Solvent type cold-mixed asphalt and preparation method thereof

Abstract

The invention relates to the technical field of road materials, in particular to solvent type cold-mixed asphalt and a preparation method thereof.The solvent type cold-mixed asphalt is prepared from, by weight, 60-75 parts of matrix asphalt, 15-30 parts of diluent, 5-15 parts of modifier, 1-5 parts of tackifier and 1-3 parts of anti-stripping agent; the modifier has a core-shell structure, an inner core is desulfurized rubber powder subjected to oleophylic pretreatment, and a shell layer is a reactive interface layer which is coated on the surface of the inner core and is formed by a silane coupling agent and epoxy resin; by modifying the rubber powder and combining with a preparation process of step-by-step addition, the cold-mixed asphalt can quickly construct a high-strength elastic network skeleton under a normal-temperature construction condition, so that excellent early-stage bearing capacity is obtained; meanwhile, an active shell layer on the surface of the modifier can be chemically bonded with the anti-stripping agent in situ, firm chemical bridging is formed on an asphalt-aggregate interface, and the defects of weak interface bonding and poor water damage resistance are overcome.

Description

Technical Field

[0001] This invention relates to the field of road materials technology, and in particular to solvent-based cold-mix asphalt and its preparation method. Background Technology

[0002] Cold-mix asphalt mixtures offer significant advantages in road maintenance, emergency repairs, and low-temperature construction due to their characteristics such as requiring no high-temperature heating, energy efficiency, environmental friendliness, and ease of construction. Compared to hot-mix asphalt mixtures, their production and paving temperatures are typically between 0°C and 40°C, which can substantially reduce energy consumption and greenhouse gas emissions. However, this technology has long faced two key technical bottlenecks: firstly, the initial strength of the mixture after molding is low, preventing rapid traffic opening; secondly, the strength development period is long, resulting in final road performance often lower than that of hot-mix asphalt mixtures. These shortcomings severely restrict the widespread application of cold-mix asphalt technology in heavy-traffic roads and large-scale projects.

[0003] To improve the performance of cold-mix asphalt, existing technologies mainly focus on binder modification. Common approaches include using emulsified asphalt or adding various modifiers and diluents to the asphalt. Among these, using waste rubber to modify asphalt can improve its elasticity and fatigue resistance, and aligns with the environmental protection concept of resource recycling, making it a research hotspot. However, directly applying rubber powder to cold-mix asphalt systems still presents significant problems: First, the compatibility between rubber powder and asphalt is poor, making it difficult to disperse evenly under normal or medium-low temperature conditions, easily leading to agglomeration, resulting in uneven modification effects, and even affecting workability; second, the interfacial bonding between rubber powder and asphalt is weak, easily becoming a weak link in the mixture under moisture erosion and repeated loading, causing early damage.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the general background of this disclosure and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] This invention provides a solvent-based cold-mix asphalt and its preparation method, which can effectively solve the problems in the background art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of this invention provides a solvent-based cold-mix asphalt, comprising, by weight: 60-75 parts base asphalt, 15-30 parts diluent, 5-15 parts modifier, 1-5 parts tackifier, and 1-3 parts anti-stripping agent; The modifier has a core-shell structure, with the core being desulfurized rubber powder pretreated with oleophilicity, and the shell being a reactive interface layer formed by silane coupling agent and epoxy resin coating the surface of the core.

[0007] This invention solves the performance problems of cold-mix asphalt by using the core-shell structure of the modifier and a step-by-step addition process. First, most of the modifier is added in the high-temperature, high-shear stage. Its core deeply swells, depolymerizes, and strongly interweaves with the asphalt, rapidly constructing a continuous elastic network skeleton. At the same time, the shell layer undergoes thermal cross-linking, chemically anchoring the rubber powder particles in the network, thereby giving the asphalt binder high cohesive strength and elasticity, providing a basis for its high initial strength and resistance to deformation. Subsequently, the remaining modifier is added in the medium-temperature stage. Its core mainly acts as reinforcing particles dispersed in the existing skeleton, and the chemical reactivity of its shell layer is fully preserved, becoming active anchor points. The anti-stripping agent undergoes specific chemical bonding with the above-mentioned active anchor points, forming a reinforced and reactive interface layer on the surface of the modifier particles. The interface layer is distributed throughout the asphalt matrix, which can enhance the adhesion between asphalt and aggregate during subsequent mixing and use, thereby solving the defects of weak interfacial adhesion and poor water damage resistance in cold-mix asphalt mixtures.

[0008] Furthermore, the method for preparing the modifier includes: A1 involves drying the desulfurized rubber powder and then mixing it with 2-4% of a nonionic surfactant and 1-2% of a plasticizer by weight at 70-85°C to form an asphalt-loving layer on the surface of the desulfurized rubber powder. A2 is then added with 0.5-1.5% silane coupling agent and 1-3% low molecular weight epoxy resin by weight of desulfurized rubber powder, and sheared at 90-110℃ to obtain the modifier.

[0009] Furthermore, the nonionic surfactant is at least one of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, and sorbitan fatty acid ester; the plasticizer is at least one of aromatic oil, naphthenic oil, dioctyl phthalate, and dioctyl sebacate; and the low molecular weight epoxy resin is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, and phenolic epoxy resin.

[0010] In step A1, under stirring conditions at 70-85°C, the nonionic surfactant, with its hydrophilic groups, is directionally adsorbed onto the polar sites on the surface of the rubber powder, and its hydrophobic long chains extend outward, forming a molecular-level interface modification layer that significantly reduces the surface energy of the rubber powder. Simultaneously, the plasticizer, under the influence of heat and mechanical force, penetrates and swells the rubber network on the surface of the rubber powder. These two factors work synergistically to form an asphalt-loving layer, guided by a surfactant-oriented monolayer and with swollen rubber and plasticizer as the continuous phases. This improves the wettability and physical compatibility between the rubber powder and asphalt, laying the foundation for the firm adhesion of the subsequent reactive shell layer.

[0011] In step A2, under conditions of heating to 90-110℃ and shearing treatment, some functional groups of the added silane coupling agent hydrolyze to generate silanol groups, which can bind to the surface of the rubber powder or the asphalt-loving layer. Other active groups undergo ring-opening reactions with the epoxy groups of the simultaneously added low-molecular-weight epoxy resin or form an interpenetrating network. This process coats the rubber powder particles with a reactive interfacial layer, i.e., a shell layer, cross-linked by chemical bonds. This enhances the strength of the modifier particles and enriches their surface with active reactive sites such as epoxy groups and silanol groups, improving interfacial adhesion.

[0012] Low molecular weight epoxy resins have the characteristics of low viscosity and good flowability. At the shell construction temperature of 90~110℃, they can more effectively penetrate and wet the asphalt-loving layer formed in A1, thereby achieving uniform and dense coating on the surface of the epoxy powder. High molecular weight epoxy resins have higher viscosity and are difficult to spread and penetrate evenly at this temperature, which can easily lead to uneven coating and affect subsequent performance.

[0013] Furthermore, the diluent is at least one of vegetable oil derivatives, biodiesel, and bio-based solvent oil.

[0014] During the preparation process, the diluent first reduces the viscosity of high-temperature asphalt, allowing the modifier, tackifier, and other components to be evenly dispersed. During construction, it lowers the viscosity required for mixing and paving the mixture, enabling operation at room temperature or low temperature. After the mixture has set, the diluent can gradually volatilize or participate in the physicochemical processes within the system, promoting the recovery and enhancement of the asphalt binder's adhesive properties.

[0015] Furthermore, the base asphalt is 70# petroleum asphalt, with a penetration of 50~70mm at 25℃, a softening point of 45~55℃, and a ductility of >100cm at 15℃.

[0016] The aforementioned penetration ensures that the asphalt has suitable fluidity after heating, facilitating the uniform dispersion of subsequent components; the aforementioned softening point balances the stability at room temperature storage with the energy consumption of heating during construction; and the aforementioned ductility gives the matrix sufficient flexibility, providing reliable support for the modified network.

[0017] Furthermore, the tackifier is at least one of styrene-butadiene-styrene block copolymer, styrene-butadiene rubber, and ethylene-vinyl acetate copolymer.

[0018] During the premixing and step-by-step incorporation stages, the thickener can effectively compensate for the system viscosity that may be lost due to the addition of the diluent, and work synergistically with the elastic network formed by the modifier to improve the working viscosity of cold-mix asphalt during the construction period.

[0019] Furthermore, the anti-stripping agent is at least one of polyamide, aminosilane, and epoxysilane.

[0020] The active functional groups in the molecular structure of the aforementioned substances can undergo covalent bonding reactions with the epoxy groups, silanol groups, and other sites enriched on the surface of the modifier shell, allowing the modifier particles to be firmly integrated into the asphalt matrix through chemical bonds, thus strengthening the interface. Simultaneously, some groups in the aforementioned anti-stripping agent can also form chemical adsorption or bonding with the surface of subsequently added aggregates. This constructs a stable chemical bridge at the asphalt-modifier-aggregate multiphase interface, thereby enhancing the mixture's ability to resist the loss of adhesion caused by water erosion.

[0021] A second aspect of the present invention provides a method for preparing the above-mentioned solvent-based cold-mix asphalt, comprising: S1 heats the base asphalt to 160~180℃ to obtain flowing asphalt; S2 involves adding 60-70% of the modifier to the flowing asphalt, stirring at 175-180℃ and 4000-5000 r / min, and then maintaining the temperature at 170-180℃ for development. In this step, the high temperature and high shear force promote the deep swelling and dispersion of the modifier core, which intertwines with the asphalt molecules. At the same time, the shell undergoes a thermal cross-linking reaction, chemically anchoring the rubber powder particles in the asphalt matrix to form an initial continuous elastic network structure. The heat preservation and development stabilizes this network structure.

[0022] S3. Cool the product from step S2 to 120~140℃, add the remaining modifier, and stir at 1000~1500 r / min. In this step, by reducing the temperature and shear force, the integrity of the modifier shell structure and its chemical reactivity are protected, so that it is dispersed in the formed network in the form of enhanced particles with active sites, providing active anchors for subsequent interfacial chemical bonding.

[0023] S4. 45-55% of the diluent is premixed with the tackifier at 55-65°C to obtain a premixed liquid. This step allows the tackifier to fully swell or dissolve in the diluent, forming a uniform premixed liquid with low viscosity, so that it can be quickly and evenly dispersed into the asphalt system when subsequently incorporated.

[0024] In step S5, the premixed liquid is added in batches to the product obtained in step S3, and stirred and mixed at 95~105℃. Then, the anti-stripping agent is added, and after stirring, the remaining diluent is added, stirred, and then sealed and cured to obtain the final product. In this step, the premixed liquid is added in batches and stirred and mixed at 95~105℃ to ensure that the thickener is evenly dispersed and the system viscosity is adjusted. Subsequently, the anti-stripping agent is added to ensure that it fully contacts and chemically bonds with the active shell layer reserved on the surface of the modifier under the condition that the system viscosity is relatively high and the molecular motion is still relatively active. Finally, the remaining diluent is added to adjust the overall viscosity of the system to a suitable application range. Sealing and curing further homogenizes the components in the system and completes the residual reaction.

[0025] Furthermore, the maturation time is 22-30 hours.

[0026] During the aforementioned period, the diluent components achieve a more uniform distribution through molecular diffusion, the chemical bonding reaction between the anti-stripping agent and the modifier shell is fully carried out, and the local stress generated by high-speed shear within the system is released.

[0027] Furthermore, the premixing temperature is 55~65℃, and the time is 5~20min.

[0028] The above-mentioned temperature and time allow the thickener to fully swell and disperse in the diluent, forming a homogeneous premix. Too low a temperature will result in uneven dispersion of the thickener, while too high a temperature may cause component volatilization or thermal aging.

[0029] The technical solution of this invention achieves the following technical effects: By using a modifier with an oleophilic core and a reactive shell, and employing a matching stepwise sequential preparation process, this invention effectively solves the problems of low initial strength and weak long-term interfacial adhesion in cold-mix asphalt through synergistic effects on both material and process levels. The modifier core, activated during the high-temperature, high-shear stage, constructs a continuous elastic skeleton, while its thermally cross-linked shell anchors the particles within it, providing a physical basis for high initial strength and deformation resistance. Meanwhile, the modifier, which retains the shell activity completely during the intermediate-temperature stage, acts as a chemical anchor point, bonding in situ with the anti-stripping agent, strengthening the asphalt-aggregate interface, and giving it excellent resistance to water damage and long-term durability. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic flowchart of the solvent-based cold-mix asphalt preparation method of the present invention. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0034] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application.

[0035] Example 1: This embodiment provides a method for preparing solvent-based cold-mix asphalt, and the types, proportions, and process parameters of the raw materials used are as follows: Raw material preparation and pretreatment Base asphalt: 70# road petroleum asphalt, 70 parts, penetration at 25℃ is 60mm, softening point is 50℃, ductility at 15℃ is greater than 150cm; Diluent: Industrial grade biodiesel, 20 parts; Tackifier: Styrene-butadiene-styrene block copolymer, 3 parts; Anti-stripping agent: Polyamide, 2 parts; Modifier: 15 parts, the preparation process of the modifier is as follows: A1. Desulfurized rubber powder with an average particle size of 40 mesh was dried at 105℃ until the moisture content was below 0.5%. 1000g of the dried desulfurized rubber powder was added to a reactor, along with 3% by weight of alkylphenol polyoxyethylene ether as a nonionic surfactant and 1.5% by weight of aromatic oil as a plasticizer. The mixture was stirred at 75℃ and 500r / min for 40 minutes to form a uniform asphalt-loving layer on the surface of the rubber powder.

[0036] Subsequently, 1.0% KH-550 (by mass of the desulfurized rubber powder) and 2% bisphenol A type low molecular weight epoxy resin (with an epoxy value of 0.48-0.54) were added to the system. The temperature was raised to 100℃, and the stirring speed was increased to 4000 r / min. Shear treatment was continued for 20 minutes to allow the silane coupling agent and epoxy resin to react and coat the surface of the rubber powder, forming a reactive shell layer. The modifier was then cooled and stored for later use.

[0037] The preparation method of solvent-based cold-mix asphalt is as follows: S1 adds 70 parts of base bitumen into a mixing tank, heats it to 170°C, and maintains this temperature to make it a homogeneous flowing liquid.

[0038] S2 added 9 parts of modifier to the flowing asphalt, raised the system temperature to 178℃, and stirred for 60 minutes under high-speed shear at 4500 r / min. Then, it was kept at a constant temperature of 178℃ and allowed to stand for 30 minutes to develop.

[0039] S3. Cool the product obtained in S2 to 130℃ and add the remaining 6 parts of modifier. Adjust the stirring speed to 1200 r / min and continue stirring for 25 minutes.

[0040] S4 took 11 parts of biodiesel and all 3 parts of thickener, premixed them in a container at 60°C, and stirred at 300 r / min for 12 minutes to obtain a homogeneous premix.

[0041] S5: The premixed liquid obtained in S4 is slowly added to the product of S3 in three portions. During the addition process, the system temperature is maintained at 100℃ and the mixture is stirred at a speed of 800r / min. After all the premixed liquid has been added and mixed evenly, 2 parts of polyamide anti-stripping agent are added and stirred for 15 minutes under the same conditions. Then, the remaining 9 parts of biodiesel are added and stirred for another 10 minutes until uniform. Heating is stopped, and the mixture is transferred to a sealed container and allowed to stand at room temperature for 24 hours to mature, thus obtaining the solvent-based cold-mix asphalt product.

[0042] Example 2: This embodiment provides a method for preparing solvent-based cold-mix asphalt, and the types, proportions, and process parameters of the raw materials used are as follows: Raw material preparation and pretreatment Base asphalt: 70# road petroleum asphalt, 65 parts, penetration at 25℃ is 55mm, softening point is 52℃, ductility at 15℃ is greater than 120cm; diluent: soybean oil derivative, 18 parts; tackifier: styrene-butadiene rubber, grade 1502, 4 parts; anti-stripping agent: aminosilane, 2 parts; modifier: 12 parts. The preparation process of the modifier is as follows: A1. Desulfurized rubber powder with an average particle size of 60 mesh was dried at 115℃ until the moisture content was below 0.5%. 1000g of the dried desulfurized rubber powder was added to a reactor, along with 2.5% by weight of fatty alcohol polyoxyethylene ether as a nonionic surfactant and 1% by weight of naphthenic oil as a plasticizer. The mixture was stirred at 80℃ and 600 rpm for 40 minutes to form a uniform asphalt-loving layer on the surface of the rubber powder.

[0043] A2 Subsequently, 0.8% KH-560 (by mass of the desulfurized rubber powder) and 1.5% bisphenol F type low molecular weight epoxy resin were added to the system. The temperature was raised to 95℃, and the stirring speed was increased to 3800 r / min. The mixture was continuously sheared for 20 minutes to allow the silane coupling agent and epoxy resin to react and coat the surface of the rubber powder, forming a reactive shell layer. The modifier was then cooled and set aside for later use.

[0044] The preparation method of solvent-based cold-mix asphalt is as follows: S1 adds 65 parts of base bitumen into a mixing tank, heats it to 165°C, and maintains this temperature to make it a homogeneous flowing liquid.

[0045] S2 adds 8 parts of modifier to the flowing asphalt, raises the system temperature to 175℃, and stirs for 60 minutes under high-speed shear at 4000 r / min. Then, it is kept at a constant temperature of 175℃ and allowed to stand for 35 minutes to develop.

[0046] S3. Cool the product obtained in S2 to 125℃ and add the remaining 4 parts of modifier. Adjust the stirring speed to 1100 r / min and stir continuously for 25 minutes.

[0047] S4 Take 10 parts of soybean oil derivative and all 3 parts of thickener, premix them in a container at 60°C, and stir at 300 r / min for 12 minutes to obtain a homogeneous premix.

[0048] S5: The premixed liquid obtained in S4 is slowly added to the product of S3 in three portions. During the addition process, the system temperature is maintained at 98℃ and the mixture is stirred at a speed of 700r / min. After all the premixed liquid has been added and mixed evenly, 2 parts of aminosilane anti-stripping agent are added and stirred for 15 minutes under the same conditions. Then, the remaining 8 parts of soybean oil derivative are added and stirred for another 10 minutes until uniform. Heating is stopped, and the mixture is transferred to a sealed container and allowed to stand at room temperature for 26 hours to mature, thus obtaining the solvent-based cold-mix asphalt product.

[0049] Example 3: Unlike Example 1, the modifier was prepared using the following method: A1: Take desulfurized rubber powder with an average particle size of 40 mesh and dry it at 110℃ until the moisture content is less than 0.5%. Add 1000g of the dried desulfurized rubber powder to a reactor, add 2.0% by weight of fatty acid polyoxyethylene ester as a nonionic surfactant, and 2% by weight of dioctyl sebacate as a plasticizer. Stir at 72℃ and 550r / min for 45 minutes to form a uniform asphalt-loving layer on the surface of the rubber powder.

[0050] A2: Subsequently, 1.5% KH-792 (by mass of the desulfurized rubber powder) and 3% phenolic epoxy resin (F-51) were added to the system. The temperature was raised to 105℃, and the stirring speed was increased to 4200 r / min. The mixture was continuously sheared for 18 minutes to allow the silane coupling agent and epoxy resin to react and coat the surface of the rubber powder, forming a reactive shell layer. The modifier was then cooled and set aside for later use.

[0051] Comparative Example 1: The difference between this comparative example and Example 1 is that the preparation of the modifier only involves a simple surface activation treatment of the desulfurized rubber powder. Specifically, after drying desulfurized rubber powder of the same mesh size, it is stirred at 75°C for 40 minutes with 3% (by weight) alkylphenol polyoxyethylene ether.

[0052] Comparative Example 2: The difference between this comparative example and Example 1 is that the modifier was prepared by only step A1, and not step A2.

[0053] Comparative Example 3: In step A2 of the modifier preparation, the same mass of high molecular weight bisphenol A type solid epoxy resin (epoxy value of approximately 0.3 eq / 100g) is used to replace the low molecular weight epoxy resin.

[0054] Comparative Example 4: The difference between this comparative example and Example 1 is that, in the preparation of solvent-based cold-mix asphalt, the stepwise addition process is not used, and all 15 parts of modifier are added at once in step S2.

[0055] The solvent-based cold-mix asphalt prepared in each embodiment and comparative example was mixed with AC-13 graded limestone aggregate at room temperature and compacted to obtain cold-mix asphalt mixture specimens. The solvent-based cold-mix asphalt accounted for 5.2% of the aggregate mass. The above specimens were subjected to the following tests, and the results are shown in Table 1: After curing at 25℃ for 1 hour and 24 hours, Marshall tests were immediately carried out to determine the failure load and obtain the Marshall stability (kN). For each example and comparative example, one set of specimens was immersed in a 60℃ water bath for 30-40 minutes to measure stability MS1; another set of specimens was immersed in a 60℃ water bath for 48 hours to measure stability MS2; the water immersion residual stability ratio was calculated according to the formula MS2 / MS1×100%. The specimen was kept at -10℃ and subjected to a three-point bending test. The maximum bending tensile strain at failure was measured to obtain the low-temperature bending strain (με).

[0056] Table 1. Test results of the examples and comparative examples. As shown in the table above, all examples exhibited high performance, verifying the synergistic effect of the core-shell structure and the stepwise addition process: the deep dispersion and swelling of the modifier core constructed a continuous network, and the thermal cross-linking of its reactive shell at high temperature anchored the particles within it, jointly providing a solid early mechanical framework. In contrast, the modifier structures of Comparative Examples 1-3 were incomplete, and the one-time addition process in Comparative Example 4 resulted in poor network construction and a significant reduction in early strength, leading to Marshall stability far lower than that of the examples. Comparative Examples 1 and 2 lacked effective shells, the shell reactivity of Comparative Example 3 was insufficient, and the addition process in Comparative Example 4 resulted in inadequate bonding, leading to a significant decrease in residual stability ratios.

[0057] Examples 1-3 exhibit high strain values, achieving high strength without sacrificing flexibility. This is attributed to the good dispersibility provided by the oleophilic core, which avoids stress concentration, and the toughening effect of the modifier that partially retains the intact particle morphology during the stepwise process. The low-temperature strains of the comparative examples are generally lower due to weak interfacial bonding, uneven dispersion, or increased material brittleness.

[0058] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of the application as defined herein, and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. A solvent-based cold-mix asphalt, characterized in that, By weight, including: 60-75 parts base asphalt, 15-30 parts diluent, 5-15 parts modifier, 1-5 parts tackifier, and 1-3 parts anti-stripping agent; The modifier has a core-shell structure, with the core being a desulfurized rubber powder pretreated with oleophilicity and the shell being a reactive interface layer formed by a silane coupling agent and an epoxy resin coating the surface of the core.

2. The solvent-based cold-mix asphalt according to claim 1, characterized in that, The method for preparing the modifier includes: After drying the desulfurized rubber powder, it is mixed with 2-4% of nonionic surfactant and 1-2% of plasticizer by weight of the desulfurized rubber powder at 70-85℃ to form an asphalt-loving layer on the surface of the desulfurized rubber powder. Then, 0.5-1.5% of silane coupling agent and 1-3% of low molecular weight epoxy resin are added according to the mass of desulfurized rubber powder, and shearing is performed at 90-110℃ to obtain the modifier.

3. The solvent-based cold-mix asphalt according to claim 2, characterized in that, The nonionic surfactant is at least one of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, and sorbitan fatty acid ester; the plasticizer is at least one of aromatic oil, naphthenic oil, dioctyl phthalate, and dioctyl sebacate; and the low molecular weight epoxy resin is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, and phenolic epoxy resin.

4. The solvent-based cold-mix asphalt according to claim 1, characterized in that, The diluent is at least one of vegetable oil derivatives, biodiesel, and bio-based solvent oils.

5. The solvent-based cold-mix asphalt according to claim 1, characterized in that, The base asphalt is 70# petroleum asphalt, with a penetration of 50~70mm at 25℃, a softening point of 45~55℃, and an ductility of >100cm at 15℃.

6. The solvent-based cold-mix asphalt according to claim 1, characterized in that, The tackifier is at least one of styrene-butadiene-styrene block copolymer, styrene-butadiene rubber, and ethylene-vinyl acetate copolymer.

7. The solvent-based cold-mix asphalt according to claim 1, characterized in that, The anti-stripping agent is at least one of polyamide, aminosilane, and epoxysilane.

8. The method for preparing solvent-based cold-mix asphalt according to any one of claims 1 to 7, characterized in that, include: S1 heats the base asphalt to 160~180℃ to obtain flowing asphalt; S2 adds 60-70% of the modifier to the flowing asphalt, stirs at 175-180℃ and 4000-5000 r / min, and then keeps warm at 170-180℃ for development; S3. Cool the product from step S2 to 120~140℃, add the remaining modifier, and stir at 1000~1500 r / min; S4. 45-55% of the diluent is premixed with the thickener at 55-65°C to obtain a premixed solution; S5. The premixed liquid is added in batches to the product obtained in step S3 and stirred and mixed at 95~105℃; then the anti-stripping agent is added, and after mixing, the remaining diluent is added, and after mixing, it is sealed and cured to obtain the final product.

9. The method for preparing solvent-based cold-mix asphalt according to claim 8, characterized in that, The ripening time is 22-30 hours.

10. The method for preparing solvent-based cold-mix asphalt according to claim 8, characterized in that, The premixing temperature is 55~65℃, and the time is 5~20min.

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