Permeable colored asphalt concrete and preparation method thereof

Abstract

The present invention discloses a water-permeable colored asphalt concrete, which is obtained by compounding modified decolorized asphalt, water-permeable colored aggregate, inorganic colorant, auxiliary agent and additive; the water-permeable colored aggregate is a composite whisker-coated recycled aggregate, and the composite whiskers include at least titanium oxide whiskers. The water-permeable colored asphalt concrete of the present invention not only realizes resource recycling, but also achieves a significant improvement in performance. It has both excellent water permeability and mechanical properties, while ensuring its beautiful and durable color. The overall comprehensive performance and environmental adaptability are strong, and it can meet the long-term durability and stability of road paving materials in low-load scenarios such as campuses, parks, and scenic areas. The present invention also discloses a method for preparing water-permeable colored asphalt concrete.

Description

Technical Field

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

[0002] In modern urban road construction, asphalt concrete, as a common paving material, is widely used due to its advantages such as convenient construction and high cost-effectiveness. However, with the acceleration of urbanization and the improvement of environmental protection requirements, the shortcomings of traditional asphalt concrete have gradually become apparent. First, traditional asphalt concrete materials either perform poorly in terms of water permeability, unable to effectively alleviate urban waterlogging problems, unable to promote the natural infiltration of rainwater, affecting the balance of urban microclimate, or it is difficult to balance mechanical properties and water permeability, reducing the long-term service life of traditional asphalt concrete materials; especially in the face of extreme climate and environmental changes, traditional asphalt concrete has poor environmental adaptability and is prone to aging, cracking and other problems, affecting the service life of the road. Secondly, traditional asphalt concrete materials are either single in color or prone to color fading after long-term use under the influence of various harsh environmental weather conditions, which in turn affects the aesthetics and personalized expression of urban roads.

[0003] Therefore, developing an asphalt concrete that combines good water permeability with excellent mechanical properties, long-lasting color, and durability, while also being adaptable to a variety of environmental conditions, has become an important research direction for road paving materials. This present invention addresses the shortcomings of existing technologies through technological innovation, providing a new type of permeable colored asphalt concrete with improved overall performance and enhanced environmental adaptability. Summary of the Invention

[0004] In view of the above shortcomings of the existing technology, the present invention provides a permeable colored asphalt concrete to solve the shortcomings of traditional asphalt concrete in comprehensive performance and environmental adaptability such as permeability, mechanical properties, color aesthetics and durability.

[0005] In order to achieve the above objects, the technical solution adopted by the present invention is:

[0006] A permeable colored asphalt concrete is obtained by compounding modified decolorized asphalt, permeable colored aggregate, inorganic colorant, auxiliary agent and additive; the permeable colored aggregate is a composite whisker-coated recycled aggregate, and the composite whisker at least includes titanium oxide whiskers.

[0007] As a preferred technical solution, the mass ratio of the modified decolorized asphalt, permeable color aggregate, inorganic colorant, auxiliary agent and additive is 50-60:30-35:5-10:1-5:1-5.

[0008] As a preferred technical solution, the modified decolorized asphalt is made from decolorized asphalt. The decolorized asphalt is first heated and melted in a high-speed shearing machine, ultrasonically assisted stirred after adding a polymer modifier, and then modified by high-temperature melt mixing and extrusion in a screw extruder.

[0009] As a preferred technical solution, the polymer modifier is obtained by modifying monovinyl octasilsesquioxane grafted onto polyolefin. By adding the monovinyl octasilsesquioxane grafted onto polyolefin modifier, the modified decolorized asphalt of the present invention not only achieves enhanced bonding with aggregate, improved high-temperature stability, and improved low-temperature crack resistance, but also enhances hydrophobicity and aging resistance, providing a paving material with improved overall performance and greater environmental adaptability for permeable colored asphalt concrete.

[0010] As a preferred technical solution, the recycled aggregate is obtained by compounding colored quartz sand and / or colored glass beads with waste mineral sintered artificial aggregate products. This method, by using recycled aggregate obtained by compounding colored quartz sand and / or colored glass beads with waste mineral sintered artificial aggregate products, not only enhances the color diversity and aesthetics of concrete, but also achieves resource recycling and environmental sustainability. Furthermore, the coating of the composite whiskers enhances the mechanical properties and durability of the aggregate, bringing excellent overall performance to permeable colored asphalt concrete.

[0011] As a preferred technical solution, the waste mineral sintered artificial aggregate product is made by mixing at least one mineral granular raw material selected from waste ceramic tiles, feldspar, kaolin, and clay with a slurry and calcining it at high temperature.

[0012] As a preferred technical solution, the inorganic colorant is at least one of iron oxide red, iron oxide yellow, iron oxide black, ultramarine, cobalt blue, manganese violet, molybdate red, chromium oxide green, and carbon black.

[0013] As a preferred technical solution, the auxiliary agent is at least one of a dispersant, a compatibilizer, a surfactant, a stabilizer, and a coupling agent.

[0014] As a preferred technical solution, the additive is at least one of an anti-stripping agent, an anti-freeze-thaw agent, a water reducer, and a retarder.

[0015] Another aspect of the present invention is to provide a method for preparing the above-mentioned permeable colored asphalt concrete, the preparation method comprising the following steps:

[0016] S1: First, recycled aggregates of different gradations are ultrasonically dispersed in an ethanol aqueous solution, and then a tetrabutyl titanate precursor solution is added. The mixture is hydrolyzed at a pH of 3.8 to 5.3 for 1 to 2 days. Then, a zinc acetate precursor solution is added, and the pH is adjusted to 5.5 to 6.5. The hydrolysis reaction is continued for 0.5 to 2.5 hours. The mixture is heated to 70 to 90 degrees Celsius for 3 to 7 hours, and then the temperature is continued to be calcined for 15 to 30 minutes to obtain composite whisker-coated recycled aggregate, i.e., permeable colored aggregate.

[0017] S2: The permeable colored aggregate prepared in step S1 is evenly mixed with modified decolorized asphalt, inorganic colorant, auxiliary agent and additives in a mass ratio of 30-35:50-60:5-10:1-5:1-5 to obtain the permeable colored asphalt concrete.

[0018] The permeable colored asphalt concrete prepared by the present invention achieves significant performance improvements by compounding whiskers, particularly titanium oxide and zinc oxide whiskers, on the surface of recycled aggregates of different gradations. First, the titanium oxide whiskers provide high strength and modulus, enhancing the mechanical properties and durability of the aggregate and concrete. At the same time, these whiskers maintain the water permeability of the aggregate, helping to alleviate urban waterlogging and improve the microclimate. The photocatalytic properties of the titanium oxide whiskers promote the self-cleaning of the concrete surface, slow down the aging process, and maintain the bright color. In addition, the high reflectivity of the whiskers increases the reflective properties of the road surface, increases the glossiness of the color and improves the safety of pedestrians on the road surface, while their high thermal stability helps to reduce damage to the concrete in extreme temperatures.

[0019] The incorporation of zinc oxide whiskers further enhances the concrete's technical advantages. The antimicrobial properties of zinc oxide whiskers help maintain a hygienic concrete surface, reducing maintenance costs. They also absorb ultraviolet light, providing additional protection against aging and color degradation. Furthermore, zinc oxide whiskers further enhance chemical stability, making the concrete more adaptable to diverse environments.

[0020] Beneficial effects of the present invention:

[0021] The permeable colored asphalt concrete of the present invention not only achieves resource recycling but also achieves a significant improvement in performance by innovatively compounding whiskers, especially titanium oxide and zinc oxide whiskers, on the surface of recycled aggregate. This design not only enhances the mechanical properties and durability of concrete, but also maintains the water permeability of aggregate, helping to alleviate urban waterlogging and improve the microclimate. The photocatalytic properties of titanium oxide whiskers promote the self-cleaning of the concrete surface, slow down the aging process, and maintain the bright color. At the same time, the high reflectivity enhances the color gloss and road safety. In addition, the addition of modified decolorized asphalt and the high thermal stability of the composite whiskers improve the environmental adaptability and anti-aging performance of concrete, bringing excellent comprehensive performance to the paving material.

[0022] In general, the permeable colored asphalt concrete of the present invention not only has excellent permeability and mechanical properties, but also ensures its beautiful and durable color. It has strong overall comprehensive performance and environmental adaptability, and can meet the long-term durability and stability of pavement materials in low-load scenarios such as campuses, parks, and scenic spots. DETAILED DESCRIPTION

[0023] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are merely examples, and those skilled in the art may conceive of other obvious variations.

[0024] Example 1

[0025] The permeable colored asphalt concrete of this embodiment is obtained by compounding modified decolorized asphalt, permeable colored aggregate, inorganic colorant (iron oxide red and iron oxide black with a mass ratio of 92:8), auxiliaries and additives; the permeable colored aggregate is a composite whisker-coated recycled aggregate, and the composite whiskers include titanium oxide whiskers and zinc oxide whiskers.

[0026] The preparation method of the permeable colored asphalt concrete in this embodiment specifically comprises the following steps:

[0027] S1: First, 500g of recycled aggregates of different gradations were ultrasonically dispersed in 500mL of ethanol-water solution (the volume ratio of ethanol to water was 1:1), and then 100mL of 0.5mol / L tetrabutyl titanate precursor solution was added. The reaction was hydrolyzed at a pH of 4.0 for 1 day. Then, 50mL of 0.5mol / L zinc acetate precursor solution was added, the pH was adjusted to 5.5, the hydrolysis reaction was continued for 1.0 hour, the temperature was raised to 80℃ for reaction for 3 hours, and then the temperature was continued to be raised to 1050℃ for calcination heat treatment for 15min to obtain composite whisker-coated recycled aggregate, i.e., permeable colored aggregate; among them, the mass proportion of coarse aggregate of 26.5-40mm in the recycled aggregate was 20%, the mass proportion of medium aggregate of 19.0-26.5mm was 35%, and the mass proportion of fine aggregate of 4.75-19.0mm was 45%.

[0028] S2: The permeable colored aggregate prepared in step S1 is mixed evenly with modified decolorized asphalt, inorganic colorant (iron oxide red and iron oxide black in a mass ratio of 92:8), auxiliaries and additives in a mass ratio of 30:50:10:3:2 to obtain the permeable colored asphalt concrete.

[0029] The preparation of the recycled aggregate is as follows: First, 550g of high-alumina bauxite clinker is fully stirred with 450 ml of water until mixed evenly to form a uniform slurry without granular matter. Then, 200g of discarded ceramic tiles and 150g of discarded feldspar (total weight 350g) are selected and evenly mixed with the slurry prepared above to ensure that the mineral particles are evenly distributed in the slurry. Subsequently, the mixed mixture is placed in a high-temperature furnace and calcined at a temperature of 1100°C for 2 hours. This process requires ensuring that the temperature in the furnace is uniform and the calcination time is sufficient so that the mineral particles fully react with the high-alumina bauxite clinker in the slurry to form a stable sintered body. After calcination is completed, the sintered body is taken out and naturally cooled to room temperature. It is then ground using a grinder until the required particle size is reached, and sieved through a sieve to select a particle size range that meets the requirements to obtain a waste mineral sintered artificial aggregate product. Finally, the waste mineral sintered artificial aggregate product prepared above was compounded with 200 g of colored quartz sand to obtain the final recycled aggregate.

[0030] The modified decolorized asphalt is prepared as follows: First, 100g of polypropylene is grafted with 9.3g of monovinyl octasilsesquioxane (1,3,5,7,9,11,13-heptacyclopentyl-15-vinyl-octasilsesquioxane, CAS number 230316-02-6) under nitrogen protection; the reaction temperature is 150°C and the duration is 4 hours to ensure sufficient grafting reaction. Next, 1000g of decolorized asphalt is added as raw material and heated and melted in a high-speed shearing machine at 130°C until the decolorized asphalt is completely melted into a liquid state. Then, the prepared polymer modifier (i.e., the grafted polypropylene) is added to the melted decolorized asphalt, and an ultrasonic-assisted stirring device is activated to uniformly disperse the polymer modifier in the decolorized asphalt under the action of ultrasound. The stirring time is approximately 30 minutes. Finally, the evenly mixed modified asphalt was transferred to a screw extruder for further modification through high-temperature melt mixing and extrusion; the high-temperature melt temperature was set to 160°C and the screw speed was moderate to ensure that the modified asphalt could be fully mixed and reacted during the extrusion process.

[0031] The auxiliary agent consists of a dispersant (polyethylene glycol), a compatibilizer (maleic anhydride grafted polypropylene), a surfactant (sodium lauryl sulfate), a stabilizer (calcium stearate), and a coupling agent (KH-560) in a mass ratio of 2:3:1:2:2.

[0032] The additives consist of an anti-stripping agent (polyvinyl alcohol), an antifreeze-thaw agent (calcium chloride), a water reducer (sulfonated melamine formaldehyde resin), and a retarder (sodium gluconate) in a mass ratio of 5:4:5:3.

[0033] Example 2

[0034] The permeable colored asphalt concrete of this embodiment is obtained by compounding modified decolorized asphalt, permeable color aggregate, inorganic colorant (ultramarine and cobalt blue in a mass ratio of 6:4), auxiliaries and additives; the permeable color aggregate is a composite whisker-coated recycled aggregate, and the composite whiskers include titanium oxide whiskers and zinc oxide whiskers.

[0035] The preparation method of the permeable colored asphalt concrete in this embodiment specifically comprises the following steps:

[0036] S1: First, 500g of recycled aggregates of different gradations were ultrasonically dispersed in 500mL of ethanol-water solution (the volume ratio of ethanol to water was 1:1), and then 100mL of 0.5mol / L tetrabutyl titanate precursor solution was added. The reaction was hydrolyzed at a pH of 4.5 for 2 days. Then, 50mL of 0.5mol / L zinc acetate precursor solution was added, the pH was adjusted to 6.0, and the hydrolysis reaction was continued for 1.5 hours. The temperature was raised to 90℃ for reaction for 5 hours, and then the temperature was continued to be raised to 1050℃ for calcination heat treatment for 20min to obtain composite whisker-coated recycled aggregate, i.e., permeable colored aggregate; among them, the mass proportion of coarse aggregate of 26.5-40mm in the recycled aggregate was 25%, the mass proportion of medium aggregate of 19.0-26.5mm was 35%, and the mass proportion of fine aggregate of 4.75-19.0mm was 40%.

[0037] S2: The permeable colored aggregate prepared in step S1 is evenly mixed with modified decolorized asphalt, inorganic colorant (ultramarine and cobalt blue in a mass ratio of 6:4), auxiliaries and additives in a mass ratio of 32:55:8:3:2 to obtain the permeable colored asphalt concrete.

[0038] The preparation method of the recycled aggregate and modified decolorized asphalt is the same as that of Example 1, wherein, in the preparation process of the recycled aggregate, kaolin is selected instead of feldspar, and colored glass beads are selected instead of colored quartz sand; the raw materials and proportions of the auxiliary agents and additives are the same as those of Example 1.

[0039] Example 3

[0040] The permeable colored asphalt concrete of this embodiment is obtained by compounding modified decolorized asphalt, permeable color aggregate, inorganic colorant (chromium oxide green and cobalt blue in a mass ratio of 8:2), auxiliaries and additives; the permeable color aggregate is a composite whisker-coated recycled aggregate, and the composite whiskers include titanium oxide whiskers and zinc oxide whiskers.

[0041] The preparation method of the permeable colored asphalt concrete in this embodiment specifically comprises the following steps:

[0042] S1: First, 500g of recycled aggregates of different gradations were ultrasonically dispersed in 500mL of ethanol-water solution (the volume ratio of ethanol to water was 1:1), and then 100mL of 0.5mol / L tetrabutyl titanate precursor solution was added. The reaction was hydrolyzed at a pH of 5.3 for 2 days. Then, 50mL of 0.5mol / L zinc acetate precursor solution was added, the pH was adjusted to 6.5, and the hydrolysis reaction was continued for 2.5 hours. The temperature was raised to 90℃ for reaction for 7 hours, and then the temperature was continued to be raised to 1050℃ for calcination heat treatment for 30min to obtain composite whisker-coated recycled aggregate, i.e., permeable colored aggregate; among the recycled aggregates, the mass proportion of coarse aggregate of 26.5-40mm, the mass proportion of medium aggregate of 19.0-26.5mm, and the mass proportion of fine aggregate of 4.75-19.0mm were 30%.

[0043] S2: The permeable colored aggregate prepared in step S1 is mixed evenly with modified decolorized asphalt, inorganic colorant (chromium oxide green and cobalt blue in a mass ratio of 8:2), auxiliaries and additives in a mass ratio of 35:52:8:3:2 to obtain the permeable colored asphalt concrete.

[0044] The preparation method of the recycled aggregate and modified decolorized asphalt is the same as that of Example 1, wherein, in the preparation process of the recycled aggregate, clay is selected instead of feldspar, and 100g of colored quartz sand and 100g of colored glass beads are selected instead of 200g of colored quartz sand; the raw materials and proportions of the auxiliary agents and additives are the same as those of Example 1.

[0045] Example 4

[0046] The raw material composition and preparation steps of the permeable colored asphalt concrete in this embodiment are basically the same as those in Example 1, except that, in the preparation method of this embodiment, the inorganic colorant uses iron oxide red and manganese violet with a mass ratio of 1:9 instead of iron oxide red and iron oxide black with a mass ratio of 92:8.

[0047] Example 5

[0048] The raw material composition and preparation steps of the permeable colored asphalt concrete in this embodiment are basically the same as those in Example 1, except that, in the preparation method of this embodiment, the inorganic colorant uses iron oxide yellow and iron oxide red with a mass ratio of 95:5 instead of iron oxide red and iron oxide black with a mass ratio of 92:8.

[0049] Comparative Example 1

[0050] The raw material composition and preparation steps of the permeable colored asphalt concrete in this comparative example are basically the same as those in Example 1, except that, in the preparation method of this comparative example, recycled aggregate is directly used instead of composite whisker-coated recycled aggregate, that is, the recycled aggregate is not treated with composite whisker coating.

[0051] Comparative Example 2

[0052] The raw material composition and preparation steps of the permeable colored asphalt concrete in this comparative example are basically the same as those in Example 1, except that, in the preparation method of this comparative example, decolorized asphalt is directly used instead of modified decolorized asphalt, and the decolorized asphalt raw material is not modified with a polymer modifier.

[0053] The permeable colored asphalt concrete prepared in Examples 1 to 5 and Comparative Examples 1 to 2 was subjected to performance tests, and the performance results are shown in Table 1:

[0054] Among them, the water permeability test method: refer to the method described in "Permeable Pavement Bricks and Blocks" (GB / T 25993-2010) to conduct a penetration test to determine the water permeability coefficient of the sample material. The sample size is 100mm×100mm×500mm (length*width*height) to evaluate the water permeability of the sample.

[0055] Mechanical properties test method: Use a pressure testing machine to conduct compressive strength test, and refer to the "Standard for Test Methods of Mechanical Properties of Ordinary Concrete" (GB / T 50081-2002) for specific testing.

[0056] Color persistence test method: Color persistence is evaluated through accelerated aging tests. The specific test uses a xenon arc lamp for artificial accelerated aging tests. A 300W xenon arc lamp is used, the irradiation distance is 50cm, and the test time is 240 hours. A colorimeter is used to measure the Lab value under D65 light source, and the color difference ΔE is calculated. The color persistence of the sample is evaluated by the color difference (ΔE) before and after the test.

[0057] Durability testing method: Evaluation is conducted through freeze-thaw cycle testing, with a freezing temperature of -18°C and a thawing temperature of +20°C. The test is conducted in accordance with the "Test Methods for Durability of Concrete" (GB / T 50082-2009). Durability is evaluated based on the material's compressive strength retention after 100 cycles of testing.

[0058] Environmental adaptability test method: An artificial accelerated aging test is performed through a salt spray test (prepared with a 5% NaCl solution), and the compressive strength retention rate of the sample after continuous testing for 96 hours is evaluated.

[0059] Table 1

[0060]

[0061] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. Various changes and improvements are possible without departing from the spirit and scope of the present invention, and such changes and improvements fall within the scope of the invention as claimed.

Claims

1. A permeable colored asphalt concrete, characterized in that: The permeable colored asphalt concrete is obtained by compounding modified decolorized asphalt, permeable colored aggregate, inorganic colorant, auxiliary agent and additive; the permeable colored aggregate is a composite whisker-coated recycled aggregate, and the composite whiskers at least include titanium oxide whiskers; the modified decolorized asphalt is made from decolorized asphalt, which is first heated and melted in a high-speed shearing machine, and then ultrasonically assisted stirring is added and then modified in a screw extruder through high-temperature melt mixing and extrusion; the polymer modifier is obtained by modifying monovinyl octasilquioxane grafted onto polyolefin.

2. The permeable colored asphalt concrete according to claim 1, characterized in that: The mass ratio of the modified decolorized asphalt, the permeable color aggregate, the inorganic colorant, the auxiliary agent and the additive is 50-60:30-35:5-10:1-5:1-5.

3. The permeable colored asphalt concrete according to claim 1, characterized in that: The regenerated and recycled aggregate is obtained by compounding colored quartz sand and / or colored glass beads with waste mineral sintered artificial aggregate products.

4. The permeable colored asphalt concrete according to claim 3, characterized in that: The waste mineral sintered artificial aggregate product is made by mixing at least one mineral granular raw material selected from waste ceramic tiles, feldspar, kaolin and clay with slurry and calcining at high temperature.

5. The permeable colored asphalt concrete according to claim 1, characterized in that: The inorganic colorant is at least one of iron oxide red, iron oxide yellow, iron oxide black, ultramarine, cobalt blue, manganese violet, molybdate red, chromium oxide green, and carbon black.

6. The permeable colored asphalt concrete according to claim 1, characterized in that: The auxiliary agent is at least one of a dispersant, a compatibilizer, a surfactant, a stabilizer, and a coupling agent.

7. The permeable colored asphalt concrete according to claim 1, characterized in that: The additive is at least one of an anti-stripping agent, an anti-freezing and thawing agent, a water reducing agent, and a retarder.

8. A method for preparing permeable colored asphalt concrete according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: S1: First, recycled aggregates of different gradations are ultrasonically dispersed in an ethanol aqueous solution, and then a tetrabutyl titanate precursor solution is added. The mixture is hydrolyzed at a pH of 3.8 to 5.3 for 1 to 2 days. Then, a zinc acetate precursor solution is added, and the pH is adjusted to 5.5 to 6.

5. The hydrolysis reaction is continued for 0.5 to 2.5 hours. The mixture is heated to 70 to 90 degrees Celsius for 3 to 7 hours, and then the temperature is continued to be calcined for 15 to 30 minutes to obtain composite whisker-coated recycled aggregate, i.e., permeable colored aggregate. S2: The permeable colored aggregate prepared in step S1 is evenly mixed with modified decolorized asphalt, inorganic colorant, auxiliary agent and additives in a mass ratio of 30-35:50-60:5-10:1-5:1-5 to obtain the permeable colored asphalt concrete.

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