High-performance basalt fiber asphalt mixture and preparation method thereof

Abstract

The invention relates to the technical field of asphalt mixtures, in particular to a high-performance basalt fiber asphalt mixture and a preparation method thereof. The preparation method of the high-performance basalt fiber asphalt mixture comprises the following steps: (1) heating basalt fibers and a silane coupling agent for reaction to obtain silane coupling agent modified basalt fibers; (2) adding catechin and pentaerythritol tetraglycidyl methacrylate into a solvent, then adding a catalyst, carrying out a heating reflux reaction, and collecting a product; (3) respectively adding products obtained in the step (1) and the step (2) into a solvent, then adding a coupling agent, and carrying out a heating reaction to obtain modified basalt fibers; (4) mixing and stirring the modified basalt fiber and aggregate to obtain a premix; and (5) adding asphalt into the premix, and uniformly stirring to obtain the product. The asphalt mixture disclosed by the invention has good water stability and cracking resistance, and the service life of an asphalt pavement is prolonged.

Description

Technical Field

[0001] This invention relates to the field of asphalt mixture technology, and in particular to a high-performance basalt fiber asphalt mixture and its preparation method. Background Technology

[0002] With the rapid development of my country's national economy and transportation sector, the scale and grade of road infrastructure have continued to expand, and traffic flow and axle loads have been increasing daily. This has placed more stringent demands on the performance, durability, and safety of road surfaces. Asphalt pavement, due to its advantages such as driving comfort, low noise, and ease of maintenance, has become the main pavement type for high-grade highways. However, during long-term use, it is susceptible to the effects of complex environmental factors and traffic loads, resulting in a series of defects such as aging, cracking, and water damage, which seriously affect the service life and performance of the pavement.

[0003] Currently, most asphalt pavement in my country adopts a dense-graded, low-voidity structure (such as AC type). This type of mixture typically has a void ratio controlled at around 4%, resulting in a dense structure with good durability and economy, and has been widely used in the past. However, its inherent defects are particularly pronounced in rainy areas: the low porosity and surface texture depth prevent surface water from draining quickly enough, easily forming a water film between tires and the road surface, causing water drift and splashing, significantly reducing driving safety. More seriously, the water retained in the pavement structure layer, under the repeated dynamic water pressure of vehicle loads, erodes the adhesion interface between asphalt and aggregates, causing the asphalt to harden and become brittle, reducing flexibility and significantly decreasing fatigue and crack resistance—the most significant water damage disease of asphalt pavements. To delay asphalt aging and improve water stability and crack resistance, fiber reinforcement technology has been widely introduced into asphalt mixtures. Among various fiber materials, basalt fiber has received widespread attention in recent years due to its excellent mechanical properties, high and low temperature stability, chemical corrosion resistance, and environmental friendliness. Basalt fiber is an inorganic fiber made from natural basalt through high-temperature melting and drawing. It has advantages such as high strength, high modulus, and good compatibility with asphalt. When added to asphalt mixtures, it can form a three-dimensional network structure in the matrix, acting as reinforcement and bridging, thereby effectively inhibiting crack propagation and improving the stability and crack resistance of the mixture.

[0004] However, the interfacial bonding between ordinary basalt fibers and the asphalt matrix remains insufficient. Furthermore, it lacks anti-aging and water damage stability, failing to effectively slow down the aging process of asphalt and extend the lifespan of asphalt pavements. Therefore, there is an urgent need to develop an asphalt mixture with good water stability, crack resistance, and fatigue resistance, which is of great significance for improving the overall performance of asphalt pavements. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the primary objective of this invention is to provide a high-performance basalt fiber asphalt mixture.

[0006] Another objective of this invention is to provide a method for preparing high-performance basalt fiber asphalt mixture. This method is simple to operate, plays an important role in industrial production, and is of great significance for promoting the development of road engineering materials.

[0007] The objective of this invention is achieved through the following technical solution: A method for preparing high-performance basalt fiber asphalt mixture includes the following steps: (1) Basalt fiber was added to a mixed solution of ethanol and water, and then a silane coupling agent was added. After heating and reacting, silane coupling agent modified basalt fiber was obtained for later use. (2) Add catechin and pentaerythritol tetramethacrylate to a solvent, then add a catalyst, heat under nitrogen protection and reflux to react, collect the product and set aside; (3) Take the basalt fiber modified by silane coupling agent in step (1) and the product in step (2) respectively, add them into N,N-dimethylformamide, add coupling agent, and heat to react to obtain modified basalt fiber. (4) The modified basalt fiber and aggregate are mixed and stirred to obtain a premix; (5) Add asphalt to the premix from step (4) and stir until homogeneous to obtain the final product.

[0008] Further, in step (1), the mass ratio of the basalt fiber, silane coupling agent, and mixed solution is 1:(0.3-0.5):(10-15); the silane coupling agent is KH-570, and the mixed solution is obtained by mixing ethanol and water in a volume ratio of 1:(2-3).

[0009] Furthermore, in step (1), the heating reaction is carried out at a temperature of 50-60°C for 3-5 hours.

[0010] Further, in step (2), the mass ratio of the catechin, pentaerythritol tetramethacrylate glycidyl ester, catalyst, and solvent is 1:(20-25):(55-60):(0.1-0.2).

[0011] Further, in step (2), the solvent is anhydrous ethanol, the catalyst is sodium hydroxide, and the reflux reaction time is 10-15 h.

[0012] Further, in step (3), the mass ratio of the basalt fiber modified with silane coupling agent in step (1), the product in step (2), the solvent, and the coupling agent is 60:(20-28):(1000-1300):(10-15); the coupling agent is vinyltriethoxysilane, and the solvent is N,N-dimethylformamide.

[0013] Furthermore, in step (3), the heating reaction is carried out at a temperature of 55-60°C for 4-5 hours.

[0014] Furthermore, in steps (4) and (5), the mass ratio of the asphalt, modified basalt fiber, and aggregate is 1:(0.05-0.1):(15-20).

[0015] Further, in step (5), the aggregate is divided into: a first aggregate with a particle size of 9-18 mm, a second aggregate with a particle size of 3-9 mm, and a third aggregate with a particle size of 0-3 mm; the mass ratio of the first aggregate, the second aggregate, and the third aggregate is 4:(5-6):(2-3); in step (5), the stirring temperature is 150-170℃.

[0016] The high-performance basalt fiber asphalt mixture of the present invention is prepared by the above-described preparation method.

[0017] The present invention has the following advantages over the prior art: 1. The basalt fiber added in this invention is first treated with a silane coupling agent to improve its surface activity and provide active sites for free radical copolymerization. Under an alkaline catalyst, multiple phenolic anions on the catechin molecule can simultaneously attack multiple epoxy groups on the pentaerythritol tetramethacrylate, resulting in a ring-opening reaction and forming multiple branched structures on the catechin, each branched structure ending in a methacrylate double bond. Under free radical initiation, the double bonds on the silane coupling agent-modified basalt fiber polymerize, forming a highly cross-linked three-dimensional network structure on the basalt fiber surface. This fixes the catechin on the basalt fiber surface, fully utilizing its antioxidant capacity and delaying the aging of asphalt mixtures. The modified basalt fiber exhibits good compatibility with asphalt, effectively preventing moisture from penetrating the asphalt mixture matrix interface, thereby significantly improving the asphalt mixture's resistance to water damage, increasing crack resistance, and extending the service life of asphalt pavements, resulting in good economic benefits.

[0018] 2. This invention provides a method for preparing high-performance basalt fiber asphalt mixture. This method is simple and convenient, and it develops a multifunctional asphalt mixture, which is of great significance for promoting the development of road engineering materials. Attached Figure Description

[0019] Figure 1 This is an electron microscope image of the modified basalt fiber obtained in Example 1 of the present invention. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field. Test methods in the following embodiments that do not specify specific experimental conditions are generally performed according to conventional experimental conditions or experimental conditions recommended by the manufacturer. Unless otherwise specified, the reagents and raw materials used in the present invention are commercially available.

[0021] In the embodiments and comparative examples of this invention, the basalt fibers have a diameter of 6-12µm and a length of 5-20mm; the asphalt is Grade 70 A asphalt; the aggregates are divided into: a first aggregate with a particle size of 9-18mm, a second aggregate with a particle size of 3-9mm, and a third aggregate with a particle size of 0-3mm.

[0022] Example 1 A method for preparing high-performance basalt fiber asphalt mixture includes the following steps: (1) Ethanol and water were mixed in a volume ratio of 1:3 to obtain a mixed solution; basalt fiber was added to the mixed solution, and then silane coupling agent KH-570 was added. The mass ratio of basalt fiber, KH-570 and mixed solution was 1:0.4:12. The mixture was heated to 55°C and reacted for 4 hours. After filtration, washing and drying, silane coupling agent modified basalt fiber was obtained for later use. (2) Add catechin and pentaerythritol tetramethacrylate glycidyl ester to anhydrous ethanol, and then add sodium hydroxide. The mass ratio of catechin, pentaerythritol tetramethacrylate glycidyl ester, sodium hydroxide and anhydrous ethanol is 1:22:58:0.15. Heat under nitrogen protection and reflux for 12 hours. After the reaction is completed, cool the reaction solution to room temperature, dialyze and then remove water by rotary evaporation. Collect the product for later use. (3) Take the basalt fiber modified with silane coupling agent in step (1) and the product in step (2) respectively, add them to N,N-dimethylformamide, and then add vinyltriethoxysilane. The mass ratio of the basalt fiber modified with silane coupling agent in step (1), the product in step (2), N,N-dimethylformamide, and vinyltriethoxysilane is 60:25:1200:13. Then react at 58℃ for 4.5h. After the reaction is completed, filter, wash, and dry to obtain modified basalt fiber. The electron micrograph of the obtained modified basalt fiber is shown in the figure. Figure 1 As shown.

[0023] (4) The modified basalt fiber and aggregate are mixed and stirred to obtain a premix; the aggregate is prepared by mixing the first aggregate, the second aggregate and the third aggregate in a mass ratio of 4:5.5:2.5; (5) Add asphalt to the premix in step (4) and stir evenly at 160°C. The mass ratio of asphalt, modified basalt fiber and aggregate is 1:0.08:18; and the mixture is obtained.

[0024] This embodiment also provides a high-performance basalt fiber asphalt mixture, which is prepared using the above-described preparation method.

[0025] Example 2 A method for preparing high-performance basalt fiber asphalt mixture includes the following steps: (1) Ethanol and water were mixed in a volume ratio of 1:2 to obtain a mixed solution; basalt fiber was added to the mixed solution, and then silane coupling agent KH-570 was added. The mass ratio of basalt fiber, KH-570 and mixed solution was 1:0.3:10. The mixture was heated to 50°C and reacted for 5 hours. After filtration, washing and drying, silane coupling agent modified basalt fiber was obtained for later use. (2) Add catechin and pentaerythritol tetramethacrylate glycidyl ester to anhydrous ethanol, and then add sodium hydroxide. The mass ratio of catechin, pentaerythritol tetramethacrylate glycidyl ester, sodium hydroxide and anhydrous ethanol is 1:20:55:0.1. Heat under nitrogen protection and reflux for 10 h. After the reaction is completed, cool the reaction solution to room temperature, dialyze and then remove water by rotary evaporation. Collect the product for later use. (3) Take the basalt fiber modified by the silane coupling agent in step (1) and the product in step (2) respectively and add them to N,N-dimethylformamide, and then add vinyltriethoxysilane. The mass ratio of the basalt fiber modified by the silane coupling agent in step (1), the product in step (2), N,N-dimethylformamide and vinyltriethoxysilane is 60:20:1000:10. Then react at 55°C for 5 hours. After the reaction is completed, filter, wash and dry to obtain modified basalt fiber. (4) The modified basalt fiber and aggregate are mixed and stirred to obtain a premix; the aggregate is prepared by mixing the first aggregate, the second aggregate and the third aggregate in a mass ratio of 4:5:2. (5) Add asphalt to the premix in step (4) and stir evenly at 150°C. The mass ratio of asphalt, modified basalt fiber and aggregate is 1:0.05:15; and the mixture is obtained.

[0026] This embodiment also provides a high-performance basalt fiber asphalt mixture, which is prepared using the above-described preparation method.

[0027] Example 3 A method for preparing high-performance basalt fiber asphalt mixture includes the following steps: (1) Ethanol and water were mixed in a volume ratio of 1:3 to obtain a mixed solution; basalt fiber was added to the mixed solution, and then silane coupling agent KH-570 was added. The mass ratio of basalt fiber, KH-570 and mixed solution was 1:0.5:15. The mixture was heated to 60°C and reacted for 3 hours. After filtration, washing and drying, silane coupling agent modified basalt fiber was obtained for later use. (2) Add catechin and pentaerythritol tetramethacrylate glycidyl ester to anhydrous ethanol, and then add sodium hydroxide. The mass ratio of catechin, pentaerythritol tetramethacrylate glycidyl ester, sodium hydroxide and anhydrous ethanol is 1:25:60:0.2. Heat under nitrogen protection and reflux for 15 h. After the reaction is completed, cool the reaction solution to room temperature, dialyze and then remove water by rotary evaporation. Collect the product for later use. (3) Take the basalt fiber modified by the silane coupling agent in step (1) and the product in step (2) respectively and add them to N,N-dimethylformamide, and then add vinyltriethoxysilane. The mass ratio of the basalt fiber modified by the silane coupling agent in step (1), the product in step (2), N,N-dimethylformamide and vinyltriethoxysilane is 60:28:1300:15. Then react at 60°C for 4 hours. After the reaction is completed, filter, wash and dry to obtain modified basalt fiber. (4) The modified basalt fiber and aggregate are mixed and stirred to obtain a premix; the aggregate is prepared by mixing the first aggregate, the second aggregate and the third aggregate in a mass ratio of 4:6:3. (5) Add asphalt to the premix in step (4) and stir evenly at 170°C. The mass ratio of asphalt, modified basalt fiber and aggregate is 1:0.1:20; and the mixture is obtained.

[0028] This embodiment also provides a high-performance basalt fiber asphalt mixture, which is prepared using the above-described preparation method.

[0029] Comparative Example 1 Comparative Example 1 is basically the same as Example 1, except that the modified basalt fiber in step (4) is replaced with the physical mixture of basalt fiber modified with silane coupling agent in step (1) and catechin.

[0030] Comparative Example 2 Comparative Example 2 is basically the same as Example 1, except that pentaerythritol tetramethacrylate glycidyl ester is replaced with glycidyl methacrylate.

[0031] Test case The permeability coefficient, Marshall stability, immersion residual stability, freeze-thaw splitting strength ratio, and fatigue resistance of the asphalt mixtures prepared in Examples 1-3 and Comparative Examples 1-2 were tested in accordance with JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering". The test results are shown in Table 1.

[0032] Table 1 As shown in Table 1, the asphalt mixture of the present invention exhibits good permeability coefficient, water stability, crack resistance, and fatigue resistance. The asphalt mixtures obtained in Examples 1-3 show superior performance compared to Comparative Examples 1 and 2. In Comparative Example 1, modified basalt fiber was replaced with basalt fiber modified with silane coupling agent and catechin in step (1) via physical mixing. In Comparative Example 2, pentaerythritol tetramethacrylate glycidyl ester was replaced with glycidyl methacrylate. Compared to Example 1, both showed poorer overall performance. Comparative Example 1 exhibited the worst performance, indicating that the modified basalt fiber of the present invention plays a crucial role in improving the performance of the asphalt mixture.

[0033] In summary, during the preparation of the asphalt mixture of this invention, after surface modification and grafting with catechin, basalt fibers enhance the compatibility of the fiber-asphalt interface through a three-dimensional network structure, significantly improving resistance to water damage, mechanical properties, and fatigue life, thereby delaying aging and extending the service life of the pavement.

[0034] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing high-performance basalt fiber asphalt mixture, characterized in that, Includes the following steps: (1) Basalt fiber was added to a mixed solution of ethanol and water, and then a silane coupling agent was added. After heating and reacting, silane coupling agent modified basalt fiber was obtained for later use. (2) Add catechin and pentaerythritol tetramethacrylate to a solvent, then add a catalyst, heat under nitrogen protection and reflux to react, collect the product and set aside; (3) Take the basalt fiber modified by silane coupling agent in step (1) and the product in step (2) respectively, add them to the solvent, add the coupling agent, and heat the reaction to obtain the modified basalt fiber. (4) The modified basalt fiber and aggregate are mixed and stirred to obtain a premix; (5) Add asphalt to the premix from step (4) and stir until homogeneous to obtain the final product.

2. The method for preparing a high-performance basalt fiber asphalt mixture according to claim 1, characterized in that, In step (1), the mass ratio of the basalt fiber, silane coupling agent, and mixed solution is 1:(0.3-0.5):(10-15); the silane coupling agent is KH-570, and the mixed solution is obtained by mixing ethanol and water in a volume ratio of 1:(2-3).

3. The method for preparing a high-performance basalt fiber asphalt mixture according to claim 1, characterized in that, In step (1), the heating reaction is carried out at a temperature of 50-60°C for 3-5 hours.

4. The method for preparing a high-performance basalt fiber asphalt mixture according to claim 1, characterized in that, In step (2), the mass ratio of catechin, pentaerythritol tetramethacrylate glycidyl ester, catalyst, and solvent is 1:(20-25):(55-60):(0.1-0.2).

5. The method for preparing a high-performance basalt fiber asphalt mixture according to claim 1, characterized in that, In step (2), the solvent is anhydrous ethanol, the catalyst is sodium hydroxide, and the reflux reaction time is 10-15 h.

6. The method for preparing a high-performance basalt fiber asphalt mixture according to claim 1, characterized in that, In step (3), the mass ratio of the basalt fiber modified with silane coupling agent in step (1), the product in step (2), the solvent, and the coupling agent is 60:(20-28):(1000-1300):(10-15); the coupling agent is vinyltriethoxysilane, and the solvent is N,N-dimethylformamide.

7. The method for preparing a high-performance basalt fiber asphalt mixture according to claim 1, characterized in that, In step (3), the heating reaction is carried out at a temperature of 55-60°C for 4-5 hours.

8. The method for preparing a high-performance basalt fiber asphalt mixture according to claim 1, characterized in that, In steps (4) and (5), the mass ratio of the asphalt, modified basalt fiber, and aggregate is 1:(0.05-0.1):(15-20).

9. The method for preparing a high-performance basalt fiber asphalt mixture according to claim 1, characterized in that, In step (5), the aggregate is divided into: a first aggregate with a particle size of 9-18 mm, a second aggregate with a particle size of 3-9 mm, and a third aggregate with a particle size of 0-3 mm; the mass ratio of the first aggregate, the second aggregate, and the third aggregate is 4:(5-6):(2-3); in step (5), the stirring temperature is 150-170℃.

10. A high-performance basalt fiber asphalt mixture, characterized in that, It is prepared by the preparation method according to any one of claims 1-9.

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