Warm mix high-viscosity asphalt and preparation method thereof

Abstract

The present invention discloses a warm-mix high-viscosity asphalt and a preparation method thereof. The composition of the warm-mix high-viscosity asphalt comprises, by mass, 100 parts of base asphalt, 1-2 parts of a warm-mix modifier, and 2-3 parts of a microcapsule modifier. The base asphalt is heated to 130-140°C, stirred for 15-20 minutes, and then the warm-mix modifier and the microcapsule modifier are added in sequence, and stirring is continued for 20-30 minutes to obtain the warm-mix high-viscosity asphalt. Compared with the prior art, the warm-mix high-viscosity asphalt prepared by the present invention can ensure low viscosity and good construction and workability at high temperatures, which is conducive to mixing, paving and rolling; and after rolling is completed, the viscosity of the asphalt increases rapidly, showing high viscosity characteristics, thereby improving the durability of the road surface. In addition, the preparation method is simple, the conditions are mild, the modifier dosage is low, the cost-effectiveness is high, and it is suitable for large-scale industrial production.

Description

Technical Field

[0001] The present invention belongs to the technical field of road asphalt materials, and in particular relates to a warm-mix high-viscosity asphalt and a preparation method thereof. Background Art

[0002] An ultra-thin wearing layer refers to an anti-skid asphalt wearing layer installed during the construction of new roads or the reconstruction of old roads. It has the characteristics of improving the service performance of the surface layer, beautifying the image of the road and extending its service life. Since the thickness of the asphalt surface layer is relatively thin (<2.5cm), it will not significantly increase the road surface elevation, making it the best choice for preventive maintenance of high-grade highways and the "white to black" conversion of old cement pavements.

[0003] The performance of high-viscosity asphalt is crucial to ensuring the quality of ultra-thin wearing courses. Current applications of high-viscosity asphalt face challenges such as high modifier requirements, complex processing, and high costs; high viscosity at high temperatures, poor workability; and rapid heat loss during paving and rolling, resulting in tight rolling schedules and difficulty in compaction. This can lead to poor impact and scatter resistance in the pavement, and after opening to traffic, widespread defects such as spalling and potholes, impacting pavement performance. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a warm mix high viscosity asphalt and a preparation method thereof.

[0005] The composition of the warm mix high viscosity asphalt includes, by mass, 100 parts of base asphalt, 1-2 parts of warm mix modifier, and 2-3 parts of microcapsule modifier.

[0006] The matrix asphalt is No. 70 asphalt and / or No. 90 asphalt.

[0007] The preparation method of the warm-mix modifier is as follows: polyethylene glycol and a catalyst are mixed, the temperature is raised to 130-140° C., the mixture is stirred for 10-15 minutes, and then epoxy resin is added and reacted for 3-4 hours to obtain the warm-mix modifier.

[0008] The polyethylene glycol is PEG-400, PEG-600 or PEG-800.

[0009] The catalyst is octadecyltrimethylammonium chloride and / or octadecyltrimethylammonium bromide.

[0010] The epoxy resin is E-51, E-44 or E-54.

[0011] The molar ratio of the polyethylene glycol to the epoxy resin is 1:0.9-1; the mass of the catalyst accounts for 2-3% of the total mass of the polyethylene glycol and the epoxy resin.

[0012] The preparation method of the microcapsule modifier comprises: dissolving diisocyanate and core material in an organic solvent to obtain a mixed solution; then dropping the mixed solution into an emulsifier and water under stirring at 1600-2000 r / min, adding diol after the mixed solution droplets are evenly dispersed, continuing the reaction for 1-1.5 hours, and finally vacuum drying to obtain the microcapsule modifier.

[0013] The diisocyanate is TDI, MDI or PAPI.

[0014] The organic solvent is benzene, toluene or carbon tetrachloride.

[0015] The emulsifier is cetyltrimethylammonium chloride and / or cetyltrimethylammonium bromide.

[0016] The diol is 1,2-pentanediol and / or hexanediol.

[0017] The preparation method of the core material is as follows: a chain extender is added dropwise into IPDI, and the reaction is carried out at 30-50° C. for 1-2 hours under nitrogen protection to obtain the core material.

[0018] The chain extender is one of 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA), dimethylthiotoluenediamine (DMTDA), and diethyltoluenediamine (DETDA).

[0019] The molar ratio of the chain extender to IPDI is 1:1.8-2.

[0020] The molar ratio of the diisocyanate to the diol is 1:1-1.1; the mass of the core material accounts for 70-75% of the total mass of the diisocyanate and the diol; the mass of the emulsifier accounts for 1.5-2% of the total mass of the diisocyanate and the core material; the mass of the emulsifier accounts for 2.5-3.5% of the mass of water; and the mass of the organic solvent accounts for 25-30% of the total mass of the diisocyanate and the core material.

[0021] The preparation method of the warm-mix high-viscosity asphalt is as follows: heating the base asphalt to 130-140° C., stirring for 15-20 minutes, then sequentially adding a warm-mix modifier and a microcapsule modifier, and continuing stirring for 20-30 minutes.

[0022] The warm-mix high-viscosity asphalt and its preparation method described herein have the following characteristics: 1) The prepared high-viscosity asphalt contains a warm-mix modifier and a microcapsule modifier, ensuring low viscosity and good workability at high temperatures, facilitating mixing, paving, and compaction. Furthermore, the asphalt can significantly reduce construction temperatures, resulting in the rupture of the capsule wall after compaction, rapidly increasing the asphalt viscosity and exhibiting high viscosity, thus achieving strong adhesion between the asphalt and the aggregate, and between the mixture and the underlying layer, thereby improving pavement durability. 2) The prepared microcapsule modifier is heat-resistant, enabling the capsule wall to rupture after the mixture is compacted, allowing the core material to react with the warm-mix modifier to form a polyurethane-epoxy composite modified asphalt, thereby enhancing the system's bond strength. 3) The prepared warm-mix modifier not only utilizes its hydrophilic and lipophilic groups to reduce the asphalt's high-temperature viscosity, improving workability, but also cross-links with the ruptured microcapsule core material to form a polyurethane-epoxy composite modified asphalt. 4) The preparation method is simple, requires mild conditions, and requires a low modifier dosage, resulting in a high cost-effectiveness and suitability for large-scale industrial production. DETAILED DESCRIPTION

[0023] The warm mix high viscosity asphalt and the preparation method thereof according to the present invention will be further described below with reference to specific embodiments, but the protection scope of the present invention is not limited thereto. Example 1

[0024] Preparation of warm mix modifier:

[0025] PEG-400 and octadecyltrimethylammonium chloride were added to a container, heated to 130°C, and stirred for 15 minutes. Epoxy resin E-51 was then added and allowed to react for 3 hours to obtain a warm-mix modifier. The molar ratio of PEG-400 to epoxy resin E-51 was 1:0.9, and the mass of octadecyltrimethylammonium chloride accounted for 2% of the total mass of PEG-400 and epoxy resin E-51.

[0026] Preparation of microcapsule modifier:

[0027] The chain extender MOCA was added dropwise to IPDI and reacted at 35°C under nitrogen for 1.5 hours to obtain a core material. The molar ratio of the chain extender MOCA to IPDI was 1:1.8.

[0028] ① Dissolve TDI and core material in benzene, stir until uniform, and set aside. ② Add cetyltrimethylammonium chloride and water to a reactor. While stirring at 1800 rpm, slowly drip the prepared mixture from the previous step. Once the mixed solution is evenly dispersed, add 1,2-pentanediol. Continue the reaction for 1 hour, and vacuum dry to obtain a microcapsule modifier sample. The molar ratio of TDI to 1,2-pentanediol is 1:1. The core material accounts for 70% of the total mass of TDI and 1,2-pentanediol; the cetyltrimethylammonium chloride accounts for 1.5% of the total mass of TDI and core material; the cetyltrimethylammonium chloride accounts for 2.6% of the total mass of water; and the benzene accounts for 25% of the total mass of TDI and core material.

[0029] Preparation of warm mix high viscosity asphalt:

[0030] Heat 100 parts of Zhonghai No. 70 asphalt to 135°C and stir for 15 minutes. Then add 1.5 parts of warm mix modifier and 2.5 parts of microcapsule modifier in sequence and stir for 30 minutes. Example 2

[0031] Preparation of warm mix modifier:

[0032] PEG-600 and octadecyltrimethylammonium bromide were added to a container, heated to 135°C, and stirred for 13 minutes. Epoxy resin E-44 was then added and allowed to react for 3 hours to obtain a warm-mix modifier. The molar ratio of PEG-600 to epoxy resin E-44 was 1:1, and the weight of octadecyltrimethylammonium bromide accounted for 3% of the total weight of PEG-600 and epoxy resin E-44.

[0033] Preparation of microcapsule modifier:

[0034] The chain extender DMTDA was added dropwise to IPDI and reacted at 50° C. under nitrogen protection for 1 hour to obtain a core material. The molar ratio of the chain extender DMTDA to IPDI was 1:2.

[0035] ① Dissolve MDI and core material in toluene, stir until uniform, and set aside. ② Add cetyltrimethylammonium bromide and water to a reactor. While stirring at 1600 rpm, slowly drip the prepared mixed solution from the previous step. Once the mixed solution droplets are evenly dispersed, add hexylene glycol. Continue the reaction for 1.5 hours, and vacuum dry to obtain a microcapsule modifier sample. The molar ratio of MDI to hexylene glycol is 1:1.1. The core material accounts for 70% of the total mass of MDI and hexylene glycol; the cetyltrimethylammonium bromide accounts for 1.6% of the total mass of MDI and core material; the cetyltrimethylammonium bromide accounts for 3.0% of the total mass of water; and the toluene accounts for 27% of the total mass of MDI and core material.

[0036] Preparation of warm mix high viscosity asphalt:

[0037] Heat 100 parts of Zhonghai No. 90 base asphalt to 130℃ and stir for 15 minutes. Then add 1 part of warm mix modifier and 3 parts of microcapsule modifier in sequence and stir for 20 minutes. Example 3

[0038] Preparation of warm mix modifier:

[0039] PEG-800 and octadecyltrimethylammonium chloride were added to a container, heated to 140°C, and stirred for 10 minutes. Epoxy resin E-54 was then added and allowed to react for 3 hours to produce a warm-mix modifier. The molar ratio of PEG-800 to epoxy resin E-54 was 1:1, and the mass of octadecyltrimethylammonium chloride accounted for 2.5% of the total mass of PEG-800 and epoxy resin E-54.

[0040] Preparation of microcapsule modifier:

[0041] The chain extender DETDA was added dropwise to IPDI and reacted at 50° C. under nitrogen protection for 1 hour to obtain a core material. The molar ratio of the chain extender DETDA to IPDI was 1:1.8.

[0042] ① Dissolve PAPI and core material in carbon tetrachloride, stir until uniform, and set aside. ② Add cetyltrimethylammonium chloride and water to a reactor. While stirring at 2000 rpm, slowly drip the prepared mixture from the previous step. Once the mixed solution is evenly dispersed, add 1,2-pentanediol. Continue the reaction for 1.5 hours, and dry under vacuum to obtain a microcapsule modifier sample. The molar ratio of PAPI to 1,2-pentanediol is 1:1.1. The core material accounts for 75% of the total mass of PAPI and 1,2-pentanediol; the cetyltrimethylammonium chloride accounts for 2% of the total mass of PAPI and core material; the cetyltrimethylammonium chloride accounts for 3.1% of the total mass of water; and the carbon tetrachloride accounts for 30% of the total mass of PAPI and core material.

[0043] Preparation of warm mix high viscosity asphalt:

[0044] Heat 100 parts of Zhenhai No. 70 base asphalt to 140°C and stir for 15 minutes. Then add 2 parts of warm mix modifier and 2 parts of microcapsule modifier in sequence and stir for 20 minutes. Example 4

[0045] Preparation of warm mix modifier:

[0046] PEG-400 and octadecyltrimethylammonium bromide were added to a container, heated to 130°C, and stirred for 15 minutes. Epoxy resin E-51 was then added and allowed to react for 3 hours to obtain a warm-mix modifier. The molar ratio of PEG-400 to epoxy resin E-51 was 1:0.95, and the mass of octadecyltrimethylammonium bromide accounted for 2% of the total mass of PEG-400 and epoxy resin E-51.

[0047] Preparation of microcapsule modifier:

[0048] The chain extender MOCA was added dropwise to IPDI and reacted for 2 hours at 30°C under nitrogen protection to obtain a core material. The molar ratio of the chain extender MOCA to IPDI was 1:1.8.

[0049] ① Dissolve TDI and core material in toluene, stir until uniform, and set aside. ② Add cetyltrimethylammonium bromide and water to a reactor. While stirring at 2000 rpm, slowly drip the prepared mixture from the previous step. Once the mixed solution is evenly dispersed, add hexylene glycol. Continue the reaction for 1.5 hours, and dry under vacuum to obtain a microcapsule modifier sample. The molar ratio of TDI to hexylene glycol is 1:1.1. The core material accounts for 75% of the total mass of TDI and hexylene glycol; the cetyltrimethylammonium bromide accounts for 1.8% of the total mass of TDI and core material; the cetyltrimethylammonium bromide accounts for 3.3% of the total mass of water; and the toluene accounts for 30% of the total mass of TDI and core material.

[0050] Preparation of warm mix high viscosity asphalt:

[0051] Heat 100 parts of Zhenhai No. 90 base asphalt to 140°C and stir for 17 minutes, then add 1.5 parts of warm mix modifier and 2.3 parts of microcapsule modifier in sequence and stir for 25 minutes.

[0052] After the microcapsules in the warm-mix, high-viscosity asphalt prepared in Examples 1-4 were destroyed, their dynamic viscosity at 60°C was measured and compared with that of asphalt modified with a commercially available high-viscosity modifier (10% blend) and asphalt modified with a commercially available SBS (5% blend). Using graded AC-13 as an example, the warm-mix, high-viscosity asphalt prepared in Examples 1-4, asphalt modified with a commercially available high-viscosity modifier, and asphalt modified with a commercially available SBS were compacted with stone at different temperatures to determine their warm-mix performance. The test results are shown in the table below.

[0053] Asphalt performance comparison table

[0054]

[0055] The above tests were conducted in accordance with the "Testing Procedures for Asphalt and Asphalt Mixtures for Highway Engineering" (JTG E20-2011). The test results show that the warm-mix, high-viscosity asphalt prepared in the examples of the present invention can reduce its compaction temperature by 30-40°C compared to asphalt modified with commercially available high-viscosity modifiers and SBS-modified asphalt, resulting in better workability and facilitating mixing, paving, and compaction. Furthermore, its dynamic viscosity at 60°C is greater than 580,000 Pa.s, significantly higher than that of asphalt modified with commercially available high-viscosity modifiers and SBS-modified asphalt. In summary, the warm-mix, high-viscosity asphalt prepared in the examples exhibits excellent warm-mix and high-viscosity properties.

[0056] The description and application of the present invention here are illustrative and are not intended to limit the scope of the present invention to the above-mentioned embodiments. Therefore, the present invention is not limited to this embodiment, and any technical solution obtained by equivalent replacement is within the scope of protection of the present invention.

Claims

1. A warm mix high viscosity asphalt, characterized in that: The composition of the warm mix high viscosity asphalt includes, by mass, 100 parts of base asphalt, 1-2 parts of warm mix modifier, and 2-3 parts of microcapsule modifier; The preparation method of the warm mix modifier is as follows: polyethylene glycol and a catalyst are mixed, the temperature is raised to 130-140° C., the mixture is stirred for 10-15 minutes, and then epoxy resin is added and reacted for 3-4 hours to obtain the warm mix modifier; The preparation method of the microcapsule modifier comprises: dissolving diisocyanate and core material in an organic solvent to obtain a mixed solution; then, under stirring at 1600-2000 r / min, dripping the mixed solution into an emulsifier and water, adding a diol after the mixed solution droplets are evenly dispersed, continuing the reaction for 1-1.5 hours, and finally vacuum drying to obtain the microcapsule modifier; The preparation method of the core material comprises: adding a chain extender dropwise into IPDI, reacting at 30-50° C. for 1-2 hours under nitrogen protection, thereby obtaining the core material; the chain extender is one of 3,3'-dichloro-4,4'-diaminodiphenylmethane, dimethylthiotoluenediamine, and diethyltoluenediamine; and the molar ratio of the chain extender to IPDI is 1:1.8-2.

2. The warm mix high viscosity asphalt according to claim 1, characterized in that: The polyethylene glycol is PEG-400, PEG-600 or PEG-800; the catalyst is octadecyltrimethylammonium chloride and / or octadecyltrimethylammonium bromide; and the epoxy resin is E-51, E-44 or E-54.

3. The warm mix high viscosity asphalt according to claim 2, characterized in that: The molar ratio of the polyethylene glycol to the epoxy resin is 1:0.9-1; the mass of the catalyst accounts for 2-3% of the total mass of the polyethylene glycol and the epoxy resin.

4. The warm mix high viscosity asphalt according to claim 1, characterized in that: The diisocyanate is TDI, MDI or PAPI; the organic solvent is benzene, toluene or carbon tetrachloride; the emulsifier is cetyltrimethylammonium chloride and / or cetyltrimethylammonium bromide; and the diol is 1,2-pentanediol and / or hexanediol.

5. The warm mix high viscosity asphalt according to claim 1, characterized in that: The molar ratio of the diisocyanate to the diol is 1:1-1.1; the mass of the core material accounts for 70-75% of the total mass of the diisocyanate and the diol; the mass of the emulsifier accounts for 1.5-2% of the total mass of the diisocyanate and the core material; the mass of the emulsifier accounts for 2.5-3.5% of the mass of water; and the mass of the organic solvent accounts for 25-30% of the total mass of the diisocyanate and the core material.

6. The method for preparing warm mix high viscosity asphalt according to any one of claims 1 to 5, characterized in that: The specific operation of the preparation method is: heating the matrix asphalt to 130-140° C., stirring for 15-20 minutes, then adding the warm mix modifier and the microcapsule modifier in sequence, and continuing to stir for 20-30 minutes.

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