Heat-resistant asphalt mixture and preparation method thereof

Abstract

The present invention provides a heat-resistant asphalt mixture and a preparation method thereof, and relates to the field of asphalt technology. The asphalt mixture provided by the present invention includes the following components by weight: 50-60 parts of aggregate, 20-30 parts of aggregate, 10-15 parts of base asphalt, 5-10 parts of modified filler mixture, and 1-5 parts of functional additives; the modified filler mixture includes modified alumina and biphenyl ditelluride, and the preparation method of the modified alumina includes the following steps: the alumina powder is kept at 90-100°C for 2-3h to obtain an activated powder, the activated powder is dispersed in ethyl acetate to obtain a dispersion, a coupling agent is added to the dispersion, and 2,3-difluoropyridine is stirred and reacted, and then filtered out and dried to obtain modified alumina. The present invention can significantly improve the strength and rutting resistance of the asphalt mixture at high temperatures after curing, and improve the crack resistance at low temperatures.

Description

Technical Field

[0001] The invention relates to the technical field of asphalt, and in particular to a temperature-resistant asphalt mixture and a preparation method thereof. Background Art

[0002] Asphalt mixture is a material made of asphalt, mineral materials and fillers in a certain proportion. It is widely used in highway construction. However, with the rapid development of my country's road transportation industry, and heavy loads, multiple axles and large traffic volumes are the main traffic characteristics in my country, traditional asphalt mixtures can no longer meet the needs of high-grade roads. In addition, traditional asphalt mixtures are prone to various problems in high and low temperature environments. For example, they are prone to flow and plastic deformation at high temperatures, resulting in rutting on the surface, and are prone to brittle fracture at low temperatures.

[0003] In order to overcome the defects of traditional asphalt mixtures at high and low temperatures, various temperature-resistant asphalt mixtures have been developed through various modification technologies. For example, polymers such as styrene-butadiene-styrene block copolymers and ethylene-vinyl acetate copolymers are added to asphalt in an attempt to improve the high-temperature stability and low-temperature crack resistance of asphalt. Waste tire rubber powder can also be added to the asphalt, which not only has environmental significance, but also can comprehensively improve the elasticity and durability of the asphalt.

[0004] However, adding high molecular polymers and rubber powder to asphalt will greatly increase the preparation cost of heat-resistant asphalt mixtures. Therefore, in the prior art, nanomaterials and short fibers are often added to asphalt to construct an elastic network in the asphalt to improve the temperature resistance of the asphalt. However, during use, the interface properties between nanomaterials, fiber materials and asphalt are easily affected, thereby affecting the long-term performance of the asphalt mixture. There is an urgent need to provide a solution to improve this problem. Summary of the invention

[0005] The object of the present invention is to provide a temperature-resistant asphalt mixture and a preparation method thereof.

[0006] In a first aspect, the present invention provides a heat-resistant asphalt mixture, which comprises the following components in parts by weight: 50-60 parts of aggregate, 20-30 parts of aggregate, 10-15 parts of base asphalt, 5-10 parts of modified filler mixture, and 1-5 parts of functional additives; the modified filler mixture comprises modified alumina and biphenyl ditelluride, and the preparation method of the modified alumina comprises the following steps: the alumina powder is kept at 90-100°C for 2-3h to obtain an activated powder, the activated powder is dispersed in ethyl acetate to obtain a dispersion, a coupling agent and 2,3-difluoropyridine are added to the dispersion, stirred for reaction, filtered out and dried to obtain the modified alumina; the preparation method of the modified filler mixture comprises: after heating and melting biphenyl ditelluride, the modified alumina is added, ultrasonically mixed under a nitrogen atmosphere, and ground and pulverized after cooling to obtain the modified filler mixture.

[0007] The heat-resistant asphalt mixture provided by the present invention comprises aggregate as the main component, which provides a skeleton structure and main bearing capacity for the solidified asphalt, and provides strength and rigidity for the mixture so that the asphalt mixture can withstand traffic loads. The aggregate can fill the pores between the aggregates, effectively improving the density and stability of the mixture, and can also improve the adhesion between the matrix asphalt and the aggregate, thereby improving the integrity of the mixture. The matrix asphalt can provide adhesion for the mixture, thereby ensuring the bonding strength between the components, and can also provide elasticity and flexibility. After the modified alumina and ditellurium biphenyl are added, the strength and rutting resistance of the asphalt mixture after solidification at high temperatures can be significantly improved, and the crack resistance at low temperatures can be improved.

[0008] Optionally, the alumina powder is pre-ground and passed through a 100-mesh sieve before being kept at 90-100° C. for 2-3 hours.

[0009] Optionally, after the activated powder is dispersed in ethyl acetate to prepare a dispersion, the solid-liquid ratio of the activated powder in the dispersion is 0.06-0.08 g / mL.

[0010] Optionally, when a coupling agent is added to the dispersion and stirred to react with 2,3-difluoropyridine, the mass mixing ratio of the activated powder, the coupling agent and the 2,3-difluoropyridine is 1:(0.1-0.3):(0.5-0.6); wherein the coupling agent includes at least one of KH-560, KH-550 and KH-570.

[0011] Optionally, the mass mixing ratio of the modified alumina to the biphenyl ditellurium in the modified filler mixture is (3-7): (2-3).

[0012] Optionally, after the biphenyl ditelluride is heated and melted, when the modified alumina is added, the mass mixing ratio of the modified alumina to the biphenyl ditelluride is (3-7):(2-3).

[0013] Optionally, the particle size of the modified filler mixture is 5-10 mm.

[0014] Optionally, the aggregate includes one of quartz, eucryptite and gravel.

[0015] Optionally, the aggregate includes fine aggregate with a particle size of 1-10 mm and coarse aggregate with a particle size of 10-20 mm.

[0016] Optionally, the aggregate includes at least one of granite, gravel, and river sand.

[0017] Optionally, the aggregate has a particle size of 5-15 mm.

[0018] Optionally, the base asphalt includes at least one of 50# asphalt, 70# asphalt, and 90# asphalt.

[0019] Optionally, the functional additives include stabilizers, antioxidants, reinforcing agents, and anti-rutting agents.

[0020] Optionally, the stabilizer includes at least one of polyvinyl alcohol, cellulose, and octadecyl phenylpropionate.

[0021] Optionally, the antioxidant includes at least one of octyl diphenyl phosphite, dioctadecyl pentaerythritol diphosphite, and 1,3,5-trimethyl-2,4,6-tri(3,5-tert-butyl-4-hydroxybenzyl)benzene.

[0022] Optionally, the enhancer includes at least one of cardanol, p-toluenesulfonic acid, and isomeric tridecyl alcohol polyoxyethylene ether.

[0023] Optionally, the anti-rutting agent includes one of high-density polyethylene and recycled high-density polyethylene.

[0024] Optionally, 1-5 parts by weight of reinforcing fiber are further included, and the reinforcing fiber includes at least one of carbon fiber, modified basalt fiber and polyester fiber.

[0025] Optionally, the preparation method of the modified basalt fiber includes: soaking the basalt fiber in a sodium hydroxide solution to modify it to obtain hydroxylated fiber; mixing the hydroxylated fiber with SBS resin in a mass ratio of 1:(0.5-0.6), adding sodium dodecyl sulfate, stirring and reacting at 120-150° C., and filtering and separating to obtain the modified basalt fiber.

[0026] In a second aspect, the present invention provides a method for preparing a heat-resistant asphalt mixture, comprising the following steps: heating and mixing aggregate, aggregate and base asphalt to obtain a mixture; adding a modified filler mixture and a functional additive into the mixture and stirring and mixing to obtain an asphalt mixture. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with general skills in the field to which the present invention belongs.

[0028] The present invention provides a temperature-resistant asphalt mixture, which comprises the following components by weight: 50-60 parts of aggregate, 20-30 parts of aggregate, 10-15 parts of base asphalt, 5-10 parts of modified filler mixture, and 1-5 parts of functional additives. In fact, the modified filler mixture comprises modified alumina and biphenyl ditelluride, and specifically, the mass mixing ratio of modified alumina to biphenyl ditelluride is (3-7): (2-3).

[0029] Specifically, the preparation method of modified alumina includes the following steps: keeping alumina powder at 90-100°C for 2-3 hours to obtain activated powder, dispersing the activated powder in ethyl acetate to obtain a dispersion, adding a coupling agent and 2,3-difluoropyridine to the dispersion, stirring and reacting, filtering and drying, and obtaining modified alumina.

[0030] In fact, the preparation method of the modified filler mixture includes: heating and melting biphenyl ditelluride, adding modified alumina, ultrasonically mixing under a nitrogen atmosphere, cooling and grinding, and obtaining a modified filler mixture.

[0031] In some embodiments, the alumina powder is pre-ground and passed through a 100-mesh sieve before being kept at 90-100° C. for 2-3 hours.

[0032] In some embodiments, after the activated powder is dispersed in ethyl acetate to prepare a dispersion, the solid-liquid ratio of the activated powder in the dispersion is 0.06-0.08 g / mL.

[0033] In some embodiments, when a coupling agent and 2,3-difluoropyridine are added to the dispersion and stirred for reaction, the mass mixing ratio of the activated powder, the coupling agent and the 2,3-difluoropyridine is 1:(0.1-0.3):(0.5-0.6); wherein the coupling agent includes at least one of KH-560, KH-550 and KH-570.

[0034] In some embodiments, after biphenyl ditelluride is heated and melted, when modified alumina is added, the mass mixing ratio of the modified alumina to the biphenyl ditelluride is (3-7): (2-3). Specifically, the particle size of the modified filler mixture is 5-10 mm.

[0035] In some embodiments, the aggregate includes one of quartz, eucryptite, and gravel.

[0036] In some embodiments, the aggregate includes fine aggregate with a particle size of 1-10 mm and coarse aggregate with a particle size of 10-20 mm.

[0037] In some embodiments, the aggregate includes at least one of granite, gravel, and river sand.

[0038] In some embodiments, the aggregate has a particle size of 5-15 mm.

[0039] In some embodiments, the base asphalt includes at least one of 50# asphalt, 70# asphalt, and 90# asphalt.

[0040] In some embodiments, the functional additives include stabilizers, antioxidants, enhancers, and anti-rutting agents. Specifically, the stabilizer includes at least one of polyvinyl alcohol, cellulose, and octadecyl phenylpropionate; specifically, the antioxidant includes at least one of octyl diphenyl phosphite, pentaerythritol dioctadecyl diphosphite, and 1,3,5-trimethyl-2,4,6-tris(3,5-tert-butyl-4-hydroxybenzyl)benzene; specifically, the enhancer includes at least one of cardanol, p-toluenesulfonic acid, and isomeric tridecanol polyoxyethylene ether; specifically, the anti-rutting agent includes one of high-density polyethylene and recycled high-density polyethylene.

[0041] In some embodiments, 1-5 parts of reinforcing fiber are also included by weight, and the reinforcing fiber includes at least one of carbon fiber, modified basalt fiber, and polyester fiber. In fact, the preparation method of modified basalt fiber includes: immersing basalt fiber in sodium hydroxide solution to modify it to obtain hydroxylated fiber; mixing hydroxylated fiber with SBS resin in a mass ratio of 1: (0.5-0.6), adding sodium dodecyl sulfate, stirring and reacting at 120-150°C, and filtering and separating to obtain modified basalt fiber.

[0042] In fact, the present invention also provides a method for preparing a heat-resistant asphalt mixture, comprising the following steps: heating and mixing aggregate, aggregate and base asphalt to obtain a mixture; adding a modified filler mixture and a functional additive into the mixture and stirring and mixing to obtain an asphalt mixture.

[0043] Examples 1-5

[0044] Embodiments 1 to 5 of the present invention respectively provide a temperature-resistant asphalt mixture, and the specific components and amounts thereof are shown in Table 1 below.

[0045] Table 1 Components and dosages of Examples 1 to 5

[0046]

[0047] The aggregates used in Examples 1 to 5 are quartz, eucryptite and gravel in a mass ratio of 2:1:1, and the aggregates are mixed to form fine aggregate with an average particle size of 5 mm and coarse aggregate with an average particle size of 15 mm, respectively, and the mass ratio of fine aggregate to coarse aggregate is 1:1.

[0048] The aggregates used in Examples 1 to 5 are granite, gravel, and river sand in a mass ratio of 3:2:1, and the aggregate mixture is ground into a powder with an average particle size of 10 mm; the base asphalt used is 50# asphalt (purchased from Maoming Zhengcheng Petrochemical Co., Ltd.); the stabilizer used is polyvinyl alcohol (purchased from Anhui Wanwei High-tech Materials Co., Ltd., PVA 100-86); the antioxidant used is octyl diphenyl phosphite (CAS No.: 3164-55-4); the enhancer used is cardanol; the anti-rutting agent used is high-density polyethylene (selected from Shanghai Fluoroboshi New Material Technology Co., Ltd., HDPE-DGDA6094).

[0049] The preparation method of the modified filler mixture used in Examples 1 to 5 includes:

[0050] S1, grinding alumina and passing it through a 100-mesh sieve to obtain alumina powder, and then keeping the alumina powder at 95° C. for 2 hours to obtain activated powder;

[0051] S2, dispersing the activated powder in ethyl acetate at a solid-liquid ratio of 0.07 g / mL to prepare a dispersion;

[0052] S3. Add KH-560 (purchased from Xuzhou Yihuiyang New Materials Co., Ltd.) and 2,3-difluoropyridine (CAS No.: 1513-66-2) into the dispersion, stir and react, filter and wash twice with anhydrous ethanol and deionized water, and dry in a 50°C drying oven to constant weight to obtain modified alumina; wherein the mass ratio of activated powder, KH-560 and 2,3-difluoropyridine is 1:0.2:0.5;

[0053] S4. After heating and melting biphenyl ditelluride (CAS No.: 32294-60-3), add modified alumina and mix them ultrasonically under a nitrogen atmosphere. After cooling, grind, crush and sieve to obtain a modified filler mixture with an average particle size of 8 mm.

[0054] The reinforcing fibers used in Examples 3 to 5 are specifically modified basalt fibers, and the preparation method thereof comprises: preparing basalt fibers (purchased from Shandong Taicheng Fiber Co., Ltd., with an average length of 12 mm and a density of 1.3 kg / m 3 , thickness 0.025mm) were immersed in a saturated aqueous solution of sodium hydroxide with a solid-liquid ratio of 0.05g / mL for 1h, filtered, washed three times with deionized water and dried to constant weight to obtain hydroxylated fiber; the hydroxylated fiber was mixed with SBS resin (SBS-4452 purchased from Fujian Gulei Petrochemical Co., Ltd.) at a mass ratio of 1:0.5, and sodium dodecyl sulfate (purchased from Shandong Zhengyu Chemical Technology Co., Ltd., CAS No.: 151-21-3, the mass of which is 1 / 10 of the hydroxylated resin) was added and stirred at 130°C for reaction, then filtered and separated, washed three times with anhydrous ethanol and deionized water, and dried to constant weight to obtain modified basalt fiber.

[0055] The preparation method of the heat-resistant asphalt mixture in Examples 1 to 3 comprises the following steps: heating the base asphalt until it melts, adding aggregate and aggregate in sequence, stirring and mixing to obtain a mixture; adding a modified filler mixture and a functional additive to the mixture, stirring and mixing to obtain an asphalt mixture.

[0056] The preparation method of the heat-resistant asphalt mixture in Example 4 and Example 5 includes the following steps: heating the base asphalt until it melts, adding aggregate and aggregate in sequence, and stirring and mixing to obtain a mixture; adding reinforcing fiber, modified filler mixture and functional additive to the mixture, and stirring and mixing to obtain an asphalt mixture.

[0057] Example 6

[0058] Example 6 of the present invention provides a temperature-resistant asphalt mixture, which is different from Example 4 in that the reinforcing fiber in Example 4 is carbon fiber (chopped carbon fiber purchased from Dongguan Shangyuan Antistatic Plastic Products Co., Ltd., with a fineness of 6-10 mm).

[0059] Example 7

[0060] Example 7 of the present invention provides a temperature-resistant asphalt mixture, which is different from Example 4 in that the reinforcing fiber in Example 7 is polyester fiber (purchased from Wuhan Qixing New Technology Research Institute, with a fiber diameter of 18-65 μm, acid and alkali resistance ≥ 95%, and a density of 0.91 g / cm 3 ).

[0061] Comparative Example 1

[0062] This comparative example 1 provides a temperature-resistant asphalt mixture, which is different from Example 4 in that comparative example 1 does not contain a modified filler mixture, but 7 parts by weight of modified alumina, and the preparation method of the modified alumina is the same as that of Example 4.

[0063] Comparative Example 2

[0064] This comparative example 2 provides a temperature-resistant asphalt mixture, which is different from Example 4 in that comparative example 2 does not contain a modified filler mixture, but 7 parts by mass of aluminum oxide.

[0065] Comparative Example 3

[0066] This comparative example 3 provides a temperature-resistant asphalt mixture, which is different from Example 4 in that comparative example 3 does not contain a modified filler mixture, but 7 parts by weight of ditellurium biphenyl.

[0067] Comparative Example 4

[0068] This comparative example 4 provides a temperature-resistant asphalt mixture, which is different from Example 4 in that comparative example 4 does not contain a modified filler mixture.

[0069] Comparative Example 5

[0070] This comparative example 5 provides a temperature-resistant asphalt mixture, which is different from Example 4 in that the preparation method of the modified filler mixture provided in comparative example 5 includes the following steps: after heating and melting 3 parts by weight of biphenyl ditelluride, 4 parts by weight of alumina powder (passing through a 100-mesh sieve) are added, and ultrasonically mixed under a nitrogen atmosphere, and then cooled and ground, crushed and sieved to obtain a modified filler mixture with an average particle size of 8 mm.

[0071] Performance Testing

[0072] The heat-resistant asphalt mixtures prepared in Examples 1 to 7 and Comparative Examples 1 to 5 were tested for the following items according to the method described in Technical Specifications for Highway Asphalt Pavement Construction (JTG F40-2004). Each test was repeated five times and the average value was taken. The test results are shown in Table 2 below: 25°C needle penetration, mm; softening point, °C; Marshall stability, kN.

[0073] The heat-resistant asphalt mixtures prepared in Examples 1 to 7 and Comparative Examples 1 to 5 were subjected to rutting dynamic stability testing at 60°C and a pressure of 0.7 MPa. The test was repeated five times and the average value was taken. The results are shown in Table 2.

[0074] Table 2 Performance test data

[0075] 25℃ Needle penetration / mm Softening point Marshall stability / kN Rutting stability / mm Example 1 62.4 50.6 8.6 7953.4 Example 2 64.3 51.2 8.7 7998.1 Example 3 69.2 58.6 9.3 8425.8 Example 4 68.5 58.1 9.2 8537.4 Example 5 69.5 57.8 9.3 8512.5 Example 6 65.8 53.6 8.9 8246.9 Example 7 66.7 54.7 9.0 8275.1 Comparative Example 1 43.5 43.6 7.5 7216.5 Comparative Example 2 42.4 43.1 7.4 7152.4 Comparative Example 3 32.8 40.3 7.2 6825.4 Comparative Example 4 33.4 38.5 7.3 6862.7 Comparative Example 5 47.5 46.8 8.1 7851.4

[0076] Although the embodiments of the present invention are described in detail above, it is obvious to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as described in the claims. Moreover, the present invention described herein may have other embodiments and may be implemented or realized in a variety of ways.

Claims

1. A temperature-resistant asphalt mixture, characterized in that: The composition comprises the following components by weight: 50-60 parts of aggregate, 20-30 parts of aggregate, 10-15 parts of base asphalt, 5-10 parts of modified filler mixture, and 1-5 parts of functional additive; The modified filler mixture includes modified alumina and biphenyl ditelluride; The preparation method of modified alumina comprises: preserving alumina powder at 90-100°C for 2-3 hours to obtain activated powder, dispersing the activated powder in ethyl acetate to obtain a dispersion, wherein the solid-liquid ratio of the activated powder in the dispersion is 0.06-0.08 g:1 mL; adding a coupling agent and 2,3-difluoropyridine to the dispersion, stirring and reacting, filtering out and drying, to obtain modified alumina; wherein the mass ratio of the activated powder, the coupling agent and the 2,3-difluoropyridine is 1:(0.1-0.3):(0.5-0.6); the coupling agent comprises at least one of KH-560, KH-550 and KH-570; The preparation method of the modified filler mixture comprises: heating and melting biphenyl ditelluride, adding modified alumina, ultrasonically mixing under a nitrogen atmosphere, cooling and grinding to obtain a modified filler mixture; wherein the mass ratio of the modified alumina to the biphenyl ditelluride is (3-7):(2-3).

2. The temperature-resistant asphalt mixture according to claim 1, characterized in that: Before the alumina powder is kept at 90-100°C for 2-3 hours, the alumina powder is pre-ground and passed through a 100-mesh sieve.

3. The temperature-resistant asphalt mixture according to claim 1, characterized in that: The particle size of the modified filler mixture is 5-10 mm.

4. The temperature-resistant asphalt mixture according to claim 1, characterized in that: The aggregate includes one of quartz, eucryptite and gravel; And / or, the aggregate comprises fine aggregate with a particle size of 1-10 mm and coarse aggregate with a particle size of 10-20 mm; And / or, the aggregate includes at least one of granite, sandstone, and river sand; And / or, the particle size of the aggregate is 5-15 mm; the matrix asphalt includes at least one of 50# asphalt, 70# asphalt, and 90# asphalt.

5. The temperature-resistant asphalt mixture according to claim 1, characterized in that: The functional additive includes at least one of a stabilizer, an antioxidant, a reinforcing agent, and an anti-rutting agent.

6. The temperature-resistant asphalt mixture according to claim 5, characterized in that: The stabilizer includes at least one of polyvinyl alcohol, cellulose, and octadecyl phenylpropionate; And / or, the antioxidant includes at least one of octyl diphenyl phosphite, pentaerythritol dioctadecyl diphosphite, and 1,3,5-trimethyl-2,4,6-tris(3,5-tert-butyl-4-hydroxybenzyl)benzene; And / or, the enhancer includes at least one of cardanol, p-toluenesulfonic acid, and isomeric tridecanol polyoxyethylene ether; And / or, the anti-rutting agent includes one of high-density polyethylene and recycled high-density polyethylene.

7. The temperature-resistant asphalt mixture according to claim 1, characterized in that: The invention also includes 1-5 parts of reinforcing fibers by weight, wherein the reinforcing fibers include at least one of carbon fibers, modified basalt fibers and polyester fibers.

8. The temperature-resistant asphalt mixture according to claim 7, characterized in that: The preparation method of the modified basalt fiber comprises: immersing the basalt fiber in a sodium hydroxide solution to modify it so as to obtain hydroxylated fiber; mixing the hydroxylated fiber with SBS resin at a mass ratio of 1:(0.5-0.6), adding sodium dodecyl sulfate, stirring and reacting at 120-150° C., filtering and separating, and obtaining the modified basalt fiber.

9. A method for preparing a temperature-resistant asphalt mixture as claimed in any one of claims 1 to 4, characterized in that: The method comprises the following steps: heating and mixing aggregate, aggregate and matrix asphalt to obtain a mixture; adding a modified filler mixture and a functional additive into the mixture, stirring and mixing, and obtaining an asphalt mixture.

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