Pe basalt fiber composite modified asphalt mixture and preparation method therefor

Abstract

The present application relates to the technical field of basalt fibers, and in particular to a polyethylene (PE) basalt fiber composite modified asphalt mixture and a preparation method therefor. The preparation method for the PE basalt fiber composite modified asphalt mixture comprises the following steps: immersing basalt fibers into a complexing agent, adding a granulating agent, and carrying out hydrothermal reaction to obtain a PE basalt fiber particle composite material; and mixing the PE basalt fiber particle composite material with an asphalt mixture to obtain the PE basalt fiber composite modified asphalt mixture. In the present application, asphalt is modified with PE, and PE basalt fiber particles are prepared from PE and basalt fibers as base materials under the action of the granulating agent; the PE basalt fiber particles are blended with a mineral aggregate at 170-180°C; the PE is uniformly melted and then blended with asphalt; a PE film permeates into the asphalt to improve the performance of the asphalt between aggregates; and the PE having undergone aggregate friction covers the surface of the aggregates to modify the asphalt.

Description

A PE basalt fiber composite modified asphalt mixture and preparation method Technical Field

[0001] The present application belongs to the technical field of basalt fibers, and specifically relates to a PE basalt fiber composite modified asphalt mixture and a preparation method thereof. Background Art

[0002] Asphalt mixture is one of the most widely used road construction materials. It is mainly composed of mineral aggregate, asphalt, and admixtures, and has certain properties such as high-temperature rutting resistance, low-temperature cracking resistance, and water damage resistance. However, in actual use, the performance of asphalt mixture is greatly affected by temperature, traffic volume, and vehicle axle load. In high-temperature environments, it is prone to plastic deformation under axle load, especially heavy axle load, resulting in rutting. In low-temperature environments, it will produce thermal shrinkage stress. When the allowable tensile stress within the asphalt pavement structure layer is less than the thermal shrinkage stress, cracking will occur, forming cracks. Asphalt pavement gradually ages under the combined effects of external factors such as sunlight, vehicle axle load, and dynamic water pressure. The adhesion between the aged asphalt and the mineral aggregate decreases, and the asphalt mortar easily peels off from between the mineral aggregate, resulting in loose asphalt pavement, potholes, and other defects.

[0003] In order to solve the above technical problems, researchers in this field have proposed to modify the asphalt mixture by introducing modifiers to improve the durability of asphalt pavement, such as using asphalt stabilizers such as basalt fiber for improvement.

[0004] Patent publication number CN105885391A discloses a novel basalt fiber asphalt mixture modifier and preparation method. The modifier is made from basalt fiber and a high-adhesion impregnant. The preparation method comprises mixing film former A, film former B, an antistatic agent, a coupling agent, a lubricant, and modified nano-SiO2, and then impregnating, coating, and chopping the basalt fiber. The existing basalt fiber asphalt mixture production process is prone to problems such as inconvenient chopped basalt fiber addition, difficulty in measuring the amount of chopped basalt fiber added, and difficulty in determining the timing of addition. This can result in excessive or insufficient basalt fiber addition. Furthermore, due to untimely addition, the basalt fiber and mineral material do not mix well enough, making it difficult to disperse into bundles. Ultimately, the performance of the basalt fiber asphalt mixture fails to meet expectations.

[0005] Summary of the Invention

[0006] The purpose of the present application is to provide a PE basalt fiber composite modified asphalt mixture, which has strong water damage resistance and good stress resistance.

[0007] Another object of the present application is to provide a method for preparing a PE basalt fiber composite modified asphalt mixture.

[0008] In order to achieve the above objectives, the technical solution adopted in this application is: a method for preparing a PE basalt fiber composite modified asphalt mixture, comprising the following steps:

[0009] 1) After immersing basalt fiber in a complexing agent, a granulating agent is added, and a PE basalt fiber particle composite material is obtained through a hydrothermal reaction;

[0010] 2) Mixing the PE basalt fiber particle composite material with asphalt mixture to obtain a PE basalt fiber composite modified asphalt mixture.

[0011] Furthermore, the asphalt mixture described in step 2) includes mineral material and asphalt, and the mineral material includes mineral powder and aggregate; in the asphalt mixture, the weight ratio of aggregate, mineral powder and asphalt is 930±10:20±1:50±2, preferably 930:20:50.

[0012] Furthermore, in step 2), the PE basalt fiber particle composite material and the asphalt mixture are mixed by heating the aggregate, dry-mixing the PE basalt fiber particle composite material and the heated aggregate for 10 to 15 seconds, then adding asphalt and wet-mixing for 3 to 5 seconds, and finally adding mineral powder and mixing for 4 to 5 seconds.

[0013] Furthermore, the complexing agent in step 1) is polyethylene, and the preparation method of the PE basalt fiber particle composite material is to immerse basalt fiber in a polyethylene melt, then add a granulating agent, and obtain it through a hydrothermal reaction; the polyethylene melt is obtained by melting polyethylene at a temperature of 140-150°C.

[0014] Furthermore, the granulating agent in step 1) is matrix asphalt.

[0015] Furthermore, the preparation method of the basalt fiber is to crush a single natural basalt ore, heat it to 1450-1500°C to form a basalt molten glass state, and then pass it through a platinum-rhodium alloy bushing for high-speed drawing and surface treatment to prepare a continuous fiber. The single fiber diameter of the basalt fiber is 13-21 μm and the density is greater than 2.7 g / cm 3 .

[0016] Furthermore, the PE basalt fiber composite modified asphalt mixture comprises 3 to 5 parts by weight of basalt fiber, 3 to 4 parts by weight of complexing agent, 1 to 2 parts by weight of granulating agent and 1000 parts by weight of asphalt mixture.

[0017] Furthermore, the weight ratio of the PE basalt fiber particle composite material to the asphalt mixture is 6 to 9:1000.

[0018] A PE basalt fiber composite modified asphalt mixture is prepared by the above method.

[0019] Beneficial effects of this application:

[0020] The present application uses polyethylene (PE) to modify asphalt. Under the action of a granulating agent, PE basalt fiber particles are prepared using PE and basalt fiber as the base material. The PE basalt fiber particle composite material is mixed with mineral material at 170-180°C. The polyethylene is evenly melted and then mixed with asphalt. The polyethylene film penetrates into the asphalt to improve the performance of the aggregate and asphalt. After friction with the aggregate, the PE is coated on the surface of the aggregate to modify the asphalt.

[0021] By observing the internal and external morphology of the PE basalt fiber composite modified asphalt mixture structure of the present application with a scanning electron microscope, it was found that the bundled dispersed basalt fibers were in a chaotic distribution state in the asphalt mixture. The basalt fibers were interconnected with the asphalt and aggregate to form a good fiber network structure. This fiber network structure makes the asphalt mixture more compact and more connected. As can be seen from Table 1, this fiber network structure can enhance the stress-bearing properties of the asphalt mixture, inhibit crack expansion in a bridging manner, and extend fatigue life. Chemical cross-linking and physical entanglement occur between PE and basalt fibers and asphalt, which play a coupling role. The internal components of the asphalt mixture are more tightly cross-linked, which improves the deformation capacity of the asphalt and the adhesion between the asphalt and the aggregate, thereby improving the water damage resistance of the PE basalt fiber composite modified asphalt mixture.

[0022] The granulating agent of the present application uses matrix asphalt, which brings the polar groups or chain links at the two interfaces closer to each other through molecular forces such as van der Waals attraction and hydrogen bonding. During this process, increasing the temperature, applying contact pressure and reducing the viscosity of the adhesive are all conducive to the mutual attraction between the interface molecules, so that the distance between the molecules is further shortened to the maximum stable state. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a scanning electron microscope image of the interior of the PE basalt fiber composite modified asphalt mixture of Example 1;

[0024] FIG2 is an enlarged view of the interior of the PE basalt fiber composite modified asphalt mixture of Example 1;

[0025] FIG3 is a physical picture of the asphalt mixture of Comparative Example 1;

[0026] FIG4 is a physical picture of the PE modified asphalt mixture of Comparative Example 2;

[0027] FIG5 is a physical picture of the basalt fiber asphalt mixture of Comparative Example 3. DETAILED DESCRIPTION

[0028] The technical solution of the present application will be further described below with reference to embodiments and drawings.

[0029] Example 1

[0030] The preparation method of the PE basalt fiber composite modified asphalt mixture of this embodiment is as follows:

[0031] 1) Preparation of PE Basalt Fiber Particle Composite Material: Natural basalt ore is crushed and heated to 1500°C to form a molten basalt glass. Basalt fiber is then rapidly drawn through a platinum-rhodium alloy drawing plate. Three parts of PE are weighed as a complexing agent and heated to 140°C to form a melt. Three parts of basalt fiber are immersed in the PE melt, and one part of matrix asphalt is added. A hydrothermal reaction is carried out at 150°C. After chemical or mechanical processing, the PE basalt fiber particle composite material with a diameter of 4 mm and a length of 6 mm is produced.

[0032] 2) Heating: Weigh 930 parts of aggregate and heat to 180°C.

[0033] 3) Mixing: Weigh 6 parts of PE basalt fiber particle composite material and 930 parts of 180°C aggregate and dry mix them for 10 seconds to fully melt the PE and disperse the basalt fibers into bundles. Add 50 parts of 165°C No. 70 Grade A road petroleum asphalt and wet mix them for 3 seconds. Then add 20 parts of mineral powder and mix them for 5 seconds to obtain a PE basalt fiber composite modified asphalt mixture with uniformly dispersed basalt fiber bundles.

[0034] Example 2

[0035] The preparation method of the PE basalt fiber composite modified asphalt mixture of this embodiment is as follows:

[0036] 1) Preparation of PE Basalt Fiber Particle Composite Material: Natural basalt ore is crushed and heated to 1500°C to form a molten basalt glass. Basalt fiber is then rapidly drawn through a platinum-rhodium alloy drawing plate. Three parts of PE are weighed as a complexing agent and heated to 140°C to form a melt. Four parts of basalt fiber are immersed in this PE melt. One part of matrix asphalt is added and a hydrothermal reaction is carried out at 150°C. After chemical or mechanical processing, PE basalt fiber particle composite materials with a diameter of 4 mm and a length of 6 mm are produced.

[0037] 2) Heating: Weigh 930 parts of aggregate and heat to 180°C.

[0038] 3) Mixing: Weigh 7 parts of PE basalt fiber particle composite material and 930 parts of 180°C aggregate and dry mix them for 10 seconds to fully melt the PE and fully disperse the basalt fibers into bundles. Add 50 parts of 165°C No. 70 Grade A road petroleum asphalt and wet mix them for 3 seconds. Then add 20 parts of mineral powder and mix for 5 seconds to obtain a PE basalt fiber composite modified asphalt mixture with uniformly dispersed basalt fiber bundles.

[0039] Example 3

[0040] The preparation method of the PE basalt fiber composite modified asphalt mixture of this embodiment is as follows:

[0041] 1) Preparation of PE Basalt Fiber Particle Composite: Natural basalt ore is crushed and heated to 1500°C to form a molten glassy basalt. Basalt fiber is then rapidly drawn through a platinum-rhodium alloy drawing plate. Three parts of PE are weighed as a complexing agent and heated to 140°C to form a melt. Five parts of basalt fiber are immersed in this PE melt. Two parts of matrix asphalt are added and a hydrothermal reaction is carried out at 150°C. After chemical or mechanical processing, PE basalt fiber particle composites with a diameter of 4 mm and a length of 6 mm are produced.

[0042] 2) Heating: Weigh 930 parts of aggregate and heat to 180°C.

[0043] 3) Mixing: Weigh 8 parts of PE basalt fiber particle composite material and 930 parts of 180°C aggregate and dry mix them for 10 seconds to fully melt the PE and fully disperse the basalt fibers into bundles. Add 50 parts of 165°C No. 70 Grade A road petroleum asphalt and wet mix them for 3 seconds. Then add 20 parts of mineral powder and mix them for 5 seconds to finally obtain a PE basalt fiber composite modified asphalt mixture with uniformly dispersed basalt fiber bundles.

[0044] Example 4

[0045] The preparation method of the PE basalt fiber composite modified asphalt mixture of this embodiment is as follows:

[0046] 1) Preparation of PE Basalt Fiber Particle Composite: Natural basalt ore is crushed and heated to 1500°C to form a molten glassy basalt. Basalt fiber is then rapidly drawn through a platinum-rhodium alloy drawing plate. Four parts of PE are weighed as a complexing agent and heated to 140°C to form a melt. Three parts of basalt fiber are immersed in this PE melt. One part of matrix asphalt is added and a hydrothermal reaction is carried out at 150°C. After chemical or mechanical processing, PE basalt fiber particle composites with a diameter of 4 mm and a length of 6 mm are produced.

[0047] 2) Heating: Weigh 930 parts of aggregate and heat to 180°C.

[0048] 3) Mixing: Weigh 7 parts of PE basalt fiber particle composite material and 930 parts of 180°C aggregate and dry mix them for 10 seconds to fully melt the PE and fully disperse the basalt fibers into bundles. Add 50 parts of 165°C No. 70 Grade A road petroleum asphalt and wet mix them for 3 seconds. Then add 20 parts of mineral powder and mix for 5 seconds to obtain a PE basalt fiber composite modified asphalt mixture with uniformly dispersed basalt fiber bundles.

[0049] Example 5

[0050] The preparation method of the PE basalt fiber composite modified asphalt mixture of this embodiment is as follows:

[0051] 1) Preparation of PE Basalt Fiber Particle Composite: Natural basalt ore is crushed and heated to 1500°C to form a molten glassy basalt. Basalt fiber is then rapidly drawn through a platinum-rhodium alloy drawing plate. Four parts of PE are weighed as a complexing agent and heated to 140°C to form a melt. Three parts of basalt fiber are immersed in this PE melt. One part of matrix asphalt is added and a hydrothermal reaction is carried out at 150°C. After chemical or mechanical processing, PE basalt fiber particle composites with a diameter of 4 mm and a length of 6 mm are produced.

[0052] 2) Heating: Weigh 930 parts of aggregate and heat to 180°C.

[0053] 3) Mixing: Weigh 8 parts of PE basalt fiber particle composite material and 930 parts of 180°C aggregate and dry mix them for 10 seconds to fully melt the PE and fully disperse the basalt fibers into bundles. Add 50 parts of 165°C No. 70 Grade A road petroleum asphalt and wet mix them for 3 seconds. Then add 20 parts of mineral powder and mix for 5 seconds to obtain a PE basalt fiber composite modified asphalt mixture with uniformly dispersed basalt fiber bundles.

[0054] Example 6

[0055] The preparation method of the PE basalt fiber composite modified asphalt mixture of this embodiment is as follows:

[0056] 1) Preparation of PE Basalt Fiber Particle Composite Material: Natural basalt ore is crushed and heated to 1500°C to form a molten glassy basalt. Basalt fiber is then rapidly drawn through a platinum-rhodium alloy drawing plate. Four parts of PE are weighed as a complexing agent and heated to 140°C to form a melt. Five parts of basalt fiber are immersed in this PE melt. Two parts of matrix asphalt are added and a hydrothermal reaction is carried out at 150°C. After chemical or mechanical processing, PE basalt fiber particle composite materials with a diameter of 4 mm and a length of 6 mm are produced.

[0057] 2) Heating: Weigh 930 parts of aggregate and heat to 180°C.

[0058] 3) Mixing: Weigh 9 parts of PE basalt fiber particle composite material and 930 parts of 180°C aggregate and dry mix them for 10 seconds to fully melt the PE and fully disperse the basalt fibers into bundles. Add 50 parts of 165°C No. 70 Grade A road petroleum asphalt and wet mix them for 3 seconds. Then add 20 parts of mineral powder and mix them for 5 seconds to obtain a PE basalt fiber composite modified asphalt mixture with uniformly dispersed basalt fiber bundles.

[0059] PE basalt fiber particle composite materials can be placed in either automated or manual ways. Automated placement should be used for larger projects, while manual placement is preferred for smaller ones. Automated placement should be equipped with a weighing device for PE basalt fiber particle composite materials, with a weighing error controlled within ±5%. When using manual placement, PE basalt fiber particle composite materials should be packaged in bags based on the required quantity per batch of the mixing station to facilitate metered placement. During placement, information prompts such as whistles or flashing lights, as well as metering monitoring devices, should be provided to ensure that PE basalt fiber particle composite materials are not missed or overdosed. PE basalt fiber particle composite materials should be added according to the designed proportion after the hot aggregate mixing begins. The mixing time for PE basalt fiber particle composite modified asphalt mixtures should be determined based on the mechanical equipment and through trial mixes. The mix should be uniform, with all aggregate particles fully coated with the asphalt binder and no white material present. The dry mix time after adding the PE basalt fiber particle composite materials should be no less than 6 seconds, and the overall dry mix time should be 10-15 seconds.

[0060] Comparative Example 1

[0061] This comparative example uses asphalt mixture.

[0062] Comparative Example 2

[0063] Polyethylene modified asphalt mixture was used. The specific method was as follows: 930 parts of aggregate were weighed and heated to 180°C, 3 parts of PE were weighed and dry-mixed with 930 parts of 180°C aggregate for 10 seconds to fully melt the PE, 50 parts of 70#A grade road petroleum asphalt at 165°C were added, wet-mixed for 3 seconds, and 20 parts of mineral powder were added and mixed for 5 seconds to finally obtain the PE modified asphalt mixture.

[0064] Comparative Example 3

[0065] Basalt fiber modified asphalt mixture is used. The specific method is as follows: 930 parts of aggregate are weighed and heated to 175°C, 4 parts of basalt fiber are weighed and dry-mixed with 930 parts of 175°C aggregate for 10 seconds to allow the basalt fiber to be fully dispersed into bundles, 50 parts of 165°C No. 70 Grade A road petroleum asphalt are added, wet-mixed for 3 seconds, and then 20 parts of mineral powder are added and mixed for 5 seconds to finally obtain basalt fiber asphalt mixture.

[0066] Experimental Example 1

[0067] The present application compares the performance test results of Examples 1 to 3 and Comparative Examples 1 to 3, and the test results are shown in Table 1.

[0068] Table 1 Comparison of performance test results

[0069] As shown in the test results in Table 1, the dynamic stability of the asphalt mixtures of Examples 1-3 is significantly higher than that of the asphalt mixtures of Comparative Examples 1-3, indicating that the high-temperature rutting resistance of the asphalt mixtures of Examples 1-3 is significantly better than that of the asphalt mixtures of Comparative Examples 1-3. The residual stability and residual strength ratio of the asphalt mixtures of Examples 1-3 are higher than those of the asphalt mixtures of Comparative Examples 1-3, indicating that the asphalt mixtures of Examples 1-3 have stronger resistance to water damage. The flexural failure strain values ​​of the asphalt mixtures of Examples 1-3 are higher than those of the asphalt mixtures of Comparative Examples 1-3, indicating that the asphalt mixtures of Examples 1-3 have stronger low-temperature crack resistance. The high-temperature stability and low-temperature crack resistance of Example 2 are improved by 220.3% and 51.8%, respectively, compared with Comparative Example 1. The residual stability and residual strength of Example 3 are improved by 10.8% and 15.1%, respectively, compared with Comparative Example 1.

Claims

1. A preparation method of a PE basalt fiber composite modified asphalt mixture, characterized in that It includes the following steps: 1) After immersing basalt fibers in a complexing agent, a granulating agent is added, and through hydrothermal reaction, a PE basalt fiber particle composite material is obtained; the complexing agent is polyethylene; 2) The PE basalt fiber particle composite material is mixed with an asphalt mixture to obtain a PE basalt fiber composite modified asphalt mixture.

2. The preparation method of the PE basalt fiber composite modified asphalt mixture according to claim 1, characterized in that, In step 2), the asphalt mixture includes mineral materials and asphalt, and the mineral materials include mineral powder and aggregates; in the asphalt mixture, the weight ratio of aggregates, mineral powder, and asphalt is 930±10:20±1:50±2.

3. The preparation method of the PE basalt fiber composite modified asphalt mixture according to claim 2, characterized in that, In the asphalt mixture, the weight ratio of aggregates, mineral powder, and asphalt is 930:20:

50.

4. The preparation method of the PE basalt fiber composite modified asphalt mixture according to claim 2, characterized in that, The mixing of the PE basalt fiber particle composite material and the asphalt mixture in step 2) includes: after heating the aggregates, the PE basalt fiber particle composite material and the heated aggregates are dry-mixed for 10 - 15 s, then asphalt is added for wet mixing for 3 - 5 s, and finally mineral powder is added for mixing for 4 - 5 s.

5. The preparation method of the PE basalt fiber composite modified asphalt mixture according to claim 4, characterized in that, The heating temperature of the aggregates is 170 - 180 °C.

6. The preparation method of the PE basalt fiber composite modified asphalt mixture according to claim 4, characterized in that, The PE basalt fiber particle composite material is put in after the heated aggregates start to be mixed, and the dry mixing time after adding the PE basalt fiber particle composite material is not less than 6 s, and the overall dry mixing time is 10 - 15 s.

7. The preparation method of the PE basalt fiber composite modified asphalt mixture according to claim 4, characterized in that, The temperature of the asphalt is 165 °C, and the asphalt is 70# A-grade road petroleum asphalt.

8. The preparation method of the PE basalt fiber composite modified asphalt mixture according to claim 1, characterized in that, The preparation method of the PE basalt fiber particle composite material in step 1) includes: after immersing basalt fibers in a polyethylene melt, a granulating agent is added, and through hydrothermal reaction, a PE basalt fiber particle composite material is obtained; the polyethylene melt is prepared by melting polyethylene at a temperature of 140 - 150 °C.

9. The preparation method of the PE basalt fiber composite modified asphalt mixture according to claim 1, characterized in that, The temperature of the hydrothermal reaction is 150 °C.

10. The preparation method of the PE basalt fiber composite modified asphalt mixture according to claim 1 or 8, characterized in that, The granulating agent in step 1) is matrix asphalt.

11. The preparation method of the PE basalt fiber composite modified asphalt mixture according to claim 1 or 8, characterized in that, The preparation method of the basalt fibers includes: after crushing natural basalt single ore, it is heated to 1450 - 1500 °C to form a basalt molten glass state, and then high-speed wire drawing and surface treatment are carried out through a platinum-rhodium alloy spinneret.

12. The preparation method of the PE basalt fiber composite modified asphalt mixture according to claim 1, characterized in that, After the hydrothermal reaction, it also includes chemically or mechanically processing the obtained product.

13. The preparation method of the PE basalt fiber composite modified asphalt mixture according to claim 1 or 12, characterized in that, The diameter of the PE basalt fiber particle composite material is 4 mm, and the length is 6 mm.

14. The preparation method of the PE basalt fiber composite modified asphalt mixture according to claim 1, characterized in that, In the PE basalt fiber composite modified asphalt mixture, the weight parts of basalt fibers are 3 - 5 parts, the weight parts of the complexing agent are 3 - 4 parts, the weight parts of the granulating agent are 1 - 2 parts, and the weight parts of the asphalt mixture are 1000 parts.

15. The preparation method of the PE basalt fiber composite modified asphalt mixture according to claim 1, characterized in that, The weight ratio of the PE basalt fiber particle composite material to the asphalt mixture is 6 - 9:1000.

16. A PE basalt fiber composite modified asphalt mixture, characterized in that, It is prepared by using the preparation method described in any one of claims 1 - 15; the PE basalt fiber composite modified asphalt mixture includes an asphalt mixture and a PE basalt fiber particle composite material.

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