Plant fiber-nano titanium carbide composite modified asphalt mixture and preparation method thereof

Abstract

The invention provides a plant fiber-nano titanium carbide composite modified asphalt mixture and a preparation method thereof, and aims to solve the technical problem of reducing high and low temperature diseases and water damage of an asphalt pavement while ensuring the pavement performance of the asphalt mixture. The composite modified asphalt is prepared from the following raw materials in parts by weight: 100 parts of mineral aggregate, 3 to 7 parts of asphalt, 0.02 to 0.08 part of cotton straw fiber, 0.09 to 0.21 part of coconut fiber, 0.03 to 0.07 part of nano titanium carbide, 0.013 to 0.032 part of modifier and 0.12 to 0.28 part of stabilizer. The composite modified asphalt mixture is excellent in performance, simple in preparation process and non-toxic and harmless in raw materials, can improve the high-temperature stability, low-temperature crack resistance and water stability of the asphalt pavement, and has great significance in prolonging the service life of the asphalt pavement; the composite modified asphalt mixture belongs to environment-friendly, non-toxic and non-corrosive composite asphalt, has the advantages of wide raw material source, no pollution in the production process, low price and low cost, and has good economic and social benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of road engineering materials, and in particular to a composite modified asphalt mixture and a preparation method thereof. Background Art

[0002] With the rapid development of highway construction, asphalt pavement has become the most widely used pavement form due to its advantages such as sufficient mechanical strength, smooth and comfortable driving, low vibration, no dust, low noise and easy maintenance. However, due to the increase in extreme weather conditions of high and low temperatures and the uncertainty of the use environment, many existing asphalt pavements on highways are prone to high and low temperature damage and water damage after they are built and put into operation, which greatly shortens the service life of the pavement, causing many highways to enter the overhaul or renovation period ahead of schedule, resulting in a large amount of economic losses. The current technology for asphalt pavements to deal with high and low temperatures is mainly high-temperature road surface cooling coatings and other means, but it cannot take into account the damage caused to the pavement by high and low temperatures at the same time, and is not comprehensive. Therefore, it is particularly critical to develop a new type of modified asphalt mixture to solve the high and low temperature problems of the pavement.

[0003] The information disclosed in this background technology section is only used to deepen the understanding of the background technology of the present disclosure, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art known to those skilled in the art. Summary of the invention

[0004] The present application provides a plant fiber-nano titanium carbide composite modified asphalt mixture and a preparation method thereof, aiming to solve the technical problem of reducing high and low temperature diseases and water damage of asphalt pavement while ensuring the road performance of the asphalt mixture.

[0005] According to one aspect of the present disclosure, a plant fiber-nano titanium carbide composite modified asphalt mixture is provided, which is made of the following raw materials in parts by weight: 100 parts of mineral material, 3 to 7 parts of asphalt, 0.02 to 0.08 parts of cotton straw fiber, 0.09 to 0.21 parts of coconut shell fiber, 0.03 to 0.07 parts of nano titanium carbide, 0.013 to 0.032 parts of modifier, and 0.12 to 0.28 parts of stabilizer.

[0006] In some embodiments of the present disclosure, the plant fiber-nano titanium carbide composite modified asphalt mixture is made of the following raw materials in parts by weight: 100 parts of mineral material, 4 to 6 parts of asphalt, 0.02 to 0.04 parts of cotton straw fiber, 0.12 to 0.18 parts of coconut shell fiber, 0.04 to 0.06 parts of nano titanium carbide, 0.018 to 0.026 parts of modifier, and 0.16 to 0.24 parts of stabilizer.

[0007] In some embodiments of the present disclosure, the plant fiber-nano titanium carbide composite modified asphalt mixture is made of the following raw materials in parts by weight: 100 parts of mineral material, 4.3 parts of asphalt, 0.06 parts of cotton straw fiber, 0.129 parts of coconut shell fiber, 0.043 parts of nano titanium carbide, 0.019 parts of modifier, and 0.172 parts of stabilizer.

[0008] In some embodiments of the present disclosure, the asphalt is at least one of road petroleum asphalt, coal asphalt, SBS modified asphalt, PE modified asphalt or SBR modified asphalt.

[0009] In some embodiments of the present disclosure, the modifier is a silane coupling agent.

[0010] In some embodiments of the present disclosure, the mineral material consists of coarse aggregate, fine aggregate and mineral powder.

[0011] In some embodiments of the present disclosure, the stabilizer is furfural extracted oil.

[0012] According to a second aspect of the present disclosure, a method for preparing a plant fiber-nano titanium carbide composite modified asphalt mixture is provided, comprising the following steps: (1) Raw material preparation: Prepare the raw materials according to the above weight ratio and set aside; (2) Preparation of nano-titanium carbide modifier: Prepare nano-titanium carbide, modifier, water and ethanol in a mass ratio of 1:0.03-0.07:0.1-0.5:1.0-1.4, first mix the modifier with ethanol and water evenly and let it stand for 15-25 minutes, then add nano-titanium carbide and soak for 55-65 minutes, filter out excess liquid and dry at 50-70°C to obtain nano-titanium carbide modifier; (3) Preparation of composite modified asphalt: Heat and melt the asphalt, first add the nano titanium carbide modifier, stir evenly with high-speed shearing, then add coconut shell fiber and cotton straw fiber, stir for 40 to 60 minutes, and then place it in an environment of 145 to 165°C to swell and develop for 25 to 35 minutes. (4) Preparation of composite modified asphalt mixture: Mix the mineral material heated to 170°C to 175°C and the composite modified asphalt and stir them evenly to obtain the composite modified asphalt mixture.

[0013] In some embodiments of the present disclosure, the shear treatment process in step (3) is: adding nano-titanium carbide and shearing at a shear rate of 4000-5000 r / min for 15-25 minutes, and then adding cotton straw fiber and coconut shell fiber and stirring at a shear rate of 5000-6000 r / min for 40-45 minutes.

[0014] One or more technical solutions provided in the embodiments of the present application have at least any of the following technical effects: 1. The modified asphalt mixture of nano-titanium carbide, cotton straw fiber and coconut shell fiber in this application can give full play to their respective advantages and form a synergistic effect; nano-titanium carbide provides high strength and high stability, cotton straw fiber and coconut shell fiber increase toughness and crack resistance, and the three together improve the overall performance of the asphalt mixture: the addition of nano-titanium carbide, cotton straw fiber and coconut shell fiber can increase the toughness of the asphalt mixture and reduce cracks caused by temperature changes or loads; the high modulus and hardness of nano-titanium carbide and the reinforcing effect of the fiber material jointly improve the shear strength and resistance to permanent deformation of the asphalt mixture, thereby enhancing its anti-rutting performance; the addition of the two plant fiber materials can form a stable network structure, which helps to reduce the erosion of water on the asphalt mixture and improve its resistance to water damage.

[0015] 2. In the nano-titanium carbide modifier of the present application, the surface of nano-titanium carbide is pretreated by using a silane coupling agent in combination with ethanol and water, which can enhance the dispersion of nano-titanium carbide in the matrix (nano-titanium carbide is prone to agglomeration in the matrix due to its high surface energy, affecting performance), improve the interfacial bonding force between nano-titanium carbide and the asphalt matrix, and thus improve the performance of the composite material (increase mechanical properties, such as strength, toughness, hardness, etc. can be significantly improved; improve thermal stability and weather resistance, silane coupling agent can form a stable interface layer between nano-titanium carbide and the matrix, prevent the intrusion of harmful substances such as moisture and oxygen, thereby improving the thermal stability and weather resistance of the composite material).

[0016] 3. The cotton straw fiber in this application is a natural, renewable and environmentally friendly material with good softness, good bearing capacity and stability, and is not easily affected by moisture or rot; coconut shell fiber has high toughness and strength, and has the characteristics of water resistance and mildew resistance. Coconut shell fiber contains rich pore structure and has good adsorption performance; the softness and easy processing of cotton straw fiber can complement the toughness and strength of coconut shell fiber, making the mixed material more comprehensive and superior in performance.

[0017] 4. The nano-titanium carbide modifier obtained in the process of this application can be connected with cotton straw fiber and coconut shell fiber inside the asphalt mixture to form a specific mesh connection structure, thereby enhancing the mechanical strength, impact resistance and stability of the asphalt mixture. The asphalt modified by the composite of cotton straw fiber, coconut shell fiber and nano-titanium carbide has a higher viscosity and can be evenly wrapped on the surface of the aggregate, which improves the interlocking force between the aggregates; at the same time, it has a stronger deformation recovery ability, which significantly improves the high and low temperature performance, water damage resistance and fatigue damage resistance of the asphalt mixture. The reinforcing effect of cotton straw fiber and coconut shell fiber combined with the modification effect of nano-titanium carbide can significantly improve the mechanical properties and performance of the asphalt mixture; the specific stable structure formed by the three materials in the asphalt can support each other and jointly resist the erosion and damage of the external environment. This synergistic stabilization effect helps to extend the service life of the asphalt pavement. DETAILED DESCRIPTION

[0018] In order to better understand the technical solution of the present application, the above technical solution will be described in detail below in conjunction with specific implementation methods.

[0019] Unless otherwise specified, the raw materials and preparations involved in the following examples are all commercially available conventional raw materials; the preparation methods, detection methods and experimental methods involved are all conventional methods unless otherwise specified.

[0020] In the following examples, the plant fiber-nano titanium carbide composite modified asphalt mixture includes the following preparation steps: Prepare the raw materials according to the weight ratio of 100 parts of mineral material, 3 to 7 parts of asphalt, 0.02 to 0.08 parts of cotton straw fiber, 0.09 to 0.21 parts of coconut shell fiber, 0.03 to 0.07 parts of nano titanium carbide, 0.013 to 0.032 parts of modifier, and 0.12 to 0.28 parts of stabilizer; (1) Preparation of nano-titanium carbide modifier: Nano-titanium carbide, modifier, water and ethanol are prepared in a mass ratio of 1:0.05:0.3:1.2. The modifier is first diluted with ethanol and water to a concentration of 2%. After standing for hydrolysis for 20 minutes, nano-titanium carbide is added, mixed evenly and soaked for 60 minutes. After filtering, the mixture is dried at 60°C to obtain the nano-titanium carbide modifier.

[0021] (2) Preparation of composite modified asphalt: Heat the base asphalt to melt (165-185°C), first add the nano titanium carbide modifier prepared in step (1), shear for 20 min at a shear rate of 4000-5000 r / min, add coconut shell fiber and cotton straw fiber after shearing and stirring, shear for 45 min at a shear rate of 5000-6000 r / min, and then place it in an environment of 145-165°C to swell and develop for 30 min.

[0022] (3) Preparation of composite modified asphalt mixture: Mix the mineral material heated to 170-175°C and the cotton straw fiber, coconut shell fiber and nano-titanium carbide composite modified asphalt obtained above and stir evenly to obtain the mixture.

[0023] Example 1. A plant fiber-nano titanium carbide composite modified asphalt mixture is made of the following raw materials in parts by weight: 100 parts of AC-13 mineral material, 3 parts of SBS asphalt, 0.02 parts of cotton straw fiber, 0.09 parts of coconut shell fiber, 0.03 parts of nano titanium carbide, 0.013 parts of modifier (silane coupling agent), and 0.12 parts of stabilizer (furfural extracted oil).

[0024] Example 2. A plant fiber-nano titanium carbide composite modified asphalt mixture is made from the following raw materials in parts by weight: 100 parts of AC-13 mineral material, 4 parts of coal tar, 0.035 parts of cotton straw fiber, 0.12 parts of coconut shell fiber, 0.04 parts of nano titanium carbide, 0.018 parts of modifier (silane coupling agent), and 0.16 parts of stabilizer (furfural extracted oil).

[0025] Example 3. A plant fiber-nano titanium carbide composite modified asphalt mixture is made from the following raw materials in parts by weight: 100 parts of AC-13 mineral material, 5.0 parts of road petroleum asphalt, 0.04 parts of cotton straw fiber, 0.15 parts of coconut shell fiber, 0.05 parts of nano titanium carbide, 0.022 parts of modifier (silane coupling agent), and 0.20 parts of stabilizer (furfural extracted oil).

[0026] Example 4. A plant fiber-nano titanium carbide composite modified asphalt mixture is made from the following raw materials in parts by weight: 100 parts of AC-13 mineral material, 5.5 parts of PE modified asphalt, 0.05 parts of cotton straw fiber, 0.165 parts of coconut shell fiber, 0.055 parts of nano-titanium carbide, 0.024 parts of modifier (silane coupling agent), and 0.22 parts of stabilizer (furfural extracted oil).

[0027] Example 5. A plant fiber-nano titanium carbide composite modified asphalt mixture is made from the following raw materials in parts by weight: 100 parts of AC-13 mineral material, 6 parts of SBR modified asphalt, 0.055 parts of cotton straw fiber, 0.18 parts of coconut shell fiber, 0.06 parts of nano titanium carbide, 0.026 parts of modifier (silane coupling agent), and 0.24 parts of stabilizer (furfural extracted oil).

[0028] Example 6. A plant fiber-nano titanium carbide composite modified asphalt mixture is made from the following raw materials in parts by weight: 100 parts of AC-13 mineral material, 4.3 parts of fiber-modified asphalt, 0.06 parts of cotton straw fiber, 0.129 parts of coconut shell fiber, 0.043 parts of nano-titanium carbide, 0.019 parts of modifier (silane coupling agent), and 0.172 parts of stabilizer (furfural extracted oil).

[0029] Example 7. A plant fiber-nano titanium carbide composite modified asphalt mixture is made from the following raw materials in parts by weight: 100 parts of AC-13 mineral material, 7 parts of road petroleum asphalt, 0.07 parts of cotton straw fiber, 0.21 parts of coconut shell fiber, 0.07 parts of nano titanium carbide, 0.032 parts of modifier (silane coupling agent), and 0.28 parts of stabilizer (furfural extracted oil).

[0030] Example 8. A plant fiber-nano titanium carbide composite modified asphalt mixture is made from the following raw materials in parts by weight: 100 parts of AC-13 mineral material, 6.5 parts of SBS modified asphalt, 0.08 parts of cotton straw fiber, 0.195 parts of coconut shell fiber, 0.065 parts of nano titanium carbide, 0.029 parts of modifier (silane coupling agent), and 0.26 parts of stabilizer (furfural extracted oil).

[0031] Comparative Example 1. A common asphalt mixture is made from the following raw materials in parts by weight: 100 parts of AC-13 mineral material and 4.5 parts of SBS asphalt.

[0032] The asphalt mixtures in Examples 1-8 and Comparative Example 1 were subjected to road performance tests, including a high temperature rutting test, a low temperature beam bending test (-10°C), a freeze-thaw splitting test, and a water immersion Marshall test, to test the performance of the composite modified asphalt mixture of the present invention, and compared with ordinary asphalt without adding a modifier (Comparative Example 1). The test results are shown in Table 1.

[0033] Table 1 Asphalt mixture performance test .

[0034] As can be seen from Table 1, the dynamic stability of the composite modified asphalt mixture is much greater than that of ordinary asphalt (Comparative Example 1), indicating that the high-temperature stability of the composite modified asphalt mixture is stronger than that of ordinary asphalt; the low-temperature bending strain of the composite modified asphalt mixture is much greater than that of ordinary asphalt, indicating that the low-temperature stability of the composite modified asphalt mixture is stronger; the residual stability of the composite modified asphalt mixture is greater than that of ordinary asphalt, indicating that the composite modified asphalt mixture can still maintain better performance than ordinary asphalt after being affected by high temperature and traffic loads for a long time; the freeze-thaw splitting strength ratio of the composite modified asphalt mixture is greater than that of ordinary asphalt, indicating that the composite modified asphalt mixture has higher water stability and low-temperature stability.

[0035] The composite modified asphalt mixture of the present application meets the relevant requirements of the Ministry of Transport standard JTG F40-2004 "Technical Specifications for Highway Asphalt Pavement Construction", and its high temperature performance, low temperature performance, water stability and other indicators are significantly higher than those of ordinary asphalt mixtures, indicating that the composite modified asphalt mixture of the present invention has excellent road performance.

[0036] The present application has been described in detail above in conjunction with the embodiments; however, those skilled in the art will appreciate that, without departing from the spirit and scope of the present invention, the specific parameters in the above embodiments may be changed, or the relevant materials and method steps may be replaced by equivalents, thereby forming multiple specific embodiments, which are all within the common variation range of the present application and will not be described in detail one by one here.

Claims

1. A plant fiber-nano titanium carbide composite modified asphalt mixture, characterized in that: The invention is prepared from the following raw materials in parts by weight: 100 parts of mineral material, 3-7 parts of asphalt, 0.02-0.08 parts of cotton straw fiber, 0.09-0.21 parts of coconut shell fiber, 0.03-0.07 parts of nano titanium carbide, 0.013-0.032 parts of modifier and 0.12-0.28 parts of stabilizer.

2. The plant fiber-nano titanium carbide composite modified asphalt mixture according to claim 1, characterized in that: The invention is prepared from the following raw materials in parts by weight: 100 parts of mineral material, 4-6 parts of asphalt, 0.02-0.04 parts of cotton straw fiber, 0.12-0.18 parts of coconut shell fiber, 0.04-0.06 parts of nano titanium carbide, 0.018-0.026 parts of modifier and 0.16-0.24 parts of stabilizer.

3. The plant fiber-nano titanium carbide composite modified asphalt mixture according to claim 1, characterized in that: The invention is prepared from the following raw materials in parts by weight: 100 parts of mineral material, 4.3 parts of asphalt, 0.06 parts of cotton straw fiber, 0.129 parts of coconut shell fiber, 0.043 parts of nano titanium carbide, 0.019 parts of modifier and 0.172 parts of stabilizer.

4. The plant fiber-nano titanium carbide composite modified asphalt mixture according to claim 1, characterized in that: The asphalt is at least one of road petroleum asphalt, coal asphalt, SBS modified asphalt, PE modified asphalt, SBR modified asphalt or fiber modified asphalt.

5. The plant fiber-nano titanium carbide composite modified asphalt mixture according to claim 1, characterized in that: The modifier is a silane coupling agent.

6. The plant fiber-nano titanium carbide composite modified asphalt mixture according to claim 1, characterized in that: The stabilizer is furfural extracted oil.

7. The plant fiber-nano titanium carbide composite modified asphalt mixture according to claim 1, characterized in that: The mineral material consists of coarse aggregate, fine aggregate and mineral powder.

8. A method for preparing the plant fiber-nano titanium carbide composite modified asphalt mixture according to claim 1, characterized in that: The steps include: (1) Raw material preparation: prepare the raw materials according to the weight ratio described in claim 1 and set aside; (2) Preparation of nano-titanium carbide modifier: Prepare nano-titanium carbide, modifier, water and ethanol in a mass ratio of 1:0.03-0.07:0.1-0.5:1.0-1.4, first mix the modifier with ethanol and water evenly and let it stand for 15-25 minutes, then add nano-titanium carbide and soak for 55-65 minutes, filter out excess liquid and dry at 50-70°C to obtain nano-titanium carbide modifier; (3) Preparation of composite modified asphalt: heat and melt the asphalt, first add the nano titanium carbide modifier, stir evenly with high-speed shearing, then add coconut shell fiber and cotton straw fiber, stir for 40 to 60 minutes, then place it in an environment of 145 to 165°C to swell and develop for 25 to 35 minutes, and obtain the composite modified asphalt; (4) Preparation of composite modified asphalt mixture: Mix the mineral material heated to 170°C to 175°C and the composite modified asphalt and stir them evenly to obtain the composite modified asphalt mixture.

9. The preparation method according to claim 8, characterized in that: In step (3), the shearing process is as follows: adding nano-titanium carbide and shearing at a shear rate of 4000-5000 r / min for 15-25 min, and then adding cotton straw fiber and coconut shell fiber and stirring at a shear rate of 5000-6000 r / min for 40-45 min.