Solid waste rubber powder modified emulsified asphalt for permeable pavement and preparation method of solid waste rubber powder modified emulsified asphalt

Abstract

The invention relates to solid waste rubber powder modified emulsified asphalt for a permeable pavement and a preparation method thereof, and relates to the technical field of asphalt. The modified asphalt is prepared from the following components in parts by mass: 60 to 70 parts of asphalt, 15 to 25 parts of solid waste rubber powder, 4 to 6 parts of poly (4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid), 1.5 to 3.5 parts of carbon fiber, 3 to 5 parts of an emulsifier, 0.5 to 1.5 parts of a penetration enhancer, 0.3 to 0.8 part of a stabilizer and 0.2 to 0.6 part of an anti-aging agent. The preparation method comprises the following steps: heating asphalt until the asphalt is molten, adding solid waste rubber powder, poly (4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) and carbon fibers, and stirring to obtain a mixture; dispersing an emulsifier into a solvent to obtain an emulsifier solution; adding the mixture into an emulsifier solution, shearing and dispersing, sequentially adding an osmotic regulator, a stabilizer and an anti-aging agent, and stirring to obtain the solid waste rubber powder modified emulsified asphalt for the permeable pavement. The rubber powder modified emulsified asphalt has the effect of improving the compatibility of the rubber powder modified emulsified asphalt, and the asphalt has good high and low temperature performance and storage stability.

Description

Technical Field

[0001] This application relates to the technical field of asphalt, and particularly to a solid waste rubber powder modified emulsified asphalt for permeable pavement and its preparation method. Background Art

[0002] In recent years, the popularization of permeable pavement has provided an effective way to alleviate urban waterlogging and the heat island effect. The performance of the core material, modified emulsified asphalt, directly affects the water permeability and durability of the pavement. Traditional modified emulsified asphalt mostly uses SBS or latex as modifiers. Although it can improve the adhesion of asphalt, it has the defects of high raw material cost and insufficient environmental protection. Some studies have tried to use waste rubber powder as a modifier, but the compatibility between solid waste rubber and asphalt components is poor, and it is difficult to achieve sufficient swelling and dispersion of rubber particles by conventional mechanical stirring methods, resulting in poor storage stability of the modified emulsified asphalt and problems such as uneven demulsification and clogging of permeable pores during construction.

[0003] In the prior art, the preparation process of rubber powder modified emulsified asphalt mostly follows high-temperature shearing or colloid mill grinding. Although these methods can refine rubber particles, they cannot solve the problem of weak interfacial bonding caused by the inertness of the rubber powder surface. During storage, rubber particles are prone to separate from the asphalt phase, causing delamination and skinning of the emulsification system, which directly affects the spraying uniformity during construction and the structural strength of the formed pavement, so it needs to be improved. Summary of the Invention

[0004] In order to improve the compatibility of solid waste rubber powder modified emulsified asphalt, this application provides a solid waste rubber powder modified emulsified asphalt for permeable pavement and its preparation method.

[0005] A solid waste rubber powder modified emulsified asphalt for permeable pavement and its preparation method provided by this application adopt the following technical solutions: In the first aspect, a solid waste rubber powder modified emulsified asphalt for permeable pavement provided by this application adopts the following technical solution: A solid waste rubber powder modified emulsified asphalt for permeable pavement, comprising the following components in parts by mass: Asphalt 60 - 70 parts Solid waste rubber powder 15 - 25 parts Poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) 4 - 6 parts Carbon fiber 1.5 - 3.5 parts Emulsifier 3 - 5 parts Penetration regulator 0.5 - 1.5 parts Stabilizer 0.3 - 0.8 parts Anti-aging agent 0.2 - 0.6 parts.

[0006] Solid waste rubber powder can swell in asphalt, and its flexible chain segments are intertwined with asphalt molecules to improve the cohesion and flexibility of asphalt; poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) has a rigid rod-like molecular structure, and polar groups such as hydroxyl groups on its molecular chain can form hydrogen bond interactions and π-π stacking interactions with polar components such as aromatics and resins in asphalt, thereby enhancing the intermolecular force with asphalt. At the same time, poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) can form a bridge between rubber powder and asphalt. Its rigid chain segments are inserted into the cross-linked network of rubber powder and intertwined with the flexible chain segments of rubber powder, while the other end is tightly bound to asphalt molecules to form a physical cross-linked network; this network structure effectively restricts the relative movement of rubber powder and asphalt molecules, makes the two evenly dispersed, significantly improves the overall compatibility, and reduces the phase separation tendency caused by the density and polarity differences of components; carbon fiber, with its high specific surface area and excellent dispersibility, is evenly distributed in the system to further strengthen the binding force between components and stabilize the dispersed structure; solid waste rubber powder and carbon fiber construct a porous network skeleton inside asphalt, and the penetration regulator helps to optimize the internal pore structure, enabling asphalt to form continuous and uniform water-permeable channels; the stabilizer and anti-aging agent act synergistically to ensure the long-term stability of asphalt while maintaining the integrity of the pore structure, ensuring that the permeable pavement always has good water-permeable effect during long-term use, and realizing the efficient management and utilization of urban rainwater.

[0007] Preferably, the solid waste rubber powder is subjected to modification treatment and is prepared by the following steps: (1) Pretreat the solid waste rubber powder, screen and remove impurities, and then ball-mill it to obtain pretreated rubber powder; (2) Mix and disperse the pretreated rubber powder and tannic acid in a solvent and stir. After filtration and drying, obtain preliminarily modified rubber powder; melt-blend the above-prepared preliminarily modified rubber powder and polyhydroxyalkanoate, extrude, cool and pelletize, and perform aging treatment to obtain compatibilized modified rubber powder.

[0008] In the pretreatment step, screening and impurity removal can remove impurities in the rubber powder to avoid the influence of impurities on the compatibility with asphalt; ball milling treatment can refine the particle size of the rubber powder, increase the specific surface area, and make it more easily dispersed in asphalt; mixing and stirring the pretreated rubber powder and tannic acid in a solvent, a large number of phenolic hydroxyl groups contained in tannic acid can react chemically or form hydrogen bonds with the surface active groups of the rubber powder, improving the surface polarity of the rubber powder and making it better combined with polar substances in asphalt; at the same time, tannic acid, as a natural antioxidant, can delay the aging of the rubber powder; melting and blending the preliminarily modified rubber powder with polyhydroxyalkanoate, polyhydroxyalkanoate has good biocompatibility and biodegradability, and its molecular chain can entangle with the molecular chain of the rubber powder to form a transition layer at the interface, reducing the interfacial tension between the two phases and improving the compatibility of the rubber powder and asphalt; extrusion, cooling, pelletizing and aging treatment make the structure of the blending system more stable, enable the rubber powder to be better dispersed in the modified emulsified asphalt for permeable pavement, reduce phase separation, enhance the flexibility and elasticity of asphalt, further optimize the high and low temperature performance and permeable performance of the permeable pavement, and extend its service life.

[0009] Preferably, in the step (2), the mass ratio of the pretreated rubber powder, polyhydroxyalkanoate and tannic acid is 1:(0.1 - 0.2):0.02.

[0010] The compatibilizing and modifying rubber powder prepared according to the above mass ratio has good compatibility and can effectively improve the high and low temperature performance and permeable performance of asphalt.

[0011] Preferably, the poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) is subjected to modification treatment and is prepared by the following steps: Mix poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid), polyethylene glycol and maleic anhydride, conduct a melting and blending reaction to obtain a blend, and cool and dry the blend to obtain a modified liquid crystal polymer.

[0012] Poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid), as a liquid crystal polymer, has strong self-rigidity. Polyethylene glycol has good flexibility and amphiphilicity, and its long-chain molecules can interpenetrate between the rigid molecular chains of poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid), reducing the overall glass transition temperature of the polymer, enhancing its flexibility and fluidity, and further improving the interfacial contact with asphalt. Maleic anhydride contains active anhydride groups. During the melt blending process, it can react with the hydroxyl groups on the molecular chains of poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid), and can also react with the hydroxyl groups of polyethylene glycol, forming chemical bond connections among the three, constructing a bridge structure, enhancing the intermolecular interaction force, making the modified liquid crystal polymer form a more stable combination with components such as asphalt and waste rubber powder, effectively reducing the interfacial tension, and reducing the phase separation phenomenon. The modified liquid crystal polymer can better cooperate with rubber powder and carbon fiber, optimize the internal pore structure, while enhancing the high and low temperature performance of asphalt mixture, ensuring the continuity and stability of the permeable channels, thereby improving the comprehensive performance of the waste rubber powder modified emulsified asphalt for permeable pavement.

[0013] Preferably, the mass ratio of poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid), polyethylene glycol and maleic anhydride is 1:0.3:(0.05 - 0.15).

[0014] The modified liquid crystal polymer prepared according to the above mass ratio has good compatibility, can improve the interfacial contact with asphalt, and further enhance the high and low temperature performance and permeable performance of asphalt.

[0015] Preferably, the carbon fiber is modified and prepared by the following steps: Disperse the carbon fiber into the silane coupling agent solution, adjust the pH to acidic, stir and react, then filter, wash and dry to obtain the modified carbon fiber.

[0016] The silane coupling agent undergoes hydrolysis under acidic conditions to generate silanol, which forms covalent bonds with active groups such as hydroxyl groups existing on the surface of the carbon fiber through a condensation reaction, making the silane coupling agent firmly grafted on the surface of the carbon fiber; the groups at the other end of the silane coupling agent can physically entangle or chemically interact with organic components such as asphalt and waste rubber powder, building a molecular bridge between the carbon fiber and the matrix such as asphalt, effectively reducing the interfacial tension between the carbon fiber and asphalt, enhancing the interfacial bonding force between the two, enabling the carbon fiber to be evenly dispersed in the asphalt system, playing its role of enhancing and toughening, and improving the mechanical properties of the asphalt mixture; moreover, the evenly dispersed carbon fiber helps to maintain the stability of the internal permeable pore structure of asphalt, prevent pore blockage, thereby ensuring the good permeable performance of the permeable pavement and extending the service life of the pavement.

[0017] Preferably, the raw materials for preparing the modified carbon fiber further include graphene-loaded layered double hydroxide, which is prepared by the following steps: (1) Disperse magnesium nitrate and aluminum nitrate in a solvent, and stir to obtain a metal salt solution; disperse graphene oxide in a solvent to obtain a graphene oxide dispersion; add the graphene oxide dispersion to the metal salt solution, stir, adjust the pH to alkaline, heat and stir to react. After the reaction is completed, perform a hydrothermal reaction. After cooling, wash the obtained product to neutrality, dry and grind to obtain graphene-loaded layered double hydroxide; (2) Disperse carbon fiber and graphene-loaded layered double hydroxide in a silane coupling agent solution, adjust the pH to acidic after ultrasonic treatment, stir and react, then filter, wash and dry to obtain modified carbon fiber.

[0018] The metal salt solution formed by magnesium nitrate and aluminum nitrate is mixed with the graphene oxide dispersion, heated and stirred under alkaline conditions and subjected to hydrothermal reaction to obtain graphene-loaded layered double hydroxide; graphene-loaded layered double hydroxide has a unique layered structure and ion exchange properties, and graphene oxide has excellent mechanical properties, electrical conductivity and large specific surface area. The composite material formed by the combination of the two has the advantages of both, not only improving the strength and stability of the material, but also providing more active sites for the subsequent combination with carbon fiber; disperse carbon fiber and graphene-loaded layered double hydroxide in a silane coupling agent solution and react under acidic conditions. After the silane coupling agent hydrolyzes, on the one hand, it reacts with the active groups on the surface of the carbon fiber, and on the other hand, it combines with groups such as hydroxyl groups on the surface of the graphene-loaded layered double hydroxide to form chemical bond connections among the three, constructing a stable composite structure; when the modified carbon fiber is dispersed in the asphalt system, the graphene-loaded layered double hydroxide further enhances the interfacial interaction between the carbon fiber and the asphalt, improves the dispersion and stability of the carbon fiber in the asphalt. At the same time, the three act synergistically, helping to form a more stable and uniform pore structure inside the asphalt, improving the water permeability of the permeable pavement and the stability of long-term use, effectively reducing the occurrence of pavement diseases and extending the service life of the pavement.

[0019] Preferably, the emulsifier includes sodium dodecylbenzenesulfonate and polyoxyethylene sorbitan monooleate.

[0020] Sodium dodecylbenzenesulfonate and polyoxyethylene sorbitan monooleate are used as emulsifiers. By reducing the surface tension, asphalt is uniformly dispersed in water to form a stable emulsion system; sodium dodecylbenzenesulfonate is an anionic surfactant, and polyoxyethylene sorbitan monooleate is a non-ionic surfactant. The compounding of the two can produce a synergistic effect, effectively preventing the aggregation and sedimentation of asphalt droplets, ensuring the uniform mixing of each component, and at the same time enhancing the adhesion performance of the emulsion with materials such as aggregates, guaranteeing the construction and use effects of the permeable pavement materials.

[0021] Preferably, the penetration regulator includes ethylene glycol monobutyl ether.

[0022] Ethylene glycol monobutyl ether has good solubility and volatility. In the asphalt system, it can effectively reduce the surface tension of asphalt, improve the compatibility between asphalt and other components, promote the uniform dispersion of waste rubber powder, carbon fiber, etc. in asphalt, and construct a more reasonable pore structure. The polar groups in its molecular structure interact with the polar components in asphalt, and the non-polar part is affinity with organic materials such as waste rubber powder, making the interfacial combination between components closer, reducing pore blockage or uneven distribution caused by incompatibility. The volatility of ethylene glycol monobutyl ether causes it to gradually escape after a period of time, leaving tiny channels inside the asphalt. These channels are interconnected to form an efficient water permeation path, thus significantly improving the water permeability of the waste rubber powder modified emulsified asphalt for permeable pavement, ensuring that the road surface can drain quickly on rainy days, reducing road surface water accumulation, and improving driving safety.

[0023] In a second aspect, the present application provides a method for preparing waste rubber powder modified emulsified asphalt for permeable pavement, adopting the following technical solution: A method for preparing waste rubber powder modified emulsified asphalt for permeable pavement, comprising the following steps: Heat the asphalt to melting and stir to obtain molten asphalt; add the waste rubber powder to the molten asphalt, stir while adding, after continuous stirring, add poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid), stir and then add carbon fiber, and after stirring, obtain a mixture; disperse the emulsifier in the solvent to obtain an emulsifier solution; add the mixture to the emulsifier solution, after shear dispersion, successively add the penetration regulator, stabilizer and anti-aging agent, and after stirring, obtain the waste rubber powder modified emulsified asphalt for permeable pavement.

[0024] The waste rubber powder modified emulsified asphalt for permeable pavement prepared according to the above steps has good interfacial compatibility, can be stored stably, and improves the water permeability and high and low temperature performance of the road surface.

[0025] In summary, the present application includes at least one of the following beneficial technical effects: 1. Waste rubber powder can swell in asphalt, and its flexible chain segments entangle with asphalt molecules, improving the cohesion and flexibility of asphalt; poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) has a rigid rod-like molecular structure, and polar groups such as hydroxyl groups on its molecular chain can form hydrogen bond interactions and π-π stacking interactions with polar components such as aromatics and resins in asphalt, thereby enhancing the intermolecular force with asphalt. At the same time, poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) can form a bridge between rubber powder and asphalt. Its rigid chain segments insert into the cross-linked network of rubber powder and intertwine with the flexible chain segments of rubber powder. The other end is tightly combined with asphalt molecules to form a physical cross-linked network; this network structure effectively restricts the relative movement of rubber powder and asphalt molecules, making the two evenly dispersed, significantly improving the overall compatibility, and reducing the phase separation tendency caused by the differences in component density and polarity; carbon fiber, with its high specific surface area and excellent dispersibility, is evenly distributed in the system, further strengthening the binding force between components and stabilizing the dispersed structure; waste rubber powder and carbon fiber construct a porous network skeleton inside asphalt, and the penetration regulator helps to optimize the internal pore structure, enabling asphalt to form continuous and uniform water-permeable channels; the stabilizer and anti-aging agent act synergistically to ensure the long-term stability of asphalt while maintaining the integrity of the pore structure, ensuring that the permeable pavement always has good water-permeability during long-term use, and realizing the efficient management and utilization of urban rainwater.

[0026] 2. In the pretreatment step, screening and impurity removal can remove impurities in rubber powder to avoid the influence of impurities on the compatibility with asphalt; ball milling treatment can refine the particle size of rubber powder, increase the specific surface area, and make it more easily dispersed in asphalt; mixing and stirring the pretreated rubber powder with tannic acid in a solvent, a large number of phenolic hydroxyl groups contained in tannic acid can react chemically or form hydrogen bond interactions with the surface active groups of rubber powder, improving the surface polarity of rubber powder and making it better combined with polar substances in asphalt; at the same time, tannic acid, as a natural antioxidant, can delay the aging of rubber powder; melting and blending the preliminarily modified rubber powder with polyhydroxyalkanoate, polyhydroxyalkanoate has good biocompatibility and biodegradability, and its molecular chain can entangle with the molecular chain of rubber powder to form a transition layer at the interface, reducing the interfacial tension between the two phases and improving the compatibility of rubber powder and asphalt; extrusion, cooling, pelletizing and aging treatment make the blend system structure more stable, enabling rubber powder to be better dispersed in the modified emulsified asphalt for permeable pavement, reducing phase separation, enhancing the flexibility and elasticity of asphalt, further optimizing the high and low temperature performance and water permeability of the permeable pavement, and extending its service life.

[0027] 3. Poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) is a liquid crystal polymer with strong rigidity. Polyethylene glycol has good flexibility and amphiphilicity, and its long-chain molecules can interpenetrate between the rigid molecular chains of poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid), reducing the overall glass transition temperature of the polymer, enhancing its flexibility and fluidity, and further improving the interfacial contact with asphalt. Maleic anhydride contains active anhydride groups, which can undergo esterification reactions with the hydroxyl groups on the molecular chains of poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) during the melt blending process, and can also react with the hydroxyl groups of polyethylene glycol, forming chemical bond connections among the three to build a bridge structure, enhancing the intermolecular interaction force, making the modified liquid crystal polymer form a more stable combination with components such as asphalt and waste rubber powder, effectively reducing the interfacial tension and reducing the phase separation phenomenon. The modified liquid crystal polymer can better cooperate with rubber powder and carbon fiber to optimize the internal pore structure, while enhancing the high and low temperature performance of asphalt mixtures, ensuring the continuity and stability of the permeable channels, thereby improving the comprehensive performance of waste rubber powder modified emulsified asphalt for permeable pavements. Detailed implementation manners

[0028] The embodiments of the present application disclose a waste rubber powder modified emulsified asphalt for permeable pavements and its preparation method. The raw materials used in the present application can be obtained from commercially available raw materials except as otherwise specified. The following further details the present application with reference to the embodiments: Raw material description: The asphalt is national standard No. 70 petroleum asphalt, purchased from Xingtai Jianlong Asphalt Sales Co., Ltd. The waste rubber powder has a product number of 115 and is purchased from Lingshou Chengyu Mineral Products Processing Factory. Poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) (CAS No.: 70679-92-4) is purchased from Hubei Enxing Biotechnology Co., Ltd. The carbon fiber is short-cut carbon fiber with a specification of 5 mm and is purchased from Yancheng Xiangsheng Carbon Fiber Technology Co., Ltd. Sodium dodecylbenzenesulfonate (CAS No.: 25155-30-0), polyoxyethylene sorbitan monooleate (CAS No.: 9005-65-6), ethylene glycol monobutyl ether (CAS No.: 111-76-2), the stabilizer is polyvinyl alcohol (CAS No.: 9002-89-5), the anti-aging agent is 2,6-di-tert-butyl-4-methylphenol (CAS No.: 128-37-0), tannic acid (CAS No.: 1401-55-4), polyhydroxy fatty acid ester is purchased from Dongguan Zhangmutou Hailan Plastic Processing Factory, polyethylene glycol (CAS No.: 25322-68-3) with a molecular weight of 400 is purchased from Nantong Renda Chemical Co., Ltd., maleic anhydride (CAS No.: 108-31-6), silane coupling agent KH-550 (CAS No.: 919-30-2), and graphene oxide with the number XFSG01 is purchased from Jiangsu Xianfeng Nano Materials Technology Co., Ltd.

[0029] Example 1 Preparation of Solid Waste Rubber Powder Modified Emulsified Asphalt for Permeable Pavement Heat 60 g of asphalt to 160 °C to melt it, and stir at a speed of 400 rpm to obtain molten asphalt; add 15 g of solid waste rubber powder to the molten asphalt, and stir at a speed of 400 rpm while adding, continuously stir for 45 min, add 4 g of poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid), increase the stirring speed to 700 rpm, stir for 30 min, add 1.5 g of carbon fiber, and stir at a speed of 900 rpm for 20 min to obtain a mixture; disperse 3 g of emulsifier in 60 mL of water at 50 °C, and the emulsifier is composed of sodium dodecylbenzenesulfonate and polyoxyethylene sorbitan monooleate with a mass ratio of 1:2 to obtain an emulsifier solution; add the mixture to the emulsifier solution, shear at a shear speed of 8000 rpm for 15 min, sequentially add 0.5 g of ethylene glycol monobutyl ether, 0.3 g of polyvinyl alcohol and 0.2 g of 2,6-di-tert-butyl-4-methylphenol, and stir at a speed of 600 rpm for 20 min to obtain solid waste rubber powder modified emulsified asphalt for permeable pavement.

[0030] Example 2 Preparation of Solid Waste Rubber Powder Modified Emulsified Asphalt for Permeable Pavement Heat 70 g of asphalt to 160 °C to melt it, and stir at a speed of 400 rpm to obtain molten asphalt; add 25 g of solid waste rubber powder to the molten asphalt, and stir at a speed of 400 rpm while adding, continuously stir for 45 min, add 6 g of poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid), increase the stirring speed to 700 rpm, stir for 30 min, add 3.5 g of carbon fiber, and stir at a speed of 900 rpm for 20 min to obtain a mixture; disperse 5 g of emulsifier in 60 mL of water at 50 °C, and the emulsifier is composed of sodium dodecylbenzenesulfonate and polyoxyethylene sorbitan monooleate with a mass ratio of 1:2 to obtain an emulsifier solution; add the mixture to the emulsifier solution, shear at a shear speed of 8000 rpm for 15 min, sequentially add 1.5 g of ethylene glycol monobutyl ether, 0.8 g of polyvinyl alcohol and 0.6 g of 2,6-di-tert-butyl-4-methylphenol, and stir at a speed of 600 rpm for 20 min to obtain solid waste rubber powder modified emulsified asphalt for permeable pavement.

[0031] Example 3 Preparation of Solid Waste Rubber Powder Modified Emulsified Asphalt for Permeable Pavement Heat 65 g of asphalt to 160 °C to melt it, stir at a speed of 400 rpm to obtain molten asphalt; add 20 g of waste rubber powder to the molten asphalt, stir at a speed of 400 rpm while adding, continuously stir for 45 min, add 5 g of poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid), increase the stirring speed to 700 rpm, stir for 30 min, add 2.5 g of carbon fiber, stir at a speed of 900 rpm for 20 min to obtain a mixture; disperse 4 g of emulsifier in 60 mL of water at 50 °C, the emulsifier is composed of sodium dodecylbenzenesulfonate and polyoxyethylene sorbitan monooleate with a mass ratio of 1:2 to obtain an emulsifier solution; add the mixture to the emulsifier solution, shear at a shear speed of 8000 rpm for 15 min, sequentially add 1 g of ethylene glycol monobutyl ether, 0.55 g of polyvinyl alcohol and 0.4 g of 2,6-di-tert-butyl-4-methylphenol, stir at a speed of 600 rpm for 20 min to obtain waste rubber powder modified emulsified asphalt for permeable pavement.

[0032] Example 4 Example 4 is based on Example 3. The difference between Example 4 and Example 3 is only that the waste rubber powder in Example 4 is modified and prepared by the following steps: (1) Pass the waste rubber powder through an 80-mesh sieve to remove impurities, put it into a high-energy ball mill, add grinding balls according to a ball-to-material ratio of 10:1, set the rotation speed at 300 rpm, ball mill for 2 h, and vacuum dry at 80 °C for 2 h to obtain pretreated rubber powder; (2) Mix and disperse 44.65 g of pretreated rubber powder and 0.89 g of tannic acid in 200 mL of 70% ethanol aqueous solution, stir at a speed of 300 rpm for 30 min, filter and vacuum dry at 50 °C for 6 h to obtain preliminarily modified rubber powder; put the preliminarily modified rubber powder prepared above and 4.46 g of polyhydroxyalkanoate into a twin-screw extruder, set the feeding section temperature at 120 °C, the melting section temperature at 170 °C, the extrusion section temperature at 140 °C, the screw rotation speed at 150 rpm, melt and blend for 15 min, extrude and cool and pelletize, and age-treat at 40 °C for 24 h to obtain compatibilized modified rubber powder.

[0033] Example 5 Example 5 is based on Example 3. The difference between Example 5 and Example 3 is only that the waste rubber powder in Example 5 is modified and prepared by the following steps: (1) Pass the waste rubber powder through an 80-mesh sieve to remove impurities, put it into a high-energy ball mill, add grinding balls according to a ball-to-material ratio of 10:1, set the rotation speed at 300 rpm, ball mill for 2 h, and vacuum dry at 80 °C for 2 h to obtain pretreated rubber powder; (2) Mix 40.98 g of pretreated rubber powder and 0.82 g of tannic acid and disperse them in 200 mL of 70% ethanol aqueous solution. Stir at a speed of 300 rpm for 30 min, filter, and then dry in vacuum at 50 °C for 6 h to obtain preliminarily modified rubber powder. Put the preliminarily modified rubber powder prepared above and 8.2 g of polyhydroxyalkanoate into a twin-screw extruder. Set the feeding section temperature at 120 °C, the melting section temperature at 170 °C, the extrusion section temperature at 140 °C, the screw speed at 150 rpm, melt-blend for 15 min, extrude, cool and pelletize, and then conduct aging treatment at 40 °C for 24 h to obtain compatibilized modified rubber powder.

[0034] Example 6 Example 6 is based on Example 3. The difference between Example 6 and Example 3 is only that the solid waste rubber powder in Example 6 is subjected to modification treatment and is prepared by the following steps: (1) Pass the solid waste rubber powder through an 80-mesh sieve to remove impurities, put it into a high-energy ball mill, add grinding balls according to a ball-to-material ratio of 10:1, set the rotation speed at 300 rpm, conduct ball milling treatment for 2 h, and dry in vacuum at 80 °C for 2 h to obtain pretreated rubber powder. (2) Mix 42.74 g of pretreated rubber powder and 0.85 g of tannic acid and disperse them in 200 mL of 70% ethanol aqueous solution. Stir at a speed of 300 rpm for 30 min, filter, and then dry in vacuum at 50 °C for 6 h to obtain preliminarily modified rubber powder. Put the preliminarily modified rubber powder prepared above and 6.41 g of polyhydroxyalkanoate into a twin-screw extruder. Set the feeding section temperature at 120 °C, the melting section temperature at 170 °C, the extrusion section temperature at 140 °C, the screw speed at 150 rpm, melt-blend for 15 min, extrude, cool and pelletize, and then conduct aging treatment at 40 °C for 24 h to obtain compatibilized modified rubber powder.

[0035] Example 7 Example 7 is based on Example 6. The difference between Example 7 and Example 6 is only that the amount of pretreated rubber powder in Example 7 is 46.73 g, the amount of polyhydroxyalkanoate is 2.34 g, and the amount of tannic acid is 0.93 g.

[0036] Example 8 Example 8 is based on Example 6. The difference between Example 8 and Example 6 is only that the amount of pretreated rubber powder in Example 8 is 37.88 g, the amount of polyhydroxyalkanoate is 11.36 g, and the amount of tannic acid is 0.76 g.

[0037] Example 9 Example 9 is based on Example 3. The difference between Example 9 and Example 3 is only that poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) in Example 9 is subjected to modification treatment and is prepared by the following steps: 7.41 g of poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid), 2.22 g of polyethylene glycol and 0.37 g of maleic anhydride were mixed and fed into a twin-screw extruder. The temperature of the feeding section was set at 200 °C, the melting section at 230 °C, the extrusion section at 220 °C, and the screw speed at 150 rpm. The melt blending reaction was carried out for 10 min under nitrogen protection to obtain a blend. After the blend was cooled by water, drawn into strips and pelletized, it was dried in vacuum at 60 °C for 4 h to obtain a modified liquid crystal polymer.

[0038] Example 10 Example 10 was based on Example 3. The difference between Example 10 and Example 3 was only that the poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) in Example 10 was modified and prepared by the following steps: 6.9 g of poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid), 2.07 g of polyethylene glycol and 1.03 g of maleic anhydride were mixed and fed into a twin-screw extruder. The temperature of the feeding section was set at 200 °C, the melting section at 230 °C, the extrusion section at 220 °C, and the screw speed at 150 rpm. The melt blending reaction was carried out for 10 min under nitrogen protection to obtain a blend. After the blend was cooled by water, drawn into strips and pelletized, it was dried in vacuum at 60 °C for 4 h to obtain a modified liquid crystal polymer.

[0039] Example 11 Example 11 was based on Example 3. The difference between Example 11 and Example 3 was only that the poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) in Example 11 was modified and prepared by the following steps: 7.14 g of poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid), 2.14 g of polyethylene glycol and 0.72 g of maleic anhydride were mixed and fed into a twin-screw extruder. The temperature of the feeding section was set at 200 °C, the melting section at 230 °C, the extrusion section at 220 °C, and the screw speed at 150 rpm. The melt blending reaction was carried out for 10 min under nitrogen protection to obtain a blend. After the blend was cooled by water, drawn into strips and pelletized, it was dried in vacuum at 60 °C for 4 h to obtain a modified liquid crystal polymer.

[0040] Example 12 Example 12 was based on Example 11. The difference between Example 12 and Example 11 was only that the amount of poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) in Example 12 was 7.58 g, the amount of polyethylene glycol was 2.27 g, and the amount of maleic anhydride was 0.15 g.

[0041] Example 13 Example 13 is based on Example 11. The only difference between Example 13 and Example 11 is that in Example 13, the dosage of poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) is 6.45 g, the dosage of polyethylene glycol is 1.94 g, and the dosage of maleic anhydride is 1.61 g.

[0042] Example 14 Example 14 is based on Example 3. The only difference between Example 14 and Example 3 is that in Example 14, the carbon fiber is modified and prepared by the following steps: Disperse 5 g of carbon fiber into a 2% (mass concentration) ethanol solution of silane coupling agent KH-550, with a solid-liquid ratio of 1:15. Adjust the pH to 4 using glacial acetic acid, stir and react at a speed of 200 rpm for 4 h, then filter, wash with deionized water, and vacuum dry at 60 °C to obtain modified carbon fiber.

[0043] Example 15 Example 15 is based on Example 14. The only difference between Example 15 and Example 14 is that the raw materials for preparing the modified carbon fiber in Example 15 also include graphene-loaded layered double hydroxides, which are prepared by the following steps: (1) Dissolve 4.24 g of magnesium nitrate and 2.68 g of aluminum nitrate in 150 mL of deionized water, stir at a speed of 200 rpm for 30 min to obtain a metal salt solution; ultrasonically disperse 0.07 g of graphene oxide in 100 mL of deionized water to obtain a graphene dispersion; add the graphene dispersion to the metal salt solution, stir at a speed of 800 rpm for 30 min, and gradually add a mixed alkali solution of 2 mol / L sodium hydroxide and 0.5 mol / L sodium carbonate to adjust the solution pH to 10. Stir and react at 60 °C at a speed of 800 rpm for 4 h. After the reaction, transfer it to a hydrothermal reaction kettle and react at 120 °C for 24 h. After cooling to 30 °C, wash the obtained product alternately with deionized water and absolute ethanol until neutral, and vacuum dry at 60 °C and grind to obtain graphene-loaded layered double hydroxides.

[0044] (2) Mix and disperse 3 g of carbon fiber, the above-prepared graphene-loaded layered double hydroxides, and 0.1 g of silane coupling agent KH-550 into 200 mL of deionized water, ultrasonicate for 30 min, stir and react at 50 °C at a speed of 400 rpm for 2 h, centrifuge and wash with deionized water, and vacuum dry at 80 °C to obtain modified reinforcing filler.

[0045] Comparative Example 1 Comparative Example 1 is based on Example 3. The only difference between Comparative Example 1 and Example 3 is that poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) is not added when preparing the waste rubber powder-modified emulsified asphalt for permeable pavement in Comparative Example 1.

[0046] Preparation of solid waste rubber powder modified emulsified asphalt for permeable pavement Heat 65 g of asphalt to 160 °C to melt it, and stir at a speed of 400 rpm to obtain molten asphalt; add 20 g of solid waste rubber powder to the molten asphalt, while adding and stirring at a speed of 400 rpm, continuously stir for 45 min, add 2.5 g of carbon fiber, and stir at a speed of 900 rpm for 20 min to obtain a mixture; disperse 4 g of emulsifier in 60 mL of water at 50 °C, and the emulsifier is composed of sodium dodecyl benzene sulfonate and polyoxyethylene sorbitan monooleate with a mass ratio of 1:2 to obtain an emulsifier solution; add the mixture to the emulsifier solution, shear at a shear speed of 8000 rpm for 15 min, sequentially add 1 g of ethylene glycol monobutyl ether, 0.55 g of polyvinyl alcohol and 0.4 g of 2,6-di-tert-butyl-4-methylphenol, and stir at a speed of 600 rpm for 20 min to obtain solid waste rubber powder modified emulsified asphalt for permeable pavement.

[0047] Comparative Example 2 Comparative Example 2 is based on Example 3. The difference between Comparative Example 2 and Example 3 is only that carbon fiber is not added when preparing solid waste rubber powder modified emulsified asphalt for permeable pavement in Comparative Example 2.

[0048] Preparation of solid waste rubber powder modified emulsified asphalt for permeable pavement Heat 65 g of asphalt to 160 °C to melt it, and stir at a speed of 400 rpm to obtain molten asphalt; add 20 g of solid waste rubber powder to the molten asphalt, while adding and stirring at a speed of 400 rpm, continuously stir for 45 min, add 5 g of poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid), increase the stirring speed to 700 rpm, and stir for 30 min to obtain a mixture; disperse 4 g of emulsifier in 60 mL of water at 50 °C, and the emulsifier is composed of sodium dodecyl benzene sulfonate and polyoxyethylene sorbitan monooleate with a mass ratio of 1:2 to obtain an emulsifier solution; add the mixture to the emulsifier solution, shear at a shear speed of 8000 rpm for 15 min, sequentially add 1 g of ethylene glycol monobutyl ether, 0.55 g of polyvinyl alcohol and 0.4 g of 2,6-di-tert-butyl-4-methylphenol, and stir at a speed of 600 rpm for 20 min to obtain solid waste rubber powder modified emulsified asphalt for permeable pavement.

[0049] Performance detection test (1) Select "JTG E20-2011 Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" as the standard, test the softening point and ductility of the test specimens, test each specimen three times, and take the average value after measurement. The results are recorded in Table 1.

[0050] (2) Select "SH / T0099.5 - 2005 Determination Method for Storage Stability of Emulsified Asphalt" as the standard, store the sample at 25°C for 5 days, test and calculate the storage stability value D (%), test each sample three times, and take the average value after measurement. The results are recorded in Table 1.

[0051] Table 1 Detection Results of High and Low Temperature Performance and Storage Stability of Solid Waste Rubber Powder Modified Emulsified Asphalt for Permeable Pavement As can be seen from Table 1, the softening point of Examples 1 - 3 is greater than 52.8°C, the ductility is greater than 142.3 cm, and the D value is less than 1.1%. It can be seen that the solid waste rubber powder modified emulsified asphalt prepared in this application has good high and low temperature performance and storage stability, thus improving its water permeability and durability during use.

[0052] As can be seen from Table 1, the difference between Examples 4 - 6 and Example 3 is only that the solid waste rubber powder is modified in Examples 4 - 6. Compared with Example 3, the performance of Examples 4 - 6 has increased significantly. This is because through pretreatment, modification with tannic acid and polyhydroxy fatty acid esters, the specific surface area of the solid waste rubber powder increases, and its dispersibility and interfacial compatibility increase, thus improving the high and low temperature performance and storage stability. In Examples 7 - 8, the optimal ratio of components in the compatibilized modified rubber powder is damaged, and the effect of performance improvement decreases slightly.

[0053] As can be seen from Table 1, the difference between Examples 9 - 13 and Example 3 is only that poly(4 - hydroxybenzoic acid - co - 6 - hydroxy - 2 - naphthoic acid) is modified in Examples 9 - 11. Compared with Example 3, the performance of Examples 9 - 11 has increased. This is because polyethylene glycol and maleic anhydride regulate the performance of the liquid crystal polymer, improve its interfacial compatibility and flexibility, thus enhancing the high and low temperature performance and storage stability of the emulsified asphalt. In Examples 12 - 13, the optimal ratio of components of the modified liquid crystal polymer is damaged, and the synergistic effect between components is affected, resulting in a decrease in performance.

[0054] As can be seen from Table 1, the difference between Example 14 and Example 3 is only that the carbon fiber is modified with a silane coupling agent in Example 14. After enhancing the bonding at the interface with asphalt, its dispersibility and compatibility are improved, and the performance has increased. In Example 15, graphene - loaded layered double hydroxide is also added during the modification of carbon fiber, further enhancing the interfacial interaction between the modified carbon fiber and asphalt, thus improving the high and low temperature performance and storage stability of the emulsified asphalt.

[0055] As can be seen from Table 1, the difference between Comparative Example 1 and Example 3 lies only in that poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid) is not added in Comparative Example 1. Compared with Example 3, the performance of Comparative Example 1 decreases significantly. This is because the compatibility between the rubber powder and the asphalt decreases significantly due to the lack of the regulation of the liquid crystal polymer, and phase separation is likely to occur, resulting in a significant decrease in the high and low temperature performance and storage stability.

[0056] As can be seen from Table 1, the difference between Comparative Example 2 and Example 3 lies only in that carbon fiber is not added in Comparative Example 2. Compared with Example 3, the performance of Comparative Example 2 decreases significantly. This is because the high and low temperature performance decreases and the dispersibility decreases due to the lack of the reinforcement of the carbon fiber, and the storage stability is also affected.

[0057] This specific embodiment is only an explanation of the present application and does not limit the present application. Through the above description, relevant staff can make various changes and modifications without departing from the technical idea of this application. The technical scope of this application is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A solid waste rubber powder modified emulsified asphalt for permeable pavement, characterized in that: Comprising the following components in parts by mass: 60 - 70 parts of asphalt 15 - 25 parts of waste rubber powder 4 - 6 parts of poly(4 - hydroxybenzoic acid - co - 6 - hydroxy - 2 - naphthoic acid) 1.5 - 3.5 parts of carbon fiber 3 - 5 parts of emulsifier 0.5 - 1.5 parts of penetration regulator 0.3 - 0.8 parts of stabilizer 0.2 - 0.6 parts of anti - aging agent.

2. The waste rubber powder modified emulsified asphalt for permeable pavement according to claim 1, characterized in that: The waste rubber powder is subjected to modification treatment and is prepared by the following steps: (1) Pretreat the waste rubber powder, sieve to remove impurities and then ball - mill to obtain pretreated rubber powder; (2) Mix and disperse the pretreated rubber powder and tannic acid in a solvent and stir, filter and dry to obtain preliminarily modified rubber powder; melt - blend the above - prepared preliminarily modified rubber powder and polyhydroxyalkanoate, extrude, cool and pelletize, and carry out aging treatment to obtain compatibilized modified rubber powder.

3. The waste rubber powder modified emulsified asphalt for permeable pavement according to claim 2, wherein: In the step (2), the mass ratio of the pretreated rubber powder, polyhydroxyalkanoate and tannic acid is 1:(0.1 - 0.2):0.

02.

4. The waste rubber powder modified emulsified asphalt for permeable pavement according to claim 1, wherein: The poly(4 - hydroxybenzoic acid - co - 6 - hydroxy - 2 - naphthoic acid) is subjected to modification treatment and is prepared by the following steps: Mix poly(4 - hydroxybenzoic acid - co - 6 - hydroxy - 2 - naphthoic acid), polyethylene glycol and maleic anhydride, carry out melt - blending reaction to obtain a blend, and cool and dry the blend to obtain a modified liquid - crystal polymer.

5. A solid waste rubber powder modified emulsified asphalt for permeable pavement according to claim 4, characterized in that: The mass ratio of poly(4 - hydroxybenzoic acid - co - 6 - hydroxy - 2 - naphthoic acid), polyethylene glycol and maleic anhydride is 1:0.3:(0.05 - 0.15).

6. The waste rubber powder modified emulsified asphalt for permeable pavement according to claim 1, wherein: The carbon fiber is subjected to modification treatment and is prepared by the following steps: Disperse the carbon fiber in a silane coupling agent solution, adjust the pH to acidic, stir and react, then filter, wash and dry to obtain modified carbon fiber.

7. A solid waste rubber powder modified emulsified asphalt for permeable pavement according to claim 6, characterized in that: The preparation raw material of the modified carbon fiber further includes graphene - loaded layered double hydroxide, which is prepared by the following steps: (1) Disperse magnesium nitrate and aluminum nitrate in a solvent, stir to obtain a metal salt solution; disperse graphene oxide in a solvent to obtain a graphene dispersion; add the graphene dispersion to the metal salt solution, stir and then adjust the pH to alkaline, heat and stir to react, after the reaction, carry out hydrothermal reaction, wait for cooling, wash the obtained product to neutrality, dry and grind to obtain graphene - loaded layered double hydroxide; (2) Disperse the carbon fiber and graphene - loaded layered double hydroxide in a silane coupling agent solution, ultrasonicate and then adjust the pH to acidic, stir and react, then filter, wash and dry to obtain modified carbon fiber.

8. A solid waste rubber powder modified emulsified asphalt for permeable pavement according to claim 1, characterized in that: The emulsifier includes sodium dodecylbenzenesulfonate and polyoxyethylene sorbitan monooleate.

9. A solid waste rubber powder modified emulsified asphalt for permeable pavement according to claim 1, characterized in that: The penetration regulator includes ethylene glycol monobutyl ether.

10. A preparation method of solid waste rubber powder modified emulsified asphalt for permeable pavement as described in any one of claims 1-9, characterized in that: Comprising the following steps: Heat the asphalt to melting and stir to obtain molten asphalt; add solid waste rubber powder to the molten asphalt, stir while adding, continue stirring, then add poly(4-hydroxybenzoic acid-co-6-hydroxy-2-naphthoic acid), stir, add carbon fiber, and stir to obtain a mixture; disperse the emulsifier in the solvent to obtain an emulsifier solution; add the mixture to the emulsifier solution, shear and disperse, then sequentially add a penetration regulator, a stabilizer, and an anti-aging agent, and stir to obtain a solid waste rubber powder modified emulsified asphalt for permeable pavement.

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