A high-toughness, high-modulus asphalt mixture and its preparation method

Abstract

This invention belongs to the field of road transportation engineering technology, and relates to a high-toughness, high-modulus asphalt mixture and its preparation method. By weight, the raw materials include aggregates, modified asphalt, a high-toughness modifier, a high-modulus modifier, and a fiber stabilizer. The aggregates include at least one of steel slag, basalt, and diabase. The high-toughness modifier includes at least one of polyethylene octene copolymer elastomer, methyl acrylate-butadiene-styrene copolymer, and ethylene propylene diene monomer (EPDM) rubber. The high-modulus modifier is composed of steel slag powder, a coupling agent, extractable oil, epoxy resin, and ethylene-vinyl acetate copolymer. The high-toughness, high-modulus asphalt mixture prepared by this invention exhibits excellent rutting resistance and anti-scattering properties, fully utilizing the high strength of steel slag coarse aggregate and the good filling properties of steel slag powder. Together with the organic modifier styrene-butadiene-styrene block copolymer, it enhances the cohesiveness and strength of the asphalt mixture.

Description

Technical Field

[0001] This invention belongs to the field of road transportation engineering technology, and more specifically relates to a high-toughness, high-modulus asphalt mixture and its preparation method. Background Technology

[0002] In recent years, due to the rapid advancement of urbanization, the number of motor vehicles and the volume of heavy traffic on roads have increased year by year, and urban traffic congestion has become increasingly prominent. Traditional asphalt mixture paving can no longer meet the requirements of urban road traffic for road surface load-bearing capacity and deformation resistance.

[0003] Bus Rapid Transit (BRT) systems effectively enhance public transport capacity and reduce traffic congestion, becoming a crucial solution for alleviating urban traffic problems. However, BRT utilizes enclosed stations and dedicated lanes, resulting in higher axle loads and wheel pressures compared to ordinary asphalt pavements. BRT bus tire pressures often reach 0.9 MPa, significantly higher than the 0.7 MPa of passenger cars. Furthermore, BRT vehicles exhibit a pronounced channelization effect. Due to the dedicated lanes, buses do not change lanes during operation, and the wheels are strictly loaded along their wheel tracks, leading to concentrated stress on the road surface. In contrast, the wheel load distribution on typical highways or urban expressways is normally distributed. This excessively concentrated loading has extremely adverse effects on rutting development and fatigue life. Near BRT stops, vehicles travel at slower speeds and experience more frequent starting and braking. For asphalt pavements, this slow loading is equivalent to high-temperature conditions, further contributing to permanent deformation. The braking and starting processes of vehicles exert horizontal shear forces on the road surface, also exacerbating rutting. Therefore, the traffic characteristics of BRT (Bus Rapid Transit) pose a severe challenge to pavement materials. Similarly, areas on urban roads, such as bus stops and intersections, also exhibit similar traffic characteristics to BRT. Experience shows that traditional asphalt pavement solutions cannot solve the problems present at BRT and bus stops, intersections, and other similar areas, often resulting in severe rutting, loosening, and other defects within a short period after the road opens to traffic.

[0004] To reduce road surface distress and improve the performance of asphalt pavement in special areas, the preparation of high-quality and efficient asphalt mixtures is crucial. The strength and abrasion resistance of aggregates in asphalt mixtures are essential for ensuring the load-bearing capacity and skid resistance of the pavement. Traditional SBS-modified asphalt or high-toughness modified asphalt mixtures can improve the bonding properties of conventional asphalt pavements, but these modified asphalt materials still cannot meet the driving characteristics of special traffic areas such as BRT. Therefore, to improve the overall performance of pavements, including rutting resistance and loosening resistance, it is necessary to research and develop asphalt mixtures with better viscosity and modulus. Summary of the Invention

[0005] The purpose of this invention is to provide a high-toughness, high-modulus asphalt mixture and its preparation method to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] One of the technical solutions of this invention is to provide a high-toughness, high-modulus asphalt mixture, wherein the raw materials, by weight, include:

[0008] The composition includes 91.4–94 parts aggregate, 5–7 parts modified asphalt, 0.4–0.8 parts high-toughness modifier, 0.3–0.4 parts high-modulus modifier, and 0.3–0.4 parts fiber stabilizer.

[0009] Furthermore, the aggregate includes at least one of steel slag, basalt, and diabase.

[0010] Preferably, the aggregate comprises steel slag and / or basalt.

[0011] Preferably, the aggregate is a mixture of steel slag and basalt, with a mixing mass ratio of 1:0.2 to 5.

[0012] Preferably, the mixing mass ratio is 0.4 to 0.6:1.

[0013] Preferably, the free calcium oxide content of the steel slag is not higher than 3.0%, and the polishing value is not lower than 45.

[0014] Basalt and diabase have superior strength and wear resistance compared to traditional limestone aggregates. However, as their mining volume decreases and prices soar, the cost of using basalt and diabase as aggregates continues to rise. Steel slag is a typical urban industrial solid waste, produced in enormous quantities, and its open-air stockpiling occupies a large amount of land. However, its mechanical properties are superior to conventional crushed stone, with high wear resistance, strong adhesion to asphalt, and a lower price. This invention selects stable steel slag as road aggregate, leveraging its advantages of high strength, good wear resistance, and low price to improve road surface performance. Simultaneously, it solves the land occupation and environmental pollution problems caused by open-air steel slag stockpiling.

[0015] Furthermore, the modified asphalt is prepared by grinding styrene-butadiene-styrene block copolymer and 70A base asphalt at 170-180°C, and its performance grade reaches PG 76-22.

[0016] Preferably, the amount of the styrene-butadiene-styrene block copolymer is 4% of the mass of the 70A base bitumen.

[0017] Preferably, the styrene-butadiene-styrene block copolymer is a linear styrene-butadiene-styrene block copolymer with a block ratio of 3:7.

[0018] Preferably, the modified asphalt prepared after grinding is kept at 160°C for later use.

[0019] Furthermore, the raw materials for the high-toughness modifier include at least one of polyethylene octene copolymer elastomer, methyl acrylate-butadiene-styrene copolymer, and ethylene propylene diene monomer (EPDM) rubber.

[0020] Preferably, the mass percentage of octene in the polyethylene octene copolymer elastomer is 20% to 30%.

[0021] Preferably, the preparation method of the high-toughness modifier includes: swelling the raw material of the high-toughness modifier in extracted oil for not less than 12 hours, and then extruding it to obtain the high-toughness modifier.

[0022] Preferably, in the preparation method of the high-toughness modifier, the amount of extracted oil is 1% to 20% of the mass of the high-toughness modifier.

[0023] Preferably, in the preparation method of the high-toughness modifier, the amount of extracted oil is 5-10% of the mass of the high-toughness modifier.

[0024] Preferably, when the raw materials of the high-toughness modifier are polyethylene octene copolymer elastomer, methyl acrylate-butadiene-styrene copolymer and ethylene propylene diene monomer rubber, their mass ratio is 10:0.1 to 10:2 to 15;

[0025] When the raw materials of the high-toughness modifier are polyethylene octene copolymer elastomer and methyl acrylate-butadiene-styrene copolymer, their mass ratio is 10:0.1 to 10;

[0026] When the raw materials of the high-toughness modifier are methyl acrylate-butadiene-styrene copolymer and ethylene propylene diene monomer (EPDM) rubber, the mass ratio is 0.1-10:2-15;

[0027] When the raw materials of the high-toughness modifier are polyethylene octene copolymer elastomer and ethylene propylene diene monomer (EPDM) rubber, their mass ratio is 10:2 to 15.

[0028] Furthermore, the raw materials for the high modulus modifier include steel slag powder, coupling agent, extracted oil, epoxy resin and ethylene-vinyl acetate copolymer, with a mass ratio of 0.1-1:0.01-0.5:0.1-0.3:0.2-3:0-3.

[0029] Preferably, the preparation method of the high modulus modifier includes stirring and premixing the raw materials of the high modulus modifier at 150-160°C, and then extruding them.

[0030] Preferably, the free calcium oxide content of the steel slag powder is not higher than 3.0%, the polishing value is not lower than 45, and the particle size is not higher than 400 mesh.

[0031] Preferably, the coupling agent is a silane coupling agent KH550 or KH560.

[0032] Preferably, the epoxy resin is E51 epoxy resin.

[0033] Furthermore, the preparation method of the high-toughness modifier and the extracted oil in the high-modulus modifier are Iranian extracted oil or reduced-temperature residue oil, with an aromatic content of not less than 40%.

[0034] Furthermore, the fiber stabilizer includes at least one of lignin fiber, polyester fiber, and glass fiber.

[0035] The second technical solution of the present invention provides a method for preparing the above-mentioned high-toughness and high-modulus asphalt mixture, comprising the following steps:

[0036] The aggregate and modified asphalt are mixed in a premix to obtain a premixed material;

[0037] The high-toughness, high-modulus modifier and fiber stabilizer are added to the premix and mixed to obtain the high-toughness, high-modulus asphalt mixture.

[0038] Furthermore, the temperature of the premixing is 170–180°C, and the time is 1–3 minutes.

[0039] Furthermore, the mixing temperature is 180–190°C, and the mixing time is 1–2 minutes.

[0040] Furthermore, the aggregate needs to be heated to a temperature of not less than 200°C before being mixed with the modified asphalt premix.

[0041] Furthermore, the discharge temperature of the high-toughness, high-modulus asphalt mixture is 185–200°C.

[0042] The third technical solution of the present invention provides an application of the above-mentioned high-toughness and high-modulus asphalt mixture in the field of road transportation engineering.

[0043] As can be seen from the above technical solution, compared with the existing technology, it has the following beneficial effects:

[0044] This invention utilizes a composite of steel slag and basalt or diabase aggregates, modified asphalt, high-toughness modifier, and high-modulus modifier to prepare a high-toughness, high-modulus asphalt mixture with anti-rutting and anti-scattering properties. It fully leverages the high strength and good filling properties of steel slag coarse aggregate and steel slag powder, and together with the organic modifier styrene-butadiene-styrene block copolymer, enhances the cohesiveness and strength of the asphalt mixture, forming a high-strength, stable asphalt pavement paving mixture.

[0045] The high-toughness, high-modulus asphalt mixture prepared by this invention has good inter-material bonding performance and high strength, which can effectively solve the road surface damage caused by stress impact from heavy traffic and BRT station vehicle channelization, frequent starting and braking.

[0046] The high-toughness, high-modulus asphalt mixture provided by this invention makes extensive use of solid waste such as steel slag, steel slag powder, waste rubber powder, and waste plastics. This not only improves the material properties of the asphalt mixture but also reduces urban industrial solid waste pollution, alleviating the problems of lack of high-quality materials for road construction and difficulties in the treatment of industrial solid waste, thus achieving a win-win situation for both economic and environmental benefits. Detailed Implementation

[0047] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] The steel slag powder and the free calcium oxide content in the steel slag used in the embodiments and comparative examples of the present invention are 1.4% and the polishing value is 53; the octene content in the polyethylene octene copolymer elastomer is between 20% and 30%.

[0049] Example 1

[0050] Preparation of high-toughness, high-modulus asphalt mixtures:

[0051] S1. Steel slag and basalt are mixed at a mass ratio of 4:6 and heated to 210℃ to obtain aggregate, which is then set aside.

[0052] S2. The linear styrene-butadiene-styrene block copolymer (block ratio of 3:7) is mixed with 70A base asphalt at a mass ratio of 4%. The mixture is then sheared and ground at 4000 r / min for 45 min at 180℃ and stirred for 2 h to obtain modified asphalt with a performance grade of PG 76-22. The modified asphalt is then kept at 160℃ for later use.

[0053] S3. Mix polyethylene octene copolymer elastomer and methyl acrylate-butadiene-styrene copolymer in a mass ratio of 1:1, add 10% of the total mass of the two copolymers of Iranian extracted oil (aromatic content 51%), mix and swell at room temperature for 18 hours, and then extrude through a twin-screw extruder to obtain a high-toughness modifier for later use.

[0054] S4. Mix 500-mesh steel slag powder, coupling agent (silane coupling agent KH550), Iranian extracted oil (aromatic content 51%), and epoxy resin (E51 epoxy resin) at a mass ratio of 1:0.5:0.2:2 at 175°C for 1.5 min. After uniform mixing, extrude the mixture through a twin-screw extruder to obtain a high-modulus additive for later use.

[0055] S5. Premix the aggregate at 210℃ and the modified asphalt at 160℃ at 175℃ for 2 minutes to obtain a premix; add a high-toughness modifier, a high-modulus modifier and a fiber stabilizer to the premix and stir to obtain the high-toughness and high-modulus asphalt mixture. Stir and mix at 186℃ for 2 minutes and then discharge to obtain the high-toughness and high-modulus asphalt mixture.

[0056] The mass ratio of aggregate, modified asphalt, high-toughness modifier, high-modulus modifier and lignin fiber is 94.0:5.2:0.3:0.2:0.3; the final discharge temperature of the mixture is 185℃.

[0057] Example 2

[0058] Preparation of high-toughness, high-modulus asphalt mixtures:

[0059] S1. Steel slag and basalt are mixed at a mass ratio of 0.5:1 and heated to 220℃ to obtain aggregate for later use;

[0060] S2. The linear styrene-butadiene-styrene block copolymer (block ratio of 3:7) is mixed with 70A base asphalt at a mass ratio of 4%. The mixture is then sheared and ground at 4000 r / min for 45 min at 180℃ and stirred for 2 h to obtain modified asphalt with a performance grade of PG 76-22. The modified asphalt is then kept at 160℃ for later use.

[0061] S3. Mix polyethylene octene copolymer elastomer, methyl acrylate-butadiene-styrene copolymer and ethylene propylene diene monomer (EPDM) rubber in a mass ratio of 4:2:5. Add 5% of Iranian extracted oil (aromatic content 51%) of the total mass of the two copolymers and rubber. Mix and swell at room temperature for 12 hours. Extrude the mixture using a twin-screw extruder to obtain a high-toughness modifier for later use.

[0062] S4. 400-mesh steel slag powder, coupling agent (silane coupling agent KH560), Iranian extracted oil (aromatic content 51%), epoxy resin (E51 epoxy resin) and ethylene-vinyl acetate copolymer are mixed at 1:0.2:0.2:2:1.5 by mass at 160°C for 1.5 min. After uniform mixing, the mixture is extruded through a twin-screw extruder to obtain a high-modulus additive for later use.

[0063] S5. Premix the aggregate at 220℃ and the modified asphalt at 160℃ at 180℃ for 2 minutes to obtain a premix; add a high-toughness modifier, a high-modulus modifier and a fiber stabilizer to the premix and stir to obtain the high-toughness and high-modulus asphalt mixture. Stir and mix at 190℃ for 2 minutes and then discharge to obtain the high-toughness and high-modulus asphalt mixture.

[0064] The mass ratio of aggregate, modified asphalt, high-toughness modifier, high-modulus modifier and polyester fiber is 93.8:5.4:0.3:0.2:0.3; the final discharge temperature of the mixture is 188℃.

[0065] Example 3

[0066] Preparation of high-toughness, high-modulus asphalt mixtures:

[0067] S1. Steel slag and basalt are mixed at a mass ratio of 1:1 and heated to 210℃ to obtain aggregate, which is then set aside.

[0068] S2. The linear styrene-butadiene-styrene block copolymer (block ratio of 3:7) is mixed with 70A base asphalt at a mass ratio of 4%. The mixture is then sheared and ground at 4000 r / min for 45 min at 180℃ and stirred for 2 h to obtain modified asphalt with a performance grade of PG 76-22. The modified asphalt is then kept at 160℃ for later use.

[0069] S3. Mix polyethylene octene copolymer elastomer and ethylene propylene diene monomer (EPDM) rubber at a mass ratio of 1:1.5, add 20% of the total mass of the copolymer elastomer and rubber of Iranian extracted oil (aromatic content 51%), mix and swell at room temperature for 24 hours, and then extrude through a twin-screw extruder to obtain a high-toughness modifier for later use.

[0070] S4. 600-mesh steel slag powder, coupling agent (silane coupling agent KH550), Iranian extracted oil (aromatic content 51%), epoxy resin (E51 epoxy resin) and ethylene-vinyl acetate copolymer are mixed at 180°C for 1.5 min in a mass ratio of 1:0.5:0.8:1.3:2. After being mixed evenly, the mixture is extruded through a twin-screw extruder to obtain a high-modulus additive for later use.

[0071] S5. Premix the aggregate at 210℃ and the modified asphalt at 160℃ at 180℃ for 2 minutes to obtain a premix; add high-toughness modifier, high-modulus modifier and fiber stabilizer to the premix and stir to obtain the high-toughness and high-modulus asphalt mixture. After mixing at 190℃ for 1.5 minutes, discharge the material to obtain the high-toughness and high-modulus asphalt mixture.

[0072] The mass ratio of aggregate, modified asphalt, high-toughness modifier, high-modulus modifier and glass fiber is 93.9:5.2:0.4:0.2:0.3; the final discharge temperature of the mixture is 189℃.

[0073] Comparative Example 1

[0074] Preparation of modified asphalt mixtures:

[0075] S1. Basalt rock is selected as coarse aggregate and heated to 210℃ for later use;

[0076] S2. The linear styrene-butadiene-styrene block copolymer (block ratio of 3:7) is mixed with 70A base asphalt at a mass ratio of 4%. The mixture is then sheared and ground at 4000 r / min for 45 min at 180℃ and stirred for 2 h to obtain modified asphalt with a performance grade of PG 76-22. The modified asphalt is then kept at 160℃ for later use.

[0077] S3. Mix aggregates at 210℃, modified asphalt at 160℃, and lignin fibers at 180℃ for 2 minutes to obtain the modified asphalt mixture.

[0078] The mixture contains 5.5% PG 76-22 modified asphalt, 0.3% fiber by mass of asphalt mixture, and the remainder is aggregate. The final discharge temperature of the mixture is 178℃.

[0079] Comparative Example 2

[0080] Preparation of high-toughness modified asphalt mixture:

[0081] S1. Basalt stone is selected as coarse aggregate and heated to 210℃ for later use;

[0082] S2. Commercially available high-toughness modified asphalt (dynamic viscosity at 60℃ is 24780 Pa.s) is used as binder and heated to 160℃ for later use.

[0083] S3. Mix aggregates at 210℃, high-toughness modified asphalt at 160℃, and lignin fibers at 188℃ for 2-3 minutes to obtain high-toughness modified asphalt mixture.

[0084] The high-toughness modified asphalt content is 5.8%, the fiber content is 0.3% of the asphalt mixture mass, and the remainder is aggregate. The final discharge temperature of the mixture is 184℃.

[0085] Comparative Example 3

[0086] Compared to Example 2, the only difference is that no high-toughness modifier was added. The preparation steps of the asphalt mixture are as follows:

[0087] S1. Steel slag and basalt are mixed at a mass ratio of 0.5:1 and heated to 220℃ to obtain aggregate for later use;

[0088] S2. The linear styrene-butadiene-styrene block copolymer (block ratio of 3:7) and 70A base asphalt are mixed at a mass ratio of 4%. The mixture is then sheared and ground at 4000 r / min for 45 min at 180℃ and stirred for 2 h to obtain modified asphalt with a performance grade of PG 76-22. The modified asphalt is then kept at 160℃ for later use.

[0089] S3. 400-mesh steel slag powder, coupling agent (silane coupling agent KH550), Iranian extracted oil (aromatic content 51%), epoxy resin (E51 epoxy resin) and ethylene-vinyl acetate copolymer are mixed at 1:0.2:0.2:2:1.5 by mass at 160°C for 1.5 min. After uniform mixing, the mixture is extruded through a twin-screw extruder to obtain a high-modulus additive for later use.

[0090] S4. Premix aggregate at 220℃ and modified asphalt at 160℃ at 180℃ for 2 minutes to obtain premix; add high modulus modifier and fiber stabilizer to premix, stir and mix at 190℃ for 2 minutes, and then discharge to obtain asphalt mixture.

[0091] The mass ratio of aggregate, modified asphalt, high modulus modifier and polyester fiber is 94.1:5.4:0.2:0.3; the final discharge temperature of the mixture is 188℃.

[0092] Comparative Example 4

[0093] Compared to Example 2, the only difference is that no high-modulus modifier was added. The preparation steps of the asphalt mixture are as follows:

[0094] S1. Steel slag and basalt are mixed at a mass ratio of 0.5:1 and heated to 220℃ to obtain aggregate for later use;

[0095] S2. The linear styrene-butadiene-styrene block copolymer (block ratio of 3:7) is mixed with 70A base asphalt at a mass ratio of 4%. The mixture is then sheared and ground at 4000 r / min for 45 min at 180℃ and stirred for 2 h to obtain modified asphalt with a performance grade of PG 76-22. The modified asphalt is then kept at 160℃ for later use.

[0096] S3. Mix polyethylene octene copolymer elastomer, methyl acrylate-butadiene-styrene copolymer and ethylene propylene diene monomer (EPDM) rubber in a mass ratio of 4:2:5. Add 5% of Iranian extracted oil (aromatic content 51%) of the total mass of the two copolymers and rubber. Mix and swell at room temperature for 12 hours. Extrude the mixture using a twin-screw extruder to obtain a high-toughness modifier for later use.

[0097] S4. Premix aggregate at 220℃ and modified asphalt at 160℃ at 180℃ for 2 minutes to obtain premix; add high-toughness modifier and fiber stabilizer to premix, stir and mix at 190℃ for 2 minutes, and then discharge to obtain asphalt mixture.

[0098] The mass ratio of aggregate, modified asphalt, high-toughness modifier and polyester fiber is 93.8:5.4:0.3:0.3; the final discharge temperature of the mixture is 188℃.

[0099] Comparative Example 5

[0100] Compared to Example 2, the only difference is that no high-modulus modifier or high-toughness modifier was added. The preparation steps of the asphalt mixture are as follows:

[0101] S1. Steel slag and basalt are mixed at a mass ratio of 0.5:1 and heated to 220℃ to obtain aggregate for later use;

[0102] S2. The linear styrene-butadiene-styrene block copolymer (block ratio of 3:7) is mixed with 70A base asphalt at a mass ratio of 4%. The mixture is then sheared and ground at 4000 r / min for 45 min at 180℃ and stirred for 2 h to obtain modified asphalt with a performance grade of PG 76-22. The modified asphalt is then kept at 160℃ for later use.

[0103] S3. Premix aggregate at 220℃ and modified asphalt at 160℃ at 180℃ for 2 minutes to obtain premix; add fiber stabilizer to premix, stir and mix at 190℃ for 2 minutes, and then discharge to obtain asphalt mixture.

[0104] The mass ratio of aggregate, modified asphalt, and polyester fiber is 94.3:5.4:0.3; the final discharge temperature of the mixture is 188℃.

[0105] Test case

[0106] The asphalt mixtures prepared in Examples 1-3 and Comparative Examples 1-5 were immediately molded into Marshall specimens after discharge, and their performance was tested. The test results are shown in Table 1.

[0107] The Marshall stability test method, dynamic stability test, Hamburg rut depth test and gyroscopic rut depth test method shall be performed in accordance with the "Test Procedures for Highway Engineering and Asphalt Mixtures" JTG E20.

[0108] Table 1. Performance Comparison of Embodiments and Comparative Examples of the Invention

[0109]

[0110]

[0111] As can be seen from the test data in Table 1, the high-toughness and high-modulus asphalt mixtures prepared in Examples 1-3 of the present invention exhibit good Marshall stability and high-temperature dynamic stability, with performance far exceeding that of traditional asphalt mixtures (Comparative Examples 1 and 2) and existing specifications. After the Hamburg rutting test and the gyratory rutting test, the specimens of Comparative Examples 1-2 showed a large rutting depth, while the specimens of Examples 1-3 of the present invention showed excellent performance, possessing excellent resistance to kneading and loosening and rutting resistance.

[0112] A comparison of the data from Example 2 and Comparative Examples 3-5 shows that the synergistic effect of adding both high-toughness modifier and high-modulus modifier can significantly improve Marshall stability and high-temperature dynamic stability.

[0113] The high-toughness, high-modulus asphalt mixture designed using this invention exhibits excellent Marshall stability and high-temperature dynamic stability, far exceeding the performance of existing traditional asphalt mixtures and current specification requirements. In the Hamburg rutting test and the cyclone rutting test, the comparative specimens showed significant rutting depths, while the embodiments of this invention demonstrated superior performance, exhibiting excellent resistance to kneading and loosening, and excellent rutting resistance.

[0114] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0115] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-toughness, high-modulus asphalt mixture, characterized in that, By weight, the raw materials include: The mixture contains 91.4-94 parts aggregate, 5-7 parts modified asphalt, 0.4-0.8 parts high-toughness modifier, 0.3-0.4 parts high-modulus modifier, and 0.3-0.4 parts fiber stabilizer. The aggregates include steel slag and basalt, or steel slag and diabase; The modified asphalt was prepared by grinding styrene-butadiene-styrene block copolymer and 70A base asphalt at 170-180°C, achieving a performance grade of PG 76-22; the amount of styrene-butadiene-styrene block copolymer was 4% of the mass of the 70A base asphalt. The raw materials for the high-toughness modifier include at least two of the following: polyethylene octene copolymer elastomer, methyl acrylate-butadiene-styrene copolymer, and ethylene propylene diene monomer (EPDM) rubber. The raw materials for the high modulus modifier include steel slag powder, coupling agent, extracted oil, E51 epoxy resin and ethylene-vinyl acetate copolymer, with a mass ratio of 0.1~1:0.01~0.5:0.1~0.3:0.2~3:0~3; The fiber stabilizer includes at least one of lignin fiber, polyester fiber and glass fiber; The preparation steps of the high-toughness modifier include: swelling the raw material of the high-toughness modifier in extracted oil for no less than 12 hours, and then extruding it to obtain the high-toughness modifier; the amount of extracted oil used is 1% to 20% of the mass of the raw material of the high-toughness modifier; The preparation steps of the high modulus modifier include: stirring and premixing the raw materials of the high modulus modifier at 150~160℃, followed by extrusion and processing to obtain the high modulus modifier; When the raw materials of the high-toughness modifier are polyethylene octene copolymer elastomer, methyl acrylate-butadiene-styrene copolymer and ethylene propylene diene monomer rubber, their mass ratio is 10:0.1~10:2~15; When the raw materials of the high-toughness modifier are polyethylene octene copolymer elastomer and methyl acrylate-butadiene-styrene copolymer, their mass ratio is 10:0.1~10; When the raw materials of the high-toughness modifier are methyl acrylate-butadiene-styrene copolymer and ethylene propylene diene monomer (EPDM) rubber, the mass ratio is 0.1~10:2~15; When the raw materials of the high-toughness modifier are polyethylene octene copolymer elastomer and ethylene propylene diene monomer (EPDM) rubber, their mass ratio is 10:2~15.

2. The high-toughness, high-modulus asphalt mixture according to claim 1, characterized in that, The coupling agent includes silane coupling agent KH550 or silane coupling agent KH560.

3. The high-toughness, high-modulus asphalt mixture according to claim 1, characterized in that, The extracted oil is Iranian extracted oil or reduced-grade residue oil, with an aromatic content of not less than 40%.

4. A method for preparing high-toughness, high-modulus asphalt mixture as described in any one of claims 1 to 3, characterized in that the steps... include: The aggregate and modified asphalt are mixed in a premix to obtain a premixed material; The high-toughness, high-modulus modifier and fiber stabilizer are added to the premix and mixed to obtain the high-toughness, high-modulus asphalt mixture.

5. The preparation method according to claim 4, characterized in that, The premixing temperature is 170~180℃ and the time is 1~3 min; the stirring temperature is 180~190℃ and the time is 1~2 min.

6. The preparation method according to claim 4, characterized in that, The aggregates need to be heated to a temperature of not less than 200°C before being mixed with the modified asphalt premix; the discharge temperature of the high-toughness, high-modulus asphalt mixture is 185~200°C.

7. The application of the high-toughness, high-modulus asphalt mixture as described in any one of claims 1 to 3 in the field of road transportation engineering.

Images