High-strength asphalt mixture and preparation method thereof

Abstract

The invention relates to the technical field of asphalt mixtures, and provides a high-strength asphalt mixture and a preparation method thereof.The asphalt mixture is prepared from, by weight, 50 parts of asphalt, 800-900 parts of basalt aggregate, 50-100 parts of limestone mineral powder and 5-10 parts of modified lignin fiber; the raw materials of the modified lignin fiber comprise a methyl methacrylate-styrene copolymer and lignin fiber in a weight ratio of (5-10): 95. According to the technical scheme, the problem that the strength and the rutting resistance of the asphalt mixture are poor due to poor dispersity of lignin fibers in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of asphalt mixtures, and in particular to a high-strength asphalt mixture and a preparation method thereof. Background Art

[0002] As the urbanization process continues to accelerate, road construction is developing rapidly. Asphalt mixture, as a widely used material in road construction, plays a vital role in meeting the growing traffic demand. In order to improve the performance of asphalt mixture, the industry generally adopts the practice of adding fibers, such as lignin fiber, mineral fiber and polyester fiber. Among them, lignin fiber has attracted widespread attention due to its excellent oil absorption performance and interfacial effect. However, the dispersion performance of lignin fiber in asphalt is poor, which makes the strength and anti-rutting performance of asphalt mixture with lignin fiber added low, thus limiting the application of lignin fiber in asphalt mixture. Summary of the invention

[0003] The present invention provides a high-strength asphalt mixture and a preparation method thereof, which solves the problem in the related art that the asphalt mixture has poor strength and anti-rutting performance due to poor dispersibility of lignin fibers.

[0004] The technical solution of the present invention is as follows: The present invention provides a high-strength asphalt mixture, the raw materials of which include the following components in parts by weight: 50 parts of asphalt, 800-900 parts of basalt aggregate, 50-100 parts of limestone powder, and 5-10 parts of modified lignin fiber; The raw materials of the modified lignin fiber include methyl methacrylate-styrene copolymer and lignin fiber in a weight ratio of 5 to 10:95.

[0005] As a further technical solution, the method for preparing the modified lignin fiber comprises the following steps: blending methyl methacrylate-styrene copolymer and lignin fiber, extruding, and granulating to obtain the modified lignin fiber.

[0006] As a further technical solution, during the extrusion, the temperature is 180-220°C.

[0007] As a further technical solution, the raw material of the modified lignin fiber also includes p-hydroxycinnamic acid.

[0008] In the present invention, the inventors found that when the raw material for modifying lignin fiber includes p-hydroxycinnamic acid, the strength and anti-rutting performance of asphalt mixture can be further improved. It is speculated that: the hydroxyl group and carboxyl group of p-hydroxycinnamic acid can form hydrogen bonds with the active groups on the surface of lignin fiber; its aromatic ring and carbon-carbon double bond can form weak interactions between aromatic rings with methyl methacrylate-styrene copolymer, which makes p-hydroxycinnamic acid play a "bridging" role, thereby further improving the modification effect of methyl methacrylate-styrene copolymer on lignin fiber, thereby further improving the strength and anti-rutting performance of asphalt mixture.

[0009] As a further technical solution, the weight ratio of the p-hydroxycinnamic acid to the lignin fiber is 1-3:95.

[0010] In the present invention, when the weight ratio of p-hydroxycinnamic acid to lignin fiber is 1-3:95, it helps to further improve the strength and anti-rutting performance of the asphalt mixture.

[0011] As a further technical solution, the asphalt includes one of rock asphalt, coal asphalt and petroleum asphalt, preferably petroleum asphalt.

[0012] As a further technical solution, the basalt aggregate includes basalt coarse aggregate and basalt fine aggregate in a mass ratio of 7 to 8:1; The particle size of the basalt coarse aggregate is 4.75-13.2 mm; The particle size of the basalt fine aggregate is 2.36-0.3 mm.

[0013] As a further technical solution, the particle size of the limestone powder is 75-150 μm.

[0014] In the present invention, through the gradation design of basalt aggregate and limestone powder, the particles inside the asphalt mixture can be embedded in each other to form a stable structure, thereby better resisting the external force.

[0015] The present invention also provides a method for preparing a high-strength asphalt mixture, comprising the following steps: mixing various components of the raw materials until they are uniform to obtain an asphalt mixture.

[0016] As a further technical solution, during the mixing, the temperature is 140-160°C.

[0017] The working principle and beneficial effects of the present invention are: In the present invention, the raw materials of the asphalt mixture include modified lignin fibers. The surface of the lignin fibers is modified by methyl methacrylate-styrene copolymer, which can improve the non-polarity of the lignin fiber surface, thereby improving the dispersion effect of the lignin fibers in the asphalt, making the "reinforcing bar" effect of the lignin fibers more prominent, thereby significantly improving the strength and rutting resistance of the asphalt mixture. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] In the following embodiments and comparative examples, unless otherwise specified, the asphalt is petroleum asphalt, model AH-90; the particle size of the basalt coarse aggregate is 9.5 mm; the particle size of the basalt fine aggregate is 2.36 mm; the particle size of the limestone powder is 100 μm; the model of methyl methacrylate-styrene copolymer is PM-600; and the lignin fiber is granular lignin fiber, model KLW-005, with a particle size of 5 mm.

[0020] Example 1 A method for preparing a high-strength asphalt mixture comprises the following steps: by weight, 50 parts of asphalt, 700 parts of basalt coarse aggregate, 100 parts of basalt fine aggregate, 50 parts of limestone powder, and 5 parts of modified lignin fiber are mixed at 140° C. until uniform, to obtain an asphalt mixture; The preparation method of the modified lignin fiber comprises the following steps: blending 5 parts of methyl methacrylate-styrene copolymer and 95 parts of lignin fiber, extruding, and granulating to obtain modified lignin fiber with a particle size of 5 mm; During extrusion, the temperature of zone 1 is 180°C, the temperature of zone 2 is 220°C, and the temperature of zone 3 is 200°C.

[0021] Example 2 A method for preparing a high-strength asphalt mixture comprises the following steps: by weight, 50 parts of asphalt, 800 parts of basalt coarse aggregate, 100 parts of basalt fine aggregate, 100 parts of limestone mineral powder, and 10 parts of modified lignin fiber are mixed at 160° C. until uniform, to obtain an asphalt mixture; The preparation method of the modified lignin fiber comprises the following steps: blending 10 parts of methyl methacrylate-styrene copolymer and 95 parts of lignin fiber, extruding, and granulating to obtain modified lignin fiber with a particle size of 5 mm; During extrusion, the temperature of zone 1 is 180°C, the temperature of zone 2 is 220°C, and the temperature of zone 3 is 200°C.

[0022] Example 3 A method for preparing a high-strength asphalt mixture comprises the following steps: by weight, 50 parts of asphalt, 800 parts of basalt coarse aggregate, 100 parts of basalt fine aggregate, 100 parts of limestone mineral powder, and 10 parts of modified lignin fiber are mixed at 160° C. until uniform, to obtain an asphalt mixture; The preparation method of the modified lignin fiber comprises the following steps: blending 10 parts of methyl methacrylate-styrene copolymer, 0.5 parts of salicylic acid and 95 parts of lignin fiber, extruding, and granulating to obtain modified lignin fiber with a particle size of 5 mm; During extrusion, the temperature of zone 1 is 180°C, the temperature of zone 2 is 220°C, and the temperature of zone 3 is 200°C.

[0023] Example 4 A method for preparing a high-strength asphalt mixture comprises the following steps: by weight, 50 parts of asphalt, 800 parts of basalt coarse aggregate, 100 parts of basalt fine aggregate, 100 parts of limestone mineral powder, and 10 parts of modified lignin fiber are mixed at 160° C. until uniform, to obtain an asphalt mixture; The preparation method of the modified lignin fiber comprises the following steps: blending 10 parts of methyl methacrylate-styrene copolymer, 0.5 parts of p-hydroxycinnamic acid and 95 parts of lignin fiber, extruding, and granulating to obtain modified lignin fiber with a particle size of 5 mm; During extrusion, the temperature of zone 1 is 180°C, the temperature of zone 2 is 220°C, and the temperature of zone 3 is 200°C.

[0024] Example 5 A method for preparing a high-strength asphalt mixture comprises the following steps: by weight, 50 parts of asphalt, 800 parts of basalt coarse aggregate, 100 parts of basalt fine aggregate, 100 parts of limestone mineral powder, and 10 parts of modified lignin fiber are mixed at 160° C. until uniform, to obtain an asphalt mixture; The preparation method of the modified lignin fiber comprises the following steps: blending 10 parts of methyl methacrylate-styrene copolymer, 5 parts of p-hydroxycinnamic acid and 95 parts of lignin fiber, extruding, and granulating to obtain modified lignin fiber with a particle size of 5 mm; During extrusion, the temperature of zone 1 is 180°C, the temperature of zone 2 is 220°C, and the temperature of zone 3 is 200°C.

[0025] Example 6 A method for preparing a high-strength asphalt mixture comprises the following steps: by weight, 50 parts of asphalt, 800 parts of basalt coarse aggregate, 100 parts of basalt fine aggregate, 100 parts of limestone mineral powder, and 10 parts of modified lignin fiber are mixed at 160° C. until uniform, to obtain an asphalt mixture; The preparation method of the modified lignin fiber comprises the following steps: blending 10 parts of methyl methacrylate-styrene copolymer, 1 part of p-hydroxycinnamic acid and 95 parts of lignin fiber, extruding, and granulating to obtain modified lignin fiber with a particle size of 5 mm; During extrusion, the temperature of zone 1 is 180°C, the temperature of zone 2 is 220°C, and the temperature of zone 3 is 200°C.

[0026] Example 7 A method for preparing a high-strength asphalt mixture comprises the following steps: by weight, 50 parts of asphalt, 800 parts of basalt coarse aggregate, 100 parts of basalt fine aggregate, 100 parts of limestone mineral powder, and 10 parts of modified lignin fiber are mixed at 160° C. until uniform, to obtain an asphalt mixture; The preparation method of the modified lignin fiber comprises the following steps: blending 10 parts of methyl methacrylate-styrene copolymer, 3 parts of p-hydroxycinnamic acid and 95 parts of lignin fiber, extruding, and granulating to obtain modified lignin fiber with a particle size of 5 mm; During extrusion, the temperature of zone 1 is 180°C, the temperature of zone 2 is 220°C, and the temperature of zone 3 is 200°C.

[0027] Comparative Example 1 A method for preparing a high-strength asphalt mixture comprises the following steps: by weight, 50 parts of asphalt, 700 parts of basalt coarse aggregate, 100 parts of basalt fine aggregate, 50 parts of limestone powder, and 5 parts of lignin fiber are mixed at 140° C. until uniform, to obtain an asphalt mixture.

[0028] Comparative Example 2 A method for preparing a high-strength asphalt mixture comprises the following steps: by weight, 50 parts of asphalt, 700 parts of basalt coarse aggregate, 100 parts of basalt fine aggregate, 50 parts of limestone powder, 0.25 parts of methyl methacrylate-styrene copolymer and 4.75 parts of lignin fiber are mixed at 140° C. until uniform, to obtain an asphalt mixture.

[0029] The asphalt mixtures prepared in Examples 1 to 7 and Comparative Examples 1 to 2 were subjected to the following performance tests: ① Compression strength: The compressive strength was tested by uniaxial compression test according to JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering". The sample size was φ100mm×100mm, and the average value of 3 samples was taken as the final result. ② Anti-rutting performance: Refer to JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" to test dynamic stability, where the sample size is 300mm×300mm×50mm and the test temperature is 60℃.

[0030] The test results are shown in Table 1 below.

[0031] Table 1 Asphalt mixture performance test results

[0032] Comparison between Example 1 and Comparative Examples 1-2 shows that surface modification of lignin fibers by methyl methacrylate-styrene copolymer can significantly improve the strength and rutting resistance of asphalt mixtures.

[0033] Comparison between Example 2 and Example 4 shows that when the raw material of the modified lignin fiber includes p-hydroxycinnamic acid, the strength and anti-rutting performance of the asphalt mixture can be further improved.

[0034] Comparison between Example 3 and Example 4 shows that, when preparing modified lignin fibers, adding p-hydroxycinnamic acid can further improve the strength and rutting resistance of asphalt mixtures compared to adding salicylic acid.

[0035] Comparison between Examples 4-5 and Examples 6-7 shows that when the weight ratio of p-hydroxycinnamic acid to lignin fiber is 1-3:95, it helps to further improve the strength and anti-rutting performance of the asphalt mixture.

[0036] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-strength asphalt mixture, characterized in that: The raw materials include the following components in parts by weight: 50 parts of asphalt, 800-900 parts of basalt aggregate, 50-100 parts of limestone powder, and 5-10 parts of modified lignin fiber; The raw materials of the modified lignin fiber include methyl methacrylate-styrene copolymer and lignin fiber in a weight ratio of 5 to 10:

95.

2. A high-strength asphalt mixture according to claim 1, characterized in that: The preparation method of the modified lignin fiber comprises the following steps: blending methyl methacrylate-styrene copolymer and lignin fiber, extruding, and granulating to obtain the modified lignin fiber.

3. A high-strength asphalt mixture according to claim 2, characterized in that: During the extrusion, the temperature is 180-220°C.

4. The high-strength asphalt mixture according to claim 1, characterized in that: The raw material of the modified lignin fiber also includes p-hydroxycinnamic acid.

5. A high-strength asphalt mixture according to claim 4, characterized in that: The weight ratio of the p-hydroxycinnamic acid to the lignin fiber is 1-3:

95.

6. A high-strength asphalt mixture according to any one of claims 1 to 5, characterized in that: The asphalt includes one of rock asphalt, coal asphalt and petroleum asphalt.

7. A high-strength asphalt mixture according to any one of claims 1 to 5, characterized in that: The basalt aggregate includes basalt coarse aggregate and basalt fine aggregate in a mass ratio of 7 to 8:1; The particle size of the basalt coarse aggregate is 4.75-13.2 mm; The particle size of the basalt fine aggregate is 2.36-0.3 mm.

8. A high-strength asphalt mixture according to any one of claims 1 to 5, characterized in that: The particle size of the limestone powder is 75-150 μm.

9. The method for preparing a high-strength asphalt mixture according to any one of claims 1 to 8, characterized in that: The following steps are involved: The various components of the raw materials are mixed until uniform to obtain an asphalt mixture.

10. The method for preparing a high-strength asphalt mixture according to claim 9, characterized in that: During the mixing, the temperature is 140-160°C.

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