A fatigue-resistant and durable asphalt concrete and its preparation method

Abstract

This application relates to the technical field of asphalt concrete, and in particular to a fatigue-resistant and durable asphalt concrete and its preparation method. The fatigue-resistant and durable asphalt concrete comprises the following raw materials in parts by weight: 90-99 parts of mixture, 1-10 parts of asphalt material, and 0.5-1.5 parts of modified composite material; the mixture comprises the following raw materials in parts by weight: 20-30 parts of basalt with a particle size of 10-15 mm, 25-35 parts of basalt with a particle size of 5-10 mm, 5-15 parts of basalt with a particle size of 3-5 mm, 25-37 parts of basalt with a particle size of 0.01-3 mm, and 1-5 parts of mineral powder. This application provides a fatigue-resistant and durable asphalt concrete and its preparation method. This material exhibits excellent fatigue resistance and durability. By optimizing the combination ratio of the mixture, asphalt material, and modified composite material, and adjusting the raw materials of the modified composite material, the fatigue resistance and durability of the asphalt concrete are significantly improved.

Description

Technical Field

[0001] This application relates to the technical field of asphalt concrete, and in particular to a fatigue-resistant and durable asphalt concrete and its preparation method. Background Technology

[0002] Asphalt concrete, as the most widely used pavement material in road engineering, is widely used in highways, urban arterial roads, rural roads, and various transportation hubs due to its good adhesion, driving comfort, convenient construction, and excellent noise reduction properties. Currently, the preparation technology of asphalt concrete has become increasingly sophisticated. It mainly uses asphalt as a binder, combined with coarse aggregate, fine aggregate, and mineral powder, and adds modifiers and anti-aging agents according to road requirements. By optimizing aggregate gradation and improving mixing, paving, and compaction processes, basic indicators such as pavement strength, resistance to high and low temperatures, and resistance to water damage are improved. It can basically meet the short-term service requirements under conventional traffic loads, providing important support for the development of the transportation industry.

[0003] With the continuous growth of traffic flow and the increasing proportion of heavy-duty and overloaded vehicles, coupled with the repeated effects of natural environmental factors such as diurnal temperature variations, freeze-thaw cycles, and rainwater erosion, asphalt concrete pavements are subjected to the dual effects of repeated loading and environmental erosion. Insufficient fatigue durability has become a core technical problem restricting their service life. Under long-term repeated loading, the binder of existing asphalt concrete is prone to aging and embrittlement. The molecular chain breaks, leading to a decline in bonding performance. Delamination between aggregates and asphalt is likely to occur, which initiates microcracks and gradually expands, causing fatigue diseases such as pavement cracking, loosening, and potholes. At the same time, existing modification technologies have limited improvement on the fatigue performance of asphalt. Some modifiers have poor compatibility with asphalt, easily leading to segregation and degradation. Furthermore, traditional gradation design cannot balance strength and fatigue toughness, resulting in a short fatigue life of the pavement during long-term service. This not only increases the frequency and cost of pavement maintenance but also affects the safety and smoothness of traffic flow, failing to meet the actual needs of long-term stable service of pavements in heavy traffic and complex environments.

[0004] Therefore, how to effectively develop an asphalt concrete with fatigue resistance and durability has become an urgent problem to be solved. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this application provides fatigue-resistant and durable asphalt concrete and its preparation method.

[0006] In a first aspect, this application provides a fatigue-resistant and durable asphalt concrete, employing the following technical solution: A fatigue-resistant and durable asphalt concrete comprises the following raw materials in parts by weight: 90-99 parts of mixture, 1-10 parts of asphalt material, and 0.5-1.5 parts of modified composite material; The mixture comprises the following raw materials in parts by weight: 20-30 parts of basalt with a particle size of 10-15 mm, 25-35 parts of basalt with a particle size of 5-10 mm, 5-15 parts of basalt with a particle size of 3-5 mm, 25-37 parts of basalt with a particle size of 0.01-3 mm, and 1-5 parts of mineral powder.

[0007] Preferably, the asphalt concrete comprises the following raw materials in parts by weight: 94-96 parts of mixture, 4-6 parts of asphalt material, and 0.5-1.5 parts of modified composite material.

[0008] The mixture comprises the following raw materials in parts by weight: 20-30 parts of basalt with a particle size of 10-15 mm, 25-35 parts of basalt with a particle size of 5-10 mm, 5-15 parts of basalt with a particle size of 3-5 mm, 25-37 parts of basalt with a particle size of 0.01-3 mm, and 1-5 parts of mineral powder.

[0009] Preferably, the asphalt material is SBS modified asphalt with a relative density of 1.025.

[0010] Preferably, the basalt with a particle size of 10-15 mm has an apparent relative density of 2.841 and a bulk relative density of 2.789.

[0011] Preferably, the basalt with a particle size of 5-10 mm has an apparent relative density of 2.823, a bulk relative density of 2.753, a crushing value of 13.4%, and a needle-like and flaky particle content of 8.7%.

[0012] Preferably, the basalt with a particle size of 3-5 mm has an apparent relative density of 2.809 and a bulk relative density of 2.738.

[0013] Preferably, the basalt with a particle size of 0.01-3 mm has an apparent relative density of 2.787, a bulk relative density of 2.687, a water absorption rate of 1.6, and a sand equivalent of 70%.

[0014] Preferably, the mineral powder has an apparent relative density of 2.691 and a hydrophilicity coefficient of 0.85.

[0015] By adopting the above technical solutions, this application has achieved significant improvements in fatigue resistance and durability: the tightly interlocked skeleton constructed by basalt effectively reduces stress concentration in asphalt under cyclic loading, and combined with the excellent viscoelastic recovery ability of SBS modified asphalt, the mixture can quickly release deformation energy under repeated tensile and compressive stresses; at the same time, the incorporated modified composite materials play a bridging and reinforcing role at the microscopic level, effectively inhibiting the initiation and propagation of microcracks, while the low hydrophilicity coefficient of mineral powder and basalt ensures high-strength adhesion of the asphalt film and prevents interface delamination caused by water intrusion; the synergistic effect of the above multiple mechanisms significantly delays the generation and penetration of fatigue cracks, enabling the pavement to maintain structural integrity after undergoing millions of load cycles, thereby improving the fatigue resistance and durability of asphalt concrete.

[0016] Preferably, the modified composite material comprises the following raw materials in parts by weight: 0.1-0.5 parts of nano-carbon spheres, 80-120 parts of ethanol (first part), 5-15 parts of tetrabutyl titanate, 20-30 parts of ethanol (second part), 5-15 parts of water (first part), 1-6 parts of lanthanum nitrate trihydrate, 2-7 parts of ferric nitrate nonahydrate, 1-6 parts of citric acid, 40-60 parts of water (second part), 1-5 parts of ethylene glycol, 1-5 parts of styrene-butadiene-styrene block copolymer, 0.5-1.5 parts of nano-silica, and 0.01-0.05 parts of coupling agent.

[0017] Preferably, the nanocarbon spheres comprise the following raw materials in parts by weight: 5-10 parts glucose and 30-50 parts water.

[0018] Preferably, the preparation method of the carbon nanospheres includes the following steps: mixing glucose and a third part of water, reacting at 160-180℃ for 8-12 hours, separating and drying to obtain carbon nanospheres.

[0019] Preferably, the preparation method of the modified composite material includes the following steps: mixing carbon nanospheres and a first portion of ethanol, adding tetrabutyl titanate, a second portion of ethanol, and a first portion of water, mixing, drying, and calcining to obtain product 1; Lanthanum nitrate trihydrate, ferric nitrate nonahydrate, citric acid, and a second portion of water were mixed, ethylene glycol was added and mixed, product 1 was added and mixed, then dried and calcined to obtain product 2. Product 2 and nano-silica were mixed, a coupling agent was added and mixed, and then styrene-butadiene-styrene block copolymer was added and mixed to obtain the modified composite material.

[0020] By adopting the above technical solution, this application uses carbon nanospheres, tetrabutyl titanate, lanthanum nitrate trihydrate, ferric nitrate nonahydrate, citric acid, and ethylene glycol as raw materials to prepare a hollow core-shell composite material (i.e., product 2). The hollow core-shell composite material (i.e., product 2) utilizes the excellent catalytic activity of lanthanum iron perovskite and the toughness of carbon nanospheres to form a highly efficient UV shielding and free radical scavenging system in asphalt concrete. This effectively inhibits the molecular chain breakage and aging hardening of asphalt binder under photothermal and oxygen environments, maintaining the material's flexibility from the root. The hollow core-shell structure possesses both rigid skeleton and flexible buffer properties, constructing a three-dimensional reinforcing network in the asphalt matrix: on the one hand, it enhances the binder modulus and interfacial bonding strength through nanoscale effects; on the other hand, it can passivate the stress at the microcrack tip and prevent crack propagation through bridging. The prepared hollow core-shell composite material (i.e., product 2) synergistically improves the material's crack resistance, aging resistance, and energy dissipation capacity, significantly delaying fatigue damage accumulation, and ultimately improving the fatigue resistance and durability of asphalt concrete.

[0021] Secondly, the nano-silica modified with coupling agent and SBS block copolymer construct an organic-inorganic interpenetrating three-dimensional reinforcing network in the asphalt material. This network significantly improves the modulus and strength of the asphalt by means of nanoscale effect, passivates and bridges the tip of microcracks, and greatly hinders the initiation and penetration of fatigue microcracks.

[0022] Through the synergistic effect of the above-mentioned raw materials, the energy dissipation capacity and stress relaxation capacity of asphalt concrete under cyclic loading are significantly enhanced, effectively improving the fatigue resistance and durability of asphalt concrete.

[0023] Secondly, this application provides a method for preparing fatigue-resistant and durable asphalt concrete, employing the following technical solution: A method for preparing fatigue-resistant and durable asphalt concrete includes the following steps: Weigh out each ingredient according to the formula: Basalt with a particle size of 10-15mm, basalt with a particle size of 5-10mm, basalt with a particle size of 3-5mm, basalt with a particle size of 0.01-3mm, and mineral powder are mixed and heated to 170-190℃ for 20-30 minutes to obtain a mixture. Add the preheated asphalt material to the mixture at 160-180℃ and stir for 10-20 minutes at 160-180℃. Then add the modified composite material and stir for 20-30 minutes at 160-170℃ to obtain asphalt concrete.

[0024] In summary, this application includes at least one of the following beneficial technical effects: This application provides a fatigue-resistant and durable asphalt concrete and its preparation method. The material has excellent fatigue resistance and durability. This application significantly improves the fatigue resistance and durability of asphalt concrete by optimizing the combination ratio of mixture, asphalt material and modified composite material, and adjusting the raw materials of modified composite material. Detailed Implementation

[0025] The technical solutions of this application are further illustrated by specific embodiments below. These specific embodiments do not represent a limitation on the scope of protection of this application. Any non-essential modifications and adjustments made by others based on the concept of this application still fall within the scope of protection of this application.

[0026] All raw materials involved in this application are commercially available products, among which, The nano-silica used is hydrophilic nano-silica produced by Jinan Zhiding Welding Materials Co., Ltd., with a particle size of 20nm and a purity of 99.9% by mass. SBS modified bitumen was purchased from Shanxi Yutong Road Materials Co., Ltd., with batch number XW230618PM009; Styrene-butadiene-styrene block copolymer (SBS), CAS No.: 9003-55-8; Basalt, originating from Liyang basalt; Mineral powder, originating from Nanjing, may be of the conventional type in the art, but is preferably limestone mineral powder; The present application will be further described in detail below with reference to embodiments and comparative examples.

[0027] Preparation Example 1:

[0028] Step 1: Preparation of carbon nanospheres The preparation method of the nanocarbon spheres is as follows: 7 kg of glucose and 40 kg of water are mixed, the solution is placed in a high-pressure reactor, and the reaction is carried out at 170°C for 10 hours, followed by centrifugation for 5 minutes; 20 mL of water is added and stirred, then centrifuged again, and water is added again to wash three times. The mixture is then dried at 80°C for 10 hours to obtain nanocarbon spheres.

[0029] Step 2: Preparation of modified composite materials Mix 0.3 kg of carbon nanospheres and 100 kg of ethanol for 30 minutes while stirring continuously, and slowly add 10 kg of tetrabutyl titanate over 1 hour to obtain a suspension. 25 kg of ethanol and 10 kg of water were mixed to obtain an ethanol aqueous solution. The ethanol aqueous solution was added dropwise to the suspension at 60 °C and mixed for 2.5 hours. The mixture was dried at 80 °C for 10 hours and then placed in a muffle furnace and calcined at 600 °C for 2.5 hours to obtain product 1. 3 kg of lanthanum nitrate trihydrate, 5 kg of ferric nitrate nonahydrate, 3 kg of citric acid, and 50 kg of water were mixed for 1.5 hours. Ammonia was added to adjust the pH to 7.5. 3 kg of ethylene glycol was added and mixed for 35 minutes. Product 1 was added and mixed thoroughly. The mixture was heated to 90°C and mixed for 1 hour. The mixture was dried at 105°C for 12 hours and then placed in a muffle furnace and calcined at 600°C for 4 hours to obtain product 2. Product 2 and 1 kg of nano-silica were mixed and dispersed at a high speed of 4000 rpm for 18 minutes. 0.03 kg of silane coupling agent KH-570 and 0.15 kg of ethanol were added and mixed. The mixture was heated to 90°C, stirred at 2500 rpm and kept at that temperature for 50 minutes. The mixed powder was transferred to a mixer, heated to 170°C, and 3 kg of styrene-butadiene-styrene block copolymer (SBS) was added. The mixture was then melt-blended at 180°C and 70 rpm for 40 minutes to obtain the modified composite material.

[0030] Preparation Example 2:

[0031] Step 1: Preparation of carbon nanospheres The preparation method of the nanocarbon spheres is as follows: 5 kg of glucose and 30 kg of water are mixed, the solution is placed in a high-pressure reactor, and the reaction is carried out at 170°C for 10 hours, followed by centrifugation for 5 minutes; 20 mL of water is added and stirred, then centrifuged again, and water is added again to wash three times. The mixture is then dried at 80°C for 10 hours to obtain nanocarbon spheres.

[0032] Step 2: Preparation of modified composite materials Mix 0.1 kg of carbon nanospheres and 80 kg of ethanol for 30 minutes while stirring continuously, and slowly add 5 kg of tetrabutyl titanate over 1 hour to obtain a suspension. 20 kg of ethanol and 5 kg of water were mixed to obtain an ethanol aqueous solution. The ethanol aqueous solution was added dropwise to the suspension at 60 °C and mixed for 2.5 hours. The mixture was dried at 80 °C for 10 hours and then placed in a muffle furnace and calcined at 600 °C for 2.5 hours to obtain product 1. 1 kg of lanthanum nitrate trihydrate, 2 kg of ferric nitrate nonahydrate, 1 kg of citric acid, and 40 kg of water were mixed for 1.5 hours. Ammonia was added to adjust the pH to 7.5. 1 kg of ethylene glycol was added and mixed for 35 minutes. Product 1 was added and mixed thoroughly. The mixture was heated to 90°C and mixed for 1 hour. The mixture was dried at 105°C for 12 hours and then placed in a muffle furnace and calcined at 600°C for 4 hours to obtain product 2. Product 2 and 0.5 kg of nano-silica were mixed and dispersed at a high speed of 4000 rpm for 18 minutes. 0.01 kg of silane coupling agent KH-570 and 0.05 kg of ethanol were added and mixed. The mixture was heated to 90°C, stirred at 2500 rpm and kept at that temperature for 50 minutes. The mixed powder was transferred to a mixer, heated to 170°C, and 1 kg of styrene-butadiene-styrene block copolymer (SBS) was added. The mixture was then melt-blended at 180°C and 70 rpm for 40 minutes to obtain the modified composite material.

[0033] Preparation Example 3:

[0034] Step 1: Preparation of carbon nanospheres The preparation method of the nanocarbon spheres is as follows: 10 kg of glucose and 50 kg of water are mixed, the solution is placed in a high-pressure reactor, and the reaction is carried out at 170°C for 10 hours. After centrifugation for 5 minutes, 20 mL of water is added and stirred, then centrifuged again. Water is added again and the washing is repeated 3 times. The mixture is dried at 80°C for 10 hours to obtain nanocarbon spheres.

[0035] Step 2: Preparation of modified composite materials Mix 0.5 kg of carbon nanospheres and 120 kg of ethanol for 30 minutes while stirring continuously, and slowly add 15 kg of tetrabutyl titanate over 1 hour to obtain a suspension. 30 kg of ethanol and 15 kg of water were mixed to obtain an ethanol aqueous solution. The ethanol aqueous solution was added dropwise to the suspension at 60 °C and mixed for 2.5 hours. The mixture was dried at 80 °C for 10 hours and then placed in a muffle furnace and calcined at 600 °C for 2.5 hours to obtain product 1. 6 kg of lanthanum nitrate trihydrate, 7 kg of ferric nitrate nonahydrate, 6 kg of citric acid, and 60 kg of water were mixed for 1.5 hours. Ammonia was added to adjust the pH to 7.5. 5 kg of ethylene glycol was added and mixed for 35 minutes. Product 1 was added and mixed thoroughly. The mixture was heated to 90°C and mixed for 1 hour. The mixture was dried at 105°C for 12 hours and then placed in a muffle furnace and calcined at 600°C for 4 hours to obtain product 2. Product 2 and 1.5 kg of nano-silica were mixed and dispersed at a high speed of 4000 rpm for 18 minutes. 0.05 kg of silane coupling agent KH-570 and 0.25 kg of ethanol were added and mixed. The mixture was heated to 90°C and stirred at 2500 rpm for 50 minutes. The mixed powder was transferred to a mixer and heated to 170°C. 5 kg of styrene-butadiene-styrene block copolymer (SBS) was added and melt-blended at 180°C and 70 rpm for 40 minutes to obtain the modified composite material.

[0036] Example 1:

[0037] A fatigue-resistant and durable asphalt concrete comprises the following raw materials: 96.06 kg of mixture, 3.94 kg of asphalt material, and 1 kg of modified composite material; The mixture includes the following raw materials: 26 kg of basalt with a particle size of 10-15 mm, 30 kg of basalt with a particle size of 5-10 mm, 9 kg of basalt with a particle size of 3-5 mm, 32 kg of basalt with a particle size of 0.01-3 mm, and 3 kg of mineral powder.

[0038] The modified composite material was prepared in Preparation Example 1.

[0039] The asphalt material is SBS modified asphalt with a relative density of 1.025.

[0040] The basalt with a grain size of 10-15 mm has an apparent relative density of 2.841 and a bulk relative density of 2.789. The basalt with a particle size of 5-10 mm has an apparent relative density of 2.823, a bulk relative density of 2.753, a crushing value of 13.4%, and a content of 8.7% of needle-like and flaky particles. The basalt with a grain size of 3-5 mm has an apparent relative density of 2.809 and a bulk relative density of 2.738. The basalt with a particle size of 0.01-3 mm has an apparent relative density of 2.787, a bulk relative density of 2.687, a water absorption rate of 1.6, and a sand equivalent of 70%. The apparent relative density of the mineral powder is 2.691, and the hydrophilicity coefficient is 0.85.

[0041] A method for preparing fatigue-resistant and durable asphalt concrete includes the following steps: Step 1: Before constructing the asphalt pavement with the target fatigue resistance and durability, prepare the mixture, asphalt material, and modified composite material according to its raw material parameters. In this embodiment, the gradation used is SBS AC-13C. The raw materials and aggregate gradation are shown in Table 1, and the engineering standards for SBS AC-13C type asphalt concrete are shown in Table 2. Table 1. Mixture Gradation Standards

[0042] Table 2 Engineering Standards for SBS AC-13C Asphalt Concrete

[0043] The testing methods for each test item in Table 2 are based on the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011).

[0044] Step 2: Preparation of Asphalt Concrete Weigh out each ingredient according to the formula: Basalt with a particle size of 10-15mm, basalt with a particle size of 5-10mm, basalt with a particle size of 3-5mm, basalt with a particle size of 0.01-3mm, and mineral powder are mixed and heated to 180℃ for 25 minutes to obtain a mixture. Preheated asphalt material to 170°C is added to the mixture and stirred at 170°C for 15 minutes. Modified composite material is then added and stirred at 165°C for 25 minutes to obtain asphalt concrete.

[0045] Example 2:

[0046] A fatigue-resistant and durable asphalt concrete comprises the following raw materials: 95.6 kg of mixture, 4.4 kg of asphalt material, and 1 kg of modified composite material; The mixture includes the following raw materials: 26 kg of basalt with a particle size of 10-15 mm, 30 kg of basalt with a particle size of 5-10 mm, 9 kg of basalt with a particle size of 3-5 mm, 32 kg of basalt with a particle size of 0.01-3 mm, and 3 kg of mineral powder.

[0047] The modified composite material was prepared in Preparation Example 1.

[0048] The asphalt material is SBS modified asphalt with a relative density of 1.025.

[0049] The basalt with a grain size of 10-15 mm has an apparent relative density of 2.841 and a bulk relative density of 2.789. The basalt with a particle size of 5-10 mm has an apparent relative density of 2.823, a bulk relative density of 2.753, a crushing value of 13.4%, and a content of 8.7% of needle-like and flaky particles. The basalt with a grain size of 3-5 mm has an apparent relative density of 2.809 and a bulk relative density of 2.738. The basalt with a particle size of 0.01-3 mm has an apparent relative density of 2.787, a bulk relative density of 2.687, a water absorption rate of 1.6, and a sand equivalent of 70%. The apparent relative density of the mineral powder is 2.691, and the hydrophilicity coefficient is 0.85.

[0050] A method for preparing fatigue-resistant and durable asphalt concrete includes the following steps: Step 1: Same as Example 1; Step 2: Preparation of Asphalt Concrete Weigh out each ingredient according to the formula: Basalt with a particle size of 10-15mm, basalt with a particle size of 5-10mm, basalt with a particle size of 3-5mm, basalt with a particle size of 0.01-3mm, and mineral powder are mixed and heated to 180℃ for 25 minutes to obtain a mixture. Preheated asphalt material to 170°C is added to the mixture and stirred at 170°C for 15 minutes. Modified composite material is then added and stirred at 165°C for 25 minutes to obtain asphalt concrete.

[0051] Example 3:

[0052] A fatigue-resistant and durable asphalt concrete comprises the following raw materials: 95.15 kg of mixture, 4.85 kg of asphalt material, and 1 kg of modified composite material; The mixture includes the following raw materials: 26 kg of basalt with a particle size of 10-15 mm, 30 kg of basalt with a particle size of 5-10 mm, 9 kg of basalt with a particle size of 3-5 mm, 32 kg of basalt with a particle size of 0.01-3 mm, and 3 kg of mineral powder.

[0053] The modified composite material was prepared in Preparation Example 1.

[0054] The asphalt material is SBS modified asphalt with a relative density of 1.025.

[0055] The basalt with a grain size of 10-15 mm has an apparent relative density of 2.841 and a bulk relative density of 2.789. The basalt with a particle size of 5-10 mm has an apparent relative density of 2.823, a bulk relative density of 2.753, a crushing value of 13.4%, and a content of 8.7% of needle-like and flaky particles. The basalt with a grain size of 3-5 mm has an apparent relative density of 2.809 and a bulk relative density of 2.738. The basalt with a particle size of 0.01-3 mm has an apparent relative density of 2.787, a bulk relative density of 2.687, a water absorption rate of 1.6, and a sand equivalent of 70%. The apparent relative density of the mineral powder is 2.691, and the hydrophilicity coefficient is 0.85.

[0056] A method for preparing fatigue-resistant and durable asphalt concrete includes the following steps: Step 1: Same as Example 1; Step 2: Preparation of Asphalt Concrete Weigh out each ingredient according to the formula: Basalt with a particle size of 10-15mm, basalt with a particle size of 5-10mm, basalt with a particle size of 3-5mm, basalt with a particle size of 0.01-3mm, and mineral powder are mixed and heated to 180℃ for 25 minutes to obtain a mixture. Preheated asphalt material to 170°C is added to the mixture and stirred at 170°C for 15 minutes. Modified composite material is then added and stirred at 165°C for 25 minutes to obtain asphalt concrete.

[0057] Example 4:

[0058] A fatigue-resistant and durable asphalt concrete comprises the following raw materials: 94.7 kg of mixture, 5.3 kg of asphalt material, and 1 kg of modified composite material; The mixture includes the following raw materials: 26 kg of basalt with a particle size of 10-15 mm, 30 kg of basalt with a particle size of 5-10 mm, 9 kg of basalt with a particle size of 3-5 mm, 32 kg of basalt with a particle size of 0.01-3 mm, and 3 kg of mineral powder.

[0059] The modified composite material was prepared in Preparation Example 1.

[0060] The asphalt material is SBS modified asphalt with a relative density of 1.025.

[0061] The basalt with a grain size of 10-15 mm has an apparent relative density of 2.841 and a bulk relative density of 2.789. The basalt with a particle size of 5-10 mm has an apparent relative density of 2.823, a bulk relative density of 2.753, a crushing value of 13.4%, and a content of 8.7% of needle-like and flaky particles. The basalt with a grain size of 3-5 mm has an apparent relative density of 2.809 and a bulk relative density of 2.738. The basalt with a particle size of 0.01-3 mm has an apparent relative density of 2.787, a bulk relative density of 2.687, a water absorption rate of 1.6, and a sand equivalent of 70%. The apparent relative density of the mineral powder is 2.691, and the hydrophilicity coefficient is 0.85.

[0062] A method for preparing fatigue-resistant and durable asphalt concrete includes the following steps: Step 1: Same as Example 1; Step 2: Preparation of Asphalt Concrete Weigh out each ingredient according to the formula: Basalt with a particle size of 10-15mm, basalt with a particle size of 5-10mm, basalt with a particle size of 3-5mm, basalt with a particle size of 0.01-3mm, and mineral powder are mixed and heated to 180℃ for 25 minutes to obtain a mixture. Preheated asphalt material to 170°C is added to the mixture and stirred at 170°C for 15 minutes. Modified composite material is then added and stirred at 165°C for 25 minutes to obtain asphalt concrete.

[0063] Example 5:

[0064] A fatigue-resistant and durable asphalt concrete comprises the following raw materials: 94.25 kg of mixture, 5.75 kg of asphalt material, and 1 kg of modified composite material; The mixture includes the following raw materials: 26 kg of basalt with a particle size of 10-15 mm, 30 kg of basalt with a particle size of 5-10 mm, 9 kg of basalt with a particle size of 3-5 mm, 32 kg of basalt with a particle size of 0.01-3 mm, and 3 kg of mineral powder.

[0065] The modified composite material was prepared in Preparation Example 1.

[0066] The asphalt material is SBS modified asphalt with a relative density of 1.025.

[0067] The basalt with a grain size of 10-15 mm has an apparent relative density of 2.841 and a bulk relative density of 2.789. The basalt with a particle size of 5-10 mm has an apparent relative density of 2.823, a bulk relative density of 2.753, a crushing value of 13.4%, and a content of 8.7% of needle-like and flaky particles. The basalt with a grain size of 3-5 mm has an apparent relative density of 2.809 and a bulk relative density of 2.738. The basalt with a particle size of 0.01-3 mm has an apparent relative density of 2.787, a bulk relative density of 2.687, a water absorption rate of 1.6, and a sand equivalent of 70%. The apparent relative density of the mineral powder is 2.691, and the hydrophilicity coefficient is 0.85.

[0068] A method for preparing fatigue-resistant and durable asphalt concrete includes the following steps: Step 1: Same as Example 1; Step 2: Preparation of Asphalt Concrete Weigh out each ingredient according to the formula: Basalt with a particle size of 10-15mm, basalt with a particle size of 5-10mm, basalt with a particle size of 3-5mm, basalt with a particle size of 0.01-3mm, and mineral powder are mixed and heated to 180℃ for 25 minutes to obtain a mixture. Preheated asphalt material to 170°C is added to the mixture and stirred at 170°C for 15 minutes. Modified composite material is then added and stirred at 165°C for 25 minutes to obtain asphalt concrete.

[0069] Example 6:

[0070] A fatigue-resistant and durable asphalt concrete comprises the following raw materials: 90 kg of mixture, 10 kg of asphalt material, and 0.5 kg of modified composite material; The mixture includes the following raw materials: 20 kg of basalt with a particle size of 10-15 mm, 25 kg of basalt with a particle size of 5-10 mm, 5 kg of basalt with a particle size of 3-5 mm, 25 kg of basalt with a particle size of 0.01-3 mm, and 1 kg of mineral powder.

[0071] The modified composite material was prepared in Preparation Example 2.

[0072] The asphalt material is SBS modified asphalt with a relative density of 1.025.

[0073] The basalt with a grain size of 10-15 mm has an apparent relative density of 2.841 and a bulk relative density of 2.789. The basalt with a particle size of 5-10 mm has an apparent relative density of 2.823, a bulk relative density of 2.753, a crushing value of 13.4%, and a content of 8.7% of needle-like and flaky particles. The basalt with a grain size of 3-5 mm has an apparent relative density of 2.809 and a bulk relative density of 2.738. The basalt with a particle size of 0.01-3 mm has an apparent relative density of 2.787, a bulk relative density of 2.687, a water absorption rate of 1.6, and a sand equivalent of 70%. The apparent relative density of the mineral powder is 2.691, and the hydrophilicity coefficient is 0.85.

[0074] A method for preparing fatigue-resistant and durable asphalt concrete includes the following steps: Step 1: Same as Example 1; Step 2: Preparation of Asphalt Concrete Weigh out each ingredient according to the formula: Basalt with a particle size of 10-15mm, basalt with a particle size of 5-10mm, basalt with a particle size of 3-5mm, basalt with a particle size of 0.01-3mm, and mineral powder are mixed and heated to 180℃ for 25 minutes to obtain a mixture. Preheated asphalt material to 170°C is added to the mixture and stirred at 170°C for 15 minutes. Modified composite material is then added and stirred at 165°C for 25 minutes to obtain asphalt concrete.

[0075] Example 7:

[0076] A fatigue-resistant and durable asphalt concrete comprises the following raw materials: 99 kg of mixture, 1 kg of asphalt material, and 1.5 kg of modified composite material; The mixture includes the following raw materials: 30 kg of basalt with a particle size of 10-15 mm, 35 kg of basalt with a particle size of 5-10 mm, 15 kg of basalt with a particle size of 3-5 mm, 37 kg of basalt with a particle size of 0.01-3 mm, and 5 kg of mineral powder.

[0077] The modified composite material was prepared in Preparation Example 2.

[0078] The asphalt material is SBS modified asphalt with a relative density of 1.025.

[0079] The basalt with a grain size of 10-15 mm has an apparent relative density of 2.841 and a bulk relative density of 2.789. The basalt with a particle size of 5-10 mm has an apparent relative density of 2.823, a bulk relative density of 2.753, a crushing value of 13.4%, and a content of 8.7% of needle-like and flaky particles. The basalt with a grain size of 3-5 mm has an apparent relative density of 2.809 and a bulk relative density of 2.738. The basalt with a particle size of 0.01-3 mm has an apparent relative density of 2.787, a bulk relative density of 2.687, a water absorption rate of 1.6, and a sand equivalent of 70%. The apparent relative density of the mineral powder is 2.691, and the hydrophilicity coefficient is 0.85.

[0080] A method for preparing fatigue-resistant and durable asphalt concrete includes the following steps: Step 1: Same as Example 1; Step 2: Preparation of Asphalt Concrete Weigh out each ingredient according to the formula: Basalt with a particle size of 10-15mm, basalt with a particle size of 5-10mm, basalt with a particle size of 3-5mm, basalt with a particle size of 0.01-3mm, and mineral powder are mixed and heated to 180℃ for 25 minutes to obtain a mixture. Preheated asphalt material to 170°C is added to the mixture and stirred at 170°C for 15 minutes. Modified composite material is then added and stirred at 165°C for 25 minutes to obtain asphalt concrete.

[0081] Example 8:

[0082] The difference from Example 3 is that the amount of modified composite material added is 0.5 kg.

[0083] Example 9:

[0084] The difference from Example 3 is that the amount of modified composite material added is 1.5 kg.

[0085] Comparative Example 1:

[0086] The difference from Example 3 is that no modified composite material is added.

[0087] Comparative Example 2:

[0088] The difference from Example 3 is that the amount of modified composite material added is 0.4 kg.

[0089] Comparative Example 3:

[0090] The difference from Example 3 is that the amount of modified composite material added is 1.6 kg.

[0091] Comparative Example 4:

[0092] The difference from Example 3 is that the modified composite material used is different.

[0093] In this comparative example, the modified composite material is replaced by an equal weight of the modified composite material prepared by the following method.

[0094] Take 1 kg of nano-silica and disperse it at a high speed of 4000 rpm for 18 minutes. Add 0.03 kg of silane coupling agent KH-570 and 0.15 kg of ethanol and mix well. Heat to 90℃, stir at 2500 rpm and keep warm for 50 minutes. Transfer the mixed powder to a mixer, heat to 170℃, add 3 kg of styrene-butadiene-styrene block copolymer (SBS), and melt blend at 180℃ and 70 rpm for 40 minutes to obtain the modified composite material.

[0095] Performance testing:

[0096] The following performance tests were conducted in accordance with the provisions of the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTGE20-2011).

[0097] Marshall stability test: Indoor tests were conducted simulating mixing in a mixing plant and on-site construction conditions. Asphalt concrete was prepared using the methods described in the above embodiments and comparative examples. The prepared asphalt concrete was then subjected to Marshall stability tests. The Markovnikov test was conducted at a compaction temperature of 155°C, with 75 compactions on both sides. The test results are shown in the table below.

[0098] Table 3 Performance Test Results

[0099] Based on the test results of Examples 1-7, it can be seen that the asphalt-aggregate ratio affects the overall performance of asphalt concrete. When the asphalt-aggregate ratio is too low, the asphalt film is too thin and the stiffness modulus of the mixture is too high, resulting in a brittle material that is prone to fatigue cracking due to stress concentration under repeated loading. As the asphalt-aggregate ratio approaches the optimal value (e.g., 5.1%), the appropriate asphalt film thickness not only provides strong interfacial adhesion but also endows the material with excellent stress relaxation ability and flexibility, thereby maximally hindering the propagation of microcracks and maximizing fatigue life. However, if the asphalt-aggregate ratio continues to be excessive, the excess free asphalt will weaken the interlocking effect between aggregates, resulting in a low stiffness modulus. Although the pure toughness increases, the load-bearing capacity drops sharply, making it prone to structural fatigue failure with irreversible plastic deformation under heavy load. Therefore, only by achieving a perfect balance between flexible buffering and rigid support at the optimal asphalt-aggregate ratio can asphalt concrete have good fatigue resistance and durability.

[0100] Based on the test results of Examples 1-7, it can be seen that when the asphalt-aggregate ratio is 5.1%, 5.6%, or 6.1%, the prepared asphalt concrete meets the engineering standards for SBS AC-13C type asphalt concrete in Table 2.

[0101] Based on the test results of Example 3 and Comparative Example 1, it can be seen that the test results of Example 3 are better than those of Comparative Example 1, indicating that the addition of modified composite materials effectively improves the comprehensive performance of asphalt concrete, and makes the prepared asphalt concrete have good fatigue resistance and durability.

[0102] Based on the test results of Examples 3, 8, 9, Comparative Example 2, and Comparative Example 3, it can be seen that the amount of modified composite material added affects the overall performance of asphalt concrete, and the overall performance of asphalt concrete is optimal when the amount of modified composite material added is 0.5-1.5 parts by mass.

[0103] Based on the test results of Example 3 and Comparative Example 4, it can be seen that the test results of Example 3 are better than those of Comparative Example 4. This indicates that by improving the formula and adding modified composite materials, the present application significantly enhances the energy dissipation capacity and stress relaxation capacity of asphalt concrete under cyclic loading, and effectively improves the fatigue resistance and structural durability of asphalt concrete.

Claims

1. A fatigue-resistant and durable asphalt concrete, characterized in that: The raw materials include the following parts by weight: 90-99 parts of mixture, 1-10 parts of asphalt material, and 0.5-1.5 parts of modified composite material; The mixture comprises the following raw materials in parts by weight: 20-30 parts of basalt with a particle size of 10-15 mm, 25-35 parts of basalt with a particle size of 5-10 mm, 5-15 parts of basalt with a particle size of 3-5 mm, 25-37 parts of basalt with a particle size of 0.01-3 mm, and 1-5 parts of mineral powder.

2. The fatigue-resistant and durable asphalt concrete according to claim 1, characterized in that: The asphalt concrete comprises the following raw materials in parts by weight: 94-96 parts of mixture, 4-6 parts of asphalt material, and 0.5-1.5 parts of modified composite material; The mixture comprises the following raw materials in parts by weight: 20-30 parts of basalt with a particle size of 10-15 mm, 25-35 parts of basalt with a particle size of 5-10 mm, 5-15 parts of basalt with a particle size of 3-5 mm, 25-37 parts of basalt with a particle size of 0.01-3 mm, and 1-5 parts of mineral powder.

3. The fatigue-resistant and durable asphalt concrete according to claim 2, characterized in that: The asphalt material is SBS modified asphalt with a relative density of 1.

025.

4. The fatigue-resistant and durable asphalt concrete according to claim 2, characterized in that: The basalt with a grain size of 10-15 mm has an apparent relative density of 2.841 and a bulk relative density of 2.

789. The basalt with a grain size of 5-10 mm has an apparent relative density of 2.823 and a bulk relative density of 2.

753. The basalt with a grain size of 3-5 mm has an apparent relative density of 2.809 and a bulk relative density of 2.

738. The basalt with a grain size of 0.01-3 mm has an apparent relative density of 2.787 and a bulk relative density of 2.

687.

5. The fatigue-resistant and durable asphalt concrete according to claim 2, characterized in that: The apparent relative density of the mineral powder is 2.691, and the hydrophilicity coefficient is 0.

85.

6. The fatigue-resistant and durable asphalt concrete according to claim 2, characterized in that: The modified composite material comprises the following raw materials in parts by weight: 0.1-0.5 parts of nano-carbon spheres, 80-120 parts of ethanol (first part), 5-15 parts of tetrabutyl titanate, 20-30 parts of ethanol (second part), 5-15 parts of water (first part), 1-6 parts of lanthanum nitrate trihydrate, 2-7 parts of ferric nitrate nonahydrate, 1-6 parts of citric acid, 40-60 parts of water (second part), 1-5 parts of ethylene glycol, 1-5 parts of styrene-butadiene-styrene block copolymer, 0.5-1.5 parts of nano-silica, and 0.01-0.05 parts of coupling agent.

7. The fatigue-resistant and durable asphalt concrete according to claim 6, characterized in that: The nanocarbon spheres comprise the following raw materials in parts by weight: 5-10 parts glucose and 30-50 parts water.

8. The fatigue-resistant and durable asphalt concrete according to claim 7, characterized in that: The preparation method of the carbon nanospheres is as follows: glucose and a third part of water are mixed and reacted at 160-180℃ for 8-12 hours, then separated and dried to obtain carbon nanospheres.

9. The fatigue-resistant and durable asphalt concrete according to claim 6, characterized in that: The preparation method of the modified composite material is as follows: carbon nanospheres and a first portion of ethanol are mixed, tetrabutyl titanate, a second portion of ethanol and a first portion of water are added and mixed, dried and calcined to obtain product 1. Lanthanum nitrate trihydrate, ferric nitrate nonahydrate, citric acid, and a second portion of water were mixed, ethylene glycol was added and mixed, product 1 was added and mixed, then dried and calcined to obtain product 2. Product 2 and nano-silica were mixed, a coupling agent was added and mixed, and then styrene-butadiene-styrene block copolymer was added and mixed to obtain the modified composite material.

10. A method for preparing fatigue-resistant and durable asphalt concrete, characterized in that: Includes the following steps: Weigh out each ingredient according to the formula: Basalt with a particle size of 10-15mm, basalt with a particle size of 5-10mm, basalt with a particle size of 3-5mm, basalt with a particle size of 0.01-3mm, and mineral powder are mixed and heated to 170-190℃ for 20-30 minutes to obtain a mixture. Add the preheated asphalt material to the mixture at 160-180℃ and stir for 10-20 minutes at 160-180℃. Then add the modified composite material and stir for 20-30 minutes at 160-170℃ to obtain asphalt concrete.

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