Asphalt modifier, its preparation method and application

Abstract

The application provides an asphalt modifier and a preparation method and application thereof, and particularly relates to the technical field of road asphalt pavement materials.The asphalt modifier comprises the following raw materials in parts by weight: 10-15 parts of modified sodium alginate-chitosan compound, 5-8 parts of modified fiber, 1-3 parts of polyvinyl alcohol-poly (methyl methacrylate) copolymer and 1-3 parts of styrene-maleic anhydride copolymer.The asphalt modifier is prepared by compounding four substances, i.e., modified fiber, modified sodium alginate-chitosan compound, polyvinyl alcohol-poly (methyl methacrylate) copolymer and styrene-maleic anhydride copolymer, and the four substances are synergistic with each other, so that the high and low temperature performance and the anti-creep performance of the asphalt are significantly improved, the stability and durability are improved, the asphalt mixture has good mechanical properties and road performance, the crack resistance is improved, the flowability and workability are improved, the service life of the asphalt and the asphalt mixture is prolonged, and the application prospect is good.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road asphalt pavement materials, in particular to an asphalt modifier and a preparation method and application thereof. BACKGROUND

[0002] In order to improve the pavement performance of traditional matrix asphalt, it is currently the most important way to obtain high-performance asphalt by modifying matrix asphalt with a modifier. For example, patent CN110511574A discloses a lignin asphalt modifier composed of soluble lignin, insoluble lignin, residual oil and / or vegetable oil in a mass ratio of (5-30):(10-57):(40-13). The lignin asphalt modifier has the advantages of improving the ductility and softening point of asphalt and reducing the penetration of asphalt when added to 5-15% of matrix asphalt. However, the preparation process of the lignin modifier in this scheme is complex, and the energy consumption and cost are high. At the same time, the other performances of the asphalt material obtained by this method are still defective. Patent CN1537894A discloses a preparation method of a high-temperature storage stable polymer modified asphalt material for road paving. The method is to pre-mix a thermoplastic elastomer polystyrene-polybutadiene-polystyrene triblock copolymer and a stabilizer silicate inorganic filler to obtain a modified asphalt masterbatch, and then mix the modified masterbatch into matrix asphalt with high shear. However, this method involves petroleum chemical raw materials, which is not sustainable and has high cost. Patent CN104073003A proposes a road asphalt modifier and a preparation method to improve the performance of traditional modifiers. The preparation method includes mixing coal, waste tire slices and catalytic cracking oil slurry according to the precise mass ratio, then adding coal liquefaction catalyst metal elements, and reacting at a temperature of 350-450℃ for 1-6 hours to obtain the target road modifier. However, the high-temperature reaction condition and the complex catalytic cracking oil slurry preparation process of this method result in high production cost, which limits its long-term use.

[0003] Therefore, it is necessary to develop an environmentally friendly and high-performance asphalt modifier to meet the required mechanical properties and pavement performance, and to expand the ideas of asphalt modification, which has practical significance. SUMMARY

[0004] In view of this, the present application provides an asphalt modifier and a preparation method and application thereof.

[0005] The technical scheme of the present application is as follows:

[0006] An asphalt modifier, according to weight parts, includes the following raw materials: 10-15 parts of modified sodium alginate-chitosan compound, 5-8 parts of modified fiber, 1-3 parts of polyvinyl alcohol-poly (methyl methacrylate) copolymer and 1-3 parts of styrene-maleic anhydride copolymer.

[0007] Further, the preparation method of the modified sodium alginate-chitosan composite comprises:

[0008] (1) adding chitosan into a basic methanol-DMF solution, adding (3-mercaptopropyl) trimethoxysilane and mixing uniformly, performing hydrothermal reaction, cooling, washing, and drying to obtain an intermediate product;

[0009] (2) adding the intermediate product, polyvinyl alcohol, and sodium alginate into water, performing ultrasonic treatment, adding a calcium chloride solution for crosslinking, washing for several times, and vacuum freeze-drying to obtain the modified sodium alginate-chitosan composite.

[0010] Further, in step (1), the solid-liquid ratio of the chitosan to the basic methanol-DMF solution is 1:6-10 g / mL;

[0011] The basic methanol-DMF solution is a sodium hydroxide-methanol-DMF solution, and the concentration is 30-40 wt%, wherein the volume ratio of methanol to DMF is 1:1-3;

[0012] The adding amount of the (3-mercaptopropyl) trimethoxysilane is 0.1-0.2 of the weight of the chitosan;

[0013] The hydrothermal reaction is performed at 160-180℃ for 6-10 h.

[0014] Further, in step (2), the mass ratio of the intermediate product, polyvinyl alcohol, and sodium alginate is 1:5-7:1-2; and the solid-liquid ratio of the intermediate product to water is 1:10-20 g / mL;

[0015] The ultrasonic treatment is performed at 30-40 kHz and 50-70℃ for 2-3 h;

[0016] The concentration of the calcium chloride solution is 2-5 wt%, and the adding amount is 0.3-0.5 of the volume of water.

[0017] Further, the preparation method of the modified fiber comprises: mixing basalt fiber with ionic liquid, and then performing plasma treatment to obtain a modified fiber.

[0018] The modification of the fiber surface can improve the fiber reinforcing effect, can enhance the interaction between the fiber and the asphalt, improve the wettability of the fiber, and provide stable chemical bonds for the fiber and the asphalt. The stable chemical bonds help to enhance the interface strength, which is conducive to the asphalt material to avoid damage caused by temperature changes and other harsh environments.

[0019] Further, the ionic liquid is 1-octyl-3-methylimidazolium hexafluorophosphate ionic liquid; and the mass ratio of the basalt fiber to the ionic liquid is 5-7:1.

[0020] The plasma treatment is performed at 60-100 W, 20-30 kHz for 20-30 min.

[0021] The application provides a preparation method of an asphalt modifier.

[0022] The modified fiber, the modified sodium alginate-chitosan compound, the polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer are mixed in water, dried to obtain mixture particles, and the mixture particles are sent into a double-screw extruder to be extruded to obtain the asphalt modifier.

[0023] Further, the water is added in an amount of 3-5 times the total weight of the modified fiber, the modified sodium alginate-chitosan compound, the polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer.

[0024] The application further provides application of the asphalt modifier in asphalt.

[0025] Further, the asphalt modifier is added in asphalt in a mass percentage of 3-6%.

[0026] Compared with the prior art, the application has the following beneficial effects:

[0027] 1. The modified sodium alginate-chitosan compound is grafted with (3-mercapto propyl) trimethoxysilane to form a crosslinked network structure, and the mercapto silane is introduced to enhance the interfacial compatibility of the sodium alginate-chitosan compound, solve the poor dispersibility of chitosan in asphalt, improve the tackifying effect of asphalt, enhance the adhesion of asphalt and aggregate, enhance the pavement performance, and improve the high-temperature rut resistance and low-temperature anti-cracking performance of asphalt.

[0028] 2. The basalt fiber is treated by specific ionic liquid plasma to introduce active groups on the surface of the fiber, enhance the bonding capacity of the fiber and asphalt, improve the adhesion of asphalt and aggregate in asphalt mixture, improve the crack resistance and fatigue resistance of asphalt, improve the stability of asphalt, and prolong the service life of asphalt mixture.

[0029] 3. The polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer enhance the compatibility of the asphalt modifier and asphalt, significantly enhance the high-temperature resistance and stability of asphalt, and prolong the service life of asphalt mixture.

[0030] 4. The asphalt modifier of the present application is prepared by compounding four substances, modified fiber, modified sodium alginate-chitosan compound, polyvinyl alcohol-poly (methyl methacrylate) copolymer and styrene-maleic anhydride copolymer, which are synergistic with each other, significantly improving the high and low temperature performance, creep resistance, stability and durability of asphalt, making the asphalt mixture have good mechanical properties and road performance, improving the crack resistance, improving the flowability and workability, prolonging the service life of asphalt and asphalt mixture, and having good application prospect. DETAILED DESCRIPTION

[0031] In order to better understand the technical content of the present application, specific examples are provided below to further illustrate the present application.

[0032] The experimental methods used in the embodiments of the present application are all conventional methods unless otherwise specified.

[0033] The materials, reagents and the like used in the embodiments of the present application can be obtained from commercial channels unless otherwise specified.

[0034] The polyvinyl alcohol-poly (methyl methacrylate) copolymer of the present application is purchased from Xi'an Rixi Biological Technology Co., Ltd., and the average molecular weight is 13000.

[0035] The styrene-maleic anhydride copolymer of the present application is purchased from Tiancheng Chemical (Jiangsu) Co., Ltd., and the number average molecular weight is 4000 Da.

[0036] Example 1

[0037] The asphalt modifier of the present application, according to parts by weight, includes the following raw materials: 13g of modified sodium alginate-chitosan compound, 6g of modified fiber, 2g of polyvinyl alcohol-poly (methyl methacrylate) copolymer and 2g of styrene-maleic anhydride copolymer.

[0038] The preparation method of the above-mentioned modified sodium alginate-chitosan compound includes:

[0039] (1) According to the solid-liquid ratio of 1:8 g / mL, chitosan is added into 35wt% sodium hydroxide-methanol-DMF solution (volume ratio of methanol: DMF = 1:2) and stirred, then (3-mercaptopropyl) trimethoxysilane is added, the mass ratio of (3-mercaptopropyl) trimethoxysilane to chitosan is 0.15:1, after mixing uniformly, hydrothermal reaction is carried out in a reaction kettle at 170℃ for 8h, cooled, washed with deionized water, and dried to obtain an intermediate product;

[0040] (2) The intermediate product, polyvinyl alcohol and sodium alginate are added into water, the solid-liquid ratio of the intermediate product and water is 1:15 g / mL, ultrasonic treatment is carried out at 35 kHz and 60℃ for 2 h, 5 wt% calcium chloride solution with a volume of 0.4 times that of water is added for crosslinking, then deionized water is washed, and vacuum freeze drying is carried out to obtain the modified sodium alginate-chitosan composite.

[0041] The preparation method of the modified fiber comprises the following steps: basalt fibers and 1-octyl-3-methylimidazolium hexafluorophosphate ionic liquid are mixed at a mass ratio of 6:1, and then treated in a plasma device, specifically, treated at 80 W and 25 kHz for 25 min to obtain the modified fiber.

[0042] The preparation method of the asphalt modifier of the embodiment comprises the following specific steps:

[0043] The modified fiber, the modified sodium alginate-chitosan composite, the polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer are added into water, the water is added in an amount of 4 times the total weight of the modified fiber, the modified sodium alginate-chitosan composite, the polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer, mixed at 1200 rpm for 25 min, dried at 70℃ for 12 h to obtain the mixture particles, and the mixture particles are sent into a double-screw extruder for extrusion to obtain the asphalt modifier.

[0044] Example 2

[0045] The asphalt modifier of the embodiment comprises the following raw materials in parts by weight: 10 g of the modified sodium alginate-chitosan composite, 5 g of the modified fiber, 1 g of the polyvinyl alcohol-poly (methyl methacrylate) copolymer and 1 g of the styrene-maleic anhydride copolymer.

[0046] The preparation method of the modified sodium alginate-chitosan composite comprises the following steps:

[0047] (1) Chitosan is added into a 30 wt% sodium hydroxide-methanol-DMF solution (the volume ratio of methanol:DMF is 1:1) according to a solid-liquid ratio of 1:6 g / mL, then (3-mercaptopropyl) trimethoxysilane is added, the mass ratio of (3-mercaptopropyl) trimethoxysilane to chitosan is 0.1:1, the mixture is uniformly mixed, then hydrothermal reaction is carried out in a reaction kettle at 160℃ for 6 h, cooled, washed with deionized water and dried to obtain the intermediate product;

[0048] (2) The intermediate product, polyvinyl alcohol and sodium alginate are added into water, the solid-liquid ratio of the intermediate product and water is 1:10 g / mL, ultrasonic treatment is carried out at 30 kHz and 50℃ for 2 h, 5 wt% calcium chloride solution with a volume of 0.3 times that of water is added for crosslinking, then deionized water is washed, and vacuum freeze drying is carried out to obtain the modified sodium alginate-chitosan composite.

[0049] The preparation method of the modified fiber comprises the following steps: basalt fibers and 1-octyl-3-methylimidazolium hexafluorophosphate ionic liquid are mixed at a mass ratio of 5:1, and then treated in a plasma device, specifically, treated at 60 W and 20 kHz for 20 min to obtain the modified fiber.

[0050] The preparation method of the asphalt modifier of the embodiment comprises the following specific steps:

[0051] The modified fiber, the modified sodium alginate-chitosan composite, the polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer are added into water, the water is added in an amount of 3 times the total weight of the modified fiber, the modified sodium alginate-chitosan composite, the polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer, mixed at 1000 rpm for 20 min, dried at 70℃ for 12 h to obtain the mixture particles, and the mixture particles are sent into a double-screw extruder for extrusion to obtain the asphalt modifier.

[0052] Embodiment 3

[0053] The asphalt modifier of the embodiment comprises the following raw materials in parts by weight: 15 g of the modified sodium alginate-chitosan composite, 8 g of the modified fiber, 3 g of the polyvinyl alcohol-poly (methyl methacrylate) copolymer and 3 g of the styrene-maleic anhydride copolymer.

[0054] The preparation method of the modified sodium alginate-chitosan composite comprises the following steps:

[0055] (1) Chitosan is added into a 40 wt% sodium hydroxide-methanol-DMF solution (the volume ratio of methanol to DMF is 1:3) according to a solid-liquid ratio of 1:10 g / mL, then (3-mercaptopropyl) trimethoxysilane is added, the mass ratio of (3-mercaptopropyl) trimethoxysilane to chitosan is 0.2:1, the mixture is uniformly mixed, then hydrothermal reaction is carried out in a reaction kettle at 180℃ for 10 h, cooled, washed with deionized water and dried to obtain the intermediate product;

[0056] (2) The intermediate product, polyvinyl alcohol and sodium alginate are added into water, the solid-liquid ratio of the intermediate product and water is 1:20 g / mL, ultrasonic treatment is carried out at 40 kHz and 70°C for 3 h, 5 wt% calcium chloride solution with a volume of 0.5 times of water is added for crosslinking, then deionized water is washed, and vacuum freeze drying is carried out to obtain the modified sodium alginate-chitosan composite.

[0057] The preparation method of the modified fiber includes: mixing basalt fibers with a mass ratio of 7:1 and 1-octyl-3-methylimidazolium hexafluorophosphate ionic liquid, and treating in a plasma device, specifically: treating at 100 W and 30 kHz for 30 min to obtain the modified fiber.

[0058] The preparation method of the asphalt modifier of the embodiment includes the following specific steps:

[0059] The modified fiber, the modified sodium alginate-chitosan composite, the polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer are added into water, the water is added in an amount of 5 times the total weight of the modified fiber, the modified sodium alginate-chitosan composite, the polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer, mixed at 1500 rpm for 30 min, dried at 70°C for 12 h to obtain the mixture particles, and the mixture particles are sent into a double-screw extruder for extrusion to obtain the asphalt modifier.

[0060] Comparative Example 1

[0061] The difference between the embodiment 1 and the comparative example 1 is that the modified sodium alginate-chitosan composite is absent, and the other conditions are the same as those of the embodiment 1.

[0062] That is, the preparation method of the asphalt modifier of the comparative example 1 includes the following specific steps:

[0063] The preparation method of the modified fiber includes: mixing basalt fibers with a mass ratio of 6:1 and 1-octyl-3-methylimidazolium hexafluorophosphate ionic liquid, and treating in a plasma device, specifically: treating at 80 W and 25 kHz for 25 min to obtain the modified fiber.

[0064] The preparation method of the asphalt modifier of the comparative example 1 includes the following specific steps:

[0065] The modified fiber, the polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer are added into water, the water is added in an amount of 4 times the total weight of the modified fiber, the polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer, mixed at 1200 rpm for 25 min, dried at 70℃ for 12 h, to obtain mixture particles, and the mixture particles are sent into a double screw extruder for extrusion to obtain the asphalt modifier.

[0066] Comparative Example 2

[0067] The difference between the present comparative example and Example 1 is that the sodium alginate-chitosan complex is not modified, and the other conditions are the same as those in Example 1.

[0068] The asphalt modifier of the present comparative example comprises the following raw materials in parts by weight: 13 g of sodium alginate-chitosan complex, 6 g of modified fiber, 2 g of polyvinyl alcohol-poly (methyl methacrylate) copolymer and 2 g of styrene-maleic anhydride copolymer.

[0069] The preparation method of the above-mentioned sodium alginate-chitosan complex comprises:

[0070] (1) The sodium alginate is added into deionized water, and stirred at 60℃ for 2 h until the sodium alginate is completely dissolved, to prepare a sodium alginate solution with a mass concentration of 1%;

[0071] (2) The chitosan is added into the sodium alginate solution, and the mass ratio of the chitosan to the sodium alginate is 1:2, a 5 wt% calcium chloride solution with a volume of 0.4 times that of the sodium alginate solution is added for crosslinking, then washed with deionized water, and dried at 60℃ to obtain the sodium alginate-chitosan complex.

[0072] The preparation method of the above-mentioned modified fiber comprises: mixing basalt fiber and 1-octyl-3-methylimidazolium hexafluorophosphate ionic liquid at a mass ratio of 6:1, and treating in a plasma device, specifically: treating at 80 W, 25 kHz for 25 min to obtain the modified fiber.

[0073] The preparation method of the asphalt modifier of the present comparative example comprises the following steps:

[0074] The modified fiber, the sodium alginate-chitosan complex, the polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer are added into water, the water is added in an amount of 4 times the total weight of the modified fiber, the modified sodium alginate-chitosan complex, the polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer, mixed at 1200 rpm for 25 min, dried at 70℃ for 12 h, to obtain mixture particles, and the mixture particles are sent into a double screw extruder for extrusion to obtain the asphalt modifier.

[0075] Comparative Example 3

[0076] The difference between Example 1 is that the fiber is not modified, and the rest is consistent with Example 1.

[0077] That is, an asphalt modifier of the present comparative example, which comprises the following raw materials by weight: 13 g of modified sodium alginate-chitosan composite, 6 g of basalt fiber, 2 g of polyvinyl alcohol-poly (methyl methacrylate) copolymer and 2 g of styrene-maleic anhydride copolymer.

[0078] The preparation method of the above-mentioned modified sodium alginate-chitosan composite comprises:

[0079] (1) Chitosan is added to a 35wt% sodium hydroxide-methanol-DMF solution (volume ratio of methanol: DMF = 1:2) with a solid-liquid ratio of 1:8 g / mL, then (3-mercaptopropyl) trimethoxysilane is added, the mass ratio of (3-mercaptopropyl) trimethoxysilane to chitosan is 0.15:1, after mixing uniformly, hydrothermal reaction is carried out in a reaction kettle at 170℃ for 8h, cooling, deionized water washing, drying, to obtain an intermediate product;

[0080] (2) The intermediate product, polyvinyl alcohol and sodium alginate with a mass ratio of 1:6:1.5 are added to water, the solid-liquid ratio of the intermediate product to water is 1:15 g / mL, ultrasonic treatment is carried out at 35 kHz and 60℃ for 2h, 5wt% calcium chloride solution with a volume of 0.4 times that of water is added for crosslinking, then deionized water washing, vacuum freeze drying, to obtain the modified sodium alginate-chitosan composite.

[0081] The preparation method of an asphalt modifier of the present comparative example, the specific steps comprising:

[0082] The basalt fiber, the modified sodium alginate-chitosan composite, the polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer are added to water, the amount of water added is 4 times the total weight of the basalt fiber, the modified sodium alginate-chitosan composite, the polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer, mixed at 1200 rpm for 25 min, dried at 70℃ for 12h, to obtain the mixture particles, the mixture particles are sent into a twin-screw extruder for extrusion, to obtain the asphalt modifier.

[0083] Comparative Example 4

[0084] The difference between Example 1 is that the polyvinyl alcohol-poly (methyl methacrylate) copolymer is absent, and the rest is consistent with Example 1.

[0085] That is, an asphalt modifier of the present comparative example, which comprises the following raw materials by weight: 13 g of modified sodium alginate-chitosan composite, 6 g of modified fiber and 2 g of styrene-maleic anhydride copolymer.

[0086] The preparation method of the modified sodium alginate-chitosan composite includes:

[0087] (1) Chitosan is added into a 35wt% sodium hydroxide-methanol-DMF solution (volume ratio of methanol: DMF = 1:2) with a solid-liquid ratio of 1:8 g / mL, followed by the addition of (3-mercaptopropyl) trimethoxysilane, and the mass ratio of (3-mercaptopropyl) trimethoxysilane to chitosan is 0.15:1. After uniform mixing, hydrothermal reaction is performed in a reaction kettle at 170°C for 8h, and then cooling, deionized water washing, and drying are performed to obtain an intermediate product;

[0088] (2) The intermediate product, polyvinyl alcohol, and sodium alginate with a mass ratio of 1:6:1.5 are added into water, and the solid-liquid ratio of the intermediate product to water is 1:15 g / mL. Ultrasonic treatment is performed at 35 kHz and 60°C for 2h, and then a 5wt% calcium chloride solution with a volume of 0.4 times that of water is added for crosslinking. Subsequently, deionized water washing and vacuum freeze drying are performed to obtain the modified sodium alginate-chitosan composite.

[0089] The preparation method of the modified fiber includes mixing basalt fiber and 1-octyl-3-methylimidazolium hexafluorophosphate ionic liquid with a mass ratio of 6:1, and then treating in a plasma device. Specifically, the treatment is performed at 80W and 25 kHz for 25 min to obtain the modified fiber.

[0090] The preparation method of the asphalt modifier of the present comparative example includes the following specific steps:

[0091] The modified fiber, the modified sodium alginate-chitosan composite, and the styrene-maleic anhydride copolymer are added into water, and the amount of water added is 4 times the total weight of the modified fiber, the modified sodium alginate-chitosan composite, and the styrene-maleic anhydride copolymer. Mixing is performed at 1200 rpm for 25 min, and then drying is performed at 70°C for 12h to obtain mixture particles. The mixture particles are sent into a twin-screw extruder for extrusion to obtain the asphalt modifier.

[0092] Comparative Example 5

[0093] The difference between the present comparative example and Example 1 is that the styrene-maleic anhydride copolymer is absent, and the other conditions are the same as those of Example 1.

[0094] That is, the asphalt modifier of the present comparative example includes the following raw materials according to weight parts: 13g of the modified sodium alginate-chitosan composite, 6g of the modified fiber, and 2g of the polyvinyl alcohol-poly(methyl methacrylate) copolymer.

[0095] The preparation method of the modified sodium alginate-chitosan composite includes:

[0096] (1) According to the solid-liquid ratio of 1:8 g / mL, chitosan is added into 35 wt% sodium hydroxide-methanol-DMF solution (volume ratio of methanol: DMF = 1:2) and stirred, then (3-mercaptopropyl) trimethoxysilane is added, the mass ratio of (3-mercaptopropyl) trimethoxysilane to chitosan is 0.15:1, after mixing uniformly, hydrothermal reaction is carried out in a reaction kettle at 170℃ for 8h, cooling, deionized water washing, drying, to obtain an intermediate product;

[0097] (2) The intermediate product, polyvinyl alcohol and sodium alginate with a mass ratio of 1:6:1.5 are added into water, the solid-liquid ratio of the intermediate product to water is 1:15 g / mL, ultrasonic treatment is carried out at 35 kHz and 60℃ for 2h, 5 wt% calcium chloride solution with a volume of 0.4 times of water is added for crosslinking, then deionized water washing is carried out, vacuum freeze drying is carried out, to obtain a modified sodium alginate-chitosan composite.

[0098] The preparation method of the modified fiber comprises: mixing basalt fibers and 1-octyl-3-methylimidazolium hexafluorophosphate ionic liquid with a mass ratio of 6:1, and treating in a plasma device, specifically: treating at 80W and 25 kHz for 25 min, to obtain the modified fiber.

[0099] The preparation method of the asphalt modifier of the present comparative example comprises the following specific steps:

[0100] The modified fiber, the modified sodium alginate-chitosan composite and the polyvinyl alcohol-poly(methyl methacrylate) copolymer are added into water, the amount of water added is 4 times the total weight of the modified fiber, the modified sodium alginate-chitosan composite and the polyvinyl alcohol-poly(methyl methacrylate) copolymer, mixing at 1200 rpm for 25 min, drying at 70℃ for 12h, to obtain the mixture particles, the mixture particles are sent into a twin-screw extruder for extrusion, to obtain the asphalt modifier.

[0101] Test Example 1

[0102] 70# base asphalt is added into a mixing container and preheated to 150℃, the asphalt modifiers prepared in Examples 1-3 and Comparative Examples 1-5 are added into the 70# base asphalt according to a mass percentage of 5%, and sheared at 3000 rpm for 40 min, to obtain modified asphalt materials.

[0103] The softening point, 5℃ ductility, 25℃ penetration, 60℃ dynamic viscosity of the samples are tested according to the methods T0606-2011, T0605-2011 and T0604-2011, T0620-2000 in the “Highway Engineering Asphalt and Asphalt Mixture Test Regulations” (JTGE20-2011), and the results are shown in Table 1.

[0104] Table 1

[0105]

[0106] As shown in Table 1, the asphalt modifier prepared by the embodiments 1-3 of the present application is added into the asphalt, which improves the high-temperature performance and low-temperature performance of the asphalt, significantly improves the stability, and has good mechanical properties and road performance.

[0107] Test Example 2

[0108] The modified asphalt material in the test example 1 is used to prepare asphalt mixtures.

[0109] Specific method: the modified asphalt is heated to 60℃, the coarse aggregate, fine aggregate and mineral powder are mixed uniformly and heated to 175℃, and the two are mixed and stirred for 40s to obtain the asphalt mixture, and the mixing ratio is shown in Table 2.

[0110] The performance of each asphalt mixture is tested, and the results are shown in Table 3.

[0111] Table 2

[0112]

[0113] Table 3

[0114]

[0115] As shown in Table 3, the asphalt mixtures obtained by using the asphalt modifier prepared by the embodiments 1-3 of the present application have significantly increased dynamic stability, freeze-thaw splitting strength ratio and residual stability, which indicates that the overall performance of the asphalt mixture can be significantly improved, and has good mechanical properties and road performance.

[0116] The above only describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A bitumen modifier, characterized in that, According to parts by weight, the following raw materials are included: 10-15 parts of modified sodium alginate-chitosan compound, 5-8 parts of modified fiber, 1-3 parts of polyvinyl alcohol-poly (methyl methacrylate) copolymer and 1-3 parts of styrene-maleic anhydride copolymer; The preparation method of the modified sodium alginate-chitosan compound comprises: (1) adding chitosan into an alkaline methanol-DMF solution, mixing (3-mercaptopropyl) trimethoxysilane uniformly, carrying out hydrothermal reaction, cooling, washing and drying to obtain an intermediate product; (2) adding the intermediate product, polyvinyl alcohol and sodium alginate into water, carrying out ultrasonic treatment, adding calcium chloride solution for crosslinking, washing for several times and then vacuum freeze-drying to obtain the modified sodium alginate-chitosan compound; The preparation method of the modified fiber comprises: mixing basalt fiber with ionic liquid and then carrying out plasma treatment to obtain the modified fiber.

2. An asphalt modifier as claimed in claim 1, characterised in that, In step (1) of the preparation method of the modified sodium alginate-chitosan compound, the solid-liquid ratio of chitosan to the alkaline methanol-DMF solution is 1:6-10 g / mL; The alkaline methanol-DMF solution is sodium hydroxide-methanol-DMF solution with a concentration of 30-40 wt%, wherein the volume ratio of methanol to DMF is 1:1-3; The addition amount of (3-mercaptopropyl) trimethoxysilane is 0.1-0.2 times the weight of chitosan; The hydrothermal reaction is carried out at 160-180℃ for 6-10 h.

3. The asphalt modifier of claim 1, wherein, In step (2) of the preparation method of the modified sodium alginate-chitosan compound, the mass ratio of the intermediate product, polyvinyl alcohol and sodium alginate is 1:5-7:1-2; and the solid-liquid ratio of the intermediate product to water is 1:10-20 g / mL; The ultrasonic treatment is carried out at 30-40 kHz and 50-70℃ for 2-3 h; The concentration of the calcium chloride solution is 2-5 wt%, and the addition amount is 0.3-0.5 times the volume of water.

4. The asphalt modifier of claim 1, wherein, In the preparation method of the modified fiber, the ionic liquid is 1-octyl-3-methyl imidazole hexafluorophosphate ionic liquid; and the mass ratio of basalt fiber to ionic liquid is 5-7:1; The plasma treatment is carried out at 60-100 W and 20-30 kHz for 20-30 min.

5. A process for the preparation of a bitumen modifier according to any one of claims 1 to 4, characterized in that, The specific steps comprise: The modified fiber, the modified sodium alginate-chitosan compound, the polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer are added into water for mixing, drying is carried out to obtain mixture particles, and the mixture particles are sent into a double screw extruder for extrusion to obtain an asphalt modifier.

6. A process for preparing an asphalt modifier as claimed in claim 5, characterized in that, The addition amount of water is 3-5 times the total weight of the modified fiber, the modified sodium alginate-chitosan compound, the polyvinyl alcohol-poly (methyl methacrylate) copolymer and the styrene-maleic anhydride copolymer.

7. The use of the asphalt modifier according to any one of claims 1-4 in asphalt.

8. Use according to claim 7, wherein the compound is ###0002### The asphalt modifier is added into asphalt at a mass percentage of 3-6%.

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