Nano-composite high-viscosity and high-stability modified asphalt and preparation method thereof

Abstract

The invention discloses nano-composite high-viscosity and high-stability modified asphalt and a preparation method thereof, and belongs to the technical field of road engineering materials. The modified asphalt is prepared from the following raw materials in parts by weight: 100 parts of matrix asphalt, 3 to 10 parts of star-shaped SBS (Styrene Butadiene Styrene), 5 to 25 parts of waste tire rubber powder, 2 to 6 parts of C5 / C9 petroleum resin, 2 to 8 parts of naphthenic oil, 0.1 to 0.5 part of sulfur, 1 to 3 parts of organic montmorillonite, and 0.5 to 2 parts of optional maleic anhydride grafted polypropylene and / or 0.1 to 0.5 part of silane coupling agent. The core of the preparation method is that through a three-stage process of swelling and nano dispersion, development and interface reaction and cross-linking stabilization, the technical problems of poor compatibility and easy segregation of an SBS / rubber powder composite system are fundamentally solved by utilizing the physical barrier effect of a nano sheet layer and the synergistic effect of vulcanization / interface chemical bonding. The obtained product has ultrahigh viscosity (dynamic viscosity gt at 60 DEG C, 80000 Pa.s), excellent storage stability (segregation error 1t at 48 hours, 2.0 DEG C) and excellent aging resistance, and the comprehensive performance of the product is far better than that of the prior art.

Description

Technical Field

[0001] This invention relates to the field of road engineering materials technology, specifically to a nanocomposite high-viscosity, high-stability modified asphalt and its preparation method. Background Technology

[0002] High-viscosity modified asphalt is a core material for constructing drainage and noise-reducing pavements, steel bridge decks, and heavy-duty traffic roads. To achieve both high performance and low cost, the industry often uses SBS (styrene-butadiene-styrene block copolymer) and waste tire rubber powder (CR) for composite modification. However, SBS and CR differ significantly in chemical structure and polarity, resulting in poor compatibility in asphalt. Modified asphalt produced by simple physical blending is highly susceptible to phase separation (segregation) during thermal storage, leading to severely uneven performance—a fatal flaw hindering the widespread adoption of this technology.

[0003] Existing technologies, such as CN105585854B, disclose a high-viscosity asphalt that is easy to apply. This asphalt utilizes polyphosphoric acid chemical modification, a specific composite viscosity modifier (mesoporous molecular sieves coated with epoxy-grafted polyethylene wax), and higher fatty alcohols to balance high and low temperature performance and application viscosity. While this technology improves workability by adsorbing moisture through mesoporous molecular sieves and releasing it during application to reduce viscosity, its core approach relies on "warm mixing" to reduce high-temperature viscosity, failing to fundamentally address the inherent poor thermal storage stability of the SBS / CR multiphase polymer composite system. The composite viscosity modifier's mechanism of action is physical adsorption and release, rather than improving the compatibility of the multiphase interface. Furthermore, other existing technologies (such as CN103819918A) primarily improve compatibility by optimizing the SBS / CR ratio or adding simple compatibilizers, but with limited effectiveness. Another technology (such as CN103073748A) introduces sulfur to crosslink SBS. Although this can improve the stability of a single SBS system, for complex SBS / CR composite systems, simple sulfurization is difficult to perfectly bridge the interface between the two phases, and there is a bottleneck in improving the viscosity of the system.

[0004] Therefore, there is an urgent need in this field for a new technical solution that can fundamentally resolve the contradiction between high viscosity, high stability, and excellent comprehensive road performance. Summary of the Invention

[0005] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide a nanocomposite high-viscosity, high-stability modified asphalt and its preparation method. To solve the above technical problem, the basic concept of the technical solution adopted by this invention is as follows:

[0006] A nanocomposite high-viscosity, high-stability modified asphalt comprises the following raw materials in parts by weight: 100 parts base asphalt; 3-10 parts star-shaped styrene-butadiene-styrene block copolymer; 5-25 parts 40-80 mesh waste tire rubber powder; 2-6 parts C5 / C9 copolymer petroleum resin with a softening point of 90-120℃; 2-8 parts naphthenic oil; 0.1-0.5 parts sulfur; and 1-3 parts organo-modified montmorillonite.

[0007] Furthermore, it also contains 0.5-2 parts of maleic anhydride-grafted polypropylene.

[0008] Adding PP-g-MAH as a reactive compatibilizer enables crucial interfacial chemical bridging. Specifically, it significantly improves low-temperature crack resistance: comparing Example 1 (without PP-g-MAH) and Example 2 (with PP-g-MAH), the ductility at 5°C increased from 35.2 cm to 41.5 cm, an increase of approximately 18%. This indicates that the chemical bonds formed by PP-g-MAH at the SBS-powder interface effectively transfer and disperse stress, greatly improving the low-temperature toughness of the material. Furthermore, it further optimizes storage stability: the 48-hour segregation softening point difference in Example 2 was 1.4°C, superior to 1.7°C in Example 1, demonstrating that stronger interfacial bonding further suppresses the tendency for polymer phase separation.

[0009] Furthermore, it also contains 0.1-0.5 parts of silane coupling agent.

[0010] Based on the above, further compounding with silane coupling agents can form a dual interface modification mechanism, producing the following synergistic effects: significantly enhanced anti-aging performance. The residual penetration ratio (79%, 83%) and ductility at 5°C after RTFOT (28.9 cm, 35.8 cm) of Examples 3 and 4 (containing Si-69) were significantly higher than those of Example 1 without Si-69. This indicates that Si-69 participates in and strengthens the crosslinking network, enabling it to maintain excellent performance after thermo-oxidative aging. Synergistically improved overall performance. The various properties of Example 4 (containing both PP-g-MAH and Si-69) reached the best, indicating that the dual interface modifier produced a good synergistic effect.

[0011] Furthermore, the silane coupling agent is bis-(3-triethoxysilylpropyl)tetrasulfide.

[0012] The preferred silane coupling agent is bis-(3-triethoxysilylpropyl)tetrasulfide (commercially known as Si-69) because of its high crosslinking ability and excellent coupling effect.

[0013] Furthermore, the styrene / butadiene block ratio of the star-shaped styrene-butadiene-styrene block copolymer is 30 / 70.

[0014] This limitation optimizes the microstructure of SBS, and this specific block ratio has the following advantages: the 30 / 70 S / B ratio provides the best balance of hardness and strength (provided by the polystyrene phase) and elasticity and flexibility (provided by the polybutadiene phase) in asphalt modification, which is the molecular basis for obtaining high softening point, high viscosity, and good low-temperature ductility and elastic recovery (as shown in all examples); and this ratio of star-shaped SBS is more likely to form a moderately sized and stable physical crosslinked network, providing an ideal basic framework for subsequent nanocompositing and chemical crosslinking.

[0015] Furthermore, the waste tire rubber powder is desulfurized rubber powder that has undergone activation treatment.

[0016] Activation treatments (such as mechanochemical or surface grafting) increase the active groups (such as hydroxyl and carboxyl groups) on the surface of the rubber powder, making it easier for it to undergo interfacial chemical reactions with the anhydride groups and silane coupling agents of PP-g-MAH, rather than simple physical coating. Furthermore, the desulfurization treatment partially breaks down the original dense cross-linked network of the rubber powder, making it easier to swell and disperse under high-temperature shear. This allows it to more fully integrate into the new cross-linked network constructed from SBS and sulfur, becoming an organic component of the network rather than an isolated defect.

[0017] Furthermore, the aromatic content of the naphthenic oil is less than 10%.

[0018] Low-aromatic naphthenic oils are preferred because they are not only safer and more environmentally friendly, but also have excellent aging resistance and balanced compatibility.

[0019] Furthermore, the sulfur is insoluble sulfur.

[0020] Insoluble sulfur not only offers high processing safety—at preparation temperatures (<180℃), it exists stably as dispersed particles, greatly reducing the risk of "scorching" caused by sulfur volatilization and premature reaction during processing, thus ensuring the stability and safety of the production process—but also boasts high cross-linking efficiency: during subsequent stirring and development, insoluble sulfur can be uniformly dispersed and enriched at the interface, ultimately transforming into soluble sulfur for cross-linking, ensuring the uniformity and efficiency of the cross-linking reaction.

[0021] Furthermore, its dynamic viscosity at 60℃ is not less than 80,000 Pa·s, and the difference in segregation softening point after 48 hours does not exceed 2.0℃.

[0022] A method for preparing nanocomposite high-viscosity, high-stability modified asphalt includes the following steps:

[0023] (1) Swelling and nano-dispersion stage: Heat the base asphalt to 165-175℃, and add star-shaped styrene-butadiene-styrene block copolymer, naphthenic oil and organo-modified montmorillonite in sequence at a speed of 2000-3000 rpm. Maintain this temperature and shear conditions for 45-60 minutes.

[0024] (2) Development and interface reaction stage: Heat the mixture obtained in step (1) to 175-185℃, add waste tire rubber powder, C5 / C9 copolymer petroleum resin, and optional maleic anhydride grafted polypropylene and / or silane coupling agent, increase the rotation speed to 4500-5500 rpm, and perform high-speed shear development for 75-105 minutes.

[0025] (3) Crosslinking stabilization stage: Cool the mixture obtained in step (2) to 168-172℃, add sulfur, reduce the rotation speed to 300-500 rpm, and stir at low speed for 25-35 minutes to obtain the nanocomposite high viscosity and high stability modified asphalt. In step (3), it is crucial to accurately control the crosslinking stage temperature at 168-172℃. This specific temperature range ensures efficient crosslinking of sulfur while minimizing severe thermal aging of the asphalt.

[0026] It should be noted that a key aspect of this invention lies in the fact that, through a specific "swelling and nanodispersion" process, under suitable shear force and temperature, organo-modified montmorillonite achieves nanoscale exfoliation and dispersion within an asphalt-polymer matrix, forming nanosheets with enormous specific surface area and aspect ratio. These uniformly dispersed nanosheets, on the one hand, significantly enhance the polymer network through physical cross-linking points, contributing to the ultra-high viscosity; on the other hand, their nanoscale barrier effect effectively hinders the chain segment movement and macroscopic migration of polymer molecules, which is the core reason for achieving exceptional storage stability.

[0027] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art.

[0028] This invention fundamentally solves industry challenges by constructing a multi-layered synergistic stabilizing system. Unlike existing technologies (such as CN105585854B) that use mesoporous molecular sieves to adsorb moisture for "warm mixing and viscosity reduction," this invention's core lies in its unique component design and three-stage preparation process, successfully constructing a multi-layered synergistic stabilizing system of "nanophysical barrier - sulfurization chemical crosslinking - interfacial chemical bonding." This system fundamentally alters the phase structure of SBS / rubber powder composites, rather than physically modifying them, thus achieving technological innovation and delivering the following superior properties:

[0029] Achieving a balance between high viscosity and high stability, resulting in a significant performance improvement: As shown in Table 1, the synergistic effect of the nano-reinforcing effect of organic montmorillonite (OMMT) and the sulfur crosslinking network is key to achieving both high viscosity and high stability. The dynamic viscosity at 60°C of Example 1 (basic nanocomposite system) reached 88,500 Pa·s, far exceeding the performance of Comparative Example 2 (sulfur crosslinking only, 62,300 Pa·s) and Comparative Example 3 (OMMT only, 40,100 Pa·s). The improvement far exceeds the simple sum of the effects of the two, demonstrating a significant synergistic reinforcing effect. Simultaneously, this synergistic network kept the 48-hour segregation softening point difference stably controlled within 2.0°C (1.7°C in Example 1), fundamentally solving the storage segregation problem of SBS / rubber powder composite modified asphalt.

[0030] Interfacial chemical modification ensures balanced high and low temperature performance, breaking through performance bottlenecks: This invention achieves chemical bonding at the interface between SBS and the asphalt powder by introducing maleic anhydride-grafted polypropylene (PP-g-MAH) and a silane coupling agent. As shown in Table 1, the ductility at 5°C of Example 2 (with added PP-g-MAH) reached 41.5 cm, an improvement of approximately 18% compared to Example 1 (35.2 cm), demonstrating the contribution of interfacial strengthening to the low-temperature toughness of the material. Therefore, this invention successfully overcomes the technical bottleneck of low-temperature performance degradation often associated with high-viscosity asphalt while achieving high viscosity (>80,000 Pa·s) and softening point (>96°C), achieving an excellent balance between high and low temperature performance.

[0031] The nanocomposite structure imparts superior durability and extends service life: the uniformly dispersed OMMT nanosheets have a significant physical barrier effect on the diffusion of oxygen and ultraviolet light, thereby greatly delaying the aging process of asphalt. The residual penetration ratio (78%-83%) and ductility at 5°C (26.8-35.8 cm) of Examples 1-4 after RTFOT were significantly higher than those of all comparative examples, demonstrating that the "nano-chemical" synergistic network has excellent anti-aging ability, indicating that the product of this invention has a longer service life.

[0032] Maintaining excellent workability while achieving ultra-high performance facilitates engineering applications: Although the product of this invention has an extremely high viscosity at 60°C, its Brinell viscosity at 135°C can still be controlled below 3.2 Pa·s (see Table 1). This viscosity range ensures good pumping, mixing, and paving performance under normal construction temperatures. This demonstrates that the invention achieves ultra-high performance without sacrificing ease of construction, and has promising prospects for engineering applications.

[0033] The specific embodiments of the present invention will be described in further detail below. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0035] The experimental materials involved in this invention include: base asphalt: SK-70# road petroleum asphalt; star-shaped SBS: YH-791 (Sinopec Yueyang Petrochemical), S / B=30 / 70; waste tire rubber powder: 40 mesh, desulfurized rubber powder with surface activation treatment; C5 / C9 petroleum resin: CKR-120 (softening point 120℃), Ningbo Yonghua Resin; naphthenic oil: KN4010 (aromatic content <8%), Karamay Petrochemical; sulfur: insoluble sulfur IS-60, Shanghai Jinghua Chemical; organic montmorillonite (OMMT): DK4 type, Zhejiang Fenghong New Materials; maleic anhydride grafted polypropylene (PP-g-MAH): CMG9801, Shanghai Rizhisheng; silane coupling agent: Si-69, Nanjing Chengong Organosilicon.

[0036] Example 1

[0037] First, weigh 5000 g (100 parts by weight) of base bitumen into a 10-liter reactor equipped with stirring and heating functions, and heat it to 170°C until it is completely molten and flowing. Then, proceed with the following steps in sequence: Step (1) Swelling and Nanodispersion: Start stirring and control the speed at 2500 rpm. Add 300 g (6 parts) of star-shaped SBS, 300 g (6 parts) of naphthenic oil, and 100 g (2 parts) of organo-modified montmorillonite to the reactor in sequence. Maintain the temperature inside the reactor at 170±2°C and continue high-speed shearing for 50 minutes. Step (2) Development and Interface Reaction: Raise the temperature of the reactor to 180°C. Add 750 g (15 parts) of waste tire rubber powder and 200 g (4 parts) of C5 / C9 petroleum resin to the system. Increase the stirring speed to 5000 rpm and carry out high-speed shear development for 90 minutes under these conditions. Step (3) Crosslinking Stabilization: Lower the temperature of the reactor to 170°C. Reduce the stirring speed to 400 rpm. Add 15 g (0.3 parts) of sulfur to the system and react for 30 minutes under this low-speed stirring condition. After the reaction is complete, discharge the material to obtain the high-viscosity, high-stability nanocomposite modified asphalt described in this invention. Its performance test results are shown in Table 1.

[0038] Example 2

[0039] The preparation method and steps of Example 1 are the same, except that the raw material ratio and the components added in step (2) are different. Specifically, the raw material ratio in Example 2 is as follows: 5000 g (100 parts) of base asphalt; 300 g (6 parts) of star-shaped SBS; 750 g (15 parts) of waste tire rubber powder; 200 g (4 parts) of C5 / C9 petroleum resin; 300 g (6 parts) of naphthenic oil; 100 g (2 parts) of organo-modified montmorillonite; 50 g (1 part) of PP-g-MAH; and 15 g (0.3 parts) of sulfur. In step (2), PP-g-MAH is added at the same time as the rubber powder and petroleum resin. The remaining steps and process parameters are exactly the same as in Example 1. The performance of the obtained product is shown in Table 1.

[0040] Example 3

[0041] The preparation method and steps of Example 1 are the same, except that the raw material ratio and the components added in step (2) are different. Specifically, the raw material ratio in Example 3 is as follows: 5000g (100 parts) of base asphalt; 300g (6 parts) of star-shaped SBS; 750g (15 parts) of waste tire rubber powder; 200g (4 parts) of C5 / C9 petroleum resin; 300g (6 parts) of naphthenic oil; 100g (2 parts) of organo-modified montmorillonite; 25g (0.5 parts) of silane coupling agent Si-69; and 15g (0.3 parts) of sulfur. In step (2), silane coupling agent Si-69 is added at the same time as the rubber powder and petroleum resin. The remaining steps and process parameters are exactly the same as in Example 1. The performance of the obtained product is shown in Table 1.

[0042] Example 4

[0043] The preparation method and steps of Example 1 are the same, except that the raw material ratio and the components added in step (2) are different. Specifically, the raw material ratio in Example 4 is as follows: 5000 g (100 parts) of base asphalt; 300 g (6 parts) of star-shaped SBS; 750 g (15 parts) of waste tire rubber powder; 200 g (4 parts) of C5 / C9 petroleum resin; 300 g (6 parts) of naphthenic oil; 100 g (2 parts) of organo-modified montmorillonite; 50 g (1 part) of PP-g-MAH; 25 g (0.5 parts) of silane coupling agent Si-69; and 15 g (0.3 parts) of sulfur. In step (2), PP-g-MAH and silane coupling agent Si-69 are added at the same time as the rubber powder and petroleum resin. The remaining steps and process parameters are exactly the same as in Example 1. The performance of the obtained product is shown in Table 1.

[0044] Comparative Example 1

[0045] The preparation method and steps of Example 1 were followed, except that sulfur and organic montmorillonite were not added. Specifically, the raw material composition in Comparative Example 1 was as follows: 5000 g (100 parts) of base bitumen; 300 g (6 parts) of star-shaped SBS; 750 g (15 parts) of waste tire rubber powder; 200 g (4 parts) of C5 / C9 petroleum resin; and 300 g (6 parts) of naphthenic oil. In the preparation process, only SBS and naphthenic oil were added in step (1); step (3) was not performed, and the remaining parameters were the same as in Example 1. The performance of the obtained product is shown in Table 1.

[0046] Comparative Example 2

[0047] The preparation method and steps of Example 1 were followed, except that no organic montmorillonite was added. Specifically, the raw material composition of Comparative Example 2 was as follows: 5000 g (100 parts) of base bitumen; 300 g (6 parts) of star-shaped SBS; 750 g (15 parts) of waste tire rubber powder; 200 g (4 parts) of C5 / C9 petroleum resin; 300 g (6 parts) of naphthenic oil; and 15 g (0.3 parts) of sulfur. In the preparation process, only SBS and naphthenic oil were added in step (1), and the other parameters were the same as in Example 1. The performance of the obtained product is shown in Table 1.

[0048] Comparative Example 3

[0049] The preparation method and steps of Example 1 are the same, except that sulfur is not added. The raw material ratio is as follows: Specifically, the raw material ratio of Comparative Example 3 is as follows: 5000g (100 parts) of base asphalt; 300g (6 parts) of star-shaped SBS; 750g (15 parts) of waste tire rubber powder; 200g (4 parts) of C5 / C9 petroleum resin; 300g (6 parts) of naphthenic oil; 100g (2 parts) of organo-modified montmorillonite. In the preparation process, step (3) is not performed. The remaining parameters are the same as in Example 1. The performance of the obtained product is shown in Table 1.

[0050] The performance of the products obtained in the above embodiments and comparative examples was tested, and the results are shown in Table 1 below.

[0051] Table 1. Performance test results of products obtained from Examples 1-4 and Comparative Examples 1-3

[0052]

[0053] The test results in Table 1 show that Comparative Example 1 (no sulfur, no OMMT) had the worst performance in all aspects, especially its storage stability (segregation difference of 8.2℃), which was completely unacceptable. Comparative Example 2 (with sulfur, no OMMT) showed a significant improvement in performance compared to Comparative Example 1, demonstrating the effectiveness of sulfur crosslinking; however, its viscosity (62300 Pa·s) and stability (segregation difference of 2.5℃) still have room for improvement. Comparative Example 3 (no sulfur, with OMMT) also showed improved performance compared to Comparative Example 1, demonstrating the role of OMMT nano-reinforcement and physical barrier; however, its performance, especially viscosity and stability, was far inferior to Example 1, which contained both OMMT and sulfur. This indicates that the synergistic effect of nano-physical barrier and chemical crosslinking is crucial. Example 1 (basic nanocomposite system) achieved a qualitative leap in viscosity, softening point, elastic recovery, and especially storage stability compared to Comparative Examples 2 and 3. Examples 2 and 3 (introducing a single compatibilizer) further optimized the low-temperature performance and interface based on Example 1, with PP-g-MAH showing a particularly significant improvement in low-temperature ductility (35.2 cm → 41.5 cm). For Example 4 (the full-component system), all performance indicators reached their optimal levels, with a viscosity exceeding 100,000 Pa·s at 60°C, a segregation difference of only 1.1°C, and excellent performance after aging, fully demonstrating the superior technical effects brought about by multiple synergistic effects.

[0054] Compared with existing technologies (such as those represented by CN105585854B), the fundamental difference of this invention lies in the fact that it does not reduce construction viscosity by adsorbing moisture through mesoporous molecular sieves, but rather by physically blocking moisture through the nanosheets of organic montmorillonite and synergistically enhancing the intrinsic compatibility and bulk strength of the SBS / rubber powder composite system through a sulfur chemical cross-linking network. This achieves both ultra-high viscosity and ultra-high stability. The technical approach of this invention starts from enhancing the bulk, rather than temporarily reducing viscosity.

[0055] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A nanocomposite high-viscosity, high-stability modified asphalt, characterized in that, The raw materials include the following parts by weight: 100 parts base bitumen; 3-10 parts star-shaped styrene-butadiene-styrene block copolymer; 5-25 parts waste tire rubber powder of 40-80 mesh; 2-6 parts C5 / C9 copolymer petroleum resin with a softening point of 90-120℃; 2-8 parts naphthenic oil; 0.1-0.5 parts sulfur; and 1-3 parts organo-modified montmorillonite.

2. The nanocomposite high-viscosity, high-stability modified asphalt according to claim 1, characterized in that: It also contains 0.5-2 parts of maleic anhydride-grafted polypropylene.

3. The nanocomposite high-viscosity, high-stability modified asphalt according to claim 2, characterized in that: It also contains 0.1-0.5 parts of silane coupling agent.

4. The nanocomposite high-viscosity, high-stability modified asphalt according to claim 3, characterized in that, The silane coupling agent is bis-(3-triethoxysilylpropyl)tetrasulfide.

5. The nanocomposite high-viscosity, high-stability modified asphalt according to claim 1, characterized in that, The styrene / butadiene block ratio of the star-shaped styrene-butadiene-styrene block copolymer is 30 / 70.

6. The nanocomposite high-viscosity, high-stability modified asphalt according to claim 1, characterized in that, The waste tire rubber powder is desulfurized rubber powder that has undergone activation treatment.

7. The nanocomposite high-viscosity, high-stability modified asphalt according to claim 1, characterized in that, The aromatic content of the naphthenic oil is less than 10%.

8. The nanocomposite high-viscosity, high-stability modified asphalt according to claim 1, characterized in that, The sulfur in question is insoluble sulfur.

9. A nanocomposite high-viscosity, high-stability modified asphalt according to any one of claims 1 to 8, characterized in that, Its dynamic viscosity at 60℃ is not less than 80,000 Pa·s, and the difference in segregation softening point after 48 hours does not exceed 2.0℃.

10. A method for preparing nanocomposite high-viscosity, high-stability modified asphalt as described in any one of claims 1 to 9, characterized in that, Includes the following steps: (1) Swelling and nano-dispersion stage: Heat the base asphalt to 165-175℃, and add star-shaped styrene-butadiene-styrene block copolymer, naphthenic oil and organo-modified montmorillonite in sequence at a speed of 2000-3000 rpm. Maintain this temperature and shear conditions for 45-60 minutes. (2) Development and interface reaction stage: Heat the mixture obtained in step (1) to 175-185℃, add waste tire rubber powder, C5 / C9 copolymer petroleum resin, and optional maleic anhydride grafted polypropylene and / or silane coupling agent, increase the rotation speed to 4500-5500 rpm, and perform high-speed shear development for 75-105 minutes. (3) Crosslinking stabilization stage: Cool the mixture obtained in step (2) to 168-172℃, add sulfur, reduce the rotation speed to 300-500 rpm, stir at low speed for 25-35 minutes to obtain the nanocomposite high viscosity and high stability modified asphalt.

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