A modified asphalt material and a method for producing the same

Abstract

This invention discloses a modified asphalt material, composed of mineral aggregates and a composite modified asphalt binder. The composite modified asphalt binder comprises the following components by weight: 100 parts petroleum asphalt, 3-6 parts styrene-based thermoplastic elastomer, 5-15 parts compounded epoxy resin, 4-12 parts compounded curing agent, 0.5-1.5 parts polyphosphoric acid, 2-8 parts modified polyvinyl alcohol fiber, 5-10 parts diatomaceous earth, and 0.1-1 parts anti-aging agent. This invention also discloses a method for preparing this modified asphalt material. The modified asphalt material provided by this invention utilizes hydrogen and chemical bonds between the various raw materials to form a multi-network structure, comprising the network structures of the compounded epoxy resin and compounded curing agent, the modified polyvinyl alcohol fiber, and the epoxy-oxidized styrene-based thermoplastic elastomer, thereby synergistically improving the durability of the asphalt material.

Description

Technical Field

[0001] This invention belongs to the field of road materials technology, specifically relating to a modified asphalt material and its preparation method. Background Technology

[0002] Transportation is a crucial factor constraining national economic development. With the rapid development of my country's national economy, road transportation has also developed rapidly. Previously, the main material for paving roads in my country was ordinary asphalt, which suffers from drawbacks such as low-temperature brittleness, high-temperature flow, poor adaptability to strain values, and poor fatigue resistance. Due to the long-term exposure of roads to water and moisture in the air, the asphalt decomposes and loses its binding force to sand and aggregates, resulting in a short road surface service life.

[0003] Currently, most highways abroad use modified asphalt as paving material. This modified asphalt possesses excellent durability, abrasion resistance, does not soften at high temperatures, and exhibits good low-temperature crack resistance, significantly extending the service life of the road surface. While some high-grade highways in China also use modified asphalt as paving material, they primarily rely on imported modified asphalt.

[0004] To improve the performance and durability of asphalt pavements, my country has imposed strict requirements on raw materials such as asphalt and aggregates, as well as construction machinery and processes during the construction of high-grade highway asphalt pavements. Researchers have proposed using various methods and materials to modify asphalt to improve the durability of asphalt and its mixtures, achieving significant results. However, with the continuous increase in domestic traffic volume, the existing asphalt pavement defects are becoming increasingly severe, causing great damage to road traffic in my country; the durability of existing modified asphalt can no longer meet the requirements for asphalt pavement use. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the main objective of this invention is to provide a modified asphalt material that addresses the problems of insufficient durability and frequent early-stage defects in existing asphalt materials. This invention also discloses a method for preparing this high-durability asphalt.

[0006] The objective of this invention is achieved through the following technical solution: In a first aspect, a modified asphalt material is composed of mineral aggregates and a composite modified asphalt binder, characterized in that the composite modified asphalt binder comprises the following components by weight: 100 parts petroleum asphalt, 3-6 parts styrene-based thermoplastic elastomer, 5-15 parts compounded epoxy resin, 4-12 parts compounded curing agent, 0.5-1.5 parts polyphosphoric acid, 2-8 parts modified polyvinyl alcohol fiber, 5-10 parts diatomaceous earth, and 0.1-1 parts anti-aging agent.

[0007] In some specific embodiments, the petroleum asphalt is one of 70# petroleum asphalt, 90# petroleum asphalt, or a mixture thereof.

[0008] In some specific embodiments, the styrene-based thermoplastic elastomer is an epoxidized styrene-butadiene-styrene triblock copolymer, and the mass fraction of epoxy groups is 3-9%.

[0009] In some specific embodiments, the compounded epoxy resin is composed of bisphenol A type epoxy resin, bisphenol F type epoxy resin and 6350 flexible epoxy resin, and the mass ratio of the bisphenol A type epoxy resin, bisphenol F type epoxy resin and 6350 flexible epoxy resin is 30-50:30-50:10-30.

[0010] In some specific embodiments, the compound curing agent is composed of a long-chain aliphatic primary amine, nitrile rubber and polyamide, wherein the mass ratio of the long-chain aliphatic primary amine, nitrile rubber and polyamide is 70-100:15-25:15-25.

[0011] Furthermore, the carbon chain length of the long-chain aliphatic primary amine is in the range of C... 10 -C 18 Between these ranges, the amine value is 150-250 mgKOH / g; the amine value of nitrile rubber is 30-80 mgKOH / g; and the molecular weight of polyamide is 500-1000, with an amine value of 150-250 mgKOH / g.

[0012] In some specific embodiments, the modified polyvinyl alcohol fiber is obtained by the following method: a certain amount of polyvinyl alcohol fiber is added to a reaction vessel, then an alkaline solution is added, the pH value of the system is controlled to be 12-13, the mixture is stirred evenly, then epichlorohydrin is slowly added in proportion, the reaction is continuously stirred for 4-6 hours, and finally the mixture is filtered, washed and dried to obtain the modified polyvinyl alcohol fiber.

[0013] Furthermore, the polyvinyl alcohol fiber has a tensile strength ≥1000MPa, a tensile elongation ≥8%, and a length of 3-6mm; the polyphosphoric acid contains more than 85% of the effective component P2O5.

[0014] In some specific embodiments, the mineral material includes basalt aggregate and limestone powder, wherein the basalt aggregate includes fine aggregate of 0-2.36 mm and coarse aggregate of ≥2.36 mm; the mass ratio of coarse aggregate, fine aggregate and limestone powder is 60-75:10-20:5-10.

[0015] Furthermore, the diatomaceous earth has a mesh size of 500-1000 mesh and a diatom mass fraction of ≥98%.

[0016] Furthermore, the anti-aging agent is a complex of a UV absorber and a hindered amine light stabilizer in a mass ratio of 1:1; the UV absorber is at least one of UV531, UV24, UV284 or UV49; and the hindered amine light stabilizer is HS-944.

[0017] Secondly, a method for preparing the aforementioned modified asphalt material includes the following steps: (1) According to the formula requirements, heat the petroleum asphalt to 170-180℃, add styrene thermoplastic elastomer, shear for 60-90min, the shearing machine speed is 3000-4000r / min, then add polyphosphoric acid, diatomaceous earth and anti-aging agent in sequence, stir continuously for 30-60min, keep the temperature at 170-185℃, and make modified asphalt; (2) At 40-50℃, bisphenol A type epoxy resin, bisphenol F type epoxy resin and 6350 flexible epoxy resin are mixed according to the formula ratio and stirred for 3-10 minutes to prepare a compound epoxy resin. (3) Mix long-chain aliphatic primary amine, nitrile rubber and polyamide in proportion, stir for 3-10 min to prepare a compound curing agent; (4) At 40-50℃, mix the compounded epoxy resin, modified polyvinyl alcohol fiber and compounded curing agent, stir for 3-10 minutes to prepare epoxy resin binder; (5) Mix the modified asphalt prepared in step (1) at a temperature of 170-185℃ with the epoxy resin binder at a temperature of 40-50℃ in proportion, stir for 3-5 minutes to make a composite modified asphalt binder, and keep the temperature of the composite modified asphalt binder at 160-185℃. (6) Keep the mineral materials at a temperature of 170-190℃ for 5-8 hours and mix them evenly according to the proportion; then add the composite modified asphalt binder prepared in step (5) and the mixed mineral materials into the mixing pot, keep the mixing temperature at 160-190℃, and stir for 3-5 minutes to obtain the modified asphalt material.

[0018] Compared with the prior art, the present invention has at least the following advantages: 1) The modified asphalt material provided by this invention forms a network structure after the reaction of a compound epoxy resin and a compound curing agent, which restricts the free flow of the asphalt material. An epoxy styrene-butadiene-styrene triblock copolymer forms a network structure in the asphalt system, and its epoxy functional groups react with the compound curing agent to form a stable network structure. Modified polyvinyl alcohol fibers, uniformly dispersed in the asphalt, form a network structure, producing reinforcement and overlapping effects, further restricting the free flow of the asphalt. Furthermore, the modified polyvinyl alcohol fibers have a polyhydroxy structure, enabling them to form hydrogen bonds with epoxy functional groups, and the epoxy functional groups grafted onto the surface of the modified polyvinyl alcohol fibers form chemical bonds with the curing agent. In other words, hydrogen bonding and chemical bonding can form a multi-network structure from the network structures of the compound epoxy resin and compound curing agent in the system, the network structure of the modified polyvinyl alcohol fibers in the system, and the network structure of the styrene-based thermoplastic elastomer in the system, thereby synergistically improving the durability of the asphalt material. Simultaneously, polyphosphoric acid can undergo a chemical cross-linking reaction with the active groups in the asphalt, further stabilizing the multi-network structure and improving the durability of the asphalt material.

[0019] 2) The modified asphalt material preparation method provided by this invention uses readily available raw materials, has simple steps, convenient experimental parameter control, and strong portability, and can be widely used in road construction in my country. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0021] When a quantity, concentration, or other value or parameter is described as a range, preferred range, or preferred upper and lower limits, it should be understood that it is equivalent to specifically disclosing any range by combining any pair of upper or preferred values ​​with any lower or preferred values, regardless of whether the range is specifically disclosed. Unless otherwise stated, the numerical range values ​​listed herein include the endpoints of the range and all integers and fractions within that range.

[0022] Unless otherwise stated, all percentages, parts, ratios, etc. in this document are by weight.

[0023] The materials, methods, and embodiments described herein are exemplary and should not be construed as limiting unless otherwise stated.

[0024] Unless otherwise specified, all raw materials, production equipment, and testing equipment mentioned in this article can be purchased commercially.

[0025] In the following embodiments, the styrene-based thermoplastic elastomer is an epoxidized styrene-butadiene-styrene triblock copolymer, and its epoxy group mass fraction is 6%.

[0026] The carbon chain length of the long-chain aliphatic primary amine is C. 12- C 18 The amine value of the polyamide was 201 mg KOH / g, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; the amine value of the nitrile rubber was 46 mg KOH / g, purchased from Jiadida New Material Technology Co., Ltd.; and the molecular weight of the polyamide was 813, with an amine value of 195 mg KOH / g, purchased from Ruichi Chemical (Hubei) Co., Ltd.

[0027] The modified polyvinyl alcohol fiber was obtained by the following method: 100 parts of polyvinyl alcohol fiber were added to a reaction vessel, then an alkaline solution was added, the pH of the system was controlled at 12, and the mixture was stirred evenly. Then, 50 parts of epichlorohydrin were slowly added, and the reaction was continuously stirred for 6 hours. Finally, the mixture was filtered, washed, and dried to obtain the modified polyvinyl alcohol fiber. The polyvinyl alcohol fiber had a tensile strength ≥1000MPa, an elongation at break ≥8%, and a length of 3-6mm. It was purchased from Shandong Luxian Building Materials Technology Co., Ltd. The polyphosphoric acid contained >85% of the effective component P2O5 and was purchased from Jinan Huifengda Chemical Co., Ltd.

[0028] The mineral materials include basalt aggregate and limestone powder. The basalt aggregate includes fine aggregate of 0-2.36mm and coarse aggregate of ≥2.36mm, and was purchased from Sichuan Hengtong Basalt Mining Co., Ltd.

[0029] The diatomaceous earth has a mesh size of 750 and a diatom mass fraction of 99.1%, and was purchased from Shengzhou Huali Diatomaceous Earth Products Co., Ltd.

[0030] The anti-aging agent is a complex of a UV absorber and a hindered amine light stabilizer in a mass ratio of 1:1. The UV absorber is UV531, purchased from Shijiazhuang Dayuan Chemical Co., Ltd.; the hindered amine light stabilizer is HS-944, purchased from Shanghai Yuanye Biotechnology Co., Ltd.

[0031] Example 1

[0032] The durable asphalt material provided by this invention is obtained by the following preparation method: (1) Heat 70# petroleum asphalt to 175°C, add 3 parts of epoxidized styrene-butadiene-styrene triblock copolymer with a mass fraction of 4% of epoxy group to 100 parts of 70# petroleum asphalt, shear for 60 min, shearing machine speed is 3000 r / min, then add 5 parts of diatomaceous earth and 0.2 parts of anti-aging agent in sequence, and continue stirring for 35 min, keeping the temperature at 175°C to make modified asphalt; (2) At 40°C, bisphenol A type epoxy resin, bisphenol F type epoxy resin and 6350 flexible epoxy resin are mixed in a ratio of 30:30:10 and stirred for 5 minutes to prepare a compound epoxy resin.

[0033] (3) Mix long-chain aliphatic primary amine, nitrile rubber and polyamide in a ratio of 70:15:15, stir for 5 minutes to prepare a compound curing agent (wherein the carbon chain length of the long-chain aliphatic primary amine is within C). 10 -C 18 Between these values, the amine value is 175 mg KOH / g; the amine value of nitrile rubber is 40 mg KOH / g; and the molecular weight of polyamide is 650, with an amine value of 180 mg KOH / g. (4) At 40°C, mix 5 parts of compounded epoxy resin, 3 parts of modified polyvinyl alcohol fiber and 4 parts of compounded curing agent, stir for 5 minutes to prepare epoxy resin binder; (5) Mix the modified asphalt prepared in step (1) at 175°C with the epoxy resin binder at 40°C in proportion, stir for 3 minutes to make a composite modified asphalt binder, and keep the temperature at 175°C. (6) Heat the aggregate to 175°C and maintain it at that temperature for 5 hours. Mix the coarse aggregate, fine aggregate and limestone powder in a mass ratio of 60:10:5 to obtain the aggregate. Then add 94% of the composite modified asphalt binder and the mixed 6% aggregate into the mixing pot (the mass percentage of the composite modified asphalt binder to the aggregate is 100%), maintain the mixing temperature at 175°C and stir for 3 minutes to obtain the modified asphalt material.

[0034] Example 2

[0035] The durable asphalt material provided by this invention is obtained by the following preparation method: (1) Heat 90# petroleum asphalt to 170°C, add 4 parts of epoxidized styrene-butadiene-styrene triblock copolymer with an epoxy group mass fraction of 6% for 100 parts of 90# petroleum asphalt, shear for 70 min, shearing machine speed is 3500 r / min, then add 7 parts of diatomaceous earth and 0.3 parts of anti-aging agent in sequence, and continue stirring for 40 min, keeping the temperature at 170°C to make modified asphalt; (2) At 45°C, bisphenol A type epoxy resin, bisphenol F type epoxy resin and 6350 flexible epoxy resin are mixed in a ratio of 40:40:20 and stirred for 5 minutes to prepare a compound epoxy resin.

[0036] (3) Mix long-chain aliphatic primary amine, nitrile rubber and polyamide in a ratio of 80:20:20, stir for 5 minutes to prepare a compound curing agent (wherein the carbon chain length of the long-chain aliphatic primary amine is within C).10 -C 18 Between these values, the amine value is 210 mg KOH / g; the amine value of nitrile rubber is 50 mg KOH / g; and the molecular weight of polyamide is 700, with an amine value of 200 mg KOH / g. (4) At 45°C, mix 10 parts of compounded epoxy resin, 5 parts of modified polyvinyl alcohol fiber and 7 parts of compounded curing agent, stir for 5 minutes to prepare epoxy resin binder; (5) Mix the modified asphalt prepared in step (1) at 170°C with the epoxy resin binder at 45°C in proportion, stir for 5 minutes to make a composite modified asphalt binder, and keep the temperature at 170°C. (6) Heat the aggregate to 170°C and maintain it at that temperature for 5 hours. Mix the coarse aggregate, fine aggregate and limestone powder in a mass ratio of 65:15:7 to obtain the aggregate. Then add 94% of the composite modified asphalt binder and the mixed 6% aggregate into the mixing pot (the mass percentage of the composite modified asphalt binder to the aggregate is 100%), maintain the mixing temperature at 170°C and stir for 3 minutes to obtain the modified asphalt material.

[0037] Example 3

[0038] The durable asphalt material provided by this invention is obtained by the following preparation method: (1) Heat 70# petroleum asphalt and 90# petroleum asphalt in a mass ratio of 2:1 to 180°C. Add 5 parts of epoxidized styrene-butadiene-styrene triblock copolymer with an epoxy group mass fraction of 8% per 100 parts of 70# petroleum asphalt and 90# petroleum asphalt. Shear for 80 min at a shearing machine speed of 4000 r / min. Then add 9 parts of diatomaceous earth and 0.5 parts of anti-aging agent in sequence, and continue stirring for 50 min while maintaining the temperature at 180°C to prepare modified asphalt. (2) At 50°C, bisphenol A type epoxy resin, bisphenol F type epoxy resin and 6350 flexible epoxy resin are mixed in a ratio of 50:50:30 and stirred for 5 minutes to prepare a compound epoxy resin.

[0039] (3) Mix long-chain aliphatic primary amine, nitrile rubber and polyamide in a ratio of 90:25:25, stir for 5 minutes to prepare a compound curing agent (wherein the carbon chain length of the long-chain aliphatic primary amine is within C). 10 -C 18 Between these values, the amine value is 230 mg KOH / g; the amine value of nitrile rubber is 58 mg KOH / g; and the molecular weight of polyamide is 950, with an amine value of 225 mg KOH / g. (4) At 50°C, mix 14 parts of compounded epoxy resin, 7 parts of modified polyvinyl alcohol fiber and 8 parts of curing agent, stir for 5 minutes to prepare epoxy resin binder; (5) Mix the modified asphalt prepared in step (1) at 180°C with the epoxy resin binder at 50°C in proportion, stir for 5 minutes to make a composite modified asphalt binder, and keep the temperature at 180°C. (6) Heat the aggregate to 180°C and maintain it at that temperature for 6 hours. Mix the coarse aggregate, fine aggregate and limestone powder in a mass ratio of 75:18:9 to obtain the aggregate. Then add 94% of the composite modified asphalt binder and the mixed 6% aggregate into the mixing pot (the mass percentage of the composite modified asphalt binder to the aggregate is 100%), maintain the mixing temperature at 180°C and stir for 3 minutes to obtain the modified asphalt material.

[0040] Example 4

[0041] The durable asphalt material provided in this embodiment has the same component ratio as in Example 2, except that 0.8 parts by weight of polyphosphoric acid is added, and its preparation method is the same as in Example 2.

[0042] Comparative Example 1 The modified asphalt material provided in this comparative example has the same component ratio as that in Example 2, except that the modified polyvinyl alcohol fiber is replaced with polyvinyl alcohol fiber, and its preparation method is the same as that in Example 2.

[0043] Comparative Example 2 The durable asphalt material provided in this embodiment has the same component ratio as that in Example 2, except that the epoxidized styrene-butadiene-styrene triblock copolymer is replaced with styrene-butadiene-styrene triblock copolymer (without epoxy groups), and its preparation method is the same as that in Example 2.

[0044] Comparative Example 3 The modified asphalt material provided in this comparative example has the same component ratio as that in Example 2. The difference is that bisphenol A type epoxy resin and long-chain aliphatic primary amine are used to replace the compound epoxy resin and compound curing agent. The preparation method is the same as that in Example 2.

[0045] Comparative Example 4 The modified asphalt material provided in this comparative example has the same component ratio as that in Example 2, except that it does not contain compounded epoxy resin, compounded curing agent and epoxidized styrene-butadiene-styrene triblock copolymer, and its preparation method is the same as that in Example 2.

[0046] Comparative Example 5 The modified asphalt material provided in this comparative example has the same component ratio as that in Example 2, except that it does not contain compounded epoxy resin, compounded curing agent and modified polyvinyl alcohol fiber, and its preparation method is the same as that in Example 2.

[0047] Comparative Example 6 The modified asphalt material provided in this comparative example has the same component ratio as that in Example 2, except that it does not contain epoxidized styrene-butadiene-styrene triblock copolymer and modified polyvinyl alcohol fiber. Its preparation method is the same as that in Example 2.

[0048] Blank group The modified asphalt material provided in this comparative example has the same component ratio as that in Example 2, except that it does not contain compounded epoxy resin, compounded curing agent, epoxidized styrene-butadiene-styrene triblock copolymer and modified polyvinyl alcohol fiber. Its preparation method is the same as that in Example 2.

[0049] Performance testing: This application takes Examples 2 and 4 as examples, and tests the technical indicators of the modified asphalt materials prepared in Examples 2 and 4, as well as Comparative Examples 1-6 and the blank group, according to the specifications such as (JTG+E20-2011) "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering". Under the condition that other technical indicators (void ratio <4%, stability >15kN, dynamic stability at 60℃ >10000 cycles / mm, low-temperature failure strain at -10℃ >3000) all meet the usage requirements, the specific results of their durability indicators are shown in Table 1: Table 1. Durability Indicators of Modified Asphalt Materials Prepared in Each Example and Comparative Example

[0050] As shown in Table 1, the modified asphalt material provided in this application exhibits excellent water stability and fatigue resistance (better water stability and fatigue resistance indicate better durability). Data from Examples 2 and 4 show that the addition of polyphosphoric acid further enhances the durability of the modified asphalt material. Data from Examples 2 and 1 show that after modification with epichlorohydrin fibers, the residual stability and four-point bending fatigue count of the modified asphalt increased by 5.4% and 49.4%, respectively, indicating that the epoxy functional groups of the modified polyvinyl alcohol fibers form chemical bonds with the curing agent, further improving the durability of the modified asphalt material. Data from Examples 2 and 2 show that the epoxidized styrene-butadiene-styrene triblock... After replacing the styrene-butadiene-styrene triblock copolymer with the copolymer, the residual stability and four-point bending fatigue count of the modified asphalt increased by 4.7% and 36.9%, respectively. This indicates that the epoxy functional groups of the epoxidized styrene-butadiene-styrene triblock copolymer react with the curing agent, improving the durability of the modified asphalt material. Data from Example 2 and Comparative Example 3 show that after replacing the bisphenol A type epoxy resin and long-chain aliphatic primary amine with a compound epoxy resin and a compound curing agent, the residual stability and four-point bending fatigue count of the modified asphalt increased by 4.4% and 40%, respectively. The 0.2% increase indicates that the compounded epoxy resin and compounded curing agent can help improve the durability of modified asphalt materials. Data from Example 2 and Comparative Example 4 show that the residual stability and four-point bending fatigue count of the modified asphalt increased by 10.9% and 238.2%, respectively. Data from Example 2 and Comparative Example 5 show that the residual stability and four-point bending fatigue count of the modified asphalt increased by 9.4% and 219.4%, respectively. Data from Example 2 and Comparative Example 6 show that the residual stability and four-point bending fatigue count of the modified asphalt increased by 9.5%. The data from Example 2 and the blank group show that the residual stability and four-point bending fatigue number of the modified asphalt increased by 12.1% and 400%, respectively. This indicates that under the synergistic effect of the compounded epoxy resin and compounded curing agent, epoxidized styrene-butadiene-styrene triblock copolymer and modified polyvinyl alcohol fiber, the modified asphalt material provided in this application has significantly improved its residual stability and four-point bending fatigue number while ensuring that other performance parameters meet the requirements. This greatly improves the durability of the material and can significantly extend the service life of the pavement.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A modified asphalt material, composed of mineral aggregates and composite modified asphalt binder, characterized in that, The composite modified asphalt binder comprises the following components by weight: 100 parts petroleum asphalt, 3-6 parts styrene-based thermoplastic elastomer, 5-15 parts compounded epoxy resin, 4-12 parts compounded curing agent, 0.5-1.5 parts polyphosphoric acid, 2-8 parts modified polyvinyl alcohol fiber, 5-10 parts diatomaceous earth, and 0.1-1 parts anti-aging agent. The compound epoxy resin is composed of bisphenol A type epoxy resin, bisphenol F type epoxy resin and 6350 flexible epoxy resin, and the mass ratio of bisphenol A type epoxy resin, bisphenol F type epoxy resin and 6350 flexible epoxy resin is 30-50:30-50:10-30. The compound curing agent is composed of long-chain aliphatic primary amine, nitrile rubber and polyamide, and the mass ratio of the long-chain aliphatic primary amine, nitrile rubber and polyamide is 70-100:15-25:15-25; The styrene-based thermoplastic elastomer is an epoxidized styrene-butadiene-styrene triblock copolymer, and the mass fraction of epoxy groups is 3-9%; the carbon chain length of the long-chain aliphatic primary amine is within C... 10 -C 18 Between these ranges, the amine value is 150-250 mgKOH / g; the amine value of nitrile rubber is 30-80 mgKOH / g; and the molecular weight of polyamide is 500-1000, with an amine value of 150-250 mgKOH / g. The modified polyvinyl alcohol fiber is obtained by the following method: a certain amount of polyvinyl alcohol fiber is added to a reaction vessel, then an alkaline solution is added, the pH value of the system is controlled to be 12-13, the mixture is stirred evenly, epichlorohydrin is slowly added in proportion, the reaction is continuously stirred for 4-6 hours, and finally the mixture is filtered, washed and dried.

2. The modified bitumen material according to claim 1, characterized in that, The petroleum asphalt is one of 70# petroleum asphalt, 90# petroleum asphalt, or a mixture thereof.

3. The modified bitumen material according to claim 2, characterized in that, The polyvinyl alcohol fiber has a breaking strength ≥1000MPa, a breaking elongation ≥8%, and a length of 3-6mm; the polyphosphoric acid contains more than 85% of the effective component P2O5.

4. The modified bitumen material according to claim 1, characterized in that, The mineral materials include basalt aggregate and limestone powder. The basalt aggregate includes fine aggregate of 0-2.36mm and coarse aggregate of ≥2.36mm. The mass ratio of coarse aggregate, fine aggregate and limestone powder is 60-75:10-20:5-10.

5. A method for preparing a modified asphalt material according to any one of claims 1-4, characterized in that, Includes the following steps: (1) According to the formula requirements, heat the petroleum asphalt to 170-180℃, add styrene thermoplastic elastomer, shear for 60-90min, the shearing machine speed is 3000-4000r / min, then add polyphosphoric acid, diatomaceous earth and anti-aging agent in sequence, stir continuously for 30-60min, keep the temperature at 170-185℃, and make modified asphalt; (2) At 40-50℃, bisphenol A type epoxy resin, bisphenol F type epoxy resin and 6350 flexible epoxy resin are mixed according to the formula ratio and stirred for 3-10 minutes to prepare a compound epoxy resin. (3) Mix long-chain aliphatic primary amine, nitrile rubber and polyamide in proportion, stir for 3-10 min to prepare a compound curing agent; (4) At 40-50℃, mix the compounded epoxy resin, modified polyvinyl alcohol fiber and compounded curing agent, stir for 3-10 minutes to prepare epoxy resin binder; (5) Mix the modified asphalt prepared in step (1) at a temperature of 170-185℃ with the epoxy resin binder at a temperature of 40-50℃ in proportion, stir for 3-5 minutes to make a composite modified asphalt binder, and keep the temperature of the composite modified asphalt binder at 160-185℃. (6) Keep the mineral materials at a temperature of 170-190℃ for 5-8 hours and mix them evenly according to the proportion; then add the composite modified asphalt binder prepared in step (5) and the mixed mineral materials into the mixing pot, keep the mixing temperature at 160-190℃, and stir for 3-5 minutes to obtain the modified asphalt material.

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