A modified biochar rubber asphalt and its preparation method

Abstract

This invention belongs to the field of asphalt technology, specifically relating to a modified biochar rubber asphalt and its preparation method. The modified biochar rubber asphalt is made from the following raw materials in parts by weight: 80-100 parts base asphalt; 18-20 parts rubber powder; 4-8 parts stabilizer; and 4-8 parts modified biochar. The modified biochar is prepared using biochar and citric acid. This invention can effectively solve the rutting problem existing in current rubber asphalt pavements and further improve the rutting resistance of the pavement.

Description

Technical Field

[0001] This invention belongs to the field of asphalt technology, specifically relating to a modified biochar rubber asphalt and its preparation method. Background Technology

[0002] Asphalt is a commonly used raw material for road paving. Asphalt pavements have a long service life and maintain high quality and stability during use. However, under the long-term effects of temperature and vehicle loads, asphalt pavements can still develop problems such as rutting and shoving. Rubber is a highly elastic polymer material. Compared with pure asphalt, rubber-modified asphalt materials have better high and low temperature performance and fatigue resistance. my country produces a large amount of rubber products annually, and also generates a lot of waste rubber, such as waste tires from the automotive industry. Although this waste rubber has lost its original value, it still has advantages in the preparation of asphalt materials. Therefore, crushing waste rubber into powder and adding it to asphalt can not only improve the performance of asphalt, but also provide a practical and efficient way to reuse waste rubber.

[0003] Biochar is a solid residue and byproduct produced after the pyrolysis of biomass. In recent years, this material has been widely used in soil carbon sequestration and fertilization, as well as in sewage treatment. Similar to carbon black formed by the pyrolysis of waste tires, it has the basic properties and structure of carbon, with well-developed pores and a wide range of sources. Therefore, it can be used as a modifier to improve the various properties of asphalt.

[0004] Compared to ordinary base asphalt, rubberized asphalt has a higher viscosity, and consequently, rubberized asphalt pavements exhibit better high-temperature rutting resistance. However, under continuous vehicle loads, rutting problems still exist in rubberized asphalt pavements, indicating significant room for improvement in their rutting resistance. To address these issues, this invention discloses a rubberized asphalt with improved rutting resistance. Summary of the Invention

[0005] To address the technical problem of improving the rutting resistance of asphalt pavements, this invention provides a modified biochar rubber asphalt and its preparation method.

[0006] The purpose of this invention is to provide a modified biochar rubber asphalt, made from the following raw materials in parts by weight:

[0007] 80-100 parts of base asphalt, 18-20 parts of rubber powder, 4-8 parts of stabilizer, and 4-8 parts of modified biochar;

[0008] The modified biochar was prepared using biochar and citric acid.

[0009] Preferably, in the above-mentioned modified biochar rubber asphalt, the stabilizer is a mixture of stearic acid and maleic anhydride.

[0010] Preferably, in the above-mentioned modified biochar rubber asphalt, the mass ratio of stearic acid to maleic anhydride in the stabilizer is 1:1-2.

[0011] Preferably, the modified biochar rubber asphalt is prepared by the following method: citric acid and biochar are thoroughly mixed at a mass ratio of 1:100-120, water equivalent to 10-15% of the total mass of the mixture is added, and the moisture is removed in an oven at 90-100℃ to obtain modified biochar.

[0012] Preferably, in the above-mentioned modified biochar rubber asphalt, the base asphalt is road petroleum asphalt, such as No. 70 road petroleum asphalt.

[0013] Preferably, in the above-mentioned modified biochar rubber asphalt, the rubber powder is a 40-60 mesh powder made from waste rubber.

[0014] Preferably, in the above-mentioned modified biochar rubber asphalt, the waste rubber is waste tire rubber.

[0015] This invention provides a method for preparing modified biochar rubber asphalt, comprising the following steps:

[0016] Prepare each raw material according to the weight ratio;

[0017] Heat the base asphalt to 160℃, add the stabilizer, and mix and stir at 160℃ for 15-30 minutes to obtain material A;

[0018] Rubber powder and modified biochar were mixed at room temperature to obtain material B;

[0019] After mixing material A and material B, the mixture is sheared at 170-190℃ for 0.5-1h using a high-speed shearing apparatus to obtain modified biochar rubber asphalt.

[0020] Furthermore, in the above-mentioned method for preparing modified biochar rubber asphalt, when preparing material A, the asphalt heating temperature is 160℃, and after adding the stabilizer, the stirring rate is 400-600 rpm, the stirring temperature is 160℃, and the stirring time is 15-30 min.

[0021] Furthermore, in the above-mentioned method for preparing modified biochar rubber asphalt, when material A and material B are mixed, the shear rate is 3000-5000 rpm, the stirring temperature is 170-190℃, and the mixing time is 0.5-1h.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The stabilizer of this invention can be fully mixed with base asphalt, rubber powder, and modified biochar, thereby improving the dispersion of rubber powder and modified biochar in base asphalt and increasing the stability of asphalt.

[0024] The modified biochar described in this invention possesses excellent porous structure and physical properties. Citric acid modification removes ash and impurities from the biochar surface, increasing its porosity and pore size. When the modified biochar is thoroughly mixed with rubber powder, the mixture retains both the elastic properties of rubber and the advantages of the well-developed pores of the modified biochar. When this mixture is added to asphalt and thoroughly mixed, the lightweight components in the asphalt enter the pores of the modified biochar and fully combine with it, improving the performance of the asphalt and mitigating its tendency to segregate. The prepared modified biochar rubber asphalt mixture exhibits good rutting resistance and stability. Attached Figure Description

[0025] Figure 1 The figure shows the results of the dynamic stability test of asphalt mixture. Detailed Implementation

[0026] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments and accompanying drawings.

[0027] Unless otherwise specified, all reagents used in this invention are commercially available, and all methods used are conventional techniques in the art.

[0028] In the description of this invention, the biochar raw material used to prepare the modified biochar and the ordinary biochar raw material used in Comparative Example 3 are the same, both being corn straw biochar with a particle size of 200 mesh. Of course, those skilled in the art can replace the biochar with biochar produced by other manufacturers, ensuring the biochar particle size is between 100-200 mesh. The modified biochar rubber asphalt produced according to the method of this application will achieve technical effects comparable to those of the embodiments of this invention.

[0029] Example 1

[0030] A modified biochar rubber asphalt, characterized in that it is made from the following raw materials in parts by weight:

[0031] 80 parts base asphalt, 20 parts rubber powder, 4 parts stabilizer, and 4 parts modified biochar;

[0032] The stabilizer is a mixture of stearic acid and maleic anhydride, wherein the mass ratio of stearic acid to maleic anhydride in the stabilizer is 1:1.

[0033] The modified biochar is prepared as follows: Citric acid and biochar are thoroughly mixed at a mass ratio of 1:100, water equivalent to 10% of the total mass of the mixture is added, and the mixture is stirred again. The mixture is kept at 80°C for 15 minutes and then dried at 100°C to obtain the modified biochar.

[0034] The base asphalt is No. 70 road petroleum asphalt.

[0035] The rubber powder is a 40-mesh powder made from ground waste rubber, specifically waste automobile tires. Because automobile tires have strict production standards, this type of waste tire is chosen for making asphalt material due to its low pollution level and easy quality control.

[0036] The preparation method of modified biochar rubber asphalt includes the following steps:

[0037] Prepare each raw material according to the weight ratio of the raw materials for modified biochar rubber asphalt;

[0038] The base asphalt was placed in an asphalt mixing tank and heated to 160°C. After adding the stabilizer, the temperature was maintained at 160°C, and the mixture was stirred continuously at a speed of 600 rpm for 30 minutes to obtain material A.

[0039] Rubber powder and modified biochar were mixed at room temperature to obtain material B;

[0040] Material A and material B were mixed and stirred continuously at 5000 rpm for 1 hour at 180°C using a high-speed shear apparatus to obtain modified biochar rubber asphalt.

[0041] Example 2

[0042] A modified biochar rubber asphalt, characterized in that it is made from the following raw materials in parts by weight:

[0043] 80 parts base asphalt, 20 parts rubber powder, 6 parts stabilizer, and 4 parts modified biochar;

[0044] The stabilizer is a mixture of stearic acid and maleic anhydride, wherein the mass ratio of stearic acid to maleic anhydride in the stabilizer is 1:1.

[0045] The modified biochar is prepared as follows: Citric acid and biochar are thoroughly mixed at a mass ratio of 1:100, water equivalent to 10% of the total mass of the mixture is added, and the mixture is stirred again. The mixture is kept at 80°C for 15 minutes and then dried at 100°C to obtain the modified biochar.

[0046] The base asphalt is No. 70 road petroleum asphalt.

[0047] The rubber powder is a 40-mesh powder made from waste rubber, which is waste car tires.

[0048] The preparation method of modified biochar rubber asphalt includes the following steps:

[0049] Prepare each raw material according to the weight ratio of the raw materials for modified biochar rubber asphalt;

[0050] The base asphalt was placed in an asphalt mixing tank and heated to 160°C. After adding the stabilizer, the temperature was maintained at 160°C, and the mixture was stirred continuously at a speed of 600 rpm for 30 minutes to obtain material A.

[0051] Rubber powder and modified biochar were mixed at room temperature to obtain material B;

[0052] Material A and material B were mixed and stirred continuously at 5000 rpm for 1 hour at 180°C using a high-speed shear apparatus to obtain modified biochar rubber asphalt.

[0053] Example 3

[0054] A modified biochar rubber asphalt, characterized in that it is made from the following raw materials in parts by weight:

[0055] 80 parts base asphalt, 20 parts rubber powder, 8 parts stabilizer, and 4 parts modified biochar;

[0056] The stabilizer is a mixture of stearic acid and maleic anhydride, wherein the mass ratio of stearic acid to maleic anhydride in the stabilizer is 1:1.

[0057] The modified biochar is prepared as follows: Citric acid and biochar are thoroughly mixed at a mass ratio of 1:100, water equivalent to 10% of the total mass of the mixture is added, and the mixture is stirred again. The mixture is kept at 80°C for 15 minutes and then dried at 100°C to obtain the modified biochar.

[0058] The base asphalt is No. 70 road petroleum asphalt.

[0059] The rubber powder is a 40-mesh powder made from waste rubber, which is waste car tires.

[0060] The preparation method of modified biochar rubber asphalt includes the following steps:

[0061] Prepare each raw material according to the weight ratio of the raw materials for modified biochar rubber asphalt;

[0062] The base asphalt was placed in an asphalt mixing tank and heated to 160°C. After adding the stabilizer, the temperature was maintained at 160°C, and the mixture was stirred continuously at a speed of 600 rpm for 30 minutes to obtain material A.

[0063] Rubber powder and modified biochar were mixed at room temperature to obtain material B;

[0064] Material A and material B were mixed and stirred continuously at 5000 rpm for 1 hour at 170°C using a high-speed shear apparatus to obtain modified biochar rubber asphalt.

[0065] Example 4

[0066] A modified biochar rubber asphalt, characterized in that it is made from the following raw materials in parts by weight:

[0067] 80 parts base asphalt, 20 parts rubber powder, 4 parts stabilizer, and 6 parts modified biochar;

[0068] The stabilizer is a mixture of stearic acid and maleic anhydride, wherein the mass ratio of stearic acid to maleic anhydride in the stabilizer is 1:1.

[0069] The modified biochar is prepared as follows: Citric acid and biochar are thoroughly mixed at a mass ratio of 1:100, water equivalent to 10% of the total mass of the mixture is added, and the mixture is stirred again. The mixture is kept at 80°C for 15 minutes and then dried at 100°C to obtain the modified biochar.

[0070] The base asphalt is No. 70 road petroleum asphalt.

[0071] The rubber powder is a 40-mesh powder made from waste rubber, which is waste car tires.

[0072] The preparation method of modified biochar rubber asphalt includes the following steps:

[0073] Prepare each raw material according to the weight ratio of the raw materials for modified biochar rubber asphalt;

[0074] The base asphalt was placed in an asphalt mixing tank and heated to 160°C. After adding the stabilizer, the temperature was maintained at 160°C, and the mixture was stirred continuously at a speed of 600 rpm for 30 minutes to obtain material A.

[0075] Rubber powder and modified biochar were mixed at room temperature to obtain material B;

[0076] Material A and material B were mixed and stirred continuously at 5000 rpm for 1 hour at 180°C using a high-speed shear apparatus to obtain modified biochar rubber asphalt.

[0077] Example 5

[0078] A modified biochar rubber asphalt, characterized in that it is made from the following raw materials in parts by weight:

[0079] 80 parts base asphalt, 20 parts rubber powder, 4 parts stabilizer, and 8 parts modified biochar;

[0080] The stabilizer is a mixture of stearic acid and maleic anhydride, wherein the mass ratio of stearic acid to maleic anhydride in the stabilizer is 1:1.

[0081] The modified biochar is prepared as follows: Citric acid and biochar are thoroughly mixed at a mass ratio of 1:100, water equivalent to 10% of the total mass of the mixture is added, and the mixture is stirred again. The mixture is kept at 80°C for 15 minutes and then dried at 100°C to obtain the modified biochar.

[0082] The base asphalt is No. 70 road petroleum asphalt.

[0083] The rubber powder is a 40-mesh powder made from waste rubber, which is waste car tires.

[0084] The preparation method of modified biochar rubber asphalt includes the following steps:

[0085] Prepare each raw material according to the weight ratio of the raw materials for modified biochar rubber asphalt;

[0086] The base asphalt was placed in an asphalt mixing tank and heated to 160°C. After adding the stabilizer, the temperature was maintained at 160°C, and the mixture was stirred continuously at a speed of 500 rpm for 15 minutes to obtain material A.

[0087] Rubber powder and modified biochar were mixed at room temperature to obtain material B;

[0088] Material A and material B were mixed and stirred continuously at 5000 rpm for 1 hour at 180°C using a high-speed shear apparatus to obtain modified biochar rubber asphalt.

[0089] Example 6

[0090] A modified biochar rubber asphalt, characterized in that it is made from the following raw materials in parts by weight:

[0091] 90 parts base asphalt, 18 parts rubber powder, 6 parts stabilizer, and 6 parts modified biochar;

[0092] The stabilizer is a mixture of stearic acid and maleic anhydride, wherein the mass ratio of stearic acid to maleic anhydride in the stabilizer is 1:2.

[0093] The modified biochar is prepared as follows: Citric acid and biochar are thoroughly mixed at a mass ratio of 1:110, water equivalent to 12% of the total mass of the mixture is added, and the mixture is stirred again. The mixture is kept at 90°C for 20 minutes and then dried at 100°C to obtain the modified biochar.

[0094] The base asphalt is No. 70 road petroleum asphalt.

[0095] The rubber powder is a 60-mesh powder made from waste rubber, and the waste rubber is waste truck tires.

[0096] The preparation method of modified biochar rubber asphalt includes the following steps:

[0097] Prepare each raw material according to the weight ratio of the raw materials for modified biochar rubber asphalt;

[0098] The base asphalt was placed in an asphalt mixing tank and heated to 160°C. After adding the stabilizer, the temperature was maintained at 160°C, and the mixture was stirred continuously at a speed of 400 rpm for 30 minutes to obtain material A.

[0099] Rubber powder and modified biochar were mixed at room temperature to obtain material B;

[0100] Material A and material B were mixed and stirred continuously at 3000 rpm for 1 hour at 190°C using a high-speed shear apparatus to obtain modified biochar rubber asphalt.

[0101] Example 7

[0102] A modified biochar rubber asphalt, characterized in that it is made from the following raw materials in parts by weight:

[0103] 100 parts base asphalt, 20 parts rubber powder, 8 parts stabilizer, and 6 parts modified biochar;

[0104] The stabilizer is a mixture of stearic acid and maleic anhydride, wherein the mass ratio of stearic acid to maleic anhydride in the stabilizer is 1:1.

[0105] The modified biochar is prepared as follows: Citric acid and biochar are thoroughly mixed at a mass ratio of 1:120, water equivalent to 15% of the total mass of the mixture is added, and the mixture is stirred again. The mixture is kept at 80°C for 20 minutes and then dried at 90°C to obtain the modified biochar.

[0106] The base asphalt is No. 70 road petroleum asphalt.

[0107] The rubber powder is a 60-mesh powder made from waste rubber, which is waste car tires.

[0108] The preparation method of modified biochar rubber asphalt includes the following steps:

[0109] Prepare each raw material according to the weight ratio of the raw materials for modified biochar rubber asphalt;

[0110] The base asphalt was placed in an asphalt mixing tank and heated to 160°C. After adding the stabilizer, the temperature was maintained at 160°C, and the mixture was stirred continuously at a speed of 600 rpm for 30 minutes to obtain material A.

[0111] Rubber powder and modified biochar were mixed at room temperature to obtain material B;

[0112] Material A and material B were mixed and stirred continuously at 4000 rpm for 0.5 h at 190°C using a high-speed shear apparatus to obtain modified biochar rubber asphalt.

[0113] Example 8

[0114] A modified biochar rubber asphalt, characterized in that it is made from the following raw materials in parts by weight:

[0115] 80 parts base asphalt, 20 parts rubber powder, 4 parts stabilizer, and 4 parts modified biochar;

[0116] The stabilizer is a mixture of stearic acid and maleic anhydride, wherein the mass ratio of stearic acid to maleic anhydride in the stabilizer is 1:1.

[0117] The modified biochar is prepared as follows: Citric acid and biochar are thoroughly mixed at a mass ratio of 1:115, water equivalent to 15% of the total mass of the mixture is added, and the mixture is stirred again. The mixture is kept at 90°C for 15 minutes and then dried at 100°C to obtain the modified biochar.

[0118] The base asphalt is No. 70 road petroleum asphalt.

[0119] The rubber powder is a 60-mesh powder made from waste rubber, which is waste car tires.

[0120] The preparation method of modified biochar rubber asphalt includes the following steps:

[0121] Prepare each raw material according to the weight ratio of the raw materials for modified biochar rubber asphalt;

[0122] The base asphalt was placed in an asphalt mixing tank and heated to 160°C. After adding the stabilizer, the temperature was maintained at 160°C, and the mixture was stirred continuously at a speed of 600 rpm for 30 minutes to obtain material A.

[0123] Rubber powder and modified biochar were mixed at room temperature to obtain material B;

[0124] Material A and material B were mixed and stirred continuously at 3000 rpm for 0.5 h at 180°C using a high-speed shear apparatus to obtain modified biochar rubber asphalt.

[0125] Comparative Example 1

[0126] A modified biochar rubber asphalt, characterized in that it is made from the following raw materials in parts by weight:

[0127] 80 parts base bitumen, 20 parts rubber powder, and 4 parts modified biochar;

[0128] The modified biochar is prepared as follows: Citric acid and biochar are thoroughly mixed at a mass ratio of 1:100, water equivalent to 10% of the total mass of the mixture is added, and the mixture is stirred again. The mixture is kept at 80°C for 15 minutes and then dried at 100°C to obtain the modified biochar.

[0129] The base asphalt is No. 70 road petroleum asphalt.

[0130] The rubber powder is a 40-mesh powder made from waste rubber, which is waste car tires.

[0131] The preparation method of modified biochar rubber asphalt includes the following steps:

[0132] Prepare each raw material according to the weight ratio of the raw materials for modified biochar rubber asphalt;

[0133] The base asphalt was placed in an asphalt mixing tank and heated to 160°C. The temperature was maintained at 160°C, and the mixture was stirred continuously at a speed of 600 rpm for 30 minutes to obtain material A.

[0134] Rubber powder and modified biochar were mixed at room temperature to obtain material B;

[0135] Material A and material B were mixed and stirred continuously at 5000 rpm for 1 hour at 180°C using a high-speed shear apparatus to obtain modified biochar rubber asphalt.

[0136] Comparative Example 2

[0137] A modified rubber asphalt, characterized in that it is made from the following raw materials in parts by weight:

[0138] 80 parts base asphalt, 20 parts rubber powder, and 4 parts stabilizer;

[0139] The stabilizer is a mixture of stearic acid and maleic anhydride, wherein the mass ratio of stearic acid to maleic anhydride in the stabilizer is 1:1.

[0140] The base asphalt is No. 70 road petroleum asphalt.

[0141] The rubber powder is a 40-mesh powder made from waste rubber, which is waste car tires.

[0142] The preparation method of modified rubber asphalt includes the following steps:

[0143] Prepare each raw material according to the weight ratio of the raw materials in the modified rubber asphalt;

[0144] The base asphalt was placed in an asphalt mixing tank and heated to 160°C. After adding the stabilizer, the temperature was maintained at 160°C, and the mixture was stirred continuously at a speed of 600 rpm for 30 minutes to obtain the mixture.

[0145] The above mixture was mixed with rubber powder and stirred continuously at 5000 rpm for 1 hour at 180°C using a high-speed shear apparatus to obtain modified biochar rubber asphalt.

[0146] Comparative Example 3

[0147] A modified biochar rubber asphalt, characterized in that it is made from the following raw materials in parts by weight:

[0148] 80 parts base asphalt, 20 parts rubber powder, 4 parts stabilizer, and 4 parts ordinary biochar;

[0149] The stabilizer is a mixture of stearic acid and maleic anhydride, wherein the mass ratio of stearic acid to maleic anhydride in the stabilizer is 1:1.

[0150] The base asphalt is No. 70 road petroleum asphalt.

[0151] The rubber powder is a 40-mesh powder made from waste rubber, which is waste car tires.

[0152] The preparation method of modified biochar rubber asphalt includes the following steps:

[0153] Prepare each raw material according to the weight ratio of the raw materials for modified biochar rubber asphalt;

[0154] The base asphalt was placed in an asphalt mixing tank and heated to 160°C. After adding the stabilizer, the temperature was maintained at 160°C, and the mixture was stirred continuously at a speed of 600 rpm for 30 minutes to obtain material A.

[0155] Rubber powder and ordinary biochar are mixed at room temperature to obtain material B;

[0156] Material A and material B were mixed and stirred continuously at 5000 rpm for 1 hour at 180°C using a high-speed shear apparatus to obtain modified biochar rubber asphalt.

[0157] Experimental Section

[0158] The softening point, ductility, penetration, and Brinell viscosity of the modified biochar rubber asphalt were determined according to the methods in the "Test Procedures for Highway Asphalt and Asphalt Mixtures" (JTG E20-2011). The high-temperature rutting resistance of the modified biochar rubber asphalt mixture was also determined. The results are shown in Table 1 and... Figure 1 .

[0159] Table 1 Performance Indicators of Modified Biochar Rubber Asphalt

[0160]

[0161]

[0162] The high-temperature performance of modified biochar rubber asphalt can be evaluated by testing its basic properties. A comparison of Examples 1-3 and Comparative Example 1 in Table 1 shows that the basic properties of the asphalt improve with increasing stabilizer dosage. A comparison of Examples 1, 4-5, and Comparative Example 2 shows that the softening point, penetration, and viscosity of the modified asphalt increase with increasing modified biochar dosage, indicating improved high-temperature performance. A comparison of Example 1 and Comparative Example 3 shows that the high-temperature performance of the modified biochar rubber asphalt is significantly better than that of ordinary biochar rubber asphalt.

[0163] The dynamic stability of asphalt mixtures directly affects the rutting resistance of asphalt pavements. Figure 1 The results are the dynamic stability test results of asphalt mixtures in Examples 1-8 and Comparative Examples 1-3. It can be seen that the dynamic stability of the examples is higher than that of the comparative examples, indicating that modified biochar and stabilizers can improve the rutting resistance of asphalt mixtures. The results of Examples 1-5 further illustrate that with the increase of modified biochar and stabilizer dosage, the dynamic stability of asphalt mixtures will further increase, and its rutting resistance will gradually improve.

[0164] The comparison between Examples 1 and Examples 6-8 illustrates that different treatment conditions and preparation methods have a certain impact on the performance of asphalt and asphalt mixtures. When multiple conditions change simultaneously, the overall pattern shown by the scheme is not obvious. This indicates that, in addition to modified biochar and stabilizers, other conditions also have a certain impact on the performance of modified asphalt and its mixtures. In actual production, while ensuring the dosage of modified biochar and stabilizers, attention should also be paid to the overall impact of the scheme on its performance.

[0165] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A modified biochar rubber asphalt, characterized in that, Made from the following parts by weight of raw materials: 80-100 parts of base asphalt, 18-20 parts of rubber powder, 4-8 parts of stabilizer, and 4-8 parts of modified biochar; The modified biochar was prepared using biochar and citric acid. The modified biochar is prepared as follows: Citric acid and biochar are thoroughly mixed at a mass ratio of 1:100-120, water equivalent to 10-15% of the total mass of the mixture is added, and the mixture is stirred again. After maintaining the temperature at 80-90℃ for 15-20 minutes, the moisture is dried to obtain the modified biochar. The stabilizer is a mixture of stearic acid and maleic anhydride; In the stabilizer, the mass ratio of stearic acid to maleic anhydride is 1:1-2.

2. The modified biochar rubber asphalt according to claim 1, characterized in that, The base asphalt is road petroleum asphalt.

3. The modified biochar rubber asphalt according to claim 1, characterized in that, The rubber powder is a 40-60 mesh powder made from ground waste rubber.

4. A modified biochar rubber asphalt according to claim 3, characterized in that, The waste rubber is waste tire rubber.

5. The method for preparing modified biochar rubber asphalt according to claim 1, characterized in that, Includes the following steps: Prepare each raw material according to the weight ratio; Heat the base asphalt to 160℃, add the stabilizer, and mix and stir at 160℃ for 15-30 minutes to obtain material A; Rubber powder and modified biochar were mixed at room temperature to obtain material B; After mixing material A and material B, the mixture is sheared at 170-190℃ for 0.5-1h using a high-speed shearing apparatus to obtain modified biochar rubber asphalt.

6. The method for preparing modified biochar rubber asphalt according to claim 5, characterized in that, The mixing method is as follows: place the materials to be mixed in an asphalt mixing tank and stir.

7. The method for preparing modified biochar rubber asphalt according to claim 6, characterized in that, When preparing material A, the stirring speed is 400-600 rpm; When material A and material B are mixed, the shear rate is 3000-5000 rpm.

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