Asphalt mixture and preparation method thereof

Abstract

The invention relates to the technical field of asphalt, and provides an asphalt mixture and a preparation method thereof. The asphalt mixture comprises the following components in parts by mass: 5-10 parts of asphalt, 60-70 parts of coarse aggregate, 15-25 parts of fine aggregate, 0.2-0.5 part of fiber filler and 8-12 parts of granular filler, and the granular filler is coal ash coated mineral powder. According to the technical scheme, the problems of poor high-temperature stability and low-temperature crack resistance of the asphalt mixture in related technologies are solved.

Description

Technical Field

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

[0002] Asphalt mixture is a general term for a mixture of asphalt and mineral materials, among which mineral materials include coarse aggregate, fine aggregate and filler. Coarse aggregate and fine aggregate play the role of skeleton, while asphalt and filler play the role of cementation and filling. After the asphalt mixture is spread and compacted into shape, it becomes an asphalt pavement. Compared with cement concrete pavement, asphalt pavement has the advantages of smooth surface, no joints, comfortable driving, wear resistance, low vibration, low noise, short construction period, simple maintenance and repair, and suitable for phased construction, so it has been widely used. However, asphalt mixture also has the problem of insufficient high temperature stability and low temperature crack resistance. Summary of the invention

[0003] The invention provides an asphalt mixture and a preparation method thereof, which solves the problems of poor high-temperature stability and low-temperature crack resistance of the asphalt mixture in the related art.

[0004] The technical solution of the present invention is as follows: An asphalt mixture comprises the following components in parts by weight: 5-10 parts of asphalt, 60-70 parts of coarse aggregate, 15-25 parts of fine aggregate, 0.2-0.5 parts of fiber filler, and 8-12 parts of granular filler, wherein the granular filler is fly ash-coated mineral powder.

[0005] As a further technical solution, the preparation method of the granular filler includes the following steps: mixing mineral powder and fly ash, and grinding to obtain a granular filler.

[0006] As a further technical solution, the raw materials of the granular filler include fly ash and mineral powder in a mass ratio of 1 to 3:20.

[0007] As a further technical solution, the granular filler includes a first modified granular filler and / or a second modified granular filler, the modifier of the first modified granular filler is siloxane, and the modifier of the second modified granular filler is a diol compound.

[0008] The present invention uses siloxane-modified granular fillers and / or diol compound-modified granular fillers. After the granular fillers are modified by siloxane and / or diol compounds, the inorganic property on the surface of the granular fillers is converted into organic property, and the granular fillers also have atoms that can form hydrogen bonds with asphalt. The formation of hydrogen bonds helps to improve the compatibility of asphalt and granular fillers, thereby further improving the high temperature stability and low temperature crack resistance of the asphalt mixture.

[0009] The siloxane in the present invention may be any one or more siloxanes, for example, it may be one or more of aminosiloxane, vinylsiloxane, epoxysiloxane, and mercaptosiloxane. The aminosiloxane may be, for example, 3-aminopropyltriethoxysilane, the vinylsiloxane may be, for example, vinyltri(β-methoxyethoxy)silane, and the epoxysiloxane may be, for example, γ-glycidyloxypropyltrimethoxysilane.

[0010] As a further technical solution, the siloxane is mercaptosiloxane.

[0011] The inventors have found that when mercaptosiloxane-modified granular filler is used as the first modified granular filler, the high temperature stability and low temperature crack resistance of the asphalt mixture are further improved.

[0012] The mercaptosiloxane in the present invention can be any one or more siloxanes containing a mercapto group, for example, it can be one or more of mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, mercaptopropylmethyldimethoxysilane, (mercaptomethyl)triethoxysilane, 3-mercaptopropyltrimethoxysilane, mercaptomethylmethyldiethoxysilane, and 2-mercaptoethyltriethoxysilane, preferably one or two of 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane.

[0013] As a further technical solution, the granular filler includes a first modified granular filler and a second modified granular filler in a mass ratio of 1:9 to 9:1.

[0014] The present invention limits the mass ratio of the first modified granular filler to the second modified granular filler of 1:9 to 9:1 as the granular filler, which further improves the high temperature stability and low temperature crack resistance of the asphalt mixture.

[0015] As a further technical solution, the granular filler includes a first modified granular filler and a second modified granular filler in a mass ratio of 1:4 to 4:1.

[0016] The present invention limits the mass ratio of the first modified granular filler to the second modified granular filler of 1:4 to 4:1 as the granular filler, which further improves the high temperature stability and low temperature crack resistance of the asphalt mixture.

[0017] As a further technical solution, the raw materials of the first modified granular filler include siloxane and granular filler in a mass ratio of 0.5 to 1.5:10.

[0018] As a further technical solution, the raw materials of the second modified granular filler include a diol compound and a granular filler in a mass ratio of 1 to 3:10.

[0019] As a further technical solution, the diol compound includes one or more of p-hydroxyphenylethanol, 2-hydroxybenzyl alcohol, and m-phenylenediol.

[0020] As a further technical solution, the diol compound is p-hydroxyphenylethanol.

[0021] The present invention uses p-hydroxyphenylethanol modified granular filler as the second modified granular filler, which can further improve the high temperature stability and low temperature crack resistance of asphalt mixture compared with 2-hydroxybenzyl alcohol and isophthalic acid alcohol, because when the hydroxyl group is located at the ortho position and meta position of the benzene ring, hydrogen bonds are easily formed between molecules, and the hydrogen bonds are saturated, so the interaction between the granular filler and the asphalt is affected to a certain extent, resulting in a decrease in the high temperature stability and low temperature crack resistance of the asphalt mixture. Therefore, p-hydroxyphenylethanol is used as the second modifier. Since the hydroxyl group is located at the para position of the benzene ring, the interaction between the granular filler and the asphalt can be made stronger, thereby further improving the high temperature stability and low temperature crack resistance of the asphalt mixture.

[0022] As a further technical solution, the preparation method of the first modified granular filler comprises the following steps: dispersing the granular filler evenly in water, adding siloxane to continue dispersing, filtering, and drying to obtain the first modified granular filler; The preparation method of the second modified granular filler comprises the following steps: dissolving the diol compound in a solvent, adding the granular filler and mixing evenly, and drying to obtain the second modified granular filler.

[0023] The solvent in the present invention may be any substance that can dissolve the diol compound, preferably water.

[0024] The present invention also proposes a method for preparing an asphalt mixture, comprising the following steps: S1. After heating the asphalt to 170-180°C, an asphalt material is obtained; S2. After uniformly mixing the coarse aggregate, fine aggregate, fiber filler and granular filler, the mixture is mixed with the asphalt material to obtain an asphalt mixture.

[0025] The working principle and beneficial effects of the present invention are: The present invention uses asphalt, coarse aggregate, fine aggregate, fiber filler and granular filler, wherein the granular filler is fly ash coated mineral powder as raw materials, to provide an asphalt mixture. The fly ash coated mineral powder is used as the granular filler, and the mineral powder is coated with fly ash that has good adhesion to asphalt, thereby improving the adhesion between the asphalt and the granular filler, improving the interaction between the asphalt and the filler, and thus improving the high temperature stability and low temperature crack resistance of the asphalt mixture. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The parameters of the raw materials in the following examples and comparative examples are as follows: Asphalt is 70# asphalt; The fiber filler is basalt fiber with a length of 6 mm and an average diameter of 13 μm; The coarse aggregate is basalt crushed stone, which is composed of 11mm≤particle size<16mm and 5mm≤particle size<11mm in a mass ratio of 1:1; The fine aggregate is basalt crushed stone, which is composed of 3mm≤particle size<5mm and 0.1mm≤particle size<3mm in a mass ratio of 1:3; The fly ash is nano-grade primary fly ash; The mineral powder is S95 mineral powder and the particle size is 1200 mesh.

[0028] Example 1 S1. Mix 40 parts of mineral powder and 4 parts of fly ash, and grind them to obtain a granular filler; S2, heating 10 parts of asphalt to 170°C to obtain asphalt material; S3. After uniformly mixing 70 parts of coarse aggregate, 25 parts of fine aggregate, 0.5 parts of fiber filler and 12 parts of granular filler, continue mixing with the above-mentioned asphalt material until uniform, to obtain an asphalt mixture.

[0029] Example 2 S1. Mix 40 parts of mineral powder and 4 parts of fly ash, and grind them to obtain a granular filler; S2, heating 5 parts of asphalt to 180°C to obtain asphalt material; S3. After uniformly mixing 60 parts of coarse aggregate, 15 parts of fine aggregate, 0.2 parts of fiber filler and 8 parts of granular filler, continue mixing with the above-mentioned asphalt material until uniform, to obtain an asphalt mixture.

[0030] Example 3 S1. Mix 40 parts of mineral powder and 4 parts of fly ash, and grind them to obtain a granular filler; S2, after 20 parts of the granular filler are uniformly stirred in 200 parts of water, 2 parts of 3-mercaptopropyltrimethoxysilane are added, and the mixture is continuously stirred, filtered, and dried to obtain a first modified granular filler; S3, heating 10 parts of asphalt to 170° C. to obtain asphalt material; S4. After uniformly mixing 70 parts of coarse aggregate, 25 parts of fine aggregate, 0.5 parts of fiber filler and 12 parts of first modified granular filler, continue mixing with the above-mentioned asphalt material until uniform, to obtain an asphalt mixture.

[0031] Example 4 S1. Mix 40 parts of mineral powder and 4 parts of fly ash, and grind them to obtain a granular filler; S2, after 20 parts of the granular filler are uniformly stirred in 200 parts of water, 2 parts of 3-mercaptopropyltrimethoxysilane are added, and the mixture is continuously stirred, filtered, and dried to obtain a first modified granular filler; S3, dissolving 5 parts of p-hydroxyphenylethanol in 50 parts of water, adding 20 parts of granular filler, mixing evenly, and drying to obtain a second modified granular filler; S4, heating 10 parts of asphalt to 170° C. to obtain asphalt material; S5. Evenly mix 70 parts of coarse aggregate, 25 parts of fine aggregate, 0.5 parts of fiber filler, 10 parts of first modified granular filler and 2 parts of second modified granular filler, and continue mixing with the above-mentioned asphalt material until uniform to obtain an asphalt mixture.

[0032] Example 5 The only difference from Example 4 is that 3-mercaptopropyltrimethoxysilane is replaced by an equal amount of vinyltri(β-methoxyethoxy)silane.

[0033] Example 6 The only difference from Example 4 is that 3-mercaptopropyltrimethoxysilane is replaced by an equal amount of γ-glycidyloxypropyltrimethoxysilane.

[0034] Example 7 The only difference from Example 4 is that 3-mercaptopropyltrimethoxysilane is replaced by an equal amount of 3-aminopropyltriethoxysilane.

[0035] Example 8 The only difference from Example 4 is that the first modified granular filler is 7 parts and the second modified granular filler is 5 parts.

[0036] Example 9 The only difference from Example 4 is that there are 4 parts of the first modified granular filler and 8 parts of the second modified granular filler.

[0037] Example 10 The only difference from Example 4 is that the first modified granular filler is 2 parts and the second modified granular filler is 10 parts.

[0038] Embodiment 11 The only difference from Example 9 is that p-hydroxyphenylethanol is replaced by an equal amount of 2-hydroxybenzyl alcohol.

[0039] Example 12 The only difference from Example 9 is that p-hydroxyphenylethanol is replaced by an equal amount of isophthalic acid methanol.

[0040] Embodiment 13 S1, mixing 20 parts of mineral powder and 2 parts of fly ash, and grinding them to obtain a granular filler; S2, dissolving 5 parts of p-hydroxyphenylethanol in 50 parts of water, adding 20 parts of granular filler, mixing evenly, and drying to obtain a second modified granular filler; S4, heating 10 parts of asphalt to 170° C. to obtain asphalt material; S5. After uniformly mixing 70 parts of coarse aggregate, 25 parts of fine aggregate, 0.5 parts of fiber filler and 12 parts of second modified granular filler, continue mixing with the above-mentioned asphalt material until uniform, to obtain an asphalt mixture.

[0041] Comparative Example 1 S1. After heating 10 parts of asphalt to 170°C, an asphalt material is obtained; S2. Evenly mix 70 parts of coarse aggregate, 25 parts of fine aggregate, 0.5 parts of fiber filler, 10.8 parts of mineral powder and 1.2 parts of fly ash, and continue to mix with the above-mentioned asphalt material until uniform to obtain an asphalt mixture.

[0042] Performance Test: (1) A 250 mm × 30 mm × 35 mm rectangular test specimen was prepared and tested for -10 °C low-temperature bending failure strain using a press with a loading rate of 50 mm / min. (2) Prepare a test specimen with a diameter of 10 mm and a thickness of 2 mm, and use a wheel ground pressure of 0.7 MPa to test the dynamic stability at 60°C; The test results are recorded in Table 1.

[0043] Table 1 High temperature stability and low temperature crack resistance of asphalt mixture

[0044] It can be seen from Table 1 that the asphalt mixture provided by the present invention has a dynamic stability of more than 8261 times / mm at 60°C and a low-temperature bending failure strain of more than 4202με at -10°C, and has good high-temperature stability and low-temperature crack resistance.

[0045] Compared with Comparative Example 1, fly ash-coated mineral powder is added as granular filler in Example 1, and the 60°C dynamic stability and -10°C low-temperature bending failure strain of the obtained asphalt mixture are higher than those of Comparative Example 1, indicating that fly ash-coated mineral powder as granular filler can improve the high-temperature stability and low-temperature crack resistance of asphalt mixture.

[0046] The 60°C dynamic stability and -10°C low-temperature bending failure strain of the asphalt mixtures obtained in Examples 3 to 13 are higher than those in Example 1, indicating that the use of siloxane-modified granular fillers and / or diol compound-modified granular fillers can further improve the high-temperature stability and low-temperature crack resistance of the asphalt mixture.

[0047] The 60°C dynamic stability and -10°C low-temperature bending failure strain of the asphalt mixture obtained in Example 4 are higher than those in Examples 5 to 7, indicating that the high-temperature stability and low-temperature crack resistance of the asphalt mixture can be further improved when the mercaptosiloxane-modified granular filler is used as the first modified granular filler.

[0048] The 60°C dynamic stability and -10°C low-temperature bending failure strain of the asphalt mixtures obtained in Example 4 and Examples 8-10 are higher than those in Example 3 and Example 13, indicating that the first modified granular filler and the second modified granular filler used in combination as granular fillers can further improve the high-temperature stability and low-temperature crack resistance of the asphalt mixture.

[0049] The 60°C dynamic stability and -10°C low-temperature bending failure strain of the asphalt mixtures obtained in Examples 8-9 are higher than those in Example 4 and Example 10, indicating that the mass ratio of the first modified granular filler to the second modified granular filler is 1:4-4:1, which can further improve the high temperature stability and low temperature crack resistance of the asphalt mixture.

[0050] The 60°C dynamic stability and -10°C low-temperature bending failure strain of the asphalt mixture obtained in Examples 8-9 are higher than those in Examples 11-12, indicating that the use of p-hydroxyphenylethanol-modified granular filler as the second modified granular filler can further improve the high-temperature stability and low-temperature crack resistance of the asphalt mixture.

[0051] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An asphalt mixture, characterized in that: The invention comprises the following components in parts by weight: 5-10 parts of asphalt, 60-70 parts of coarse aggregate, 15-25 parts of fine aggregate, 0.2-0.5 parts of fiber filler and 8-12 parts of granular filler, wherein the granular filler is fly ash coated mineral powder.

2. An asphalt mixture according to claim 1, characterized in that: The preparation method of the granular filler comprises the following steps: mixing mineral powder and fly ash, and grinding them to obtain the granular filler.

3. An asphalt mixture according to claim 1, characterized in that: The raw materials of the granular filler include fly ash and mineral powder in a mass ratio of 1 to 3:

20.

4. An asphalt mixture according to any one of claims 1 to 3, characterized in that: The granular filler includes a first modified granular filler and / or a second modified granular filler, the modifier of the first modified granular filler is siloxane, and the modifier of the second modified granular filler is a diol compound.

5. An asphalt mixture according to claim 4, characterized in that: The siloxane is mercaptosiloxane.

6. An asphalt mixture according to claim 5, characterized in that: The granular filler includes a first modified granular filler and a second modified granular filler in a mass ratio of 1:9 to 9:

1.

7. An asphalt mixture according to claim 6, characterized in that: The granular filler includes a first modified granular filler and a second modified granular filler in a mass ratio of 1:4 to 4:

1.

8. An asphalt mixture according to claim 4, characterized in that: The diol compound includes one or more of p-hydroxyphenylethanol, 2-hydroxybenzyl alcohol, and m-phenylenediol.

9. An asphalt mixture according to claim 6 or 7, characterized in that: The preparation method of the first modified granular filler comprises the following steps: dispersing the granular filler uniformly in water, adding siloxane to continue dispersing, filtering, and drying to obtain the first modified granular filler; The preparation method of the second modified granular filler comprises the following steps: dissolving the diol compound in a solvent, adding the granular filler and mixing evenly, and drying to obtain the second modified granular filler.

10. The method for preparing an asphalt mixture according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. After heating the asphalt to 170-180°C, an asphalt material is obtained; S2. After uniformly mixing the coarse aggregate, fine aggregate, fiber filler and granular filler, the mixture is mixed with the asphalt material to obtain an asphalt mixture.

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