High-temperature non-fading colored asphalt mixture and preparation method thereof

Abstract

The invention discloses a high-temperature non-fading colored asphalt mixture and a preparation method thereof, and relates to the technical field of asphalt. According to the invention, the iron oxide pigment is taken as a raw material, under the crosslinking action of a binder, montmorillonite is taken as a coating agent, and the coating modified pigment is formed through coprecipitation, so that the thermal decomposition and oxidation reaction of the pigment are inhibited, and the effects of high temperature resistance and fastness are achieved; then the modified polymer and the modified pigment are subjected to high-speed shearing at a high temperature to prepare a cementing material, and through an intercalation reaction, dispersity is improved, free radicals are quenched, and aging is inhibited; and finally, mixing with aggregate and mineral powder to obtain the colored asphalt mixture. The colored asphalt mixture has the effects of high temperature resistance, fastness and pollution resistance. The modified polymer is prepared from 3, 3 '-dimethoxy-4, 4'-biphenyl diisocyanate, docosyl hydroxypropyl quaternary ammonium salt and erythritol through a copolymerization reaction, a three-dimensional structure is formed, the contact angle between pollutants and the asphalt surface is increased, a closely-arranged molecular layer is formed, and the thermal stability and the fading-resistant effect are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of asphalt, and specifically relates to a high-temperature non-fading colored asphalt mixture and a preparation method thereof. Background Art

[0002] Asphalt pavements have good properties such as sufficient strength, high damping, good adhesion to tires, easy cleaning and maintenance, etc., and are widely used in high-grade highways at home and abroad. With the development of social economy and the progress of science and technology, colored asphalt pavements have attracted the attention of more and more countries in the world. Colored asphalt pavements can not only beautify the environment and improve the road landscape, but also play a role in strengthening traffic warnings and dividing traffic areas.

[0003] Ordinary asphalt pavements are black in themselves, absorb a lot of heat, and will produce the "heat island" effect in cities in hot summer, and cause serious environmental pollution. While colored asphalt pavements are lighter in color, can effectively reduce heat radiation and the urban "heat island" effect, reduce the road surface temperature by 3 - 5°C in the high-temperature season, reduce the volatilization of light components in the colored asphalt binder, are not prone to aging and low-temperature embrittlement, extend the service life of colored asphalt pavements, give full play to the functions of the road within the service life, have less pollution, and meet the requirements for environmental protection. However, due to insufficient resistance to oil pollution (or soil pollution), poor resistance to ultraviolet radiation, and the influence of the use environment, especially the black marks left by the friction between motor vehicle tires and the road surface, colored asphalt pavements are easily polluted, and then quickly lose their color function, and at the same time, the daily maintenance cost is relatively high. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-temperature non-fading colored asphalt mixture and a preparation method thereof to solve the problems existing in the prior art.

[0005] To solve the above technical problems, the present invention provides the following technical solution: A high-temperature non-fading colored asphalt mixture, by weight, mainly includes 85 - 111 parts of binder, 42 - 46 parts of coarse aggregate, 34 - 40 parts of fine aggregate, and 37 - 41 parts of mineral powder.

[0006] Further, the binder is prepared by high-speed shear mixing of base oil, terpene resin, modified polymer, decolorizing agent, and modified pigment.

[0007] Further, the modified polymer is copolymerized from 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, dodecyl hydroxypropyl quaternary ammonium salt, and erythritol.

[0008] Further, the modified pigment is prepared by coating the surface of iron oxide-based pigment with montmorillonite as a coating agent through the cross-linking action of a binder.

[0009] Further, a preparation method of a high-temperature non-fading colored asphalt mixture includes the following preparation steps:

[0010] (1) Mix 22 - 46 parts of 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 13 - 25 parts of dodecyl hydroxypropyl quaternary ammonium salt, 10 - 24 parts of erythritol, and 0.5 - 2.5 parts of chain extender evenly. Keep at 85°C for 25 - 35 min under a vacuum of -0.05 to -0.03 MPa, cool down to 70 - 80°C, add 0.03 - 0.07 parts of dibutyltin dilaurate, react under stirring at 110 rpm for 3 - 5 h, and let stand for 25 - 35 min under a vacuum of -0.06 to -0.08 MPa to obtain a modified polymer.

[0011] (2) Disperse 11 - 17 parts of montmorillonite, 18 - 26 parts of binder, and 30 - 50 parts of ethanol at 60 - 70°C and 200 rpm for 40 - 60 min, add 4 - 8 parts of iron oxide-based pigment, continue to disperse for 5 - 10 min, filter with a filter screen with a pore size of 0.2 - 0.6 μm, collect the solid, and dry at 40°C for 10 - 20 h to obtain a modified pigment.

[0012] (3) Place 50 - 60 parts of matrix asphalt, 32 - 48 parts of terpene resin with a molecular weight of 850 - 1250, 6 - 14 parts of modified polymer, 4 - 6 parts of decolorizing agent, and 8 - 18 parts of modified pigment in a high-speed shearer, and perform high-speed shearing at 120 - 150°C and 5000 - 7000 rpm for 20 - 30 min to obtain a binder.

[0013] (4) Mix 85 - 111 parts of binder, 42 - 46 parts of coarse aggregate, 34 - 40 parts of fine aggregate, and 37 - 41 parts of mineral powder evenly to obtain a high-temperature non-fading colored asphalt mixture.

[0014] Further, the chain extender in step (1) is any one of trimethylolpropane, neopentyl glycol, and N,N-dihydroxy(diisopropyl)aniline.

[0015] Further, the binder in step (2) is isopropyl dodecylbenzenesulfonyl titanate.

[0016] Further, the particle size of the montmorillonite in step (2) is 40 - 80 nm, and the particle size of the iron oxide-based pigment is 1 - 2 μm; the iron oxide-based pigment is any one of iron oxide red, iron oxide yellow, iron oxide blue, and iron oxide green.

[0017] Further, the parameters of the matrix asphalt in step (3) are: penetration at 25°C is 60 - 100 mm, softening point is 46 - 54°C, and ductility at 15°C is greater than 100 cm.

[0018] Further, the coarse aggregate described in step (4) is gravel with a size of 5 - 15 mm, the fine aggregate is limestone with a size of 2.15 - 5.45 mm, and the particle size of the mineral powder is 0.05 - 0.25 mm.

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0020] The present invention uses iron oxide - based pigments as raw materials. Under the cross - linking action of a binder, with montmorillonite as a coating agent, a coated and modified pigment is formed through coprecipitation. During the heating process, a certain barrier effect can be achieved between the layers, absorbing part of the heat, restricting the migration and diffusion of internal metal ions, thereby inhibiting the thermal decomposition and oxidation reaction of the pigment, and further achieving the effects of high temperature resistance and non - fading. At the same time, the metal ions contained in montmorillonite can absorb and consume oxidation substances such as free radicals through the change of their own oxidation states, further enhancing the anti - fading performance. Then, the modified polymer and the modified pigment are sheared at high speed at high temperature to obtain a binder. During the shearing process, the cations in the modified polymer can carry out an intercalation reaction with the montmorillonite on the surface of the modified pigment, expanding the layer spacing, improving the dispersibility, and further facilitating better contact with free radicals in the asphalt, generating a quenching effect and forming macromolecular free radicals, thereby reducing the attack of free radicals on the asphalt mixture and effectively inhibiting the occurrence of aging. Finally, it is mixed with aggregates and mineral powder to obtain a colored asphalt mixture to achieve the effects of high temperature resistance, non - fading, and anti - pollution.

[0021] The modified polymer is prepared by copolymerization of 3,3’ - dimethoxy - 4,4’ - biphenyl diisocyanate, dodecyl hydroxypropyl quaternary ammonium salt, and erythritol, forming a three - dimensional structure, significantly improving the thermal stability and anti - fading effect. At the same time, it increases the contact angle between pollutants and the asphalt surface, making it difficult for pollutants to spread and adhere to the asphalt surface, thereby achieving the anti - pollution effect. The methoxy groups contained in 3,3’ - dimethoxy - 4,4’ - biphenyl diisocyanate can combine with free radicals to form relatively stable products, interrupting the free - radical chain reaction process, and further reducing the phenomenon of pigment fading caused by oxidation, achieving the anti - fading performance. The long - chain alkyl groups introduced by dodecyl hydroxypropyl quaternary ammonium salt have a low surface energy and can form a closely arranged molecular layer on the asphalt surface, reducing the adhesion of polluting liquids to the asphalt surface, thereby achieving the anti - pollution performance. Detailed implementation manners

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0023] The method provided by the present invention is described in detail through the following embodiments. The test methods for each index of the high-temperature non-fading colored asphalt mixture prepared in the following embodiments are as follows:

[0024] Marshall stability: Take the same mass of the embodiment and the comparative example, test according to T0709, and test again after soaking in diesel at 25°C for 24 hours.

[0025] Mass loss after oil immersion: Take the same mass of the embodiment and the comparative example, take it out and drain it after soaking in diesel at 25°C for 48 hours, weigh the mass after soaking, and calculate the mass loss.

[0026] 60°C rutting dynamic stability: Take the same mass of the embodiment and the comparative example, and test according to T0719.

[0027] UV aging performance: Take the same mass of the embodiment and the comparative example, irradiate with a UV lamp with a wavelength of 300 - 360 nm at an ambient temperature of 60°C for 100 hours, observe the fading of the sample, where the sample is 10 cm away from the UV light source.

[0028] Example 1

[0029] (1) Mix 22 parts of 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 13 parts of dodecyl hydroxypropyl quaternary ammonium salt, 10 parts of erythritol, and 0.5 part of trimethylolpropane evenly, keep at -0.05 MPa and 85°C for 25 minutes, cool down to 70°C, add 0.03 part of dibutyltin dilaurate, react under stirring at 110 rpm for 3 hours, and let it stand for 25 minutes under a vacuum of -0.06 MPa to obtain a modified polymer;

[0030] (2) Disperse 11 parts of montmorillonite with a particle size of 40 nm, 18 parts of isopropyl tridodecylbenzenesulfonyl titanate, and 30 parts of ethanol at 60°C and 200 rpm for 40 minutes, add 4 parts of iron oxide red with a particle size of 1 μm, continue to disperse for 5 minutes, filter with a filter screen with a pore size of 0.2 μm, collect the solid, and dry at 40°C for 10 hours to obtain a modified pigment;

[0031] (3) Put 50 parts of base asphalt with a penetration of 60 mm at 25°C, a softening point of 46°C, and an elongation greater than 100 cm at 15°C, 32 parts of terpene resin with a molecular weight of 850, 6 parts of modified polymer, 4 parts of decolorizer, and 8 parts of modified pigment into a high-speed shearer, and shear at 120°C and 5000 rpm for 20 minutes to obtain a binder;

[0032] (4) Mix 85 parts of binder, 42 parts of 5-mm crushed stone, 34 parts of 2.15-mm limestone, and 37 parts of mineral powder with a particle size of 0.05 mm evenly to obtain a high-temperature non-fading colored asphalt mixture.

[0033] Example 2

[0034] (1) Mix 34 parts of 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 19 parts of dodecyl hydroxypropyl trimonium salt, 17 parts of erythritol, and 1.5 parts of neopentyl glycol evenly, maintain at -0.04 MPa vacuum and 85 °C for 30 min, cool down to 75 °C, add 0.05 part of dibutyltin dilaurate, react under stirring at 110 rpm for 4 h, and let stand for 30 min under -0.07 MPa vacuum to obtain a modified polymer;

[0035] (2) Disperse 14 parts of montmorillonite with a particle size of 60 nm, 22 parts of isopropyl tridodecylbenzenesulfonyl titanate, and 40 parts of ethanol at 65 °C and 200 rpm for 50 min, add 6 parts of iron oxide yellow with a particle size of 1.5 μm, continue to disperse for 7.5 min, filter with a filter screen with a pore size of 0.4 μm, collect the solid, and dry at 40 °C for 15 h to obtain a modified pigment;

[0036] (3) Place 55 parts of matrix asphalt with a penetration of 80 mm at 25 °C, a softening point of 50 °C, and an elongation greater than 100 cm at 15 °C, 40 parts of terpene resin with a molecular weight of 1050, 10 parts of modified polymer, 5 parts of decolorizer, and 13 parts of modified pigment in a high-speed shearer, and perform high-speed shearing at 135 °C and 6000 rpm for 25 min to obtain a binder;

[0037] (4) Mix 98 parts of binder, 44 parts of 10 mm gravel, 37 parts of 3.8 mm limestone, and 39 parts of mineral powder with a particle size of 0.15 mm evenly to obtain a high-temperature non-fading colored asphalt mixture.

[0038] Example 3

[0039] (1) Mix 46 parts of 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 25 parts of dodecyl hydroxypropyl trimonium salt, 24 parts of erythritol, and 2.5 parts of N,N-dihydroxy(diisopropyl)aniline evenly, maintain at -0.03 MPa vacuum and 85 °C for 35 min, cool down to 80 °C, add 0.07 part of dibutyltin dilaurate, react under stirring at 110 rpm for 5 h, and let stand for 35 min under -0.08 MPa vacuum to obtain a modified polymer;

[0040] (2) Disperse 17 parts of montmorillonite with a particle size of 80 nm, 26 parts of isopropyl tridodecylbenzenesulfonyl titanate, and 50 parts of ethanol at 70 °C and 200 rpm for 60 min, add 8 parts of iron oxide blue with a particle size of 2 μm, continue to disperse for 10 min, filter with a filter screen with a pore size of 0.6 μm, collect the solid, and dry at 40 °C for 20 h to obtain a modified pigment;

[0041] (3) Put 60 parts of base asphalt with a penetration of 100 mm at 25°C, a softening point of 54°C, and an elongation at 15°C greater than 100 cm, 48 parts of terpene resin with a molecular weight of 1250, 14 parts of modified polymer, 6 parts of decolorizing agent, and 18 parts of modified pigment into a high-speed shearer, and perform high-speed shearing at 150°C and 7000 rpm for 30 min to obtain a binder.

[0042] (4) Mix 111 parts of binder, 46 parts of 15-mm crushed stone, 40 parts of 5.45-mm limestone, and 41 parts of mineral powder with a particle size of 0.25 mm evenly to obtain a high-temperature non-fading colored asphalt mixture.

[0043] Comparative Example 1

[0044] The difference between Comparative Example 1 and Example 2 is that step (2) is absent, and step (3) is changed to: Put 55 parts of base asphalt with a penetration of 80 mm at 25°C, a softening point of 50°C, and an elongation at 15°C greater than 100 cm, 40 parts of terpene resin with a molecular weight of 1050, 10 parts of modified polymer, 5 parts of decolorizing agent, and 13 parts of iron oxide yellow with a particle size of 1.5 μm into a high-speed shearer, and perform high-speed shearing at 135°C and 6000 rpm for 25 min to obtain a binder. The remaining steps are the same as those in Example 2.

[0045] Comparative Example 2

[0046] The difference between Comparative Example 2 and Example 2 lies in step (3). Step (3) is changed to: Put 55 parts of base asphalt with a penetration of 80 mm at 25°C, a softening point of 50°C, and an elongation at 15°C greater than 100 cm, 40 parts of terpene resin with a molecular weight of 1050, 10 parts of modified polymer, 5 parts of decolorizing agent, and 13 parts of modified pigment into a stirrer, and stir at 135°C and 200 rpm for 25 min to obtain a binder. The remaining steps are the same as those in Example 2.

[0047] Comparative Example 3

[0048] The difference between Comparative Example 3 and Example 2 is that 3,3'-dimethoxy-4,4'-biphenyl diisocyanate is not added when preparing the modified polymer. The remaining steps are the same as those in Example 2.

[0049] Comparative Example 4

[0050] The difference between Comparative Example 4 and Example 2 is that dodecyl hydroxypropyl quaternary ammonium salt is not added when preparing the modified polymer. The remaining steps are the same as those in Example 2.

[0051] Comparative Example 5

[0052] The difference between Comparative Example 5 and Example 2 is that erythritol is not added when preparing the modified polymer. The remaining steps are the same as those in Example 2.

[0053] Effect Example

[0054] The performance analysis results of the high-temperature non-fading colored asphalt mixtures using Examples 1 to 3 and Comparative Examples 1 to 5 of the present invention are given in Table 1 below.

[0055] Table 1

[0056]

[0057] From the comparison of the experimental data of Examples 1, 2, 3 and Comparative Example 1, it can be found that under the cross-linking action of the binder, using montmorillonite as the coating agent, the coated and modified pigment formed by coprecipitation can play a heat insulation role, absorb heat, limit the migration and diffusion of internal metal ions, inhibit the thermal decomposition and oxidation reaction of the pigment, and achieve the effects of high temperature resistance and non-fading. At the same time, the metal ions contained in montmorillonite absorb and consume oxidation substances such as free radicals through the change of their own oxidation states, strengthening the anti-fading performance; from the comparison of the experimental data of Examples 1, 2, 3 and Comparative Example 2, it can be found that the binder is prepared by high-speed shearing of the modified polymer and the modified pigment at high temperature. During the shearing process, the cations in the modified polymer can carry out an intercalation reaction with the montmorillonite on the surface of the modified pigment, expanding the layer spacing, improving the dispersibility, and then contributing to better contact with the free radicals in the asphalt, generating a quenching effect and forming macromolecular free radicals, thereby reducing the attack of free radicals on the asphalt mixture and effectively inhibiting the occurrence of aging; from the comparison of the experimental data of Examples 1, 2, 3 and Comparative Examples 3, 4, 5, it can be found that the modified polymer prepared by copolymerization of 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, dodecyl hydroxypropyl quaternary ammonium salt and erythritol has a three-dimensional structure, significantly improving the thermal stability and anti-fading effect, and increasing the contact angle between the pollutant and the asphalt surface, making it difficult for the pollutant to spread and adhere to the asphalt surface, achieving the effect of pollution resistance.

[0058] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

Claims

1. A high temperature non-fading colored asphalt mixture, characterized in that: In terms of weight, it mainly includes 85 to 111 parts of binder, 42 to 46 parts of coarse aggregate, 34 to 40 parts of fine aggregate and 37 to 41 parts of mineral powder.

2. A high temperature non-fading colored asphalt mixture according to claim 1, characterized in that: The binder is prepared by mixing base oil, terpene resin, modified polymer, decolorizing agent and modified pigment through high-speed shearing.

3. A high temperature non-fading colored asphalt mixture according to claim 2, characterized in that: The modified polymer is prepared by copolymerizing 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, behenyl hydroxypropyl quaternary ammonium salt and erythritol.

4. The high temperature non-fading colored asphalt mixture according to claim 2, characterized in that: The modified pigment is prepared by using montmorillonite as a coating agent and coating the surface of an iron oxide pigment through a cross-linking action of a binder.

5. A method for preparing a high temperature non-fading colored asphalt mixture, characterized in that: The method comprises the following preparation steps: (1) 22 to 46 parts of 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 13 to 25 parts of docosylhydroxypropyl quaternary ammonium salt, 10 to 24 parts of erythritol, and 0.5 to 2.5 parts of a chain extender are mixed uniformly, maintained at 85° C. for 25 to 35 minutes under a vacuum degree of -0.05 to -0.03 MPa, cooled to 70 to 80° C., 0.03 to 0.07 parts of dibutyltin dilaurate are added, reacted for 3 to 5 hours under stirring at 110 rpm, and allowed to stand for 25 to 35 minutes under a vacuum degree of -0.06 to -0.08 MPa to obtain a modified polymer; (2) 11 to 17 parts of montmorillonite, 18 to 26 parts of a binder, and 30 to 50 parts of ethanol are dispersed at 60 to 70° C. and 200 rpm for 40 to 60 minutes, 4 to 8 parts of an iron oxide pigment are added, and the dispersion is continued for 5 to 10 minutes. The mixture is filtered through a filter with a pore size of 0.2 to 0.6 μm, the solid is collected, and the mixture is dried at 40° C. for 10 to 20 hours to obtain a modified pigment; (3) placing 50-60 parts of base asphalt, 32-48 parts of terpene resin with a molecular weight of 850-1250, 6-14 parts of modified polymer, 4-6 parts of decolorizing agent, and 8-18 parts of modified pigment in a high-speed shearing machine, and high-speed shearing at 120-150° C. and 5000-7000 rpm for 20-30 minutes to obtain a binder; (4) 85 to 111 parts of binder, 42 to 46 parts of coarse aggregate, 34 to 40 parts of fine aggregate, and 37 to 41 parts of mineral powder are mixed evenly to prepare a high-temperature non-fading colored asphalt mixture.

6. The method for preparing a high temperature non-fading colored asphalt mixture according to claim 5, characterized in that: The chain extender in step (1) is any one of trimethylolpropane, neopentyl glycol, and N,N-dihydroxy(diisopropyl)aniline.

7. The method for preparing a high temperature non-fading colored asphalt mixture according to claim 5, characterized in that: The adhesive in step (2) is isopropyl tridecylbenzenesulfonyl titanate.

8. The method for preparing a high temperature non-fading colored asphalt mixture according to claim 5, characterized in that: In step (2), the particle size of the montmorillonite is 40-80 nm, and the particle size of the iron oxide pigment is 1-2 μm; the iron oxide pigment is any one of iron oxide red, iron oxide yellow, iron oxide blue, and iron oxide green.

9. The method for preparing a high temperature non-fading colored asphalt mixture according to claim 5, characterized in that: The parameters of the matrix asphalt in step (3) are: needle penetration at 25°C of 60 to 100 mm, softening point of 46 to 54°C, and elongation at 15°C of more than 100 cm.

10. The method for preparing a high temperature non-fading colored asphalt mixture according to claim 5, characterized in that: In step (4), the coarse aggregate is crushed stone with a diameter of 5 to 15 mm, the fine aggregate is limestone with a diameter of 2.15 to 5.45 mm, and the particle size of the mineral powder is 0.05 to 0.25 mm.

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