Anti-aging low-carbon asphalt mixture and preparation method thereof

Abstract

The application relates to an anti-aging low-carbon asphalt mixture and a preparation method thereof. The anti-aging low-carbon asphalt mixture comprises the following components in parts by weight: 75-85 parts of aggregate; 10-15 parts of SBS modified asphalt; 8-10 parts of methyl vinyl phenyl silicone rubber; 3-5 parts of kaolin; and 3-6 parts of blocked polyisocyanate; wherein the kaolin is pretreated by maleic anhydride grafting polyethylene. The preparation method comprises the following steps: S1, mixing the SBS modified asphalt and the methyl vinyl phenyl silicone rubber, uniformly stirring after heating to 90-95 DEG C, and obtaining initial mixture; S2, adding the aggregate and the kaolin into the initial mixture and uniformly mixing; S3, adding the blocked isocyanate into the mixture in S2, uniformly stirring after heating to 130-135 DEG C, continuously stirring, and obtaining the anti-aging low-carbon asphalt mixture after the stirring is stopped. The asphalt mixture has excellent anti-aging performance.

Description

Technical Field

[0001] This application relates to the field of asphalt, and in particular to an anti-aging low-carbon asphalt mixture and its preparation method. Background Technology

[0002] Asphalt is a high-molecular polymer widely used as a binder in road engineering. Due to its advantages such as good smoothness, convenient maintenance, simple construction, and low noise, asphalt pavement has become a major type of road surface. However, over long-term use, asphalt pavement will experience aging, resulting in ruts, loosening, potholes, and other defects, leading to deterioration in pavement performance and a shortened service life. To adapt to the rapid development of my country's road transport industry, higher requirements must be placed on the performance of asphalt pavement. Summary of the Invention

[0003] To improve the anti-aging performance of asphalt pavement, this application provides an anti-aging low-carbon asphalt mixture and its preparation method.

[0004] In a first aspect, this application provides an anti-aging low-carbon asphalt mixture, which adopts the following technical solution:

[0005] An anti-aging low-carbon asphalt mixture comprises the following components in parts by weight:

[0006] 75-85 parts aggregate;

[0007] 10-15 parts of SBS modified bitumen;

[0008] 8-10 parts of methyl vinyl phenyl silicone rubber;

[0009] 3-5 parts of kaolin;

[0010] 3-6 parts of blocked polyisocyanate;

[0011] The kaolin is pretreated with maleic anhydride-grafted polyethylene.

[0012] By adopting the above technical solutions, SBS modified asphalt exhibits good high-temperature resistance, low-temperature resistance, strong rutting resistance, excellent fatigue resistance, and superior adhesion. The layered structure of kaolin can absorb lightweight components in asphalt, limiting their volatilization, and also blocking oxygen propagation within the system, inhibiting the oxidative condensation reaction of asphalt, thereby improving its anti-aging properties. The high adsorption capacity of methyl vinyl phenyl silicone rubber can adsorb kaolin, which, as a physical crosslinking point in the system, promotes the mixing of methyl vinyl phenyl silicone rubber and SBS modified asphalt. Simultaneously, the maleic anhydride-grafted polyethylene on the surface of kaolin promotes the compatibility between kaolin and SBS modified asphalt, further enhancing the mixing of methyl vinyl phenyl silicone rubber and SBS modified asphalt. Blocked polyisocyanates can release isocyanate groups at certain temperatures. These isocyanate groups can crosslink with asphalt to form a network structure and can also react with the active groups in methyl vinyl phenyl silicone rubber, further strengthening the connection between methyl vinyl phenyl silicone rubber and SBS modified asphalt, thus enhancing the performance of the asphalt mixture.

[0013] Preferably, the pretreatment method of kaolin is as follows: activated kaolin and maleic anhydride grafted polyethylene are melt-extruded at a weight ratio of 1:(1-2) at an extrusion temperature of 150-170℃, and then granulated to obtain kaolin.

[0014] Preferably, the kaolin activation method is as follows: kaolin is added to a mixed acid with a solid-liquid ratio of 1:(23-25) and soaked for 45-50 hours to obtain activated kaolin. The mixed acid is composed of formic acid and citric acid mixed in a weight ratio of 1:(1-2).

[0015] By adopting the above technical solution, kaolin is first activated with acid to increase the active groups on the surface of kaolin, thereby better promoting the reaction between kaolin and maleic anhydride-grafted polyethylene.

[0016] Preferably, the blocked polyisocyanate is a blocked aliphatic polyisocyanate.

[0017] By adopting the above technical solutions, aliphatic polyisocyanates have better light stability and chemical resistance, which can improve the anti-aging properties of asphalt mixtures to a certain extent.

[0018] Preferably, the vinyl content in the methyl vinyl phenyl silicone rubber is 0.16%-0.2%.

[0019] By adopting the above technical solution, the appropriate vinyl content can ensure that methyl vinyl phenyl silicone rubber has good crosslinking density and aging resistance, thereby effectively ensuring that asphalt mixture has better anti-aging properties.

[0020] Preferably, the aggregate comprises basalt powder, mineral powder and lignin fiber in a weight ratio of (10-15):(8-10):1.

[0021] Preferably, the lignin fiber is pretreated, specifically by mixing lignin fiber, dopamine hydrochloride solution and Tris-HCl buffer solution for reaction, centrifuging and drying to obtain lignin fiber.

[0022] By adopting the above technical solutions, lignin fibers can improve the viscosity, durability, and crack resistance of asphalt. By treating lignin fibers with dopamine, a polydopamine film is formed on the surface of the lignin fibers, which can improve the dispersion of lignin fibers in asphalt. At the same time, the polydopamine film contains phenolic hydroxyl and amino active groups, which crosslink with the active groups in asphalt and even the isocyanate groups released by blocked isocyanates, thereby further improving the compatibility between lignin fibers and asphalt, and greatly improving the performance of asphalt.

[0023] Secondly, this application provides a method for preparing an anti-aging low-carbon asphalt mixture, which adopts the following technical solution:

[0024] A method for preparing an anti-aging low-carbon asphalt mixture includes the following steps:

[0025] S1. Mix SBS modified asphalt and methyl vinyl phenyl silicone rubber, heat to 90-95℃, stir evenly to obtain the initial mixture;

[0026] S2. Add the aggregate and kaolin to the initial mixture and mix well;

[0027] S3. Add the blocked isocyanate to the mixture in S2, stir and mix well, heat to 130-135℃, continue stirring, and after completion, the anti-aging low-carbon asphalt mixture is obtained.

[0028] By adopting the above technical solution, the raw materials are mixed in steps, which helps to fully mix the raw materials.

[0029] In summary, this application includes at least one of the following beneficial technical effects:

[0030] 1. This application utilizes maleic anhydride-grafted polyethylene to treat kaolin, and then combines the roles of SBS modified asphalt, methyl vinyl phenyl silicone rubber, and blocked polyisocyanate in the system to enable the raw materials in the system to be fully dispersed and form a network structure, thereby effectively improving the anti-aging performance of asphalt mixtures.

[0031] 2. The asphalt mixture in this application is simple to prepare, environmentally friendly and convenient to construct, and the asphalt pavement formed after construction has good anti-aging properties. Detailed Implementation

[0032] The present application will be further described in detail below with reference to the embodiments.

[0033] The sources of raw materials in this application are as follows: SBS modified bitumen was purchased from Zhejiang Weike New Materials; blocked aliphatic polyisocyanate was purchased from Guangzhou Haoyi New Materials, model B-830S; basalt powder was purchased from Shandong Zhanfei Construction, with a specification of 10-15mm; mineral powder was purchased from Lingshou County Chengming Mineral Products, with a specification of 325 mesh; lignin fiber was purchased from Taian Hongfa New Materials, with a specification of 0.2mm; and maleic anhydride grafted polyethylene was purchased from Dongguan Caihua Plastics Technology, model HH4101ZVGQI9.

[0034] Preparation Example 1

[0035] Formic acid and citric acid were mixed in a 1:1 weight ratio to prepare a mixed acid. Kaolin was added to the mixed acid with a solid-liquid ratio of 1:23 and soaked for 45 hours. After filtration, activated kaolin was obtained. Activated kaolin and maleic anhydride-grafted polyethylene were added to an extruder in a 1:1 weight ratio and extruded at 150°C. After extrusion, the mixture was granulated to obtain kaolin.

[0036] Preparation Example 2

[0037] Formic acid and citric acid were mixed in a weight ratio of 1:2 to prepare a mixed acid. Kaolin was added to the mixed acid with a solid-liquid ratio of 1:25 and soaked for 48 hours. After filtration, activated kaolin was obtained. Activated kaolin and maleic anhydride-grafted polyethylene were added to an extruder in a weight ratio of 1:2 and extruded at a temperature of 170°C. After extrusion, the mixture was granulated to obtain kaolin.

[0038] Preparation Example 3

[0039] Take a 2 g / L dopamine hydrochloride solution and a Tris-HCl buffer solution with a pH of 8, mix the two solutions, and add lignin fibers. The amount of lignin fibers added to the solution is 1 g / L. React for 1 hour, and then centrifuge and dry to obtain lignin fibers.

[0040] Example 1

[0041] An anti-aging low-carbon asphalt mixture comprises 75 kg of aggregate, 13 kg of SBS modified asphalt, 9 kg of methyl vinyl phenyl silicone rubber, 3 kg of kaolin (as in Preparation Example 1), and 4 kg of closed-cell aliphatic polyisocyanate; wherein the aggregate is composed of basalt powder, mineral powder, and lignin fiber in a weight ratio of 10:8:1; and the vinyl content of the methyl vinyl phenyl silicone rubber is 0.16%.

[0042] In the preparation process, SBS modified asphalt and methyl vinyl phenyl silicone rubber are first mixed, heated to 90°C, and stirred until homogeneous to obtain a preliminary mixture; aggregate and kaolin are added to the preliminary mixture, and stirring is continued until homogeneous; finally, closed aliphatic polyisocyanate is added, heated to 130°C, and stirred until homogeneous to obtain an anti-aging low-carbon asphalt mixture.

[0043] Example 2

[0044] An anti-aging low-carbon asphalt mixture comprises 85 kg of aggregate, 15 kg of SBS modified asphalt, 8 kg of methyl vinyl phenyl silicone rubber, 5 kg of kaolin (as in Preparation Example 1), and 6 kg of closed-cell aliphatic polyisocyanate; wherein the aggregate is composed of basalt powder, mineral powder, and lignin fiber in a weight ratio of 10:8:1; and the vinyl content of the methyl vinyl phenyl silicone rubber is 0.16%.

[0045] In the preparation process, SBS modified asphalt and methyl vinyl phenyl silicone rubber are first mixed, heated to 95°C, and stirred until homogeneous to obtain a preliminary mixture; aggregate and kaolin are added to the preliminary mixture, and stirring is continued until homogeneous; finally, closed aliphatic polyisocyanate is added, heated to 135°C, and stirred until homogeneous to obtain an anti-aging low-carbon asphalt mixture.

[0046] Example 3

[0047] An anti-aging low-carbon asphalt mixture comprises 80 kg of aggregate, 10 kg of SBS modified asphalt, 10 kg of methyl vinyl phenyl silicone rubber, 4 kg of kaolin (as in Preparation Example 1), and 3 kg of closed-cell aliphatic polyisocyanate; wherein the aggregate is composed of basalt powder, mineral powder, and lignin fiber in a weight ratio of 10:8:1; and the vinyl content of the methyl vinyl phenyl silicone rubber is 0.16%.

[0048] In the preparation process, SBS modified asphalt and methyl vinyl phenyl silicone rubber are first mixed, heated to 95°C, and stirred until homogeneous to obtain a preliminary mixture; aggregate and kaolin are added to the preliminary mixture, and stirring is continued until homogeneous; finally, closed aliphatic polyisocyanate is added, heated to 135°C, and stirred until homogeneous to obtain an anti-aging low-carbon asphalt mixture.

[0049] Example 4

[0050] An anti-aging low-carbon asphalt mixture comprises 75 kg of aggregate, 13 kg of SBS modified asphalt, 9 kg of methyl vinyl phenyl silicone rubber, 3 kg of kaolin (as in Preparation Example 2), and 4 kg of closed-cell aliphatic polyisocyanate; wherein the aggregate is composed of basalt powder, mineral powder, and lignin fiber in a weight ratio of 10:8:1; and the vinyl content of the methyl vinyl phenyl silicone rubber is 0.16%.

[0051] In the preparation process, SBS modified asphalt and methyl vinyl phenyl silicone rubber are first mixed, heated to 95°C, and stirred until homogeneous to obtain a preliminary mixture; aggregate and kaolin are added to the preliminary mixture, and stirring is continued until homogeneous; finally, closed aliphatic polyisocyanate is added, heated to 135°C, and stirred until homogeneous to obtain an anti-aging low-carbon asphalt mixture.

[0052] Example 5

[0053] An anti-aging low-carbon asphalt mixture comprises 75 kg of aggregate, 13 kg of SBS modified asphalt, 9 kg of methyl vinyl phenyl silicone rubber, 3 kg of kaolin (as in Preparation Example 1), and 4 kg of closed-cell aliphatic polyisocyanate; wherein the aggregate is composed of basalt powder, mineral powder, and lignin fiber in a weight ratio of 10:8:1; and the vinyl content of the methyl vinyl phenyl silicone rubber is 0.2%.

[0054] In the preparation process, SBS modified asphalt and methyl vinyl phenyl silicone rubber are first mixed, heated to 95°C, and stirred until homogeneous to obtain a preliminary mixture; aggregate and kaolin are added to the preliminary mixture, and stirring is continued until homogeneous; finally, closed aliphatic polyisocyanate is added, heated to 135°C, and stirred until homogeneous to obtain an anti-aging low-carbon asphalt mixture.

[0055] Example 6

[0056] An anti-aging low-carbon asphalt mixture comprises 75 kg of aggregate, 13 kg of SBS modified asphalt, 9 kg of methyl vinyl phenyl silicone rubber, 3 kg of kaolin (as in Preparation Example 1), and 4 kg of closed-cell aliphatic polyisocyanate; wherein the aggregate is composed of basalt powder, mineral powder, and lignin fiber in a weight ratio of 15:10:1; and the vinyl content of the methyl vinyl phenyl silicone rubber is 0.16%.

[0057] In the preparation process, SBS modified asphalt and methyl vinyl phenyl silicone rubber are first mixed, heated to 90°C, and stirred until homogeneous to obtain a preliminary mixture; aggregate and kaolin are added to the preliminary mixture, and stirring is continued until homogeneous; finally, closed aliphatic polyisocyanate is added, heated to 130°C, and stirred until homogeneous to obtain an anti-aging low-carbon asphalt mixture.

[0058] Example 7

[0059] An anti-aging low-carbon asphalt mixture comprises 75 kg of aggregate, 13 kg of SBS modified asphalt, 9 kg of methyl vinyl phenyl silicone rubber, 3 kg of kaolin (as in Preparation Example 1), and 4 kg of closed-cell aliphatic polyisocyanate; wherein the aggregate is composed of basalt powder, mineral powder, and lignin fiber in a weight ratio of 5:5:1; and the vinyl content of the methyl vinyl phenyl silicone rubber is 0.16%.

[0060] In the preparation process, SBS modified asphalt and methyl vinyl phenyl silicone rubber are first mixed, heated to 90°C, and stirred until homogeneous to obtain a preliminary mixture; aggregate and kaolin are added to the preliminary mixture, and stirring is continued until homogeneous; finally, closed aliphatic polyisocyanate is added, heated to 130°C, and stirred until homogeneous to obtain an anti-aging low-carbon asphalt mixture.

[0061] Example 8

[0062] An anti-aging low-carbon asphalt mixture comprises 75 kg of aggregate, 13 kg of SBS modified asphalt, 9 kg of methyl vinyl phenyl silicone rubber, 3 kg of kaolin (as in Preparation Example 1), and 4 kg of closed-cell aliphatic polyisocyanate; wherein the aggregate is composed of basalt powder, mineral powder, and lignin fiber in a weight ratio of 10:8:1, and the lignin fiber is prepared by Preparation Example 3; the vinyl content of the methyl vinyl phenyl silicone rubber is 0.16%.

[0063] In the preparation process, SBS modified asphalt and methyl vinyl phenyl silicone rubber are first mixed, heated to 90°C, and stirred until homogeneous to obtain a preliminary mixture; aggregate and kaolin are added to the preliminary mixture, and stirring is continued until homogeneous; finally, closed aliphatic polyisocyanate is added, heated to 130°C, and stirred until homogeneous to obtain an anti-aging low-carbon asphalt mixture.

[0064] Comparative Example 1

[0065] An anti-aging low-carbon asphalt mixture comprises 75 kg of aggregate, 13 kg of SBS modified asphalt, 9 kg of methyl vinyl phenyl silicone rubber, 3 kg of kaolin, and 4 kg of closed-cell aliphatic polyisocyanate; wherein the aggregate is composed of basalt powder, mineral powder, and lignin fiber in a weight ratio of 10:8:1; and the vinyl content of the methyl vinyl phenyl silicone rubber is 0.16%.

[0066] In the preparation process, SBS modified asphalt and methyl vinyl phenyl silicone rubber are first mixed, heated to 90°C, and stirred until homogeneous to obtain a preliminary mixture; aggregate and kaolin are added to the preliminary mixture, and stirring is continued until homogeneous; finally, closed aliphatic polyisocyanate is added, heated to 130°C, and stirred until homogeneous to obtain an anti-aging low-carbon asphalt mixture.

[0067] Comparative Example 2

[0068] An anti-aging low-carbon asphalt mixture comprises 78 kg of aggregate, 13 kg of SBS modified asphalt, 9 kg of methyl vinyl phenyl silicone rubber, and 4 kg of closed-cell aliphatic polyisocyanate; wherein the aggregate is composed of basalt powder, mineral powder, and lignin fiber in a weight ratio of 10:8:1; and the vinyl content of the methyl vinyl phenyl silicone rubber is 0.16%.

[0069] In preparation, SBS modified asphalt and methyl vinyl phenyl silicone rubber are first mixed, heated to 90°C, and stirred until homogeneous to obtain a preliminary mixture; aggregates are added to the preliminary mixture and stirred until homogeneous; finally, closed aliphatic polyisocyanate is added, heated to 130°C, and stirred until homogeneous to obtain an anti-aging low-carbon asphalt mixture.

[0070] Comparative Example 3

[0071] An anti-aging low-carbon asphalt mixture includes 84 kg of aggregate, 13 kg of SBS modified asphalt, 3 kg of kaolin (as in Preparation Example 1), and 4 kg of closed aliphatic polyisocyanate; wherein the aggregate is composed of basalt powder, mineral powder, and lignin fiber in a weight ratio of 10:8:1.

[0072] During preparation, SBS modified asphalt is first heated to 90°C; then aggregate and kaolin are added and stirred until homogeneous; finally, closed aliphatic polyisocyanate is added, heated to 130°C, and stirred until homogeneous to obtain anti-aging low-carbon asphalt mixture.

[0073] Performance testing

[0074] The road performance of the asphalt mixtures in each embodiment and comparative example was tested in accordance with JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering". In addition, the aging of the asphalt mixtures in each embodiment and comparative example after 30 days and 60 days of use at 80°C was measured. The result of Comparative Example 1 after 30 days of use at 80°C was set as 1. The results of other embodiments and comparative examples were compared with the results of Comparative Example 1. The specific results are shown in the table below.

[0075] Table 1 Performance Test Results

[0076]

[0077] Referring to Table 1, compared with Comparative Examples 1-3, the asphalt mixture in this application has better performance and better anti-aging properties. This indicates that by using maleic anhydride-grafted polyethylene to treat kaolin, the dispersibility and compatibility of kaolin in the system can be improved. At the same time, the network structure formed by methyl vinyl phenyl silicone rubber and blocked isocyanate in the system can further enhance the performance and anti-aging properties of the asphalt mixture.

[0078] Combining Examples 1 and 5, a suitable vinyl content can ensure that methyl vinyl phenyl silicone rubber has good crosslinking density and aging resistance, thereby effectively ensuring that asphalt mixture has superior anti-aging properties.

[0079] Combining Examples 1, 6, and 7, blending basalt powder, mineral powder, and lignin fiber in appropriate proportions can better improve the strength, durability, and anti-aging properties of asphalt mixtures. Furthermore, combining Example 8, forming a polydopamine film on the surface of the lignin fiber can further improve the performance and anti-aging properties of the asphalt mixture.

[0080] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An anti-aging low-carbon asphalt mixture, characterized in that: Includes the following components by weight: 75-85 parts aggregate; 10-15 parts of SBS modified bitumen; 8-10 parts of methyl vinyl phenyl silicone rubber; 3-5 parts of kaolin; 3-6 parts of blocked polyisocyanate; Among them, the kaolin is pre-treated with maleic anhydride grafted with polyethylene; The pretreatment method of kaolin is as follows: activated kaolin and maleic anhydride grafted polyethylene are melt-extruded at a weight ratio of 1:(1-2) at an extrusion temperature of 150-170℃, and then granulated. The activation method of kaolin is as follows: Kaolin is put into a mixed acid with a solid-liquid ratio of 1:(23-25) and soaked for 45-50 hours to obtain activated kaolin. The mixed acid is composed of formic acid and citric acid mixed in a weight ratio of 1:(1-2).

2. The anti-aging low-carbon asphalt mixture according to claim 1, characterized in that: Blocked polyisocyanates are blocked aliphatic polyisocyanates.

3. The anti-aging low-carbon asphalt mixture according to claim 1, characterized in that: The vinyl content in methyl vinyl phenyl silicone rubber is 0.16%-0.2%.

4. The anti-aging low-carbon asphalt mixture according to claim 1, characterized in that: The aggregate consists of basalt powder, mineral powder and lignin fiber in a weight ratio of (10-15):(8-10):

1.

5. The anti-aging low-carbon asphalt mixture according to claim 4, characterized in that: The lignin fiber is pretreated by mixing lignin fiber, dopamine hydrochloride solution and Tris-HCl buffer solution, reacting them, centrifuging and drying to obtain lignin fiber.

6. A method for preparing an anti-aging low-carbon asphalt mixture according to any one of claims 1-5, characterized in that: Includes the following steps: S1. Mix SBS modified asphalt and methyl vinyl phenyl silicone rubber, heat to 90-95℃, stir evenly to obtain the initial mixture; S2. Add the aggregate and kaolin to the initial mixture and mix well; S3. Add the closed-type polyisocyanate to the mixture in S2, stir and mix well, heat to 130-135℃, continue stirring, and after completion, the anti-aging low-carbon asphalt mixture is obtained.

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