Long-life asphalt mixture based on addition of basalt fibers and method for its production and use

Abstract

The present application relates to the technical field of asphalt mixture, and particularly relates to long-life asphalt mixture based on added basalt fiber and a preparation method and application thereof.The long-life asphalt mixture based on added basalt fiber comprises 50-60 parts of asphalt, 1-5 parts of basalt fiber, 450-500 parts of aggregate, 10-20 parts of filler and 1-3 parts of rattan bark powder.The filler and rattan bark powder are used in combination, which can significantly improve the adhesion between the asphalt and the aggregate, form a more solid bonding interface, enable the asphalt to better penetrate the surface of the aggregate, form a tight wrapping layer, and thus improve the overall strength and wear resistance of the mixture.In summary, the asphalt mixture has excellent water permeability and wear resistance, and can prolong the service life thereof.

Description

Technical Field

[0001] This invention relates to the field of asphalt mixture technology, and in particular to long-life asphalt mixtures based on the addition of basalt fibers, their preparation methods, and applications. Background Technology

[0002] With the continuous increase in traffic volume and the increasing weight of vehicles, the requirements for road materials are becoming increasingly stringent. Asphalt, a viscoelastic-plastic material, possesses good adhesion and a certain degree of elasticity, and is a key component of asphalt mixtures. Although traditional asphalt mixtures have good workability and a certain degree of durability, their service life and performance often fail to meet the demands of modern transportation under complex environments such as long-term heavy loads, high and low temperatures, and water damage. Therefore, developing a long-life, high-performance asphalt mixture is particularly important.

[0003] Basalt fiber, primarily composed of silicon-oxygen tetrahedra and aluminum-oxygen tetrahedra connected by shared oxygen vertices to form a continuous linear structure, is a novel high-performance fiber material widely used in road engineering due to its excellent properties such as high strength, high modulus, corrosion resistance, and wear resistance. However, while the addition of basalt fiber can improve the performance of mixtures to some extent, it often fails to achieve the desired overall effect and is costly to produce.

[0004] Therefore, how to regulate the composition design of asphalt mixtures to effectively improve their permeability, wear resistance, and mechanical properties has become a key issue that urgently needs to be addressed. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, one of the objectives of this invention is to provide long-life asphalt mixtures based on the addition of basalt fibers. This invention, through the innovative introduction of fillers and rattan bark powder, significantly improves the permeability and abrasion resistance of the asphalt mixture, meeting the high requirements of modern transportation for road materials.

[0006] The second objective of this invention is to provide a method for preparing long-life asphalt mixtures based on the addition of basalt fibers. This preparation method and its application also have advantages such as environmental protection and sustainability, which are of great significance for promoting the innovation and development of road engineering materials.

[0007] The third objective of this invention is to provide applications of long-life asphalt mixtures based on the addition of basalt fibers.

[0008] One of the objectives of this invention is achieved through the following technical solution:

[0009] Long-life asphalt mixture based on the addition of basalt fiber includes 50-60 parts asphalt, 1-5 parts basalt fiber, 450-500 parts aggregate, 10-20 parts filler, and 1-3 parts rattan bark powder.

[0010] Furthermore, the preparation process of the filler is as follows:

[0011] (1) Take mullite whiskers and pre-treat them;

[0012] (2) Take a mixed solution of magnesium nitrate and ferric nitrate and add it to a sodium hydroxide solution, stir and mix evenly to obtain a mixed solution;

[0013] (3) Add the pretreated mullite whiskers from step (1) to the mixture from step (2), stir and mix evenly, and then carry out a hydrothermal reaction to obtain the final product.

[0014] Further, the pretreatment process described in step (1) is as follows: mullite whiskers are added to a mixed solvent and heated, and then the reaction solution is filtered, washed and dried to obtain the final product.

[0015] Furthermore, the mixed solvent is prepared by anhydrous ethanol and acetone in a volume ratio of 1:(1-2), and the heating temperature is 75-85℃ for 3-5 hours.

[0016] Further, in step (2), the mass ratio of magnesium nitrate, ferric nitrate, sodium hydroxide and water is 1:(0.4-0.8):(0.5-0.9):(45-55).

[0017] Furthermore, in step (3), the mass ratio of the pretreated mullite whiskers to the magnesium nitrate in the mixture obtained in step (2) is 1:(3-8).

[0018] Furthermore, in step (3), the temperature of the hydrothermal reaction is 110-120℃ and the time is 24-30h.

[0019] Furthermore, the mullite whiskers have a diameter of 0.2-3 μm and a length of 5-200 μm; the aggregate has a particle size of 0.5-2.5 mm.

[0020] Furthermore, the basalt fibers are 10-25 mm in length.

[0021] Furthermore, the asphalt is Grade 70 A asphalt.

[0022] The second objective of this invention is achieved by the following technical solution:

[0023] The preparation method of long-life asphalt mixture based on the addition of basalt fiber includes the following steps:

[0024] a. Mix the basalt fiber, aggregate, filler, and rattan bark powder evenly according to the above-mentioned weight proportions to obtain a mixture;

[0025] b. Add the above mixture to the asphalt, heat at 160-170℃ and stir until homogeneous to obtain the final product.

[0026] The third objective of this invention is achieved by the following technical solution:

[0027] Application of long-life asphalt mixtures with added basalt fibers in road engineering construction.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1. This invention provides a long-life asphalt mixture based on the addition of basalt fibers. This mixture innovatively incorporates a filler made from mullite whiskers. The pretreated mullite whiskers impart a larger specific surface area to the filler, which is then compounded with magnesium nitrate and ferric nitrate via a hydrothermal process. The combination of this filler and rattan bark powder improves the water absorption rate and permeability of the asphalt mixture. Furthermore, the addition of the filler significantly enhances the adhesion between asphalt and aggregates, forming a stronger bonding interface. This allows the asphalt to better penetrate the aggregate surface, forming a tight coating layer, thereby improving the overall strength and wear resistance of the mixture.

[0030] 2. This invention increases the strength of asphalt mixtures by adding basalt fibers, significantly improving pavement durability and extending its service life. Basalt fibers possess high strength, high corrosion resistance, and good dispersibility, effectively enhancing the crack resistance, fatigue resistance, and water damage resistance of asphalt pavements. The preparation method of this invention is simple, easy to implement, and low in cost, making it suitable for large-scale application. Detailed Implementation

[0031] The present invention will now be further described in conjunction with specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. Specific conditions not specified in the embodiments shall be performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, all reagents or instruments used are conventional products obtained through commercial channels.

[0032] In the embodiments and comparative examples of this invention, the length of the basalt fibers is 10-25 mm; the asphalt is No. 70 Grade A asphalt; the diameter of the mullite whiskers is 0.2-3 μm and the length is 5-200 μm; and the particle size of the aggregate is 0.5-2.5 mm.

[0033] Example 1

[0034] Long-life asphalt mixture based on the addition of basalt fiber includes 55 parts asphalt, 3 parts basalt fiber, 470 parts aggregate, 18 parts filler, and 2 parts rattan bark powder.

[0035] The preparation process of the filler is as follows:

[0036] (1) Add mullite whiskers to a mixed solvent (anhydrous ethanol and acetone are mixed in a volume ratio of 1:1), heat at 80°C for 4 hours, and then filter, wash and dry the reaction solution to obtain pretreated mullite whiskers.

[0037] (2) According to the mass ratio of magnesium nitrate, ferric nitrate, sodium hydroxide and water of 1:0.6:0.7:50, take half of the total water volume above, add magnesium nitrate and ferric nitrate to it to obtain a mixed solution of magnesium nitrate and ferric nitrate, and then add sodium hydroxide to the remaining water to obtain a sodium hydroxide solution. Under a nitrogen atmosphere, stir the mixed solution and the sodium hydroxide solution to mix evenly to obtain a mixed liquid.

[0038] (3) Add the pretreated mullite whiskers from step (1) to the mixture from step (2), wherein the mass ratio of the pretreated mullite whiskers to the magnesium nitrate in the mixture from step (2) is 1:5; under a nitrogen atmosphere, stir for 30 min and then add it to the reactor, and hydrothermally react at 115℃ for 28 h. Centrifuge the reaction solution at 10000 rpm for 10 min, and wash the precipitate three times with deionized water to obtain the final product.

[0039] The rattan bark powder includes the following preparation steps: take the outer bark of healthy Celastrus orbiculatus, dry it, then place it in a high-energy ball mill for grinding, and after spray drying, obtain rattan bark powder with a particle size of 100-200nm.

[0040] This embodiment also provides a method for preparing long-life asphalt mixtures based on the addition of basalt fibers, including the following steps:

[0041] a. Mix the basalt fiber, aggregate, filler, and rattan bark powder evenly according to the above-mentioned weight proportions to obtain a mixture;

[0042] b. Add the above mixture to the asphalt, heat at 165°C and stir until homogeneous to obtain the final product.

[0043] Example 2

[0044] Long-life asphalt mixture based on the addition of basalt fiber includes 50 parts asphalt, 1 part basalt fiber, 450 parts aggregate, 10 parts filler, and 1 part rattan bark powder.

[0045] The preparation process of the filler is as follows:

[0046] (1) Add mullite whiskers to a mixed solvent (anhydrous ethanol and acetone are mixed in a volume ratio of 1:1.5), heat at 75°C for 5 hours, and then filter, wash and dry the reaction solution to obtain the pretreated mullite whiskers.

[0047] (2) According to the mass ratio of magnesium nitrate, ferric nitrate, sodium hydroxide and water of 1:0.4:0.5:45, take half of the total water volume above and add magnesium nitrate and ferric nitrate to it to obtain a mixed solution of magnesium nitrate and ferric nitrate. Then add sodium hydroxide to the remaining water to obtain a sodium hydroxide solution. Under a nitrogen atmosphere, stir the mixed solution and the sodium hydroxide solution to mix evenly to obtain a mixed liquid.

[0048] (3) Add the pretreated mullite whiskers from step (1) to the mixture from step (2), wherein the mass ratio of the pretreated mullite whiskers to the magnesium nitrate in the mixture from step (2) is 1:3; under a nitrogen atmosphere, stir for 30 min and then add it to the reactor, and perform a hydrothermal reaction at 110°C for 30 h. Centrifuge the reaction solution at 10000 rpm for 10 min, and wash the precipitate three times with deionized water to obtain the final product.

[0049] The rattan bark powder includes the following preparation steps: take the outer bark of healthy Celastrus orbiculatus, dry it, then place it in a high-energy ball mill for grinding, and after spray drying, obtain rattan bark powder with a particle size of 100-200nm.

[0050] This embodiment also provides a method for preparing long-life asphalt mixtures based on the addition of basalt fibers, including the following steps:

[0051] a. Mix the basalt fiber, aggregate, filler, and rattan bark powder evenly according to the above-mentioned weight proportions to obtain a mixture;

[0052] b. Add the above mixture to the asphalt, heat at 160°C and stir until homogeneous to obtain the final product.

[0053] Example 3

[0054] Long-life asphalt mixture based on the addition of basalt fiber includes 60 parts asphalt, 5 parts basalt fiber, 500 parts aggregate, 20 parts filler, and 3 parts rattan bark powder.

[0055] The preparation process of the filler is as follows:

[0056] (1) Add mullite whiskers to a mixed solvent (anhydrous ethanol and acetone are mixed in a volume ratio of 1:2), heat at 85°C for 3 hours, and then filter, wash and dry the reaction solution to obtain pretreated mullite whiskers.

[0057] (2) According to the mass ratio of magnesium nitrate, ferric nitrate, sodium hydroxide and water of 1:0.8:0.9:55, take half of the total water volume above and add magnesium nitrate and ferric nitrate to it to obtain a mixed solution of magnesium nitrate and ferric nitrate. Then add sodium hydroxide to the remaining water to obtain a sodium hydroxide solution. Under a nitrogen atmosphere, stir the mixed solution and the sodium hydroxide solution to mix evenly to obtain a mixed liquid.

[0058] (3) Add the pretreated mullite whiskers from step (1) to the mixture from step (2), wherein the mass ratio of the pretreated mullite whiskers to the magnesium nitrate in the mixture from step (2) is 1:8; under a nitrogen atmosphere, stir for 30 min and then add it to the reactor, and hydrothermally react at 120°C for 24 h. Centrifuge the reaction solution at 10000 rpm for 10 min, and wash the precipitate three times with deionized water to obtain the final product.

[0059] The rattan bark powder includes the following preparation steps: take the outer bark of healthy Celastrus orbiculatus, dry it, then place it in a high-energy ball mill for grinding, and after spray drying, obtain rattan bark powder with a particle size of 100-200nm.

[0060] This embodiment also provides a method for preparing long-life asphalt mixtures based on the addition of basalt fibers, including the following steps:

[0061] a. Mix the basalt fiber, aggregate, filler, and rattan bark powder evenly according to the above-mentioned weight proportions to obtain a mixture;

[0062] b. Add the above mixture to the asphalt, heat at 170°C and stir until homogeneous to obtain the final product.

[0063] Comparative Example 1

[0064] This comparative example provides a long-life asphalt mixture based on the addition of basalt fiber. The only difference from Example 1 is that the preparation process of the filler is as follows: according to the mass ratio of magnesium nitrate, ferric nitrate, sodium hydroxide and water of 1:0.6:0.7:50, half of the total water volume is taken and magnesium nitrate and ferric nitrate are added to it to obtain a mixed solution of magnesium nitrate and ferric nitrate. Then, sodium hydroxide is added to the remaining water to obtain a sodium hydroxide solution. Under a nitrogen atmosphere, the mixed solution and the sodium hydroxide solution are stirred and mixed evenly to obtain a mixed liquid. It is added to a reaction vessel and hydrothermally reacted at 115°C for 28 hours. The reaction liquid is centrifuged at 10,000 rpm for 10 minutes. The precipitate is washed three times with deionized water to obtain the filler. Everything else is the same as in Example 1.

[0065] Comparative Example 2

[0066] This comparative example provides a long-life asphalt mixture based on the addition of basalt fiber. The only difference from Example 1 is that the preparation process of the filler is as follows: the pretreated mullite whiskers and the filler prepared in Comparative Example 1 are stirred and mixed evenly to obtain the final product. Everything else is the same as in Example 1.

[0067] Comparative Example 3

[0068] This comparative example provides a long-life asphalt mixture based on the addition of basalt fiber. The difference from Example 1 is that the rattan bark powder is omitted, while everything else is the same as Example 1.

[0069] Experimental Example 1

[0070] (1) The permeability coefficient, freeze-thaw splitting tensile strength ratio and Marshall stability of the asphalt mixtures of Examples 1-3 and Comparative Examples 1-3 were tested according to the test methods of JTG-E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering".

[0071] (2) The wear of the asphalt mixtures in Examples 1-3 and Comparative Examples 1-3 was tested using a universal friction and wear tester. The load was set at 50 N, the rotation speed at 180 r / min, and the test time was controlled at 2 h. The test results are shown in Table 1.

[0072] Table 1

[0073]

[0074] As shown in Table 1, the permeability coefficient, freeze-thaw splitting strength ratio, stability, and wear amount of Examples 1-3 of the present invention are all superior to those of Comparative Examples 1-3. The asphalt mixtures of Examples 1-3 have good wear resistance, permeability, mechanical properties, and stability, and have better durability and service life.

[0075] The freeze-thaw splitting strength ratio is one of the important indicators for evaluating the water stability of asphalt mixtures. It refers to the ratio of the splitting strength of asphalt mixture specimens before and after water damage following freeze-thaw cycles. Compared with Example 1, Comparative Example 1 omitted the addition of mullite whiskers, Comparative Example 2 changed the filler preparation method, and Comparative Example 3 omitted the addition of rattan bark powder. The permeability coefficient, freeze-thaw splitting strength ratio, Marshall stability, and abrasion resistance of the asphalt mixtures all showed a significant decrease. The reason for these results is that mullite whiskers have high strength, high toughness, and high heat resistance, and after pretreatment, they give the filler a larger specific surface area. This large specific surface area filler can more effectively combine with asphalt, aggregates, and other components in the asphalt mixture to form a denser structure, thereby improving the overall performance of the mixture. The combined use of rattan bark powder and filler can improve the water absorption rate and permeability of the asphalt mixture. It can drain water better when it comes into contact with water, reducing water damage. At the same time, its natural fibrous structure can enhance the toughness of the mixture and improve its crack resistance.

[0076] In addition, the present invention uses pretreated mullite whiskers and magnesium nitrate and zinc nitrate to prepare fillers through a hydrothermal method. When used in combination with rattan bark powder, it can also significantly improve the adhesion between asphalt and aggregate, forming a stronger bonding interface, allowing asphalt to better penetrate into the surface of aggregate and form a tight coating layer, thereby improving the overall strength and wear resistance of the mixture.

[0077] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A long-life asphalt mixture based on the addition of basalt fiber, characterized in that, The composition, by weight, includes 50-60 parts asphalt, 1-5 parts basalt fiber, 450-500 parts aggregate, 10-20 parts filler, and 1-3 parts rattan bark powder; the preparation process of the filler is as follows: (1) Take mullite whiskers for pretreatment; (2) Take a mixed solution of magnesium nitrate and ferric nitrate and add it to a sodium hydroxide solution, stir and mix evenly to obtain a mixed solution; (3) Add the pretreated mullite whiskers from step (1) to the mixture from step (2), stir and mix evenly, and then carry out a hydrothermal reaction to obtain the product. The pretreatment process in step (1) is as follows: Mullite whiskers are added to a mixed solvent and heated, and then the reaction solution is filtered, washed and dried to obtain the product; the mixed solvent is anhydrous ethanol and acetone in a volume ratio of 1:(1-2), and the heating temperature is 75-85℃ for 3-5h.

2. The long-life asphalt mixture based on the addition of basalt fiber according to claim 1, characterized in that, In step (2), the mass ratio of magnesium nitrate, ferric nitrate, sodium hydroxide and water is 1:(0.4-0.8):(0.5-0.9):(45-55).

3. The long-life asphalt mixture based on the addition of basalt fiber according to claim 1, characterized in that, In step (3), the mass ratio of the pretreated mullite whiskers to the magnesium nitrate in the mixture obtained in step (2) is 1:(3-8).

4. The long-life asphalt mixture based on the addition of basalt fiber according to claim 1, characterized in that, In step (3), the temperature of the hydrothermal reaction is 110-120℃ and the time is 24-30h.

5. The long-life asphalt mixture based on the addition of basalt fiber according to claim 1, characterized in that, The mullite whiskers have a diameter of 0.2-3µm and a length of 5-200µm; the aggregate has a particle size of 0.5-2.5mm.

6. The method for preparing long-life asphalt mixture based on the addition of basalt fiber as described in any one of claims 1-5, characterized in that, Includes the following steps: a. Mix the basalt fiber, aggregate, filler, and rattan bark powder evenly according to the above-mentioned weight proportions to obtain a mixture; b. Add the above mixture to the asphalt, heat at 160-170℃ and stir until homogeneous to obtain the final product.

7. The application of the long-life asphalt mixture based on the addition of basalt fiber as described in any one of claims 1-5 in the field of road engineering construction.

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