High-color-stable anti-flying-sand gravel type open-graded colored asphalt wearing layer and preparation method thereof

Abstract

The application provides a high-color-stability anti-spalling gravel type open-graded color asphalt wearing layer and a preparation method thereof, and relates to the technical field of asphalt. The open-graded color asphalt wearing layer raw material comprises 4.5-5.5 parts of interface strengthening decolorized asphalt, 75-83 parts of coarse aggregate, 7-11 parts of fine aggregate, 0.3-0.5 parts of filler, 3-5 parts of inorganic pigment, 0.2-0.3 parts of composite fiber, 0.04-0.08 parts of ultraviolet absorber and 0.1-0.25 parts of aggregate modifier. The application can enhance the adhesion of decolorized asphalt, inorganic pigment and composite fiber and the like components by the flexible wrapping effect of interface strengthening asphalt through suitable raw material ratio, improve color stability, avoid the brittle cracking problem of open-graded color asphalt wearing layer, improve the anti-stripping performance, and effectively solve the industry common problem that the traditional color open-graded pavement is caused by the adhesion failure and pigment deterioration, the landscape function declines fast, and the maintenance cost is high.

Description

Technical Field

[0001] This invention relates to the field of asphalt technology, and in particular to a high-color-stability, anti-scattering gravel open-graded colored asphalt wear layer and its preparation method. Background Technology

[0002] Open Graded Friction Course (OGFC) is a functional pavement structure characterized by high porosity. Its design concept is to form a skeleton by interlocking coarse aggregates and retain interconnected pores by low filling rate of fine aggregates, so as to achieve the following core functions: (1) Drainage function: It can quickly drain water from the road surface, reduce water mist and glare on rainy days, and improve driving safety. (2) Noise reduction function: High porosity can absorb high-frequency noise generated by tire contact with the road surface, which is suitable for landscape roads and residential areas. (3) Anti-skid function: The macroscopic structure formed by the exposed coarse aggregates increases the friction coefficient and meets the anti-skid needs of pedestrians and non-motorized vehicles. On this basis, colored pigments are added and the mix ratio is adjusted so that the maximum nominal particle size is 4.75mm, so that the colored pavement structure can be coordinated with the surrounding buildings and landscapes; in addition, the finer particle gradation is intersected with other gradations, and the visual perception is more delicate, creating a comfortable and beautiful visual effect. Its typical application scenarios are: light-load traffic spaces (including sidewalks, pedestrian streets, bicycle lanes, etc.), with a design load of ≤50kN; high-precipitation areas: reducing the risk of water damage through structural drainage, such as landscape bridges and waterfront walkways in rainy areas of the south.

[0003] However, open-graded asphalt wearing course materials still have the following problems during use:

[0004] (1) Interface bonding failure and insufficient toughness of the mixture: The aggregate has a small particle size and a large specific surface area. The bonding force of the traditional asphalt film is insufficient to resist the vibration of pedestrian loads or temperature deformation, resulting in aggregate detachment. The high porosity leads to a relatively low asphalt content, and the toughness of conventional asphalt raw materials is insufficient, making it easy to scatter. Conventional solutions: Use high viscosity modified asphalt (such as SBS modified asphalt) to improve the bonding force, but the single modification has a limited reinforcing effect on small-particle-size aggregates; increase the fine aggregate filling rate, but this will reduce the porosity to 15%-18%, weakening the drainage function.

[0005] (2) Weather resistance defects of colored asphalt: The pigments used in traditional colored asphalt have poor compatibility with asphalt, and are prone to pigment agglomeration and precipitation or oxidation and fading under ultraviolet radiation. In addition, inorganic pigments themselves have insufficient UV resistance. Conventional solutions: Add antioxidants or use a protective coating on the surface of the wear layer to improve durability.

[0006] (3) Environmental sensitivity of open-graded aggregates: High porosity exacerbates water and oxygen intrusion, leading to a decrease in the adhesion grade of the asphalt-aggregate interface. Conventional solutions: Use anti-stripping agents to improve interfacial adhesion; reduce construction temperature (such as warm mix technology) to reduce asphalt aging, but this will affect compaction and pore connectivity. Summary of the Invention

[0007] This invention addresses the problems of excessive color difference and aggregate interface adhesion failure caused by small particle size and high porosity in existing gravel-type open-graded colored asphalt wearing layers in light-load landscape traffic spaces. It provides a gravel-type open-graded colored asphalt wearing layer with high color stability and anti-scattering performance, suitable for pedestrian main road scenarios such as sidewalks, pedestrian streets, and landscape bridges.

[0008] The open-graded colored asphalt wearing course of the present invention, while meeting the requirements of open-graded drainage function and low noise performance, achieves improved color retention, improved anti-scattering performance and improved water damage performance during the service life, solving the common industry problem of rapid landscape function degradation and high maintenance cost caused by bonding failure and pigment deterioration of traditional colored open-graded pavement.

[0009] The technical solution of this invention is implemented as follows:

[0010] A high-color-stability, anti-scattering gravel open-graded colored asphalt wear-resistant layer comprises the following raw materials in parts by weight: 4.5-5.5 parts of interface-reinforced decolorized asphalt, 75-83 parts of coarse aggregate, 7-11 parts of fine aggregate, 0.3-0.5 parts of filler, 3-5 parts of inorganic pigment, 0.2-0.3 parts of composite fiber, 0.04-0.08 parts of ultraviolet absorber, and 0.1-0.25 parts of aggregate modifier;

[0011] The preparation method of the interface-reinforced decolorized asphalt is as follows: KH550 coupling agent and dodecylamine are added to ethanol to obtain a premix, and then acetic acid is added and stirred once to obtain an interface-reinforced premix. After heating the decolorized asphalt, the interface-reinforced premix is ​​added dropwise and stirred twice to obtain the interface-reinforced decolorized asphalt.

[0012] Furthermore, the mass ratio of KH550 coupling agent, dodecylamine, and ethanol is 1-2:1-2:3-6; the amount of acetic acid added is 0.5%-1.0% of the mass of the premix; the amount of interface-reinforced premix added is 2.5%-3.0% of the mass of the decolorized asphalt; and the decolorized asphalt is No. 70 matrix decolorized asphalt.

[0013] Furthermore, the first stirring is carried out at 25-35℃ and 400-500r / min for 15-20min; the asphalt is heated to 120-130℃; the second stirring is carried out at 4000-5000r / min for 25-30min.

[0014] Furthermore, the coarse aggregate is one or more of basalt and diabase; the fine aggregate is sand and gravel with a particle size of less than 2.36 mm; more than 80% of the fine aggregate particles have more than three crushing surfaces and a specific surface area ≥ 600 cm². 2 / g; the filler is limestone ore powder.

[0015] Furthermore, the inorganic pigment is one or more of the following: iron oxide red, iron oxide yellow, iron oxide black, ultramarine blue, chromium oxide green, cadmium yellow, cobalt blue, molybdenum chromium red, iron blue, zinc yellow, and cadmium sulfide.

[0016] Furthermore, the composite fiber comprises pretreated polypropylene fiber and pretreated lignin fiber in a mass ratio of 1-2:2-3.

[0017] Furthermore, the method for preparing the pretreated lignin fiber is as follows: lignin fiber is placed in a sodium hydroxide solution with a mass concentration of 4%-6% and treated at 50-60℃ and a stirring speed of 80-100 r / min for 10-15 min, then rinsed with water and dried to obtain pretreated lignin fiber; the polypropylene fiber is a short fiber with a length of 6-8 mm; the pretreated polypropylene fiber is obtained by ultrasonic treatment of polypropylene fiber with polyetheramine; the mass ratio of polypropylene fiber to polyetheramine is 8-10:1-1.6.

[0018] Furthermore, the pretreatment method for polypropylene fibers is as follows: after mixing polypropylene fibers with polyetheramine, ultrasonic treatment is carried out for 20-30 minutes at a temperature of 60-80℃ and a power of 180-240W, and then dried to obtain pretreated polypropylene fibers.

[0019] Furthermore, the ultraviolet absorber is one or more of ultraviolet absorbers UV-531, UV-329, UV-234, and UV-326; the aggregate modifier includes sodium didodecyl phosphate, KH560 silane coupling agent, and TTS titanate coupling agent in a mass ratio of 1-1.6:3-4:3-4.

[0020] A method for preparing a high-color-stability, anti-scattering gravel open-graded colored asphalt wear-resistant layer includes the following steps:

[0021] S1. Add the powdered ultraviolet absorber to naphthenic oil and mix to form a slurry; add sodium didodecyl phosphate from the aggregate modifier to dimethylformamide and stir to obtain a mixture;

[0022] S2. Heat the coarse aggregate and fine aggregate to 160-170℃ respectively and put them into the mixing tank. Spray the mixture and dry mix. Then spray the KH560 silane coupling agent and TTS titanate coupling agent in the aggregate modifier and dry mix. Then add the inorganic pigment and dry mix again to obtain the premix.

[0023] S3. Add composite fiber to the premix and dry mix. Heat the interface-reinforced decolorized asphalt to 160-170℃ and spray it into the mixing tank. Simultaneously spray the slurry obtained in step S1. Complete the addition of filler within 5 seconds after the interface-reinforced decolorized asphalt is sprayed. Complete the production after wet mixing.

[0024] Furthermore, the mass ratio of the ultraviolet absorber to the naphthenic oil is 1-2:2-4; the mass ratio of sodium didodecyl phosphate to dimethylformamide is 1-2:5-7; the dry mixing time is 10-20s and the rotation speed is 120-150r / min; the wet mixing time is 40-50s and the rotation speed is 300-400r / min.

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

[0026] This invention uses interface-reinforced asphalt, aggregates, composite fibers, and aggregate modifiers as raw materials. Through appropriate raw material ratios, it can enhance the adhesion between the decolorized asphalt and aggregates, inorganic pigments, composite fibers, and other components by utilizing the flexible encapsulation effect of interface-reinforced asphalt. This avoids the brittle cracking problem of open-graded colored asphalt wearing layers and improves its anti-stripping performance. At the same time, by using appropriately graded aggregates and fillers and treating them with suitable modifiers, it can effectively improve the self-cleaning ability of pores, reduce the risk of dust retention and blockage, and achieve a balance between long-term permeability and structural stability. In addition, it can also enable inorganic pigments to uniformly and stably encapsulate and adhere to asphalt and aggregates, thereby improving the color stability of open-graded colored asphalt wearing layers and extending their service life. This effectively solves the common industry problem of rapid landscape function degradation and high maintenance costs caused by adhesion failure and pigment deterioration in traditional colored open-graded pavements.

[0027] In the preparation process, KH550 coupling agent, dodecylamine, and ethanol are used as interface strengthening liquids to treat the decolorized asphalt. The long carbon chain of dodecylamine is embedded in the decolorized asphalt, which can effectively enhance the cohesion between the decolorized asphalt and raw materials such as aggregates. At the same time, the synergistic effect of hydrolyzed KH550, which provides rigid chemical bonds, can also reduce the erosion of the interface by water. This effectively enhances the adhesion between the decolorized asphalt and raw materials such as aggregates, inorganic pigments, and composite fibers, and avoids the risk of cracking and peeling caused by water erosion. It also avoids decolorization and improves its service life.

[0028] The composite fiber of this invention is composed of pretreated polypropylene fiber and pretreated lignin fiber in a specific ratio. The lignin fiber, after being treated with sodium hydroxide, can improve its adsorption of decolorized asphalt mortar, stabilize the asphalt-aggregate ratio, compensate for insufficient aggregate bonding strength, and effectively reduce precipitation and scattering. The polypropylene fiber, using short fibers of 6-8 mm in length, and treated with polyetheramine, can improve its mechanical interlocking with asphalt and other raw materials, absorb load stress, provide high-strength skeletal support, and improve the rutting resistance and crack resistance of the open-graded colored asphalt wear layer, thus compensating for the insufficient rigidity of the lignin fiber. The combination of the two fibers synergistically improves adhesion and structure.

[0029] During the preparation process, the combined action of sodium dodecyl phosphate, KH560 silane coupling agent, and TTS titanate coupling agent not only anchors and enhances the adhesion between aggregates and asphalt, but also pre-coats inorganic pigments, enhancing the uniform dispersion and adhesion stability of inorganic pigments. This effectively solves the problems of pigment dispersion and fading, while also avoiding the brittle cracking problem of open-graded colored asphalt wear layers. Detailed Implementation

[0030] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0031] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0032] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0033] The relevant technical indicators of the raw materials that need to be controlled in the coarse aggregate, fine aggregate, filler, inorganic pigment, etc. of this invention are as follows:

[0034] 1. Coarse aggregate

[0035] The coarse aggregate of this invention uses neutral stone: basalt or diabase.

[0036] Neutral aggregates (basalt, diabase) offer high strength and abrasion resistance: basalt has a crushing value ≤16%, making it suitable for scenarios with occasional light vehicle traffic (such as fire lanes), and its wear life is 2-3 years longer than limestone; it also has great potential for surface roughening: through crushing processes (such as impact crushing), it can form multi-faceted particles, increasing the specific surface area by 20%, thus compensating for the insufficient bonding strength of neutral aggregates. Relevant technical specifications are shown in the table below.

[0037] Table 1 Technical Specifications of Coarse Aggregates

[0038]

[0039] 2. Fine aggregate

[0040] Fine aggregates refer to sand and gravel with a particle size of less than 2.36 mm. To enhance the mechanical interlocking strength of aggregates in asphalt mixtures, manufactured sand with better angularity is used in production, ensuring that more than 80% of the particles have more than three crushing surfaces and a specific surface area ≥ 600 cm². 2 / g. The relevant technical specifications are shown in the table below.

[0041] Table 2 Technical Specifications of Fine Aggregates

[0042]

[0043] 3. Packing material

[0044] Limestone ore powder is used. The relevant technical specifications are shown in the table below.

[0045] Table 3 Technical Specifications of Packing Material

[0046]

[0047] 4. Inorganic pigments

[0048] Inorganic pigments (colorants) require the use of inorganic materials (metal oxide colorants, metal salt colorants). They must not easily fade or decompose under long-term sunlight exposure, be insoluble in water, and easily disperse and blend during mixing. Furthermore, they must not react at the application temperature. Suitable pigments include iron oxide red (Fe2O3), iron oxide yellow (FeO(OH)), iron oxide black (Fe3O4), and ultramarine blue (Na8-10Al6Si6O). 24 The following pigments are listed: S2-4, chromium oxide green (Cr2O3), cadmium yellow (CdS), cobalt blue (CoAl2O4), molybdenum chromium red (PbCrMoO4), iron blue (Fe4[Fe(CN)6]3), zinc yellow (ZnCrO4), and cadmium sulfide (CdS・ZnS). The relevant technical specifications are shown in the table below.

[0049] Table 4 Technical Specifications of Inorganic Pigments

[0050]

[0051] Example 1

[0052] The high color stability and anti-scattering gravel open-graded colored asphalt wear layer of this embodiment includes the following raw materials in parts by weight: 4.8 parts of interface-reinforced decolorized asphalt, 82 parts of coarse aggregate, 11 parts of fine aggregate, 0.5 parts of filler, 4 parts of inorganic pigment, 0.25 parts of composite fiber, 0.04 parts of ultraviolet absorber, and 0.25 parts of aggregate modifier.

[0053] The coarse aggregate consists of basalt and diabase in a 1:1 mass ratio; the fine aggregate consists of particles smaller than 2.36 mm, with more than 80% of the particles having three or more fracture surfaces and a specific surface area ≥ 600 cm². 2 / g of sand and gravel; the filler is limestone powder; the inorganic pigment is iron oxide yellow and chromium oxide green in a mass ratio of 1:3; the composite fiber includes pretreated polypropylene fiber and pretreated lignin fiber in a mass ratio of 2:3; the ultraviolet absorber is ultraviolet absorber UV-531; the aggregate modifier includes sodium didodecyl phosphate, KH560 silane coupling agent, and TTS titanate coupling agent in a mass ratio of 1.6:3:3.

[0054] The preparation method of interface-reinforced decolorized asphalt is as follows: KH550 coupling agent, dodecylamine, and ethanol are added to ethanol in a mass ratio of 2:2:5 to obtain a premix. Then, acetic acid is added and stirred once for 15 minutes at 30℃ and 500r / min to obtain an interface-reinforced premix. The amount of acetic acid added is 0.8% of the mass of the premix. The No. 70 matrix decolorized asphalt is heated to 120℃, and then the interface-reinforced premix is ​​slowly added dropwise and stirred twice for 25 minutes at 4000r / min. The amount of interface-reinforced premix added is 3.0% of the mass of the decolorized asphalt to obtain interface-reinforced decolorized asphalt.

[0055] The pretreatment method for polypropylene fibers is as follows: Polypropylene fibers and polyetheramine are mixed in a mass ratio of 9:1.5. The 6mm long polypropylene fibers are then ultrasonically treated at 80℃ and 240W for 26 minutes, and then dried to obtain pretreated polypropylene fibers.

[0056] The method for preparing pretreated lignin fibers is as follows: lignin fibers are placed in a 5% sodium hydroxide solution and treated at 60°C and a stirring speed of 100 r / min for 15 min. After rinsing with water and drying, pretreated lignin fibers are obtained.

[0057] The method for preparing the open-graded colored asphalt wearing course includes the following steps:

[0058] S1. According to the mass ratio of ultraviolet absorber to naphthenic oil of 1:2, the powdered ultraviolet absorber is added to naphthenic oil and mixed at 80°C to form a slurry; according to the mass ratio of sodium dodecyl phosphate to dimethylformamide of 2:7, the sodium dodecyl phosphate in the aggregate modifier is added to dimethylformamide and stirred to obtain a mixture.

[0059] S2. After heating the coarse aggregate and fine aggregate to 170℃, put them into the mixing tank, spray the mixture and dry mix for 12s at a speed of 150r / min. Then spray the KH560 silane coupling agent and TTS titanate coupling agent in the aggregate modifier and dry mix for 15s. Then add the inorganic pigment and dry mix for 15s to obtain the premix.

[0060] S3. Add composite fiber to the premix and dry mix for 10 seconds. Heat the interface-reinforced decolorized asphalt to 170°C and spray it into the mixing tank. Simultaneously spray the slurry obtained in step S1. Complete the addition of filler within 5 seconds after the interface-reinforced decolorized asphalt is sprayed. Wet mix for 50 seconds at a speed of 400 r / min to complete the production.

[0061] Example 2

[0062] The high color stability and anti-scattering gravel open-graded colored asphalt wear layer of this embodiment includes the following raw materials in parts by weight: 4.5 parts of interface-reinforced decolorized asphalt, 75 parts of coarse aggregate, 9 parts of fine aggregate, 0.4 parts of filler, 3 parts of inorganic pigment, 0.2 parts of composite fiber, 0.08 parts of ultraviolet absorber, and 0.2 parts of aggregate modifier.

[0063] The coarse aggregate is diabase; the fine aggregate consists of particles smaller than 2.36 mm, with more than 80% of the particles having three or more fracture surfaces and a specific surface area ≥ 600 cm². 2 / g of sand and gravel; the filler is limestone powder; the inorganic pigment is iron oxide red; the composite fiber includes pretreated polypropylene fiber and pretreated lignin fiber in a mass ratio of 1:2; the ultraviolet absorber is ultraviolet absorber UV-329; the aggregate modifier includes sodium dodecyl phosphate, KH560 silane coupling agent, and TTS titanate coupling agent in a mass ratio of 1:4:3.

[0064] The preparation method of interface-reinforced decolorized asphalt is as follows: KH550 coupling agent, dodecylamine, and ethanol are added to ethanol in a mass ratio of 1:2:3 to obtain a premix. Then, acetic acid is added and stirred once for 20 minutes at 25℃ and 400r / min to obtain an interface-reinforced premix. The amount of acetic acid added is 0.5% of the mass of the premix. The No. 70 matrix decolorized asphalt is heated to 130℃, and then the interface-reinforced premix is ​​slowly added dropwise and stirred twice for 30 minutes at 4500r / min. The amount of interface-reinforced premix added is 2.5% of the mass of the decolorized asphalt to obtain interface-reinforced decolorized asphalt.

[0065] The pretreatment method for polypropylene fibers is as follows: the polypropylene fibers and polyetheramine are mixed at a mass ratio of 10:1, and then ultrasonically treated at a temperature of 70℃ and a power of 180W for 20 minutes, and then dried to obtain the pretreated polypropylene fibers.

[0066] The method for preparing pretreated lignin fibers is as follows: lignin fibers are placed in a 4% sodium hydroxide solution and treated at 50°C and a stirring speed of 80 r / min for 12 min. After rinsing with water and drying, pretreated lignin fibers are obtained.

[0067] The method for preparing the open-graded colored asphalt wearing course includes the following steps:

[0068] S1. According to the mass ratio of ultraviolet absorber to naphthenic oil of 1:4, the powdered ultraviolet absorber is added to naphthenic oil and mixed at 70°C to form a slurry; according to the mass ratio of sodium dodecyl phosphate to dimethylformamide of 1:6, the sodium dodecyl phosphate in the aggregate modifier is added to dimethylformamide and stirred to obtain a mixture.

[0069] S2. After heating the coarse aggregate and fine aggregate to 160℃, put them into the mixing tank, spray the mixture and dry mix for 10s at a speed of 120r / min. Then spray the KH560 silane coupling agent and TTS titanate coupling agent in the aggregate modifier and dry mix for 20s. Then add the inorganic pigment and dry mix for 12s to obtain the premix.

[0070] S3. Add composite fiber to the premix and dry mix for 15 seconds. Heat the interface-reinforced decolorized asphalt to 160°C and spray it into the mixing tank. Simultaneously spray the slurry obtained in step S1. Complete the addition of filler within 5 seconds after the interface-reinforced decolorized asphalt is sprayed. Complete the production by wet mixing for 40 seconds at a speed of 300 r / min.

[0071] Example 3

[0072] The high color stability and anti-scattering gravel open-graded colored asphalt wear layer of this embodiment includes the following raw materials in parts by weight: 5.5 parts of interface-reinforced decolorized asphalt, 79 parts of coarse aggregate, 6 parts of fine aggregate, 0.3 parts of filler, 5 parts of inorganic pigment, 0.3 parts of composite fiber, 0.06 parts of ultraviolet absorber, and 0.1 parts of aggregate modifier.

[0073] The coarse aggregate is basalt; the fine aggregate consists of particles smaller than 2.36 mm, with more than 80% of the particles having three or more crushing surfaces and a specific surface area ≥ 600 cm². 2 / g of sand and gravel; the filler is limestone powder; the inorganic pigment is composed of iron blue, cobalt blue and ultramarine blue in a 5:1:1 ratio; the composite fiber includes pretreated polypropylene fiber and pretreated lignin fiber in a mass ratio of 1:3; the ultraviolet absorber is composed of ultraviolet absorber UV-234 and ultraviolet absorber UV-326 in a mass ratio of 1:1; the aggregate modifier includes sodium didodecyl phosphate, KH560 silane coupling agent and TTS titanate coupling agent in a mass ratio of 1.2:3:4.

[0074] The preparation method of interface-reinforced decolorized asphalt is as follows: KH550 coupling agent, dodecylamine, and ethanol are added to ethanol in a mass ratio of 2:1:6 to obtain a premix. Then, acetic acid is added and stirred once at 35℃ and 450r / min for 20min to obtain an interface-reinforced premix. The amount of acetic acid added is 1.0% of the mass of the premix. The No. 70 matrix decolorized asphalt is heated to 120℃, and then the interface-reinforced premix is ​​slowly added dropwise and stirred twice at 5000r / min for 30min. The amount of interface-reinforced premix added is 2.6% of the mass of the decolorized asphalt to obtain interface-reinforced decolorized asphalt.

[0075] The pretreatment method for polypropylene fibers is as follows: Polypropylene fibers and polyetheramine are mixed in a mass ratio of 8:1.6. The mixture is then ultrasonically treated at 60°C and 200W for 30 minutes, and then dried to obtain pretreated polypropylene fibers.

[0076] The method for preparing pretreated lignin fibers is as follows: lignin fibers are placed in a 6% sodium hydroxide solution and treated at 55°C and a stirring speed of 90 r / min for 10 min. After rinsing with water and drying, pretreated lignin fibers are obtained.

[0077] The method for preparing the open-graded colored asphalt wearing course includes the following steps:

[0078] S1. According to the mass ratio of ultraviolet absorber to naphthenic oil of 2:3, the powdered ultraviolet absorber is added to naphthenic oil and mixed at 60°C to form a slurry; according to the mass ratio of sodium dodecyl phosphate to dimethylformamide of 1:5, the sodium dodecyl phosphate in the aggregate modifier is added to dimethylformamide and stirred to obtain a mixture.

[0079] S2. After heating the coarse aggregate and fine aggregate to 170℃, put them into the mixing tank, spray the mixture and dry mix for 15s at a speed of 140r / min. Then spray the KH560 silane coupling agent and TTS titanate coupling agent in the aggregate modifier and dry mix for 10s. Then add the inorganic pigment and dry mix again for 180s to obtain the premix.

[0080] S3. Add composite fiber to the premix and dry mix for 120 seconds. Heat the interface-reinforced decolorized asphalt to 170°C and spray it into the mixing tank. Simultaneously spray the slurry obtained in step S1. Complete the addition of filler within 5 seconds after the interface-reinforced decolorized asphalt is sprayed. Complete the production by wet mixing for 50 seconds at a speed of 400 r / min.

[0081] Comparative Example 1

[0082] The difference between this comparative example and Example 1 is that the interface-reinforced decolorizing bitumen is replaced with simple No. 70 matrix decolorizing bitumen, while the rest remains the same as in Example 1.

[0083] This comparative example of a high-color-stability, anti-scattering gravel open-graded colored asphalt wear course includes the following raw materials in parts by weight: 4.8 parts of No. 70 base decolorized asphalt, 82 parts of coarse aggregate, 11 parts of fine aggregate, 0.5 parts of filler, 4 parts of inorganic pigment, 0.25 parts of composite fiber, 0.04 parts of ultraviolet absorber, and 0.25 parts of aggregate modifier.

[0084] Comparative Example 2

[0085] The difference between this comparative example and Example 1 is that only KH550 coupling agent was added during the preparation of interface-reinforced decolorized asphalt, while the rest remained the same as in Example 1.

[0086] The preparation method of interface-reinforced decolorized asphalt is as follows: KH550 coupling agent and ethanol are added to ethanol at a mass ratio of 4:5 to obtain a premix. Then, acetic acid is added and stirred once at 30℃ and 500r / min for 15min to obtain an interface-reinforced premix. The amount of acetic acid added is 0.8% of the mass of the premix. The No. 70 matrix decolorized asphalt is heated to 120℃, and then the interface-reinforced premix is ​​slowly added dropwise and stirred twice at 4000r / min for 25min. The amount of interface-reinforced premix added is 3.0% of the mass of the decolorized asphalt to obtain interface-reinforced decolorized asphalt.

[0087] Comparative Example 3

[0088] The difference between this comparative example and Example 1 is that only dodecylamine was added during the preparation of interface-strengthened decolorized asphalt, while the rest remained the same as in Example 1.

[0089] The preparation method of interface-reinforced decolorized asphalt is as follows: Dodecylamine is added to ethanol at a mass ratio of 4:5 to obtain a premix, and then acetic acid is added and stirred once at 30℃ and 500r / min for 15min to obtain an interface-reinforced premix. The amount of acetic acid added is 0.8% of the mass of the premix. The No. 70 matrix decolorized asphalt is heated to 120℃, and then the interface-reinforced premix is ​​slowly added dropwise and stirred twice at 4000r / min for 25min. The amount of interface-reinforced premix added is 3.0% of the mass of the decolorized asphalt to obtain interface-reinforced decolorized asphalt.

[0090] Comparative Example 4

[0091] The difference between this comparative example and Example 1 is that the mass ratio of KH550 coupling agent, dodecylamine, and ethanol in the preparation of interface-reinforced decolorized asphalt is 0.2:3:10, while the rest remains the same as in Example 1.

[0092] The preparation method of interface-reinforced decolorized asphalt is as follows: KH550 coupling agent, dodecylamine, and ethanol are added to ethanol at a mass ratio of 0.2:3:10 to obtain a premix. Then, acetic acid is added and stirred once at 30℃ and 500r / min for 15min to obtain an interface-reinforced premix. The amount of acetic acid added is 0.8% of the mass of the premix. The No. 70 matrix decolorized asphalt is heated to 120℃, and then the interface-reinforced premix is ​​slowly added dropwise and stirred twice at 4000r / min for 25min. The amount of interface-reinforced premix added is 3.0% of the mass of the decolorized asphalt to obtain interface-reinforced decolorized asphalt.

[0093] Comparative Example 5

[0094] The difference between this comparative example and Example 1 is that no composite fiber is added to the raw materials, while the rest remains the same as in Example 1.

[0095] This comparative example of a high-color-stability, anti-scattering gravel open-graded colored asphalt wear course includes the following raw materials in parts by weight: 4.8 parts of interface-reinforced decolorized asphalt, 82 parts of coarse aggregate, 11 parts of fine aggregate, 0.5 parts of filler, 4 parts of inorganic pigment, 0.04 parts of ultraviolet absorber, and 0.25 parts of aggregate modifier.

[0096] Comparative Example 6

[0097] The difference between this comparative example and Example 1 is that the polypropylene fiber was not pretreated and the length of the polypropylene fiber was changed to 30 mm, while the rest remained the same as in Example 1.

[0098] Comparative Example 7

[0099] The difference between this comparative example and Example 1 is that the composite fiber is replaced with pretreated polypropylene fiber, while the rest remains the same as in Example 1.

[0100] This comparative example of a high-color-stability, anti-scattering gravel open-graded colored asphalt wear course includes the following raw materials in parts by weight: 4.8 parts of interface-reinforced decolorized asphalt, 82 parts of coarse aggregate, 11 parts of fine aggregate, 0.5 parts of filler, 4 parts of inorganic pigment, 0.25 parts of pretreated polypropylene fiber, 0.04 parts of ultraviolet absorber, and 0.25 parts of aggregate modifier.

[0101] Comparative Example 8

[0102] The difference between this comparative example and Example 1 is that the composite fiber is replaced with pretreated lignin fiber, while the rest remains the same as in Example 1.

[0103] This comparative example of a high-color-stability, anti-scattering gravel open-graded colored asphalt wear course includes the following raw materials in parts by weight: 4.8 parts of interface-reinforced decolorized asphalt, 82 parts of coarse aggregate, 11 parts of fine aggregate, 0.5 parts of filler, 4 parts of inorganic pigment, 0.25 parts of pretreated lignin fiber, 0.04 parts of ultraviolet absorber, and 0.25 parts of aggregate modifier.

[0104] Comparative Example 9

[0105] The difference between this comparative example and Example 1 is that the raw materials do not contain aggregate modifiers, while the rest are the same as in Example 1.

[0106] This comparative example of a high-color-stability, anti-scattering gravel open-graded colored asphalt wear course includes the following raw materials in parts by weight: 4.8 parts of interface-reinforced decolorized asphalt, 82 parts of coarse aggregate, 11 parts of fine aggregate, 0.5 parts of filler, 4 parts of inorganic pigment, 0.25 parts of composite fiber, and 0.04 parts of ultraviolet absorber.

[0107] Comparative Example 10

[0108] The difference between this comparative example and Example 1 is that the aggregate modifier does not contain sodium didodecyl phosphate; otherwise, it remains the same as Example 1. The aggregate modifier includes KH560 silane coupling agent and TTS titanate coupling agent in a mass ratio of 3:3.

[0109] The method for preparing the open-graded colored asphalt wearing course includes the following steps:

[0110] S1. According to the mass ratio of ultraviolet absorber to naphthenic oil of 1:2, the powdered ultraviolet absorber is added to the naphthenic oil and mixed at 80°C to form a slurry.

[0111] S2. After heating the coarse aggregate and fine aggregate to 170℃ respectively, put them into the mixing tank. Then spray the KH560 silane coupling agent and TTS titanate coupling agent in the aggregate modifier and dry mix for 15s at a speed of 150r / min. Then add the inorganic pigment and dry mix for another 15s to obtain the premix.

[0112] S3. Add composite fiber to the premix and dry mix for 10 seconds. Heat the interface-reinforced decolorized asphalt to 170°C and spray it into the mixing tank. Simultaneously spray the slurry obtained in step S1. Complete the addition of filler within 5 seconds after the interface-reinforced decolorized asphalt is sprayed. Wet mix for 50 seconds at a speed of 400 r / min to complete the production.

[0113] Open-graded colored asphalt wear-resistant layers were prepared according to the preparation methods of Examples 1-3 and Comparative Examples 1-10 above, and relevant index tests were conducted according to the test methods in Table 5 below. The test results are shown in Table 6.

[0114] Table 5. Experimental Item Indicators

[0115]

[0116] Table 6. Experimental results of open-graded colored asphalt wearing courses in the examples and comparative examples.

[0117]

[0118] The above results show that the open-graded colored asphalt wear layer of the present invention can achieve uniform dispersion of each raw material through appropriate raw material ratio, effectively improving the adhesion between the interface-reinforced asphalt and aggregates, inorganic raw materials, composite fibers and other raw materials. While achieving long-term permeability, it can avoid problems such as open-graded colored asphalt wear layer, scattering, discoloration, and brittle cracking, effectively improving its service life.

[0119] Compared to Example 1, Comparative Example 1 replaced the interface-reinforced decolorized asphalt with simple No. 70 matrix decolorized asphalt, without any reinforcement treatment on the decolorized asphalt. This resulted in insufficient adhesion between the decolorized asphalt and other raw materials, making the aggregates prone to scattering and falling off. It also reduced the water damage resistance of the mixture and affected the color retention of the open-graded colored asphalt wear layer. Similarly, compared to Example 1, Comparative Example 2 added only KH550 coupling agent during the preparation of interface-reinforced decolorized asphalt, Comparative Example 3 added only dodecylamine during the preparation of interface-reinforced decolorized asphalt, and Comparative Example 4 changed the mass ratio of KH550 coupling agent, dodecylamine, and ethanol. Different reinforcing raw materials had different reinforcing effects on the decolorized asphalt, thus affecting the performance of the decolorized asphalt in the mixture.

[0120] Compared with Example 1, the following changes also affected the performance of the prepared open-graded colored asphalt wear-resistant layer: Comparative Example 5 did not add composite fibers to the raw materials; Comparative Example 6 did not pretreat the polypropylene fibers but changed the length of the polypropylene fibers to 30 mm; Comparative Example 7 replaced the composite fibers with pretreated polypropylene fibers; and Comparative Example 8 replaced the composite fibers with pretreated lignin fibers. While the polypropylene fiber skeleton alone has high strength, the asphalt coating is insufficient, easily leading to the polypropylene fibers being "naked," resulting in significant leakage losses. Furthermore, the unit price of polypropylene fibers is relatively high, making it uneconomical. Using only pretreated lignin fibers has limited improvement on raw material performance, relying on the asphalt's own adhesive force, leading to insufficient control over properties such as scattering losses. This indicates that a simple fiber system cannot directly improve the bonding performance between asphalt and aggregates / fillers; otherwise, problems such as low stability, large scattering losses, and large segregation losses will occur. By pretreating the raw materials with appropriate materials, the adsorption performance of decolorized asphalt can be improved, making up for the insufficient bonding force of aggregates. At the same time, it can play a mechanical interlocking role, absorb load stress, and provide high-strength skeleton support, thereby improving the anti-scattering, anti-rutting, and anti-cracking properties of open-graded colored asphalt wear layers.

[0121] Compared with Example 1, the raw materials of Comparative Example 9 did not contain aggregate modifiers, and the aggregate modifiers of Comparative Example 10 did not contain sodium didodecyl phosphate, which affected the coating and adhesion properties between aggregates and raw materials such as asphalt and inorganic pigments, resulting in a decrease in the performance of open-graded colored asphalt wearing courses. This indicates that the present invention pre-treats the aggregates with aggregate modifiers before mixing them with inorganic pigments, which can prevent the aggregates from agglomerating and migrating, thus avoiding problems such as uneven color and rapid fading. Furthermore, the pre-coating can enhance the uniform dispersion and adhesion stability of inorganic pigments, allowing the freely dispersed pigments to adsorb asphalt, transforming the pigments from "inert fillers in the mixture" into "functional layers on the aggregate surface," reducing the influence of the asphalt-aggregate interface, and thereby improving the road performance of open-graded colored asphalt wearing courses.

[0122] The above description is only a preferred embodiment of the present invention and is 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 within the protection scope of the present invention.

Claims

1. A high color-stable, non-flying, sand-gravel type open-graded, colored asphalt wearing course, characterized in that, The raw materials include the following weight parts: interfacial strengthening decoloring asphalt 4.5-5.5 parts, coarse aggregate 75-83 parts, fine aggregate 7-11 parts, filler 0.3-0.5 parts, inorganic pigment 3-5 parts, composite fiber 0.2-0.3 parts, ultraviolet absorber 0.04-0.08 parts, aggregate modifier 0.1-0.25 parts; The preparation method of the interfacial strengthening decoloring asphalt is as follows: KH550 coupling agent and dodecylamine are added into ethanol to obtain a premix solution, then acetic acid is added to obtain an interfacial strengthening premix solution by stirring once, the decoloring asphalt is heated, then the interfacial strengthening premix solution is added dropwise to stir twice, and the interfacial strengthening decoloring asphalt is obtained; the mass ratio of the KH550 coupling agent, dodecylamine and ethanol is 1-2:1-2:3-6; The composite fiber includes pretreated polypropylene fiber and pretreated lignin fiber with a mass ratio of 1-2:2-3; the polypropylene fiber is a short fiber with a length of 6-8 mm; the pretreated polypropylene fiber is obtained by ultrasonic treatment of polypropylene fiber with polyetheramine; The preparation method of the pretreated lignin fiber is as follows: lignin fiber is put into a sodium hydroxide solution with a mass concentration of 4%-6% and treated at 50-60°C under stirring at a speed of 80-100 r / min for 10-15 min, then washed with water, dried, and the pretreated lignin fiber is obtained; The aggregate modifier includes didodecyl sodium phosphate, KH560 silane coupling agent and TTS titanate coupling agent with a mass ratio of 1-1.6:3-4:3-4.

2. The high color-stable, non-flying, sand-type open-graded, colored asphalt wearing course according to claim 1, characterized in that, The addition amount of acetic acid is 0.5%-1.0% of the mass of the premix solution; the addition amount of the interfacial strengthening premix solution is 2.5%-3.0% of the mass of the decoloring asphalt; and the decoloring asphalt is No. 70 base decoloring asphalt.

3. The high color-stable, non-flying, sand-type open-graded, colored asphalt wearing course of claim 1, wherein, The first stirring is performed at 25-35°C and a speed of 400-500 r / min for 15-20 min; the decoloring asphalt is heated to 120-130°C; and the second stirring is performed at a speed of 4000-5000 r / min for 25-30 min.

4. The high color-stable, non-flying, sand-type open-graded, colored asphalt wearing course of claim 1, wherein, The coarse aggregate is one or more of basalt and diabase; the fine aggregate is sandstone with a particle size less than 2.36 mm; more than 80% of the fine aggregate has 3 or more broken surfaces, and the specific surface area is greater than or equal to 600 cm 2 / g; and the filler is limestone powder.

5. The high color-stable, non-flying, sand-type open-graded, colored asphalt wearing course of claim 1 wherein, The inorganic pigment is one or more of red iron oxide, yellow iron oxide, black iron oxide, ultramarine blue, chromium oxide green, cadmium yellow, cobalt blue, molybdenum chromium red, iron blue, zinc yellow and cadmium sulfide.

6. The high color-stable, non-flying, sand-type open-graded, colored asphalt wearing course of claim 1 wherein, The mass ratio of the polypropylene fiber and polyetheramine is 8-10:1-1.

6.

7. The high color-stable, non-flying, sand-type open-graded, colored asphalt wearing course of claim 1 wherein, The ultraviolet absorber is one or more of ultraviolet absorbers UV-531, UV-329, UV-234 and UV-326.

8. The method of producing a high color-stable, non-flying, sand-gravel type open-graded colored asphalt wearing course according to any one of claims 1 to 7, characterized in that, The method includes the following steps: S1, a powder type ultraviolet absorber is added into naphthenic oil to mix into a slurry; didodecyl sodium phosphate in an aggregate modifier is added into dimethylformamide to stir and mix uniformly to obtain a mixed solution; S2, coarse aggregate and fine aggregate are heated to 160-170°C respectively and then put into a mixing drum, the mixed solution is sprayed to dry mix uniformly, then KH560 silane coupling agent and TTS titanate coupling agent in the aggregate modifier are sprayed to dry mix uniformly, and then inorganic pigment is added to mix again to obtain a premix; S3, dry mixing of the composite fiber to the premix, heating the interfacial strengthening decoloring pitch to 160-170℃ and spraying into the mixing cylinder, synchronously spraying the slurry obtained in step S1, completing the filler addition within 5s after the spraying of the interfacial strengthening decoloring pitch is completed, completing the production after wet mixing.

9. The method of claim 8, wherein the high color-stable, non-flying, sand grit type open-graded, colored asphalt wearing course is prepared by the steps of: The mass ratio of the ultraviolet absorber to naphthenic oil is 1-2:2-4; the mass ratio of the sodium dilauryl phosphate to dimethylformamide is 1-2:5-7; the dry mixing time is 10-20s and the rotating speed is 120-150r / min; the wet mixing time is 40-50s and the rotating speed is 300-400r / min.

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