Hot-mix asphalt regenerant and preparation method thereof

Abstract

The invention relates to the technical field of asphalt regenerant, in particular to a hot-mix asphalt regenerant and a preparation method thereof.The hot-mix asphalt regenerant is prepared from, by weight, 10-20 parts of modified nano silicon dioxide, 60-70 parts of tung oil, 12-18 parts of polyvinyl chloride, 6-9 parts of anti-aging agent and 10-15 parts of penetrating agent, the modified nano silicon dioxide is formed by surface modification of 3-glycidoxypropyltrimethoxysilane and nano silicon dioxide according to the mass ratio of (4-6): 1, the anti-aging agent is 2, 6-di-tert-butyl-4-methylphenol, the penetrating agent is dibutyl phthalate, the dispersing agent is dibutyl phthalate, and the dispersing agent is dibutyl phthalate. According to the hot-mixed asphalt regenerant prepared from the three core components of the tung oil, the modified nano silicon dioxide and the polyvinyl chloride, gaps are filled with the tung oil, the content of light components is increased, the interface bonding force is improved through the modified nano silicon dioxide, and a physical crosslinking reinforcing system of a compact structure and the polyvinyl chloride is formed; the low-temperature crack resistance and the high-temperature permanent deformation resistance of the regenerated asphalt are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of asphalt rejuvenators, and specifically, to a hot mix asphalt rejuvenator and a preparation method thereof. Background Art

[0003] Existing hot mix asphalt rejuvenators can, to a certain extent, improve the performance of asphalt materials. However, under low-temperature conditions, their effects are often not significant enough to completely solve the problem of low-temperature cracking, and there are also certain limitations in terms of high-temperature stability. In view of this, we propose a hot mix asphalt rejuvenator and a preparation method thereof. Summary of the Invention

[0004] The purpose of the present invention is to provide a hot mix asphalt rejuvenator and a preparation method thereof to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides a bionic microporous induced self-healing hydrolysis-resistant elastomeric fender material, which includes the following components: 10 - 20 parts by weight of modified nano-silica, 60 - 70 parts by weight of tung oil, 12 - 18 parts by weight of polyvinyl chloride, 6 - 9 parts by weight of anti-aging agent, and 10 - 15 parts by weight of penetrant. Among them, the modified nano-silica is surface-modified by 3-glycidoxypropyltrimethoxysilane and nano-silica in a mass ratio of 4 - 6:1, the anti-aging agent is 2,6-di-tert-butyl-4-methylphenol, and the penetrant is dibutyl phthalate.

[0006] Preferably, the preparation method of the modified nano-silica is as follows:

[0007] Dissolve 3-glycidoxypropyltrimethoxysilane in a methanol solvent to prepare a certain concentration, then add nano-silica to the solution of 3-glycidoxypropyltrimethoxysilane, stir evenly with a stirrer and heat for reaction. After the reaction is completed, filter, wash with a methanol solvent again, and finally dry in an oven to obtain the modified nano-silica.

[0008] 3-Glycidoxypropyltrimethoxysilane, with the chemical formula C9H20O4Si, is an organosilicon compound and is commonly used as a coupling agent and crosslinking agent in industry. It can react with the hydroxyl groups on the surface of inorganic materials to form strong chemical bonds, thereby improving the bonding performance between organic polymers and inorganic fillers or substrates. The structural feature of 3-glycidoxypropyltrimethoxysilane is that it contains an epoxy group (derived from glycidol), and the epoxy group is a hydrolyzable group. After hydrolysis, a carbonyl group is generated, which undergoes a condensation reaction with the silicon carbonyl group on the surface of nano-SiO2, so that one end of 3-glycidoxypropyltrimethoxysilane is grafted onto nano-SiO 2The modified nano-silica has one end on the surface and the other end connected to the organism, so that the hydrophilicity of the surface rich in carbonyl groups is changed to the lipophilicity of the organic functional groups. It has better lipophilic and hydrophobic properties, better dispersibility and stability, and can be better compatible with asphalt to form a stable dispersion system.

[0009] Preferably, the mass fraction of the 3-glycidyloxypropyltrimethoxysilane in the methanol solvent is 1-5%.

[0010] Preferably, the stirring speed of the stirrer is 300-400 rpm / min, and the stirring time is 10-15 min.

[0011] Preferably, the heating temperature of the mixed solution of nano-silicon dioxide and 3-glycidyloxypropyltrimethoxysilane is 70-75° C., and the reaction time is 4-5 hours.

[0012] Preferably, the modified nano drying temperature is 80-120° C., and the drying time is 1-2 hours.

[0013] In another aspect, the present invention provides a method for preparing a hot mix asphalt regeneration agent, which is used for a hot mix asphalt regeneration agent as described in any one of the above, comprising the following steps:

[0014] Under heating conditions, tung oil and polyvinyl chloride particles are added to the reactor, and stirred with a stirrer at 800-1000r / min until the polyvinyl chloride particles are completely melted and evenly dispersed, and then modified nano-silica is added, and stirring is continued for 10-15 minutes. Finally, an anti-aging agent and a penetrant are added, and the mixture is sheared and dispersed using a high-speed shearing machine until the mixture is completely dissolved and dispersed. The mixture is kept at a certain temperature for a period of time to ensure that all components are fully reacted and fused, and then cooled to room temperature to obtain a hot mix asphalt regeneration agent.

[0015] Tung oil belongs to vegetable oil. Its main components are linoleic acid, eleostearic acid (an unsaturated fatty acid), and fatty acid triglycerides. A large number of ester groups contained in it have good compatibility with asphalt, and it has a high flash point and good heat resistance. It can be used as a natural light oil component to supplement and balance the component loss of aged asphalt. Since tung oil is similar to the oil component in asphalt, tung oil molecules can penetrate into the molecular network of aged asphalt, fill the micropores and cracks generated by aging, supplement the oil component lacking due to aging, adjust the asphalt components, restore the performance of aged asphalt, improve the continuity and compactness of asphalt. The unsaturated fatty acids in tung oil will undergo oxidative polymerization reaction under the action of oxygen in the air to form a dense coating, which helps to restore the elasticity and plasticity of asphalt. However, tung oil will reduce the viscosity of asphalt and to a certain extent reduce the high-temperature performance of aged asphalt, resulting in a decrease in penetration and a reduction in softening point. Therefore, modified nano-silica and polyvinyl chloride are added to improve the high-temperature performance of aged asphalt.

[0016] Due to its unique structural characteristics, especially the huge specific surface area, high porosity, and surface activity, modified nano-silica plays a significant role in improving the physical or chemical properties of aged asphalt. Because modified nano-silica has a large specific surface area, it can absorb the light components in tung oil, slow down the volatilization rate of light components, weaken the softening effect of tung oil, and then increase the elastic properties of recycled asphalt, reduce the J nr value and increase the R value. At the same time, it slows down the performance attenuation degree of recycled asphalt after aging, significantly improves the high-temperature deformation resistance and aging resistance of recycled asphalt. In addition, modified nano-silica can increase the surface free energy of recycled asphalt and the adhesion work of the asphalt-aggregate interface system, reduce the stripping work of the asphalt-aggregate-water system, and significantly improve the water damage resistance of recycled asphalt. Moreover, the particle size of modified nano-silica is small and it is easy to form a uniform dispersion in asphalt, which helps to improve the uniformity and stability of the asphalt microstructure. At the same time, the particles can also fill the voids in the asphalt microstructure, enhance the density of asphalt, reduce the void ratio, and thus improve the impermeability, anti-aging property, and durability of asphalt. Since modified nano-silica has good chemical stability, the addition of modified nano-silica can provide an additional barrier for aged asphalt, improve the resistance of asphalt to chemicals, slow down the oxidation process of asphalt, and extend its service life.

[0017] Polyvinyl chloride is a common synthetic polymer material, which has certain hardness, good tensile properties, is easy to modify and is not easily reacted with other substances. It can effectively improve the hardness of recycled asphalt and will not have a great impact on the stiffness of asphalt. During the recycling process, asphalt undergoes physical or chemical reactions with the molecules in the recycling agent, while polyvinyl chloride does not undergo chemical changes with asphalt and tung oil. It only has a physical cross-linking effect with asphalt, grafting its -CH2- to asphalt, physically modifying the recycled asphalt. Utilizing the strong molecular cohesion of polyvinyl chloride, the structural system of asphalt is strengthened, making the prepared recycled asphalt have better structural strength and mechanical properties.

[0018] The antioxidant 2,6-di-tert-butyl-4-methylphenol. Since free radicals are generated during the aging process of aged asphalt, antioxidants can capture free radicals during the oxidation process, interrupt the free radical chain reaction, protect asphalt from further oxidation attacks, thereby preventing or delaying the degradation of asphalt molecules and maintaining the performance stability of asphalt.

[0019] The penetrant dibutyl phthalate can help tung oil penetrate into the microstructure of hardened asphalt due to its good solubility, soften the hardened asphalt, increase its fluidity and workability, thereby improving the performance of aged asphalt. At the same time, the low volatility and relatively high polarity of dibutyl phthalate enable it to stay in the asphalt mixture well, not easy to evaporate or be extracted by water. In addition, dibutyl phthalate can also be used as a plasticizer to increase the flexibility, plasticity and high-temperature stability of asphalt, reduce low-temperature embrittlement, and thus extend the service life of the recycled asphalt pavement.

[0020] Preferably, the heating temperature of the tung oil and polyvinyl chloride particles is 140 - 160 °C.

[0021] Preferably, the rotation speed of the high-speed shearer is set at 5000 - 10000 rpm, and the shearing time is 20 - 30 min.

[0022] Preferably, the holding temperature of the mixture is 140 - 150 °C, and the heat preservation time is 0.5 - 1 h.

[0023] Compared with the prior art, the beneficial effects of the present invention:

[0024] In this hot mix asphalt rejuvenator and its preparation method, a hot mix asphalt rejuvenator is prepared using three core components: tung oil, modified nano-silica, and polyvinyl chloride. Tung oil provides light components for the aged asphalt, fills the micropores and cracks generated by aging, and reduces the viscosity of the aged asphalt, thereby improving the fluidity of the asphalt. The modified nano-silica obtained by surface modification forms a stronger interfacial bond between the asphalt and tung oil, promoting the uniform dispersion among the components. The large specific surface area reduces the volatilization of tung oil, and the small particle size can penetrate into the microstructure of the asphalt to form a dense network structure. Adding polyvinyl chloride further improves the cohesion and overall stability of the aged asphalt, and thus enhances the low-temperature cracking resistance and high-temperature permanent deformation resistance of the recycled asphalt. Detailed implementation mode

[0025] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] A hot mix asphalt rejuvenator of the present invention comprises the following components: 10 - 20 parts by weight of modified nano-silica, 60 - 70 parts by weight of tung oil, 12 - 18 parts by weight of polyvinyl chloride, 6 - 9 parts by weight of anti-aging agent, and 10 - 15 parts by weight of penetrant. Among them, the modified nano-silica is surface-modified from 3-glycidoxypropyltrimethoxysilane and nano-silica at a mass ratio of 4 - 6:1, the anti-aging agent is 2,6-di-tert-butyl-4-methylphenol, and the penetrant is dibutyl phthalate.

[0027] Example 1

[0028] A hot mix asphalt rejuvenator and its preparation method comprise the following steps:

[0029] S3.1. Prepare the components: 10 parts by weight of modified nano-silica, 65 parts by weight of tung oil, 15 parts by weight of polyvinyl chloride, 8 parts by weight of anti-aging agent 2,6-di-tert-butyl-4-methylphenol, and 12 parts by weight of penetrant dibutyl phthalate. Among them, the modified nano-silica is surface-modified from 3-glycidoxypropyltrimethoxysilane and nano-silica at a mass ratio of 5:1.

[0030] S3.2. Preparation of modified nano-silica: dissolve 3-glycidyloxypropyltrimethoxysilane in methanol solvent to prepare a solution with a mass fraction of 3%, then add nano-silica to the solution of 3-glycidyloxypropyltrimethoxysilane, stir with a stirrer at 400 rpm / min for 15 minutes and heat to react at 75°C for 5 hours. After the reaction is completed, filter and wash with methanol solvent, and finally dry in an oven at 80°C for 2 hours to obtain modified nano-silica.

[0031] S3.3. Prepare a hot mix asphalt regeneration agent: under heating conditions of 160°C, add tung oil and polyvinyl chloride particles into a reactor, stir with an agitator at 800r / min until the polyvinyl chloride particles are completely melted and evenly dispersed, then add modified nano-silica, continue stirring for 15 minutes, finally add an anti-aging agent and a penetrant, use a high-speed shearing machine at 7000rpm to shear and disperse the mixture for 30 minutes, until the mixture is completely dissolved and dispersed, keep the mixture at 150°C for 1 hour to ensure that all components are fully reacted and fused, cool to room temperature, and obtain a hot mix asphalt regeneration agent.

[0032] S3.4. Preparation of regenerated asphalt: Weigh 100g of aged asphalt, heat it to a fluid state and keep it at 140°C, add 10g of hot-mix regeneration agent, and use a high-speed shearing machine to shear at 3000r / min for 10min to obtain regenerated asphalt.

[0033] Example 2

[0034] A hot mix asphalt regeneration agent and a preparation method thereof, comprising the following steps:

[0035] S3.1. Prepare components: 15 parts by weight of modified nano-silica, 65 parts by weight of tung oil, 15 parts by weight of polyvinyl chloride, 8 parts by weight of anti-aging agent 2,6-di-tert-butyl-4-methylphenol and 12 parts by weight of penetrant dibutyl phthalate, wherein the modified nano-silica is surface-modified by 3-glycidyloxypropyltrimethoxysilane and nano-silica in a mass ratio of 5:1.

[0036] S3.2. Preparation of modified nano-silica: dissolve 3-glycidyloxypropyltrimethoxysilane in methanol solvent to prepare a solution with a mass fraction of 3%, then add nano-silica to the solution of 3-glycidyloxypropyltrimethoxysilane, stir with a stirrer at 400 rpm / min for 15 minutes and heat to react at 75°C for 5 hours. After the reaction is completed, filter and wash with methanol solvent, and finally dry in an oven at 80°C for 2 hours to obtain modified nano-silica.

[0037] S3.3. Prepare a hot mix asphalt regeneration agent: under heating conditions of 160°C, add tung oil and polyvinyl chloride particles into a reactor, stir with an agitator at 800r / min until the polyvinyl chloride particles are completely melted and evenly dispersed, then add modified nano-silica, continue stirring for 15 minutes, finally add an anti-aging agent and a penetrant, use a high-speed shearing machine at 7000rpm to shear and disperse the mixture for 30 minutes, until the mixture is completely dissolved and dispersed, keep the mixture at 150°C for 1 hour to ensure that all components are fully reacted and fused, cool to room temperature, and obtain a hot mix asphalt regeneration agent.

[0038] S3.4. Preparation of regenerated asphalt: Weigh 100g of aged asphalt, heat it to a fluid state and keep it at 140°C, add 10g of hot-mix regeneration agent, and use a high-speed shearing machine to shear at 3000r / min for 10min to obtain regenerated asphalt.

[0039] Example 3

[0040] A hot mix asphalt regeneration agent and a preparation method thereof, comprising the following steps:

[0041] S3.1. Prepare components: 20 parts by weight of modified nano-silica, 65 parts by weight of tung oil, 15 parts by weight of polyvinyl chloride, 8 parts by weight of anti-aging agent 2,6-di-tert-butyl-4-methylphenol and 12 parts by weight of penetrant dibutyl phthalate, wherein the modified nano-silica is surface-modified by 3-glycidyloxypropyltrimethoxysilane and nano-silica in a mass ratio of 5:1.

[0042] S3.2. Preparation of modified nano-silica: dissolve 3-glycidyloxypropyltrimethoxysilane in methanol solvent to prepare a solution with a mass fraction of 3%, then add nano-silica to the solution of 3-glycidyloxypropyltrimethoxysilane, stir with a stirrer at 400 rpm / min for 15 minutes and heat to react at 75°C for 5 hours. After the reaction is completed, filter and wash with methanol solvent, and finally dry in an oven at 80°C for 2 hours to obtain modified nano-silica.

[0043] S3.3. Prepare a hot mix asphalt regeneration agent: under heating conditions of 160°C, add tung oil and polyvinyl chloride particles into a reactor, stir with an agitator at 800r / min until the polyvinyl chloride particles are completely melted and evenly dispersed, then add modified nano-silica, continue stirring for 15 minutes, finally add an anti-aging agent and a penetrant, use a high-speed shearing machine at 7000rpm to shear and disperse the mixture for 30 minutes, until the mixture is completely dissolved and dispersed, keep the mixture at 150°C for 1 hour to ensure that all components are fully reacted and fused, cool to room temperature, and obtain a hot mix asphalt regeneration agent.

[0044] S3.4. Preparation of regenerated asphalt: Weigh 100 g of aged asphalt, heat it to a flowing state and keep it at 140 °C, add 10 g of hot mix regenerant, and shear it at 3000 r / min for 10 min using a high-speed shearing machine to obtain regenerated asphalt.

[0045] Comparative Example 1

[0046] Adopt the method of Example 2 without adding modified nano-silica.

[0047] Comparative Example 2

[0048] Adopt the method of Example 2 and use unmodified nano-silica.

[0049] The present invention relates to a hot mix asphalt regenerant prepared by using modified nano-silica. Among them, the performance index test items and test standards of a hot mix asphalt regenerant are as follows:

[0050] According to GB / T 4509-2010 "Determination Method of Asphalt Penetration", this standard stipulates the test method of penetration. Heat the regenerated asphalt and pour it into a small specimen dish with an inner diameter of 55 mm and a depth of 35 mm. Wait for it to cool to room temperature, keep it at a constant temperature of (25 ± 0.1) °C for at least 1.5 h. Place the specimen on the platform of the tester, level it, ensure that the standard needle contacts the surface of the specimen, start timing for 5 seconds, and measure the penetration depth of the needle at a test temperature of (25 ± 0.1) °C and a standard needle of (100 ± 0.05) g. Repeat the test three times, with the distance between each test point being at least 10 mm and at least 10 mm away from the container edge. Take the average value as the final result. Penetration is used to measure the depth of penetration of the standard needle into the asphalt sample at a certain temperature and time, and it is one of the conventional physical property evaluation indexes of asphalt, which characterizes the hardness and softness of asphalt, can reflect the change of asphalt viscosity, and can also be used to represent the hardness and softness of asphalt and the ability to resist shear failure. The larger the penetration, the greater the consistency of asphalt and the harder the asphalt.

[0051] According to GB / T 4508-2010 "Determination Method of Asphalt Ductility", this standard stipulates the test method of ductility. Pour the molten asphalt into a special mold, cool it to room temperature, then place it in a water bath at a test temperature of 10 °C to cool. Take out the mold, use a hot knife to shave off the specimen that is higher than the mold, place the mold back in the water bath. After a period of time, fix both ends of the specimen on the ductility test device, and start stretching the specimen at a speed of 5 cm / min until the specimen breaks. Conduct at least two independent tests on each sample, record the length of the specimen when it breaks, and take the average value as the ductility result. Ductility test is used to measure the length of asphalt when it is stretched to break at a certain temperature, and it is used to characterize the low-temperature ductility of asphalt.

[0052] According to GB_T 4507-2014 "Bitumen softening point - Ring and ball method", this standard stipulates the method for determining the softening point of recycled bitumen. Heat the bitumen to 135 - 150 °C, pour it into a special ring mold for softening point testing, demold it after cooling to room temperature, prepare the steel ball and bracket of the softening point tester to ensure that the steel ball can fall freely. Place the ring mold containing the specimen on the bracket of the tester, place the steel ball on the surface of the bitumen, start heating, raise the temperature at a rate of 5 °C / min, observe when the steel ball falls through the bitumen layer to the metal plate at the bottom. Conduct two independent tests on the same sample, record the temperature at which the steel ball falls, and take the average value of the two test results as the softening point. The softening point test is used to determine the temperature at which the bitumen begins to soften and flow, and can characterize the high - temperature performance of the bitumen.

[0053] Through the above - mentioned standard, a hot - mix asphalt rejuvenator prepared in Examples 1 - 3 and Comparative Examples 1 - 2 was tested, and the obtained data are shown in Table 1:

[0054] Table 1 Performance data of Examples 1 - 3 and Comparative Examples 1 - 2

[0055]

[0056] The above data fully show that compared with Comparative Examples 1 - 2, in Examples 1 - 3, it can be clearly seen the effect of modified nano - silica on the high - temperature and low - temperature performance of a hot - mix asphalt rejuvenator.

[0057] Since the present invention uses modified nano - silica to prepare a hot - mix asphalt rejuvenator, the performance of the recycled bitumen is effectively improved by modified nano - silica, specifically as follows:

[0058] It can be seen from Examples 1 - 3 that:

[0059] With the continuous increase in the content of modified nano-silica, the penetration performance of recycled asphalt decreases significantly. This is because the modified nano-silica adsorbs the light components of tung oil, improves the adhesion between tung oil and asphalt, and enhances the hardness of asphalt, resulting in a decrease in penetration. However, when the penetration of recycled asphalt is too high, its temperature sensitivity increases, which means that its stability at high temperatures weakens and it is prone to softening and deformation. Since tung oil itself has a certain temperature dependence, its physical properties change greatly with temperature, and its brittleness increases at low temperatures, reducing the crack resistance. With the increase in the dosage of nano-silica, the softening point value continuously increases. This is because the physical or chemical reaction between the modified nano-silica and tung oil enhances the stiffness and bonding strength of asphalt, which also means that adding modified nano-silica particles can reduce the temperature sensitivity of recycled asphalt and improve its high-temperature stability. With the increase in the dosage of nano-silica, the ductility of recycled asphalt decreases and its low-temperature performance deteriorates. This is because compared with tung oil recycled asphalt, the addition of modified nano-silica particles with high molecular weight and high specific surface area makes the asphalt less likely to flow and deform. Therefore, the dosage of modified nano-silica cannot be too high. However, when the ductility of recycled asphalt is too high, it will instead reduce the high-temperature stability and elastic recovery ability of recycled asphalt, which means that it is prone to creep and rutting at high temperatures, resulting in the accumulation of permanent deformation of the road surface under cyclic loading and shortening the service life of the road surface. In summary, to enable recycled asphalt to have good high-temperature and low-temperature performance simultaneously, an appropriate amount of modified nano-silica should be added, which can not only ensure that recycled asphalt has good resistance to high-temperature permanent deformation at high temperatures but also has excellent crack resistance at low temperatures.

[0060] According to the above test experiments, a hot mix asphalt rejuvenator prepared according to Example 2 has the optimal performance, so Example 2 is taken as the optimal example.

[0061] It can be seen from the comparison between Example 2 and Comparative Examples 1-2:

[0062] In Comparative Example 1, no modified nano-silica is added, and the effect of the hot mix asphalt rejuvenator on restoring the high-temperature performance of recycled asphalt is worse. Although the small molecules of tung oil supplement the volatile components in the aged asphalt, dissolve the hard components in the aged asphalt, and reduce the viscosity of the aged asphalt, showing a higher penetration, tung oil itself is more sensitive to temperature, which instead makes the high-temperature stability of recycled asphalt worse. Recycled asphalt with a higher ductility can reduce cracking under low-temperature conditions, but it is too soft, prone to deforming the road, reducing the shear strength, and deteriorating the durability. Therefore, without adding modified silica, the adsorption of modified nano-silica is lacking, weakening the softening effect, as well as the surface free energy of recycled asphalt and the adhesion work of the asphalt-aggregate interface system, resulting in poor high-temperature performance.

[0063] In Comparative Example 2, unmodified nano-silica was used, and the high-temperature and low-temperature properties of the recycled asphalt prepared with a hot mix asphalt rejuvenator were poor. This is because unmodified nano-silica has a strong tendency to agglomerate, and it is very difficult to achieve uniform dispersion when added to asphalt, resulting in the formation of local high-concentration regions in the asphalt matrix, which affects the fluidity of asphalt and the stability of the recycled asphalt structure. However, the modified nano-silica improves its dispersibility and compatibility in the asphalt matrix, helps to improve the microstructure of asphalt, enhances its overall performance, and further improves the high-temperature stability of the recycled asphalt. The uniformly dispersed modified nano-silica can form a dense network structure, improving the low-temperature crack resistance and fatigue resistance of the recycled asphalt. Therefore, when using unmodified nano-silica, its high-temperature and low-temperature properties decline.

[0064] In summary, through the three core components of modified nano-silica, tung oil, and polyvinyl chloride, tung oil provides light components for the aged asphalt, the modified nano-silica enhances the interfacial bonding between asphalt and tung oil, and the macromolecular cohesion of polyvinyl chloride conducts physical cross-linking. Under their combined action, the low-temperature crack resistance and high-temperature permanent deformation resistance of the recycled asphalt are improved.

[0065] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification are only preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A hot mix asphalt regeneration agent, characterized in that: The invention comprises the following components: 10-20 parts by weight of modified nano silicon dioxide, 60-70 parts by weight of tung oil, 12-18 parts by weight of polyvinyl chloride, 6-9 parts by weight of an anti-aging agent and 10-15 parts by weight of a penetrant; The modified nano-silica is prepared by surface modification of 3-glycidyloxypropyltrimethoxysilane and nano-silica at a mass ratio of 4 to 6:

1. The anti-aging agent is 2,6-di-tert-butyl-4-methylphenol, and the penetrant is dibutyl phthalate.

2. A hot mix asphalt regeneration agent according to claim 1, characterized in that: The preparation method of the modified nano silicon dioxide is as follows: 3-glycidyloxypropyltrimethoxysilane is dissolved in methanol solvent to prepare a certain concentration, and then nano-silica is added to the solution of 3-glycidyloxypropyltrimethoxysilane, stirred evenly with a stirrer and heated for reaction, filtered after the reaction is completed, washed with methanol solvent, and finally dried in an oven to obtain modified nano-silica.

3. A hot mix asphalt regeneration agent according to claim 2, characterized in that: The mass fraction of the 3-glycidyloxypropyltrimethoxysilane in the methanol solvent is 1-5%.

4. A hot mix asphalt regeneration agent according to claim 2, characterized in that: The stirring speed of the stirrer is 300-400 rpm / min, and the stirring time is 10-15 min.

5. The hot mix asphalt regeneration agent according to claim 2, characterized in that: The heating temperature of the mixed solution of nano-silicon dioxide and 3-glycidyloxypropyltrimethoxysilane is 70-75° C., and the reaction time is 4-5 hours.

6. A hot mix asphalt regeneration agent according to claim 2, characterized in that: The modified nano drying temperature is 80-120° C., and the drying time is 1-2 hours.

7. A method for preparing a hot mix asphalt regeneration agent, used for preparing a hot mix asphalt regeneration agent according to any one of claims 1 to 6, characterized in that: The steps include: Under heating conditions, tung oil and polyvinyl chloride particles are added to the reactor, and stirred with a stirrer at 800-1000r / min until the polyvinyl chloride particles are completely melted and evenly dispersed, and then modified nano-silica is added, and stirring is continued for 10-15 minutes. Finally, an anti-aging agent and a penetrant are added, and the mixture is sheared and dispersed using a high-speed shearing machine until the mixture is completely dissolved and dispersed. The mixture is kept at a certain temperature for a period of time to ensure that all components are fully reacted and fused, and then cooled to room temperature to obtain a hot mix asphalt regeneration agent.

8. The method for preparing a hot mix asphalt regeneration agent according to claim 7, characterized in that: The heating temperature of the tung oil and polyvinyl chloride particles is 140-160°C.

9. The method for preparing a hot mix asphalt regeneration agent according to claim 7, characterized in that: The rotation speed of the high-speed shearing machine is set to 5000-10000 rpm, and the shearing time is 20-30 min.

10. The method for preparing a hot mix asphalt regeneration agent according to claim 7, characterized in that: The mixture is maintained at a temperature of 140-150° C. for 0.5-1 h.

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