Emission reduction type waste polypropylene-based asphalt modifier as well as preparation method and application thereof

Abstract

The invention relates to an emission reduction type waste polypropylene-based asphalt modifier, which is prepared from the following components in parts by mass: 100 parts of recycled polypropylene and 0.01 to 3 parts of peroxide degradation agent, according to the asphalt modifier disclosed by the invention, after the recycled polypropylene is subjected to melting chemical degradation by adopting the peroxide degradation agent through a thermo-mechanochemical method, the melting temperature of the waste recycled polypropylene can be effectively reduced, and the mixing temperature of the recycled polypropylene can be reduced to 150-160 DEG C, so that the technical problem that the preparation temperature of modified asphalt and a mixture is too high is solved; the release of toxic and harmful gases is reduced, the purposes of energy conservation and emission reduction in the production process can be achieved, and a double-effect mode of promoting the recycling of waste polypropylene and improving the performance of the asphalt pavement is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of road construction materials, and in particular to an emission-reducing waste polypropylene-based asphalt modifier and a preparation method and application thereof. Background Art

[0002] Asphalt pavement has the advantages of comfortable driving, low noise, and wear resistance, and is widely used in highway construction at all levels. With the continuous increase in road traffic volume, the large-scale vehicles and the occurrence of serious overloading, ordinary asphalt pavement is prone to rutting, potholes, cracks, peeling and other diseases, resulting in a sharp decline in pavement performance and a serious shortening of service life. In order to make up for some of the shortcomings of the base asphalt pavement in road performance, existing studies have shown that the use of polymer modified asphalt is a more appropriate method.

[0003] Polypropylene (PP) is one of the commonly used thermoplastic polymers in daily life, and its products include disposable bowls, basins, car bumpers, etc. Its waste is usually landfilled or piled up, which will waste resources and pollute the ecological environment.

[0004] So far, the most common method of using waste PP plastics for asphalt modification is to first crush them into particles through simple mechanical treatment, and then add them to asphalt for further mixing at a temperature 20°C higher than the normal asphalt mixing temperature. This modification method usually requires high temperature (close to 200°C) for about 3 hours to achieve uniform mixing of PP and asphalt. However, excessively high mixing temperatures will lead to huge energy consumption and obvious emissions during the mixing process. Summary of the invention

[0005] The present application provides an emission-reducing waste polypropylene-based asphalt modifier and a preparation method thereof, which solves or partially solves the environmental problem caused by asphalt smoke emissions caused by excessively high mixing temperatures during the preparation of existing waste PP modified asphalt, and cannot guarantee the uniformity of the overall performance of the modified asphalt.

[0006] The present application provides an emission-reducing waste polypropylene-based asphalt modifier, comprising the following components: 100 parts of recycled polypropylene and 0.01 to 3 parts of a peroxide degradation agent, calculated by mass.

[0007] Preferably, the recycled polypropylene is obtained by sorting, cleaning, drying and crushing disposable tableware and / or plastic basins.

[0008] Preferably, the peroxide degradation agent includes, but is not limited to, benzoyl peroxide (BPO), dicumyl peroxide (DCP), di-tert-butyl peroxide (DTBP) and di-tert-butylperoxyisopropylbenzene (BIPB).

[0009] Based on the same inventive concept, the present application also provides a method for preparing an emission-reducing waste polypropylene-based asphalt modifier, which is used to prepare the emission-reducing waste polypropylene-based asphalt modifier, comprising the following steps:

[0010] By a thermomechanical chemical method, the peroxide degradation agent is added into the melt of the recycled polypropylene, mixed and stirred to obtain a degradation product;

[0011] The degradation product is cooled and then crushed and granulated to obtain the emission-reducing waste polypropylene-based asphalt modifier.

[0012] Preferably, during the mixing process of the peroxide degradation agent and the recycled polypropylene, the temperature is controlled at 180-200°C, the rotation speed is controlled at 40-60rpm, and the time is controlled at 5-10min;

[0013] During the crushing and granulation process of the degradation products, mechanical crushing at room temperature is adopted, and the particle size of the emission-reducing waste polypropylene-based asphalt modifier is ≤0.3 mm.

[0014] Based on the same inventive concept, the present application also provides a modified asphalt, comprising the following components: 1 to 10 parts of the emission-reducing waste polypropylene-based asphalt modifier and 100 parts of base asphalt, calculated by mass.

[0015] Preferably, the modified asphalt comprises the following components: 3 to 7 parts of the emission-reducing waste polypropylene-based asphalt modifier and 100 parts of base asphalt, calculated by mass.

[0016] Based on the same inventive concept, the present application also provides a method for preparing modified asphalt, which is used to prepare the modified asphalt, by mixing and stirring the emission-reducing waste polypropylene-based asphalt modifier with the base asphalt to obtain the modified asphalt.

[0017] Preferably, during the mixing and stirring process, the stirring temperature is 140-160° C., the shear rate is 2500-4000 rpm, and the shear time is 30-60 min.

[0018] Based on the same inventive concept, the present application also provides a modified asphalt mixture, comprising the following components: in parts by mass, 1 to 10 parts of the modified asphalt, and 100 parts of aggregate and mineral powder in total.

[0019] Preferably, the modified asphalt mixture comprises the following components: in parts by mass, 4 to 6 parts of the modified asphalt, and 100 parts of aggregate and mineral powder in total.

[0020] Based on the same inventive concept, the present application also provides a method for preparing a modified asphalt mixture, which is used to prepare the modified asphalt mixture, comprising the following steps:

[0021] Preheating the modified asphalt, the aggregate and the mineral powder respectively;

[0022] The modified asphalt mixture is obtained by mixing and stirring the preheated modified asphalt with the aggregate and the mineral powder;

[0023] Wherein, during the mixing and stirring process of the modified asphalt, the aggregate and the mineral powder, the temperature is controlled at 150-160°C.

[0024] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0025] The emission-reducing waste polypropylene-based asphalt modifier of the present application can effectively reduce the melting temperature of waste recycled polypropylene after melt chemical degradation of recycled polypropylene by a thermomechanical chemical method using a peroxide degradation agent, so that its mixing temperature can be reduced to 150-160°C, thereby solving the technical problem of too high preparation temperature of modified asphalt and mixture, reducing the release of toxic and harmful gases, and achieving the goal of energy conservation and emission reduction in the production process. When the degraded waste recycled polypropylene is used as a modifier for asphalt modification, the softening point and viscosity of asphalt can be increased, the needle penetration can be reduced, and the water stability and high-temperature permanent deformation resistance of asphalt mixture can be significantly improved, which has a high-quality improvement effect on the road performance of asphalt mixture, and prolongs its service life, saving engineering investment. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application are clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0027] The first aspect of the present invention provides a method for preparing an emission-reducing waste polypropylene-based asphalt modifier, the method comprising the following steps:

[0028] (1) adding a peroxide degradation agent to a recycled polypropylene melt and mixing the mixture to obtain a degradation product by a thermomechanical chemical method;

[0029] (2) The degradation products are cooled and then crushed and granulated to obtain an emission-reducing waste polypropylene-based asphalt modifier.

[0030] In the present method, the mass ratio of the amount of recovered PP to the amount of peroxide is 100:(0.01-3), specifically, for example, it can be 100:0.1, 100:0.5, 100:1, 100:1.5, 100:2, 100:2.5 or 100:3.

[0031] In the present method, in step (1), the mixing conditions include: a temperature of 180-200°C, specifically, for example, 180°C, 185°C, 190°C, 195°C or 200°C, a rotation speed of 40-60rpm, specifically, for example, 40rpm, 45rpm, 50rpm, 55rpm or 60rpm, and a time of 5-10min, specifically, for example, 5min, 6min, 7min, 8min, 9min or 10min.

[0032] In the present method, in step (1), the source of the recycled PP is not limited. Specifically, the recycled PP can be obtained by sorting, cleaning, drying and crushing disposable tableware and plastic basins.

[0033] In the present method, in step (1), the peroxide degradation agent includes but is not limited to benzoyl peroxide (BPO), dicumyl peroxide (DCP), di-tert-butyl peroxide (DTBP) and di-tert-butyl peroxyisopropylbenzene (BIPB).

[0034] In the present method, in step (2), the crushing is mechanical crushing at room temperature, and specifically, the mechanical crushing at room temperature is carried out in a room temperature crusher. In step (2), the particle size of the degradation product is ≤ 0.3 mm.

[0035] The second aspect of the present invention provides an emission-reducing waste polypropylene-based asphalt modifier prepared by the above method.

[0036] The third aspect of the present invention provides a method for preparing modified asphalt, wherein the above-mentioned emission-reducing waste polypropylene-based asphalt modifier is mixed with base asphalt. In this article, base asphalt refers to base asphalt in a molten state.

[0037] In the preparation method of modified asphalt of the present invention, in a specific embodiment, when the above-mentioned emission-reducing waste polypropylene-based asphalt modifier and the base asphalt are mixed, the mass ratio of the amount of the emission-reducing waste polypropylene-based asphalt modifier to the base asphalt is (1-10):100, specifically, for example, it can be 1:100, 2:100, 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 9:100 or 10:100. In a preferred embodiment, the mass ratio of the amount of the emission-reducing waste polypropylene-based asphalt modifier to the base asphalt is (3-7):100.

[0038] In the preparation method of the modified asphalt of the present invention, the mixing method is mechanical blending to ensure that the emission-reducing waste polypropylene-based asphalt modifier is fully swollen or dispersed in the matrix asphalt. In a preferred embodiment, the step of mechanical blending is: high-speed stirring by a high-speed shearing device, the stirring temperature is 140-160°C, for example, 140°C, 145°C, 150°C, 155°C or 160°C, the shear rate is 2500-4000rpm, for example, 2500rpm, 3000rpm, 3500rpm or 4000rpm, and the shear time is 30-60min, for example, 30min, 40min, 50min or 60min.

[0039] The fourth aspect of the present invention provides a modified asphalt prepared by the above method.

[0040] The fifth aspect of the present invention provides a method for preparing a modified asphalt mixture, wherein the modified asphalt, aggregate and mineral powder are preheated separately, and then the preheated modified asphalt, aggregate and mineral powder are mixed.

[0041] In the method for preparing the modified asphalt mixture of the present invention, the aggregate can be selected conventionally in the art.

[0042] In the method for preparing the modified asphalt mixture of the present invention, the mineral powder can be a conventional choice in the art.

[0043] In the preparation method of the modified asphalt mixture of the present invention, in a preferred embodiment, the ratio of the weight of the modified asphalt to the total weight of the aggregate and the mineral powder is (1-10):100, specifically, for example, 2:100, 3:100, 4:100, 4.5:100, 5:100, 5.5:100, 6:100, 7:100, 8:100, 9:100. In a preferred embodiment, the mass ratio of the amount of the emission-reducing waste polypropylene-based asphalt modifier to the base asphalt is (4-6):100.

[0044] In the preparation method of the modified asphalt mixture of the present invention, in a specific embodiment, the preheating temperature of the aggregate and the mineral powder is 170-190°C, and the preheating time is 4-8h; the modified asphalt is preheated to a molten state at a temperature of 140-160°C.

[0045] In the preparation method of the modified asphalt mixture of the present invention, in the specific operation process, the preheated modified asphalt and mineral powder are sequentially added to the preheated aggregate for mixing, and the specific steps are as follows:

[0046] (1) Mix the preheated aggregate at 150°C for 60 seconds;

[0047] (2) Add the molten modified asphalt into the aggregate and continue mixing for 60 seconds;

[0048] (3) The preheated mineral powder is added to the mixture of modified asphalt and aggregate and mixed for 60 seconds to obtain a modified asphalt mixture.

[0049] The sixth aspect of the present invention provides a modified asphalt mixture prepared by the above method.

[0050] The following examples further illustrate the emission-reducing waste polypropylene-based asphalt modifier and its preparation method of the present invention. The examples are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following examples.

[0051] The experimental methods in the following examples, unless otherwise specified, are all conventional methods in the art. The experimental materials used in the following examples, unless otherwise specified, are all commercially available.

[0052] Example 1

[0053] The PP in this embodiment is obtained by sorting, cleaning, drying and crushing recycled disposable tableware and plastic basins.

[0054] Preparation of emission-reducing waste polypropylene-based asphalt modifier:

[0055] (1) by a thermomechanical chemical method, 0.5 g of benzoyl peroxide (BPO) was added to 100 g of recycled polypropylene melt at a temperature of 180° C. and a rotation speed of 40 rpm and mixed for 5 min to obtain a degradation product;

[0056] (2) The degradation products are cooled and then crushed and granulated to obtain an emission-reducing waste polypropylene-based asphalt modifier.

[0057] (II) Application of emission-reducing waste polypropylene-based asphalt modifier:

[0058] Preparation of modified asphalt: 80 g of the emission-reducing waste polypropylene-based asphalt modifier prepared in Example 1 was added to 2000 g of molten matrix asphalt, and high-speed stirring was performed at 150° C. using a high-speed shearing device. The stirring temperature was 150° C., the shear rate was 4000 rpm, and the shear time was 60 min to prepare modified asphalt;

[0059] Preparation of modified asphalt mixture: Use AC type dense mix commonly used in highway pavement, weigh 20kg of aggregates of corresponding particle size and mineral powder, and preheat them in an oven at 180℃ for 4h. Preheat the modified asphalt prepared in Example 1 to a molten state at 150℃, then add the preheated aggregates to a mixing pot at 150℃ and mix for 60s, then add 0.96kg of molten modified asphalt to the mixing pot and continue mixing for 60s. Finally, add mineral powder and continue mixing. After 90s, stop the machine and unload the materials to prepare the modified asphalt mixture.

[0060] Example 2

[0061] The method of Example 1 is followed, except that when preparing the low-emission waste polypropylene-based asphalt modifier, the amount of BPO used is 1 g.

[0062] Example 3

[0063] The method of Example 1 is followed, except that when preparing the low-emission waste polypropylene-based asphalt modifier, the amount of BPO used is 1.5 g.

[0064] Example 4

[0065] The method of Example 1 is followed, except that when preparing the low-emission waste polypropylene-based asphalt modifier, the amount of BPO used is 2 g.

[0066] Example 5

[0067] The method of Example 1 is followed, except that when preparing the low-emission waste polypropylene-based asphalt modifier, the amount of BPO used is 2.5 g.

[0068] Example 6

[0069] The method of Example 1 is followed, except that when preparing the low-emission waste polypropylene-based asphalt modifier, the amount of BPO used is 3 g.

[0070] Comparative Example 1

[0071] The method of Example 1 is followed, except that the modifier used is recycled PP that has not been subjected to BPO degradation treatment, the stirring temperature of the modified asphalt during high-speed shearing is 190°C, and the mixing temperature of the modified asphalt and aggregate is 190°C.

[0072] Test Case

[0073] Softening point: According to the T0606 specification of "Testing Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011), the modified asphalt in the examples and comparative examples was tested for softening point using the ring and ball method. Specific testing process: (1) Place the sample ring containing the asphalt sample together with the sample base plate in a constant temperature water tank filled with 5℃±0.5℃ water for at least 15 minutes; (2) Pour freshly boiled water cooled to 5℃ into the beaker, with the water surface slightly lower than the depth mark on the vertical pole; (3) Take out the sample ring containing the asphalt sample from the constant temperature water tank and place it in the circular hole of the middle plate of the bracket, put on the positioning ring and put it into the beaker, and keep the water temperature at 5℃±0.5℃. (4) Place the steel ball in the center of the sample in the middle of the positioning ring, immediately start the electromagnetic oscillator to make the water oscillate slightly, and start heating. Adjust the water temperature in the cup to maintain a rise of 5°C ± 0.5°C per minute within 3 minutes. (5) The asphalt sample softens due to the heat and gradually falls. When it contacts the surface of the lower bottom plate, read the temperature immediately.

[0074] Ductility: According to the test method of "Testing Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011 T0605), the modified asphalt in the embodiment and the comparative example was tested for ductility at a test temperature of 10°C and a tensile speed of 5cm / min±0.25cm / min. Specific test process: (1) Prepare the ductility test specimen and place it in a ductility tester water tank at a water temperature of 10°C for at least 1.5 hours; (2) Place the specimen in the test area, remove the side mold and fix the mold end; (3) Start the test for constant temperature stretching, keep the equipment stable, and record the tensile length at break, in cm;

[0075] Viscosity: According to the test method of "Testing Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011 T0625), the viscosity of the modified asphalt in the embodiment and the comparative example was tested at a test temperature of 135°C. Specific test process: (1) Place the asphalt sample in a viscosity test sample cylinder and keep it warm for 1.5 hours; (2) Insert the selected rotor into the asphalt liquid level in the sample cylinder to a specified height and continue to keep it warm for more than 15 minutes; (3) Start the viscosity test, observe the change in viscosity value, read and record after it stabilizes, and determine the average value of 3 readings;

[0076] Marshall residual stability after immersion: According to the test method of "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011 T 0702), the Marshall specimens of the modified asphalt mixtures of the embodiments and comparative examples were prepared by compaction method. According to the test method of "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011 T 0709), the Marshall stability tester was used to carry out Marshall stability test on the above-mentioned asphalt mixture specimens. The difference between the immersion Marshall test and the above-mentioned test is that the specimens need to be kept warm in a constant temperature water tank at 60°C for 48 hours. Furthermore, the percentage of the ratio of the Marshall stability after immersion to the Marshall stability before immersion is taken as the water-immersion Marshall residual stability, which is used to evaluate the water stability of the above-mentioned asphalt mixture. The larger the value, the better the water stability;

[0077] Dynamic stability: According to the test method of "Testing Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011T 0719), the high temperature stability of the asphalt mixture rutting specimens prepared in the examples and comparative examples was tested by rutting test. The specific test steps are as follows: (1) The rutting specimens with a size of 300mm×300mm×50mm are formed by rolling method, and then the formed specimens and the test molds are placed at room temperature for no less than 48 hours to fully solidify; (2) The solidified specimens are placed in a rutting test machine at 60°C for 5 hours, and the ground pressure is adjusted to 0.7±0.05MPa; (3) After the insulation time is over, the rutting tester is turned on for testing. The high temperature stability of the above-mentioned asphalt mixture is evaluated by the dynamic stability (DS) index. The larger the value, the better the ability of the specimen to resist high temperature and rutting deformation.

[0078] Maximum bending-tensile strain: According to the test method of "Test Procedure for Asphalt and Asphalt Mixture in Highway Engineering" (JTG E20-2011 T0715), the asphalt mixture specimens prepared in the embodiments and comparative examples were tested at a low temperature of -10°C with a loading rate of 50 mm / min. The low-temperature performance of the specimens was evaluated by the maximum bending-tensile strain when the specimens were destroyed.

[0079] The softening point, needle penetration and viscosity of the modified asphalt and base asphalt prepared in Examples 1-6 and Comparative Example 1 were measured respectively. The results are shown in Table 1.

[0080] Table 1

[0081]

[0082] As can be seen from Table 1, the emission-reducing waste polypropylene-based asphalt modifier prepared by the present invention is used to prepare modified asphalt. In terms of softening temperature, the softening point of the prepared modified asphalt is slightly reduced, but it can still improve the high-temperature performance of the base asphalt well; in terms of ductility, BPO can significantly compensate for the negative effect of waste recycled PP on the ductility of asphalt; in terms of viscosity, BPO will significantly improve the working performance of modified asphalt.

[0083] The submerged Marshall residual stability, dynamic stability and maximum flexural strain of the modified asphalt mixtures prepared in Examples 1-6 and Comparative Example 1, as well as the base asphalt mixture and the standard requirements for the working performance and road performance of the modified asphalt mixture in the field were measured respectively. The results are shown in Table 2.

[0084] Table 2

[0085]

[0086] According to the data in Table 2, it can be seen that the asphalt modifier prepared by the thermomechanical chemical method using BPO chemical degradation is used to prepare modified asphalt, and the modified asphalt is used to prepare modified asphalt mixture. When the water stability is evaluated by measuring the residual Marshall stability of immersion, the road use standard requirements of the mixture are met (≥80%); at the same time, in terms of high temperature performance of the pavement (dynamic stability), the modifier has a significant improvement effect on the high temperature performance of the base asphalt mixture; in terms of low temperature performance of the pavement, the maximum bending tensile strain meets the standard requirements of modified asphalt (≥2000με). In general, the asphalt modifier prepared by the present invention has a good modification effect on the asphalt mixture, and can make the prepared asphalt mixture meet the road performance standards of the modified asphalt mixture, especially outstanding in terms of water stability and high temperature resistance to permanent deformation.

[0087] In summary, the emission-reducing waste polypropylene-based asphalt modifier prepared by the present invention is used to prepare modified asphalt or modified asphalt mixture, and is used to build roads. While having good working performance and road performance, energy conservation and emission reduction in the production process can be achieved. At the same time, the present invention can realize the resource utilization of waste polypropylene, and has significant environmental, social and economic benefits.

[0088] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is 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 waste polypropylene-based asphalt modifier for emission reduction, characterized in that: The invention comprises the following components: by weight, 100 parts of recycled polypropylene and 0.01 to 3 parts of a peroxide degradation agent.

2. The emission-reducing waste polypropylene-based asphalt modifier according to claim 1, characterized in that: The recycled polypropylene is obtained by classifying, cleaning, drying and crushing disposable tableware and / or plastic basins.

3. The emission-reducing waste polypropylene-based asphalt modifier according to claim 1, characterized in that: The peroxide degradation agent includes, but is not limited to, benzoyl peroxide (BPO), dicumyl peroxide (DCP), di-tert-butyl peroxide (DTBP) and di-tert-butylperoxyisopropylbenzene (BIPB).

4. A method for preparing an emission-reducing waste polypropylene-based asphalt modifier, characterized in that: The method for preparing the emission-reducing waste polypropylene-based asphalt modifier according to any one of claims 1 to 3 comprises the following steps: By a thermomechanical chemical method, the peroxide degradation agent is added to the melt of the recycled polypropylene, mixed and stirred to obtain a degradation product; The degradation product is cooled and then crushed and granulated to obtain the emission-reducing waste polypropylene-based asphalt modifier.

5. The method for preparing the emission-reducing waste polypropylene-based asphalt modifier according to claim 4, characterized in that: During the mixing process of the peroxide degradation agent and the recycled polypropylene, the temperature is controlled at 180-200° C., the rotation speed is controlled at 40-60 rpm, and the time is controlled at 5-10 min; During the crushing and granulation process of the degradation products, mechanical crushing at room temperature is adopted, and the particle size of the emission-reducing waste polypropylene-based asphalt modifier is ≤0.3 mm.

6. A modified asphalt, characterized in that: The invention comprises the following components: by weight, 1 to 10 parts of the emission-reducing waste polypropylene-based asphalt modifier described in any one of claims 1 to 3 and 100 parts of base asphalt.

7. A method for preparing modified asphalt, characterized in that: For preparing the modified asphalt described in claim 6, the modified asphalt is obtained by mixing the emission-reducing waste polypropylene-based asphalt modifier with the base asphalt and stirring them evenly.

8. The method for preparing modified asphalt according to claim 7, characterized in that: During the mixing and stirring process, the stirring temperature is 140-160° C., the shear rate is 2500-4000 rpm, and the shear time is 30-60 min.

9. A modified asphalt mixture, characterized in that: The invention comprises the following components: by weight, 1 to 10 parts of the modified asphalt described in claim 6, and 100 parts of aggregate and mineral powder in total.

10. A method for preparing a modified asphalt mixture, characterized in that: The method for preparing the modified asphalt mixture according to claim 9 comprises the following steps: Preheating the modified asphalt, the aggregate and the mineral powder respectively; The modified asphalt mixture is obtained by mixing and stirring the preheated modified asphalt with the aggregate and the mineral powder; The modified asphalt is preheated to a molten state at a temperature of 140-160°C; the preheating temperature of the aggregate and mineral powder is 170-190°C, and the preheating time is 4-8h; during the mixing and stirring process of the modified asphalt, the aggregate and mineral powder, the temperature is controlled at 150-160°C.

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