Special regenerant for asphalt milling material oilstone fine separation fine material as well as preparation method and application of regenerant

Abstract

The invention belongs to the technical field of road engineering materials, and particularly relates to a special regenerant for fine materials for fine separation of asphalt milling materials and oilstones as well as a preparation method and application of the regenerant. The regenerant is formed by compounding vegetable pitch, petroleum-based regenerated base oil, resin, an interface activating and penetrating agent, an anti-aging agent and a compatible stabilizer according to a specific proportion. According to the invention, aiming at a special difficult-to-regenerate fine material which is an oilstone fine separation fine material, the problems of difficult permeation, poor compatibility and poor dispersion of a conventional regenerant are solved through a multi-component synergistic effect. The regenerant can deeply permeate and effectively regenerate highly aged asphalt in fine materials, the rheological property and surface characteristics of the highly aged asphalt are remarkably improved, the highly aged asphalt is converted into high-performance asphalt mixture functional filler, and high-value cyclic utilization of all components of RAP is achieved. The regenerant is simple in preparation process, convenient to use and easy to popularize and apply in an existing asphalt mixing system.

Description

Technical Field

[0001] This invention belongs to the field of road engineering materials technology, specifically relating to a special regenerator for fine separation of asphalt milling aggregate and its preparation method and application. Background Technology

[0002] With the full arrival of the era of highway maintenance in my country, a huge amount of asphalt pavement excavated material (RAP) is generated every year. To achieve high-value recycling of RAP, fine separation technology of asphalt and aggregate has received widespread attention. This technology can efficiently separate aged asphalt from aggregate in RAP, obtaining clean aggregate and fine powder rich in aged asphalt.

[0003] Oil-rich asphalt fine aggregates pose significant challenges to the design of thermally recycled asphalt mixtures: 1) The extremely high asphalt content and severely aged asphalt properties of oil-rich asphalt fine aggregates can lead to inaccurate estimation of asphalt content in recycled mixtures, easily resulting in bleeding, rutting, and other defects. 2) The high viscosity of aged asphalt with thick oil films makes it difficult for conventional recycling agents to effectively penetrate and fuse, resulting in poor recycling effects. 3) To avoid the above problems, projects are often forced to reduce the amount of this fine aggregate or even discard it, which not only wastes resources and pollutes the environment but also limits the increase of the overall RAP (Regenerative Apparent Polymer) content.

[0004] Currently, conventional asphalt recycling agents are mainly designed for ordinary RAP or medium-to-coarse particle RAP, with their components focusing on replenishing light oils and adjusting colloidal structure. However, for finely separated particles with more complex compositions, deeper aging, and larger specific surface areas, conventional recycling agents have the following shortcomings: 1) Poor permeability, making it difficult to penetrate into the interior of fine particle agglomerates; 2) Insufficient compatibility, failing to effectively dissolve and reorganize deeply aged asphaltene; 3) Insufficient adjustment of the surface energy of fine particles, failing to improve their dispersibility in the mixture; 4) Limited performance recovery of recycled fine particles, making them unsuitable for effective use as functional fillers.

[0005] Therefore, there is an urgent need to develop a targeted regenerant to activate the potential value of finely separated materials and achieve 100% high-value recycling of all RAP components. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies. This invention provides a special regenerator for fine separation of asphalt milling aggregate and asphalt stone, its preparation method, and its application. The specific technical solution of this invention is as follows:

[0007] One of the technical solutions of this invention is to provide a special regenerator for fine separation of asphalt milling material and asphalt aggregate, which is composed of the following components by mass:

[0008] Vegetable bitumen or tall oil bitumen: 20-45 parts;

[0009] Petroleum-based recycled base oil: 15-35 parts;

[0010] Terpene resin or C5 / C9 petroleum resin: 10-25 parts;

[0011] Interface activator and penetrant: 3-10 parts;

[0012] Anti-aging agent: 1-5 parts;

[0013] Compatibility stabilizer: 2-8 parts.

[0014] As a further option for the regenerator of the present invention, the content of the plant bitumen or tall oil bitumen is 25-40 parts.

[0015] As a further option for the regenerator of the present invention, the plant bitumen is selected from at least one of palm oil bitumen, soybean oil bitumen, or rosin bitumen.

[0016] As a further option for the regenerator of the present invention, the petroleum-based regenerated base oil is a naphthenic base oil or an aromatic base oil, and the kinematic viscosity of the petroleum-based regenerated base oil at 60°C is 800-2500 mm² / s.

[0017] As a further option for the regenerator of the present invention, the petroleum-based regenerated base oil has a kinematic viscosity of 1000-2000 mm² / s at 60°C.

[0018] As a further option for the regenerator of the present invention, the content of the terpene resin or C5 / C9 petroleum resin is 12-22 parts.

[0019] As a further option for the regenerator of the present invention, the interface activator and penetrant is selected from at least one of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether or organosilicon surfactant, and the content of the interface activator and penetrant is 4-8 parts.

[0020] As a further option for the regenerator of the present invention, the anti-aging agent includes hindered phenolic primary antioxidant and phosphite secondary antioxidant, wherein the mass ratio of the primary antioxidant to the secondary antioxidant is 1:1 to 1:3.

[0021] As a further option for the regenerator of the present invention, the compatibility stabilizer is selected from at least one of maleic anhydride graft polymer, polyfunctional amine compound or organobentonite, and the content of the compatibility stabilizer is 3-6 parts.

[0022] The second technical solution of the present invention is to provide a method for preparing a regenerant, comprising the following steps:

[0023] a) Mix vegetable bitumen or tall oil bitumen with petroleum-based recycled base oil at 80-110℃ to obtain mixture A;

[0024] b) Heat mixture A to 120-140℃, add terpene resin or C5 / C9 petroleum resin, and stir until completely melted to obtain mixture B;

[0025] c) Cool mixture B to 70-90℃, add interfacial activator and penetrant, anti-aging agent and compatibility stabilizer, and perform high-speed shear stirring to obtain homogenized product;

[0026] d) Cool the homogenized product to room temperature and filter it to obtain the regenerant.

[0027] As a further option of the regenerant preparation method of the present invention, the stirring speed in step a) is 200-500 rpm; in step c), after adding all the additives, the speed is increased to 300-600 rpm to perform the high-speed shear stirring.

[0028] The third technical solution of the present invention is to provide the application of a regenerator, which is used to regenerate fine material rich in aged asphalt obtained after fine separation of oilstone and stone.

[0029] As a further option for the application of the regenerant of the present invention, the following steps are included:

[0030] S1: Preheat the fine material obtained from the fine separation of oilstone to 100-120°C, and preheat the regenerant to 60-80°C;

[0031] S2: Weigh 5%-10% of the preheated regenerant by weight of the fine material, and mechanically mix it with the preheated fine material at 100-120°C for at least 90 seconds.

[0032] S3: Use the uniformly mixed recycled fine aggregates for the preparation of asphalt mixtures.

[0033] As a further option for the application of the regenerator of the present invention, in step S1, the regenerator is preheated to a state where it is easy to flow.

[0034] The beneficial effects of the technical solutions provided in this application include at least the following:

[0035] 1) The component design is specifically designed to address the characteristics of high asphalt content, high viscosity, and strong agglomeration of fine particles from oilstone fine separation, solving the three core problems of penetration, compatibility, and dispersion.

[0036] 2) It can not only effectively restore the physical properties of aged asphalt, but also significantly improve its rheological properties, transforming fine particles from harmful substances into functional fillers.

[0037] 3) The recycled fine aggregate can be directly used in existing asphalt mixing plants without changing the production process, making it easy to promote.

[0038] 4) It has achieved 100% resource utilization of the most difficult-to-utilize component in RAP, reduced mining and solid waste emissions, lowered road construction costs, and achieved significant economic and social benefits. Attached Figure Description

[0039] Figure 1 This is a flowchart of the regenerant preparation process. Detailed Implementation

[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0041] This invention provides a composite regenerator for fine aggregates obtained from the fine separation of asphalt and aggregate in asphalt milling, its preparation method, and its application. The composite regenerator is prepared through the synergistic compounding of specific components and optimized temperature and shear processes. It is specifically designed for the deep regeneration of fine aggregates rich in severely aged asphalt obtained after fine separation of asphalt and aggregate. It can efficiently penetrate and effectively restore the physical and rheological properties of aged asphalt, transforming it into a high-performance functional filler for asphalt mixtures, thereby achieving high-value recycling of all components of reclaimed asphalt pavement (RAP).

[0042] First, the composition of the composite regenerator will be described in detail.

[0043] The composite regenerant comprises the following key components by weight:

[0044] Vegetable bitumen or tall oil bitumen: 20-45 parts.

[0045] Petroleum-based recycled base oil: 15-35 parts.

[0046] Terpene resin or C5 / C9 petroleum resin: 10-25 parts.

[0047] Interface activator and penetrant: 3-10 parts.

[0048] Anti-aging agent: 1-5 parts.

[0049] Compatibility stabilizer: 2-8 parts.

[0050] In this invention, plant-based bitumen or tall oil bitumen serves as the core of the soft recycling process, providing good compatibility with deeply aged petroleum bitumen. Utilizing its rich content of natural esters, acids, and other active functional groups, it partially disrupts the cross-linking network between aged asphalt molecules, restoring the system's flexibility. The plant-based bitumen is preferably selected from at least one of palm oil bitumen, soybean oil bitumen, or rosin bitumen. Tall oil bitumen, as a byproduct of pine pulping, also contains abundant resin acids and fatty acids, exhibiting similar regeneration and plasticizing functions. The content of the plant-based bitumen or tall oil bitumen component is 20-45 parts. If the content is too low (below 20 parts), the softening and structural reorganization capabilities of the aged bitumen will be insufficient; if the content is too high (above 45 parts), it may lead to excessive softening of the recycling system, loss of high-temperature performance, and increased costs. The preferred range is 25-40 parts.

[0051] In this invention, petroleum-based recycled base oil serves as a supplementary oil component and viscosity modifier. Its main function is to dilute highly concentrated and viscous aged asphalt, effectively reducing its viscosity, restoring necessary fluidity, and facilitating construction mixing and subsequent molding. The petroleum-based recycled base oil is preferably a naphthenic or aromatic base oil. The kinematic viscosity of the petroleum-based recycled base oil at 60°C is in the range of 800-2500 mm² / s. While oil components with a kinematic viscosity below 800 mm² / s penetrate quickly, they may cause excessive softening of the recycled asphalt, resulting in insufficient high-temperature performance and easy volatility. Conversely, oil components with a kinematic viscosity above 2500 mm² / s have poor fluidity, making it difficult to effectively penetrate into the fine particles, thus limiting the recycling effect. A viscosity of 1000-2000 mm² / s is preferred. The petroleum-based recycled base oil component content is 15-35 parts, working synergistically with plant-based asphalt to jointly constitute the soft matrix of the recycling system.

[0052] In this invention, terpene resin or C5 / C9 petroleum resin is used as a thickening and toughening component to compensate for the possible loss of viscosity and cohesive strength due to the addition of plant asphalt and light oils. Terpene resin is a natural product derivative with excellent compatibility; C5 or C9 petroleum resin is a petroleum fraction polymerization product with good compatibility with petroleum asphalt, providing additional adhesion and cohesive strength in the recycling system, significantly improving the high-temperature deformation resistance and adhesion to aggregates of the recycled asphalt binder. Its content is 10-25 parts. If the content is less than 10 parts, the thickening and reinforcing effect is not obvious; if the content is more than 25 parts, the recycling agent itself will be too viscous, affecting its spraying, penetration, and mixing uniformity. The preferred range is 12-22 parts.

[0053] In this invention, the interface activator and penetrant are key functional additives for solving the problem of difficult penetration of finely separated materials. Finely separated materials have a large specific surface area, and the aged asphalt film is dense. Conventional recycling agents have high surface tension, making wetting and penetration difficult. The interface activator and penetrant can significantly reduce the surface tension of the recycling agent, improving its wetting, spreading, and penetration capabilities. Preferably, it is at least one of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, or organosilicon surfactant. The amount of interface activator and penetrant used is 3-10 parts. Less than 3 parts will have a limited penetration-promoting effect; more than 10 parts may introduce too many hydrophilic groups, affecting the water resistance of the recycled asphalt and potentially causing foaming. The preferred range is 4-8 parts.

[0054] In this invention, the anti-aging agent preferably employs a composite antioxidant system, composed of a primary antioxidant and a secondary antioxidant. The primary antioxidant is a hindered phenol, and the secondary antioxidant is a phosphite. Hindered phenols can capture free radicals and interrupt the oxidation chain reaction; phosphites can decompose hydroperoxides, preventing them from further initiating oxidation. The combination of the two has a synergistic effect. The preferred mass ratio of the primary antioxidant to the secondary antioxidant is 1:1 to 1:3. The total dosage is 1-5 parts, preferably 2-4 parts. Too low a dosage results in insufficient anti-aging effect; too high a dosage increases cost.

[0055] In this invention, a compatibility stabilizer is used to ensure the long-term homogeneity and stability of a complex multiphase system composed of polar and non-polar / weakly polar components, preventing stratification or precipitation during storage. Simultaneously, the compatibility stabilizer also promotes compatibility between the components of the regenerator and the aged asphalt, assisting in the reconstruction of the colloidal structure. The compatibility stabilizer is preferably at least one of maleic anhydride graft polymers, polyfunctional amine compounds, or organobentonite. Maleic anhydride graft polymers act as a bridge by interacting with the polar components in the asphalt through their anhydride groups; organobentonite, after shear dispersion, can form a network structure in the oil phase, preventing sedimentation. The amount of compatibility stabilizer used is 2-8 parts, preferably 3-6 parts.

[0056] The preparation method provided by this invention ensures that all components are fully dissolved, dispersed, and homogenized. For example... Figure 1 As shown, the specific steps include:

[0057] Step a): At 80-110℃, add the metered vegetable asphalt or tall oil asphalt and petroleum-based recycled base oil to a reactor equipped with a stirring and heating device. Control the stirring speed at 200-500 rpm and continue stirring for 20-40 minutes to obtain mixture A.

[0058] Step b): Heat the base mixture A to 120-140℃, keep stirring, slowly add the metered terpene resin or C5 / C9 petroleum resin, and continue stirring for 30-50 minutes until the resin is completely melted and the system becomes homogeneous, transparent or translucent, to obtain mixture B.

[0059] Step c): Cool mixture B to 70-90℃. After the temperature stabilizes, add the metered interface activator and penetrant, anti-aging agent and compatibility stabilizer in sequence. After adding all the additives, significantly increase the stirring speed to 300-600 rpm and perform high-speed shear stirring for 40-60 minutes to obtain a microscopically uniform and stable homogenized product.

[0060] Step d): Stop heating the homogenized product and allow it to cool naturally or through a jacket to room temperature. After cooling, filter the product using a filter screen to remove trace mechanical impurities or incompletely dispersed particles that may have been introduced during the preparation process, resulting in a viscous liquid composite regenerant with uniform color and texture, which is then ready for packaging and use.

[0061] After obtaining the composite regenerator, the present invention further provides a specific application method of it in the fine material obtained by fine separation of recycled asphalt milling material and asphalt stone.

[0062] The core of this application method lies in preheating and thorough mixing to ensure full contact and penetration between the regenerator and the fine materials. Specifically, this includes:

[0063] S1: The fine material obtained by fine separation of oilstone is preheated to 100-120°C in an oven. At the same time, the composite regenerator described in this invention is preheated in a water bath or other means at 60-80°C to significantly increase its fluidity and make it easy to spray or pour.

[0064] S2: Weigh out a predetermined mass of preheated fine aggregate, and add the corresponding mass of preheated recycling agent at an external admixture rate of 5%-10% of the fine aggregate mass. Place both together in a small asphalt mixing pot or similar mechanical mixing equipment. While maintaining the material temperature at 100-120℃, perform mechanical forced mixing for at least 90 seconds. Preferably, the mixing time is 90-150 seconds. During this process, the recycling agent is broken into tiny droplets under mechanical force, uniformly coating the surface of each fine aggregate particle. Under the action of the interface activator, it rapidly wets the surface and begins to penetrate into the interior of the aged asphalt film and the gaps in the fine aggregate aggregates.

[0065] S3: The fine aggregate after the above mixing and recycling process is used in existing asphalt mixing plants.

[0066] Through the above application methods, the regenerator of the present invention can achieve deep and efficient regeneration of finely separated materials, thereby transforming the waste problem in traditional technology into a functional resource, which greatly improves the utilization rate of RAP, and even moves towards the utilization of all components.

[0067] To further illustrate the present invention, the composite regenerator of the present invention, its preparation, performance, and application effects are described in detail below with reference to several embodiments and comparative examples. However, these embodiments should not be construed as limiting the scope of protection of the present invention.

[0068] Example 1: Preparation of composite regenerant S1

[0069] Prepare the following materials according to the following mass ratio: 30 parts palm oil asphalt, 25 parts naphthenic base oil, 18 parts terpene resin, 5 parts alkylphenol polyoxyethylene ether (OP-10), 10101 parts antioxidant, 1682 parts antioxidant, and 6 parts maleic anhydride grafted polyolefin. The total mass is 87 parts.

[0070] The preparation steps are as follows:

[0071] (1) Add 30 parts of palm oil asphalt and 25 parts of naphthenic base oil to a 2L reactor equipped with a stirrer and an electric heating mantle. Turn on the stirrer and heat, control the material temperature at 95±2℃, and continue stirring at this temperature for 30 minutes. Observe that the mixture has a uniform color and good fluidity, then stop heating to obtain mixture A.

[0072] (2) Reheat mixture A to 130±2℃. While stirring at 300 rpm, slowly add 18 parts of terpene resin. After the addition is complete, maintain the temperature at 130±2℃ and continue stirring for 40 minutes. During this time, the resin lumps gradually disappear, the viscosity of the mixture increases, and it eventually becomes a uniform dark brown viscous liquid. Stop heating to obtain mixture B.

[0073] (3) Cool the mixture B by circulating water through the jacket to reduce the temperature to 80±2℃. While stirring, add 5 parts OP-10, 1 part antioxidant 1010, 2 parts antioxidant 168, and 6 parts maleic anhydride-grafted polyolefin compatibilizer to the reactor in sequence. After adding all the additives, increase the stirring speed to 500 rpm for high-speed shear stirring. Maintain the temperature at around 80℃ and continue stirring for 50 minutes. During this process, the mixture is further homogenized.

[0074] (4) After stirring, stop heating, remove the product from the reactor, and place it on a stainless steel tray to cool naturally to room temperature. After cooling, filter it using a 200-mesh stainless steel filter to obtain approximately 87 parts by weight of a brownish-red, uniform, and fine viscous liquid, denoted as composite regenerant S1. It is easy to stir at room temperature and has good fluidity at 70°C.

[0075] Example 2: Preparation of composite regenerant S2

[0076] Prepare the following materials according to the following mass ratio: 35 parts tall oil asphalt, 20 parts aromatic base oil, 15 parts C5 petroleum resin, 4 parts fatty alcohol polyoxyethylene ether (AEO-9), 10761.5 parts antioxidant, 1681.5 parts antioxidant, and 3 parts organic bentonite. The total mass is 80 parts.

[0077] The preparation steps are as follows:

[0078] (1) Add 35 parts tall oil pitch and 20 parts aromatic base oil to the reactor, heat to 105°C, and stir at 400 rpm for 25 minutes to obtain mixture A.

[0079] (2) Heat to 135°C, add 15 parts of C5 petroleum resin, keep at 135°C and stir at 400 rpm for 35 minutes until the resin is completely melted, to obtain mixture B.

[0080] (3) Cool down to 85℃, and add 4 parts AEO-9, 1.5 parts antioxidant 1076, 1.5 parts antioxidant 168 and 3 parts organic bentonite powder in sequence. Increase the speed to 550 rpm and shear and stir at high speed for 45 minutes.

[0081] (4) Cool to room temperature and filter through a 180-mesh filter to obtain a dark brown, uniform, viscous liquid, which is denoted as composite regenerator S2.

[0082] Example 3: Preparation of composite regenerant S3

[0083] Prepare the following materials according to the following mass ratio: 40 parts soybean oil asphalt, 15 parts naphthenic base oil, 22 parts terpene resin, 6 parts OP-10, 2 parts and 2 parts antioxidants (1010 and 1682 parts), and 5 parts maleic anhydride-grafted polyolefin. The total mass is 92 parts.

[0084] The preparation steps were the same as in Example 1, with the corresponding temperature and time parameters adjusted to obtain regenerant S3.

[0085] Example 4: Preparation of composite regenerator S4

[0086] Prepare the following materials according to the following mass ratio: 22 parts palm oil asphalt, 30 parts aromatic base oil, 12 parts C5 petroleum resin, 3 parts organosilicon surfactant, 0.8 parts 10100 and 2.4 parts 1682 antioxidants, and 2.8 parts polyfunctional amine compounds. The total mass is 83 parts.

[0087] The preparation steps are the same as in Example 2, and regenerant S4 is obtained.

[0088] Comparative Example 1: Conventional Light Oil Regenerator

[0089] A commercially available common RAP regenerator with lubricating oil fraction as its main component was used. It has a low viscosity and is designated as comparative regenerator D1.

[0090] Comparative Example 2: Interface-free Activator and Penetrant

[0091] The formulation of Example 1 was followed, but without the addition of OP-10 interfacial activator, and its proportions were replaced with an equal amount of naphthenic base oil. Specifically: 30 parts palm oil pitch, 30 parts naphthenic base oil, 18 parts terpene resin, 3 parts antioxidant, and 6 parts compatibilizer. Prepared according to the method of Example 1, this was designated as comparative regenerator D2.

[0092] Comparative Example 3: No compatibility stabilizer

[0093] The formulation of Example 1 was followed, but without the maleic anhydride-grafted polyolefin compatibilizer, and its proportions were replaced with an equal amount of terpene resin. Specifically: 30 parts palm oil asphalt, 25 parts naphthenic base oil, 24 parts terpene resin, 5 parts OP-10, and 3 parts antioxidant. Prepared according to the method of Example 1, this was designated as comparative regenerator D3. Slight uneven thickening was observed after cooling during the preparation process.

[0094] Comparative Example 4: Single Component

[0095] Palm oil bitumen was used directly as a comparative regenerator, denoted as D4.

[0096] Example 5: Test on the recovery effect of recycler on the properties of recycled asphalt in finely separated materials

[0097] 1. Sample preparation:

[0098] Original Asphalt (VA): Fresh 70# road petroleum asphalt of the same grade as that used to produce this RAP section.

[0099] Aged asphalt (AA): Asphalt recovered from the finely separated asphalt aggregate according to the asphalt recovery method in JTGE20-2011T0727. This asphalt represents severely aged asphalt from the finely separated aggregate.

[0100] Preparation of Recycled Asphalt Samples: Simulating the Actual Application Process. First, the finely separated aggregate was heated in an oven at 110℃ for 2 hours. Multiple 1000g portions of preheated aggregate were weighed. Following a fixed admixture ratio of 8% by weight of the aggregate, 80g of different types of recycling agents (S1, S2, S3, S4, D1, D2, D3, D4) preheated at 70℃ were added to each sample. The aggregate and recycling agents were placed in a preheated small asphalt mixing pot and mechanically mixed at 110℃ for 120 seconds. The mixing process ensured that the recycling agents uniformly coated the aggregate.

[0101] The fine aggregate obtained after the above-mentioned mixing and recycling is regarded as recycled asphalt slurry, and asphalt is recovered from it again using the rotary evaporator method. The asphalt obtained in this way is the recycled asphalt after the action of the recycling agent. They are labeled as follows:

[0102] R-S1: Asphalt that has been recycled after being treated with the recycling agent S1 of this invention.

[0103] R-S2: Asphalt that has been recycled after being treated with the recycling agent S2 of this invention.

[0104] R-S3: Asphalt that has been recycled after being treated with the recycling agent S3 of this invention.

[0105] R-S4: Asphalt that has been recycled after being treated with the recycling agent S4 of this invention.

[0106] R-D1: Asphalt that has been treated with comparative recycling agent D1 and then recycled.

[0107] R-D2: Asphalt that has been treated with comparative recycling agent D2 and then recycled.

[0108] R-D3: Asphalt that has been treated with comparative recycling agent D3 and then recycled.

[0109] R-D4: Asphalt that has been treated with comparative recycling agent D4 and then recycled.

[0110] 2. Performance test results:

[0111] Penetration, ductility, softening point, and dynamic viscosity at 60℃ were tested on virgin asphalt (VA), aged asphalt (AA), and various recycled asphalt samples. The results are summarized in Table 1 below.

[0112] Table 1: Comparison of Asphalt Performance Test Results

[0113] Sample number Types of regenerators Penetration (0.1 mm, 25℃) Ductility (cm, 15℃) Softening point (°C) Dynamic viscosity at 60℃ (Pa·s) VA Original asphalt 69 >100 46 180 AA Aged asphalt (non-recycled) 26 20 63.5 1550 R-S1 S1 of the present invention 67 69 49 230 R-S2 S2 of the present invention 65 66 48.5 245 R-S3 S3 of the present invention 62 63 50.5 260 R-S4 S4 of the present invention 70 60 46.5 210 R-D1 Comparative Example D1 (Commercially Available) 52 48 52 410 R-D2 Comparative Example D2 (without penetrant) 58 45 54.5 520 R-D3 Comparative Example D3 (without stabilizer) 64 55 47.5 240 R-D4 Comparative Example D4 (pure plant-based) 48 40 56 580

[0114] 3. Results Analysis:

[0115] (1) Penetration Recovery: All the rejuvenators (S1-S4) of this invention exhibited excellent penetration recovery capabilities, with the recovery values ​​of R-S1 and R-S4 (67 and 70) being very close to the original asphalt (69). This indicates that the rejuvenators of this invention can effectively soften severely aged asphalt and restore its hardness to near the level of new asphalt. In the comparative examples, the commercially available lightweight rejuvenator D1 showed insufficient recovery (52), and the pure plant asphalt D4 performed even worse (48), indicating that single components or simple oils are insufficient to cope with deep aging. The recovery effect of D2 (58) without a penetrant was also weaker than that of this invention, confirming the importance of the interfacial activator in promoting the penetration of the rejuvenator and thus acting on the internal aged asphalt.

[0116] (2) Ductility Recovery: Ductility is a key indicator characterizing the low-temperature toughness and crack resistance of asphalt. The ductility of aged asphalt AA is only 20 cm. The regenerators of this invention, especially S1 and S2, restore the ductility to 69 cm and 66 cm, respectively, with a recovery rate far exceeding that of other comparative samples. This fully demonstrates the synergistic effect of plant-based asphalt / talt asphalt and components such as petroleum resin, which not only softens but also reorganizes and improves the colloidal structure of asphalt, restoring its flexibility. The ductility recovery of samples without penetrant (D2) and without stabilizer (D3) is poor, indicating that good penetration and system stability are prerequisites for deep regeneration and restoration of toughness. The ductility recovery of commercially available D1 and pure plant-based D4 is limited.

[0117] (3) Softening point control: Due to oxidation and hardening, the softening point of aged asphalt AA increases to 63.5℃. Ideally, recycling should restore it to a reasonable range (close to the original asphalt). The softening points of the recycling agents S1, S2, and S4 of this invention are controlled at 49.0℃, 48.5℃, and 46.5℃, respectively, all slightly higher than the original asphalt but within the range of high-quality asphalt, indicating that good high-temperature stability is maintained while restoring flexibility. This is due to the tackifying and compensating effect of the resin components. The softening points of comparative examples D1, D2, and D4 are too high (52-56℃), indicating that the recycled asphalt may be too hard and brittle; the softening point of D3 (without stabilizer) is acceptable, but considering its ductility, the performance is uneven.

[0118] (4) Viscosity recovery at 60℃: Aged asphalt experiences a surge in viscosity due to aging (1550 Pa·s). After recycling, it needs to be reduced to a range suitable for construction and possessing sufficient high-temperature shear resistance. The recycling agents S1-S4 of this invention restore the viscosity to the 210-260 Pa·s range, significantly lower than that of aged asphalt, yet slightly higher than that of the original asphalt, achieving an ideal balance between restoring fluidity and retaining the necessary viscosity. The recycled asphalt of comparative examples D1, D2, and D4 has significantly higher viscosity (410-580 Pa·s), indicating that their recycling process may be insufficient or the component matching may be inappropriate, resulting in the asphalt remaining too viscous, which may affect its workability. The viscosity of D3 is acceptable, but its overall performance is insufficient.

[0119] Conclusion: Considering the four key indicators, the regenerator S1 prepared in Example 1 exhibits the best overall performance balance, and can restore the performance of severely aged asphalt to a state that is closest to that of new asphalt with slightly optimized high-temperature performance.

[0120] In summary, the composite regenerator for fine separation of oil-aggregate in asphalt milling aggregates provided by this invention, along with its preparation method and application, successfully solves the core technical bottlenecks of difficult penetration, poor compatibility, and unsatisfactory regeneration effect of finely separated oil-rich fine aggregates through the scientific design and synergistic compounding of multiple components, including plant asphalt / talt asphalt, petroleum base oil, resin, interface activator, anti-aging agent, and compatibility stabilizer, supplemented by an optimized preparation process. This regenerator can deeply and efficiently restore the physical and rheological properties of severely aged asphalt, enabling it to meet the requirements for high-grade roads. Pretreatment of finely separated aggregates using this regenerator can achieve 100% high-value resource utilization of this most difficult-to-utilize component in RAP, significantly increasing the overall RAP content, reducing road construction costs, and decreasing resource consumption and environmental pollution. It possesses outstanding inventiveness, significant practicality, and broad application prospects.

[0121] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0122] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features of the invention herein.

[0123] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications or equivalent substitutions made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A special regenerator for fine separation of asphalt milling aggregate and asphalt stone, characterized in that, It consists of the following components by mass parts: Vegetable bitumen or tall oil bitumen: 20-45 parts; Petroleum-based recycled base oil: 15-35 parts; Terpene resin or C5 / C9 petroleum resin: 10-25 parts; Interface activator and penetrant: 3-10 parts; Anti-aging agent: 1-5 parts; Compatibility stabilizer: 2-8 parts.

2. The regenerant according to claim 1, characterized in that, The content of the plant-based bitumen or tall oil bitumen is 25-40 parts.

3. The regenerant according to claim 2, characterized in that, The plant-based asphalt is selected from at least one of palm oil asphalt, soybean oil asphalt, or rosin asphalt.

4. The regenerant according to claim 1, characterized in that, The petroleum-based recycled base oil is a naphthenic base oil or an aromatic base oil, and the kinematic viscosity of the petroleum-based recycled base oil at 60°C is 800-2500 mm² / s.

5. The regenerant according to claim 4, characterized in that, The kinematic viscosity of the petroleum-based recycled base oil at 60°C is 1000-2000 mm² / s.

6. The regenerant according to claim 1, characterized in that, The content of the terpene resin or C5 / C9 petroleum resin is 12-22 parts.

7. The regenerant according to claim 1, characterized in that, The interface activator and penetrant is selected from at least one of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, or organosilicon surfactant, and the content of the interface activator and penetrant is 4-8 parts.

8. The regenerant according to claim 1, characterized in that, The anti-aging agent includes hindered phenolic primary antioxidants and phosphite secondary antioxidants, wherein the mass ratio of the primary antioxidant to the secondary antioxidant is 1:1 to 1:

3.

9. The regenerant according to claim 1, characterized in that, The compatibility stabilizer is selected from at least one of maleic anhydride graft polymer, polyfunctional amine compound or organobentonite, and the content of the compatibility stabilizer is 3-6 parts.

10. A method for preparing a special regenerator for fine separation of asphalt milling aggregate and asphalt stone according to any one of claims 1-9, characterized in that, Includes the following steps: a) Mix vegetable bitumen or tall oil bitumen with petroleum-based recycled base oil at 80-110℃ to obtain mixture A; b) Heat mixture A to 120-140℃, add terpene resin or C5 / C9 petroleum resin, and stir until completely melted to obtain mixture B; c) Cool mixture B to 70-90℃, add interfacial activator and penetrant, anti-aging agent and compatibility stabilizer, and perform high-speed shear stirring to obtain homogenized product; d) Cool the homogenized product to room temperature and filter it to obtain the regenerant.

11. The preparation method according to claim 10, characterized in that, In step a), the stirring speed is 200-500 rpm; in step c), after adding all the additives, the speed is increased to 300-600 rpm for the high-speed shear stirring.

12. The application of a recycling agent according to any one of claims 1-9 in the recycling of asphalt pavement recycled materials, characterized in that, The application is for regenerating fine aggregates rich in aged bitumen obtained after fine separation of oilstone.

13. The application according to claim 12, characterized in that, Includes the following steps: S1: Preheat the fine material obtained from the fine separation of oilstone to 100-120°C, and preheat the regenerant to 60-80°C; S2: Weigh 5%-10% of the preheated regenerant by weight of the fine material, and mechanically mix it with the preheated fine material at 100-120°C for at least 90 seconds. S3: Use the uniformly mixed recycled fine aggregates for the preparation of asphalt mixtures.

14. The application according to claim 13, characterized in that, In step S1, the regenerant is preheated to a state where it is easily flowable.

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