Carbon-based material loaded hydrotalcite synergistically modified composite rubber asphalt

Abstract

The invention discloses carbon-based material loaded hydrotalcite synergistically modified composite rubber asphalt which comprises the following components in percentage by mass: asphalt, rubber powder, a dispersing agent, a retarder, carbon-based material loaded hydrotalcite, an antioxidant and a heat stabilizer. The carbon-based material loaded hydrotalcite, the antioxidant and the heat stabilizer are compounded, so that the ultraviolet aging resistance, the oxidation aging resistance and the mechanical strength of the composite rubber asphalt can be remarkably improved, the limitation of a single modified material is effectively overcome, and the service life of an asphalt road is greatly prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to a modified asphalt and a preparation method thereof, in particular to a carbon-based material loaded hydrotalcite cooperatively modified composite rubber asphalt and a preparation method thereof. BACKGROUND

[0002] Composite rubber asphalt generally uses waste tire rubber powder as an important raw material, has economic and environmental benefits, and is an indispensable part of modern road pavement laying. However, there are some problems in the application process, such as easy cracking, extrusion deformation and other phenomena under high temperature conditions; under low temperature conditions, the road surface is prone to cracking due to the accumulation of thermal shrinkage stress; during service, heavy vehicles act on the asphalt pavement, causing serious rutting and indentation phenomena. Moreover, the rubber powder obtained from waste tires is vulcanized rubber, which releases toxic gases such as sulfur dioxide during high-temperature processing, causing harm to the environment. It is important to note that asphalt pavement is exposed to ultraviolet light for a long time, and the ultraviolet light energy at 290-420 nm is about 300-412 KJ / mol, which has a strong destructive ability on functional groups such as C=C and C=O. The composite rubber asphalt system does not solve the fundamental problem of aging caused by ultraviolet radiation.

[0003] Layered double hydroxides (LDH) are also known as hydrotalcite. The multi-layer structure of hydrotalcite can absorb and scatter ultraviolet light. Moreover, the interlayer ions of hydrotalcite absorb ultraviolet light and release the energy of ultraviolet light in the form of heat through electronic transition. For example, Lin Yanjun et al. (Invention Application Publication No. CN112778775 A; Invention Application Publication No. CN104725670 A) introduced hydrotalcite into asphalt, which significantly improved the ability of asphalt to resist ultraviolet aging. However, the strength of hydrotalcite materials is insufficient, and they are prone to agglomeration, which to some extent hinders the relaxation behavior of asphalt molecules at low temperatures, causing the modified asphalt to crack easily at low temperatures and lack mechanical strength. At the same time, hydrotalcite does not further solve the behavior of some functional groups in asphalt molecules absorbing heat and causing chemical bond rupture with oxygen due to thermal aging, which seriously restricts its application in actual engineering. SUMMARY

[0004] To address the technical problems of low-temperature cracking and insufficient mechanical strength in existing hydrotalcite-modified composite rubber asphalt, as well as its susceptibility to thermal aging, this invention provides a method for preparing carbon-based materials loaded with hydrotalcite for synergistic modification of composite rubber asphalt. Specifically, it uses carbon-based materials such as graphite, carbon fiber, and carbon nanotubes as carriers, and loads hydrotalcite onto these carriers. Combined with antioxidants such as N-(1-methylisopentyl)-N′-phenyl-p-phenylenediamine and heat stabilizers such as dioctyltin dilaurate, the composite rubber asphalt achieves high resistance to rutting and indentation even under repeated heavy vehicle traffic, and exhibits excellent resistance to UV aging and thermal aging under strong UV radiation.

[0005] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0006] A carbon-based material-loaded hydrotalcite-modified composite rubber asphalt, by mass fraction, comprises 70-80 parts asphalt, 15-25 parts rubber powder, 0.01-0.2 parts dispersant, 0.01-0.2 parts retarder, 1-10 parts carbon-based material-loaded hydrotalcite, 0.1-1 parts antioxidant, and 0.1-1 parts heat stabilizer.

[0007] Preferably, the dispersant is at least one of BYK-9077, BYK-354, oleamide, or erucamide; the retarder is at least one of naphthenic oil, bentonite, or polyethylene wax; and the heat stabilizer is at least one of tea polyphenols, barium stearate, magnesium stearate, dioctyltin dilaurate, or dioctyltin maleate.

[0008] Preferably, the antioxidant is at least one of catechol, dioctadecyl thiodipropionate, isoascorbic acid, N,N-diphenyl-p-phenylenediamine, diaryl-p-phenylenediamine, N-(1-methylisopentyl)-N′-phenyl-p-phenylenediamine (antioxidant 4020), N,N′-bis(2,4-dimethylphenyl)-p-phenylenediamine, or 4-isopropylaminodiphenylamine (antioxidant 4010NA).

[0009] Preferably, the dispersant is BYK-9077, the retarder is naphthenic oil, the antioxidant is N-(1-methylisopentyl)-N′-phenyl-p-phenylenediamine (anti-aging agent 4020), and the heat stabilizer is dioctyltin dilaurate.

[0010] Preferably, the preparation method of the carbon-based material-loaded hydrotalcite is as follows: carbon-based material, divalent metal salt, and trivalent metal salt are weighed in a molar ratio of 1~4:1~4:1. The weighed divalent and trivalent metal salts are dissolved in an alkaline solution. The weighed carbon-based material and the above solution are then poured into a sand mill for grinding and dispersion for 70-90 min. After shearing and dispersion to uniformity, the mixture is transferred to a reaction vessel lined with polytetrafluoroethylene material and subjected to a hydrothermal reaction at 120~180 ℃ for 18~36 h. After the reaction is completed, the product is filtered and dried at 50~70 ℃ for 22~26 h to obtain carbon-based material-loaded hydrotalcite. The obtained hydrotalcite is a layered double hydroxide (LDH). The alkaline solution is a sodium hydroxide solution, obtained by dissolving 0.05~0.07 mol of sodium hydroxide in 90~110 mL of deionized water.

[0011] Preferably, the carbon-based material is derived from biomass materials and their derivatives, specifically at least one of graphite, carbon fiber, carbon nanotubes, fullerene, graphene, graphene oxide, diamond, biochar, carbon black, glassy carbon, carbon aerogel, silicon carbide, graphynylene, graphite sheets, carbon nanoribbons, carbon nanowires, petroleum coke, corn stalks, bamboo, or bagasse.

[0012] Preferably, the divalent metal cation is Mg. 2+ Zn 2+ Ni 2+ or Cu 2+ One or more of the following; the trivalent metal cation is Al 3+ Fe 3+ Ga 3+ or Cr 3+ One or more of them.

[0013] Preferably, the carbon-based material is carbon fiber; the divalent metal cation is Mg. 2+ or Zn 2+ The trivalent metal cation is Al 3+ .

[0014] Preferably, the molar ratio of carbon-based material, divalent metal salt, and trivalent metal salt is 3:2:1.

[0015] The preparation method of carbon-based material-loaded hydrotalcite-synergistically modified composite rubber asphalt as described above includes the following steps:

[0016] (1) Weigh out 70-80 parts of asphalt, 15-25 parts of rubber powder, 0.01-0.2 parts of dispersant, 0.01-0.2 parts of retarder, 1-10 parts of carbon-based material loaded with hydrotalcite, 0.1-1 parts of antioxidant and 0.1-1 parts of heat stabilizer according to mass fraction;

[0017] (2) The asphalt obtained in step (1) is heated at 80~100℃ for 2~6 h to melt into a state with good fluidity. It is then transferred to a sand mill and the remaining raw materials obtained in step (1) are added and ground and dispersed until uniform. The mixture is then poured into a storage tank for expansion and aging for 4~6 h to obtain composite rubber asphalt modified with carbon-based material loaded with hydrotalcite.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] This invention utilizes carbon-based materials such as carbon fibers to load hydrotalcite (TLF). Long-chain carbon fibers, with their large specific surface area, provide active sites for the hydrotalcite, allowing it to grow on the carbon fiber surface and form a rigid composite material, thereby modifying composite rubber asphalt. The hydrotalcite loaded on the carbon fiber surface, with its inherent multi-layered structure, absorbs and scatters ultraviolet (UV) radiation. After absorbing UV radiation, the interlayer ions in the hydrotalcite dissipate the UV energy as heat through electron transitions. Combined with the heat stabilizer dioctyltin dilaurate, this further blocks the pathway of peroxide free radicals generated from weak bonds in the asphalt molecules due to long-term thermal aging, thus significantly improving the UV aging and heat aging resistance of the composite rubber asphalt. Simultaneously, carbon fibers themselves possess excellent flexibility, processability, high-temperature resistance, and extremely high tensile strength and elastic modulus. Carbon fiber molecules are tightly linked into a linear structure by van der Waals forces, and these lines interweave to form a network structure. This effectively inhibits the vulcanization phenomenon caused by vulcanized rubber and reduces the penetration of oxygen and moisture into the composite rubber asphalt. Meanwhile, the antioxidant 4020 can capture a small number of oxygen molecules that have penetrated into the composite rubber asphalt, preventing the contact between peroxide free radicals and oxygen molecules, and reducing the possibility of photo-oxidation reactions. This significantly improves the strength, hardness, high and low temperature resistance, and oxidation resistance of the composite rubber asphalt, compensating for the shortcomings of single-layer hydrotalcite modified rubber asphalt in these related properties. Therefore, by loading hydrotalcite onto carbon fibers, optimizing raw materials and processes, and supplementing with antioxidants and heat stabilizers, a composite rubber asphalt with high UV resistance and high strength has been successfully prepared. The preparation method is simple, environmentally friendly, and can significantly extend the service life of composite rubber asphalt pavements. Attached Figure Description

[0020] Figure 1 This is a SEM image of carbon fiber-loaded zinc-aluminum hydrotalcite (carbon fiber-ZnAl-LDH) prepared in Example 2.

[0021] Figure 2 This is a process flow diagram for preparing carbon-based materials loaded with hydrotalcite.

[0022] Figure 3 This is a schematic flowchart of the carbon-based material-loaded hydrotalcite synergistic modification of composite rubber asphalt and its preparation method. Detailed Implementation

[0023] The following is a detailed description of the specific embodiments in conjunction with the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Unless otherwise specified, the raw materials and reagents used in the examples are all commercially available. Asphalt was purchased from Maoming Weilong Petrochemical Co., Ltd., product model AH-70; rubber powder was purchased from Huayi Rubber Co., Ltd.; BYK-354 and BYK-9077 were purchased from Chengrui Chemical; naphthenic oil was purchased from Juyuan Polymer; bentonite was purchased from Shanghai Maclean Reagent; isoascorbic acid was purchased from Shanghai Maclean Reagent; antioxidant 4020 was purchased from Taisheng Chemical; dioctyl thiodipropionate was purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd.; barium stearate was purchased from Shanghai Maclean Reagent; February Dioctyltin cinnamate was purchased from Baiwei Chemical Reagents, and dioctyltin maleate was purchased from Guangzhou Shanghe Chemical Technology Co., Ltd.; carbon fiber was purchased from Weihai Guangwei Composite Materials Co., Ltd., carbon nanotubes were purchased from Shenzhen Suiheng Graphene Technology, and petroleum coke was purchased from Sinopec Beihai Refining & Chemical Co., Ltd.; magnesium sulfate, silicon carbide, aluminum sulfate octadecylhydrate, and aluminum nitrate nonahydrate were all purchased from Shanghai Maclean Reagents; zinc nitrate hexahydrate and zinc sulfate heptahydrate were purchased from Aladdin; and nickel nitrate hexahydrate was purchased from Chuandong Chemical.

[0024] Example 1

[0025] 1. The preparation method of carbon-based material supported magnesium-aluminum type hydrotalcite (carbon nanotube-MgAl-LDH) is as follows:

[0026] Carbon nanotubes, magnesium sulfate, and aluminum sulfate octadecyl hydrate were weighed in a molar ratio of 2:2:1. The magnesium sulfate and aluminum sulfate octadecyl hydrate were then dissolved in an alkaline sodium hydroxide solution. The carbon nanotubes and the sodium hydroxide solution containing the dissolved magnesium sulfate and aluminum sulfate octadecyl hydrate were then poured into a sand mill and ground for 70 min. The alkaline sodium hydroxide solution was prepared by mixing 0.06 mol of sodium hydroxide with 100 mL of deionized water. After uniform shearing and dispersion, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor liner and subjected to hydrothermal reaction at 120 °C for 36 h. After the reaction, the product was filtered and dried at 60 °C for 24 h to obtain carbon nanotube-supported magnesium-aluminum hydrotalcite (carbon nanotube-MgAl-LDH).

[0027] 2. A method for preparing a carbon-based material-loaded hydrotalcite-synergistically modified composite rubber asphalt, comprising the following steps:

[0028] (1) Weigh out 70 parts of asphalt, 15 parts of rubber powder, 0.01 parts of dispersant BYK-354, 0.01 parts of retarder naphthenic oil, 6 parts of carbon nanotube-MgAl-LDH prepared above, 0.1 parts of antioxidant dioctadecyl thiodipropionate, and 0.1 parts of heat stabilizer barium stearate according to the mass fraction.

[0029] (2) The asphalt obtained in step (1) is heated at 80 °C for 2 h to melt into a state with good fluidity and then transferred to a sand mill. At the same time, the remaining raw materials obtained in step (1) are ground and dispersed together until uniform, and then poured into a storage tank for expansion and aging for 6 h to obtain composite rubber asphalt modified by carbon nanotube-MgAl-LDH synergistic antioxidant and heat stabilizer and other additives, namely carbon-based material loaded with hydrotalcite synergistic modified composite rubber asphalt.

[0030] Example 2

[0031] 1. The preparation method of carbon-based material supported zinc-aluminum type hydrotalcite (carbon fiber-ZnAl-LDH) is as follows:

[0032] Carbon fibers, zinc nitrate hexahydrate, and aluminum nitrate nonahydrate were weighed in a molar ratio of 3:2:1. The zinc nitrate hexahydrate and aluminum nitrate nonahydrate were dissolved in an alkaline sodium hydroxide solution. The carbon fibers and the sodium hydroxide solution containing the dissolved zinc nitrate hexahydrate and aluminum nitrate nonahydrate were then poured into a sand mill and ground and dispersed for 80 min. The sodium hydroxide solution was prepared by mixing 0.06 mol sodium hydroxide with 100 mL deionized water. After uniform shear dispersion, the mixture was transferred to a reaction vessel lined with polytetrafluoroethylene (PTFE) and subjected to hydrothermal reaction at 160 °C for 24 h. After the reaction was completed, the product was filtered and dried at 60 °C for 24 h to obtain the corresponding carbon fiber-supported zinc-aluminum hydrotalcite (carbon fiber-ZnAl-LDH).

[0033] Figure 1 The image shows a SEM image of carbon fiber-ZnAl-LDH. As can be seen from the image, carbon fiber loaded with zinc-aluminum type hydrotalcite has been successfully prepared. The carbon fiber surface is loaded with a large amount of zinc-aluminum type hydrotalcite, and the distribution is uniform.

[0034] 2. A method for preparing a carbon-based material-loaded hydrotalcite-synergistically modified composite rubber asphalt, comprising the following steps:

[0035] (1) Weigh out 72 parts of asphalt, 21 parts of rubber powder, 0.1 parts of dispersant BYK-9077, 0.1 parts of retarder bentonite, 6 parts of carbon fiber-ZnAl-LDH prepared above, 0.4 parts of antioxidant 4020, and 0.4 parts of heat stabilizer dioctyltin dilaurate according to the mass fraction.

[0036] (2) The asphalt obtained in step (1) is heated at 90 °C for 5 h to melt into a state with good fluidity and then transferred to a sand mill. At the same time, the remaining raw materials obtained in step (1) are ground and dispersed together until uniform, and then poured into a storage tank for expansion and aging for 4 h to obtain composite rubber asphalt modified with carbon fiber-ZnAl-LDH synergistic antioxidant and heat stabilizer, i.e. carbon-based material loaded with hydrotalcite synergistic modified composite rubber asphalt.

[0037] Example 3

[0038] 1. The preparation method of carbon-based material supported zinc-aluminum type hydrotalcite (carbon fiber-ZnAl-LDH) is as follows:

[0039] Carbon fibers, zinc sulfate heptahydrate, and aluminum sulfate octahydrate were weighed in a molar ratio of 1:1:1. The zinc sulfate heptahydrate and aluminum sulfate octahydrate were then dissolved in an alkaline sodium hydroxide solution. The carbon fibers and the sodium hydroxide solution containing the dissolved zinc sulfate heptahydrate and aluminum sulfate octahydrate were then poured into a sand mill and ground for 90 min. The sodium hydroxide solution was prepared by mixing 0.06 mol of sodium hydroxide with 100 mL of deionized water. After uniform shearing and dispersion, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor liner and subjected to a hydrothermal reaction at 180 °C for 18 h. After the reaction, the product was filtered and dried at 60 °C for 24 h to obtain the corresponding carbon fiber-supported zinc-aluminum hydrotalcite (carbon fiber-ZnAl-LDH).

[0040] 2. A method for preparing a carbon-based material-loaded hydrotalcite-synergistically modified composite rubber asphalt, comprising the following steps:

[0041] (1) Weigh out 80 parts of asphalt, 25 parts of rubber powder, 0.2 parts of dispersant BYK-9077, 0.2 parts of retarder naphthenic oil, 6 parts of carbon fiber-ZnAl-LDH prepared above, 1 part of antioxidant isoascorbic acid, and 1 part of heat stabilizer dioctyltin dilaurate according to the mass fraction.

[0042] (2) The asphalt obtained in step (1) is heated at 90 °C for 5 h to melt into a state with good fluidity and transferred to a sand mill; at the same time, the remaining raw materials obtained in step (1) are ground and dispersed together until uniform, and then poured into a storage tank for expansion and aging for 4 h to obtain composite rubber asphalt modified with carbon fiber-ZnAl-LDH synergistic antioxidant and heat stabilizer and other additives, namely carbon-based material loaded with hydrotalcite synergistic modified composite rubber asphalt.

[0043] Example 4

[0044] 1. The preparation method of carbon-based material-supported nickel-aluminum type hydrotalcite (silicon carbide-NiAl-LDH) is as follows:

[0045] Silicon carbide, nickel nitrate hexahydrate, and aluminum nitrate nonahydrate were weighed in a molar ratio of 4:4:1. The weighed nickel nitrate hexahydrate and aluminum nitrate nonahydrate were then dissolved in an alkaline sodium hydroxide solution. The silicon carbide was then added to the alkaline sodium hydroxide solution containing zinc sulfate heptahydrate and aluminum sulfate octadecahydrate and ground and dispersed for 80 min in a sand mill. The alkaline sodium hydroxide solution was prepared by mixing 0.06 mol sodium hydroxide with 100 mL deionized water. After uniform shear dispersion, the mixture was transferred to a PTFE-lined reactor and hydrothermally reacted at 120 ℃ for 36 h. After the reaction, the product was filtered and dried at 60 ℃ for 24 h to obtain the corresponding silicon carbide-supported nickel-aluminum type layered double hydroxide (silicon carbide-NiAl-LDH).

[0046] 2. A method for preparing a carbon-based material-loaded hydrotalcite-synergistically modified composite rubber asphalt, comprising the following steps:

[0047] (1) Weigh out 72 parts of asphalt, 21 parts of rubber powder, 0.1 parts of dispersant BYK-354, 0.1 parts of retarder naphthenic oil, 6 parts of silicon carbide-NiAl-LDH prepared above, 0.4 parts of antioxidant isoascorbic acid, and 0.4 parts of heat stabilizer dioctyl tin maleate according to the mass fraction.

[0048] (2) The asphalt obtained in step (1) is heated at 100 °C for 6 h to melt into a state with good fluidity and transferred to a sand mill; at the same time, the remaining raw materials obtained in step (1) are ground and dispersed together until uniform, and then poured into a storage tank for expansion and aging for 4 h to obtain composite rubber asphalt modified by silicon carbide-NiAl-LDH synergistic antioxidant and heat stabilizer, namely carbon-based material loaded with hydrotalcite synergistic modified composite rubber asphalt.

[0049] Example 5

[0050] 1. The preparation method of carbon-based material supported zinc-aluminum type hydrotalcite (petroleum coke-ZnAl-LDH) is as follows:

[0051] Petroleum coke, zinc nitrate hexahydrate, and aluminum nitrate nonahydrate were weighed in a molar ratio of 3:2:1. The zinc nitrate hexahydrate and aluminum nitrate nonahydrate were then dissolved in an alkaline sodium hydroxide solution. The petroleum coke and the sodium hydroxide solution containing the dissolved zinc nitrate hexahydrate and aluminum nitrate nonahydrate were then poured into a sand mill and ground for 80 min. The sodium hydroxide solution was prepared by mixing 0.06 mol of sodium hydroxide with 100 mL of deionized water. After uniform shearing and dispersion, the mixture was transferred to a PTFE-lined reactor and hydrothermally reacted at 160 ℃ for 24 h. After the reaction, the product was filtered and dried at 60 ℃ for 24 h to obtain the corresponding petroleum coke-supported zinc-aluminum type hydrotalcite (petroleum coke-ZnAl-LDH).

[0052] 2. A method for preparing a carbon-based material-loaded hydrotalcite-synergistically modified composite rubber asphalt, comprising the following steps:

[0053] (1) Weigh out 72 parts of asphalt, 21 parts of rubber powder, 0.1 parts of dispersant BYK-9077, 0.1 parts of retarder bentonite, 1 part of petroleum coke-ZnAl-LDH prepared above, 0.4 parts of antioxidant 4020, and 0.4 parts of heat stabilizer dioctyltin dilaurate according to the mass fraction.

[0054] (2) The asphalt obtained in step (1) is heated at 90 °C for 5 h to melt into a state with good fluidity and transferred to a sand mill; at the same time, the remaining raw materials obtained in step (1) are ground and dispersed together until uniform, and then poured into a storage tank for expansion and aging for 4 h to obtain composite rubber asphalt modified by petroleum coke-ZnAl-LDH synergistic antioxidant and heat stabilizer, namely carbon-based material loaded with hydrotalcite synergistic modified composite rubber asphalt.

[0055] Example 6

[0056] 1. The preparation method of carbon-based material supported zinc-aluminum type hydrotalcite (carbon fiber-ZnAl-LDH) is as follows:

[0057] Carbon fibers, zinc nitrate hexahydrate, and aluminum nitrate nonahydrate were weighed in a molar ratio of 3:2:1. The zinc nitrate hexahydrate and aluminum nitrate nonahydrate were then dissolved in an alkaline sodium hydroxide solution. The carbon fibers and the sodium hydroxide solution containing the dissolved zinc nitrate hexahydrate and aluminum nitrate nonahydrate were then poured into a sand mill and ground for 80 min. The sodium hydroxide solution was prepared by mixing 0.06 mol of sodium hydroxide with 100 mL of deionized water. After uniform shearing and dispersion, the mixture was transferred to a polytetrafluoroethylene (PTFE) reactor liner and subjected to hydrothermal reaction at 160 °C for 24 h. After the reaction, the product was filtered and dried at 60 °C for 24 h to obtain the corresponding carbon fiber-supported zinc-aluminum hydrotalcite (carbon fiber-ZnAl-LDH).

[0058] 2. A method for preparing a carbon-based material-loaded hydrotalcite-synergistically modified composite rubber asphalt, comprising the following steps:

[0059] (1) Weigh out 72 parts of asphalt, 21 parts of rubber powder, 0.1 parts of dispersant BYK-9077, 0.1 parts of retarder bentonite, 10 parts of carbon fiber-ZnAl-LDH prepared above, 0.4 parts of antioxidant 4020, and 0.4 parts of heat stabilizer dioctyltin dilaurate according to the mass fraction.

[0060] (2) The asphalt obtained in step (1) is heated at 90 °C for 5 h to melt into a state with good fluidity and transferred to a sand mill; at the same time, the remaining raw materials obtained in step (1) are ground and dispersed together until uniform, and then poured into a storage tank for expansion and aging for 4 h to obtain composite rubber asphalt modified by carbon fiber-ZnAl-LDH synergistic antioxidant and heat stabilizer, namely carbon-based material loaded with hydrotalcite synergistic modification composite rubber asphalt.

[0061] Comparative Example 1

[0062] In the preparation of a carbon-based material loaded with hydrotalcite synergistically modified composite rubber asphalt, "carbon-based material loaded with hydrotalcite" is not added, and the remaining operations are the same as "2. A method for preparing a carbon-based material loaded with hydrotalcite synergistically modified composite rubber asphalt" in Example 2.

[0063] Comparative Example 2

[0064] In the preparation process of a carbon-based material loaded with hydrotalcite synergistically modified composite rubber asphalt, "carbon-based material loaded with hydrotalcite" is replaced with "hydrotalcite" added, and the remaining operations are the same as "2. A method for preparing a carbon-based material loaded with hydrotalcite synergistically modified composite rubber asphalt" in Example 2.

[0065] Comparative Example 3

[0066] In the preparation process of a carbon-based material loaded with hydrotalcite synergistically modified composite rubber asphalt, "carbon-based material loaded with hydrotalcite" is replaced with "carbon fiber", and the remaining operations are the same as "2. A method for preparing a carbon-based material loaded with hydrotalcite synergistically modified composite rubber asphalt" in Example 2.

[0067] Comparative Example 4

[0068] In the preparation process of a carbon-based material loaded with hydrotalcite synergistically modified composite rubber asphalt, "antioxidant 4020" is not added, and the remaining operations are the same as "2. Preparation method of a carbon-based material loaded with hydrotalcite synergistically modified composite rubber asphalt" in Example 2.

[0069] Comparative Example 5

[0070] In the preparation of a carbon-based material-loaded hydrotalcite-modified composite rubber asphalt, the heat stabilizer "dioctyltin dilaurate" is not added, and the remaining operations are the same as "2. A method for preparing a carbon-based material-loaded hydrotalcite-modified composite rubber asphalt" in Example 2.

[0071] The products prepared above were tested using instruments such as an asphalt softening point tester, an asphalt penetration tester, a low-temperature ductility tester, and a rotating thin film oven, in accordance with national standards such as GB / T 4507-2014, GB / T 4509-2010, GB / T 4508-2010, and GB / T 5304-2001. The specific performance is shown in Table 1.

[0072] Table 1 shows that, comparing the composite rubber asphalts prepared in Examples 1-6 and Comparative Examples 1-5, the composite rubber asphalt with added carbon fiber-loaded hydrotalcite, antioxidants such as antioxidant 4020, and heat stabilizers such as dioctyltin dilaurate exhibits the best overall performance. Specifically, the rubber composite modified asphalt in Comparative Example 2, which only added hydrotalcite, showed improved performance in terms of mass loss and penetration ratio after the Rotating Thin Film Oven Test (RTFOT), compared to the composite rubber asphalt modified with carbon fiber alone. However, its ductility (cm) at 5℃ was lower, indicating insufficient resistance to low-temperature cracking. Compared with the composite rubber asphalt with carbon fiber added, the modified softening point and ductility (cm) at 5℃ showed a significant improvement compared with the composite rubber asphalt modified with hydrotalcite alone, indicating that it has higher resistance to rutting and low-temperature cracking. However, the composite rubber asphalt modified with carbon fiber alone showed higher mass loss and lower penetration after the rotating thin film oven test (RTFOT), indicating that it was severely affected by short-term thermal aging and strong ultraviolet aging, which seriously affected the service life of the composite rubber asphalt. In Examples 1 to 6, especially the use of carbon fiber to load hydrotalcite and the synergistic modification of composite rubber asphalt with antioxidants and heat stabilizers, it can be found that: (1) The linear structure of carbon fiber is interwoven into a network structure, which can provide many active sites to load hydrotalcite and form a composite material, which can maintain the strength properties of carbon fiber itself and introduce the high-efficiency ultraviolet resistance function of hydrotalcite. (2) As the amount of carbon fiber-loaded hydrotalcite added gradually increases, the hardness and strength of the composite rubber asphalt are further improved, thereby improving the wear resistance of the composite rubber asphalt and improving its resistance to rutting, indentation and high and low temperature strain. (3) Antioxidants capture oxygen from the air into the asphalt molecules, reducing thermal oxidation and aging; heat stabilizers assist hydrotalcite in transferring heat and improve the thermal stability of the modified composite rubber asphalt.

[0073] Table 1 Product Technical Specifications

[0074]

[0075] The products prepared above were tested according to standards such as JTG E20-2011 using instruments such as a Marshall stability tester, a rutting tester, and a universal testing machine. Table 2 shows that, in terms of dynamic stability at 60 ℃ and 0.7 MPa, residual Marshall stability after immersion in water, low-temperature breaking tensile strength, and stiffness modulus, the performance of the carbon-based material-loaded hydrotalcite-modified composite rubber asphalt mixtures involved in Examples 1-6 is far superior to that of the composite rubber asphalt mixtures involved in Comparative Examples 1-5. This indicates a significant improvement in high-temperature rutting resistance, low-temperature crack resistance, waterproof performance, and durability. This is because the high-strength carbon fibers firmly anchor the hydrotalcite to its surface, solving the problem of insufficient strength properties of hydrotalcite. Furthermore, hydrotalcite, as a highly efficient UV absorber, further addresses the problem of cracking in the composite rubber asphalt due to UV aging. Compared with Comparative Example 2, the introduction of carbon fibers effectively compensates for the deficiency in low-temperature toughness of hydrotalcite-modified composite rubber asphalt. Furthermore, by simultaneously introducing antioxidants and heat stabilizers, the problem of thermal aging caused by the easy thermal expansion of asphalt when hydrotalcite shields and absorbs ultraviolet rays has been further solved.

[0076] Table 2 Performance Indicators of the Mixture

[0077]

[0078] The products prepared above were tested according to standards such as JTG E20-2011 using instruments such as a Brookfield viscometer and an asphalt softening point tester. Table 3 shows that, in terms of viscosity aging index (VAI) and softening point increment (ΔS), compared to Comparative Example 3, the composite rubber asphalt modified with carbon fiber-loaded hydrotalcite exhibited significantly reduced VAI and ΔS due to the high UV resistance of the hydrotalcite molecules on the carbon fiber surface. This solved the fundamental problem of insufficient UV aging resistance in carbon fiber-modified composite rubber asphalt. Furthermore, the addition of hydrotalcite to the heat stabilizer and antioxidant further enhances the protection of weak chemical bonds in the asphalt molecules, improving overall weather resistance.

[0079] Table 3 Anti-aging properties

[0080]

[0081] This invention provides a novel approach for low-cost, high-strength modified composite rubber asphalt. Specifically, it utilizes carbon-based materials such as carbon fiber to load hydrotalcite, along with antioxidants like antioxidant 4020 and heat stabilizers such as dioctyltin dilaurate to modify the composite rubber asphalt. Hydrotalcite enhances the composite rubber asphalt's ability to shield and absorb ultraviolet radiation; carbon-based materials like carbon fiber inhibit high-temperature vulcanization and improve its resistance to low-temperature cracking. However, the composite rubber asphalt, when exposed to ultraviolet radiation, generates superoxide free radicals, leading to a series of highly destructive photo-oxidative aging problems. The antioxidants and heat stabilizers primarily address the photo-oxidative aging issues that hydrotalcite cannot resolve, mainly by blocking the generation of highly destructive superoxide free radicals during thermal aging, thus interrupting free radical chain reactions and improving stability. The effects of these materials are not independent but intertwined, maximizing the synergistic effect. Therefore, combining carbon-based materials with hydrotalcite, antioxidants, and heat stabilizers can significantly improve the UV aging resistance, oxidative aging resistance, and mechanical strength of composite rubber asphalt, effectively overcoming the limitations of single modified materials and thus greatly extending the service life of asphalt roads.

[0082] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A carbon-based material loaded hydrotalcite synergistically modified composite rubber asphalt, characterized in that: The components include, by mass fraction, 70-80 parts of asphalt, 15-25 parts of rubber powder, 0.01-0.2 parts of dispersant, 0.01-0.2 parts of retarder, 1-10 parts of carbon-based material loaded hydrotalcite, 0.1-1 part of antioxidant and 0.1-1 part of heat stabilizer.

2. The carbon-based material supported hydrotalcite synergistically modified composite rubber asphalt according to claim 1, characterized in that: The dispersant is at least one of BYK-9077, BYK-354, oleic acid amide or erucic acid amide; the retarder is at least one of naphthenic oil, bentonite or polyethylene wax; and the heat stabilizer is at least one of tea polyphenol, barium stearate, magnesium stearate, dioctyltin dilaurate or dioctyltin maleate.

3. The carbon-based material supported hydrotalcite synergistically modified composite rubber asphalt according to claim 1, characterized in that: The antioxidant is at least one of catechol, dioctylthiodipropionate, erythorbic acid, N,N-diphenyl-p-phenylenediamine, diaryl-p-phenylenediamine, N-(1-methylisopentyl)-N'-phenyl-p-phenylenediamine, N,N'-bis(2,4-dimethylphenyl)-p-phenylenediamine or 4-isopropylaminodiphenylamine (antioxidant 4010NA).

4. The carbon-based material supported hydrotalcite synergistically modified composite rubber asphalt according to claim 1, characterized in that: The dispersant is BYK-9077, the retarder is naphthenic oil, the antioxidant is N-(1-methylisopentyl)-N'-phenyl-p-phenylenediamine and the heat stabilizer is dioctyltin dilaurate.

5. The carbon-based material supported hydrotalcite synergistically modified composite rubber asphalt of claim 1, wherein: The preparation method of the carbon-based material loaded hydrotalcite comprises the following steps: taking carbon-based material, divalent metal salt and trivalent metal salt according to a molar ratio of 1-4:1-4:1, dissolving the obtained divalent metal salt and trivalent metal salt in an alkaline solution, grinding and dispersing the carbon-based material and the solution together for 70-90 min, transferring the mixture to a reaction kettle, carrying out hydrothermal reaction at 120-180 ℃ for 18-36 h, filtering the product, drying the product at 50-70 ℃ for 22-26 h, and obtaining the carbon-based material loaded hydrotalcite.

6. The carbon-based material supported hydrotalcite synergistically modified composite rubber asphalt according to claim 5, characterized in that: The carbon-based material is derived from at least one of biomass material and its derivatives, specifically, graphite, carbon fiber, carbon nanotube, fullerene, graphene, graphene oxide, diamond, biochar, carbon black, glassy carbon, carbon aerogel, silicon carbide, graphyne, graphite sheet, carbon nanobelt, carbon nanowire, petroleum coke, corn stalk, bamboo or sugarcane residue.

7. The carbon-based material supported hydrotalcite synergistically modified composite rubber asphalt of claim 5, wherein: the divalent metal cation is one or several of Mg 2+ , Zn 2+ , Ni 2+ or Cu 2+ ; the trivalent metal cation is one or several of Al 3+ , Fe 3+ , Ga 3+ or Cr 3+ .

8. The carbon-based material supported hydrotalcite synergistically modified composite rubber asphalt of claim 5, wherein: The carbon-based material is carbon fiber; the divalent metal cation is Mg 2+ or Zn 2+ , and the trivalent metal cation is Al 3+ .

9. The carbon-based material supported hydrotalcite synergistically modified composite rubber asphalt of claim 5, wherein: The molar ratio of the carbon-based material, divalent metal salt and trivalent metal salt is 3:2:

1.

10. The preparation method of the carbon-based material loaded hydrotalcite synergistically modified composite rubber asphalt according to any one of claims 1-9, characterized in that, The method comprises the following operation steps: (1) taking, by mass fraction, 70-80 parts of asphalt, 15-25 parts of rubber powder, 0.01-0.2 parts of dispersant, 0.01-0.2 parts of retarder, 1-10 parts of carbon-based material loaded hydrotalcite, 0.1-1 part of antioxidant and 0.1-1 part of heat stabilizer; (2) heating the obtained asphalt in step (1) at 80-100 ℃ for 2-6 h to melt into a state with good fluidity, transferring the asphalt to a sand mill, grinding and dispersing the remaining raw materials in step (1) together until uniform, pouring the mixture into a storage tank, expanding and aging the mixture in the storage tank for 4-6 h, and obtaining the carbon-based material loaded hydrotalcite synergistically modified composite rubber asphalt.

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