Modified spun ceramic fiber asphalt mixture, preparation method and application thereof

Abstract

The application discloses a modified spinning type ceramic fiber asphalt mixture, a preparation method and application thereof, and belongs to the technical field of asphalt modification. The modified spinning type ceramic fiber asphalt is prepared by the following method: under high-temperature conditions, aggregate and modified spinning type ceramic fiber are mixed and stirred; then, base asphalt is added and stirred; finally, modified mineral powder is added and stirred to obtain the modified spinning type ceramic fiber asphalt mixture. Based on the combined action of the modified spinning type ceramic fiber and the modified mineral powder, the characteristics of the asphalt material are changed in the microstructure, so that the performance of the asphalt mixture is greatly optimized, and the high-temperature stability, low-temperature stability and water stability are significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of asphalt modification technology, specifically relating to a modified spun ceramic fiber asphalt mixture, its preparation method and application. Background Technology

[0002] With the gradual increase in traffic volume, new requirements are being placed on roads. However, due to various extreme environments and loads, such as high temperature, low temperature, and heavy rainfall, asphalt pavements may develop rutting, cracking, and other adverse conditions, damaging their structural integrity and affecting their service life. Rutting in asphalt pavements is a type of shear failure, and its shear strength depends on the cohesion of the asphalt mastic or mastic and the internal friction of the aggregate. Adding fibers to asphalt mixtures is an effective way to improve pavement durability and extend its service life, meeting the service requirements of pavement materials under high traffic volume and complex environmental conditions. Spinned ceramic fibers are commonly used as fireproofing materials, possessing advantages such as high modulus, low density, and high heat resistance. They can withstand long-term exposure to acidic and alkaline environments without decomposition or deterioration, meeting the basic requirements for pavement materials. Simultaneously, due to the adsorption effect of fibers and their role as activators, the viscosity and cohesion of asphalt increase. Furthermore, the reinforcing effect of the interwoven fibers improves various properties of the asphalt mixture. Ceramic fiber-modified asphalt exhibits lower temperature sensitivity and better thermal insulation properties, altering the thermodynamic properties of asphalt and thus improving its high-temperature resistance. However, ceramic fibers, as reinforcements, have smooth surfaces, are chemically inert, and have low surface energy, resulting in low interaction energy with the asphalt matrix and poor adhesion, which reduces the overall mechanical properties of asphalt-based materials. Therefore, surface modification of ceramic fibers to improve their compatibility and bonding strength with the asphalt matrix has broad application value. Summary of the Invention

[0003] This invention provides a method for preparing modified spun ceramic fiber asphalt mixture, comprising the following steps:

[0004] Under high temperature conditions, aggregates are mixed with modified spun ceramic fibers and stirred; then base asphalt is added and stirred; finally, modified mineral powder is added and stirred to obtain modified spun ceramic fiber asphalt mixture.

[0005] In the above-mentioned preparation method of modified spun ceramic fiber asphalt mixture, the raw materials are selected from the following parts by weight: 7400-7900 parts of aggregate, 400-420 parts of base asphalt, 40-60 parts of modified spun ceramic fiber, and 300-350 parts of modified mineral powder.

[0006] In the above-mentioned method for preparing modified spun ceramic fiber asphalt mixture, the aggregate is selected from one of basalt, granite, diabase, shale, limestone, and dolomite; the particle size distribution of the aggregate is as follows: 10-15mm 2000-2100 parts, 5-10mm 2300-2500 parts; 0-5mm 3100-3300 parts.

[0007] In the above-mentioned method for preparing modified spun ceramic fiber asphalt mixture, the base asphalt is selected from 70# petroleum asphalt.

[0008] In the above-mentioned method for preparing modified spun ceramic fiber asphalt mixture, the modified spun ceramic fiber is prepared by the following method:

[0009] The spun ceramic fibers are subjected to plasma treatment; the surface modifier is dissolved in an organic solvent, and then the pH is adjusted to weakly alkaline using an alkaline solution to obtain a surface modifier solution; amine polymers or silane coupling agents are added to the surface modifier solution, and then the spun ceramic fibers are added and immersed in the reaction; after the reaction is completed, the spun ceramic fibers are taken out, rinsed, and dried to obtain modified spun ceramic fibers.

[0010] In the above-mentioned method for preparing modified spun ceramic fibers, the mass fractions of each component are as follows:

[0011] The mixture contains 50-60 parts of spun ceramic fiber, 0.4-1 part of surface modifier, 150-200 parts of organic solvent, and 0.1-0.4 parts of amine polymer or silane coupling agent.

[0012] In the above-mentioned method for preparing modified spun ceramic fibers, the spun ceramic fibers are selected from at least one of silicon carbide, aluminum silicate, alumina, and zirconium oxide fibers, and the fiber length is 3-5 mm.

[0013] In the above-mentioned method for preparing modified spun ceramic fibers, the surface modifier is selected from one or more of the following: theaflavin-3-gallate, isoocanine, salvianolic acid B, cyanidin chloride, 4-methylcatechol, chlorogenic acid, gallic acid, catechin gallate, p-tert-butylcatechol, dopamine, 5,6-dihydroxyindole, and 3,4-dihydroxyphenylacetic acid.

[0014] In the above-mentioned method for preparing modified spun ceramic fibers, the organic solvent is selected from at least one of isopropanol, acetonitrile, tris(hydroxymethyl)aminomethane, tetrahydrofuran, dimethylacetamide, ethyl acetate, methanol, dimethylformamide, chloroform, acetone, and dimethyl sulfoxide.

[0015] In the above-mentioned method for preparing modified spun ceramic fibers, the amine compound is selected from tetraethylenepentamine, ethylenediamine, octadecylamine, 2,6-diphenylpyridine, aniline, N-propyl-1,3-diaminopropane, N-isopropyl-1,3-diaminopropane, N-cyclohexyl-1,3-diaminopropane, 3-(2-aminoethyl)aminopropylamine, bis(3-aminopropyl)amine, methylbis(3-aminopropyl)amine, N,N-dimethyldipropylenetriamine, N,N'-bis(3-aminopropyl)-1,3-propanediamine, and ethylenediamine. At least one of the following: 1,3-propanediamine, 1,4-butanediamine, lysine, cystamine, xylenediamine and tris(2-aminoethyl)amine, polyetherimide, N-methyl-1,3-diaminopropane, N-methylpyrrole, 2-(3-aminopropylamino)ethanol, diethylamine, 2-[(4-aminophenyl)amino]benzoic acid, polyethyleneimine, piperidine, polypropylene glycol etheramine, N-(3-aminopropyl)-1,4-diaminobutane, polyethylene glycol etheramine, triethanolamine, 1,2-bis(3-aminopropylamino)ethane, and pyridine.

[0016] In the above-mentioned method for preparing modified spun ceramic fibers, the silane coupling agent is selected from one or more of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, γ-mercaptopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, vinyltriethoxysilane, methyltrimethoxysilane, tetraethoxysilane, vinyltrimethoxysilane, methylvinyldimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, methacryloyloxypropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-cyanopropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and γ-ureidopropyltrimethoxysilane.

[0017] In the above-mentioned method for preparing modified spun ceramic fibers, the alkaline solution is selected from one of sodium hydroxide, potassium hydroxide, ammonia, and ethylenediamine, and the concentration is 0.1 mol / L.

[0018] In the above-mentioned method for preparing modified spun ceramic fibers, the pH of the surface modifier solution is 8-9.

[0019] In the above-mentioned method for preparing modified spun ceramic fibers, the plasma treatment conditions are selected from: plasma processor power of 60-80W, gas flow rate of 10mL-2L / min, gas pressure of 14-17Pa, time of 4-7min, and the gas is selected from argon or helium.

[0020] In the above-mentioned method for preparing modified spun ceramic fibers, the conditions for the soaking reaction are: soaking at room temperature, ultrasonication for 30-50 minutes, and then allowing the reaction to proceed statically for 4-6 hours.

[0021] In the above-mentioned method for preparing modified spun ceramic fiber asphalt mixture, the modified mineral powder can be prepared by the following two methods:

[0022] (1) When using titanate coupling agents for modification, the method is as follows:

[0023] Dissolve the titanate coupling agent in ethanol and let it stand; then add the mineral powder and stir; after stirring is finished, dry it to obtain the titanate coupling agent modified mineral powder.

[0024] The mass fractions of each component are as follows: titanate coupling agent 1-2 parts, ethanol 400-700 parts, mineral powder 200-400 parts;

[0025] The titanate coupling agent is selected from at least one of methyl titanate, isopropyl dioleoyl oxytetrate, monoalkoxy fatty acid ester titanate, butyl titanate, isopropyl dioleoyl oxy(dioctyl phosphate oxy) titanate, ethyl titanate, triisostearate titanate isopropyl titanate, bis(dioctyl pyrophosphate) ethylene titanate, tert-butyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, and monoalkoxy unsaturated fatty acid titanate.

[0026] (2) When using silane coupling agents for modification, the method is as follows:

[0027] Mix silane coupling agent, ethanol and water, and let stand; then add mineral powder and stir; after stirring is finished, dry to obtain silane coupling agent modified mineral powder;

[0028] The mass fractions of each component are as follows: 1-2 parts silane coupling agent, 500-700 parts ethanol, 200-400 parts water, and 200-400 parts mineral powder.

[0029] The silane coupling agent is selected from at least one of vinyltris(β-methoxyethoxy)silane, phenyltrimethoxysilane, 3-[2-(2-aminoethylamino)ethylamino]propyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, vinyltris(β-methoxyethoxy)silane, and phenyltriethoxysilane.

[0030] In the above-mentioned method for preparing modified mineral powder, the mineral powder is selected from one of basalt, S75 granulated blast furnace slag powder, fly ash, red mud, S95 granulated blast furnace slag powder, S105 granulated blast furnace slag powder, coal gangue powder, and phosphogypsum, and its particle size is less than 0.075 mm.

[0031] In the above-mentioned method for preparing modified mineral powder, the standing time is 1-3 hours; the stirring time is 20-35 minutes; and the drying temperature is 60-80°C.

[0032] In the above-mentioned method for preparing modified spun ceramic fiber asphalt mixture, the high temperature condition is selected from 160-170℃.

[0033] In the above-mentioned preparation method of modified spun ceramic fiber asphalt mixture, except for the modified spun ceramic fiber, other materials need to be preheated before use. Among them, aggregates and modified mineral powder can be preheated to constant weight at 150-170℃; base asphalt can be preheated to melt at 130-150℃.

[0034] In the above-mentioned method for preparing modified spun ceramic fiber asphalt mixture, the stirring time is selected from 50 to 100 seconds.

[0035] The present invention provides a modified spun ceramic fiber asphalt mixture prepared by the above method.

[0036] This invention provides the application of the above-mentioned modified spun ceramic fiber asphalt mixture in the construction of vehicular road surfaces.

[0037] The beneficial effects of this invention are as follows:

[0038] This invention leverages the combined action of modified fibers and modified mineral powder to alter the microstructure of asphalt materials, thereby significantly optimizing the performance of asphalt mixtures. For example, high-temperature stability, low-temperature stability, and water stability are all substantially improved. The modified fibers effectively reduce fiber agglomeration and low dispersibility, enhancing the compatibility between fibers and asphalt. Furthermore, a two-phase composite material is formed between the fibers and asphalt. When stress is transferred at the fiber-asphalt bonding interface, the fibers confine internal defects and bear internal stress, thus improving the overall performance of the mixture.

[0039] This invention employs a plasma method to pretreat fibers. After introducing non-reactive gases, the argon and helium gases used in this invention are stable and have low discharge voltages, easily forming metastable atoms. On one hand, through the physical action of the aforementioned high-energy particles, contaminants on the fiber surface are bombarded to form volatile contaminants, which are then removed by a vacuum pump, cleaning the fiber surface and preventing surface material reactions. On the other hand, by bombarding the fiber surface with high-energy particles, a certain etching effect can be achieved while cleaning the fiber, improving the fiber surface roughness and effective contact area.

[0040] This invention employs a co-deposition method, adding amine polymers or silane coupling agents during the self-polymerization process of the surface modifier. Components in the amine polymers or silane coupling agents can enter and accumulate in the self-polymerized coating. For silane coupling agents, the surface modifier adheres to the fiber surface and introduces phenolic hydroxyl groups. Silane in the silane coupling agent hydrolyzes to generate silanols, and then a dehydration reaction occurs between the phenolic and silanic hydroxyl groups, forming long chains with alkenyl and hydrocarbon groups on their surface. These chains achieve effective adsorption through hydrogen bonds with the functional groups of asphalt, increasing the fiber's specific surface area and roughness, allowing more asphalt to be adsorbed onto the fiber. On the surface of the fiber, the asphalt and the fiber are interconnected to form a network skeleton structure, which enhances the stability of the overall structure. For amine compounds, the catechol and pyrogallol groups can be oxidized to catechol or pyrogallol. Quinones have high reactivity, which allows amine compounds to undergo Michael addition reactions or interactions such as hydrogen bonding, π-π superposition, van der Waals forces, and coordination bonds with surface modifier compounds, directly anchoring them to the surface of ceramic fibers. This enhances the hydrophobicity of the fiber surface, tightly binds with asphalt molecules, and improves the water stability of the asphalt mixture.

[0041] After surface modification, ceramic fibers can absorb more asphalt, increasing the toughness and crack resistance of asphalt mixtures and further enhancing the bridging and toughening effect of fibers in asphalt mixture systems. The addition of modified fibers can effectively connect various parts of the asphalt mixture system, resist softening and deformation caused by high temperatures, and improve the high-temperature stability of asphalt mixtures.

[0042] This invention modifies mineral powder using titanate coupling agents or silane coupling agents. These agents are amphoteric compounds combining inorganic and organic groups. The inorganic groups can firmly coat the calcium carbonate surface through chemical bonds, increasing its specific surface area. Simultaneously, the organic groups react with asphalt, allowing these two materials with completely different polarities to be tightly bonded together, enabling the functional mineral powder to fully exert its function within the asphalt matrix. A protective coupling agent film is generated on the mineral powder surface through chemical grafting, increasing the specific surface area of ​​the mineral powder without compromising its functionality. Titanate coupling agents, as a novel type of organic coupling agent, dissolve in water. After the alkyl groups are released, they can polymerize with the hydroxyl groups on the mineral powder surface, forming an organic active monolayer on the surface through chemical bonding theory. This monolayer increases the surface roughness of the mineral powder, providing better hydrophobic properties and stronger interfacial bonding with asphalt and fibers.

[0043] Ceramic fibers are commonly used as refractory materials due to their advantages such as high modulus, low density, high heat resistance, low thermal conductivity, high tensile strength, and resistance to mechanical vibration. Furthermore, ceramic fibers remain undecomposed and undamaged under acidic and alkaline environments, and do not age or oxidize under various forms of thermal and electromagnetic radiation, making them chemically stable fibers that meet the basic requirements for use as road materials. In addition, due to their excellent thermal insulation and high-temperature insulation properties, they can serve as road additives, providing a certain degree of thermal insulation, reducing cracks caused by temperature stress in the road surface, lowering the internal temperature of the road surface in summer, and improving the high-temperature performance of the road surface. Attached Figure Description

[0044] Figure 1 XPS analysis images of the modified spun ceramic fibers described in Examples 1-3; where a represents Example 1, b represents Example 2, and c represents Example 3.

[0045] Figure 2 XPS energy dispersive spectroscopy (EDS) spectra of the modified spun ceramic fibers described in Examples 1-3; where a represents Example 1, b represents Example 2, and c represents Example 3.

[0046] Figure 3 The images shown are infrared analysis diagrams of the modified mineral powders described in Examples 1-3; where a represents Example 1, b represents Example 2, and c represents Example 3.

[0047] Figure 4 SEM images of unmodified spun ceramic fiber (a) and modified spun ceramic fibers described in Examples 1-3 (b-d, respectively). Detailed Implementation

[0048] In this invention, the aggregate used is basalt, purchased from Zouping Basalt Co., Ltd., and the aggregate contains the following particle size distribution by mass ratio: 10-15mm: 5-10mm: 0-5mm = 20-21: 23-25: 31-33; the mineral powder used is purchased from Hongwan Mining Co., Ltd.; the asphalt used is 70# base asphalt, purchased from Shandong Huaji Co., Ltd.; the asphalt-aggregate ratio of the mineral aggregate to the 70# base asphalt is 5.1%. The spun ceramic fiber is purchased from Zhejiang Weiye Crystal Fiber Co., Ltd., with a length of 3mm. The plasma device is a TZ-2 type microwave plasma device, purchased from Shenzhen Puman Technology Co., Ltd. Red mud powder is purchased from Jinrun Materials Co., Ltd. Phosphogypsum is purchased from Jinrun Materials Co., Ltd.

[0049] In this invention, the overall gradation pass rate of the mineral materials (aggregates and mineral powder) is as shown in Table 1 below:

[0050] Table 1

[0051]

[0052] In this invention, ceramic fibers can improve the compressive strength, splitting tensile strength, and flexural strength of concrete to varying degrees. Simultaneously, ceramic fibers can improve the high-temperature performance and water stability of asphalt mixtures. Polyphenol modification is characterized by its simplicity, mild reaction conditions, lack of fiber surface damage, and environmental friendliness. Mineral powder fillers are important filler components in asphalt mixtures, capable of reacting with asphalt to form asphalt mastic, and are the most important primary dispersion system in asphalt concrete mixtures. Therefore, the surface properties of mineral powder have a significant impact on the overall performance and lifespan of asphalt mixtures. This invention improves the high-temperature stability and water stability of asphalt mixtures by combining spun ceramic fibers with polyphenolic compounds, amine polymers, or silane coupling agents, and by combining mineral powder with titanate coupling agents or silane coupling agents, using these as the main components of asphalt mixtures.

[0053] Other materials used in this invention, unless otherwise stated, are commercially available. Other terms used in this invention, unless otherwise specified, generally have the meanings commonly understood by those skilled in the art. The invention is further described in detail below with reference to specific embodiments and data. The following embodiments are merely illustrative and not intended to limit the scope of the invention in any way.

[0054] Example 1

[0055] This embodiment provides the preparation of isocarboxin / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane modified spun ceramic fibers and isopropyl dioleoyloxytitanate modified mineral powder asphalt mixture. The specific implementation process is as follows:

[0056] (1) Preparation of isocarboxin / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane modified spun ceramic fibers

[0057] 50g of spun ceramic fiber was ultrasonically cleaned and dried in a 60℃ oven for 10 hours. It was then removed and placed in a plasma surface treatment tank for pretreatment. The pretreatment conditions were: argon atmosphere, treatment time 6 minutes, temperature 35℃, pressure 14.5 Pa, and flow rate 15 mL / min. The fiber was then sealed and stored. 0.6g of isocarboxylic acid was dissolved in 150 mL of isopropanol, and the pH was adjusted to 8.5 with 0.1 mol / L sodium hydroxide solution. The solution was magnetically stirred for 15 minutes at room temperature to obtain the isocarboxylic acid solution. Subsequently, 0.2 g of N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane was added to the isokine solution to obtain an isokine / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane solution. The plasma-treated spun ceramic fibers were immersed in the isokine / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane solution and sonicated for 30 min, then allowed to stand for 4 h. The treated spun ceramic fibers were then removed, rinsed repeatedly with deionized water to remove excess reagents, and then dried at 80℃ for 6 h to obtain isokine / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane modified spun ceramic fibers.

[0058] (2) Preparation of modified mineral powder

[0059] Dissolve 1.2 g of isopropyl dioleoyl oxytitanate in 500 mL of anhydrous ethanol and let stand for 2 h. Then add 320 g of red mud powder and stir with an electric mixer for 30 min. Subsequently, dry the modified red mud powder in a 70 °C oven to obtain isopropyl dioleoyl oxytitanate-modified red mud powder, i.e., modified mineral powder, for later use.

[0060] (3) Preparation of modified asphalt mixture

[0061] The aggregate particle size distribution is as follows: 10-15mm 2080g, 5-10mm 2400g; 0-5mm 3200g. The aggregate and 320g of isopropyl dioleoyl oxytitanate modified red mud mineral powder were preheated in an oven at 170℃. 408g of 70# base asphalt was placed in an oven at 145℃ for constant temperature preparation. The mixing pot was preheated to a mixing temperature of 160℃. The aggregate was added to the mixing device, followed by 50g of isocarboxin / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane modified spun ceramic fiber, which was dry-mixed for 50s. Then, 70# base asphalt was added and mixed for 90s. Finally, isopropyl dioleoyl oxytitanate modified red mud mineral powder was added and mixed for another 90s to obtain the modified asphalt mixture.

[0062] Example 2

[0063] This embodiment provides the preparation of a mixture of salvianolic acid B / polyethyleneimine modified spun ceramic fiber and vinyltris(β-methoxyethoxy)silane modified mineral powder asphalt. The specific implementation process is as follows:

[0064] (1) Preparation of spun ceramic fibers modified with salvianolic acid B / polyethyleneimine:

[0065] 50g of spun ceramic fiber was ultrasonically cleaned and dried in a 60℃ oven for 10 hours. It was then removed and placed in a plasma surface treatment tank for pretreatment. The pretreatment conditions were: argon atmosphere, treatment time 10 min, temperature 25℃, pressure 14.5 Pa, and flow rate 15 mL / min. The fiber was then sealed and stored. 0.4g of salvianolic acid B was dissolved in 150 mL of chloroform, and the pH was adjusted to 8.5 with 0.1 mol / L ethylenediamine solution. The solution was magnetically stirred for 15 min at room temperature to obtain salvianolic acid B solution. Subsequently, 0.3g of polyethyleneimine was added to the salvianolic acid B solution to obtain salvianolic acid B / polyethyleneimine solution. The plasma-treated spun ceramic fiber was immersed in the salvianolic acid B / polyethyleneimine solution and sonicated for 30 minutes, then allowed to stand for 4 hours. The treated spun ceramic fiber was then removed, rinsed repeatedly with deionized water to remove excess reagent, and then placed in a 70℃ oven for high-temperature drying for 6 hours to obtain salvianolic acid B / polyethyleneimine spun ceramic fiber.

[0066] (2) Preparation of modified mineral powder

[0067] Prepare a solution by mixing 1.4 g of vinyltris(β-methoxyethoxy)silane, 650 mL of anhydrous ethanol, and 250 mL of deionized water. Let the solution stand for 2 hours, then add 320 g of basalt powder and stir with an electric mixer for 30 minutes. The modified basalt powder is then dried in a 70°C oven to obtain vinyltris(β-methoxyethoxy)silane-modified basalt powder, i.e., modified mineral powder, for later use.

[0068] (3) Preparation of asphalt mixture

[0069] The aggregate particle size distribution is as follows: 10-15mm 2080g, 5-10mm 2400g; 0-5mm 3200g. The aggregate and 320g of vinyltris(β-methoxyethoxy)silane-modified basalt mineral powder were preheated in an oven at 170℃. 408g of 70# base asphalt was placed in an oven at 145℃ for constant temperature preparation. The mixing pot was preheated to a mixing temperature of 160℃. The aggregate was added to the mixing device, followed by 50g of salvianolic acid B / polyethyleneimine spun ceramic fiber, which was dry-mixed for 50s. Then, 70# base asphalt was added and mixed for 90s. Finally, vinyltris(β-methoxyethoxy)silane-modified basalt mineral powder was added and mixed for another 90s to obtain the modified asphalt mixture.

[0070] Example 3

[0071] This embodiment provides the preparation of a mineral powder asphalt mixture modified with tert-butylcatechol / γ-methacryloyloxypropyltrimethoxysilane-modified spun ceramic fibers and monoalkoxy unsaturated fatty acid titanate. The specific implementation process is as follows:

[0072] (1) Preparation of p-tert-butylcatechol / γ-methacryloyloxypropyltrimethoxysilane modified spun ceramic fibers:

[0073] 50g of spun ceramic fiber was ultrasonically cleaned and dried in a 60℃ oven for 10 hours. It was then removed and placed in a plasma surface treatment tank for plasma pretreatment. The pretreatment conditions were: argon atmosphere, treatment time 5 min, temperature 40℃, pressure 14.5 Pa, and flow rate 15 mL / min. The fiber was then sealed and stored. 1g of p-tert-butylcatechol was dissolved in 180 mL of dimethylformamide, and the pH was adjusted to 8.5 with 0.1 mol / L sodium hydroxide solution. The solution was magnetically stirred for 15 min at room temperature to obtain a p-tert-butylcatechol solution. Subsequently, 0.4 g of γ-methacryloxypropyltrimethoxysilane was added to the p-tert-butylcatechol solution to obtain a p-tert-butylcatechol / γ-methacryloxypropyltrimethoxysilane solution. The plasma-treated spun ceramic fiber was immersed in the p-tert-butylcatechol / γ-methacryloxypropyltrimethoxysilane solution and sonicated for 30 min, then allowed to stand for 4 h. The treated spun ceramic fiber was then removed, rinsed repeatedly with deionized water to remove excess reagent, and then placed in a 70℃ oven for high-temperature drying for 6 h to obtain p-tert-butylcatechol / γ-methacryloxypropyltrimethoxysilane modified spun ceramic fiber.

[0074] (2) Preparation of modified mineral powder

[0075] Dissolve 1.8 g of monoalkoxyunsaturated fatty acid titanate in 600 mL of anhydrous ethanol and let stand for 2 h. Then add 320 g of phosphogypsum powder and stir with an electric mixer for 30 min. Subsequently, dry the modified phosphogypsum mineral powder in a 70 °C oven to obtain monoalkoxyunsaturated fatty acid titanate modified phosphogypsum mineral powder, i.e., modified mineral powder, for later use.

[0076] (3) Preparation of modified asphalt mixture

[0077] The aggregate particle size distribution is as follows: 10-15mm 2080g, 5-10mm 2400g; 0-5mm 3200g. The aggregate and 320g of monoalkoxy unsaturated fatty acid titanate modified phosphogypsum mineral powder were preheated in an oven at 170℃. 408g of 70# base asphalt was placed in an oven at 145℃ for constant temperature preparation. The mixing pot was preheated to a mixing temperature of 160℃. The aggregate was added to the mixing device, followed by 50g of p-tert-butylcatechol / γ-methacryloyloxypropyltrimethoxysilane modified spun ceramic fiber, which was dry-mixed for 50s. Then, 70# base asphalt was added and mixed for 90s. Finally, monoalkoxy unsaturated fatty acid titanate modified phosphogypsum mineral powder was added and mixed for another 90s to obtain the modified asphalt mixture.

[0078] The microscopic analysis of the materials described in Examples 1-3 above is as follows:

[0079] Figure 1 XPS analysis images of the modified spun ceramic fibers described in Examples 1-3 are shown, where a represents Example 1, b represents Example 2, and c represents Example 3. The images show that the surface of the spun silicon carbide ceramic fibers is mainly composed of elements such as C, O, and Si. After self-polymerization coating with isocarboxylic acid B and p-tert-butylcatechol, the N element content and N / C ratio increase, while the Si and O element content and O / C ratio decrease. This is due to the uniform coating of isocarboxylic acid B and p-tert-butylcatechol on the fiber surface. C1s and N1s further demonstrate the relationship between chemical bonds and chemical structures in the isocarboxylic acid / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane modified spun ceramic fibers, salvianolic acid B / polyethyleneimine modified spun ceramic fibers, or p-tert-butylcatechol / γ-methacryloyloxypropyltrimethoxysilane modified spun ceramic fiber samples.

[0080] Figure 2 The images show XPS energy dispersive spectroscopy (EDS) analysis results of the modified spun ceramic fibers described in Examples 1-3; where a represents Example 1, b represents Example 2, and c represents Example 3. From... Figure 2 As shown in (a), the C1s curve on the surface of the isocarboxin / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane modified spun ceramic fiber can be fitted with three peaks. The characteristic peaks at 284.7, 286.4, and 288.8 eV represent the C-C bond, CO bond, and OC=O bond, respectively. Figure 2 As shown in (b), the C1s peak on the surface of the salvianolic acid B / polyethyleneimine modified spun ceramic fiber increases at the 285.1 eV position, while the contents of CC and CO bonds decrease and the contents of OC=O bonds increase. Figure 2As shown in (c), the types of chemical bonds in the C1s peak of the spun ceramic fiber modified with tert-butylcatechol / γ-methacryloxypropyltrimethoxysilane are basically the same as those in the modified fibers mentioned above, but their contents differ. Overall, the contents of CN bonds, CO bonds, and OC=O are all increased in the spun ceramic fibers modified with isocarboxin / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, salvianolic acid B / polyethyleneimine, or tert-butylcatechol / γ-methacryloxypropyltrimethoxysilane. This is because the co-deposition chemical process introduces amino and oxygen-containing functional groups, leading to an increase in CN, CO, and OC=O bonds. Therefore, the surface chemical activity of the spun ceramic fiber after co-deposition coating is significantly increased, which is beneficial to the interfacial bonding between the spun ceramic fiber and asphalt.

[0081] Figure 3 The images show the FT-IR analysis results of the modified mineral powders described in Examples 1-3, where a represents Example 1, b represents Example 2, and c represents Example 3. From... Figure 3 As can be seen in (a), isopropyl dioleoyl oxytitanate modified mineral powder at 1430 cm⁻¹ -1 (Antisymmetric stretching vibration), 1085cm -1 (Symmetrical stretching vibration), 870cm -1 (out-of-plane bending vibration) and 710cm -1 (In-plane bending vibration peak) shows a typical absorption peak characteristic of calcium carbonate; mineral powder at 3623 cm⁻¹ -1 The absorption peak (the stretching vibration absorption peak of the hydroxyl group -OH) is due to the hydroxyl groups on its surface and the moisture in the test environment. From Figure 3 As can be seen in (b), after the mineral powder was modified with vinyltris(β-methoxyethoxy)silane, it was located at 2850 cm⁻¹. -1 and 2920cm -1 Peaks of both symmetric and antisymmetric stretching vibrations of methylene CH2 alkane appeared at the surface. After surface modification, the weak acidity of vinyltris(β-methoxyethoxy)silane neutralized the weak basicity of the hydroxyl groups on the mineral powder surface, resulting in complete coverage of the mineral powder surface by vinyltris(β-methoxyethoxy)silane. The long-chain alkane modification of vinyltris(β-methoxyethoxy)silane on the surface of the modified mineral powder completes the modification of the mineral powder by vinyltris(β-methoxyethoxy)silane. Therefore, vinyltris(β-methoxyethoxy)silane was successfully coated onto the surface of the mineral powder. Figure 3 As can be seen in (c), the monoalkoxy unsaturated fatty acid titanate modified mineral powder at 2855 cm⁻¹ -1 (symmetric stretching vibration) and 2952cm -1The presence of a characteristic peak of an organophilic functional group at the (antisymmetric stretching vibration peak) indicates that the titanate coupling agent has been successfully coated onto the surface of the mineral powder. This shows that the inorganic end of the amphoteric compound monoalkoxy unsaturated fatty acid titanate reacts chemically with the hydroxyl groups on the surface of the mineral powder and is adsorbed onto the surface of the mineral powder, while its organic end is exposed, thereby changing the surface properties of the mineral powder and making it oleophilic and hydrophobic.

[0082] Figure 4 The images show SEM images of the spun ceramic fibers before and after modification. In the image, a represents the unmodified spun ceramic fiber, and b to d represent the modified fibers from Examples 1 to 3, respectively. Figure 4 As can be seen in (a), the original spun ceramic fiber surface is smooth and free of any adhering material. Figure 4 As can be seen in (b), the surface of the spun ceramic fibers modified with isocarboxin / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane becomes rougher, exhibiting uneven defects. Isocarboxin / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane is co-deposited on the fiber surface, increasing both roughness and specific surface area. Figure 4 As can be seen in (c), the surface of the spun ceramic fiber modified with salvianolic acid B / polyethyleneimine is no longer smooth, and its roughness increases compared to the original spun ceramic fiber. From Figure 4 As can be seen in (d), the surface of the spun ceramic fiber modified with p-tert-butylcatechol / γ-methacryloxypropyltrimethoxysilane is effectively improved, and the roughness and specific surface area are greatly increased.

[0083] Comparative Example 1

[0084] This comparative example prepared isocarboxin / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane modified spun ceramic fiber asphalt mixture. The difference from Example 1 is that the mineral powder was not modified in this comparative example; the remaining steps were the same as in Example 1. The specific implementation process is as follows:

[0085] (1) Preparation of isocarboxin / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane modified spun ceramic fibers

[0086] 50g of spun ceramic fiber was ultrasonically cleaned and dried in a 60℃ oven for 10 hours. It was then removed and placed in a plasma surface treatment tank for pretreatment. The pretreatment conditions were: argon atmosphere, treatment time 6 minutes, temperature 35℃, pressure 14.5 Pa, and flow rate 15 mL / min. The fiber was then sealed and stored. 0.6g of isocarboxylic acid was dissolved in 150 mL of isopropanol, and the pH was adjusted to 8.5 with 0.1 mol / L sodium hydroxide solution. The solution was magnetically stirred for 15 minutes at room temperature to obtain the isocarboxylic acid solution. Subsequently, 0.2 g of N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane was added to the isokine solution to obtain an isokine / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane solution. The plasma-treated spun ceramic fibers were immersed in the isokine / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane solution and sonicated for 30 min, then allowed to stand for 4 h. The treated spun ceramic fibers were then removed, rinsed repeatedly with deionized water to remove excess reagents, and then dried at 80℃ for 6 h to obtain isokine / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane modified spun ceramic fibers.

[0087] (2) Preparation of modified asphalt mixture

[0088] The aggregate particle size distribution is as follows: 10-15mm 2080g, 5-10mm 2400g; 0-5mm 3200g. The aggregate and 320g of red mud powder were preheated in an oven at 170℃. 408g of 70# base asphalt was placed in an oven at 145℃ for constant temperature preparation. The mixing pot was preheated to a mixing temperature of 160℃. The aggregate was added to the mixing device, followed by 50g of isocarboxin / N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane modified spun ceramic fiber, which was dry-mixed for 50s. Then, 70# base asphalt was added and mixed for 90s. Finally, red mud powder was added and mixed for another 90s to obtain the modified asphalt mixture.

[0089] Comparative Example 2

[0090] This comparative example prepared a spun ceramic fiber asphalt mixture modified with salvianolic acid B / polyethyleneimine. The difference from Example 2 is that the mineral powder was not modified in this comparative example; the remaining steps were the same as in Example 2. The specific implementation process is as follows:

[0091] (1) Preparation of spun ceramic fibers modified with salvianolic acid B / polyethyleneimine:

[0092] 50g of spun ceramic fiber was ultrasonically cleaned and dried in a 60℃ oven for 10 hours. It was then removed and placed in a plasma surface treatment tank for pretreatment. The pretreatment conditions were: argon atmosphere, treatment time 10 min, temperature 25℃, pressure 14.5 Pa, and flow rate 15 mL / min. The fiber was then sealed and stored. 0.4g of salvianolic acid B was dissolved in 150 mL of chloroform, and the pH was adjusted to 8.5 with 0.1 mol / L ethylenediamine solution. The solution was magnetically stirred for 15 min at room temperature to obtain salvianolic acid B solution. Subsequently, 0.3g of polyethyleneimine was added to the salvianolic acid B solution to obtain salvianolic acid B / polyethyleneimine solution. The plasma-treated spun ceramic fiber was immersed in the salvianolic acid B / polyethyleneimine solution and sonicated for 30 minutes, then allowed to stand for 4 hours. The treated spun ceramic fiber was then removed, rinsed repeatedly with deionized water to remove excess reagent, and then placed in a 70℃ oven for high-temperature drying for 6 hours to obtain salvianolic acid B / polyethyleneimine spun ceramic fiber.

[0093] (2) Preparation of modified asphalt mixture

[0094] The aggregate particle size distribution is as follows: 10-15mm 2080g, 5-10mm 2400g; 0-5mm 3200g. The aggregate and 320g of basalt powder were preheated in an oven at 170℃; 408g of 70# base asphalt was placed in an oven at 145℃ for constant temperature preparation; the mixing pot was preheated to a mixing temperature of 160℃; the aggregate was added to the mixing device, followed by 50g of salvianolic acid B / polyethyleneimine spun ceramic fiber, which was dry-mixed for 50s, then 70# base asphalt was added and mixed for 90s, and finally basalt powder was added and mixed for another 90s to obtain the modified asphalt mixture.

[0095] Comparative Example 3

[0096] This comparative example prepared a p-tert-butylcatechol / γ-methacryloyloxypropyltrimethoxysilane modified spun ceramic fiber asphalt mixture. The difference from Example 3 is that the mineral powder was not modified in this comparative example; the remaining steps are the same as in Example 3. The specific implementation process is as follows:

[0097] (1) Preparation of p-tert-butylcatechol / γ-methacryloyloxypropyltrimethoxysilane modified spun ceramic fibers:

[0098] 50g of spun ceramic fiber was ultrasonically cleaned and dried in a 60℃ oven for 10 hours. It was then removed and placed in a plasma surface treatment tank for plasma pretreatment. The pretreatment conditions were: argon atmosphere, treatment time 5 min, temperature 40℃, pressure 14.5 Pa, and flow rate 15 mL / min. The fiber was then sealed and stored. 1g of p-tert-butylcatechol was dissolved in 180 mL of dimethylformamide, and the pH was adjusted to 8.5 with 0.1 mol / L sodium hydroxide solution. The solution was magnetically stirred for 15 min at room temperature to obtain a p-tert-butylcatechol solution. Subsequently, 0.4 g of γ-methacryloxypropyltrimethoxysilane was added to the p-tert-butylcatechol solution to obtain a p-tert-butylcatechol / γ-methacryloxypropyltrimethoxysilane solution. The plasma-treated spun ceramic fiber was immersed in the p-tert-butylcatechol / γ-methacryloxypropyltrimethoxysilane solution and sonicated for 30 min, then allowed to stand for 4 h. The treated spun ceramic fiber was then removed, rinsed repeatedly with deionized water to remove excess reagent, and then placed in a 70℃ oven for high-temperature drying for 6 h to obtain p-tert-butylcatechol / γ-methacryloxypropyltrimethoxysilane modified spun ceramic fiber.

[0099] (2) Preparation of modified asphalt mixture

[0100] The aggregate particle size distribution is as follows: 10-15mm 2080g, 5-10mm 2400g; 0-5mm 3200g. The aggregate and 320g of phosphogypsum powder were preheated in an oven at 170℃. 408g of 70# base asphalt was placed in an oven at 145℃ for constant temperature preparation. The mixing pot was preheated to a mixing temperature of 160℃. The aggregate was added to the mixing device, followed by 50g of p-tert-butylcatechol / γ-methacryloyloxypropyltrimethoxysilane modified spun ceramic fiber, which was dry-mixed for 50s. Then, 70# base asphalt was added and mixed for 90s. Finally, phosphogypsum powder was added and mixed for another 90s to obtain the modified asphalt mixture.

[0101] Comparative Example 4

[0102] This comparative example prepared an isopropyl dioleoyl oxytitanate-modified red mud mineral powder asphalt mixture. The difference from Example 1 is that this comparative example did not modify the spun ceramic fibers; the other steps were the same as in Example 1. The specific process is as follows:

[0103] (1) Preparation of modified mineral powder

[0104] Dissolve 1.2 g of isopropyl dioleoyl oxytitanate in 500 mL of anhydrous ethanol and let stand for 2 h. Then add 320 g of red mud powder and stir with an electric mixer for 30 min. Subsequently, dry the modified red mud powder in a 70 °C oven to obtain isopropyl dioleoyl oxytitanate-modified red mud powder, i.e., modified mineral powder, for later use.

[0105] (2) Preparation of modified asphalt mixture

[0106] The particle size distribution of the aggregate is as follows: 10-15mm 2080g, 5-10mm 2400g; 0-5mm 3200g. The aggregate and 320g of isopropyl dioleoyl oxytitanate modified red mud mineral powder were preheated in an oven at 170℃. 408g of 70# base asphalt was placed in an oven at 145℃ and kept at a constant temperature. The mixing pot was preheated to a mixing temperature of 160℃. The aggregate was added to the mixing device, followed by 50g of spun ceramic fiber and dry-mixed for 50s. Then, 70# base asphalt was added and mixed for 90s. Finally, isopropyl dioleoyl oxytitanate modified red mud mineral powder was added and mixed for another 90s to obtain the modified asphalt mixture.

[0107] Comparative Example 5

[0108] This comparative example prepared a vinyltris(β-methoxyethoxy)silane-modified basalt mineral powder asphalt mixture. The difference from Example 2 is that this comparative example did not modify the spun ceramic fibers; the steps were the same as in Example 2. The specific implementation process is as follows:

[0109] (1) Preparation of modified mineral powder

[0110] Prepare a solution by mixing 1.4 g of vinyltris(β-methoxyethoxy)silane, 650 mL of anhydrous ethanol, and 250 mL of deionized water. Let the solution stand for 2 hours, then add 320 g of basalt powder and stir with an electric mixer for 30 minutes. The modified basalt powder is then dried in a 70°C oven to obtain vinyltris(β-methoxyethoxy)silane-modified basalt powder, i.e., modified mineral powder, for later use.

[0111] (2) Preparation of modified asphalt mixture

[0112] The aggregate particle size distribution is as follows: 10-15mm 2080g, 5-10mm 2400g; 0-5mm 3200g. The aggregate and 320g of vinyltris(β-methoxyethoxy)silane-modified basalt mineral powder were preheated in an oven at 170℃. 408g of 70# base asphalt was placed in an oven at 145℃ for constant temperature preparation. The mixing pot was preheated to a mixing temperature of 160℃. The aggregate was added to the mixing device, followed by 50g of spun ceramic fiber and dry-mixed for 50s. Then, 70# base asphalt was added and mixed for 90s. Finally, vinyltris(β-methoxyethoxy)silane-modified basalt mineral powder was added and mixed for another 90s to obtain the modified asphalt mixture.

[0113] Comparative Example 6

[0114] This comparative example prepared a monoalkoxy unsaturated fatty acid titanate-modified phosphogypsum powder pitch mixture. The difference from Example 3 is that this comparative example did not modify the spun ceramic fibers; the remaining steps were the same as in Example 3. The specific implementation process is as follows:

[0115] (1) Preparation of modified mineral powder

[0116] Dissolve 1.8 g of monoalkoxyunsaturated fatty acid titanate in 600 mL of anhydrous ethanol and let stand for 2 h. Then add 320 g of phosphogypsum powder and stir with an electric mixer for 30 min. Subsequently, dry the modified phosphogypsum mineral powder in a 70 °C oven to obtain monoalkoxyunsaturated fatty acid titanate modified phosphogypsum mineral powder, i.e., modified mineral powder, for later use.

[0117] (2) Preparation of modified asphalt mixture

[0118] The aggregate particle size distribution is as follows: 10-15mm 2080g, 5-10mm 2400g; 0-5mm 3200g. The aggregate and 320g of monoalkoxy unsaturated fatty acid titanate modified phosphogypsum mineral powder were preheated in an oven at 170℃. 408g of 70# base asphalt was placed in an oven at 145℃ for constant temperature preparation. The mixing pot was preheated to a mixing temperature of 160℃. The aggregate was added to the mixing device, followed by 50g of spun ceramic fiber and dry-mixed for 50s. Then, 70# base asphalt was added and mixed for 90s. Finally, monoalkoxy unsaturated fatty acid titanate modified phosphogypsum mineral powder was added and mixed for another 90s to obtain the modified asphalt mixture.

[0119] I. Road Performance Testing

[0120] The road performance of the asphalt mixtures in the above implementation cases was tested according to the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011), and the test results are shown in Table 1.

[0121] Table 1

[0122]

[0123] In the dynamic stability test of asphalt mixtures, the dynamic stability of Examples 1-3 increased by 26%, 20%, and 28.6% respectively compared to Comparative Examples 4-6. This is because after modification, the asphalt adsorption capacity of the spun ceramic fibers increased, improving their compatibility with asphalt. The fibers formed a denser network skeleton structure in the mixture, acting as reinforcement and enhancing the asphalt mixture's resistance to rutting. The modified fibers exhibited superior reinforcing ability. At high temperatures, asphalt mixtures are prone to softening and deformation, leading to rutting and unstable vehicle driving. The addition of fibers can increase the mixture's resistance to deformation, reduce asphalt fluidity, and lower the risk of pavement deformation. The modified fibers have a larger specific surface area, allowing them to adsorb more asphalt, increasing the mixture's toughness and crack resistance, and further enhancing the bridging and toughening effect of the fibers in the asphalt mixture system. The addition of modified fibers can effectively connect various parts of the asphalt mixture system, resisting softening and deformation caused by high temperatures, improving pavement durability, and increasing the dynamic stability of the mixture. Compared to Comparative Examples 1-3, Examples 1-3 showed a significant improvement in dynamic stability. This is because, in addition to fiber modification, the mineral powder surface in these examples was completely coated with a coupling agent. The coupling agent firmly adsorbed onto the surface, forming a dense film, which altered the weak oleophilic properties of the mineral powder surface, enhancing its oleophilicity and making it easier to disperse evenly in asphalt. When the modified mineral powder was added to the asphalt mixture, the organic molecular layer formed by the coupling agent on the surface of the mineral powder linked the mineral powder to the asphalt, improving the compatibility between the asphalt and mineral powder, increasing the cohesiveness of the asphalt mastic, thereby enhancing the adhesion between aggregates and improving the high-temperature stability of asphalt pavement.

[0124] In the tests of asphalt mixture stability, water immersion Marshall stability, and freeze-thaw splitting tensile strength residual ratio, Examples 1-3 showed significant improvements compared to Examples 4-6. This is because the modified spun ceramic fibers have added alkenyl and hydrocarbon groups to their surface, enhancing their oleophilicity. The asphalt adhering to the fiber surface forms a good wetting interface with the surrounding asphalt, effectively reducing the formation of crack surfaces. This interlocking structure allows the fibers to connect with each other, forming a skeletal structure that enhances the overall structural stability. The spatial network structure formed by the fibers in the asphalt not only stabilizes the aggregate and reduces relative slippage between aggregates, but also effectively transfers and dissipates stress, thereby reducing stress concentration and preventing crack development, thus improving the water stability of the asphalt mixture. Compared with Comparative Examples 1-3, the water stability of Examples 1-3 was also significantly improved. This is because, in addition to fiber modification, the modified mineral powder in the examples had high activity. The wetting effect between the asphalt and the modified mineral powder enhanced the interfacial adsorption strength, improved the viscosity of the asphalt mortar, and made it firmly wrapped on the surface of the mineral material. It also increased the thickness of the structural asphalt film, effectively preventing water from entering the interface between the asphalt and the mineral material, and improving the anti-stripping properties between the two.

[0125] In the flexural strain test of asphalt mixtures, the flexural strain of Examples 1-3 increased by 31.1%, 22.6%, and 31.3% compared to Comparative Examples 4-6, respectively. This is because, under low-temperature conditions, the modified fibers significantly improve the interfacial adhesion of the asphalt mixture, enhancing its resistance to cracking. When the mixture is subjected to external loads, the toughening and crack-resistant effect of the modified fibers in the system can connect various parts of the system, effectively controlling crack propagation in the asphalt mixture, preventing crack formation and propagation, and enabling better bonding with asphalt to form stronger interfacial bond strength, increasing the adhesion and interaction between the fibers and asphalt. This helps to disperse stress and reduce crack propagation, improving the crack resistance of asphalt pavements under low-temperature conditions, thereby improving pavement durability, reducing cracks and damage, and extending the service life of asphalt pavements. Compared with Comparative Examples 1-3, Examples 1-3 show a significant improvement in flexural tensile strain. This is because, in addition to fiber modification, the modified mineral powder in the examples has a low oil absorption value and is hydrophobic and oleophilic, which can tightly bind the asphalt and aggregate together, effectively disperse and transfer the stress caused by external loads, avoid cracking failure due to stress concentration, and prevent crack propagation.

[0126] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing modified spun ceramic fiber asphalt mixture, characterized in that, Includes the following steps: Under high temperature conditions, aggregates are mixed with modified spun ceramic fibers and stirred; then base asphalt is added and stirred; finally, modified mineral powder is added and stirred to obtain modified spun ceramic fiber asphalt mixture. The aggregate is selected from one of basalt, granite, diabase, shale, limestone, and dolomite; the aggregate particle size distribution is as follows: 10-15mm 2000~2100 parts, 5-10mm 2300~2500 parts; 0-5mm 3100~3300 parts; the base asphalt is selected from 70# petroleum asphalt; The modified spun ceramic fiber is prepared by the following method: The spun ceramic fibers are subjected to plasma treatment; the surface modifier is dissolved in an organic solvent, and then the pH is adjusted to weakly alkaline using an alkaline solution to obtain a surface modifier solution; amine polymers or silane coupling agents are added to the surface modifier solution, and then the spun ceramic fibers are added and immersed in the reaction; after the reaction is completed, the spun ceramic fibers are taken out, rinsed, and dried to obtain modified spun ceramic fibers. In the preparation method of the modified spun ceramic fiber, the mass fractions of each component are as follows: The composition includes 50-60 parts of spun ceramic fiber, 0.4-1 part of surface modifier, 150-200 parts of organic solvent, and 0.1-0.4 parts of amine polymer or silane coupling agent. The spun ceramic fiber is selected from at least one of silicon carbide, aluminum silicate, alumina, and zirconium oxide fibers, and the fiber length is 3~5mm; The surface modifier is selected from one or more of the following: theaflavin-3-gallate, isoocanine, salvianolic acid B, 4-methylcatechol, chlorogenic acid, gallic acid, catechin gallate, p-tert-butylcatechol, dopamine, 5,6-dihydroxyindole, and 3,4-dihydroxyphenylacetic acid. The organic solvent is selected from at least one of isopropanol, acetonitrile, tetrahydrofuran, dimethylacetamide, ethyl acetate, methanol, dimethylformamide, chloroform, acetone, and dimethyl sulfoxide; The amine compounds are selected from tetraethylenepentamine, ethylenediamine, octadecylamine, aniline, N-propyl-1,3-diaminopropane, N-isopropyl-1,3-diaminopropane, N-cyclohexyl-1,3-diaminopropane, 3-(2-aminoethyl)aminopropylamine, bis(3-aminopropyl)amine, methylbis(3-aminopropyl)amine, N,N-dimethyldipropylenetriamine, N,N'-bis(3-aminopropyl)-1,3-propanediamine, 1,3 At least one of the following: propylenediamine, 1,4-butanediamine, lysine, cystamine, xylenediamine and tris(2-aminoethyl)amine, N-methyl-1,3-diaminopropane, 2-(3-aminopropylamino)ethanol, 2-[(4-aminophenyl)amino]benzoic acid, polyethyleneimine, piperidine, polypropylene glycol etheramine, N-(3-aminopropyl)-1,4-diaminobutane, polyethylene glycol etheramine, and 1,2-bis(3-aminopropylamino)ethane; The silane coupling agent is selected from one or more of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, methylvinyldimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, methacryloyloxypropylmethyldimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and γ-ureidopropyltrimethoxysilane. The alkaline solution is selected from one of sodium hydroxide, potassium hydroxide, and ammonia water, with a concentration of 0.1 mol / L; The modified mineral powder is obtained by modifying the mineral powder using titanate coupling agents or silane coupling agents.

2. The preparation method according to claim 1, characterized in that, When titanate coupling agents are used for modification, the preparation method of the modified mineral powder is as follows: Dissolve the titanate coupling agent in ethanol and let it stand; then add the mineral powder and stir; after stirring is finished, dry it to obtain the titanate coupling agent modified mineral powder. The mass fractions of each component are as follows: titanate coupling agent 1-2 parts, ethanol 400-700 parts, mineral powder 200-400 parts; The titanate coupling agent is selected from at least one of isopropyl dioleoyl oxytitanate, isopropyl dioleoyl oxy(dioctyl phosphate oxy) titanate, triisostearate titanate isopropyl, bis(dioctyl pyrophosphate) ethylene titanate, isopropyl tri(dioctyl pyrophosphate oxy) titanate, and monoalkoxy unsaturated fatty acid titanate. The mineral powder is selected from one of the following: basalt, S75 granulated blast furnace slag powder, fly ash, red mud, S95 granulated blast furnace slag powder, S105 granulated blast furnace slag powder, coal gangue powder, and phosphogypsum, with a particle size of less than 0.075 mm.

3. The preparation method according to claim 1, characterized in that, When silane coupling agents are used for modification, the preparation method of the modified mineral powder is as follows: Mix silane coupling agent, ethanol and water, and let stand; then add mineral powder and stir; after stirring is finished, dry to obtain silane coupling agent modified mineral powder; The mass fractions of each component are as follows: 1-2 parts silane coupling agent, 500-700 parts ethanol, 200-400 parts water, and 200-400 parts mineral powder; The silane coupling agent is selected from at least one of vinyltris(β-methoxyethoxy)silane, phenyltrimethoxysilane, 3-[2-(2-aminoethylamino)ethylamino]propyltrimethoxysilane, and phenyltriethoxysilane. The mineral powder is selected from one of the following: basalt, S75 granulated blast furnace slag powder, fly ash, red mud, S95 granulated blast furnace slag powder, S105 granulated blast furnace slag powder, coal gangue powder, and phosphogypsum, with a particle size of less than 0.075 mm.

4. The preparation method according to claim 1, characterized in that, The raw materials are selected from the following parts by weight: 7400-7900 parts of aggregate, 400-420 parts of base bitumen, 40-60 parts of modified spun ceramic fiber, and 300-350 parts of modified mineral powder.

5. The preparation method according to claim 1, characterized in that, The high temperature conditions are selected from 160~170℃.

6. Modified spun-fiber ceramic fiber asphalt mixture prepared by the method according to any one of claims 1 to 5.

7. The application of the modified spun-fiber ceramic fiber asphalt mixture according to claim 6 in the construction of vehicular road pavement.

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