Low temperature resistant matrix asphalt mixture and method for preparing the same

Abstract

The application relates to the technical field of asphalt mixtures, and particularly discloses a low-temperature-resistant matrix asphalt mixture and a preparation method thereof.The matrix asphalt mixture comprises the following components in parts by weight: 74-82 parts of broken stones, 13-15 parts of machine-made sand, 10-12 parts of solid waste-based mineral powder, 5.9-7.9 parts of matrix asphalt and 0.3-2 parts of lignin fibers.The application uses matrix asphalt as a binding material, and processes sodium lignosulfonate and solid waste powder into solid waste-based mineral powder through wet ball milling, so that the matrix asphalt and the mineral powder have good binding force, and the cohesion of the matrix asphalt is strengthened, and therefore the asphalt mixture can have good low-temperature resistance after being formed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of asphalt mixture, in particular to a low-temperature-resistant base asphalt mixture and a preparation method thereof. BACKGROUND

[0002] Asphalt mixture is a composite material mainly composed of asphalt, coarse aggregate, fine aggregate and mineral powder, and the performance can be improved by adding polymer, lignin fiber and other components.

[0003] In the related art, there is an asphalt mixture including the following components in parts by weight: 74 parts of crushed stone, 13 parts of fine aggregate, 10 parts of mineral powder, 5.9 parts of SBS modified asphalt and 0.3 parts of lignin fiber. The crushed stone is basalt crushed stone, the fine aggregate is machine-made sand, and the mineral powder is limestone mineral powder.

[0004] In view of the above related art, the inventors believe that the price of SBS modified asphalt is usually higher than that of base asphalt, so the asphalt mixture in the related art has a high production cost. However, if the SBS modified asphalt in the related art is replaced by base asphalt for the purpose of cost saving, it is difficult to make the asphalt mixture have good low-temperature resistance. SUMMARY

[0005] In the related art, if the SBS modified asphalt is replaced by base asphalt to reduce the cost, it is difficult to make the asphalt mixture have good low-temperature resistance. In order to improve this defect, the present application provides a low-temperature-resistant base asphalt mixture and a preparation method thereof.

[0006] In the first aspect, the present application provides a low-temperature-resistant base asphalt mixture, which adopts the following technical scheme:

[0007] A low-temperature-resistant base asphalt mixture, the base asphalt mixture includes the following components in parts by weight: 74-82 parts of crushed stone, 13-15 parts of machine-made sand, 10-12 parts of solid waste-based mineral powder, 5.9-7.9 parts of base asphalt and 0.3-2 parts of lignin fiber, the solid waste-based mineral powder is obtained by wet ball milling and drying of a solid waste mixture, and the components of the solid waste mixture include solid waste powder and sodium lignosulfonate compounded at a weight ratio of (40-80):1, and the solid waste powder includes red mud powder.

[0008] By adopting the technical scheme, the asphalt mixture takes base asphalt as a binder, and the sodium lignosulfonate and the solid waste powder are processed into the solid waste-based mineral powder through wet ball milling. The red mud powder and the sodium lignosulfonate can be obtained from industrial waste, and the cost is low. Moreover, the sodium lignosulfonate can be adsorbed on the surface of the red mud powder through electrostatic action. Since the base asphalt contains a certain amount of aromatic compounds, and the sodium lignosulfonate also contains a large amount of aryl groups, the sodium lignosulfonate on the surface of the solid waste-based mineral powder can make the solid waste-based mineral powder and the base asphalt have good compatibility and strong binding force. At the same time, the lignin groups in the sodium lignosulfonate can adsorb part of the free asphalt in the base asphalt, which helps to improve the cohesion of the base asphalt. Since the binding force between the base asphalt and the solid waste-based mineral powder is good, and the cohesion of the base asphalt is strengthened, the asphalt mixture can have good low-temperature resistance after being formed, which helps to overcome the defect of poor low-temperature resistance of the asphalt mixture at the premise of saving cost.

[0009] Preferably, the solid waste-based mineral powder is prepared by the following method:

[0010] (1) mixing the solid waste powder and the sodium lignosulfonate to obtain a solid waste mixture;

[0011] (2) mixing the solid waste mixture and water to obtain a solid waste slurry, adding the solid waste slurry into a wet ball milling device for ball milling, and dehydrating the solid waste slurry after the ball milling to obtain the solid waste-based mineral powder.

[0012] By adopting the technical scheme, the solid waste powder and the sodium lignosulfonate are prepared into the solid waste mixture. After the solid waste mixture is mixed with water, the sodium lignosulfonate is dissolved, and is fully contacted with the solid waste powder and is adsorbed in the wet grinding process. Finally, the solid waste-based mineral powder is obtained through dehydration treatment.

[0013] Preferably, the average particle size of the red mud powder is 30-60 μm.

[0014] By adopting the technical scheme, the average particle size of the red mud powder is preferred, which helps to improve the bonding effect between the base asphalt and the solid waste-based mineral powder, thereby enhancing the low-temperature resistance of the asphalt mixture after being formed.

[0015] Preferably, the red mud powder is a Bayer process red mud powder, and the solid waste powder further includes a waste concrete micro-powder. The waste concrete micro-powder is prepared by crushing the waste concrete, screening out the coarse aggregate, grinding the remaining material, screening out the fine aggregate, and continuously grinding the remaining material to obtain the waste concrete micro-powder.

[0016] By adopting the technical scheme, the waste concrete micro powder is used as the solid waste powder in addition to the Bayer process red mud powder. After the waste concrete is subjected to primary screening, the coarse aggregate is screened out, and the remaining dry mortar particles with relatively small particle size are obtained. After the dry mortar particles are ground, the cement stone and fine aggregate are separated, and then the cement stone is screened out and further ground to obtain the waste concrete micro powder.

[0017] The waste concrete micro powder has a certain alkalinity and a higher calcium content than the Bayer process red mud powder, and has a good adsorption effect on sodium lignosulfonate. When used in an appropriate amount, the waste concrete micro powder can enhance the carrying capacity of the solid waste base mineral powder for sodium lignosulfonate, and help to improve the low-temperature resistance of the asphalt mixture after molding.

[0018] Preferably, the average particle size of the waste concrete micro powder is 14-18 pm.

[0019] By adopting the technical scheme, the average particle size of the waste concrete micro powder is optimized, which helps to improve the low-temperature resistance of the asphalt mixture after molding.

[0020] Preferably, the solid waste powder and sodium lignosulfonate in the solid waste mixture are compounded in a weight ratio of (40-60):1.

[0021] By adopting the technical scheme, the ratio of the solid waste mixture is optimized, which helps to improve the low-temperature resistance of the asphalt mixture after molding.

[0022] Preferably, the solid waste powder is mixed by mixing the red mud powder and the waste concrete micro powder in a weight ratio of (3.2-4.4):1.

[0023] By adopting the technical scheme, the weight ratio of the red mud powder and the waste concrete micro powder is optimized, which helps to improve the low-temperature resistance of the asphalt mixture after molding.

[0024] In a second aspect, the application provides a preparation method of a low-temperature-resistant base asphalt mixture, which adopts the following technical scheme.

[0025] A preparation method of a low-temperature-resistant base asphalt mixture, comprising the following steps:

[0026] (1) mixing the crushed stone, the machine-made sand and the solid waste base mineral powder to obtain dry mixed material, and preheating the dry mixed material at 180-190 DEG C for standby;

[0027] (2) adding the base asphalt preheated to 170-180 DEG C into the dry mixed material, mixing, stirring at 180-190 DEG C for 10-20 min to obtain a mixture base, adding lignin fiber into the mixture base and continuing to heat and stir for 20-30 min to obtain a base asphalt mixture.

[0028] By adopting the technical scheme, the dry mixing material is prepared first, then the matrix asphalt is mixed with the dry mixing material to obtain a mixture matrix, and then the lignin fiber is added for continued heat preservation and stirring, so that the low-temperature-resistant matrix asphalt mixture is obtained.

[0029] As preferred, in the step (2) of preparing the asphalt mixture, the PET fiber and the lignin fiber are jointly added into the mixture matrix.

[0030] By adopting the technical scheme, the PET fiber contains a large number of benzene rings, and the lignin fiber and the matrix asphalt also contain a certain amount of benzene rings, so that the PET fiber has good compatibility with the lignin fiber and the matrix asphalt. The PET fiber can synergistically adsorb the free asphalt with the lignin fiber, improve the stability of the free asphalt, and also can jointly produce a toughening effect in the asphalt mixture, which helps to improve the low-temperature resistance of the asphalt mixture after forming.

[0031] As preferred, the added amount of the PET fiber is 1.2-1.6% of the weight of the matrix asphalt.

[0032] By adopting the technical scheme, the added amount of the PET fiber is preferred, which helps to improve the low-temperature resistance of the asphalt mixture after forming.

[0033] In summary, the present application has the following beneficial effects:

[0034] 1. The matrix asphalt is used as the binder, and the sodium lignosulfonate and the solid waste powder are processed into the solid waste-based mineral powder by wet ball milling. The binding force between the matrix asphalt and the solid waste-based mineral powder is strong, and the cohesion of the matrix asphalt can also be improved, so that the asphalt mixture after forming can have good low-temperature resistance.

[0035] 2. In the present application, the preferred solid waste powder includes red mud powder and waste concrete micro powder. The waste concrete micro powder has a certain alkalinity and a higher calcium content than the Bayer red mud powder, and has a good adsorption effect on the sodium lignosulfonate. The appropriate addition of the waste concrete micro powder helps to enhance the carrying capacity of the solid waste-based mineral powder for the sodium lignosulfonate, thereby improving the low-temperature resistance of the asphalt mixture after forming.

[0036] 3. The method of the present application newly adds the PET fiber on the basis of adding the lignin fiber. The PET fiber and the lignin fiber synergistically improve the stability of the free asphalt and jointly produce a toughening effect in the asphalt mixture, which helps to improve the low-temperature resistance of the asphalt mixture after forming. DETAILED DESCRIPTION

[0037] The present application is further described in detail below in combination with examples, preparation examples and comparative examples. The raw materials involved in the present application can be obtained by market purchase.

[0038] Preparation example of solid waste-based mineral powder

[0039] The following is illustrated by taking preparation example 1 as an example.

[0040] Preparation example 1

[0041] In this preparation example, the solid waste-based mineral powder is prepared according to the following method:

[0042] (1) The solid waste powder and sodium lignosulfonate are mixed according to a weight ratio of 80:1 to obtain a solid waste mixture; in this step, the solid waste powder is red mud powder with an average particle size of 70 μm, which is prepared by crushing and grinding the Bayer process red mud dried to a constant weight; in the chemical composition of the Bayer process red mud used to prepare the red mud powder, the mass fraction of calcium oxide is 8.6%, the content of silicon dioxide is 35.8%, and the content of aluminum oxide is 21.4%;

[0043] (2) The solid waste mixture and water are mixed to obtain a solid waste slurry, and the solid waste slurry is added to a wet ball milling device for ball milling; after the ball milling is completed, the solid waste slurry is dewatered to obtain a solid waste-based mineral powder.

[0044] As shown in Table 1, the differences between preparation examples 1-5 lie in the different average particle sizes of the red mud powder.

[0045] Table 1

[0046] Sample Preparation Example 1 Preparation Example 2 Preparation Example 3 Preparation Example 4 Preparation Example 5 Average particle size of red mud powder / μm 70 60 50 40 30

[0047] Preparation example 6

[0048] The difference between this preparation example and preparation example 5 lies in that the solid waste powder is mixed according to a weight ratio of 4.8:1 from red mud powder and waste concrete micro powder. The waste concrete micro powder is prepared according to the following method: the C40 waste concrete is crushed, then the coarse aggregate is removed by sieving using a 5 mm square hole screen, then the remaining material is ground, then the fine aggregate is removed using a 0.15 mm square hole screen, and then the remaining material is further ground to obtain waste concrete micro powder with an average particle size of 20 μm. As shown in Table 2, the differences between preparation examples 6-10 lie in the different average particle sizes of the waste concrete micro powder.

[0049] Table 2 Average particle size of waste concrete micro powder

[0050] Sample Preparation Example 6 Preparation Example 7 Preparation Example 8 Preparation Example 9 Preparation Example 10 Average particle size of waste concrete micro powder / μm 20 18 16 14 12

[0051] Preparation examples 11-14

[0052] As shown in Table 3, the differences between preparation examples 11-14 and preparation example 8 lie in that the solid waste powder and sodium lignosulfonate are compounded according to different weight ratios.

[0053] Table 3 Weight ratio of solid waste powder and sodium lignosulfonate

[0054] Sample Preparation Example 8 Preparation Example 11 Preparation Example 12 Preparation Example 13 Preparation Example 14 Solid waste powder: sodium lignosulfonate 80:1 70:1 60:1 50:1 40:1

[0055] The differentia of Preparation Examples 14-18 are shown in Table 4, which are different in the weight ratio of red mud powder and waste concrete micro powder.

[0056] Table 4 Weight ratio of red mud powder and waste concrete micro powder

[0057] Sample Preparation Example 14 Preparation Example 15 Preparation Example 16 Preparation Example 17 Preparation Example 18 Red mud powder: waste concrete micro powder 4.8:1 4.4:1 4.0:1 3.6:1 3.2:1

[0058] Examples

[0059] Examples 1-5

[0060] The following is described by taking Example 1 as an example.

[0061] Example 1

[0062] In this example, the low-temperature-resistant base asphalt mixture is made of the following raw materials: 74 kg of crushed stone, 13 kg of machine-made sand, 10 kg of solid waste-based mineral powder of Preparation Example 1, 5.9 kg of base asphalt, and 0.3 kg of lignin fiber. The crushed stone is basalt crushed stone, of which the weight of crushed stone with a particle size in the range of 10-13 mm is 44 kg, and the weight of crushed stone with a particle size in the range of 5-10 mm is 30 kg; the particle size range of the machine-made sand is 0.075-4.75 mm; the base asphalt is 110# base asphalt; the average single-fiber diameter of the lignin fiber is 15 μm, and the average length is 4 mm.

[0063] In this example, the low-temperature-resistant base asphalt mixture is prepared according to the following steps:

[0064] (1) Mix the crushed stone, machine-made sand, and solid waste-based mineral powder to obtain dry-mixed material, and heat the dry-mixed material at 180 °C (T1) for standby;

[0065] (2) Add the base asphalt preheated to 170 °C (T2) to the dry-mixed material and mix, stir at 180 °C (T3) for 10 min (t1) to obtain a mixture base, add lignin fiber to the mixture base and continue to heat and stir for 20 min (t2) to obtain a low-temperature-resistant base asphalt mixture.

[0066] The main differences of Examples 1-5 are shown in Table 5, which are mainly different in the raw material ratio and preparation conditions of the asphalt mixture.

[0067] Table 5 Raw material ratio and preparation conditions of the asphalt mixture

[0068]

[0069]

[0070] Examples 6-22

[0071] As shown in Table 6, Examples 6-22 differ from Example 5 in that the preparation example of solid waste-based mineral powder is different.

[0072] Table 6

[0073] Sample Preparation Example Sample Preparation Example Example 5 Preparation Example 1 Example 14 Preparation Example 10 Example 6 Preparation Example 2 Example 15 Preparation Example 11 Example 7 Preparation Example 3 Example 16 Preparation Example 12 Example 8 Preparation Example 4 Example 17 Preparation Example 13 Example 9 Preparation Example 5 Example 18 Preparation Example 14 Example 10 Preparation Example 6 Example 19 Preparation Example 15 Example 11 Preparation Example 7 Example 20 Preparation Example 16 Example 12 Preparation Example 8 Example 21 Preparation Example 17 Example 13 Preparation Example 9 Example 22 Preparation Example 18

[0074] Example 23

[0075] The difference between this example and Example 22 is that in step (2) of preparing the asphalt mixture, PET fibers with a single fiber diameter of 15 μm and an average length of 4 mm are added to the mixture matrix together with the lignin fibers, and the addition amount of the PET fibers (hereinafter referred to as the PET fiber ratio) is 0.8% of the weight of the base asphalt.

[0076] As shown in Table 7, Examples 23-27 differ in the PET fiber ratio.

[0077] Table 7 PET fiber ratio

[0078] Sample Example 23 Example 24 Example 25 Example 26 Example 27 PET fiber ratio / % 0.8 1.0 1.2 1.4 1.6

[0079] Comparative Example

[0080] Comparative Example 1

[0081] This preparation example provides an asphalt mixture made from the following components in parts by weight: 74 kg of crushed stone, 13 kg of fine aggregate, 10 kg of mineral powder, 5.9 kg of SBS modified asphalt, and 0.3 kg of lignin fibers. The crushed stone is basalt crushed stone, of which the weight of crushed stone with a particle size in the range of 10-13 mm is 44 kg, and the weight of crushed stone with a particle size in the range of 5-10 mm is 30 kg; the fine aggregate is machine-made sand with a particle size range of 0.075-4.75 mm; the mineral powder is limestone mineral powder with a 91.6% passing rate on a 0.075 mm sieve; the SBS modified asphalt is made from 110# base asphalt and 1301 SBS modifier, with a modifier dosage of 5%, and is processed using a high-speed shearing machine with a blending temperature of 160°C; the lignin fibers have an average single fiber diameter of 15 μm and an average length of 4 mm.

[0082] The asphalt mixture of this comparative example is prepared according to the following steps:

[0083] (1) Mix the crushed stone, machine-made sand, and solid waste-based mineral powder to obtain a dry mixture, and heat the dry mixture at 180°C for standby use;

[0084] (2) The matrix asphalt preheated to 170℃ is added into the dry mixture and mixed, stirred at 180℃ for 10 min to obtain a mixture matrix, lignin fibers are added into the mixture matrix and continue to be stirred for 20 min at constant temperature to obtain a low-temperature-resistant matrix asphalt mixture.

[0085] Comparative Example 2

[0086] The difference between the present comparative example and Comparative Example 1 is that the SBS modified asphalt is replaced by 110# matrix asphalt in equal quality.

[0087] Comparative Example 3

[0088] The difference between the present comparative example and Example 1 is that the solid waste-based mineral powder of Example 1 is replaced by the limestone mineral powder of Comparative Example 1.

[0089] Performance detection test method

[0090] According to the description of “GB / T 38948-2020 Asphalt Mixture Low-Temperature Anti-Cracking Performance Evaluation Method”, the bending strain energy density of the asphalt mixtures of Examples 1-27 and Comparative Examples 1-3 is detected at -5℃, and the low-temperature resistance is characterized by the bending strain energy density.

[0091] After the data of the bending strain energy density is measured, the ratio between the bending strain energy density of Examples 1-27 and Comparative Examples 1-3 and the bending strain energy density of Comparative Example 1 is calculated, and the ratio is recorded as the relative frost resistance, and the results are shown in Table 8.

[0092] Table 8 Relative Frost Resistance

[0093]

[0094]

[0095] It can be seen from Examples 1 and Comparative Examples 1-2 and Table 8 that the relative frost resistance measured in Example 1 is less than that of Comparative Example 1 but greater than that of Comparative Example 2, which indicates that after the SBS modified asphalt in Comparative Example 1 is replaced by matrix asphalt, the low-temperature resistance of the asphalt mixture has a relatively obvious decrease. However, the present application increases the bending strain energy density of the asphalt mixture when using matrix asphalt as the binder, which helps to overcome the defect of poor low-temperature resistance of the asphalt mixture on the premise of saving cost.

[0096] It can be seen from Examples 1 and Comparative Example 3 and Table 8 that the relative frost resistance measured in Example 1 is greater than that of Comparative Example 3, which indicates that the solid waste-based mineral powder of the present application plays a key role in improving the low-temperature resistance of the asphalt mixture when matrix asphalt is selected as the binder.

[0097] It can be seen from the combination of Embodiments 5-9 and Table 8 that reducing the particle size of the red mud powder helps to improve the low-temperature resistance of the asphalt mixture, and the low-temperature resistance of the asphalt mixture is relatively good when the average particle size of the red mud powder is 30-60 μm.

[0098] It can be seen from the combination of Embodiments 9, 10-14 and Table 8 that the relative frost resistance measured in Embodiments 10-14 is greater than that of Embodiment 9, indicating that replacing a part of the red mud powder with the waste concrete micro-powder on the basis of Preparation Example 5 and then using the obtained solid waste-based mineral powder to produce the asphalt mixture can improve the low-temperature resistance of the asphalt mixture. Embodiments 10-14 show a trend of first increasing and then decreasing, and the results of Embodiments 11-13 are better, indicating that as the particle size of the waste concrete micro-powder decreases, the improvement effect of the solid waste-based mineral powder on the low-temperature resistance of the asphalt mixture will be gradually affected, and therefore the particle size of the waste concrete micro-powder can be preferably 14-18 μm.

[0099] It can be seen from the combination of Embodiments 12, 15-18 and Table 8 that as the amount of sodium lignosulfonate is gradually increased, the measured relative frost resistance is also gradually improved, and the low-temperature resistance of the asphalt mixture is good when the solid waste powder and sodium lignosulfonate are compounded in a weight ratio of (40-60):1. In combination with the change trend of Embodiments 10-14, it can be seen that increasing the amount of sodium lignosulfonate on the basis of Embodiment 12 can overcome the negative effects caused by the too small particle size of the waste concrete micro-powder, and help to enhance the improvement effect of the solid waste-based mineral powder on the low-temperature resistance of the asphalt mixture.

[0100] It can be seen from the combination of Embodiments 18-22 and Table 8 that further increasing the proportion of the waste concrete micro-powder in the solid waste powder on the basis of Preparation Example 14, especially mixing the red mud powder and the waste concrete micro-powder in a weight ratio of (3.2-4.4):1, can better improve the low-temperature resistance of the asphalt mixture.

[0101] It can be seen from the combination of Embodiments 22, 23-27 and Table 8 that adding the PET fiber to the asphalt mixture can improve the low-temperature resistance of the asphalt mixture, and the low-temperature resistance of the asphalt mixture is relatively good when the addition amount of the PET fiber is 1.2-1.6% by weight of the base asphalt.

[0102] This specific embodiment is merely an explanation of the present application, and is not a limitation of the present application. Those skilled in the art can make modifications to the present embodiment without creative contribution after reading the present specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the Patent Law.

Claims

1. A low temperature resistant matrix asphalt mixture, characterized in that, The matrix asphalt mixture comprises components in parts by weight: 74-82 parts of crushed stone, 13-15 parts of machine-made sand, 10-12 parts of solid waste-based mineral powder, 5.9-7.9 parts of matrix asphalt, 0.3-2 parts of lignin fiber, the solid waste-based mineral powder being obtained by wet ball milling and drying of a solid waste mixture, components of the solid waste mixture including solid waste powder and sodium lignosulfonate compounded in a weight ratio of (40-80):1, the solid waste powder including red mud powder, the average particle size of the red mud powder being 30-60 μm, the solid waste-based mineral powder being prepared as follows: (1) mixing the solid waste powder and sodium lignosulfonate to obtain a solid waste mixture; (2) mixing the solid waste mixture and water to obtain a solid waste slurry, adding the solid waste slurry into a wet ball milling device for ball milling, and dehydrating the solid waste slurry after ball milling to obtain the solid waste-based mineral powder.

2. The low temperature resistant base asphalt mixture according to claim 1, characterized in that, The red mud powder is a Bayer process red mud powder, and the solid waste powder further includes waste concrete micro powder, the waste concrete micro powder being prepared as follows: crushing waste concrete, then screening out coarse aggregate, grinding the remaining material, then screening out fine aggregate, and continuously grinding the remaining material to obtain the waste concrete micro powder.

3. The low temperature resistant base asphalt mixture according to claim 2, wherein, The average particle size of the waste concrete micro powder is 14-18 μm.

4. The low temperature resistant base asphalt mixture according to claim 3, characterized in that, The solid waste powder and sodium lignosulfonate in the solid waste mixture are compounded in a weight ratio of (40-60):

1.

5. The low temperature resistant base asphalt mixture according to claim 4, wherein, The solid waste powder is obtained by mixing red mud powder and waste concrete micro powder in a weight ratio of (3.2-4.4):

1.

6. The method for preparing low-temperature resistant matrix asphalt mixture according to any one of claims 1-5, characterized in that, The method comprises the following steps: (1) mixing the crushed stone, machine-made sand and solid waste-based mineral powder to obtain dry mixed material, and preheating the dry mixed material at 180-190 ℃ for standby; (2) adding matrix asphalt preheated to 170-180 ℃ into the dry mixed material, mixing, stirring at 180-190 ℃ for 10-20 min to obtain a mixture base, adding lignin fiber into the mixture base and continuously heating and stirring for 20-30 min to obtain the matrix asphalt mixture.

7. The method of claim 6, wherein the low temperature resistant base asphalt mixture is prepared by mixing the base asphalt, the filler, the fiber, the wax, and the anti-stripping agent at a temperature of 120°C to 150°C. In step (2) of preparing the asphalt mixture, PET fiber is added into the mixture base together with the lignin fiber.

8. The method of claim 7, wherein the low temperature resistant base asphalt mixture is prepared by mixing the base asphalt, the filler, the fiber, the wax, and the anti-stripping agent at a temperature of 120°C to 150°C. The added amount of the PET fiber is 1.2-1.6% of the weight of the matrix asphalt.

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