High oil stone ratio durable basalt fiber asphalt mixture with low temperature crack resistance and preparation method thereof

Abstract

The present application relates to the technical field of asphalt mixture processing, and particularly relates to a high oil-stone ratio durability basalt fiber asphalt mixture with low-temperature crack resistance and a preparation method thereof. The preparation method comprises the following steps: (1) soaking cleaned basalt fiber in a hydrochloric acid solution for pretreatment to obtain pretreated basalt fiber; (2) adding nano-hydroxyapatite, carboxymethyl cellulose and dodecanoic acid into an ethanol aqueous solution for heating reaction, and collecting the product after purification; (3) adding the product into acetone, then adding the pretreated basalt fiber, and stirring to obtain modified basalt fiber; (4) uniformly mixing the modified basalt fiber, asphalt, mineral powder and aggregate according to the weight ratio, and obtaining the high oil-stone ratio durability basalt fiber asphalt mixture with low-temperature crack resistance. The preparation method is simple and easy for large-scale production, and the prepared mixture has excellent low-temperature crack resistance, water stability and high-temperature stability, which is of great significance for improving the quality of road engineering and prolonging the service life.

Description

Technical Field

[0001] This invention relates to the field of asphalt mixture processing technology, and in particular to a high asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance and its preparation method. Background Technology

[0002] With the rapid development of transportation, road construction has also advanced rapidly, leading to a growing demand for high-performance pavement materials. Currently, asphalt pavement is the most widely used road pavement material, possessing high mechanical strength, stability, durability, skid resistance, and surface smoothness. However, during long-term use, it is susceptible to environmental factors and traffic loads, resulting in pavement defects and shortening its service life. Therefore, it is necessary to improve the road performance of asphalt mixtures to extend the service life of asphalt pavements.

[0003] Asphalt mixtures are composite materials mainly composed of asphalt, mineral powder, and aggregates. Their mechanical properties vary depending on the quality and quantity of their constituent materials. Currently, a common method to improve the performance of asphalt mixtures is modification, using materials such as polymers, rubber, and fibers. In practical applications, it has been found that existing asphalt mixtures are prone to cracking and loosening at low temperatures, affecting road service life. Therefore, there is an urgent need to provide a new asphalt mixture to address the problems of cracking and loosening at low temperatures. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, one of the objectives of this invention is to provide a method for preparing a high asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance. This preparation method is simple in steps and easy to mass-produce.

[0005] The second objective of this invention is to provide a high asphalt-aggregate ratio durable basalt fiber asphalt mixture with excellent low-temperature crack resistance, water stability, and high-temperature stability.

[0006] One of the objectives of this invention is achieved through the following technical solution:

[0007] A method for preparing a high-asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance includes the following steps:

[0008] (1) The cleaned basalt fiber was pretreated by immersing it in hydrochloric acid solution to obtain pretreated basalt fiber.

[0009] (2) Nano-hydroxyapatite, carboxymethyl cellulose and dodecanoic acid were added to an aqueous ethanol solution and heated to react. The product was then collected after purification.

[0010] (3) Add the product of step (2) to acetone, then add the pretreated basalt fiber of step (1), and stir to obtain modified basalt fiber.

[0011] (4) Weigh the above modified basalt fiber, asphalt, mineral powder and aggregate according to the weight ratio, and mix them evenly at 140℃-150℃ to obtain the product; the weight ratio is: 1-5 parts of the above modified basalt fiber, 8-15 parts of asphalt, 1-5 parts of mineral powder and 80-90 parts of aggregate.

[0012] Furthermore, the length of the basalt fiber in step (2) is 10-25 mm.

[0013] Furthermore, the mass ratio of nano-hydroxyapatite, carboxymethyl cellulose, and dodecanoic acid in step (2) is 1:(4-8):(2-5).

[0014] Furthermore, the heating reaction in step (2) is carried out at a temperature of 80-90°C for 4-6 hours.

[0015] Furthermore, the concentration of ethanol in the aqueous ethanol solution described in step (2) is 60-75 wt%.

[0016] Further, in step (3), the ratio of the product of step (2), the pretreated basalt fiber of step (1), and acetone is (0.1-0.4)g:(0.3-0.6)g:(90-120)mL.

[0017] Furthermore, the stirring time in step (3) is 20-30 seconds.

[0018] Further, the soaking temperature in step (1) is 30-40℃, and the soaking time is 25-35 min; the concentration of the hydrochloric acid solution is 0.1-0.2 mol / L.

[0019] Further, the aggregate in step (4) consists of a first aggregate with a continuous gradation of 3-5mm and a second aggregate with a continuous gradation of 0-3mm, and the mass ratio of the first aggregate to the second aggregate is 3:2; the mineral powder is limestone powder.

[0020] Furthermore, the limestone powder has a particle size of 2-10 μm.

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

[0022] Furthermore, the mixing temperature in step (4) is 140-150°C.

[0023] The second objective of this invention is achieved by the following technical solution:

[0024] A high-oil-stone-ratio durable basalt fiber asphalt mixture with low-temperature crack resistance was prepared using the above-mentioned preparation method.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] This invention provides a method for preparing a high-asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance. The method involves adding modified basalt fibers to a mixture of asphalt, mineral powder, and aggregates and stirring. The modified basalt fibers are prepared by grafting and modifying the surface of nano-hydroxyapatite before introducing it onto the surface of the basalt fibers. This modification method alters the surface of the basalt fibers, enhancing the interaction between the basalt fibers and the asphalt and aggregates. This interaction not only allows the asphalt mixture to better resist the formation and propagation of cracks caused by temperature stress under low-temperature conditions, improving its low-temperature crack resistance, but also effectively disperses and transfers stress within the asphalt mixture, thereby improving its high-temperature stability. Furthermore, this modification method enhances the bonding performance between the basalt fibers and the asphalt and aggregates, resulting in a denser and more stable structure, reducing the erosive and destructive effects of moisture on the asphalt mixture.

[0027] The method for preparing high asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance provided by this invention is simple and easy to mass-produce.

[0028] The high asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance provided by this invention has excellent low-temperature crack resistance, water stability and high-temperature stability, which is of great significance for improving the quality of road engineering and extending the service life of roads. Detailed Implementation

[0029] The present invention will be further described below with reference to 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.

[0030] In this invention, the length of the basalt fiber is 10-25mm; the asphalt is No. 70 Grade A asphalt; the particle size of the limestone powder is 2-10μm; the aggregate consists of a first aggregate with a continuous gradation of 3-5mm and a second aggregate with a continuous gradation of 0-3mm, and the mass ratio of the first aggregate to the second aggregate is 3:2.

[0031] Example

[0032] Example 1

[0033] This embodiment provides a method for preparing a high-oil-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance, as detailed below:

[0034] (1) Immerse the basalt fiber in a beaker containing ethanol for 3 hours to remove impurities from the surface of the basalt fiber. After taking it out, immerse it in a 0.2 mol / L hydrochloric acid solution at 35°C for 30 minutes. After immersion, wash the basalt with water until the pH of the washing solution is 7. After drying, obtain the pretreated basalt fiber.

[0035] (2) According to the mass ratio of nano-hydroxyapatite, carboxymethyl cellulose and dodecanoic acid 1:6:4, nano-hydroxyapatite, carboxymethyl cellulose and dodecanoic acid were added to an ethanol aqueous solution (70wt%), heated at 85℃ for 5h, the solid was collected by centrifugation and washed with water, and the product was collected after drying at 55℃ for 6h.

[0036] (3) According to the ratio of the product of step (2), the pretreated basalt fiber of step (1), and acetone of 0.2g:0.5g:100mL, add the product of step (2) to acetone, then add the pretreated basalt fiber of step (1), stir at room temperature for 25s to obtain modified basalt fiber.

[0037] (4) Weigh each raw material according to the weight ratio, and mix 3 parts modified basalt fiber, 12 parts No. 70 Grade A asphalt, 4 parts limestone powder and 85 parts aggregate at 145℃ to obtain the final product.

[0038] This embodiment also provides a high asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance, which is prepared by the above preparation method.

[0039] Example 2

[0040] This embodiment provides a method for preparing a high-oil-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance, as detailed below:

[0041] (1) Immerse the basalt fiber in a beaker containing ethanol for 3 hours to remove impurities from the surface of the basalt fiber. After taking it out, immerse it in a 0.1 mol / L hydrochloric acid solution at 30°C for 35 minutes. After immersion, wash the basalt with water until the pH of the washing solution is 7. After drying, obtain the pretreated basalt fiber.

[0042] (2) According to the mass ratio of nano-hydroxyapatite, carboxymethyl cellulose and dodecanoic acid 1:4:2, nano-hydroxyapatite, carboxymethyl cellulose and dodecanoic acid were added to an ethanol aqueous solution (60wt%), heated at 80℃ for 6h, the solid was collected by centrifugation and washed with water, and the product was collected after drying at 55℃ for 6h.

[0043] (3) According to the ratio of the product of step (2), the pretreated basalt fiber of step (1), and acetone of 0.1g:0.3g:90mL, add the product of step (2) to acetone, then add the pretreated basalt fiber of step (1), stir at room temperature for 20s to obtain modified basalt fiber.

[0044] (4) Weigh each raw material according to the weight ratio, and mix 1 part modified basalt fiber, 8 parts No. 70 Grade A asphalt, 1 part limestone and 80 parts aggregate at 140℃ to obtain the final product.

[0045] This embodiment also provides a high asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance, which is prepared by the above preparation method.

[0046] Example 3

[0047] This embodiment provides a method for preparing a high-oil-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance, as detailed below:

[0048] (1) Immerse the basalt fiber in a beaker containing ethanol for 3 hours to remove impurities from the surface of the basalt fiber. After taking it out, immerse it in a 0.2 mol / L hydrochloric acid solution at 40°C for 25 minutes. After immersion, wash the basalt with water until the pH of the washing solution is 7. After drying, obtain the pretreated basalt fiber.

[0049] (2) According to the mass ratio of nano-hydroxyapatite, carboxymethyl cellulose and dodecanoic acid 1:8:5, nano-hydroxyapatite, carboxymethyl cellulose and dodecanoic acid were added to an ethanol aqueous solution (75wt%), heated at 90℃ for 4h, the solid was collected by centrifugation and washed with water, and the product was collected after drying at 55℃ for 6h.

[0050] (3) According to the ratio of the product of step (2), the pretreated basalt fiber of step (1), and acetone of 0.4g:0.6g:120mL, add the product of step (2) to acetone, then add the pretreated basalt fiber of step (1), stir at room temperature for 30s to obtain modified basalt fiber.

[0051] (4) Weigh each raw material according to the weight ratio, and mix 5 parts modified basalt fiber, 15 parts No. 70 Grade A asphalt, 5 parts limestone and 90 parts aggregate at 150℃ to obtain the final product.

[0052] This embodiment also provides a high asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance, which is prepared by the above preparation method.

[0053] Comparative Example

[0054] Comparative Example 1

[0055] This comparative example provides a method for preparing basalt fiber asphalt mixture, as detailed below:

[0056] Weigh each raw material according to the weight ratio, and mix 3 parts basalt fiber, 12 parts No. 70 Grade A asphalt, 4 parts limestone powder, and 85 parts aggregate at 145℃ until uniform.

[0057] This comparative example also provides a basalt fiber asphalt mixture, which is prepared using the above-described preparation method.

[0058] Comparative Example 2

[0059] This comparative example provides a method for preparing basalt fiber asphalt mixture, as detailed below:

[0060] Weigh each raw material according to the weight ratio, and mix 3 parts of a mixture consisting of basalt fiber, nano-hydroxyapatite and carboxymethyl cellulose, 12 parts of No. 70 Grade A asphalt, 4 parts of limestone powder and 85 parts of aggregate at 145°C until uniform. The amount of basalt fiber used is the same as that of the pretreated basalt fiber in Example 1, and the mass of nano-hydroxyapatite and carboxymethyl cellulose is the same as that in Example 1.

[0061] This comparative example also provides a basalt fiber asphalt mixture, which is prepared using the above-described preparation method.

[0062] Performance testing

[0063] According to JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering", the low-temperature crack resistance, freeze-thaw splitting strength ratio, water immersion residual stability, Marshall stability, and dynamic stability of the mixtures in Examples 1-3 and Comparative Examples 1-2 of this invention were tested. The test results are shown in Table 1.

[0064] Table 1

[0065]

[0066] The performance test results above show that: (1) the maximum bending strain data indicates that the low-temperature crack resistance of the mixtures obtained in Examples 1-3 of this invention is effectively improved; (2) the freeze-thaw splitting strength ratio and water immersion residual stability data indicate that the water stability of the mixtures obtained in Examples 1-3 of this invention is effectively improved; (3) the Marshall stability and dynamic stability data indicate that the high-temperature stability of the mixtures obtained in Examples 1-3 of this invention is effectively improved. The enhancement of the above properties is beneficial to increasing the durability of the mixtures. In summary, the mixtures obtained in Examples 1-3 of this invention have excellent comprehensive performance.

[0067] Compared to Examples 1-3, the properties of the mixtures in Comparative Examples 1-2 were reduced. Analysis revealed that Comparative Example 1 used basalt fiber instead of modified basalt fiber; Comparative Example 2 used a mixture of basalt fiber, nano-hydroxyapatite, and carboxymethyl cellulose instead of modified basalt fiber. Further analysis showed that the modified basalt fiber of this invention was prepared by grafting modification of the nano-hydroxyapatite surface before introducing it onto the basalt fiber surface. This modification method alters the surface of the basalt fiber, enhancing the interaction force between the basalt fiber and the asphalt and aggregates. This interaction force not only allows the asphalt mixture to better resist the formation and propagation of cracks caused by temperature stress under low-temperature conditions, improving the low-temperature crack resistance of the asphalt mixture, but also effectively disperses and transfers stress in the asphalt mixture, thereby improving the high-temperature stability of the asphalt mixture. Furthermore, the modification method also enhances the bonding performance between the basalt fiber and the asphalt and aggregates, resulting in a denser and more stable structure, reducing the erosive and destructive effects of moisture on the asphalt mixture.

[0068] In summary, applying the modified basalt fiber of this invention to the preparation of asphalt mixtures can significantly improve the low-temperature crack resistance, water stability, and high-temperature stability of asphalt mixtures, which is of great significance for improving the quality of road engineering and extending service life.

[0069] 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 method for preparing a high-asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance, characterized in that, Includes the following steps: (1) The cleaned basalt fiber was pretreated by immersing it in hydrochloric acid solution to obtain pretreated basalt fiber. (2) Nano-hydroxyapatite, carboxymethyl cellulose and dodecanoic acid were added to an aqueous ethanol solution and heated to react. The product was then collected after purification. (3) Add the product of step (2) to acetone, then add the pretreated basalt fiber of step (1), and stir to obtain modified basalt fiber. (4) Mix the modified basalt fiber, asphalt, mineral powder and aggregate evenly according to the weight ratio to obtain the product; the weight ratio is: 1-5 parts of the modified basalt fiber, 8-15 parts of asphalt, 1-5 parts of mineral powder and 80-90 parts of aggregate.

2. The method for preparing high asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance according to claim 1, characterized in that, The mass ratio of nano-hydroxyapatite, carboxymethyl cellulose, and dodecanoic acid in step (2) is 1:(4-8):(2-5).

3. The method for preparing high-asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance according to claim 1, characterized in that, The heating reaction in step (2) is carried out at a temperature of 80-90℃ for 4-6 hours.

4. The method for preparing high asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance according to claim 1, characterized in that, The concentration of ethanol in the aqueous ethanol solution described in step (2) is 60-75 wt%.

5. The method for preparing high-asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance according to claim 1, characterized in that, The ratio of the product of step (2), the pretreated basalt fiber of step (1), and acetone in step (3) is (0.1-0.4)g:(0.3-0.6)g:(90-120)mL.

6. The method for preparing high asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance according to claim 1, characterized in that, The stirring time in step (3) is 20-30 seconds.

7. The method for preparing high asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance according to claim 1, characterized in that, The soaking temperature in step (1) is 30-40℃, and the soaking time is 25-35 min; the concentration of the hydrochloric acid solution is 0.1-0.2 mol / L.

8. The method for preparing high-asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance according to claim 1, characterized in that, The aggregate in step (4) consists of a first aggregate with a continuous gradation of 3-5mm and a second aggregate with a continuous gradation of 0-3mm, with a mass ratio of 3:2 between the first aggregate and the second aggregate; the mineral powder is limestone powder.

9. The method for preparing high-asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance according to claim 1, characterized in that, The mixing temperature in step (4) is 140-150℃.

10. A high-asphalt-aggregate ratio durable basalt fiber asphalt mixture with low-temperature crack resistance, characterized in that, It is prepared by the preparation method according to any one of claims 1-9.

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