examples 1-5 (unit / kg)

[0092]

[0093] Table 6 Performance data of fiber-reinforced recycled asphalt in Examples 1-5

[0094]

[0095] As shown in Table 6, the fiber-reinforced recycled asphalt prepared in this invention exhibits excellent performance. Data from Examples 1-3 and Comparative Example 5 indicate that the Marshall test stability of Examples 1-3 is slightly lower than that of Comparative Example 5. With increasing recycled material content in the asphalt mixture, the Marshall test stability and high-temperature stability gradually increase. When the recycled material content is low, the aged asphalt within it fails to effectively fuse with the new asphalt. As the proportion increases, the aged asphalt gradually softens during high-temperature mixing and interacts with the new asphalt, forming a more uniform cementitious system, and the shear strength of the mixture gradually recovers. Data from Examples 1-3 show that with increasing recycled material content in the asphalt mixture, water stability gradually decreases. Examples 1-2 are superior to Comparative Example 5, indicating that the addition of the recycling agent reduces the sensitivity of the mixture to water damage to a certain extent, which is beneficial to water stability. Data from Examples 2, 4, and 5 show that the high-temperature stability of the asphalt with added penetrating rejuvenators 1-3 is in the order of penetrating rejuvenator 1 > penetrating rejuvenator 2 > penetrating rejuvenator 3. However, other properties are in the order of penetrating rejuvenator 3 > penetrating rejuvenator 2 > penetrating rejuvenator 1. The difference in high-temperature stability is due to the difference in stability among primary, secondary, and tertiary amines. Primary amines are more easily oxidized at high temperatures. However, as shown in Table 2, primary amines have a better regeneration effect on aged asphalt, and therefore other properties are superior. Comparative Examples 1-2 show that simple physical blending or the absence of pyridine groups results in poor performance of fiber-regenerated asphalt. Comparative Examples 3-4 show that fiber-regenerated asphalt without the addition of the penetrating rejuvenator of this invention or without the addition of any rejuvenator has poor performance.

[0096] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A fiber-reinforced recycled asphalt mixture, characterized in that, The fiber-blended recycled asphalt mixture, by weight, comprises 50-95 parts of new aggregate, 5-60 parts of recycled asphalt mixture, 2-5 parts of new asphalt, 0.1-0.5 parts of fiber, 0.01-0.5 parts of rejuvenator, and 0.005-0.05 parts of penetrating rejuvenator; the penetrating rejuvenator is a quaternary ammonium salt structure obtained by reacting amino-containing pyridine with haloalkanes via the Mensutkin reaction; the penetrating rejuvenator has the following molecular structure: Formula I; in Formula I, R1 and R2 are at least one straight-chain and branched alkyl group with a total number of C atoms of 2 to 30; R3 is at least one aliphatic hydrocarbon with a total number of C atoms of 10 to 30; R5 and R6 are at least one of H, CH3, and CH2CH3.

2. The fiber-reinforced recycled asphalt mixture as described in claim 1, characterized in that, The mass fraction of asphalt content in the recycled asphalt mixture is 2~10 wt%.

3. The fiber-reinforced recycled asphalt mixture as described in claim 1, characterized in that, The fiber is one or a combination of lignin fiber, polyester fiber, basalt fiber and glass fiber; the new aggregate includes coarse aggregate, fine aggregate and mineral powder.

4. The fiber-reinforced recycled asphalt mixture as described in claim 1, characterized in that, The regenerant is at least one of a petroleum-based regenerant and a bio-oil-based regenerant.

5. The fiber-reinforced recycled asphalt mixture as described in claim 1, characterized in that, The regenerant is one or more of squalane, 1,3-dimethylnaphthalene, oleic acid, soybean oil, castor oil, rapeseed oil, 2-methoxyphenol, glycerol, hexadecamide, palmitic acid, stearic acid, 4,5-dihydro-5-methyl-2(3H)-furanone, triethylene glycol monoethyl ether, and methyl palmitate.

6. The fiber-reinforced recycled asphalt mixture as described in claim 1, characterized in that, The permeation-type regenerant has at least one molecular structure of formula II, formula III, or formula IV: Formula II; Formula III; Formula IV; The preparation method of the molecular structure of Formula II is as follows: S1.N-(tert-Butoxycarbonyl)ethanolamine is condensed with oleic acid using the condensing agents dicyclohexylcarbodiimide and 4-dimethylaminopyridine, and then trifluoroacetic acid is added to remove the protecting group to obtain oleic acid ethanolamine ester; S2. The obtained oleic acid ethanolamine ester and bromoacetyl bromide undergo an acylation reaction under the catalysis of an acid-binding agent to obtain brominated oleic acid; S3. The obtained brominated oleic acid reacted with 4-dimethylaminopyridine via the Menshutkin reaction to obtain the molecular structure of formula II; The preparation method of the III molecular structure is to replace 4-dimethylaminopyridine in step S3 of the preparation method of the II molecular structure with 4-methylaminopyridine. The method for preparing the IV molecular structure is to replace 4-dimethylaminopyridine in step S3 of the method for preparing the II molecular structure with 4-aminopyridine.

7. The method for preparing a fiber-reinforced recycled asphalt mixture as described in claim 3, characterized in that, Includes the following steps: 1) Analysis of the composition of recycled asphalt mixture: The recycled asphalt mixture was extracted, and the moisture content and asphalt content were measured. The old aggregate after centrifugal extraction was screened, and the screening and distribution results were analyzed. 2) Pretreatment and preheating: Heat the recycled asphalt mixture to 130~150 ℃, add the penetrating recycling agent to the recycling agent and heat to 100~110 ℃, heat the new aggregate to 160-180 ℃, remove moisture, and according to the old aggregate screening and grading results in step 1), grade and screen the new aggregate according to the design requirements, and heat the new asphalt to 145~165 ℃; 3) Mixing: Add the preheated penetrating recycling agent and recycling agent to the asphalt mixture recycled material and stir for 80~100s. Then add coarse aggregate, fine aggregate and new asphalt and continue stirring for 40~60s. Then add fiber and mix for 40~60s. Finally add mineral powder and stir for 80~100s.

8. The application of a fiber-reinforced recycled asphalt mixture as described in any one of claims 1 to 7 in asphalt pavement materials.

9. The application of the fiber-reinforced recycled asphalt mixture as described in claim 8 in asphalt pavement materials, characterized in that, Includes the following steps: The mixed fiber-recycled asphalt mixture is transported in a refrigerated truck, paved by a paver, initially compacted by a double-drum vibratory roller, then compacted again by a rubber-tired roller, and finally compacted with a double-drum vibratory roller, and cured for 24-36 hours.

Images