Regenerated cold patch asphalt mixture and preparation method thereof

Abstract

The invention relates to the technical field of road pit slot repairing, in particular to a recycled cold patch asphalt mixture and a preparation method thereof. The recycled cold patch asphalt mixture is prepared from the following raw materials in parts by mass: 92 to 98 parts of asphalt pavement recycled material, 1 to 3 parts of mineral powder, 0.2 to 1.0 part of basalt fiber and 4 to 8 parts of cold patch asphalt. The cold patch asphalt is prepared from the following raw materials in parts by mass: 85 to 100 parts of matrix asphalt, 30 to 40 parts of compatilizer, 20 to 30 parts of diluent, 25 to 40 parts of modified polyurethane prepolymer, 0.2 to 1.5 parts of anti-rut agent and 0.3 to 3 parts of anti-stripping agent. The regenerated cold patch asphalt mixture prepared by the invention shows excellent comprehensive performance in the aspects of dynamic stability, freeze-thaw resistance, Marshall stability, self-repairing capability and the like, and has good economic and environmental benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of road pothole repair, in particular to a regenerated cold-patch asphalt mixture and a preparation method thereof. Background Art

[0002] With the acceleration of urbanization and the increasing demand for road traffic, asphalt pavement defects are becoming increasingly prominent. Potholes are a common problem on asphalt pavements. If left unrepaired, they not only shorten the pavement's service life but can also pose a serious threat to driving safety. Therefore, timely and effective pothole repair is crucial.

[0003] Recycled cold patch asphalt mix is ​​a mixture of recycled asphalt pavement material (RAP) with new aggregate, regeneration agent, cold patch asphalt, and other materials. This mixture is mixed at room or low temperatures to create a repair solution for potholes and other asphalt pavement defects. Combining recycling and cold patching technologies, it not only achieves resource recycling but also offers the advantages of cold patch asphalt mixes, such as the ease of construction and the lack of heating.

[0004] The strength and durability of recycled cold-patch asphalt mixtures are often lower than those of traditional hot-mix asphalt mixtures. The compatibility issues between aged and new asphalt in RAP, as well as the influence of the amount and type of regeneration agent on the mixture's performance, make the mixture susceptible to defects such as rutting, cracking, and loosening during long-term use. Furthermore, because RAP may contain high levels of moisture and impurities, and the addition of regeneration agents may affect the adhesion between asphalt and aggregate, recycled cold-patch asphalt mixtures have poor water stability, making them prone to flaking and mud pumping in humid environments.

[0005] Therefore, we propose a recycled cold patch asphalt mixture and a preparation method thereof. Summary of the Invention

[0006] The purpose of the present invention is to provide a regenerated cold patch asphalt mixture and a preparation method thereof, so as to solve the problems raised in the prior art.

[0007] To achieve the above object, the present invention provides the following technical solutions: A recycled cold patch asphalt mixture comprises the following raw materials in parts by mass: 92-98 parts of asphalt pavement recycled material, 1-3 parts of mineral powder, 0.2-1.0 parts of basalt fiber, and 4-8 parts of cold patch asphalt.

[0008] Furthermore, the cold patch asphalt includes the following raw materials in parts by mass: 85-100 parts of base asphalt, 30-40 parts of compatibilizer, 20-30 parts of diluent, 25-40 parts of modified polyurethane prepolymer, 0.2-1.5 parts of anti-rutting agent, and 0.3-3 parts of anti-stripping agent.

[0009] Furthermore, the preparation method of the modified polyurethane prepolymer is as follows: Step 1: Under nitrogen protection, heat and melt the acrylic rosin, add butanediol diglycidyl ether under the catalysis of triethylamine, and react at 120-130°C for 6-8 hours to obtain epoxy-terminated rosin; Step 2: Under nitrogen protection, epoxy-terminated rosin and cystamine dihydrochloride are added to a mixed solution of ethanol and tetrahydrofuran, triethylamine is added and mixed evenly, and the mixture is reacted at 40-60° C. for 10-12 hours. After washing and drying, disulfide-modified rosin is obtained; Step 3: uniformly mixing the disulfide bond-modified rosin, the mercapto-containing organosilicon and the photoinitiator, and irradiating the mixture with ultraviolet light to obtain an organosilicon-modified polyol; Step 4: Dehydrate the polyether polyol and silicone-modified polyol in a vacuum at 110-120° C. for 2-3 hours, cool to 60-70° C., add isophorone diisocyanate and dibutyltin dilaurate under nitrogen protection, mix evenly, react for 1-3 hours, add 2,2-dihydroxymethylbutyric acid, and react for 2-4 hours to obtain a modified polyurethane prepolymer.

[0010] Furthermore, in step 1, the molar ratio of acrylic rosin to butanediol diglycidyl ether is 1:2.

[0011] Furthermore, in step 1, the amount of triethylamine used is 1 to 3% of the total mass of acrylic rosin and butanediol diglycidyl ether.

[0012] Furthermore, in step 2, the molar ratio of epoxy-terminated rosin to cystamine dihydrochloride is 1:(1-2).

[0013] Furthermore, in step 2, the amount of triethylamine used is 3-5% of the total mass of the epoxy-terminated rosin and cystamine dihydrochloride.

[0014] Furthermore, in the mixed solution, the mass ratio of ethanol to tetrahydrofuran is 1:1.

[0015] Furthermore, in step 3, the mass ratio of the disulfide bond-modified rosin, the mercapto-containing silicone and the photoinitiator is 1: (0.3-0.5): (0.1-0.3).

[0016] Furthermore, the photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0017] Furthermore, the process conditions of the ultraviolet irradiation are: irradiation with 360-400 nm ultraviolet light for 30-60 min, irradiation intensity of 25-35 mW / cm 2 .

[0018] Furthermore, the preparation method of the mercapto-containing organosilicon is as follows: under nitrogen protection, 3-mercaptopropylmethyldimethoxysilane, deionized water and isopropyl alcohol are evenly mixed, hydroxy silicone oil and tetramethylammonium hydroxide are added, and the mixture is reacted at 60-70° C. for 4-6 hours, and the mercapto-containing organosilicon is obtained by vacuum distillation.

[0019] Furthermore, the mass ratio of the 3-mercaptopropylmethyldimethoxysilane, deionized water, isopropyl alcohol, hydroxy silicone oil and tetramethylammonium hydroxide is 1: (2-3): (6-8): (64-66): (1.2-1.4).

[0020] Furthermore, the modified polyurethane prepolymer comprises the following raw materials in parts by mass: 40-50 parts of polyether polyol, 10-20 parts of silicone modified polyol, 70-90 parts of isophorone diisocyanate, 1-3 parts of dibutyltin dilaurate, and 2-4 parts of 2,2-dihydroxymethylbutyric acid.

[0021] Furthermore, the compatibilizer is maleic anhydride.

[0022] Furthermore, the diluent is a mixture of one or more of kerosene, diesel and gasoline.

[0023] Furthermore, the anti-stripping agent is vinyl bisstearamide.

[0024] A method for preparing a regenerated cold patch asphalt mixture comprises the following steps: Step S1: heating the base asphalt to 130-150°C, adding a compatibilizer, stirring for 5-10 minutes, then adding a modified polyurethane prepolymer, stirring for 30-40 minutes, then adding a diluent, an anti-rutting agent, and an anti-stripping agent, stirring evenly until the temperature drops to 80-90°C to obtain a cold patch asphalt; Step S2: Heat the recycled asphalt pavement material to 70-80° C., add the cold patch asphalt prepared in step S1, stir for 90-120 seconds, add mineral powder and basalt fiber, and stir again for 90-120 seconds to obtain a recycled cold patch asphalt mixture.

[0025] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention relates to a regenerated cold-patch asphalt mixture and its preparation method. By reacting acrylic rosin with butanediol diglycidyl ether, a cyclic terpene structure is introduced, which provides rigidity and heat resistance, thereby obtaining epoxy-terminated rosin. Cystamine dihydrochloride is used to react with epoxy groups to introduce dynamic disulfide bonds, thereby obtaining disulfide-modified rosin. This imparts excellent self-repairing properties to the polyurethane. The self-repairing mechanism of the dynamic disulfide bonds promotes the inherent self-repairing ability of asphalt, achieving synergistic repair. In the scheme, in order to improve the water resistance and toughness of polyurethane, hydroxyl groups are introduced by hydrolyzing 3-mercaptopropylmethyldimethoxysilane and then dehydrating and condensing it with hydroxyl silicone oil to obtain mercapto-containing silicone; the silicone chain segments are introduced into the disulfide bond modified rosin by utilizing the mercapto-ene click reaction to improve the water resistance of the material and effectively block water erosion. At the same time, the silanol groups in the silicone can form a stronger connection with the surface of inorganic materials such as aggregates and the cement matrix of the pavement, effectively enhancing the curing strength of the cold patch asphalt system and greatly improving the interfacial adhesion between the cold patch material and the roadbed; the dynamic disulfide bonds work synergistically with the silicone segments to enhance the shear resistance while ensuring that the material maintains structural integrity under extreme environments such as high pressure, humidity and heat, solving the technical bottleneck of traditional cold patch materials that are easy to loosen and peel off.

[0026] 2. The present invention relates to a regenerated cold-patch asphalt mixture and its preparation method. The introduction of a polyurethane prepolymer significantly improves the cohesive properties of the cold-patch material, resulting in a stronger bond between the cold-patch material and the pothole interface. This strong bond effectively prevents the asphalt mixture from becoming loose or breaking at the joints prematurely after filling the pothole, thereby significantly improving the durability of the cold-patch material. After the polyurethane prepolymer is fully mixed with the liquid asphalt and solidifies, the asphalt is evenly distributed in the spatial network structure formed by the polyurethane prepolymer. This not only increases the strength of the cold-patch material, but also ensures that the cold-patch material will not become sticky or soften under high temperature conditions, thereby meeting the requirements for use in high-temperature climates and further improving durability. DETAILED DESCRIPTION

[0027] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0028] In this embodiment, the recycled asphalt pavement material is taken from the milling material of a certain highway and is ground to meet the technical requirements specified in the "Technical Specifications for Regeneration of Highway Asphalt Pavement" (JTG / T5521-2019); matrix asphalt: 70# road petroleum asphalt; basalt fiber: length 6 mm, monofilament diameter 15 μm, sourced from Tai'an Songze Composite Materials Co., Ltd.; mineral powder: grade S95; diluent: 0# diesel; anti-rutting agent: model KCCJ001, sourced from Changzhou Bochao Engineering Materials Co., Ltd.; anti-stripping agent: vinyl bisstearamide; polyether polyol: brand CP450, sourced from Dow Chemical; hydroxyl silicone oil: viscosity of 70 mPa·s at 25°C, hydroxyl content of 3%, sourced from Shenzhen Jipeng Silicone Fluorine Materials Co., Ltd.

[0029] The following parts are by mass unless otherwise specified.

[0030] Example 1: A method for preparing a regenerated cold patch asphalt mixture, comprising the following process: Step S1: Heat 85 parts of base asphalt to 130°C, add 30 parts of compatibilizer, stir for 5 minutes, then add 25 parts of modified polyurethane prepolymer, stir for 30 minutes, then add 20 parts of diluent, 0.2 parts of anti-rutting agent and 0.3 parts of anti-stripping agent, stir evenly until the temperature drops to 80°C to obtain cold patch asphalt; Step S2: Heat 92 parts of recycled asphalt pavement material to 70°C, add 4 parts of the cold patch asphalt prepared in step S1, stir for 90 seconds, then add 1 part of mineral powder and 0.2 parts of basalt fiber, and stir again for 90 seconds to obtain a recycled cold patch asphalt mixture; The preparation method of the modified polyurethane prepolymer is as follows: Step 1: Under nitrogen protection, heat and melt the acrylic rosin, add butanediol diglycidyl ether under the catalysis of triethylamine, and react at 120°C for 6 hours to obtain epoxy-terminated rosin; the molar ratio of acrylic rosin to butanediol diglycidyl ether is 1:2; the amount of triethylamine used is 1% of the total mass of acrylic rosin and butanediol diglycidyl ether; Step 2: Under nitrogen protection, epoxy-terminated rosin and cystamine dihydrochloride are dissolved in a mixed solution of ethanol and tetrahydrofuran in a mass ratio of 1:1, triethylamine is added and mixed evenly, and the mixture is reacted at 40°C for 10 hours. After washing and drying, disulfide-modified rosin is obtained; the molar ratio of epoxy-terminated rosin and cystamine dihydrochloride is 1:1; and the amount of triethylamine used is 3% of the total mass of the epoxy-terminated rosin and cystamine dihydrochloride; Step 3: Under nitrogen protection, 0.2 parts of 3-mercaptopropylmethyldimethoxysilane, 0.4 parts of deionized water and 1.2 parts of isopropyl alcohol were mixed evenly, 12.8 parts of hydroxy silicone oil and 0.24 parts of tetramethylammonium hydroxide were added, and the mixture was reacted at 60°C for 4 hours, and then distilled under reduced pressure to obtain a mercapto-containing organosilicon; 10 parts of disulfide bond modified rosin, 3 parts of mercapto-containing silicone and 1 part of 2-hydroxy-2-methyl-1-phenyl-1-propanone were mixed evenly and irradiated with 360nm ultraviolet light for 30 minutes with an irradiation intensity of 35mW / cm 2 , obtaining organosilicon-modified polyol; Step 4: Dehydrate 40 parts of polyether polyol and 10 parts of silicone-modified polyol under vacuum at 110°C for 2 hours, cool to 60°C, add 70 parts of isophorone diisocyanate and 1 part of dibutyltin dilaurate under nitrogen protection, mix evenly, react for 1 hour, add 2 parts of 2,2-dihydroxymethylbutyric acid, and react for 2 hours to obtain a modified polyurethane prepolymer.

[0031] Example 2: A method for preparing a regenerated cold patch asphalt mixture, comprising the following process: Step S1: Heat 90 parts of base asphalt to 140°C, add 35 parts of compatibilizer, stir for 8 minutes, then add 35 parts of modified polyurethane prepolymer, stir for 35 minutes, then add 25 parts of diluent, 1 part of anti-rutting agent and 2 parts of anti-stripping agent, stir evenly until the temperature drops to 85°C to obtain cold patch asphalt; Step S2: 96 parts of recycled asphalt pavement material were heated to 75°C, 6 parts of the cold patch asphalt prepared in step S1 were added, and the mixture was stirred for 100 seconds. 2 parts of mineral powder and 0.8 parts of basalt fiber were added, and the mixture was stirred again for 100 seconds to obtain a recycled cold patch asphalt mixture. The preparation method of the modified polyurethane prepolymer is as follows: Step 1: Under nitrogen protection, heat and melt the acrylic rosin, add butanediol diglycidyl ether under the catalysis of triethylamine, and react at 125°C for 7 hours to obtain epoxy-terminated rosin; the molar ratio of acrylic rosin to butanediol diglycidyl ether is 1:2; the amount of triethylamine used is 2% of the total mass of acrylic rosin and butanediol diglycidyl ether; Step 2: Under nitrogen protection, epoxy-terminated rosin and cystamine dihydrochloride are dissolved in a mixed solution of ethanol and tetrahydrofuran in a mass ratio of 1:1, triethylamine is added and mixed evenly, and the mixture is reacted at 50°C for 11 hours. After washing and drying, disulfide-modified rosin is obtained; the molar ratio of epoxy-terminated rosin and cystamine dihydrochloride is 1:1.5; the amount of triethylamine used is 4% of the total mass of the epoxy-terminated rosin and cystamine dihydrochloride; Step 3: Under nitrogen protection, 0.2 parts of 3-mercaptopropylmethyldimethoxysilane, 0.5 parts of deionized water and 1.4 parts of isopropyl alcohol were mixed evenly, 13 parts of hydroxy silicone oil and 0.26 parts of tetramethylammonium hydroxide were added, and the mixture was reacted at 65°C for 5 hours, and then distilled under reduced pressure to obtain a mercapto-containing organosilicon; 15 parts of disulfide bond modified rosin, 6 parts of mercapto-containing silicone and 3 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone were mixed evenly and irradiated with 380nm ultraviolet light for 40 minutes with an irradiation intensity of 30mW / cm 2 , obtaining organosilicon-modified polyol; Step 4: Dehydrate 45 parts of polyether polyol and 15 parts of silicone-modified polyol under vacuum at 115°C for 2.5 hours, cool to 65°C, add 80 parts of isophorone diisocyanate and 2 parts of dibutyltin dilaurate under nitrogen protection, mix evenly, react for 2 hours, add 3 parts of 2,2-dihydroxymethylbutyric acid, and react for 3 hours to obtain a modified polyurethane prepolymer.

[0032] Example 3: A method for preparing a regenerated cold patch asphalt mixture, comprising the following process: Step S1: Heat 100 parts of base asphalt to 150°C, add 40 parts of compatibilizer, stir for 10 minutes, then add 40 parts of modified polyurethane prepolymer, stir for 40 minutes, then add 30 parts of diluent, 1.5 parts of anti-rutting agent and 3 parts of anti-stripping agent, stir evenly until the temperature drops to 90°C to obtain cold patch asphalt; Step S2: Heat 98 parts of recycled asphalt pavement material to 80°C, add 8 parts of the cold patch asphalt prepared in step S1, stir for 120 seconds, add 3 parts of mineral powder and 1.0 part of basalt fiber, and stir again for 120 seconds to obtain a recycled cold patch asphalt mixture; The preparation method of the modified polyurethane prepolymer is as follows: Step 1: Under nitrogen protection, heat and melt the acrylic rosin, add butanediol diglycidyl ether under the catalysis of triethylamine, and react at 130°C for 8 hours to obtain epoxy-terminated rosin; the molar ratio of acrylic rosin to butanediol diglycidyl ether is 1:2; the amount of triethylamine used is 3% of the total mass of acrylic rosin and butanediol diglycidyl ether; Step 2: Under nitrogen protection, epoxy-terminated rosin and cystamine dihydrochloride are dissolved in a mixed solution of ethanol and tetrahydrofuran in a mass ratio of 1:1, triethylamine is added and mixed evenly, and the mixture is reacted at 60°C for 12 hours. After washing and drying, disulfide-modified rosin is obtained; the molar ratio of epoxy-terminated rosin and cystamine dihydrochloride is 1:2; and the amount of triethylamine used is 5% of the total mass of the epoxy-terminated rosin and cystamine dihydrochloride; Step 3: Under nitrogen protection, 0.2 parts of 3-mercaptopropylmethyldimethoxysilane, 0.6 parts of deionized water and 1.6 parts of isopropyl alcohol were mixed evenly, 13.2 parts of hydroxy silicone oil and 0.28 parts of tetramethylammonium hydroxide were added, and the mixture was reacted at 70°C for 6 hours, and then distilled under reduced pressure to obtain a mercapto-containing organosilicon; 20 parts of disulfide bond modified rosin, 10 parts of mercapto-containing silicone and 6 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone were mixed evenly and irradiated with 400 nm ultraviolet light for 60 min at an irradiation intensity of 25 mW / cm 2 , obtaining organosilicon-modified polyol; Step 4: Dehydrate 50 parts of polyether polyol and 20 parts of silicone-modified polyol under vacuum at 120°C for 3 hours, cool to 70°C, add 90 parts of isophorone diisocyanate and 3 parts of dibutyltin dilaurate under nitrogen protection, mix evenly, react for 3 hours, add 4 parts of 2,2-dihydroxymethylbutyric acid, and react for 4 hours to obtain a modified polyurethane prepolymer.

[0033] Comparative Example 1: A method for preparing a recycled cold-patch asphalt mixture, comprising the following processes: Compared with Example 2, in Comparative Example 1, the organosilicon-modified polyol was replaced with epoxy-terminated rosin of the same mass, and the other steps were the same as those in Example 2.

[0034] Comparative Example 2: A method for preparing a recycled cold-patch asphalt mixture, comprising the following processes: The preparation method of the modified polyurethane prepolymer is as follows: Step 1: Under nitrogen protection, heat and melt the acrylic rosin, add butanediol diglycidyl ether under the catalysis of triethylamine, and react at 125°C for 7 hours to obtain epoxy-terminated rosin; the molar ratio of acrylic rosin to butanediol diglycidyl ether is 1:2; the amount of triethylamine used is 2% of the total mass of acrylic rosin and butanediol diglycidyl ether; Step 2: Under nitrogen protection, 0.2 parts of 3-mercaptopropylmethyldimethoxysilane, 0.5 parts of deionized water and 1.4 parts of isopropyl alcohol were mixed evenly, 13 parts of hydroxy silicone oil and 0.26 parts of tetramethylammonium hydroxide were added, and the mixture was reacted at 65°C for 5 hours, and then distilled under reduced pressure to obtain a mercapto-containing organosilicon; 15 parts of epoxy-terminated rosin, 6 parts of mercapto-containing silicone and 3 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone were mixed evenly and irradiated with 380nm ultraviolet light for 40 minutes with an irradiation intensity of 30mW / cm 2 , obtaining organosilicon-modified polyol; Step 3: 45 parts of polyether polyol and 15 parts of silicone-modified polyol were vacuum dehydrated at 115°C for 2.5 hours, cooled to 65°C, and under nitrogen protection, 80 parts of isophorone diisocyanate and 2 parts of dibutyltin dilaurate were added and mixed evenly, reacted for 2 hours, and 3 parts of 2,2-dihydroxymethylbutyric acid were added and reacted for 3 hours to obtain a modified polyurethane prepolymer; Compared with Example 2, Comparative Example 2 does not introduce cystamine dihydrochloride, and replaces the disulfide bond-modified rosin with epoxy-terminated rosin. Other steps are the same as those in Example 2.

[0035] Comparative Example 3: A method for preparing a recycled cold-patch asphalt mixture, comprising the following processes: The preparation method of the modified polyurethane prepolymer is as follows: Step 1: Under nitrogen protection, heat and melt the acrylic rosin, add butanediol diglycidyl ether under the catalysis of triethylamine, and react at 125°C for 7 hours to obtain epoxy-terminated rosin; the molar ratio of acrylic rosin to butanediol diglycidyl ether is 1:2; the amount of triethylamine used is 2% of the total mass of acrylic rosin and butanediol diglycidyl ether; Step 2: Under nitrogen protection, epoxy-terminated rosin and cystamine dihydrochloride are dissolved in a mixed solution of ethanol and tetrahydrofuran in a mass ratio of 1:1, triethylamine is added and mixed evenly, and the mixture is reacted at 50°C for 11 hours. After washing and drying, disulfide-modified rosin is obtained; the molar ratio of epoxy-terminated rosin and cystamine dihydrochloride is 1:1.5; the amount of triethylamine used is 4% of the total mass of the epoxy-terminated rosin and cystamine dihydrochloride; Step 3: Dehydrate 45 parts of polyether polyol and 15 parts of disulfide bond-modified rosin under vacuum at 115°C for 2.5 hours, cool to 65°C, add 80 parts of isophorone diisocyanate and 2 parts of dibutyltin dilaurate under nitrogen protection, mix evenly, react for 2 hours, add 3 parts of 2,2-dihydroxymethylbutyric acid, and react for 3 hours to obtain a modified polyurethane prepolymer.

[0036] Compared with Example 2, Comparative Example 3 does not introduce mercapto-containing organosilicon, and replaces the organosilicon-modified polyol with disulfide bond-modified rosin. Other steps are the same as those in Example 2.

[0037] experiment: 1. Dynamic stability test: The recycled cold patch asphalt mixtures obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were tested in accordance with JTG E20-2011. The specimen size was 300 mm × 300 mm × 50 mm. The test temperature was 60°C. The loading wheel was rolled back and forth at a frequency of 42 times / min and a pressure of 0.7 MPa for 60 minutes. 2. Freeze-thaw splitting strength ratio test: The regenerated cold patch asphalt mixtures obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were subjected to freeze-thaw cycles under the conditions specified in JTG E20-2011 to determine the splitting strength ratio of the specimens before and after water damage, thereby evaluating the water stability of the asphalt mixture. The test temperature was 25°C and the loading rate was 50 mm / min.

[0038] 3. Marshall stability test: Take the recycled cold patch asphalt mixture obtained in Examples 1 to 3 and Comparative Examples 1 to 3, with a Marshall specimen size of Φ101.6 mm × 63.5 mm, place it in a test mold at room temperature, compact it 75 times on both sides at -5°C, demold it, and perform a Marshall strength test in accordance with the provisions of JTGE20-2011, and record the data.

[0039] 4. Self-Healing Performance Test: The cold-patch asphalt obtained in Examples 1-3 and Comparative Examples 1-3 was tested using a fracture-repair-fracture test to evaluate its self-healing ability for macrocracks. The specimens were divided into two groups: Group 1 consisted of uncut specimens, for which a ductility test was immediately performed at 10°C. The ductility data for this group was recorded as L1. Group 2 consisted of crack-cut specimens. A crack of a certain depth was cut in the center of the specimen, leaving a depth of 4.5 mm uncut. After 8 hours at 25°C, the specimens were tested at 10°C for ductility. The ductility data for this group was recorded as L2. The self-healing efficiency was calculated as L2 / L1 × 100%.

[0040] The test results are as follows:

[0041] According to the data in the above table, we can clearly draw the following conclusions: Combining Examples 1-3 with Comparative Examples 1-3, it can be seen that the recycled cold-patch asphalt mixture prepared by the present invention exhibits excellent overall performance in terms of dynamic stability, freeze-thaw resistance, Marshall stability, and self-repair ability, with good economic and environmental benefits. This material not only effectively extends the service life of roads and reduces maintenance frequency, thereby lowering maintenance costs, but also reduces resource waste and environmental pollution by recycling waste asphalt materials, in line with the concept of sustainable development.

[0042] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A recycled cold patch asphalt mixture, characterized by: The invention comprises the following raw materials in parts by weight: 92 to 98 parts of asphalt pavement recycled materials, 1 to 3 parts of mineral powder, 0.2 to 1.0 parts of basalt fiber and 4 to 8 parts of cold patch asphalt.

2. The regenerated cold patch asphalt mixture according to claim 1, characterized in that: The cold patch asphalt includes the following raw materials in parts by mass: 85-100 parts of base asphalt, 30-40 parts of compatibilizer, 20-30 parts of diluent, 25-40 parts of modified polyurethane prepolymer, 0.2-1.5 parts of anti-rutting agent, and 0.3-3 parts of anti-stripping agent.

3. The regenerated cold patch asphalt mixture according to claim 2, characterized in that: The preparation method of the modified polyurethane prepolymer is as follows: Step 1: Under nitrogen protection, heat and melt the acrylic rosin, add butanediol diglycidyl ether under the catalysis of triethylamine, and react at 120-130°C for 6-8 hours to obtain epoxy-terminated rosin; Step 2: Under nitrogen protection, epoxy-terminated rosin and cystamine dihydrochloride are added to a mixed solution of ethanol and tetrahydrofuran, triethylamine is added and mixed evenly, and the mixture is reacted at 40-60° C. for 10-12 hours. After washing and drying, disulfide-modified rosin is obtained; Step 3: uniformly mixing the disulfide bond-modified rosin, the mercapto-containing organosilicon and the photoinitiator, and irradiating the mixture with ultraviolet light to obtain an organosilicon-modified polyol; Step 4: Dehydrate the polyether polyol and silicone-modified polyol in a vacuum at 110-120° C. for 2-3 hours, cool to 60-70° C., add isophorone diisocyanate and dibutyltin dilaurate under nitrogen protection, mix evenly, react for 1-3 hours, add 2,2-dihydroxymethylbutyric acid, and react for 2-4 hours to obtain a modified polyurethane prepolymer.

4. The regenerated cold patch asphalt mixture according to claim 3, characterized in that: In step 1, the molar ratio of acrylic rosin to butanediol diglycidyl ether is 1:

2.

5. The regenerated cold patch asphalt mixture according to claim 3, characterized in that: In step 2, the molar ratio of epoxy-terminated rosin to cystamine dihydrochloride is 1:(1-2).

6. The regenerated cold patch asphalt mixture according to claim 3, characterized in that: In step 3, the mass ratio of disulfide bond-modified rosin, mercapto-containing silicone and photoinitiator is 1: (0.3-0.5): (0.1-0.3).

7. The regenerated cold patch asphalt mixture according to claim 6, characterized in that: The preparation method of the mercapto-containing organosilicon is as follows: under nitrogen protection, 3-mercaptopropylmethyldimethoxysilane, deionized water and isopropyl alcohol are uniformly mixed, hydroxy silicone oil and tetramethylammonium hydroxide are added, and the mixture is reacted at 60-70° C. for 4-6 hours, and the mercapto-containing organosilicon is obtained by vacuum distillation.

8. The regenerated cold patch asphalt mixture according to claim 3, characterized in that: The modified polyurethane prepolymer comprises the following raw materials in parts by mass: 40-50 parts of polyether polyol, 10-20 parts of organosilicon-modified polyol, 70-90 parts of isophorone diisocyanate, 1-3 parts of dibutyltin dilaurate, and 2-4 parts of 2,2-dihydroxymethylbutyric acid.

9. The regenerated cold patch asphalt mixture according to claim 2, characterized in that: The diluent is a mixture of one or more of kerosene, diesel and gasoline.

10. The method for preparing a regenerated cold patch asphalt mixture according to any one of claims 1 to 9, characterized in that: The steps include: Step S1: heating the base asphalt to 130-150°C, adding a compatibilizer, stirring for 5-10 minutes, then adding a modified polyurethane prepolymer, stirring for 30-40 minutes, then adding a diluent, an anti-rutting agent, and an anti-stripping agent, stirring evenly until the temperature drops to 80-90°C to obtain a cold patch asphalt; Step S2: Heat the recycled asphalt pavement material to 70-80° C., add the cold patch asphalt prepared in step S1, stir for 90-120 seconds, then add the mineral powder and basalt fiber, and stir again for 90-120 seconds to obtain a recycled cold patch asphalt mixture.

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