High-RAP-mixing-amount cold-mixed asphalt regenerant and preparation method thereof

Abstract

The invention discloses a high-RAP-doping-amount cold-mixed asphalt regenerant, and particularly relates to the technical field of asphalt regenerant, the high-RAP-doping-amount cold-mixed asphalt regenerant comprises the following raw materials: hydrogenated extract oil, acetyl tributyl citrate, a low-temperature penetrant, pre-swelling SEBS master batch, a crosslinking catalyst and a microcapsule antioxidant. Molecular-level branched-chain alkyl sodium sulfonate can be wedged into aged asphalt microcracks at the temperature of 65 DEG C, lost light components are balanced and supplemented through hydrogenated extract oil, an SEBS micro-crosslinking network forms an in-situ reinforcement effect at the temperature of 90 DEG C, the triple regeneration effect of regenerated asphalt is achieved, and the service life of the regenerated asphalt is prolonged. Nano-zinc oxide is treated by a silane coupling agent and then is modified by using methyl methacrylate and potassium persulfate, so that the nano-zinc oxide is coated with polymethyl methacrylate, the compatibility of the microcapsule antioxidant and the recycled asphalt can be improved, and the anti-aging performance of the recycled asphalt is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of asphalt regeneration agents, and more particularly to a high RAP content cold mix asphalt regeneration agent and a preparation method thereof. Background Art

[0002] Recycled asphalt pavement materials are subjected to the elements, including sunlight, precipitation, high temperatures, and repeated vehicle loads, which can cause asphalt aging. Recycling recycled asphalt aggregate (RAP) effectively disposes of waste, reduces the extraction of new materials, and conserves significant amounts of asphalt and gravel, thereby saving construction costs, conserving resources, and protecting the ecological environment.

[0003] However, due to limitations in material development and construction technology, the current utilization rate of recycled asphalt pavement materials in China remains low, averaging around 30%. As the use of recycled materials increases, the low-temperature performance of recycled asphalt mixtures gradually deteriorates, failing to meet usage requirements. This is closely related to the performance of recycled asphalt mixtures. Excessive inclusion of RAP often negatively impacts the performance of recycled asphalt mixtures. The quality of regeneration agents is a crucial factor in determining the performance of recycled asphalt mixtures. Therefore, the development of new asphalt regeneration agents to efficiently recycle RAP is an inevitable trend in the future of road engineering.

[0004] Most existing asphalt regeneration agents use high-temperature or medium-temperature mixing. During high-temperature mixing, the temperature is controlled at above 160°C, while during medium-temperature mixing, the temperature is controlled at above 130°C. However, high-temperature mixing and medium-temperature mixing require more energy consumption due to the higher temperatures, and are prone to produce more VOC substances, which are harmful to human health.

[0005] However, although there are many types of existing asphalt regeneration agents, most of them are composed of low-viscosity light oil, or anti-aging agents and other blending components are added to them. Such regeneration agents have poor regeneration effects, and the stability, low-temperature crack resistance and fatigue durability of the regenerated asphalt mixtures can no longer meet people's usage needs. Summary of the Invention

[0006] To overcome the aforementioned shortcomings of the prior art, embodiments of the present invention provide a high-RAP cold-mix asphalt rejuvenator and its preparation method. These methods aim to address the existing issues of insufficient stability and poor low-temperature crack resistance associated with cold-mix asphalt rejuvenators at high RAP (recycled asphalt mixture) dosages. By optimizing the formulation and process, the present invention significantly improves the regenerated asphalt's low-temperature mixing adaptability, long-term stability, and crack resistance while maintaining a high RAP dosage (≥50%), providing a highly effective solution for green road construction in cold regions or low-temperature environments.

[0007] To achieve the above-mentioned object, the present invention provides the following technical solution: a high-RAP content cold-mix asphalt regeneration agent, wherein the high-RAP content cold-mix asphalt regeneration agent comprises the following raw materials in parts by weight: 50-65 parts of hydrogenated extracted oil, 18-26 parts of acetyl tributyl citrate, 5-10 parts of low-temperature penetrant, 5-15 parts of pre-swollen SEBS masterbatch, 0.5-1.0 parts of cross-linking catalyst, and 2-2.5 parts of microcapsule antioxidant.

[0008] In a preferred embodiment, the high RAP content cold mix asphalt regeneration agent includes the following raw materials in parts by weight: 55-60 parts of hydrogenated extracted oil, 20-24 parts of acetyl tributyl citrate, 7-9 parts of low-temperature penetrant, 8-12 parts of pre-swollen SEBS masterbatch, 0.7-0.9 parts of cross-linking catalyst, and 2.1-2.3 parts of microcapsule antioxidant.

[0009] In a preferred embodiment, the high RAP content cold mix asphalt regeneration agent includes the following raw materials in parts by weight: 58 parts of hydrogenated extracted oil, 22 parts of acetyl tributyl citrate, 8 parts of low-temperature penetrant, 10 parts of pre-swollen SEBS masterbatch, 0.8 parts of cross-linking catalyst, and 2.2 parts of microcapsule antioxidant.

[0010] In a preferred embodiment, the hydrogenation-extracted oil is furfural-extracted oil, and the cross-linking catalyst is dibutyltin dilaurate.

[0011] In a preferred embodiment, the preparation method of the microcapsule antioxidant is: S1: Dispersing nano zinc oxide in a mixture of ethanol and water, ultrasonically treating for 1-2 hours, then adding a silane coupling agent, stirring and reacting at 30-50° C. for 4-8 hours to obtain pretreated nano zinc oxide; S2: Dispersing the pretreated nano-zinc oxide in methyl methacrylate monomer, adding potassium persulfate initiator, and conducting polymerization reaction under nitrogen protection. After the polymerization reaction is completed, the product is centrifuged and separated, washed with ethanol, and then vacuum-dried at 60-80°C to obtain modified nano-zinc oxide; S3: Antioxidant 1010 was mixed with modified nano zinc oxide and coated with ethyl cellulose to prepare a microcapsule antioxidant.

[0012] In a preferred embodiment, the volume ratio of ethanol to water in step S1 is 1:(8-10), the amount of the silane coupling agent added is (0.5-2%) of the mass of the nano-zinc oxide, the concentration of potassium persulfate in step S2 is 0.5-2%, the polymerization temperature is 60-80°C, the reaction time is 4-6 hours, the mass ratio of antioxidant 1010 to modified nano-zinc oxide in step S3 is (4-6):1, and the particle size of ethyl cellulose is 10-15 μm.

[0013] In a preferred embodiment, the preparation method of the pre-swollen SEBS masterbatch is: Add 5-8% of naphthenic oil to the SEBS masterbatch, stir and react at 80-90°C for 30-60 minutes, and then add 3% of maleic anhydride for grafting to obtain a pre-swollen SEBS masterbatch.

[0014] In a preferred embodiment, the preparation method of the low-temperature penetrant is: A hydrogen peroxide oxidant is added to the weighed branched alkyl sodium sulfonate to convert the terminal alkyl group of the branched alkyl sodium sulfonate into a carboxylic acid group, and then a dicyclohexylcarbodiimide coupling agent and glycidylamine are added, and the reaction is carried out under an inert gas at 0-5°C for 20-60 minutes to obtain a low-temperature penetrant.

[0015] The present invention also provides a method for preparing a cold mix asphalt regeneration agent with a high RAP content, comprising the following steps: Step 1: Weigh each raw material according to the above weight parts, heat the weighed hydrogenated extracted oil to 65-75℃, add acetyl tributyl citrate plasticizer and stir for 25-35 minutes, add low-temperature penetrant after stirring for 20 minutes; then heat to 85-95℃ and add pre-swollen SEBS masterbatch, then add cross-linking catalyst and carry out cross-linking catalysis for 30 minutes, cool the temperature to 60-70℃ and add microcapsule antioxidant, continue stirring at 60℃ for 20 minutes, and obtain high RAP content cold mix asphalt regeneration agent after cooling to room temperature.

[0016] In a preferred embodiment, the ultrasonic dispersion of the low-temperature penetrant is carried out by adopting an ultrasonic-mechanical blending composite dispersion process, and the ultrasonic power is ≥400W.

[0017] Technical effects and advantages of the present invention: 1. The high-RAP cold-mix asphalt rejuvenator of the present invention uses molecular-grade branched-chain sodium alkyl sulfonate to wedge into the microcracks of aged asphalt at 65°C, and uses hydrogenated extracted oil to balance and replenish the lost light components. The SEBS micro-crosslinked network forms an in-situ reinforcement effect at 90°C, achieving a triple regeneration effect of regenerated asphalt; 2. The microcapsule antioxidant of the present invention is composed of an antioxidant and modified nano zinc oxide. Nano zinc oxide itself has good ultraviolet light absorption ability, which reduces the hardening and embrittlement of asphalt caused by photooxidation. It can also fill the voids in asphalt, enhance cohesion, and stabilize the regenerated asphalt. Nano zinc oxide is treated with a silane coupling agent and then modified with methyl methacrylate and potassium persulfate, so that the nano zinc oxide is coated with polymethyl methacrylate, which can improve the compatibility of the microcapsule antioxidant with the regenerated asphalt, thereby improving the anti-aging performance of the regenerated asphalt. 3. The present invention uses low-melting-point (70-80°C) high-aromatic content extracted oil as the masterbatch carrier. The added naphthenic oil (such as KN4010) has a ring structure that can be inserted into the EB rubber phase of the SEBS masterbatch to promote swelling. The addition of maleic anhydride to graft SEBS improves compatibility with asphalt and can reduce the mixing temperature of the regeneration agent to 80-100°C, thereby reducing energy consumption and VOC emissions. 4. The present invention uses branched alkyl sodium sulfonate as a penetrant to improve the penetration effect of the asphalt regeneration agent. The branched alkyl sodium sulfonate first uses hydrogen peroxide to convert the terminal alkyl group into a carboxylic acid group, and then uses glycidylamine to form an amide bond and introduces an epoxy group, which can enhance the chemical bonding with the polar groups in the asphalt, improve the dispersion stability, and make the regenerated asphalt have a better penetration effect. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention. Example

[0019] The present invention provides a high-RAP content cold-mix asphalt rejuvenator, which comprises the following raw materials in parts by weight: 50 parts of hydrogenated extracted oil, 18 parts of acetyl tributyl citrate, 5 parts of low-temperature penetrant, 5 parts of pre-swollen SEBS masterbatch, 0.5 parts of cross-linking catalyst, and 2 parts of microcapsule antioxidant.

[0020] In a preferred embodiment, the hydrogenation-extracted oil is furfural-extracted oil, and the cross-linking catalyst is dibutyltin dilaurate.

[0021] In a preferred embodiment, the preparation method of the microcapsule antioxidant is: S1: Dispersing nano-zinc oxide in a mixture of ethanol and water, ultrasonically treating for 1.5 hours, then adding a silane coupling agent, stirring and reacting at 40°C for 6 hours to obtain pretreated nano-zinc oxide; S2: Dispersing the pretreated nano-zinc oxide in methyl methacrylate monomer, adding potassium persulfate initiator, and conducting polymerization under nitrogen protection. After the polymerization reaction is completed, the product is centrifuged and separated, washed with ethanol, and then dried in vacuum at 70°C to obtain modified nano-zinc oxide; S3: Antioxidant 1010 was mixed with modified nano zinc oxide and coated with ethyl cellulose to prepare a microcapsule antioxidant.

[0022] In a preferred embodiment, the volume ratio of ethanol to water in step S1 is 1:9, the amount of the silane coupling agent added is 1.5 of the mass of the nano-zinc oxide, the concentration of potassium persulfate in step S2 is 1.3%, the polymerization temperature is 70°C, the reaction time is 5 hours, the mass ratio of the antioxidant 1010 to the modified nano-zinc oxide in step S3 is 5:1, and the particle size of the ethyl cellulose is 10-15 μm.

[0023] In a preferred embodiment, the preparation method of the pre-swollen SEBS masterbatch is: 7% of naphthenic oil was added to the SEBS masterbatch, stirred and reacted at 85°C for 45 minutes, and then 3% of maleic anhydride was added for grafting to obtain the pre-swollen SEBS masterbatch.

[0024] In a preferred embodiment, the preparation method of the low-temperature penetrant is: Hydrogen peroxide oxidant was added to the weighed branched alkyl sodium sulfonate to convert the terminal alkyl group of the branched alkyl sodium sulfonate into a carboxylic acid group. Then, dicyclohexylcarbodiimide coupling agent and glycidylamine were added, and the mixture was reacted under inert gas at 3°C for 40 minutes to obtain a low-temperature penetrant.

[0025] The present invention also provides a method for preparing a cold mix asphalt regeneration agent with a high RAP content, comprising the following steps: Step 1: Weigh each raw material according to the above weight parts, heat the weighed hydrogenated extracted oil to 70℃, add acetyl tributyl citrate plasticizer and stir for 30 minutes, add low-temperature penetrant after stirring for 20 minutes; then heat to 90℃ and add pre-swollen SEBS masterbatch, then add cross-linking catalyst and carry out cross-linking catalysis for 30 minutes, cool the temperature to 65℃ and add microcapsule antioxidant, continue stirring at 60℃ for 20 minutes, and obtain high RAP content cold mix asphalt regeneration agent after cooling to room temperature.

[0026] In a preferred embodiment, the ultrasonic dispersion of the low-temperature penetrant is carried out by adopting an ultrasonic-mechanical blending composite dispersion process, and the ultrasonic power is ≥400W. Example

[0027] Different from Example 1, the high RAP content cold mix asphalt regeneration agent includes the following raw materials in parts by weight: 58 parts of hydrogenated extracted oil, 22 parts of acetyl tributyl citrate, 8 parts of low-temperature penetrant, 10 parts of pre-swollen SEBS masterbatch, 0.8 parts of cross-linking catalyst, and 2.2 parts of microcapsule antioxidant. Example

[0028] Different from Examples 1-2, the high RAP content cold mix asphalt regeneration agent includes the following raw materials in parts by weight: 65 parts of hydrogenated extracted oil, 26 parts of acetyl tributyl citrate, 10 parts of low-temperature penetrant, 15 parts of pre-swollen SEBS masterbatch, 1.0 part of cross-linking catalyst, and 2.5 parts of microcapsule antioxidant.

[0029] Comparative Example 1: The present invention provides a high-RAP content cold-mix asphalt rejuvenator, which comprises the following raw materials in parts by weight: 50 parts of hydrogenated extracted oil, 18 parts of acetyl tributyl citrate, 5 parts of low-temperature penetrant, 5 parts of pre-swollen SEBS masterbatch, 0.5 parts of cross-linking catalyst, and 2 parts of microcapsule antioxidant.

[0030] In a preferred embodiment, the hydrogenation-extracted oil is furfural-extracted oil, and the cross-linking catalyst is dibutyltin dilaurate.

[0031] In a preferred embodiment, the preparation method of the microcapsule antioxidant is: S1: Dispersing nano-zinc oxide in a mixture of ethanol and water, ultrasonically treating for 1.5 hours, then adding a silane coupling agent, stirring and reacting at 40°C for 6 hours to obtain pretreated nano-zinc oxide; S2: Dispersing the pretreated nano-zinc oxide in methyl methacrylate monomer, adding potassium persulfate initiator, and conducting polymerization under nitrogen protection. After the polymerization reaction is completed, the product is centrifuged and separated, washed with ethanol, and then dried in vacuum at 70°C to obtain modified nano-zinc oxide; S3: Antioxidant 1010 was mixed with modified nano zinc oxide and coated with ethyl cellulose to prepare a microcapsule antioxidant.

[0032] In a preferred embodiment, the volume ratio of ethanol to water in step S1 is 1:9, the amount of the silane coupling agent added is 1.5 of the mass of the nano-zinc oxide, the concentration of potassium persulfate in step S2 is 1.3%, the polymerization temperature is 70°C, the reaction time is 5 hours, the mass ratio of the antioxidant 1010 to the modified nano-zinc oxide in step S3 is 5:1, and the particle size of the ethyl cellulose is 10-15 μm.

[0033] In a preferred embodiment, the preparation method of the pre-swollen SEBS masterbatch is: 7% of naphthenic oil was added to the SEBS masterbatch, stirred and reacted at 85°C for 45 minutes, and then 3% of maleic anhydride was added for grafting to obtain the pre-swollen SEBS masterbatch.

[0034] In a preferred embodiment, the low-temperature penetrant is branched alkyl sodium sulfonate.

[0035] The present invention also provides a method for preparing a cold mix asphalt regeneration agent with a high RAP content, comprising the following steps: Step 1: Weigh each raw material according to the above weight parts, heat the weighed hydrogenated extracted oil to 70℃, add acetyl tributyl citrate plasticizer and stir for 30 minutes, add low-temperature penetrant after stirring for 20 minutes; then heat to 90℃ and add pre-swollen SEBS masterbatch, then add cross-linking catalyst and carry out cross-linking catalysis for 30 minutes, cool the temperature to 65℃ and add microcapsule antioxidant, continue stirring at 60℃ for 20 minutes, and obtain high RAP content cold mix asphalt regeneration agent after cooling to room temperature.

[0036] In a preferred embodiment, the ultrasonic dispersion of the low-temperature penetrant is carried out by adopting an ultrasonic-mechanical blending composite dispersion process, and the ultrasonic power is ≥400W.

[0037] Comparative Example 2: The present invention provides a high-RAP content cold-mix asphalt rejuvenator, which includes the following raw materials in parts by weight: 50 parts of hydrogenated extracted oil, 18 parts of acetyl tributyl citrate, 5 parts of low-temperature penetrant, 5 parts of SEBS masterbatch, 0.5 parts of cross-linking catalyst, and 2 parts of microcapsule antioxidant.

[0038] In a preferred embodiment, the hydrogenation-extracted oil is furfural-extracted oil, and the cross-linking catalyst is dibutyltin dilaurate.

[0039] In a preferred embodiment, the preparation method of the microcapsule antioxidant is: S1: Dispersing nano-zinc oxide in a mixture of ethanol and water, ultrasonically treating for 1.5 hours, then adding a silane coupling agent, stirring and reacting at 40°C for 6 hours to obtain pretreated nano-zinc oxide; S2: Dispersing the pretreated nano-zinc oxide in methyl methacrylate monomer, adding potassium persulfate initiator, and conducting polymerization under nitrogen protection. After the polymerization reaction is completed, the product is centrifuged and separated, washed with ethanol, and then dried in vacuum at 70°C to obtain modified nano-zinc oxide; S3: Antioxidant 1010 was mixed with modified nano zinc oxide and coated with ethyl cellulose to prepare a microcapsule antioxidant.

[0040] In a preferred embodiment, the volume ratio of ethanol to water in step S1 is 1:9, the amount of the silane coupling agent added is 1.5 of the mass of the nano-zinc oxide, the concentration of potassium persulfate in step S2 is 1.3%, the polymerization temperature is 70°C, the reaction time is 5 hours, the mass ratio of the antioxidant 1010 to the modified nano-zinc oxide in step S3 is 5:1, and the particle size of the ethyl cellulose is 10-15 μm.

[0041] In a preferred embodiment, the preparation method of the low-temperature penetrant is: Hydrogen peroxide oxidant was added to the weighed branched alkyl sodium sulfonate to convert the terminal alkyl group of the branched alkyl sodium sulfonate into a carboxylic acid group. Then, dicyclohexylcarbodiimide coupling agent and glycidylamine were added, and the mixture was reacted under inert gas at 3°C for 40 minutes to obtain a low-temperature penetrant.

[0042] The present invention also provides a method for preparing a cold mix asphalt regeneration agent with a high RAP content, comprising the following steps: Step 1: Weigh each raw material according to the above weight parts, heat the weighed hydrogenated extracted oil to 70℃, add acetyl tributyl citrate plasticizer and stir for 30 minutes, add low-temperature penetrant after stirring for 20 minutes; then heat to 90℃ and add pre-swollen SEBS masterbatch, then add cross-linking catalyst and carry out cross-linking catalysis for 30 minutes, cool the temperature to 65℃ and add microcapsule antioxidant, continue stirring at 60℃ for 20 minutes, and obtain high RAP content cold mix asphalt regeneration agent after cooling to room temperature.

[0043] In a preferred embodiment, the ultrasonic dispersion of the low-temperature penetrant is carried out by adopting an ultrasonic-mechanical blending composite dispersion process, and the ultrasonic power is ≥400W.

[0044] Comparative Example 3: The high RAP content cold mix asphalt regeneration agent includes the following raw materials in parts by weight: 50 parts of hydrogenated extracted oil, 18 parts of acetyl tributyl citrate, 5 parts of low-temperature penetrant, 5 parts of pre-swollen SEBS masterbatch, 0.5 parts of cross-linking catalyst, and 2 parts of microcapsule antioxidant.

[0045] In a preferred embodiment, the hydrogenation-extracted oil is furfural-extracted oil, and the cross-linking catalyst is dibutyltin dilaurate.

[0046] In a preferred embodiment, the preparation method of the microcapsule antioxidant is: S1: Antioxidant 1010 was mixed with nano zinc oxide and coated with ethyl cellulose to prepare a microcapsule antioxidant.

[0047] In a preferred embodiment, in step S3, the mass ratio of the antioxidant 1010 to the modified nano zinc oxide is 5:1, and the particle size of the ethyl cellulose is 10-15 μm.

[0048] In a preferred embodiment, the preparation method of the pre-swollen SEBS masterbatch is: 7% of naphthenic oil was added to the SEBS masterbatch, stirred and reacted at 85°C for 45 minutes, and then 3% of maleic anhydride was added for grafting to obtain the pre-swollen SEBS masterbatch.

[0049] In a preferred embodiment, the preparation method of the low-temperature penetrant is: Hydrogen peroxide oxidant was added to the weighed branched alkyl sodium sulfonate to convert the terminal alkyl group of the branched alkyl sodium sulfonate into a carboxylic acid group. Then, dicyclohexylcarbodiimide coupling agent and glycidylamine were added, and the mixture was reacted under inert gas at 3°C for 40 minutes to obtain a low-temperature penetrant.

[0050] The present invention also provides a method for preparing a cold mix asphalt regeneration agent with a high RAP content, comprising the following steps: Step 1: Weigh each raw material according to the above weight parts, heat the weighed hydrogenated extracted oil to 70℃, add acetyl tributyl citrate plasticizer and stir for 30 minutes, add low-temperature penetrant after stirring for 20 minutes; then heat to 90℃ and add pre-swollen SEBS masterbatch, then add cross-linking catalyst and carry out cross-linking catalysis for 30 minutes, cool the temperature to 65℃ and add microcapsule antioxidant, continue stirring at 60℃ for 20 minutes, and obtain high RAP content cold mix asphalt regeneration agent after cooling to room temperature.

[0051] In a preferred embodiment, the ultrasonic dispersion of the low-temperature penetrant is carried out by adopting an ultrasonic-mechanical blending composite dispersion process, and the ultrasonic power is ≥400W.

[0052] After heating the old asphalt, the regeneration agents prepared in Examples 1-3 and Comparative Examples 1-3 were added, and the mixtures were mixed at 100°C to prepare asphalt mixtures as Example 1, Example 2, Example 3 and Control Groups 1, 2, and 3. The Marshall stability, dynamic stability, VOC emission, needle penetration, softening point, and freeze-thaw splitting strength ratio were tested using the methods in the "JTGE20-2011 Test Procedure for Asphalt and Asphalt Mixtures for Highway Engineering". The measurement results are shown in Table 1:

[0053] Table 1 It can be seen from Table 1 that the asphalt regeneration agent produced by this embodiment has good stability and permeability when applied to cold mix asphalt with high RAP content, and has low VOC emissions. Compared with Example 1, Comparative Example 1 uses untreated branched alkyl sodium sulfonate as the penetrant, and its penetration effect is reduced. Compared with Example 1, Comparative Example 2 uses ordinary SEBS masterbatch, and its stability is reduced; and Compared with Example 1, Comparative Example 3 does not modify the nano zinc oxide, and its stability and penetration effect are reduced. Therefore, molecular-grade branched sodium alkyl sulfonate can be used to wedge into the microcracks of aged asphalt at 65°C, and hydrogenation-extracted oil is used to balance and supplement the lost light components. The SEBS micro-crosslinked network forms an in-situ reinforcement effect at 90°C, achieving a triple regeneration effect of regenerated asphalt. The microcapsule antioxidant is composed of an antioxidant and modified nano zinc oxide. Nano zinc oxide itself has good ultraviolet light absorption capacity, which reduces the hardening and embrittlement of asphalt caused by photooxidation, and can fill the voids in asphalt, enhance cohesion, and stabilize the regenerated asphalt. Nano zinc oxide is treated with a silane coupling agent and then modified with methyl methacrylate and potassium persulfate, so that the nano zinc oxide is coated with polymethyl methacrylate, which can improve the compatibility of the microcapsule antioxidant with the regenerated asphalt, thereby improving the regeneration efficiency. Anti-aging performance of asphalt; low melting point (70-80℃) high aromatic content extracted oil is used as the masterbatch carrier, and the added cycloparaffinic oil (such as KN4010) has a ring structure that can be inserted into the EB rubber phase of SEBS masterbatch to promote swelling. Maleic anhydride is added to graft SEBS to improve compatibility with asphalt, which can reduce the mixing temperature of the regeneration agent, reduce energy consumption, and also reduce VOC emissions; branched chain sodium alkyl sulfonate is used as a penetrant to improve the penetration effect of the asphalt regeneration agent, and branched chain sodium alkyl sulfonate uses hydrogen peroxide to first convert the terminal alkyl group into a carboxylic acid group, and then uses glycidylamine to form an amide bond, and introduces an epoxy group, which can enhance the chemical bonding with the polar groups in the asphalt, improve the dispersion stability, and make the regenerated asphalt have a better penetration effect.

[0054] Application Case: Municipal Trunk Road Application. AC-13 gradation, 4cm thick: RAP content 60%, regeneration agent addition (accounting for the old asphalt content in the RAP material) 9%, mixing at 100°C. The mixed asphalt mixture was tested for Marshall stability, dynamic stability, and VOC emissions. The measured indicators are shown in Table 2:

[0055] Table 2 As can be seen from Table 2, the asphalt regeneration agent of the present invention can be applied to the low-temperature mixing of asphalt mixture. When the RAP content reaches 60%, the strength of the fresh mix is higher and the VOC emission is lower.

[0056] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high RAP content cold mix asphalt rejuvenator, characterized by: The high RAP content cold mix asphalt regeneration agent includes the following raw materials in parts by weight: 50-65 parts of hydrogenated extracted oil, 18-26 parts of acetyl tributyl citrate, 5-10 parts of low-temperature penetrant, 5-15 parts of pre-swelling SEBS masterbatch, 0.5-1.0 parts of cross-linking catalyst, and 2-2.5 parts of microcapsule antioxidant.

2. The high RAP content cold mix asphalt rejuvenator according to claim 1, characterized in that: The high RAP content cold mix asphalt regeneration agent includes the following raw materials in parts by weight: 55-60 parts of hydrogenated extracted oil, 20-24 parts of acetyl tributyl citrate, 7-9 parts of low-temperature penetrant, 8-12 parts of pre-swelling SEBS masterbatch, 0.7-0.9 parts of cross-linking catalyst, and 2.1-2.3 parts of microcapsule antioxidant.

3. The high RAP content cold mix asphalt rejuvenator according to claim 1, characterized in that: The high RAP content cold mix asphalt regeneration agent includes the following raw materials in parts by weight: 58 parts of hydrogenated extracted oil, 22 parts of acetyl tributyl citrate, 8 parts of low-temperature penetrant, 10 parts of pre-swollen SEBS masterbatch, 0.8 parts of cross-linking catalyst, and 2.2 parts of microcapsule antioxidant.

4. The high RAP content cold mix asphalt rejuvenator according to claim 1, characterized in that: The hydrogenation extracted oil is furfural extracted oil, and the cross-linking catalyst is dibutyltin dilaurate.

5. The high RAP content cold mix asphalt rejuvenator according to claim 1, characterized in that: The preparation method of the microcapsule antioxidant is as follows: S1: Dispersing nano zinc oxide in a mixture of ethanol and water, ultrasonically treating for 1-2 hours, then adding a silane coupling agent, stirring and reacting at 30-50° C. for 4-8 hours to obtain pretreated nano zinc oxide; S2: Dispersing the pretreated nano-zinc oxide in methyl methacrylate monomer, adding potassium persulfate initiator, and conducting polymerization reaction under nitrogen protection. After the polymerization reaction is completed, the product is centrifuged and separated, washed with ethanol, and then vacuum-dried at 60-80°C to obtain modified nano-zinc oxide; S3: Antioxidant 1010 was mixed with modified nano zinc oxide and coated with ethyl cellulose to prepare a microcapsule antioxidant.

6. The high RAP content cold mix asphalt rejuvenator according to claim 5, characterized in that: In step S1, the volume ratio of ethanol to water is 1:(8-10), the amount of the silane coupling agent added is (0.5-2%) of the mass of the nano-zinc oxide, the concentration of potassium persulfate in step S2 is 0.5-2%, the temperature during the polymerization reaction is 60-80°C, and the reaction time is 4-6 hours. In step S3, the mass ratio of antioxidant 1010 to modified nano-zinc oxide is (4-6):1, and the particle size of ethyl cellulose is 10-15 μm.

7. The high RAP content cold mix asphalt rejuvenator according to claim 1, characterized in that: The preparation method of the pre-swelling SEBS masterbatch is: Add 5-8% of naphthenic oil to the SEBS masterbatch, stir and react at 80-90°C for 30-60 minutes, and then add 3% of maleic anhydride for grafting to obtain a pre-swollen SEBS masterbatch.

8. The high RAP content cold mix asphalt rejuvenator according to claim 1, characterized in that: The preparation method of the low-temperature penetrant is: A hydrogen peroxide oxidant is added to the weighed branched alkyl sodium sulfonate to convert the terminal alkyl group of the branched alkyl sodium sulfonate into a carboxylic acid group, and then a dicyclohexylcarbodiimide coupling agent and glycidylamine are added, and the reaction is carried out under an inert gas at 0-5°C for 20-60 minutes to obtain a low-temperature penetrant.

9. The method for preparing a high RAP content cold mix asphalt regeneration agent according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Weigh each raw material according to the above weight parts, heat the weighed hydrogenated extracted oil to 65-75℃, add acetyl tributyl citrate plasticizer and stir for 25-35 minutes, add low-temperature penetrant after stirring for 20 minutes; then heat to 85-95℃ and add pre-swollen SEBS masterbatch, then add cross-linking catalyst and carry out cross-linking catalysis for 30 minutes, cool the temperature to 60-70℃ and add microcapsule antioxidant, continue stirring at 60℃ for 20 minutes, and obtain high RAP content cold mix asphalt regeneration agent after cooling to room temperature.

10. The method for preparing a high RAP content cold mix asphalt regeneration agent according to claim 9, characterized in that: The ultrasonic dispersion of the low-temperature penetrant is carried out by adopting an ultrasonic-mechanical blending composite dispersion process, and the ultrasonic power is ≥400W.

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