Warm-mixing high-dosage waste asphalt regenerant and preparation method thereof

Abstract

The invention provides a warm-mixing high-dosage waste asphalt regenerant and a preparation method thereof. The warm-mixing high-dosage waste asphalt regenerant comprises the following components: 20-40% of aromatic oil component, 20-40% of waste asphalt component, 20-40% of waste asphalt component and 20-40 5-20% of a vegetable oil component; 2-8% of polyethylene wax; 1-3% of a nonionic surfactant; 3 to 10 percent of organic bentonite; 0.1 to 1% of a silane coupling agent; 0.05 to 0.5 percent of an antioxidant; and the balance of carrier oil. According to the warm-mixing high-mixing-amount waste asphalt regenerant and the preparation method thereof, various high-quality raw materials such as the aromatic oil, the vegetable oil and the polyethylene wax are adopted, and the emulsifying property, the lubricating property and the ageing resistance of the regenerant can be effectively improved by combining the optimal proportion of the nonionic surfactant and the organic bentonite, so that the service life of asphalt is prolonged, and the high-temperature stability of the asphalt is improved. According to the preparation method disclosed by the invention, by accurately controlling the temperature, the shearing speed and the vacuum degassing process, uniform dispersion and full reaction of each component are ensured, so that the overall performance and the production efficiency of the regenerant are improved.

Description

Technical Field

[0001] The invention relates to the technical field of road engineering materials and preparation thereof, in particular to a warm-mix high-volume waste asphalt regeneration agent and a preparation method thereof. Background Art

[0002] In the field of road engineering, in order to save resources and reduce environmental pollution, the recycling of waste asphalt pavement materials has become an important direction for highway maintenance and resurfacing. The traditional hot mix asphalt process requires heating the asphalt and aggregate to above 150°C, which not only has high energy consumption and large exhaust emissions, but also significantly increases the viscosity of the mixture at high dosages, affecting construction mixing and paving smoothness. In recent years, warm mix asphalt technology has gradually been used in low-dosage RAP and new asphalt mixtures because it can reduce the mixing temperature by more than 20°C, significantly reducing energy consumption and harmful gas emissions, while improving the construction environment. Commonly used warm mix additives on the market are mostly organic surfactants, mineral powders or synthetic polymers, which mainly reduce the mixing temperature by reducing the viscosity of asphalt and improving wettability.

[0003] However, when the content of waste asphalt pavement material exceeds 50%, existing warm-mix additives are ineffective in activating the aged asphalt components, making it difficult to fully restore its bonding and ductility. This results in difficult mixing and poor stability of the mixture, and is prone to defects such as oil separation, premature rutting, and low-temperature cracking during construction. To address these issues, there is an urgent need to develop a warm-mix, high-content waste asphalt pavement regeneration agent and its preparation method that can effectively activate aged asphalt at relatively low temperatures, while being both cost-effective and easy to prepare. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a warm-mix high-dosage waste asphalt regeneration agent and a preparation method thereof, which solves the problem that the existing warm-mix additives have insufficient activation effect on aged asphalt components.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a warm mix high-dosage waste asphalt regeneration agent, comprising:

[0006] Aromatic oil components: 20–40%;

[0007] Vegetable oil fraction: 5–20%;

[0008] Polyethylene wax: 2–8%;

[0009] Nonionic surfactant: 1–3%;

[0010] Organobentonite: 3–10%;

[0011] Silane coupling agent: 0.1–1%;

[0012] Antioxidants: 0.05–0.5%;

[0013] Carrier oil: Balance.

[0014] Preferably, the aromatic oil component is petroleum distillate, preferably 25-35%.

[0015] Preferably, the average molecular weight of the polyethylene wax is 2000-3000.

[0016] Preferably, the nonionic surfactant is fatty alcohol polyoxyethylene ether, and the hydrophilic-oil tolerant balance value is 8-12.

[0017] Preferably, the silane coupling agent is γ-aminopropyltriethoxysilane.

[0018] A method for preparing a warm-mix high-dosage waste asphalt regeneration agent comprises the following steps: S1. weighing 20-40% of an aromatic oil component and a carrier oil to a total of 50-60% by weight, stirring at 80-90° C. for 10-15 minutes to form a homogeneous base oil phase;

[0019] S2. 3–10% of organic bentonite was gradually added to the homogeneous base oil phase and dispersed at a high shear speed of 3000–5000 r / min-1 for 15–30 min to fully expand the interlayer spacing of the bentonite to form a nano-scale lamellar dispersion system;

[0020] S3. Lower the temperature to 70 ± 5°C and sequentially add 5–20% of the vegetable oil component and 2–8% of the polyethylene wax. Continue shearing until the polyethylene wax is completely melted and the system becomes transparent.

[0021] S4. Add 1–3% nonionic surfactant, 0.1–1% silane coupling agent, and 0.05–0.5% antioxidant sequentially at 60–65°C. Stir magnetically for 10–20 minutes. Degas under vacuum at –0.08–0.1 MPa for 5–10 minutes to complete the interfacial activation reaction and remove bubbles.

[0022] S5. Filter the degassed mixture through a 40–60 μm filter, cool it to ≤40°C, and then seal and fill it to obtain a warm-mix high-dosage waste asphalt regeneration agent.

[0023] Preferably, the high-speed shear dispersion in S2 adopts a rotor-stator disperser, wherein the rotor tip speed of the rotor-stator disperser is 10-20 m / s and the energy input is 5-10 kWh / t, so as to ensure that the bentonite layers are completely peeled off.

[0024] Preferably, the degassing process in S4 comprises the following steps:

[0025] S4.1. The magnetically stirred mixture is placed in a vacuum degassing tank with a gas phase excess of about 20%, and the tank lid and all flange connections are sealed;

[0026] S4.2. Connect the vacuum port on the top of the vacuum degassing tank to a vacuum pump. Adjust the air inlet valve to gradually reduce the pressure in the tank to -0.08 MPa to -0.10 MPa over 1–2 minutes. Maintain this negative pressure for 5–10 minutes to allow bubbles in the mixture to escape.

[0027] S4.3. After turning off the vacuum pump, slowly fill the tank with nitrogen to normal pressure, loosen the tank cover valve and take out the degassed regeneration agent.

[0028] The present invention provides a warm mix high dosage waste asphalt regeneration agent and its preparation method.

[0029] Beneficial effects:

[0030] This warm-mix, high-dosage waste asphalt regeneration agent and its preparation method use a variety of high-quality raw materials such as aromatic oil, vegetable oil, polyethylene wax, etc., combined with an optimized ratio of non-ionic surfactant and organic bentonite, which can effectively improve the emulsification, lubricity and anti-aging ability of the regeneration agent, thereby increasing the life and high-temperature stability of asphalt.

[0031] The preparation method of the present invention ensures uniform dispersion and sufficient reaction of all components through precise control of temperature, shear rate, and vacuum degassing, thereby improving the overall performance and production efficiency of the regeneration agent. This regeneration agent is not only adaptable to various complex environmental conditions but also environmentally friendly, suitable for high-yield regeneration of temperature-mixed asphalt, effectively reducing energy consumption and production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] Example 1

[0035] like Figure 1 As shown, an embodiment of the present invention provides a warm-mix high-dosage waste asphalt regeneration agent and a preparation method thereof, comprising: an aromatic oil component: 2%, wherein the aromatic oil component is a petroleum distillate oil, preferably 25%.

[0036] Vegetable oil component: 5%.

[0037] Polyethylene wax: 2–%, the average molecular weight of polyethylene wax is 2000–3000.

[0038] Nonionic surfactant: 1%, the nonionic surfactant is fatty alcohol polyoxyethylene ether, and the hydrophilic-tolerance oil balance value is 8-12.

[0039] Organic bentonite: 3%.

[0040] Silane coupling agent: 0.1%, the silane coupling agent is γ-aminopropyltriethoxysilane.

[0041] Antioxidant: 0.05%.

[0042] Carrier oil: Balance.

[0043] A method for preparing a warm-mix high-dosage waste asphalt regeneration agent comprises the following steps: S1. Weighing 2-40% of an aromatic oil component and a carrier oil to a total of 50% by weight, stirring at 80-90° C. for 10-15 minutes to form a homogeneous base oil phase.

[0044] S2. Gradually add 3% organic bentonite to the homogeneous base oil phase and disperse at a high-speed shear rate of 3000–5000 r·min⁻¹ for 15 minutes to fully expand the interlayer spacing of the bentonite to form a nano-scale lamellar dispersion system. High-speed shear dispersion is performed using a rotor-stator disperser with a rotor tip speed of 20 m / s and an energy input of 10 kWh / t to ensure complete exfoliation of the bentonite interlayers.

[0045] S3. Lower the temperature to 70°C, add 5% of the vegetable oil component and 2% of the polyethylene wax in sequence, and continue shearing until the polyethylene wax is completely melted and the system becomes transparent.

[0046] S4. 1–3% nonionic surfactant, 0.1% silane coupling agent, and 0.05% antioxidant were added sequentially at 60–65°C. After magnetic stirring for 10 minutes, the mixture was degassed under a vacuum of –0.08 for 5 minutes to complete the interfacial activation reaction and remove bubbles. The degassing process in S4 includes the following steps:

[0047] S4.1. Place the magnetically stirred mixture into a vacuum degassing tank with a gas phase excess of approximately 20%, and seal the tank lid and all flange connections.

[0048] S4.2. Connect the vacuum port on the top of the vacuum degassing tank to a vacuum pump. Adjust the air inlet valve to gradually reduce the pressure in the tank to -0.08 MPa within 1 minute. Maintain this negative pressure for 5 minutes to allow the bubbles in the mixture to fully escape.

[0049] S4.3. After turning off the vacuum pump, slowly fill the tank with nitrogen to normal pressure, loosen the tank cover valve and take out the degassed regeneration agent.

[0050] S5. Filter the degassed mixture through 40 μm, cool it to ≤40°C, and then seal and fill it to obtain a warm-mix high-dosage waste asphalt regeneration agent.

[0051] Example 2

[0052] like Figure 1 As shown, an embodiment of the present invention provides a warm-mix high-dosage waste asphalt regeneration agent and a preparation method thereof, comprising: an aromatic oil component: 30%, wherein the aromatic oil component is petroleum distillate oil, preferably 30%.

[0053] Vegetable oil component: 10%.

[0054] Polyethylene wax: 6%, the average molecular weight of polyethylene wax is 2000-3000.

[0055] Nonionic surfactant: 1–3%. The nonionic surfactant is fatty alcohol polyoxyethylene ether with a hydrophilic-tolerance oil balance value of 8–12.

[0056] Organic bentonite: 7%.

[0057] Silane coupling agent: 0.5%, the silane coupling agent is γ-aminopropyltriethoxysilane.

[0058] Antioxidant: 0.1%.

[0059] Carrier oil: Balance.

[0060] Example 3

[0061] like Figure 1 As shown, an embodiment of the present invention provides a warm-mix high-dosage waste asphalt regeneration agent and a preparation method thereof, comprising: an aromatic oil component: 40%, wherein the aromatic oil component is a petroleum distillate oil, preferably 25-35%.

[0062] Vegetable oil component: 20%.

[0063] Polyethylene wax: 8%, the average molecular weight of polyethylene wax is 2000-3000.

[0064] Nonionic surfactant: 3%, the nonionic surfactant is fatty alcohol polyoxyethylene ether, and the hydrophilic-tolerance oil balance value is 8-12.

[0065] Organic bentonite: 10%.

[0066] Silane coupling agent: 1%, the silane coupling agent is γ-aminopropyltriethoxysilane.

[0067] Antioxidant: 0.5%.

[0068] Carrier oil: Balance.

[0069]

[0070]

[0071] Example 1: Due to the low proportion of aromatic oil and vegetable oil components, the cost is low and it is suitable for conventional waste nuclear weapons regeneration applications with high cost requirements. However, its antioxidant, emulsification and environmental performance are weak, making it suitable for general low-demand applications.

[0072] Example 2: This method provides a balanced performance and cost, and is suitable for applications requiring high performance in the regeneration of waste cervix. It has good antioxidant properties, emulsification effects, and environmental friendliness, making it suitable for medium- to long-term use.

[0073] Example 3: This product offers the best performance, particularly in high-temperature, high-intensity environments, and is suitable for applications requiring the highest regeneration performance. While more expensive, its oxidation resistance, emulsification, and stability are superior to the other two examples, making it suitable for applications requiring environmental protection.

[0074] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A warm mix high dosage waste asphalt regeneration agent, characterized in that: include: Aromatic oil components: 20–40%; Vegetable oil fraction: 5–20%; Polyethylene wax: 2–8%; Nonionic surfactant: 1–3%; Organobentonite: 3–10%; Silane coupling agent: 0.1–1%; Antioxidants: 0.05–0.5%; Carrier oil: Balance.

2. The warm-mix high-dosage waste asphalt regeneration agent according to claim 1, characterized in that: The aromatic oil component is petroleum distillate oil, preferably 25-35%.

3. The warm-mix high-dosage waste asphalt regeneration agent according to claim 1, characterized in that: The average molecular weight of the polyethylene wax is 2000-3000.

4. The warm-mix high-dosage waste asphalt regeneration agent according to claim 1, characterized in that: The nonionic surfactant is fatty alcohol polyoxyethylene ether, and the hydrophilic-tolerance oil balance value is 8-12.

5. The warm-mix high-dosage waste asphalt regeneration agent according to claim 1, characterized in that: The silane coupling agent is γ-aminopropyltriethoxysilane.

6. A method for preparing a warm-mix high-dosage waste asphalt regeneration agent, characterized in that: The following steps are involved: S1. Weigh 20–40% of the aromatic oil component and the carrier oil to a total of 50–60% by weight, and stir at 80–90°C for 10–15 minutes to form a homogeneous base oil phase; S2. Gradually add 3–10% organic bentonite to the homogeneous base oil phase and rotate at 3000–5000 r / min. -1 High-speed shear dispersion for 15–30 min; S3. Lower the temperature to 70 ± 5°C and sequentially add 5–20% of the vegetable oil component and 2–8% of the polyethylene wax. Continue shearing until the polyethylene wax is completely melted and the system becomes transparent. S4. Add 1–3% nonionic surfactant, 0.1–1% silane coupling agent, and 0.05–0.5% antioxidant in sequence at 60–65°C, stir magnetically for 10–20 minutes, and then degas under vacuum at –0.08–0.1 MPa for 5–10 minutes. S5. Filter the degassed mixture through a 40–60 μm filter, cool it to ≤40°C, and then seal and fill it to obtain a warm-mix high-dosage waste asphalt regeneration agent.

7. The method for preparing a warm-mix high-volume waste asphalt regeneration agent according to claim 6, characterized in that: The high-speed shear dispersion in S2 uses a rotor-stator disperser, wherein the rotor tip speed of the rotor-stator disperser is 10-20 m / s and the energy input is 5-10 kWh / t.

8. The method for preparing a warm-mix high-dosage waste asphalt regeneration agent according to claim 6, characterized in that: The degassing process described in S4 comprises the following steps: S4.

1. The magnetically stirred mixture is placed in a vacuum degassing tank with a gas phase excess of about 20%, and the tank lid and all flange connections are sealed; S4.

2. Connect the vacuum port on the top of the vacuum degassing tank to a vacuum pump. Adjust the air inlet valve to gradually reduce the pressure in the tank to -0.08 MPa to -0.10 MPa over 1-2 minutes. Maintain this negative pressure for 5-10 minutes. S4.

3. After turning off the vacuum pump, slowly fill the tank with nitrogen to normal pressure, loosen the tank cover valve and take out the degassed regeneration agent.

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