CN114853378A

CN114853378A - Drainage type asphalt mixture and preparation method thereof

Info

Publication number: CN114853378A
Application number: CN202210567311.0A
Authority: CN
Inventors: 陈士平; 范金鹏; 湛孝伟; 单跃; 胡成
Original assignee: Nanjing Shengke Road New Material Technology Co ltd
Current assignee: Nanjing Shengke Road New Material Technology Co ltd
Priority date: 2022-05-24
Filing date: 2022-05-24
Publication date: 2022-08-05

Abstract

The application relates to the technical field of building materials for road construction, and particularly discloses a drainage type asphalt mixture and a preparation method thereof. The drainage type asphalt mixture comprises the following raw materials in parts by mass: 120-150 parts of aggregate, 5-10 parts of filler, 12-20 parts of asphalt and 5-10 parts of rubber modifier, wherein the aggregate is obtained by soaking and pretreating with a polymethyl methacrylate solution. The asphalt mixture has better structural stability, and meanwhile, the hydrophobic property is greatly improved.

Description

Drainage type asphalt mixture and preparation method thereof

Technical Field

The application relates to the technical field of building materials for road construction, in particular to a drainage type asphalt mixture and a preparation method thereof.

Background

The drainage asphalt pavement is a novel asphalt mixture surface layer which has the porosity of about 20% after being compacted and can form a drainage channel in the mixture. Drainage bituminous paving is better to the discharge effect of rainwater, can effectively reduce the potential safety hazard that leads to because of the road surface is wet and smooth, and drainage bituminous paving's porous structure also has positive meaning to making an uproar to falling simultaneously.

Meanwhile, a drainage channel formed by the drainage type asphalt mixture is easy to damage in structure and poor in stability under the long-term rainwater infiltration and erosion, and further the service life of the drainage type asphalt pavement is influenced. In addition, after rainwater permeates into the structure from the drainage channel, the drainage performance is easily influenced greatly. Thus, the water resistance of the drainage asphalt mixture is also critical to its performance benefits.

Disclosure of Invention

In order to improve the hydrophobic property of the drainage type asphalt mixture, the application provides the drainage type asphalt mixture and the preparation method thereof.

In a first aspect, the application provides a drainage type asphalt mixture, which adopts the following technical scheme:

the drainage type asphalt mixture comprises the following raw materials in parts by mass: 120-150 parts of aggregate, 5-10 parts of filler, 12-20 parts of asphalt and 5-10 parts of rubber modifier, wherein the aggregate is obtained by soaking and pretreating with a polymethyl methacrylate solution.

By adopting the technical scheme, the aggregate and the filler are used as base materials, and the rubber modifier is used for modifying the asphalt, so that the viscosity of the asphalt can be effectively improved. And the fracture resistance and the cushioning performance of the mixture are improved to a certain degree under the influence of the material characteristics of the rubber modifier. In addition, the aggregate is obtained after the soaking pretreatment of the polymethyl methacrylate solution, and the polymethyl methacrylate has better viscosity and can be stably attached to the surface of the aggregate. And the polymethyl methacrylate has higher structural strength after being cured and has better hydrophobic property. Therefore, after the aggregate is soaked in the polymethyl methacrylate solution, a stable hydrophobic membrane layer exists on the surface of the aggregate after the solvent is volatilized, and the hydrophobic performance of the drainage type asphalt mixture is improved. In addition, the hydrophobic film layer formed on the surface of the aggregate has a good bonding effect with the asphalt, and the overall stability of the drainage asphalt mixture can be effectively improved.

Preferably, the aggregate is pretreated by soaking in polymethyl methacrylate solution, and the method specifically comprises the following steps: soaking treatment: cleaning aggregates, soaking the cleaned aggregates in a polymethyl methacrylate solution, hermetically soaking, filtering to obtain a crude pretreated aggregate product, and hermetically storing a filtrate;

and (3) drying treatment: and drying the crude pretreated aggregate to obtain the finished pretreated aggregate.

Through adopting above-mentioned technical scheme, soak the aggregate under airtight environment, can effectively reduce and soak the in-process and lead to the too thick condition of polymethyl methacrylate solution because of solvent volatilize to can effectively reduce the condition that leads to the separation difficulty of aggregate because of polymethyl methacrylate solution viscosity is too high. And meanwhile, the aggregate is soaked in a closed environment, and the concentration of the solution is relatively constant, so that the thickness of a hydrophobic membrane layer formed on the surface of the aggregate is appropriate, and the structural stability is good while the hydrophobic property of the drainage type asphalt mixture is improved.

Preferably, the mass concentration of the polymethyl methacrylate solution is 10g/L to 20 g/L.

By adopting the technical scheme, the polymethyl methacrylate solution with the mass concentration can form a stable hydrophobic film layer with proper thickness on the surface of the aggregate.

Preferably, the organic solvent is a mixture of N, N-dimethylformamide and chloroform according to a mass ratio of 1 (1.5-3).

By adopting the technical scheme, the N, N-dimethylformamide and the chloroform are compounded according to the mass ratio and can better dissolve the polymethyl methacrylate, so that a stable polymethyl methacrylate solution is obtained. And the volatilization speed of the organic solvent obtained by compounding is proper, which is favorable for the polymethyl methacrylate to be attached to the surface of the aggregate.

Preferably, the crude pretreated aggregate obtained in the soaking step is dried after being soaked for the second time, and the specific operations are as follows:

adding dimethyl silicone oil and a silane coupling agent into the filtrate hermetically stored in the soaking treatment step to obtain a secondary soaking solution; then soaking the crude pretreated aggregate in a secondary soaking solution, hermetically soaking, filtering to obtain a secondary crude pretreated aggregate, and hermetically storing a secondary filtrate; and then carrying out subsequent drying treatment to obtain the finished product of the pretreated aggregate.

By adopting the technical scheme, the dimethyl silicone oil is added for secondary soaking, the dimethyl silicone oil is attached to the hydrophobic membrane layer on the surface of the aggregate, and the combination effect of the polymethyl methacrylate and the dimethyl silicone oil is better. And simultaneously, under the action of a silane coupling agent, methyl methacrylate and dimethyl silicone oil are crosslinked to a certain degree to form a stable three-dimensional crosslinked network structure, so that a hydrophobic membrane layer with better hydrophobic property is formed, and the structural stability of the hydrophobic membrane layer is further optimized.

Preferably, in the secondary soaking treatment step, the mass concentration of the dimethyl silicone oil in the secondary soaking solution is 15 g/L-20 g/L.

By adopting the technical scheme, the mass concentration of the dimethyl silicone oil in the secondary soaking solution is controlled to be 15 g/L-20 g/L, and a more stable hydrophobic membrane layer can be formed by matching with the residual polymethyl methacrylate in the secondary soaking solution.

Preferably, the rubber modifier is a mixture of styrene butadiene rubber and nano silicon dioxide according to a mass ratio of (20-30): 1.

By adopting the technical scheme, the styrene butadiene rubber and the nano silicon dioxide are used as the rubber modifier, wherein the styrene butadiene rubber can effectively improve the durability and the high-temperature performance of the asphalt, and has a relatively obvious improvement effect on the viscosity of the asphalt. In addition, the shock absorption performance and the fracture resistance of the obtained asphalt mixture are improved to a certain degree under the influence of the physical properties of the styrene butadiene rubber. However, the overall adhesion between styrene butadiene rubber and asphalt is general, and the required asphalt viscosity is difficult to achieve only by the modification effect of styrene butadiene rubber.

Therefore, the nano silicon dioxide is further compounded and used for modification, and the nano silicon dioxide not only can effectively improve the stability of the asphalt, but also has positive significance for improving the heat resistance of the asphalt. In addition, the nano silicon dioxide has better dispersion effect in the system and can fully act between the styrene butadiene rubber and the asphalt; and a network structure is easily formed between the nano silicon dioxide and the styrene butadiene rubber, so that the styrene butadiene rubber can expand in the mutual collision process, the overall bonding degree between the styrene butadiene rubber and the asphalt is improved, the overall stability of the asphalt is improved, and the required high-viscosity asphalt is obtained.

Preferably, the aggregate and filler are integrally graded as follows:

the sieve plate with the thickness of the sieve plate is characterized in that the 19mm sieve mesh passing rate is 100%, the 16mm sieve mesh passing rate is 90-100%, the 13.2mm sieve mesh passing rate is 60-80%, the 9.5mm sieve mesh passing rate is 50-60%, the 4.75mm sieve mesh passing rate is 15-23%, the 2.36mm sieve mesh passing rate is 10-20%, the 1.18mm sieve mesh passing rate is 5-14%, the 0.6mm sieve mesh passing rate is 4-12%, the 0.3mm sieve mesh passing rate is 3-10%, the 0.15mm sieve mesh passing rate is 3-8%, and the 0.075mm sieve mesh passing rate is 2-5%.

By adopting the technical scheme, the aggregate and the filler are screened according to the open grading mode, the finally obtained asphalt mixture void ratio is proper, and the requirement of the drainage type asphalt pavement is met, so that the drainage performance of the drainage type asphalt pavement formed by the asphalt mixture is improved.

In a second aspect, the application provides a preparation method of a drainage type asphalt mixture, which adopts the following technical scheme: a preparation method of a drainage type asphalt mixture comprises the following steps:

and (3) asphalt modification treatment: mixing and stirring the asphalt and the rubber modifier under a heating state to obtain modified asphalt for later use;

preparing an asphalt mixture: and mixing and stirring the modified asphalt, the aggregate and the filler under a heating state to obtain a finished asphalt mixture.

By adopting the technical scheme, the rubber modifier is firstly utilized to modify the asphalt to obtain the high-viscosity asphalt, and then the modified asphalt, the aggregate and the filler are mixed, so that the obtained asphalt mixture has higher structural stability.

Preferably, in the step of preparing the asphalt mixture, the aggregate and the filler are added, and then the secondary filtrate is added for mixing and stirring to obtain the finished asphalt mixture.

By adopting the technical scheme, in the preparation process of the asphalt mixture, the secondary filtrate is added for mixing, and because the polymethyl methacrylate, the simethicone and the silane coupling agent are remained in the secondary filtrate, firstly, the polymethyl methacrylate has better viscosity, and the improvement of the combination stability of all materials in the asphalt mixture is facilitated. Meanwhile, in the mixing and stirring process, the organic solvent in the secondary filtrate is heated to accelerate volatilization, and finally the organic solvent basically cannot remain in the system, namely, the obvious negative influence on the asphalt mixture cannot be caused. In addition, a hydrophobic structure formed by polymethyl methacrylate and dimethyl silicone oil finally remaining in the system is inserted into the system, so that the hydrophobic performance of the asphalt mixture is further improved. And the silane coupling agent also has positive significance on the stability of an asphalt system, namely the addition of the secondary filtrate into the asphalt system has more prominent and obvious positive significance.

In summary, the present application has the following beneficial effects:

1. the aggregate is a pre-treated aggregate obtained by soaking the aggregate in a polymethyl methacrylate solution, and the polymethyl methacrylate is gradually attached to the surface of the aggregate in the soaking process and forms a relatively stable hydrophobic membrane layer, so that the hydrophobic property of the asphalt mixture is improved; in addition, the hydrophobic membrane layer formed on the surface of the aggregate has higher strength and better combination effect with the asphalt, and is beneficial to improving the stability of the integral structure of the asphalt mixture.

2. According to the modified asphalt, the styrene butadiene rubber and the nano silicon dioxide are used as rubber modifiers, and on the basis that the styrene butadiene rubber improves the viscosity of the asphalt, the nano silicon dioxide can further improve the stability of an asphalt system and the overall viscosity between the styrene butadiene rubber and the asphalt, so that the modified asphalt with high and stable viscosity is obtained.

3. According to the method, the secondary soaking liquid is obtained by adding the dimethyl silicone oil and the silane coupling agent into the primary filtrate, and after the aggregate is soaked for the second time, the structure of the hydrophobic membrane layer on the surface is more stable, and the hydrophobic property is further improved.

4. According to the application, the secondary filtrate is added in the preparation process of the asphalt mixture, the organic solvent is heated to be basically completely volatilized, and the polymethyl methacrylate, the dimethyl silicone oil and the silane coupling agent which are remained in the system have obvious positive significance on the asphalt mixture system, wherein the polymethyl methacrylate can improve the viscosity of the system, and can be matched with the dimethyl silicone oil to form an interpenetrating hydrophobic structure, so that the hydrophobic property of the asphalt mixture is further improved, and meanwhile, the silane coupling agent also has positive significance on the stability of the asphalt mixture system.

Detailed Description

The present application will be described in further detail with reference to examples and comparative examples, and all of the starting materials referred to in the present application are commercially available.

Preparation example of pretreated aggregate

Preparation example 1

A preparation method of pretreated aggregate comprises the following steps:

(1) soaking treatment: the aggregate was washed, and then 300kg of the washed aggregate was soaked in a polymethylmethacrylate solution to keep the polymethylmethacrylate solution submerged in the aggregate. Then soaking for 6h in a closed manner at room temperature, filtering to obtain a crude pretreated aggregate, and preserving the filtrate in a closed manner;

(2) and (3) drying treatment: drying the crude pretreated aggregate for 2 hours at the temperature of 60 ℃ to obtain the finished pretreated aggregate;

wherein the aggregate is basalt; the organic solvent of the polymethyl methacrylate solution is a mixture of N, N-dimethylformamide and chloroform according to the mass ratio of 1:2, and the mass concentration of the polymethyl methacrylate solution is 20 g/L.

Preparation example 2

A preparation method of pretreated aggregate comprises the following steps:

1. soaking treatment: the aggregate was washed, and then 300kg of the washed aggregate was soaked in a polymethylmethacrylate solution to keep the polymethylmethacrylate solution submerged in the aggregate. Then soaking for 6 hours in a closed manner at room temperature, filtering to obtain a crude pretreated aggregate product, and preserving the filtrate in a closed manner;

2. secondary soaking treatment: adding simethicone and 0.5kg of silane coupling agent KH-560 into the filtrate hermetically stored in the soaking step to obtain a secondary soaking solution, wherein the mass concentration of the simethicone in the secondary soaking solution is 15 g/L; then soaking the crude pretreated aggregate in a secondary soaking solution, soaking for 5 hours in a closed manner, filtering to obtain a secondary crude pretreated aggregate, and preserving a secondary filtrate in a closed manner;

(c) and (3) drying treatment: drying the crude pretreated aggregate for 2 hours at the temperature of 60 ℃ to obtain the finished pretreated aggregate;

Preparation example 3

The present preparation example differs from preparation example 1 in that (1) the mass concentration of the polymethyl methacrylate solution in the immersion treatment step is 10 g/L.

Preparation example 4

The present preparation example differs from preparation example 1 in that (1) the mass concentration of the polymethyl methacrylate solution in the immersion treatment step is 15 g/L.

Preparation example 5

The present preparation example differs from preparation example 1 in that (1) the mass concentration of the polymethyl methacrylate solution in the immersion treatment step is 5 g/L.

Preparation example 6

The present preparation example differs from preparation example 1 in that (1) the mass concentration of the polymethyl methacrylate solution in the immersion treatment step is 30 g/L.

Preparation example 7

The present preparation example differs from preparation example 1 in that (1) in the immersion treatment step, the organic solvent is a mixture of N, N-dimethylformamide and chloroform in a mass ratio of 1: 3.

Preparation example 8

The present preparation example differs from preparation example 1 in that (1) in the immersion treatment step, the organic solvent is a mixture of N, N-dimethylformamide and chloroform in a mass ratio of 1: 1.5.

Preparation example 9

The present production example is different from production example 1 in that (1) in the immersion treatment step, the organic solvent is N, N-dimethylformamide.

Preparation example 10

This preparation example is different from preparation example 1 in that (1) in the immersion treatment step, the organic solvent is chloroform.

Preparation example 11

The present preparation example differs from preparation example 1 in that (1) in the immersion treatment step, the organic solvent is acetone.

Preparation example 12

The present preparation example is different from preparation example 1 in that (1) in the immersion treatment step, the immersion process is performed in an open environment, that is, a sealing treatment is not performed.

Examples

The difference between the embodiments 1 to 5 is that the amount and the mixture ratio of the materials are different, and the embodiment 1 is taken as an example for explanation.

Example 1

The drainage type asphalt mixture comprises the following raw materials in mass: 130kg of aggregate, 6kg of filler, 15kg of asphalt and 7kg of rubber modifier;

wherein the aggregate is prepared in preparation example 1;

the filler is limestone mineral powder;

the asphalt is SBS asphalt;

the rubber modifier is a mixture of styrene butadiene rubber and nano-silica according to a mass ratio of 24:1, the particle size of the styrene butadiene rubber is 2-5 mm, and the particle size of the nano-silica is 30-50 nm;

and the aggregate and filler have the following overall gradation: the passing rate of 19mm sieve pores is 100%, the passing rate of 16mm sieve pores is 98.4%, the passing rate of 13.2mm sieve pores is 73.2%, the passing rate of 9.5mm sieve pores is 55.7%, the passing rate of 4.75mm sieve pores is 18.5%, the passing rate of 2.36mm sieve pores is 12.1%, the passing rate of 1.18mm sieve pores is 8.6%, the passing rate of 0.6mm sieve pores is 6.2%, the passing rate of 0.3mm sieve pores is 5.1%, the passing rate of 0.15mm sieve pores is 3.9%, and the passing rate of 0.075mm sieve pores is 2.4%.

The preparation method of the drainage type asphalt mixture comprises the following steps:

s1 asphalt modification treatment: firstly, heating asphalt to a molten state, then adding a rubber modifier, and mixing and stirring the asphalt and the rubber modifier under a heating state of 170 ℃, wherein the stirring speed is 1000rpm, and stirring is carried out for 1min to obtain modified asphalt for later use;

preparing an S2 asphalt mixture: and mixing and stirring the modified asphalt and the aggregate for 70s at the temperature of 180 ℃, adding the filler, and continuously mixing and stirring for 60s to obtain the finished asphalt mixture.

TABLE 1 raw material compounding tables for examples 1 to 5

Examples	Aggregate/kg	Filler/kg	Asphalt/kg	Rubber modifier/kg
					Example 1	130	6	15	7
Example 2	125	5	13	5
					Example 3	120	8	12	6
Example 4	140	9	20	9
					Example 5	150	10	18	10

Example 6

The difference between the embodiment and the embodiment 1 is that the rubber modifier is a mixture of styrene butadiene rubber and nano silica according to the mass ratio of 20: 1.

Example 7

The difference between the embodiment and the embodiment 1 is that the rubber modifier is a mixture of styrene butadiene rubber and nano silica according to the mass ratio of 30: 1.

Example 8

This example differs from example 1 in that the rubber modifier is styrene butadiene rubber.

Example 9

The difference between the embodiment and the embodiment 1 is that the rubber modifier is a mixture of natural rubber and nano silica according to the mass ratio of 24: 1.

Examples 10-20 differ from example 1 in that aggregates were prepared for different preparations, and the corresponding relationship between the aggregates and the preparations in each example is shown in the following table.

TABLE 2 comparative table of aggregate and preparation examples

Examples	10	11	12	13	14	15	16	17	18	19	20
												Preparation example	2	3	4	5	6	7	8	9	10	11	12

Example 21

The difference between this example and example 1 is that in the step of preparing the S2 asphalt mixture, the modified asphalt and the aggregate are mixed and stirred at 180 ℃ for 70S, and then the filler and 1kg of the filtrate preserved in a sealed manner in preparation example 1 are added to continue mixing and stirring for 60S, so as to obtain the finished asphalt mixture.

Example 22

The difference between this example and example 10 is that in the step of preparing the S2 asphalt mixture, the modified asphalt and the aggregate are mixed and stirred at 180 ℃ for 70S, and then the filler and 1kg of the secondary filtrate stored in a sealed manner in preparation example 2 are added to continue mixing and stirring for 60S, so as to obtain the finished asphalt mixture.

Comparative example

Comparative example 1

This comparative example differs from example 1 in that the aggregate was not pretreated by soaking in a polymethylmethacrylate solution.

Comparative example 2

The difference between the comparative example and the example 1 is that the aggregate is not soaked in the polymethyl methacrylate solution for pretreatment, and the aggregate is pretreated by coating the polyurethane waterproof coating on the surface of the aggregate, and the aggregate is naturally dried and then participates in the preparation of the asphalt mixture.

Comparative example 3

This comparative example differs from example 1 in that no rubber modifier is added.

Comparative example 4

An asphalt mixture is prepared by the following steps: the composite material is prepared from the following raw materials in parts by mass: 6kg of high-viscosity modified asphalt, 100kg of basalt and 4kg of limestone mineral powder; the particle size of the basalt is divided into three grades of 5-10 mm, 3-5 mm and 0-3 mm, and the mass ratio of the basalt with the particle size of the three grades is 8: 2: 1;

the preparation method of the high-viscosity modified asphalt comprises the following steps: shearing the mixture of No. 70 matrix asphalt, linear YH-791SBS modifier, sulfur, resin tackifier and rubber oil at 180 +/-5 ℃ for 1h at 5000r/min, and stirring and developing at 180 ℃ for 1.5h to obtain the finished high-viscosity modified asphalt; wherein the No. 70 matrix asphalt comprises 72.7 percent of linear YH-791SBS modifier 8 percent, 0.3 percent of sulfur, 13 percent of resin tackifier and 6 percent of rubber oil by weight.

The preparation method of the asphalt mixture comprises the following steps: and (3) mixing and stirring the high-viscosity modified asphalt and the basalt for 60s at the temperature of 180 ℃, then adding limestone mineral powder, and continuously mixing and stirring for 60s to obtain an asphalt mixture.

Performance detection test method

High temperature stability rut test: the asphalt mixtures of examples 1 to 22 and comparative examples 1 to 4 were tested with reference to the relevant test methods in JTJ052-2000 "road engineering asphalt and asphalt mixture test procedures".

Flying loss test: the asphalt mixtures of examples 1 to 22 and comparative examples 1 to 4 were tested with reference to the relevant method in the kentucker scattering loss test.

And (3) void ratio test: the asphalt mixtures of examples 1 to 22 and comparative examples 1 to 4 were tested with reference to the relevant test methods in JTJ052-2000 road engineering asphalt and asphalt mixture test procedures.

Hydrophobic property test: and manufacturing an asphalt mixture test piece according to the specification, cooling to the specified time, demoulding, and removing the paper on the surface when the test piece is formed. In each example or comparative example, 3 parallel test pieces were prepared, and a test was performed on a rut plate using a road surface water permeability meter, according to the test method of T0971-2008 "determination method of water permeability coefficient of asphalt pavement".

TABLE 3 test data sheet

According to the test data in the table 3 and the detection data of the embodiments 1 to 5 and the comparative examples 1 to 4, the asphalt mixture prepared by the method has good overall structure stability and excellent hydrophobic property. The detection data of the embodiment 1, the comparative example 1 and the comparative example 2 are specifically combined, so that the polymethyl methacrylate solution for soaking the pretreated aggregate has a certain positive significance on the overall structure of the asphalt mixture, the hydrophobic property of the asphalt mixture can be effectively improved, the performance is more excellent compared with that of a polyurethane waterproof coating, and the operation is simpler. In addition, the rubber modifier can effectively improve the viscosity of the asphalt, so that the overall stability of the asphalt mixture is better.

According to the detection data of the embodiment 1 and the embodiment 10, the dimethyl silicone oil and the silane coupling agent are added to carry out secondary soaking on the pretreated aggregate, so that the hydrophobic property of the hydrophobic membrane layer on the surface of the aggregate can be effectively improved, and the method has positive significance on the stability of the overall structure of the asphalt mixture.

In combination with the detection data of example 1, example 10, example 21 and example 22, the addition of the primary filtrate or the secondary filtrate in the preparation process of the asphalt mixture is beneficial to further improving the hydrophobic property and the overall structural stability of the asphalt mixture.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.

Claims

1. The drainage type asphalt mixture is characterized by comprising the following raw materials in parts by mass: 120-150 parts of aggregate, 5-10 parts of filler, 12-20 parts of asphalt and 5-10 parts of rubber modifier, wherein the aggregate is obtained by soaking and pretreating with a polymethyl methacrylate solution.

2. The drainage asphalt mixture according to claim 1, wherein the aggregate is pre-treated by soaking in a polymethyl methacrylate solution, and the method comprises the following steps:

soaking treatment: cleaning aggregate, then soaking the cleaned aggregate in a polymethyl methacrylate solution, hermetically soaking, filtering to obtain a crude product of the pretreated aggregate, and hermetically storing filtrate;

3. The drainage asphalt mixture according to claim 1, wherein the mass concentration of the polymethyl methacrylate solution is 10 g/L-20 g/L.

4. The drainage asphalt mixture according to claim 3, wherein the organic solvent is a mixture of N, N-dimethylformamide and chloroform in a mass ratio of 1 (1.5-3).

5. The drainage type asphalt mixture according to claim 2, wherein the crude pre-treated aggregate obtained in the soaking step is dried after being subjected to secondary soaking treatment, and the specific operations are as follows:

6. The drainage type asphalt mixture according to claim 5, wherein in the secondary soaking treatment step, the mass concentration of the dimethyl silicone oil in the secondary soaking solution is 15 g/L-20 g/L.

7. The drainage type asphalt mixture according to claim 1, wherein the rubber modifier is a mixture of styrene-butadiene rubber and nano silica according to a mass ratio of (20-30): 1.

8. The drainage asphalt mixture according to claim 1, wherein the aggregate and filler are integrally graded as follows:

the passing rate of 19mm sieve pores is 100%, the passing rate of 16mm sieve pores is 90-100%, and the passing rate of 13.2mm sieve pores

The passing rate is 60-80%, the passing rate of 9.5mm sieve pores is 50-60%, the passing rate of 4.75mm sieve pores is 15-23%, the passing rate of 2.36mm sieve pores is 10-20%, the passing rate of 1.18mm sieve pores is 5-14%, the passing rate of 0.6mm sieve pores is 4-12%, the passing rate of 0.3mm sieve pores is 3-10%, the passing rate of 0.15mm sieve pores is 3-8%, and the passing rate of 0.075mm sieve pores is 2-5%.

9. The preparation method of the drainage type asphalt mixture according to any one of claims 1 to 8, which is characterized by comprising the following steps:

and (3) asphalt modification treatment: mixing and stirring the asphalt and the rubber modifier under the heating state to obtain the modification

Asphalt is reserved;

10. The method for preparing a drainage asphalt mixture according to claim 9, wherein in the step of preparing the asphalt mixture, the secondary filtrate is added after the aggregate and the filler are added, and the mixture is mixed and stirred to obtain a finished asphalt mixture.