Composite toughening high-modulus asphalt modifier as well as preparation method and application thereof

Abstract

The invention discloses a composite toughened high-modulus asphalt modifier as well as a preparation method and application thereof. The composite toughened high-modulus asphalt modifier is prepared from the following components in parts by mass: 35 to 45 parts of PCT-G resin, 15 to 25 parts of hydrogenated styrene-butadiene block copolymer, 0.5 to 1.5 parts of graphene oxide and 4 to 8 parts of polyolefin grafted glycidyl methacrylate. The invention relates to the technical field of composite materials. According to the composite toughening high-modulus asphalt modifier and the preparation method and application thereof, the high bearing modulus of asphalt is guaranteed through PCT-G and GO, the low-temperature crack resistance is improved through SEBS and the core-shell elastomer, the problems that traditional modified asphalt is high in modulus and prone to embrittlement, high in toughness and prone to deformation are solved, and the composite toughening high-modulus asphalt modifier is suitable for heavy traffic load scenes.

Description

Technical Field

[0001] This invention relates to the field of composite materials technology, specifically to a composite toughening high modulus asphalt modifier, its preparation method, and its application. Background Technology

[0002] As traffic loads become heavier and more frequent, and extreme weather conditions such as freezing and thawing and high-temperature exposure intensify their impact on road surfaces, the performance requirements for asphalt pavements are constantly being upgraded. They need to have high modulus to resist permanent deformations such as rutting under heavy loads, good low-temperature crack resistance and toughness to avoid cracking, and at the same time, ensure performance stability during long-term use.

[0003] However, existing modification technologies are insufficient to meet these comprehensive requirements: traditional single modifiers have obvious shortcomings; elastomers (such as SBS) can improve toughness and crack resistance, but have limited effect on modulus improvement, and are prone to rutting in heavy-load road sections; resins can improve modulus and high-temperature stability, but increase asphalt brittleness and have poor compatibility with asphalt, making them prone to segregation; nanofillers (such as unmodified graphene) have reinforcing potential, but their high surface energy makes them prone to agglomeration, making it difficult for them to play a role and increasing the viscosity of the system.

[0004] To compensate for the shortcomings of single modifiers, the industry has gradually developed composite modification technology. However, new problems have emerged: the interfacial bonding between different types of modifiers (such as resin and elastomer, inorganic filler and organic polymer) is weak, the compatibility is poor, and the separation and segregation are easy, resulting in unstable performance; some solutions require special equipment or extreme process conditions, which are incompatible with conventional asphalt construction processes, thus increasing construction costs; most solutions rely on new raw materials and do not effectively utilize waste resources (such as waste polyethylene), which not only wastes resources but also increases costs. A few solutions that attempt to use recycled materials also suffer from poor modification effects due to compatibility issues.

[0005] In summary, current asphalt modification technology faces three core contradictions: "difficulty in balancing high modulus and high toughness", "mismatch between component dispersibility and performance stability", and "inability to coordinate technical performance with environmental and economic efficiency". Existing technologies cannot overcome these contradictions at the same time, and a composite modification solution that can take into account multiple properties, adapt to conventional processes, and be green and economical is needed. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the present invention is implemented through the following technical solution:

[0007] A composite toughening high-modulus asphalt modifier comprises the following components:

[0008] 35-45 parts by weight of PCT-G resin, 15-25 parts by weight of hydrogenated styrene-butadiene block copolymer (SEBS), 0.5-1.5 parts by weight of graphene oxide (GO), 4-8 parts by weight of polyolefin grafted glycidyl methacrylate (PO-g-GMA), 5-10 parts by weight of core-shell structured acrylate elastomer, 1-3 parts by weight of recycled polyethylene (RPE) modified granules, 1-3 parts by weight of zinc stearate, 0.002-0.004 parts by weight of dicumyl peroxide, 0.05-0.15 parts by weight of silane coupling agent KH550, and 0.03-0.1 parts by weight of maleic anhydride.

[0009] Preferably, it includes the following components:

[0010] 40 parts by weight of PCT-G resin, 20 parts by weight of hydrogenated styrene-butadiene block copolymer (SEBS), 1 part by weight of graphene oxide (GO), 6 parts by weight of polyolefin grafted glycidyl methacrylate (PO-g-GMA), 7.5 parts by weight of core-shell structured acrylate elastomer, 2 parts by weight of recycled polyethylene (RPE) modified granules, 2 parts by weight of zinc stearate, 0.003 parts by weight of dicumyl peroxide, 0.1 parts by weight of silane coupling agent KH550, and 0.05 parts by weight of maleic anhydride.

[0011] A method for preparing a composite toughening high-modulus asphalt modifier, characterized by comprising the following steps:

[0012] Step 1: Modification of graphene oxide (GO);

[0013] Take 0.5-1.5 parts of graphene oxide and add it to a mixture of ethanol or deionized water at a volume ratio of 3:1. Disperse the mixture by ultrasonication at 300W for 30 minutes. Then add 5-8% by weight of graphene oxide silane coupling agent KH550, heat to 60℃, and stir at 200-300rpm for 2 hours. After filtration and drying, stir with 2-3 parts of core-shell structured acrylate elastomer at 1500-2000rpm for 10 minutes to obtain GO-elastomer composite particles.

[0014] Step 2: Modification of recycled polyethylene (RPE);

[0015] Take 8-15 parts of RPE granules, ultrasonically clean and dry them at 50℃, and then heat them with maleic anhydride and dicumyl peroxide in a twin-screw extruder to 160-180℃ and melt-graft them at 180 rpm for 5 minutes to obtain RPE-g-MAH; then graft 0.5-1 parts of polyolefin with glycidyl methacrylate and knead them at 170℃ and 60 rpm for 3 minutes to obtain cross-linked modified RPE granules.

[0016] Step 3: Gradient melt blending;

[0017] The process is carried out in stages using a twin-screw extruder:

[0018] First, add 35-45 parts of PCT-G resin and 3.5-7 parts of polyolefin-grafted glycidyl methacrylate and mix at 180-200℃ and 150-170 rpm for 4-6 minutes.

[0019] In the second step, take 15-25 parts of hydrogenated styrene-butadiene block copolymer and 3-7 parts of core-shell structured acrylate elastomer and mix them at 170-190℃ and 200-220rpm for 6-8 minutes.

[0020] The third step involves adding the GO-elastomer composite particles from steps 1 and 2 to the cross-linked modified RPE particles and mixing them.

[0021] In the fourth stage, add 1-3 parts by weight of zinc stearate, control the temperature to 150-170℃, and granulate by extrusion after mixing to obtain granules A.

[0022] Step 4: Post-processing;

[0023] Particle A was vacuum dried at 60°C for 4 hours to obtain the composite toughened high modulus asphalt modifier.

[0024] Preferably, in step 1, before the graphene oxide is ultrasonically dispersed at 300W power for 30 minutes, the pH value of the dispersion is adjusted to 5-6 with 0.1mol / L hydrochloric acid.

[0025] Preferably, in step 2, after ultrasonic cleaning and drying, the RPE particles are treated for 30-50 seconds in an atmosphere of 100W argon gas and 50Pa pressure.

[0026] Preferably, in the gradient melt blending of step 3, the feeding rate of the twin-screw extruder is 15-20 kg / h, and the die head pressure is controlled at 8-12 MPa.

[0027] Preferably, before the third stage of step 3, the GO-elastomer composite particles to be added are sieved with a sieve aperture of 20-30μm to remove undispersed agglomerates, and then dried in a vacuum drying oven at 60℃ for 2 hours.

[0028] Preferably, before the third stage of step 3, the cross-linked modified RPE particles to be added are crushed to a particle size of 5-8 mm, sieved with a sieve mesh size of 8 mm to remove large cross-linked bodies, and then dried in an 80°C forced-air drying oven for 3 hours.

[0029] Preferably, in step 3, after adding zinc stearate in the fourth stage, the mixture is stirred at 150-200 rpm for 5-10 minutes while controlling the temperature.

[0030] An application of a composite toughening high modulus asphalt modifier: the composite toughening high modulus asphalt modifier is added at an amount of 3%-8% of the asphalt mass and mixed with the base asphalt for use in asphalt pavement construction.

[0031] During mixing, the base asphalt is first heated to 160-180℃, and then the modifier is added. The mixture is stirred at 180-200℃ and 500-800rpm for 30-60 minutes to form modified asphalt. This modified asphalt can be used for the surface and intermediate layers of high-grade highways, and is especially suitable for road sections that are prone to cracking in cold climates or have heavy traffic loads.

[0032] This invention provides a composite toughening high-modulus asphalt modifier, its preparation method, and its application. It possesses the following beneficial effects:

[0033] (I) This composite toughening high-modulus asphalt modifier, its preparation method, and its application utilize a composite system of "PCT-G resin (high-modulus matrix) + SEBS / core-shell acrylate elastomer (toughening component) + graphene oxide (reinforcing filler)," while simultaneously improving component compatibility with PO-g-GMA. This combination ensures the high load-bearing modulus of asphalt through PCT-G and GO, while SEBS and core-shell elastomer enhance low-temperature crack resistance, solving the problems of easy cracking and deformation of high-modulus and high-toughness asphalt in traditional modified asphalt, making it suitable for heavy traffic load scenarios.

[0034] (II) The composite toughening high modulus asphalt modifier and its preparation method and application, through the special treatment of key components designed during the preparation process: graphene oxide is ultrasonically dispersed + modified with silane coupling agent, and then compounded with elastomer to form stable particles;

[0035] Crosslinked modified RPE particles are crushed and sieved to remove agglomerates; gradient melt blending further promotes dispersion through segmented temperature and speed control. These processes effectively prevent component agglomeration, ensure uniform and stable modified asphalt performance, and reduce batch-to-batch variability.

[0036] (III) This composite toughening high-modulus asphalt modifier, its preparation method, and its application involve introducing recycled polyethylene (RPE) into the formulation and improving its compatibility with asphalt through melt grafting modification, thus transforming plastic waste into an effective modifying component. This approach reduces environmental pollution from waste polyethylene and lowers the raw material cost of the modifier.

[0037] (iv) The composite toughening high modulus asphalt modifier and its preparation method and application: the modified asphalt can cover the upper / middle layer of high-grade highways, and is especially suitable for special road sections that are prone to cracking in cold and have heavy traffic loads. It has a wide range of applications and is easy to construct. Detailed Implementation

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Example 1: The present invention provides a technical solution:

[0040] A composite toughening high-modulus asphalt modifier comprises the following components:

[0041] 35 parts by weight of PCT-G resin, 15 parts by weight of hydrogenated styrene-butadiene block copolymer (SEBS), 0.5 parts by weight of graphene oxide (GO), 4 parts by weight of polyolefin grafted glycidyl methacrylate (PO-g-GMA), 5 parts by weight of core-shell structured acrylate elastomer, 1 part by weight of recycled polyethylene (RPE) modified granules, 1 part by weight of zinc stearate, 0.002 parts by weight of dicumyl peroxide, 0.05 parts by weight of silane coupling agent KH550, and 0.03 parts by weight of maleic anhydride.

[0042] A method for preparing a composite toughening high-modulus asphalt modifier, characterized by comprising the following steps:

[0043] Step 1: Modification of graphene oxide (GO);

[0044] Take 0.5 parts of graphene oxide, adjust the pH of the dispersion to 5 with 0.1 mol / L hydrochloric acid, add it to a mixture of ethanol or deionized water with a volume ratio of 3:1, and ultrasonically disperse it at 300W for 30 minutes. Then add 5% by weight of graphene oxide silane coupling agent KH550, heat to 60℃, and stir at 200 rpm for 2 hours. After filtration and drying, stir it with 2 parts by weight of core-shell structured acrylate elastomer at 1500 rpm for 10 minutes to obtain GO-elastomer composite particles.

[0045] Step 2: Modification of recycled polyethylene (RPE);

[0046] Eight parts of RPE granules were ultrasonically cleaned and dried at 50℃, and then treated for 30s in an atmosphere of 100W argon gas and 50Pa pressure. Subsequently, they were heated to 160℃ and melt-grafted with maleic anhydride and dicumyl peroxide in a twin-screw extruder at 180rpm for 5 minutes to obtain RPE-g-MAH. Then, 0.5 parts by mass of polyolefin grafted with glycidyl methacrylate were kneaded at 170℃ and 60rpm for 3 minutes to obtain cross-linked modified RPE granules.

[0047] Step 3: Gradient melt blending;

[0048] The process is carried out in stages using a twin-screw extruder. The feed rate of the twin-screw extruder is 15 kg / h, and the die pressure is controlled at 8 MPa.

[0049] First, add 35 parts of PCT-G resin and 3.5 parts of polyolefin-grafted glycidyl methacrylate and mix at 180°C and 150 rpm for 4 minutes.

[0050] In the second step, 15 parts of hydrogenated styrene-butadiene block copolymer and 3 parts of core-shell structured acrylate elastomer were mixed at 170°C and 200 rpm for 6 minutes.

[0051] In the third step, the GO-elastomer composite particles from steps 1 and 2 are added and mixed with the cross-linked modified RPE particles. Before adding, the GO-elastomer composite particles are sieved with a sieve aperture of 20 μm to remove undispersed agglomerates, and then dried in a vacuum drying oven at 60℃ for 2 hours. The cross-linked modified RPE particles are crushed to a particle size of 5 mm, sieved with a sieve aperture of 8 mm to remove large cross-linked particles, and then dried in a forced-air drying oven at 80℃ for 3 hours.

[0052] In the fourth step, add 1 part by mass of zinc stearate, control the temperature to 150°C, mix at 150 rpm for 5 minutes, and then granulate by extrusion after mixing to obtain granules A.

[0053] Step 4: Post-processing;

[0054] Particle A was vacuum dried at 60°C for 4 hours to obtain the composite toughened high modulus asphalt modifier.

[0055] An application of a composite toughening high modulus asphalt modifier: the composite toughening high modulus asphalt modifier is added at a rate of 3% by weight of asphalt and mixed with base asphalt for use in asphalt pavement construction.

[0056] During mixing, the base asphalt is first heated to 160°C, then the modifier is added, and the mixture is stirred at 180°C and 500 rpm for 30 minutes to form modified asphalt. This modified asphalt can be used for the surface and intermediate layers of high-grade highways, and is especially suitable for road sections that are prone to cracking in cold climates or have heavy traffic loads.

[0057] Example 2: The present invention provides a technical solution:

[0058] A composite toughening high-modulus asphalt modifier comprises the following components:

[0059] 40 parts by weight of PCT-G resin, 20 parts by weight of hydrogenated styrene-butadiene block copolymer (SEBS), 1 part by weight of graphene oxide (GO), 6 parts by weight of polyolefin grafted glycidyl methacrylate (PO-g-GMA), 7.5 parts by weight of core-shell structured acrylate elastomer, 2 parts by weight of recycled polyethylene (RPE) modified granules, 2 parts by weight of zinc stearate, 0.003 parts by weight of dicumyl peroxide, 0.1 parts by weight of silane coupling agent KH550, and 0.05 parts by weight of maleic anhydride.

[0060] A method for preparing a composite toughening high-modulus asphalt modifier, characterized by comprising the following steps:

[0061] Step 1: Modification of graphene oxide (GO);

[0062] Take 1 part of graphene oxide, adjust the pH of the dispersion to 5.5 with 0.1 mol / L hydrochloric acid, add it to a mixture of ethanol or deionized water with a volume ratio of 3:1, and ultrasonically disperse it at 300W for 30 minutes. Then add 6% by weight of graphene oxide silane coupling agent KH550, heat to 60℃, and stir at 250 rpm for 2 hours. After filtration and drying, stir it with 2.5 parts of core-shell structured acrylate elastomer at 1700 rpm for 10 minutes to obtain GO-elastomer composite particles.

[0063] Step 2: Modification of recycled polyethylene (RPE);

[0064] Twelve parts of RPE granules were ultrasonically cleaned and dried at 50°C. They were then treated for 40 seconds in an atmosphere of 100W argon gas and 50Pa pressure. Subsequently, they were heated to 170°C and melt-grafted with maleic anhydride and dicumyl peroxide in a twin-screw extruder at 180rpm for 5 minutes to obtain RPE-g-MAH. Then, they were grafted with 0.75 parts of polyolefin and glycidyl methacrylate and kneaded at 170°C and 60rpm for 3 minutes to obtain cross-linked modified RPE granules.

[0065] Step 3: Gradient melt blending;

[0066] The process is carried out in stages using a twin-screw extruder. The feed rate of the twin-screw extruder is 17 kg / h, and the die pressure is controlled at 10 MPa.

[0067] First, add 40 parts of PCT-G resin and 5 parts of polyolefin-grafted glycidyl methacrylate and mix at 160 rpm for 5 minutes at 190°C.

[0068] In the second step, 20 parts of hydrogenated styrene-butadiene block copolymer and 5 parts of core-shell structured acrylate elastomer were mixed at 180°C and 210 rpm for 7 minutes.

[0069] In the third step, the GO-elastomer composite particles from steps 1 and 2 are added and mixed with the cross-linked modified RPE particles. Before adding, the GO-elastomer composite particles are sieved with a sieve aperture of 25 μm to remove undispersed agglomerates, and then dried in a vacuum drying oven at 60℃ for 2 hours. The cross-linked modified RPE particles are crushed to a particle size of 6 mm, sieved with a sieve aperture of 8 mm to remove large cross-linked particles, and then dried in a forced-air drying oven at 80℃ for 3 hours.

[0070] In the fourth step, add 2 parts by mass of zinc stearate, control the temperature to 160°C, mix at 175 pm for 6 minutes, and then granulate by extrusion after mixing to obtain granules A.

[0071] Step 4: Post-processing;

[0072] Particle A was vacuum dried at 60°C for 4 hours to obtain the composite toughened high modulus asphalt modifier.

[0073] An application of a composite toughening high modulus asphalt modifier: the composite toughening high modulus asphalt modifier is added at a rate of 6% by weight of asphalt and mixed with base asphalt for use in asphalt pavement construction.

[0074] During mixing, the base asphalt is first heated to 170°C, then the modifier is added, and the mixture is stirred at 200°C and 800 rpm for 40 minutes to form modified asphalt. This modified asphalt can be used for the surface and intermediate layers of high-grade highways, and is especially suitable for road sections that are prone to cracking in cold climates or have heavy traffic loads.

[0075] Example 3: The present invention provides a technical solution:

[0076] A composite toughening high-modulus asphalt modifier comprises the following components:

[0077] 45 parts by weight of PCT-G resin, 25 parts by weight of hydrogenated styrene-butadiene block copolymer (SEBS), 1.5 parts by weight of graphene oxide (GO), 8 parts by weight of polyolefin grafted glycidyl methacrylate (PO-g-GMA), 10 parts by weight of core-shell structured acrylate elastomer, 3 parts by weight of recycled polyethylene (RPE) modified granules, 3 parts by weight of zinc stearate, 0.004 parts by weight of dicumyl peroxide, 0.15 parts by weight of silane coupling agent KH550, and 0.1 parts by weight of maleic anhydride.

[0078] A method for preparing a composite toughening high-modulus asphalt modifier, characterized by comprising the following steps:

[0079] Step 1: Modification of graphene oxide (GO);

[0080] Take 1.5 parts of graphene oxide, adjust the pH of the dispersion to 6 with 0.1 mol / L hydrochloric acid, add it to a mixture of ethanol or deionized water with a volume ratio of 3:1, and ultrasonically disperse it at 300W for 30 minutes. Then add 8% by weight of graphene oxide silane coupling agent KH550, heat to 60℃, and stir at 300 rpm for 2 hours. After filtration and drying, stir it with 3 parts of core-shell structure acrylate elastomer at 2000 rpm for 10 minutes to obtain GO-elastomer composite particles.

[0081] Step 2: Modification of recycled polyethylene (RPE);

[0082] Fifteen parts of RPE granules were ultrasonically cleaned and dried at 50℃, then treated for 50s in an atmosphere of 100W argon gas and 50Pa pressure. Subsequently, they were heated to 180℃ and melt-grafted with maleic anhydride and dicumyl peroxide in a twin-screw extruder at 180rpm for 5 minutes to obtain RPE-g-MAH. Then, they were grafted with 1 part of polyolefin and glycidyl methacrylate and kneaded at 170℃ at 60rpm for 3 minutes to obtain cross-linked modified RPE granules.

[0083] Step 3: Gradient melt blending;

[0084] The process is carried out in stages using a twin-screw extruder. The feed rate of the twin-screw extruder is 20 kg / h, and the die pressure is controlled at 12 MPa.

[0085] First, add 45 parts of PCT-G resin and 7 parts of polyolefin-grafted glycidyl methacrylate and mix at 200°C and 170 rpm for 6 minutes.

[0086] In the second step, 25 parts of hydrogenated styrene-butadiene block copolymer and 7 parts of core-shell structured acrylate elastomer were mixed at 190°C and 220 rpm for 8 minutes.

[0087] In the third step, the GO-elastomer composite particles from steps 1 and 2 are added and mixed with the cross-linked modified RPE particles. Before adding, the GO-elastomer composite particles are sieved with a sieve aperture of 30 μm to remove undispersed agglomerates, and then dried in a vacuum drying oven at 60℃ for 2 hours. The cross-linked modified RPE particles are crushed to a particle size of 8 mm, sieved with a sieve aperture of 8 mm to remove large cross-linked particles, and then dried in a forced-air drying oven at 80℃ for 3 hours.

[0088] In the fourth stage, add 3 parts by mass of zinc stearate, control the temperature to 170°C, mix at 200 rpm for 10 minutes, and then granulate by extrusion after mixing to obtain granules A.

[0089] Step 4: Post-processing;

[0090] Particle A was vacuum dried at 60°C for 4 hours to obtain the composite toughened high modulus asphalt modifier.

[0091] An application of a composite toughening high modulus asphalt modifier: the composite toughening high modulus asphalt modifier is added at an amount of 8% of the asphalt mass and mixed with the base asphalt for use in asphalt pavement construction.

[0092] During mixing, the base asphalt is first heated to 180°C, then the modifier is added, and the mixture is stirred at 200°C and 800 rpm for 60 minutes to form modified asphalt. This modified asphalt can be used for the surface and intermediate layers of high-grade highways, and is especially suitable for road sections that are prone to cracking in cold climates or have heavy traffic loads.

[0093] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0094] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A composite toughening high-modulus asphalt modifier, characterized in that, Includes the following components: 35-45 parts by weight of PCT-G resin, 15-25 parts by weight of hydrogenated styrene-butadiene block copolymer, 0.5-1.5 parts by weight of graphene oxide, 4-8 parts by weight of polyolefin grafted glycidyl methacrylate, 5-10 parts by weight of core-shell structured acrylate elastomer, 1-3 parts by weight of recycled polyethylene modified granules, 1-3 parts by weight of zinc stearate, 0.002-0.004 parts by weight of dicumyl peroxide, 0.05-0.15 parts by weight of silane coupling agent KH550, and 0.03-0.1 parts by weight of maleic anhydride.

2. The composite toughening high-modulus asphalt modifier according to claim 1, characterized in that, Includes the following components: 40 parts by weight of PCT-G resin, 20 parts by weight of hydrogenated styrene-butadiene block copolymer, 1 part by weight of graphene oxide, 6 parts by weight of polyolefin grafted glycidyl methacrylate, 7.5 parts by weight of core-shell structured acrylate elastomer, 2 parts by weight of recycled polyethylene modified granules, 2 parts by weight of zinc stearate, 0.003 parts by weight of dicumyl peroxide, 0.1 parts by weight of silane coupling agent KH550, and 0.05 parts by weight of maleic anhydride.

3. A method for preparing a composite toughening high-modulus asphalt modifier, characterized in that, Includes the following steps: Step 1: Modification of graphene oxide; Take 0.5-1.5 parts of graphene oxide and add it to a mixture of ethanol or deionized water at a volume ratio of 3:

1. Disperse the mixture by ultrasonication at 300W for 30 minutes. Then add 5-8% by weight of graphene oxide silane coupling agent KH550, heat to 60℃, and stir at 200-300rpm for 2 hours. After filtration and drying, stir with 2-3 parts of core-shell structured acrylate elastomer at 1500-2000rpm for 10 minutes to obtain GO-elastomer composite particles. Step 2: Modification of recycled polyethylene; Take 8-15 parts of RPE granules, ultrasonically clean and dry them at 50℃, and then heat them with maleic anhydride and dicumyl peroxide in a twin-screw extruder to 160-180℃ and melt-graft them at 180 rpm for 5 minutes to obtain RPE-g-MAH; then graft 0.5-1 parts of polyolefin with glycidyl methacrylate and knead them at 170℃ and 60 rpm for 3 minutes to obtain cross-linked modified RPE granules. Step 3: Gradient melt blending; The process is carried out in stages using a twin-screw extruder: First, add 35-45 parts of PCT-G resin and 3.5-7 parts of polyolefin-grafted glycidyl methacrylate and mix at 180-200℃ and 150-170 rpm for 4-6 minutes. In the second step, take 15-25 parts of hydrogenated styrene-butadiene block copolymer and 3-7 parts of core-shell structured acrylate elastomer and mix them at 170-190℃ and 200-220rpm for 6-8 minutes. The third step involves adding the GO-elastomer composite particles from steps 1 and 2 to the cross-linked modified RPE particles and mixing them. In the fourth stage, add 1-3 parts by weight of zinc stearate, control the temperature to 150-170℃, and granulate by extrusion after mixing to obtain granules A. Step 4: Post-processing; Particle A was vacuum dried at 60°C for 4 hours to obtain the composite toughened high modulus asphalt modifier.

4. The method for preparing a composite toughening high-modulus asphalt modifier according to claim 3, characterized in that: In step 1, before the graphene oxide is ultrasonically dispersed at 300W power for 30 minutes, the pH value of the dispersion is adjusted to 5-6 with 0.1mol / L hydrochloric acid.

5. The method for preparing a composite toughening high-modulus asphalt modifier according to claim 3, characterized in that: In step 2, after ultrasonic cleaning and drying, the RPE particles are treated for 30-50 seconds in an atmosphere of 100W argon gas and 50Pa pressure.

6. The method for preparing a composite toughening high-modulus asphalt modifier according to claim 3, characterized in that: In the gradient melt blending process in step 3, the feeding rate of the twin-screw extruder is 15-20 kg / h, and the die head pressure is controlled at 8-12 MPa.

7. The method for preparing a composite toughening high-modulus asphalt modifier according to claim 6, characterized in that: Before the third stage of step 3, the GO-elastomer composite particles to be added are sieved with a mesh size of 20-30μm, and then dried in a vacuum drying oven at 60℃ for 2 hours.

8. The method for preparing a composite toughening high-modulus asphalt modifier according to claim 6, characterized in that: Before the third stage of step 3, the cross-linked modified RPE particles to be added are crushed to a particle size of 5-8 mm, sieved, and then dried in an 80°C forced-air drying oven for 3 hours.

9. The method for preparing a composite toughening high-modulus asphalt modifier according to claim 6, characterized in that: In step 3, after adding zinc stearate in the fourth stage, mix at 150-200 rpm for 5-10 minutes while controlling the temperature.

10. The application of a composite toughening high-modulus asphalt modifier, characterized in that: The composite toughening high modulus asphalt modifier is added at a rate of 3%-8% of the asphalt mass and mixed with the base asphalt for use in asphalt pavement construction. During mixing, the base asphalt is first heated to 160-180℃, then the modifier is added, and the mixture is stirred at 180-200℃ and 500-800 rpm for 30-60 minutes to form modified asphalt. This modified asphalt can be used in the top and middle layers of high-grade highways, and is especially suitable for road sections that are prone to cracking in cold climates or under heavy traffic loads.