A recycled asphalt mixture with good durability and a method of making the same

Abstract

This invention relates to the field of recycled asphalt mixture technology, specifically disclosing a durable recycled asphalt mixture and its preparation method. A durable recycled asphalt mixture comprises 60-80 parts of recycled waste asphalt mixture, 4-7 parts of new asphalt, 15-18 parts of new aggregate, 2-5 parts of fiber, 3-7 parts of rejuvenating agent, and 2-5 parts of filler; wherein the rejuvenating agent includes aromatic oil, triethylene glycol diisooctanoate, 2-ethylhexyl diphenyl phosphate, dioctyl terephthalate, epoxidized soybean oil, dipropylene glycol methyl ether acetate, polymethylene polyphenyl polyisocyanate, oleic acid-based hydroxyethyl imidazoline, 0-erucamide, and barium petroleum sulfonate. The recycled asphalt mixture provided by this application can effectively resist the formation of rutting, cracking, and other defects, significantly extending the service life of roads and reducing road maintenance costs.

Description

Technical Field

[0001] This invention relates to the field of recycled asphalt mixture technology, and in particular to a durable recycled asphalt mixture and its preparation method. Background Technology

[0002] In recent years, with the continuous development of society, more and more old asphalt roads are facing renovation or reconstruction, which will inevitably generate a large amount of waste asphalt mixture (RAP). Therefore, the recycling of waste asphalt mixture has gradually become a key research direction in the field of road engineering.

[0003] Because waste asphalt mixtures undergo aging processes such as oxidation, moisture penetration, and impurity erosion during long-term service, they become hard and brittle, with significantly reduced bonding properties and elasticity, making them difficult to reuse directly in road construction. However, discarding waste asphalt mixtures directly would also result in a huge waste of resources.

[0004] Currently, although there are some methods for recycling waste asphalt mixtures, the recycled asphalt mixtures prepared by these methods often fail to achieve ideal durability. Such recycled asphalt mixtures are prone to rutting, cracking, and other defects during use, significantly shortening the service life of roads and increasing maintenance costs. Therefore, developing a durable recycled asphalt mixture and its preparation method is of significant practical importance. Summary of the Invention

[0005] To improve the durability of recycled asphalt mixtures, this application provides a durable recycled asphalt mixture and its preparation method.

[0006] The recycled asphalt mixture provided in this application uses recycled waste asphalt mixture as the base material. By introducing a specific recycling agent, the adhesion and elasticity of the recycled asphalt mixture are significantly improved, and its resistance to deformation is enhanced. Through the synergistic effect of the other raw materials, the recycled asphalt mixture provided in this application can effectively resist the occurrence of rutting, cracking and other diseases, significantly extend the service life of the road, reduce the road maintenance cost, and has good economic and social benefits.

[0007] Firstly, the durable recycled asphalt mixture provided in this application adopts the following technical solution:

[0008] A durable recycled asphalt mixture comprises the following raw materials in parts by weight: 60-80 parts of waste asphalt mixture recycled material, 4-7 parts of new asphalt, 15-18 parts of new aggregate, 2-5 parts of fiber, 3-7 parts of recycling agent, and 2-5 parts of filler.

[0009] Based on the mass fractions of the regenerant, the regenerant comprises 50-70 parts aromatic oil, 10-20 parts triethylene glycol diisooctanoate, 5-8 parts 2-ethylhexyl diphenyl phosphate, 5-8 parts dioctyl terephthalate, 3-5 parts epoxidized soybean oil, 3-5 parts dipropylene glycol methyl ether acetate, 3-5 parts polymethylene polyphenyl polyisocyanate, 1-3 parts oleic acid-based hydroxyethyl imidazoline, 0.5-2 parts erucamide, and 0.5-2 parts barium petroleum sulfonate.

[0010] In the above technical solution, this application mixes waste asphalt with recycled material and new asphalt, and introduces a specific ratio of recycling agent, so that the molecules of the new and old asphalt can achieve full diffusion and entanglement at the microscopic level. By introducing fibers, the bonding strength between the new and old asphalt and aggregates in the recycled asphalt mixture is improved, effectively preventing the generation and propagation of cracks. Through the combined action of recycling agent, fibers, new aggregates and fillers, the durability of the recycled asphalt mixture is significantly improved.

[0011] Furthermore, this application utilizes a specific recycler formulation, particularly by creatively combining polymethylene polyphenyl isocyanate, oleic acid-based hydroxyethyl imidazoline, erucamide, and barium petroleum sulfonate in the recycler. Through the synergistic effect of these raw materials, the recycler can better penetrate into the waste asphalt mixture recycling material, thereby achieving effective regeneration of aged asphalt. Specifically, aromatic oil, triethylene glycol diisooctanoate, 2-ethylhexyl diphenyl phosphate, and dioctyl terephthalate are the main components of the regenerator, which have a good effect on softening aged asphalt and can effectively restore the flexibility and adhesion of the recycled asphalt. Epoxidized soybean oil and dipropylene glycol methyl ether acetate play a plasticizing and toughening role, further improving the elasticity and deformation resistance of the recycled asphalt. The addition of polymethylene polyphenyl polyisocyanate, oleic acid-based hydroxyethyl imidazoline, erucamide, and barium petroleum sulfonate further improves the permeability of the regenerator to waste asphalt, effectively enhances the wettability of new and old asphalt to aggregates, and promotes the molecular fusion between new and waste asphalt. This effectively prevents cracks and rutting caused by the separation of the new and old asphalt interface during the use of recycled asphalt mixtures, and significantly improves the durability of recycled asphalt mixtures.

[0012] Preferably, the method for preparing the regenerant includes the following steps:

[0013] Step 1: Add aromatic oil to the reaction vessel and heat it to 80~85℃ while stirring.

[0014] Step 2: While stirring, add triethylene glycol diisooctanoate, 2-ethylhexyl diphenyl phosphate, dioctyl terephthalate, epoxidized soybean oil, dipropylene glycol methyl ether acetate, polymethylene polyphenyl polyisocyanate, and oleic acid-based hydroxyethyl imidazoline in sequence, and continue stirring until evenly mixed.

[0015] Step 3: While stirring, slowly add erucamide and barium petroleum sulfonate, and homogenize until evenly mixed.

[0016] Step 4: Turn on the vacuum pump and dehydrate at a vacuum of -0.08 to -0.095 MPa and a temperature of 80 to 90°C for 30 to 40 minutes to obtain the regenerant.

[0017] Preferably, based on the mass fractions of the regenerant, the regenerant comprises 60 parts aromatic oil, 15 parts triethylene glycol diisooctanoate, 6 parts 2-ethylhexyl diphenyl phosphate, 8 parts dioctyl terephthalate, 5 parts epoxidized soybean oil, 4 parts dipropylene glycol methyl ether acetate, 4 parts polymethylene polyphenyl polyisocyanate, 2 parts oleic acid-based hydroxyethyl imidazoline, 1 part erucamide, and 1 part barium petroleum sulfonate.

[0018] In the above technical solution, by using the above-mentioned specific ratio of recycling agent raw materials, the components can exert the best synergistic effect, thereby effectively preventing the occurrence of defects such as cracks and ruts, and significantly improving the durability of recycled asphalt mixture.

[0019] Preferably, the fiber is coconut shell fiber.

[0020] Preferably, the method for preparing the coconut shell fiber includes the following steps:

[0021] Step s1: Take a fresh coconut shell, wash it clean, and then break it into small pieces.

[0022] Step s2: Remove the fragments and soak them in a 10wt% sodium hydroxide aqueous solution, then cook them at a pressure of 0.1~0.3MPa and a temperature of 80~100℃ for 3~4 hours.

[0023] Step s3: Remove the fragments, clean them, and dry them to a constant weight.

[0024] Step s4: Remove the fragments, crush them, and screen out fibers of 0.1~0.5mm.

[0025] Step s5: Spray the modified solution evenly on the fiber surface until the fiber is completely wetted, wherein the modified solution is a mixture of polyaluminum sulfate, diallyl dimethyl ammonium chloride, sodium cocoyl glutamate and water in a mass ratio of (3~5):(0.5~2):(1~3):100.

[0026] Step s6: After drying again, the desired coconut shell fiber is obtained.

[0027] Preferably, the modified solution is prepared by mixing polyaluminum sulfate, diallyl dimethyl ammonium chloride, sodium cocoyl glutamate and water in a mass ratio of 4:1:2:100.

[0028] In the above technical solution, the surface properties of coconut shell fibers are significantly improved after treatment with the modified solution, enhancing their adhesion to asphalt. This enhanced adhesion allows the coconut shell fibers to disperse better in recycled asphalt mixtures and form a stable structure with the asphalt, thereby effectively improving the durability and anti-aging properties of the recycled asphalt mixtures. Specifically, polyaluminum sulfate and diallyl dimethyl ammonium chloride work together on the surface of the coconut shell fibers, reacting with active groups such as hydroxyl groups on the fiber surface to form chemical bonds. This constructs a hard and dense cross-linked network on the fiber surface, enhancing the surface roughness of the fibers and further strengthening the interfacial forces between the fibers and asphalt. Sodium cocoyl glutamate further acts on the fiber surface, not only preventing fiber aggregation and entanglement but also enhancing the wettability between the fibers and asphalt, thereby improving the dispersion of the fibers in the asphalt. Polyaluminum sulfate, diallyl dimethyl ammonium chloride, and sodium cocoyl glutamate work synergistically on the surface of coconut shell fibers, enabling the coconut shell fibers to be better dispersed, adhered, and stabilized in recycled asphalt mixtures. This optimizes the performance of the asphalt mixtures and further improves their durability and anti-aging properties.

[0029] Preferably, the filler is a mixture of limestone powder and silica fume in a mass ratio of (3~5):(1~2).

[0030] In the above technical solution, limestone powder has a large specific surface area and good adsorption performance, while silica fume has good chemical reactivity. This application uses limestone powder and silica fume mixed in a specific ratio as fillers to achieve a synergistic effect and further improve the durability of recycled asphalt mixture.

[0031] Preferably, the new aggregate is a mixture of limestone with a particle size of 0.45~3mm, limestone with a particle size of 5~10mm and limestone with a particle size of 10~15mm in a mass ratio of (5~6):(6~8):(4~5).

[0032] In the above technical solution, this application further improves the durability of recycled asphalt mixture by using limestone of different particle sizes as new aggregates. This allows the recycled asphalt mixture to have a denser skeleton structure.

[0033] Preferably, the waste asphalt mixture is a mixture of RAP with particle sizes of 0-11mm, 11-17mm and 17-22mm in a mass ratio of (1-2):(1-2):(1.5-2.5).

[0034] In the above technical solution, this application optimizes the RAP particle size combination, so that the recycled asphalt mixture can better achieve the fusion of new and old asphalt during the mixing process, forming a uniform and stable structure, thereby further improving the durability of the recycled asphalt mixture.

[0035] Secondly, this application provides a method for preparing a recycled asphalt mixture with good durability, using the following technical solution:

[0036] A method for preparing a durable recycled asphalt mixture includes the following steps:

[0037] Step 1: Add new asphalt, new aggregates, and fillers to mixing pot 1, heat to 150~160℃, mix thoroughly, and keep warm for later use.

[0038] Step 2: Add the recycled waste asphalt mixture to mixing pot 2, preheat to 105~110℃, and mix while spraying the recycling agent until fully mixed.

[0039] Step 3: At 105~110℃, add the material obtained in Step 1 to the material obtained in Step 2, and add the fiber while mixing until fully mixed to obtain a recycled asphalt mixture with good durability.

[0040] In the above technical solution, this application ensures the full mixing and fusion of each component by mixing new and old asphalt in stages, thus ensuring the preparation of recycled asphalt mixture with long-term durability.

[0041] In summary, this application includes at least one of the following beneficial technical effects:

[0042] 1. This application introduces a recycling agent with a specific ratio, which achieves full diffusion and entanglement between new and old asphalt molecules, significantly improving the adhesion and elasticity of recycled asphalt mixtures, significantly improving the durability of recycled asphalt mixtures, extending the service life of roads, and reducing maintenance costs, thus having good economic and social benefits.

[0043] 2. This application improves the durability and anti-aging properties of recycled asphalt mixtures by adding coconut shell fiber to the recycled asphalt mixture and modifying the coconut shell fiber with polyaluminum sulfate and diallyl dimethyl ammonium chloride. Detailed Implementation

[0044] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0045] Preparation Example 1

[0046] A recycled asphalt mixture, comprising:

[0047] Damaged RAP was milled from a section of highway, crushed by a crusher, and then screened to obtain RAP with particle sizes of 0~11mm, 11~17mm and 17~22mm.

[0048] Preparation Example 2

[0049] A regenerator comprises 50g aromatic oil, 20g triethylene glycol diisooctanoate, 8g 2-ethylhexyl diphenyl phosphate, 5g dioctyl terephthalate, 3g epoxidized soybean oil, 5g dipropylene glycol methyl ether acetate, 3g polymethylene polyphenyl polyisocyanate, 3g oleic acid-based hydroxyethyl imidazoline, 2g erucamide, and 0.5g barium petroleum sulfonate.

[0050] The aromatic oil was purchased from Shandong Xinglong New Materials Co., Ltd.

[0051] Among them, triethylene glycol diisooctanoate was purchased from Hubei Xinghengye Technology Co., Ltd.

[0052] 2-Ethylhexyl diphenyl phosphate was purchased from Shanghai Yuanye Biotechnology Co., Ltd.

[0053] Dioctyl terephthalate was purchased from Zhongrun (Shandong) New Materials Co., Ltd.

[0054] The epoxidized soybean oil was purchased from Shandong Deyitai New Materials Co., Ltd.

[0055] Dipropylene glycol methyl ether acetate was purchased from Shandong Jinyida Chemical Co., Ltd.

[0056] The polymethylene polyphenyl polyisocyanate was purchased from Jinan Quanhui Chemical Co., Ltd., model NA-100.

[0057] Among them, oleic acid-based hydroxyethyl imidazoline was purchased from Guangzhou Jinglong Technology Co., Ltd.

[0058] Erucamide was purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd.

[0059] Among them, barium petroleum sulfonate was purchased from Jinan Shanzheng Trading Co., Ltd., model: T701.

[0060] The preparation method of the regenerant includes the following steps:

[0061] Step 1: Add aromatic oil to the reactor and heat it to 85°C while stirring.

[0062] Step 2: While stirring, add triethylene glycol diisooctanoate, 2-ethylhexyl diphenyl phosphate, dioctyl terephthalate, epoxidized soybean oil, dipropylene glycol methyl ether acetate, polymethylene polyphenyl polyisocyanate, and oleic acid-based hydroxyethyl imidazoline in sequence, and continue stirring until evenly mixed.

[0063] Step 3: While stirring, slowly add erucamide and barium petroleum sulfonate, and homogenize until evenly mixed.

[0064] Step 4: Turn on the vacuum pump and dehydrate at a vacuum of -0.08MPa and 90℃ for 40 minutes to obtain the regenerant.

[0065] Preparation Example 3

[0066] A regenerator comprises 70g aromatic oil, 10g triethylene glycol diisooctanoate, 5g 2-ethylhexyl diphenyl phosphate, 8g dioctyl terephthalate, 5g epoxidized soybean oil, 3g dipropylene glycol methyl ether acetate, 5g polymethylene polyphenyl polyisocyanate, 1g oleic acid-based hydroxyethyl imidazoline, 0.5g erucamide, and 2g barium petroleum sulfonate.

[0067] The preparation method of the regenerant includes the following steps:

[0068] Step 1: Add aromatic oil to the reaction vessel and heat it to 80°C while stirring.

[0069] Step 2: While stirring, add triethylene glycol diisooctanoate, 2-ethylhexyl diphenyl phosphate, dioctyl terephthalate, epoxidized soybean oil, dipropylene glycol methyl ether acetate, polymethylene polyphenyl polyisocyanate, and oleic acid-based hydroxyethyl imidazoline in sequence, and continue stirring until evenly mixed.

[0070] Step 3: While stirring, slowly add erucamide and barium petroleum sulfonate, and homogenize until evenly mixed.

[0071] Step 4: Turn on the vacuum pump and dehydrate at a vacuum of -0.095MPa and 80℃ for 30 minutes to obtain the regenerant.

[0072] Preparation Example 4

[0073] A regenerator comprises 60g aromatic oil, 15g triethylene glycol diisooctanoate, 6g 2-ethylhexyl diphenyl phosphate, 8g dioctyl terephthalate, 5g epoxidized soybean oil, 4g dipropylene glycol methyl ether acetate, 4g polymethylene polyphenyl polyisocyanate, 2g oleic acid-based hydroxyethyl imidazoline, 1g erucamide, and 1g barium petroleum sulfonate.

[0074] The preparation method of the regenerant includes the following steps:

[0075] Step 1: Add aromatic oil to the reactor and heat it to 82°C while stirring.

[0076] Step 2: While stirring, add triethylene glycol diisooctanoate, 2-ethylhexyl diphenyl phosphate, dioctyl terephthalate, epoxidized soybean oil, dipropylene glycol methyl ether acetate, polymethylene polyphenyl polyisocyanate, and oleic acid-based hydroxyethyl imidazoline in sequence, and continue stirring until evenly mixed.

[0077] Step 3: While stirring, slowly add erucamide and barium petroleum sulfonate, and homogenize until evenly mixed.

[0078] Step 4: Turn on the vacuum pump and dehydrate at a vacuum of -0.09MPa and 805℃ for 35 minutes to obtain the regenerant.

[0079] Preparation Example 5

[0080] A regenerant, which differs from Preparation Example 2 in that polymethylene polyphenyl polyisocyanate is replaced in equal amounts with toluene diisocyanate.

[0081] Toluene diisocyanate was purchased from Shandong Rongsheng New Materials Co., Ltd.

[0082] Preparation Example 6

[0083] A regenerant, which differs from Preparation Example 2 in that an equal amount of oleic acid-based hydroxyethyl imidazoline is replaced with hexadecyltrimethylammonium chloride.

[0084] Hexadecyltrimethylammonium chloride was purchased from Shandong Yueyang New Materials Co., Ltd.

[0085] Preparation Example 7

[0086] A regenerant, which differs from Preparation Example 2 in that erucamide is replaced in equal amounts with stearamide.

[0087] The stearamide was purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd.

[0088] Preparation Example 8

[0089] A regenerant, which differs from Preparation Example 2 in that barium petroleum sulfonate is replaced in equal amounts with sodium petroleum sulfonate.

[0090] Sodium petroleum sulfonate was purchased from Shandong Yuxing Fine Chemical Co., Ltd.

[0091] Preparation Example 9

[0092] A regenerant, unlike Preparation Example 2, is free of polymethylene polyphenyl polyisocyanate, oleyl hydroxyethyl imidazoline, erucamide, and barium petroleum sulfonate.

[0093] Preparation Example 10

[0094] A method for preparing coconut shell fiber includes the following steps:

[0095] Step s1: Take a fresh coconut shell, wash it clean, and then break it into small pieces;

[0096] Step s2: Remove the fragments and soak them in a 10wt% sodium hydroxide aqueous solution, then boil them at a pressure of 0.3MPa and a temperature of 80℃ for 4 hours.

[0097] Step s3: Remove the fragments, clean them, and dry them to a constant weight.

[0098] Step s4: Remove the fragments, crush them, and screen out fibers of 0.1~0.5mm.

[0099] Step s5: Spray the modified solution evenly onto the fiber surface until the fiber is completely wetted.

[0100] Step s6: After drying again, the desired coconut shell fiber is obtained.

[0101] The modified solution is composed of polyaluminum sulfate, diallyl dimethyl ammonium chloride, sodium cocoyl glutamate and water in a mass ratio of 3:2:1:100.

[0102] Polyaluminum sulfate was purchased from Henan Maoxing Environmental Protection Technology Co., Ltd.

[0103] Diallyl dimethyl ammonium chloride was purchased from Wuhan Smike Biotechnology Co., Ltd.

[0104] Sodium cocoyl glutamate was purchased from Wuhan Shuer Biotechnology Co., Ltd.

[0105] Preparation Example 11

[0106] A method for preparing coconut shell fiber includes the following steps:

[0107] Step s1: Take a fresh coconut shell, wash it clean, and then break it into small pieces;

[0108] Step s2: Remove the fragments and soak them in a 10wt% sodium hydroxide aqueous solution, then boil them at a pressure of 0.1MPa and a temperature of 100℃ for 3 hours.

[0109] Step s3: Remove the fragments, clean them, and dry them to a constant weight.

[0110] Step s4: Remove the fragments, crush them, and screen out fibers of 0.1~0.5mm.

[0111] Step s5: Spray the modified solution evenly onto the fiber surface until the fiber is completely wetted.

[0112] Step s6: After drying again, the desired coconut shell fiber is obtained.

[0113] The modified solution is composed of polyaluminum sulfate, diallyl dimethyl ammonium chloride, sodium cocoyl glutamate, and water in a mass ratio of 5:0.5:3:100.

[0114] Preparation Example 12

[0115] A method for preparing coconut shell fiber includes the following steps:

[0116] Step s1: Take a fresh coconut shell, wash it clean, and then break it into small pieces;

[0117] Step s2: Remove the fragments and soak them in a 10wt% sodium hydroxide aqueous solution, then boil them at a pressure of 0.2MPa and a temperature of 95℃ for 3.5h.

[0118] Step s3: Remove the fragments, clean them, and dry them to a constant weight.

[0119] Step s4: Remove the fragments, crush them, and screen out fibers of 0.1~0.5mm.

[0120] Step s5: Spray the modified solution evenly onto the fiber surface until the fiber is completely wetted.

[0121] Step s6: After drying again, the desired coconut shell fiber is obtained.

[0122] The modified solution is composed of polyaluminum sulfate, diallyl dimethyl ammonium chloride, sodium cocoyl glutamate and water in a mass ratio of 4:1:2:100.

[0123] Preparation Example 13

[0124] A method for preparing coconut shell fiber, which differs from preparation example 10, is that polyaluminum sulfate is replaced in equal amounts with potassium aluminum sulfate.

[0125] Potassium aluminum sulfate was purchased from Shandong Wanhua Environmental Protection New Materials Co., Ltd.

[0126] Preparation Example 14

[0127] A method for preparing coconut shell fiber, which differs from preparation example 10, is that diallyl dimethyl ammonium chloride is replaced in equal amounts with dimethyl diallyl ammonium chloride.

[0128] Dimethyl diallyl ammonium chloride was purchased from Jiangsu Bost Chemical Technology Co., Ltd.

[0129] Preparation Example 15

[0130] A method for preparing coconut shell fiber, which differs from Preparation Example 10 in that an equal amount of sodium cocoyl glutamate is replaced with cocamidopropyl betaine.

[0131] Among them, cocamidopropyl betaine was purchased from Errek (Shandong) Chemical Group Co., Ltd.

[0132] Preparation Example 16

[0133] A method for preparing coconut shell fiber includes the following steps:

[0134] Step s1: Take a fresh coconut shell, wash it clean, and then break it into small pieces;

[0135] Step s2: Remove the fragments and soak them in a 10wt% sodium hydroxide aqueous solution, then boil them at a pressure of 0.2MPa and a temperature of 95℃ for 3.5h.

[0136] Step s3: Remove the fragments, clean them, and dry them to a constant weight to obtain the desired coconut shell fiber.

[0137] Example 1

[0138] A durable recycled asphalt mixture comprises: 60 kg of waste asphalt mixture recycled material, 4 kg of new asphalt, 15 kg of new aggregate, 2 kg of fiber, 3 kg of recycling agent, and 2 kg of filler.

[0139] The recycled waste asphalt mixture comes from Preparation Example 1.

[0140] Among them, the new asphalt is Panjin 90# base asphalt.

[0141] The fiber was derived from Preparation Example 10.

[0142] The regenerant was derived from Preparation Example 2.

[0143] The recycled asphalt mixture is made by mixing RAP particles with a particle size of 0~11mm, 11~17mm and 17~22mm in a mass ratio of 1:1:1.5.

[0144] The new aggregate is made by mixing limestone with a particle size of 0.45~3mm, limestone with a particle size of 5~10mm and limestone with a particle size of 10~15mm in a mass ratio of 5:6:4.5.

[0145] The filler is a mixture of limestone powder and silica fume in a 3:1 mass ratio.

[0146] The preparation method of recycled asphalt mixture with good durability includes the following steps:

[0147] Step 1: Add new asphalt, new aggregates, and fillers to mixing pot 1, heat to 150℃, mix thoroughly, and keep warm for later use.

[0148] Step 2: Add the recycled waste asphalt mixture to mixing pot 2, preheat to 110°C, and spray the recycling agent while mixing until fully mixed.

[0149] Step 3: At 110℃, add the material obtained in Step 1 to the material obtained in Step 2, and add the fiber while mixing until fully mixed to obtain a recycled asphalt mixture with good durability.

[0150] Example 2

[0151] A durable recycled asphalt mixture comprises: 70 kg of waste asphalt mixture, 5 kg of new asphalt, 16 kg of new aggregate, 3 kg of fiber, 5 kg of recycling agent, and 4 kg of filler.

[0152] The recycled waste asphalt mixture comes from Preparation Example 1.

[0153] Among them, the new asphalt is Panjin 90# base asphalt.

[0154] The fiber was derived from Preparation Example 11.

[0155] The regenerant was derived from Preparation Example 3.

[0156] The recycled asphalt mixture is made by mixing RAP particles with a particle size of 0-11mm, 11-17mm and 17-22mm in a mass ratio of 1.5:1.5:1.8.

[0157] The new aggregate is made by mixing limestone with a particle size of 0.45-3mm, limestone with a particle size of 5-10mm and limestone with a particle size of 10-15mm in a mass ratio of 5.5:7:5.

[0158] The filler is a mixture of limestone powder and silica fume in a mass ratio of 5:2.

[0159] The preparation method of recycled asphalt mixture with good durability includes the following steps:

[0160] Step 1: Add new asphalt, new aggregates, and fillers to mixing pot 1, heat to 160℃, mix thoroughly, and keep warm for later use.

[0161] Step 2: Add the recycled waste asphalt mixture to mixing pot 2, preheat to 105°C, and spray the recycling agent while mixing until fully mixed.

[0162] Step 3: At 105℃, add the material obtained in Step 1 to the material obtained in Step 2, and add the fiber while mixing until fully mixed to obtain a recycled asphalt mixture with good durability.

[0163] Example 3

[0164] A durable recycled asphalt mixture comprises: 80 kg of waste asphalt mixture recycled material, 7 kg of new asphalt, 18 kg of new aggregate, 5 kg of fiber, 7 kg of recycling agent, and 5 kg of filler.

[0165] The recycled waste asphalt mixture comes from Preparation Example 1.

[0166] Among them, the new asphalt is Panjin 90# base asphalt.

[0167] The fiber in this example comes from Preparation Example 12.

[0168] The regenerant was derived from Preparation Example 4.

[0169] The recycled asphalt mixture is made by mixing RAP particles with a particle size of 0~11mm, 11~17mm and 17~22mm in a mass ratio of 2:2:2.5.

[0170] The new aggregate is made by mixing limestone with a particle size of 0.45-3mm, limestone with a particle size of 5-10mm and limestone with a particle size of 10-15mm in a mass ratio of 6:8:4.

[0171] The filler is a mixture of limestone powder and silica fume in a mass ratio of 3.5:1.7.

[0172] The preparation method of recycled asphalt mixture with good durability includes the following steps:

[0173] Step 1: Add new asphalt, new aggregates, and fillers to mixing pot 1, heat to 155℃, mix thoroughly, and keep warm for later use.

[0174] Step 2: Add the recycled waste asphalt mixture to mixing pot 2, preheat to 109°C, and spray the recycling agent while mixing until fully mixed.

[0175] Step 3: At 108℃, add the material obtained in Step 1 to the material obtained in Step 2, and add the fiber while mixing until fully mixed to obtain a recycled asphalt mixture with good durability.

[0176] Example 4

[0177] A durable recycled asphalt mixture, unlike Example 1, uses fibers derived from Preparation Example 13.

[0178] Example 5

[0179] A durable recycled asphalt mixture, unlike Example 1, uses fibers derived from Preparation Example 14.

[0180] Example 6

[0181] A durable recycled asphalt mixture, unlike Example 1, uses fibers derived from Preparation Example 15.

[0182] Example 7

[0183] A durable recycled asphalt mixture, unlike Example 1, uses fibers derived from Preparation Example 16.

[0184] Comparative Example 1

[0185] A recycled asphalt mixture, which differs from Example 1 in that the recycling agent is derived from Preparation Example 5.

[0186] Comparative Example 2

[0187] A recycled asphalt mixture, which differs from Example 1 in that the recycling agent is derived from Preparation Example 6.

[0188] Comparative Example 3

[0189] A recycled asphalt mixture, which differs from Example 1 in that the recycling agent is derived from Preparation Example 7.

[0190] Comparative Example 4

[0191] A recycled asphalt mixture, which differs from Example 1 in that the recycling agent is derived from Preparation Example 8.

[0192] Comparative Example 5

[0193] A recycled asphalt mixture, which differs from Example 1 in that the recycling agent is derived from Preparation Example 9.

[0194] Road performance testing

[0195] 1. Marshall stability: The Marshall stability test of asphalt mixtures was conducted in accordance with T0709-2000.

[0196] 2. Residual stability after immersion in water: The stability was determined in accordance with T0709-2000 "Marshall stability test of asphalt mixture".

[0197] 3. Dynamic stability of rutting test: The test shall be conducted in accordance with JTG E20-2011 "Test Procedures for Asphalt and Mixtures in Highway Engineering".

[0198] 4. Freeze-thaw splitting residual strength ratio: The method in T0729-2000 of JTJ052-2000 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" was used for determination.

[0199] 5. Low-temperature bending test: The bending test of asphalt mixture is conducted in accordance with the method of JTG E20-2011 "Test Procedures for Asphalt and Mixtures in Highway Engineering".

[0200] The road performance tests were conducted on the recycled asphalt mixtures of each embodiment and comparative example of this application, and the test results are shown in Table 1.

[0201] Table 1:

[0202] <![CDATA[ 样品 项目 ]]> Marshall stability Water immersion residual stability Dynamic stability (70℃) Residual strength ratio Destructive strain unit kN % times / mm % με Example 1 16.5 92.7 4512 90.4 3086.3 Example 2 16.3 91.6 4468 89.2 3006.8 Example 3 16.7 92.2 4490 91.3 3114.5 Example 4 16.1 90.4 4306 88.4 2637.6 Example 5 15.8 88.5 4327 87.2 2596.9 Example 6 15.6 89.3 4293 87.9 2553.1 Example 7 14.9 87.2 4204 86.3 2259.4 Comparative Example 1 10.2 80.1 3980 78.4 2083.8 Comparative Example 2 9.8 78.6 4075 76.3 2049.9 Comparative Example 3 9.5 76.4 4002 75.1 2004.5 Comparative Example 4 9.2 76.8 4198 73.9 1986.5 Comparative Example 5 8.9 73.1 5074 68.2 1731.4

[0203] Based on the analysis of Examples 1-7 and Comparative Examples 1-5, it can be seen that the recycled asphalt mixtures prepared in Examples 1-7 all performed well in various road performance test indicators. This indicates that the recycled asphalt mixtures in Examples 1-7 have good durability and can maintain stable performance under various environmental conditions, meeting the strict requirements of road engineering for material durability.

[0204] Compared with Example 1, Comparative Examples 1-5 showed varying degrees of change in various road performance indicators due to the alteration of the recycler composition. This demonstrates that the addition of the four components—polymethylene polyphenyl polyisocyanate, oleic acid-based hydroxyethyl imidazoline, erucamide, and barium petroleum sulfonate—plays a crucial role in improving the performance of the recycler. Only through the synergistic effect of these four components can the durability of recycled asphalt mixtures be significantly improved.

[0205] Compared with Example 1, Examples 4-7 showed varying degrees of change in various road performance indicators due to the addition of coconut shell fibers prepared by different methods. This demonstrates that the preparation method of coconut shell fibers, especially the composition of the modification solution used for coconut shell fibers, has a significant impact on the performance of recycled asphalt mixtures. Only coconut shell fibers treated with a modification solution composed of polyaluminum sulfate, diallyl dimethyl ammonium chloride, sodium cocoyl glutamate, and water can exhibit good road performance. This indicates that the specific modification solution of this application can improve the compatibility and reinforcing effect of coconut shell fibers with asphalt mixtures, and promote the formation of a stable structure between coconut shell fibers and asphalt, thereby effectively improving the durability of recycled asphalt mixtures.

[0206] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A durable recycled asphalt mixture, characterized in that, The raw materials include the following parts by weight: 60-80 parts recycled waste asphalt mixture, 4-7 parts new asphalt, 15-18 parts new aggregate, 2-5 parts fiber, 3-7 parts recycling agent, and 2-5 parts filler; Based on the mass fractions of the regenerant, the regenerant comprises 50-70 parts aromatic oil, 10-20 parts triethylene glycol diisooctanoate, 5-8 parts 2-ethylhexyl diphenyl phosphate, 5-8 parts dioctyl terephthalate, 3-5 parts epoxidized soybean oil, 3-5 parts dipropylene glycol methyl ether acetate, 3-5 parts polymethylene polyphenyl polyisocyanate, 1-3 parts oleic acid-based hydroxyethyl imidazoline, 0.5-2 parts erucamide, and 0.5-2 parts barium petroleum sulfonate; The method for preparing the regenerant includes the following steps: Step 1: Add aromatic oil to the reaction vessel and heat it to 80~85℃ while stirring; Step 2: While stirring, add triethylene glycol diisooctanoate, 2-ethylhexyl diphenyl phosphate, dioctyl terephthalate, epoxidized soybean oil, dipropylene glycol methyl ether acetate, polymethylene polyphenyl polyisocyanate, and oleic acid hydroxyethyl imidazoline in sequence, and continue stirring until the mixture is homogeneous. Step 3: While stirring, slowly add erucamide and barium petroleum sulfonate, and homogenize until evenly mixed; Step 4: Turn on the vacuum pump and dehydrate at a vacuum of -0.08 to -0.095 MPa and a temperature of 80 to 90°C for 30 to 40 minutes to obtain the regenerant.

2. The durable recycled asphalt mixture according to claim 1, characterized in that, Based on the mass fractions of the regenerant, the regenerant comprises 60 parts aromatic oil, 15 parts triethylene glycol diisooctanoate, 6 parts 2-ethylhexyl diphenyl phosphate, 8 parts dioctyl terephthalate, 5 parts epoxidized soybean oil, 4 parts dipropylene glycol methyl ether acetate, 4 parts polymethylene polyphenyl polyisocyanate, 2 parts oleic acid-based hydroxyethyl imidazoline, 1 part erucamide, and 1 part barium petroleum sulfonate.

3. The durable recycled asphalt mixture according to claim 1, characterized in that, The fiber is coconut shell fiber.

4. The durable recycled asphalt mixture according to claim 3, characterized in that, The method for preparing the coconut shell fiber includes the following steps: Step s1: Take a fresh coconut shell, wash it clean, and then break it into small pieces; Step s2: Remove the fragments and soak them in a 10wt% sodium hydroxide aqueous solution, then cook them at a pressure of 0.1~0.3MPa and a temperature of 80~100℃ for 3~4 hours; Step s3: Remove the fragments, clean them, and dry them to a constant weight; Step s4: Remove the fragments, crush them, and sieve out fibers of 0.1~0.5mm; Step s5: Spray the modified solution evenly on the fiber surface until the fiber is completely wetted, wherein the modified solution is a mixture of polyaluminum sulfate, diallyl dimethyl ammonium chloride, sodium cocoyl glutamate and water in a mass ratio of (3~5):(0.5~2):(1~3):100; Step s6: After drying again, the desired coconut shell fiber is obtained.

5. A durable recycled asphalt mixture according to claim 4, characterized in that, The modified solution is prepared by mixing polyaluminum sulfate, diallyl dimethyl ammonium chloride, sodium cocoyl glutamate and water in a mass ratio of 4:1:2:

100.

6. The durable recycled asphalt mixture according to claim 1, characterized in that, The filler is a mixture of limestone powder and silica fume in a mass ratio of (3~5):(1~2).

7. The durable recycled asphalt mixture according to claim 1, characterized in that, The new aggregate is a mixture of limestone with a particle size of 0.45-3 mm, limestone with a particle size of 5-10 mm, and limestone with a particle size of 10-15 mm in a mass ratio of (5-6):(6-8):(4-5).

8. A durable recycled asphalt mixture according to claim 1, characterized in that, The recycled waste asphalt mixture is made by mixing RAP particles with a particle size of 0~11mm, 11~17mm and 17~22mm in a mass ratio of (1~2):(1~2):(1.5~2.5).

9. A method for preparing a durable recycled asphalt mixture as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Step 1: Add new asphalt, new aggregates, and fillers to mixing pot 1, heat to 150~160℃, mix thoroughly, and keep warm for later use; Step 2: Add the recycled waste asphalt mixture to mixing pot 2, preheat to 105~110℃, and spray the recycling agent while mixing until fully mixed; Step 3: At 105~110℃, add the material obtained in Step 1 to the material obtained in Step 2, and add the fiber while mixing until fully mixed to obtain a recycled asphalt mixture with good durability.