High and low temperature resistant coal-pitch-containing asphalt mixture and preparation method thereof

Abstract

The invention discloses a high and low temperature resistant coal-pitch-containing asphalt mixture and a preparation method thereof, and relates to the field of asphalt mixtures, the high and low temperature resistant coal-pitch-containing asphalt mixture comprises the following raw materials by weight: 20-25 parts of modified coal pitch, 40-45 parts of gravel, 10-15 parts of an auxiliary agent, and 8-10 parts of mineral powder. The modified coal pitch is obtained by modifying coal pitch through modified SBS (styrene butadiene styrene), and the modified SBS is obtained by grafting SBS and a reaction product of 5-amino-2-hydroxycycloheptyl-2, 4, 6-triene-1-ketone, 3-hydroxy-5-nitrothiophene-2-carboxylic acid methyl ester, 4-acetyl-3-nitrobenzoic acid methyl ester and the like. The auxiliary agent is an epoxy group-containing expanded graphite-glass fiber grafted product obtained by reaction of expanded graphite, glass fiber and the like. And the modified coal pitch and the auxiliary agent are combined for use, so that the interface bonding force between the modified coal pitch and the glass fibers and the expanded graphite is enhanced, and the asphalt mixture is endowed with relatively strong high and low temperature resistance, flame retardance, smoke suppression and aging resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of asphalt mixture, in particular to a high and low temperature resistant coal-containing asphalt mixture and a preparation method thereof. BACKGROUND

[0002] As the core material in the field of road engineering and construction, asphalt mixture is widely used in road construction, municipal engineering, airport runway and special engineering scenarios due to its excellent mechanical properties, construction flexibility and durability. The asphalt mixture usually includes asphalt binder, aggregate and additives (such as fiber, regenerant, flame retardant) and other components.

[0003] The addition of glass fiber in the coal-containing asphalt mixture can effectively inhibit the shear deformation of the asphalt mixture at high temperature, and improve the high temperature resistance of the asphalt mixture. The physical adsorption can increase the interfacial bonding strength between the asphalt and the glass fiber, and the bridging effect of the glass fiber can prevent the expansion of low temperature cracks, thereby improving the low temperature resistance of the asphalt mixture. However, the interface bonding strength between the glass fiber and the coal asphalt is only through physical adsorption, and the interface bonding strength needs to be improved. The rigidity of the glass fiber leads to low temperature brittleness, which is not conducive to the maintenance of low temperature resistance.

[0004] In addition, the asphalt has strong flammability, which reduces the use safety of the asphalt mixture. Ultraviolet radiation and oxidation can both accelerate the aging of the asphalt mixture, shorten its service life and reduce its durability.

[0005] In summary, it is urgent to find a suitable modification method to enhance the interfacial bonding strength between the asphalt and the glass fiber, further improve the high and low temperature resistance of the asphalt mixture, and improve the flame retardancy, ultraviolet resistance and oxidation resistance of the asphalt mixture, so as to obtain an asphalt mixture with excellent comprehensive performance. SUMMARY

[0006] In order to solve the above technical problems, the present application provides a high and low temperature resistant coal-containing asphalt mixture and a preparation method thereof.

[0007] The object of the present application can be achieved by the following technical solutions:

[0008] A high and low temperature resistant coal-containing asphalt mixture, comprising the following raw materials by weight: modified coal asphalt 20-25 parts, crushed stone 40-45 parts, additives 10-15 parts, and mineral powder 8-10 parts.

[0009] Further, the crushed stone is granite with a particle size range of 5-10mm, which is obtained by crushing with a roller crusher; the mineral powder is mineral particles with a particle size of 0.5-0.8mm, which is obtained by crushing with a jaw crusher.

[0010] The high and low temperature resistant coal-tar pitch-containing asphalt mixture is prepared by the following steps:

[0011] The mixture is prepared by stirring the crushed stone and half of the mineral powder at 175-185 DEG C for 8-10 s; the temperature of the mixture is adjusted to 170-180 DEG C, the modified coal-tar pitch is sprayed into the mixture in two equal portions under stirring, the stirring is continued for 15-20 s, the temperature is adjusted to 160-170 DEG C, the additives and the other half of the mineral powder are added, the stirring is continued for 4-6 min, and the mixture is discharged to obtain the asphalt mixture;

[0012] Further, the interval between the two times of adding the modified coal-tar pitch is 6-10 s, and the spraying rate of the modified coal-tar pitch is 0.6-0.8 kg / s;

[0013] The modified coal-tar pitch is prepared by the following steps:

[0014] Step E1, in a protective gas atmosphere, methyl carboxylate is stirred and heated in tetrahydrofuran, and amino-containing cycloheptatriene and zinc chloride are added to obtain product c1; product c1, DMF and ethanol are mixed, and a reducing agent and a catalyst are added to obtain product c2;

[0015] Step E2, methyl benzoate, DMAC and methanol are mixed in a protective gas atmosphere, and product c2 and ammonium sulfate are added after heating to obtain product c3; product c3, DMF and isopropyl alcohol are mixed, and tin dichloride and dilute hydrochloric acid are added to obtain product c4 after heating and stirring;

[0016] Step E3, product c4 is added to anhydrous tetrahydrofuran and anhydrous methanol in a protective gas atmosphere, and after stirring, methylene triphenyl phosphine is added to obtain product c5 after heating and refluxing; product c5, SBS and solvent a are mixed in a protective gas atmosphere, and an initiator is added to obtain modified SBS after heating and stirring;

[0017] Step E4, coal-tar pitch and toluene are mixed and stirred at room temperature to obtain pretreated coal-tar pitch; in a protective gas atmosphere, the pretreated coal-tar pitch is heated and stirred, and then modified SBS is added after further heating; after further heating, boron trifluoride is added to obtain modified coal-tar pitch after further stirring;

[0018] The modified coal-tar pitch is prepared by the following steps:

[0019] Step E1, in a protective gas atmosphere, methyl carboxylate is stirred and heated in tetrahydrofuran to 80-90 DEG C, and amino-containing cycloheptatriene and zinc chloride are added to obtain product c1 after constant temperature stirring for 8-8.5 h; product c1, DMF and ethanol are mixed, and a reducing agent and a catalyst are added to obtain product c2 after stirring at room temperature for 25-35 min;

[0020] Further, the amount ratio of methyl carboxylate, tetrahydrofuran, amino-containing cycloheptatriene, zinc chloride is 22-24 g: 85-95 mL: 15-17 g: 0.4-0.6 g; the methyl carboxylate is 3-hydroxy-5-nitrothiophene-2-carboxylic acid methyl ester; the amino-containing cycloheptatriene is 5-amino-2-hydroxycyclohepta-2,4,6-triene-1-ketone; the amount ratio of product c1, DMF, ethanol, reducing agent, catalyst is 40-42 g: 60-70 mL: 50-60 mL: 13-15 g: 0.3-0.5 g; the reducing agent is tetrahydroxydiborane; and the catalyst is 4,4'-dipyridyl;

[0021] In the reaction process of step E1, the ester group of the methyl carboxylate reacts with the ester group of the amino-containing cycloheptatriene to obtain product c1; and the nitro group in product c1 is catalytically reduced to an amino group to obtain product c2;

[0022] Step E2, methyl benzoate, DMAC, methanol are mixed and stirred in a protective gas atmosphere for 20-30 min, heated to 80-85°C, product c2 and ammonium sulfate are added, constant temperature stirring reaction for 6.5-7.5 h to obtain product c3; product c3, DMF, isopropyl alcohol are mixed and stirred for 30-40 min, tin dichloride and dilute hydrochloric acid are added, and stirring reaction is carried out at 50-60°C for 4-4.5 h to obtain product c4;

[0023] Further, the amount ratio of methyl benzoate, DMAC, methanol, product c2, ammonium sulfate is 24-26 g: 50-60 mL: 55-65 mL: 38-40 g: 0.27-0.31 g; the methyl benzoate is 4-acetyl-3-nitrobenzoic acid methyl ester; the amount ratio of product c3, DMF, isopropyl alcohol, tin dichloride, dilute hydrochloric acid is 55-57 g: 90-100 mL: 50-60 mL: 20-22 g: 20-30 mL; the mass fraction of dilute hydrochloric acid is 8-10%;

[0024] In the reaction process of step E2, the ester group of the methyl benzoate reacts with the amino group of product c2 to obtain product c3; and the nitro group of product c3 is selectively reduced to an amino group to obtain product c4;

[0025] Step E3, product c4 is added into anhydrous tetrahydrofuran and anhydrous methanol in a protective gas atmosphere, stirred for 40-45 min, then methylene triphenyl phosphine is added, and reflux stirring reaction is carried out at 50-55°C for 6-7 h to obtain product c5; product c5, SBS and solvent a are mixed and stirred in a protective gas atmosphere for 1-1.5 h, an initiator is added, heated to 60-70°C, and stirring reaction is carried out for 7.5-8 h to obtain modified SBS;

[0026] Further, the ratio of the amount of product c4, anhydrous tetrahydrofuran, anhydrous methanol, methylene triphenyl phosphine is 53-55 g: 100-110 mL: 60-70 mL: 29-31 g; the ratio of the amount of product c5, SBS, solvent a, initiator is 50-52 g: 155-165 g: 450-550 mL: 1-1.5 g; solvent a is a mixture of toluene and cyclohexane in a volume ratio of 2-2.5: 1.5; the initiator is a mixture of dibenzoyl peroxide and azobisisobutyronitrile in a mass ratio of 1: 1.5-2;

[0027] In the reaction process of step E3, the terminal carbonyl group of product c4 reacts with methylene triphenyl phosphine to obtain product c5 containing a terminal carbon-carbon double bond, an amino group, a hydroxyl-containing thiophene, a hydroxyl-containing cycloheptatriene, etc.; product c5 is grafted with SBS to obtain modified SBS;

[0028] Step E4, mix coal tar and toluene, stir at room temperature for 3-3.5 h, stand, filter, rotary evaporate, and dry to obtain pretreated coal tar; in a protective gas atmosphere, heat the pretreated coal tar to 80-85℃, start stirring, continue to heat to 90-100℃, add modified SBS, heat to 130-140℃ at a rate of 2-3℃ / min, then add boron trifluoride, continue to stir for 2-2.5 h to obtain modified coal tar;

[0029] Further, the ratio of the amount of coal tar and toluene is 1-2 g: 2-5 g; the ratio of the amount of pretreated coal tar, modified SBS, and boron trifluoride is 10-15 g: 0.5-0.7 g: 0.2-0.3 g;

[0030] In the reaction process of step E4, first, toluene is mixed with coal tar to remove impurities in the coal tar to obtain pretreated coal tar; then, the pretreated coal tar is modified with modified SBS to obtain modified coal tar;

[0031] The preparation of the auxiliary includes the following steps:

[0032] Step F1, mix expanded graphite and oxidizing agent, heat and stir to obtain product d1; add silane a to solvent 1, adjust the pH with acetic acid, heat and stir, then add a dispersion of product d1, and heat and stir to obtain product d2;

[0033] Step F2, mix product d2 and solvent 2, add meta-chloroperoxybenzoic acid, heat and stir to obtain product d3; mix glass fiber and hydrochloric acid solution, shake in a water bath to obtain pretreated fiber, then wash the surface of the pretreated fiber to neutral, transfer to a lye solution, heat and soak to obtain activated fiber; add the activated fiber to a solution of silane b, heat and stir to obtain product d4;

[0034] Step F3, mix product d3, product d4, DMF, 1, 4-dioxane, and stir to obtain product d5; mix product d5, DMAC, and toluene, add epichlorohydrin, lye 1, stir and heat, then add DMAC, and stir to obtain the auxiliary agent;

[0035] The preparation of the auxiliary agent comprises the following specific steps:

[0036] Step F1, mix expanded graphite and oxidizing agent, and stir at 55-65°C for 10-11h to obtain product d1; add silane a to solvent 1, add acetic acid to adjust pH to 4-4.5, stir at 50-60°C for 3-4h, then add the dispersion of product d1, and stir at 70-75°C for 6-6.5h to obtain product d2;

[0037] Further, the expanded graphite and the oxidizing agent are used in a ratio of 1-2g:13-15mL; the oxidizing agent is a mixture of potassium dichromate, concentrated nitric acid, and concentrated sulfuric acid in a ratio of 10-12g:18-20mL:8-10mL; the silane a, solvent 1, and the dispersion of product d1 are used in a ratio of 23-27g:50-60mL:550-570mL; the solvent 1 is a mixture of ethanol and water in a volume ratio of 1-1.5:1; the volume fraction of ethanol is 95%; the dispersion of product d1 is obtained by adding 2-4g of product d1 to 10-15mL of DMF and ultrasonic dispersion for 30-40min; the silane a is one of 7-octenyltrimethoxysilane, 5-hexenyltrimethoxysilane, and 5-hexenyltriethoxysilane;

[0038] During the reaction of step F1, the expanded graphite is oxidized by the oxidizing agent, and the surface oxygen-containing functional groups increase to obtain product d1; the silane a modifies the expanded graphite with increased surface oxygen-containing functional groups after hydrolysis to obtain expanded graphite with carbon-carbon double bonds on the surface, i.e., product d2;

[0039] Step F2, mix product d2 and solvent 2, stir for 20-30min, add m-chloroperbenzoic acid, and stir at 45-55°C for 4.5-5h to obtain product d3; mix glass fiber and hydrochloric acid solution in a 50-60°C water bath, and shake for 30-35min to obtain pretreated fiber; after washing the surface of the pretreated fiber to neutral, transfer it to lye, and soak at 45-50°C for 2-2.5h to obtain activated fiber; add the activated fiber to the solution of silane b, and stir at 45-50°C for 1.5-2h to obtain product d4;

[0040] Further, the ratio of the use amount of product d2, solvent 2, meta-chloro peroxide benzoic acid is 10-12g: 150-160mL: 25-27g; solvent 2 is DMF and tetrahydrofuran mixed according to the volume ratio of 1.5-2.5:1; the ratio of the use amount of glass fiber, hydrochloric acid solution is 1-2g: 10-12mL; the ratio of the use amount of pretreated fiber, lye is 1-2g: 15-20mL; the ratio of the use amount of activated fiber, silane b solution is 100-105g: 130-140mL; the mass fraction of hydrochloric acid solution is 5-7%; the lye is ammonia solution with pH of 8-8.5; the silane b solution is obtained by stirring 23-25g of silane b, 100-105mL of ethanol and 0.25-0.3g of sodium dodecyl benzene sulfonate at 40-45 DEG C for 2-2.5h; and the silane b is 4-amino-3,3-dimethylbutyl trimethoxysilane;

[0041] In the reaction process of step F2, the carbon-carbon double bond of product d2 is oxidized into an epoxy group to obtain product d3; after the hydrolysis of silane b, the surface of the pretreated and activated glass fiber is modified to obtain glass fiber with an amino group on the surface, i.e., product d4;

[0042] In step F3, product d3, product d4, DMF and 1,4-dioxane are mixed and stirred at 55-65 DEG C for 2-3h to obtain product d5; product d5, DMAC and toluene are mixed and stirred for 1-1.5h, then epoxy chloropropane and lye 1 are added, and the mixture is stirred at 55-65 DEG C for 3-3.5h; then DMAC is added, the temperature is increased to 70-75 DEG C, and the mixture is stirred for 2-3h to obtain the additive;

[0043] Further, the ratio of the use amount of product d3, product d4, DMF and 1,4-dioxane is 14-16g: 24-26g: 100-110mL: 120-130mL; the ratio of the use amount of product d5, total amount of DMAC, toluene, epoxy chloropropane and lye 1 is 50-54g: 250-260mL: 140-150mL: 25-27g: 45-50mL; lye 1 is sodium hydroxide solution with a mass fraction of 30-40%; and the volume ratio of the two times of DMAC added is 2-2.5:1;

[0044] In the reaction process of step F3, the epoxy group of product d3 reacts with the amino group of product d4 to obtain the glass fiber and expanded graphite graft product containing a hydroxyl group, i.e., product d5; the hydroxyl group of product d5 is ring-opened and then ring-closed with epoxy chloropropane to obtain the glass fiber and expanded graphite graft product containing an epoxy group, i.e., the additive;

[0045] The present application has the following beneficial effects: the present application discloses a high and low temperature resistant coal tar pitch-containing asphalt mixture and a preparation method thereof, and the asphalt mixture is prepared from modified coal tar pitch, gravel, additive and mineral powder.

[0046] The modified coal pitch is obtained by modifying the coal pitch with modified SBS, and the modified SBS is obtained by grafting product c5 obtained by reacting 5-amino-2-hydroxycyclohepta-2,4,6-triene-1-ketone, 3-hydroxy-5-nitrothiophene-2-carboxylic acid methyl ester, 4-acetyl-3-nitrobenzoic acid methyl ester and the like with SBS. The combination of 5-amino-2-hydroxycyclohepta-2,4,6-triene-1-ketone and 3-hydroxy-5-nitrothiophene-2-carboxylic acid methyl ester enhances the ultraviolet absorption of the modified coal pitch by forming a larger conjugated system of thiophene and cycloheptatriene, and enhances the ultraviolet resistance of the modified coal pitch. The phenolic hydroxyl group on the cycloheptatriene and the hydroxyl group on the thiophene ring synergistically enhance the oxidation resistance of the modified coal pitch, and thus the modified coal pitch has strong aging resistance. After 4-acetyl-3-nitrobenzoic acid methyl ester participates in the reaction, amino groups are introduced into the modified SBS, which can react with the epoxy groups in the additives to crosslink, thereby enhancing the interfacial bonding force between the glass fibers, expanded graphite and the modified coal pitch in the additives, and improving the comprehensive performance of the asphalt mixture.

[0047] The additive is an expanded graphite-glass fiber grafting product containing epoxy groups obtained by reacting expanded graphite, glass fiber and the like. The additive can enhance the interfacial bonding force between the epoxy groups and the modified coal pitch, which not only helps to inhibit the cracking of the asphalt mixture at low temperature by the glass fibers through the cohesion effect, but also helps to enhance the gripping force of the modified coal pitch on the aggregate and improve the high temperature resistance of the asphalt mixture. In addition, the expanded graphite can form a dense carbon layer by expanding when heated, and has an adsorption effect on the light components in the coal pitch, and has an intramolecular synergistic effect with the heat shielding effect of the glass fibers, which not only has good flame retardant and smoke suppression performance, but also can reduce the release of harmful gases such as polycyclic aromatic hydrocarbons in the modified coal pitch at high temperature, which is beneficial to environmental protection. In addition, the flexibility of the expanded graphite after grafting with the glass fiber can also relieve the low temperature brittleness caused by the rigidity of the glass fiber, and further improve the low temperature resistance of the asphalt mixture. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be described below. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0049] Embodiment 1

[0050] A modified coal pitch, the preparation thereof comprising the following steps:

[0051] Step E1, under nitrogen atmosphere, 3-hydroxy-5-nitrothiophene-2-carboxylic acid methyl ester was added into tetrahydrofuran and stirred to be heated to 80℃, 5-amino-2-hydroxycyclohepta-2,4,6-trien-1-one, zinc chloride were added, constant temperature stirring reaction for 8h to obtain product c1; product c1, DMF, ethanol were mixed, tetrahydroxydiborane and 4,4'-bipyridine were added, stirred at room temperature for 25min to obtain product c2; the amount ratio of 3-hydroxy-5-nitrothiophene-2-carboxylic acid methyl ester, tetrahydrofuran, 5-amino-2-hydroxycyclohepta-2,4,6-trien-1-one, zinc chloride was 22g:85mL:15g:0.4g; the amount ratio of product c1, DMF, ethanol, tetrahydroxydiborane, 4,4'-bipyridine was 40g:60mL:50mL:13g:0.3g; the volume fraction of ethanol was 95%;

[0052] Step E2, under nitrogen atmosphere, 4-acetyl-3-nitrobenzoic acid methyl ester, DMAC, methanol were mixed and stirred for 20min, heated to 80℃, product c2, ammonium sulfate were added, constant temperature stirring reaction for 6.5h to obtain product c3; product c3, DMF, isopropyl alcohol were mixed and stirred for 30min, tin dichloride, dilute hydrochloric acid were added, stirred at 50℃ for 4h to obtain product c4; the amount ratio of 4-acetyl-3-nitrobenzoic acid methyl ester, DMAC, methanol, product c2, ammonium sulfate was 24g:50mL:55mL:38g:0.27g; the amount ratio of product c3, DMF, isopropyl alcohol, tin dichloride, dilute hydrochloric acid was 55g:90mL:50mL:20g:20mL; the mass fraction of dilute hydrochloric acid was 8%;

[0053] Step E3, under nitrogen atmosphere, product c4 was added into anhydrous tetrahydrofuran, anhydrous methanol, stirred for 40min, then methylene triphenyl phosphine was added, stirred at 50℃ under reflux for 6h to obtain product c5; product c5, SBS, solvent a were mixed and stirred under nitrogen atmosphere for 1h, initiator was added, heated to 60℃, stirred for 7.5h to obtain modified SBS; the amount ratio of product c4, anhydrous tetrahydrofuran, anhydrous methanol, methylene triphenyl phosphine was 53g:100mL:60mL:29g; the amount ratio of product c5, SBS, solvent a, initiator was 50g:155g:450mL:1g; solvent a was obtained by mixing toluene and cyclohexane according to a volume ratio of 2:1.5; initiator was obtained by mixing dibenzoyl peroxide and azobisisobutyronitrile according to a mass ratio of 1:1.5;

[0054] Step E4, the coal tar pitch, toluene were mixed, stirred at room temperature for 3h, standing, filtering, rotary evaporation, drying to obtain pretreated coal tar pitch; under nitrogen atmosphere, the pretreated coal tar pitch was heated to 80℃, stirring started, continued to heat to 90℃, added modified SBS, heated to 130℃ at a rate of 2℃ / min, then added boron trifluoride, continued to stir for 2h, to obtain modified coal tar pitch; the amount ratio of coal tar pitch, toluene was 1g:2g; the amount ratio of pretreated coal tar pitch, modified SBS, boron trifluoride was 10g:0.5g:0.2g.

[0055] Example 2

[0056] A modified coal tar pitch, the preparation comprising the following steps:

[0057] Step E1, under nitrogen atmosphere, 3-hydroxy-5-nitrothiophene-2-carboxylic acid methyl ester was added to tetrahydrofuran and stirred to heat to 85℃, 5-amino-2-hydroxycyclohepta-2,4,6-triene-1-ketone, zinc chloride were added, constant temperature stirring reaction for 8.3h to obtain product c1; product c1, DMF, ethanol were mixed, tetrahydroxydiborane and 4,4'-dipyridyl were added, stirred at room temperature for 30min to obtain product c2; the amount ratio of 3-hydroxy-5-nitrothiophene-2-carboxylic acid methyl ester, tetrahydrofuran, 5-amino-2-hydroxycyclohepta-2,4,6-triene-1-ketone, zinc chloride was 23g:90mL:16g:0.5g; the amount ratio of product c1, DMF, ethanol, tetrahydroxydiborane, 4,4'-dipyridyl was 41g:65mL:55mL:14g:0.4g; the volume fraction of ethanol was 95%;

[0058] Step E2, 4-acetyl-3-nitrobenzoic acid methyl ester, DMAC, methanol were mixed under nitrogen atmosphere and stirred for 25min, heated to 83℃, product c2, ammonium sulfate were added, constant temperature stirring reaction for 7.0h to obtain product c3; product c3, DMF, isopropyl alcohol were mixed and stirred for 35min, tin dichloride, dilute hydrochloric acid were added, stirred at 55℃ for 4.3h to obtain product c4; the amount ratio of 4-acetyl-3-nitrobenzoic acid methyl ester, DMAC, methanol, product c2, ammonium sulfate was 25g:55mL:60mL:39g:0.29g; the amount ratio of product c3, DMF, isopropyl alcohol, tin dichloride, dilute hydrochloric acid was 56g:95mL:55mL:21g:25mL; the mass fraction of dilute hydrochloric acid was 9%;

[0059] Step E3, product c4 was added into anhydrous tetrahydrofuran, anhydrous methanol under nitrogen atmosphere, stirred for 43 min, then methylene triphenyl phosphine was added, stirred at 53℃ under reflux for 6.5h to obtain product c5; product c5, SBS, solvent a were mixed under nitrogen atmosphere and stirred for 1.3h, initiator was added, heated to 65℃, stirred for 7.8h to obtain modified SBS; the amount ratio of product c4, anhydrous tetrahydrofuran, anhydrous methanol, methylene triphenyl phosphine was 54g: 105mL: 65mL: 30g; the amount ratio of product c5, SBS, solvent a, initiator was 51g: 160g: 480mL: 1.3g; solvent a was obtained by mixing toluene and cyclohexane according to the volume ratio of 2.3: 1.5; initiator was obtained by mixing dibenzoyl peroxide and azobisisobutyronitrile according to the mass ratio of 1: 1.5;

[0060] Step E4, coal tar pitch and toluene were mixed, stirred at room temperature for 3.3h, then placed, filtered, rotary evaporated and dried to obtain pretreated coal tar pitch; the pretreated coal tar pitch was heated to 83℃ under nitrogen atmosphere, then stirred, heated to 95℃, then modified SBS was added, heated to 135℃ at a rate of 2℃ / min, then boron trifluoride was added, stirred for 2.3h to obtain modified coal tar pitch; the amount ratio of coal tar pitch and toluene was 1.5g: 2.5g; the amount ratio of pretreated coal tar pitch, modified SBS and boron trifluoride was 13g: 0.6g: 0.25g.

[0061] Example 3

[0062] A modified coal tar pitch, the preparation comprising the following steps:

[0063] Step E1, 3-hydroxy-5-nitrothiophene-2-carboxylic acid methyl ester was added into tetrahydrofuran under nitrogen atmosphere, stirred and heated to 90℃, then 5-amino-2-hydroxycyclohepta-2,4,6-triene-1-one and zinc chloride were added, stirred at constant temperature for 8.5h to obtain product c1; product c1, DMF and ethanol were mixed, then tetrahydroxydiborane and 4,4'-bipyridine were added, stirred at room temperature for 35min to obtain product c2; the amount ratio of 3-hydroxy-5-nitrothiophene-2-carboxylic acid methyl ester, tetrahydrofuran, 5-amino-2-hydroxycyclohepta-2,4,6-triene-1-one and zinc chloride was 24g: 95mL: 17g: 0.6g; the amount ratio of product c1, DMF, ethanol, tetrahydroxydiborane and 4,4'-bipyridine was 42g: 70mL: 60mL: 15g: 0.5g; the volume fraction of ethanol was 95%;

[0064] Step E2, mixing 4-acetyl-3-nitrobenzoic acid methyl ester, DMAC, methanol under nitrogen atmosphere, stirring for 30 min, heating to 85℃, adding product c2, ammonium sulfate, constant temperature stirring for 7.5 h to obtain product c3; mixing product c3, DMF, isopropyl alcohol, stirring for 40 min, adding tin dichloride, dilute hydrochloric acid, stirring at 60℃ for 4.5 h to obtain product c4; the amount ratio of 4-acetyl-3-nitrobenzoic acid methyl ester, DMAC, methanol, product c2, ammonium sulfate is 26 g: 60 mL: 65 mL: 40 g: 0.31 g; the amount ratio of product c3, DMF, isopropyl alcohol, tin dichloride, dilute hydrochloric acid is 57 g: 100 mL: 60 mL: 22 g: 30 mL; the mass fraction of dilute hydrochloric acid is 10%;

[0065] Step E3, adding product c4 into anhydrous tetrahydrofuran, anhydrous methanol under nitrogen atmosphere, stirring for 45 min, then adding methylene triphenyl phosphine, refluxing and stirring at 55℃ for 7 h to obtain product c5; mixing product c5, SBS, solvent a under nitrogen atmosphere, stirring for 1.5 h, adding initiator, heating to 70℃, stirring for 8 h to obtain modified SBS; the amount ratio of product c4, anhydrous tetrahydrofuran, anhydrous methanol, methylene triphenyl phosphine is 55 g: 110 mL: 70 mL: 31 g; the amount ratio of product c5, SBS, solvent a, initiator is 52 g: 165 g: 550 mL: 1.5 g; solvent a is obtained by mixing toluene and cyclohexane according to a volume ratio of 2.5: 1.5; the initiator is obtained by mixing dibenzoyl peroxide and azobisisobutyronitrile according to a mass ratio of 1: 2;

[0066] Step E4, mixing coal tar pitch and toluene, stirring at room temperature for 3.5 h, standing, filtering, rotary evaporation, drying to obtain pretreated coal tar pitch; under nitrogen atmosphere, heating pretreated coal tar pitch to 85℃, starting stirring, continuing heating to 100℃, adding modified SBS, heating to 140℃ at a rate of 2℃ / min, then adding boron trifluoride, continuing stirring for 2.5 h to obtain modified coal tar pitch; the amount ratio of coal tar pitch and toluene is 2 g: 5 g; the amount ratio of pretreated coal tar pitch, modified SBS, boron trifluoride is 15 g: 0.7 g: 0.3 g.

[0067] Example 4

[0068] An auxiliary, the preparation comprising the following steps:

[0069] Step F1, mixing the expanded graphite and oxidant, stirring at 55℃ for 10h to obtain product d1; adding 5-hexenyltrimethoxysilane into solvent 1, adding acetic acid to adjust pH to 4.2, stirring at 50℃ for 3h, then adding the dispersion of product d1, stirring at 70℃ for 6h to obtain product d2; the expanded graphite and oxidant are mixed in a ratio of 1g:13mL; the oxidant is a mixture of potassium dichromate, concentrated nitric acid and concentrated sulfuric acid in a ratio of 10g:18mL:8mL; the mass fraction of the concentrated nitric acid and the concentrated sulfuric acid is both 98%; the 5-hexenyltrimethoxysilane, solvent 1 and the dispersion of product d1 are mixed in a ratio of 23g:50mL:550mL; the solvent 1 is a mixture of ethanol and water in a volume ratio of 1:1; the volume fraction of the ethanol is 95%; the dispersion of product d1 is obtained by adding 2g of product d1 into 10mL of DMF and ultrasonic dispersion for 30min;

[0070] Step F2, mixing product d2 and solvent 2, stirring for 20min, adding m-chloroperoxybenzoic acid, stirring at 45℃ for 4.5h to obtain product d3; mixing glass fiber (supplier: Shandong Tonghui Glass Fiber Co., Ltd., 6mm) and hydrochloric acid solution in a 50℃ water bath for 30min to obtain pretreated fiber, then transferring the pretreated fiber to the lye, soaking at 45℃ for 2h to obtain activated fiber; adding the activated fiber into the solution of silane b, stirring at 45℃ for 1.5h to obtain product d4; the product d2, solvent 2 and m-chloroperoxybenzoic acid are mixed in a ratio of 10g:150mL:25g; the solvent 2 is a mixture of DMF and tetrahydrofuran in a volume ratio of 1.5:1; the glass fiber and the hydrochloric acid solution are mixed in a ratio of 1g:10mL; the pretreated fiber and the lye are mixed in a ratio of 1g:15mL; the activated fiber and the solution of silane b are mixed in a ratio of 100g:130mL; the mass fraction of the hydrochloric acid solution is 5%; the lye is an ammonia solution with pH of 8.2; the solution of silane b is obtained by stirring 23g of silane b, 100mL of ethanol and 0.25g of sodium dodecylbenzenesulfonate at 40℃ for 2h; the volume fraction of the ethanol is 95%; the silane b is 4-amino-3,3-dimethylbutyltrimethoxysilane;

[0071] Step F3, product d3, product d4, DMF, 1,4-dioxane were mixed and stirred at 55°C for 2h to obtain product d5; product d5, DMAC, toluene were mixed and stirred for 1h, then epichlorohydrin, lye 1 were added, and stirred at 55°C for 3h, then DMAC was added, and the temperature was increased to 70°C, and stirred for 2h to obtain the adjuvant; the amount ratio of product d3, product d4, DMF, 1,4-dioxane was 14g:24g:100mL:120mL; the amount ratio of product d5, total amount of DMAC, toluene, epichlorohydrin, lye 1 was 50g:250mL:140mL:25g:45mL; lye 1 was a 30% sodium hydroxide solution; the volume ratio of the two times of DMAC was 2:1.

[0072] Example 5

[0073] An adjuvant, the preparation comprising the following steps:

[0074] Step F1, expandable graphite, oxidant were mixed and stirred at 60°C for 10.5h to obtain product d1; 5-hexenyl triethoxysilane was added to solvent 1, acetic acid was added to adjust the pH to 4.2, and stirred at 55°C for 3.5h, then the dispersion of product d1 was added, and stirred at 73°C for 6.3h to obtain product d2; the amount ratio of expandable graphite, oxidant was 1.5g:14mL; the oxidant was potassium dichromate, concentrated nitric acid, concentrated sulfuric acid mixed in a proportion of 11g:19mL:9mL; the amount ratio of 5-hexenyl triethoxysilane, solvent 1, dispersion of product d1 was 25g:55mL:560mL; solvent 1 was ethanol and water mixed in a volume ratio of 1.3:1; the volume fraction of ethanol was 95%; the dispersion of product d1 was obtained by adding 3g of product d1 to 13mL of DMF and ultrasonic dispersion for 35min;

[0075] Step F2, product d2, solvent 2 were mixed and stirred for 25 min, m-chloroperbenzoic acid was added, and the reaction was stirred at 50°C for 4.8 h to obtain product d3; glass fiber (supplier: Shandong Tonghui Glass Fiber Co., Ltd., 9 mm) and hydrochloric acid solution were mixed in a water bath at 55°C and shaken for 33 min to obtain pretreated fiber, which was then transferred to a lye solution and soaked at 48°C for 2.3 h to obtain activated fiber; the activated fiber was added to a solution of silane b and stirred at 48°C for 1.8 h to obtain product d4; the amount ratio of product d2, solvent 2, and m-chloroperbenzoic acid was 11 g:155 mL:26 g; solvent 2 was a mixture of DMF and tetrahydrofuran in a volume ratio of 2.0:1; the amount ratio of glass fiber and hydrochloric acid solution was 1.5 g:11 mL; the amount ratio of pretreated fiber and lye was 1.5 g:18 mL; the amount ratio of activated fiber and solution of silane b was 103 g:135 mL; the mass fraction of hydrochloric acid solution was 6%; the lye was an ammonia solution with a pH of 8.3; the solution of silane b was obtained by stirring 24 g of silane b, 103 mL of ethanol, and 0.28 g of sodium dodecylbenzenesulfonate at 43°C for 2.3 h; the volume fraction of ethanol was 95%; and silane b was 4-amino-3,3-dimethylbutyl trimethoxysilane;

[0076] Step F3, product d3, product d4, DMF, and 1,4-dioxane were mixed and stirred at 60°C for 2.5 h to obtain product d5; product d5, DMAC, and toluene were mixed and stirred for 1.3 h, epoxy chloropropane and lye 1 were added, and the reaction was stirred at 60°C for 3.3 h; then DMAC was added, the temperature was raised to 73°C, and the reaction was stirred for 2.5 h to obtain an adjuvant; the amount ratio of product d3, product d4, DMF, and 1,4-dioxane was 15 g:25 g:105 mL:125 mL; the amount ratio of product d5, total amount of DMAC, toluene, epoxy chloropropane, and lye 1 was 52 g:255 mL:145 mL:26 g:48 mL; lye 1 was a 35% sodium hydroxide solution; and the volume ratio of the two times of DMAC added was 2.3:1.

[0077] Example 6

[0078] An adjuvant, the preparation of which comprises the following steps:

[0079] Step F1, mixing the expanded graphite and oxidant, stirring at 65℃ for 11h to obtain product d1; adding 7-octenyltrimethoxysilane into solvent 1, adding acetic acid to adjust pH to 4.4, stirring at 60℃ for 4h, then adding the dispersion of product d1, stirring at 75℃ for 6.5h to obtain product d2; the expanded graphite and oxidant are used in a ratio of 2g:15mL; the oxidant is a mixture of potassium dichromate, concentrated nitric acid and concentrated sulfuric acid in a ratio of 12g:20mL:10mL; 7-octenyltrimethoxysilane, solvent 1 and the dispersion of product d1 are used in a ratio of 27g:60mL:570mL; solvent 1 is a mixture of ethanol and water in a volume ratio of 1.5:1; the volume fraction of ethanol is 95%; the dispersion of product d1 is obtained by adding 4g of product d1 into 15mL of DMF and ultrasonic dispersion for 40min;

[0080] Step F2, mixing product d2 and solvent 2, stirring for 30min, adding m-chloroperoxybenzoic acid, stirring at 55℃ for 5h to obtain product d3; mixing glass fiber (supplier: Shandong Tonghui Glass Fiber Co., Ltd., 12mm) and hydrochloric acid solution in a 60℃ water bath for 35min to obtain pretreated fiber, then transferring the pretreated fiber to the lye, soaking at 50℃ for 2.5h to obtain activated fiber; adding the activated fiber into the solution of silane b, stirring at 50℃ for 2h to obtain product d4; product d2, solvent 2 and m-chloroperoxybenzoic acid are used in a ratio of 12g:160mL:27g; solvent 2 is a mixture of DMF and tetrahydrofuran in a volume ratio of 2.5:1; the glass fiber and hydrochloric acid solution are used in a ratio of 2g:12mL; the pretreated fiber and lye are used in a ratio of 2g:20mL; the activated fiber and the solution of silane b are used in a ratio of 105g:140mL; the mass fraction of the hydrochloric acid solution is 7%; the lye is an ammonia solution with a pH of 8.4; the solution of silane b is obtained by stirring 25g of silane b, 105mL of ethanol and 0.3g of sodium dodecylbenzenesulfonate at 45℃ for 2.5h; the volume fraction of ethanol is 95%; silane b is 4-amino-3,3-dimethylbutyltrimethoxysilane;

[0081] Step F3, product d3, product d4, DMF, 1,4-dioxane are mixed, and stirred at 65℃ for 3h to obtain product d5; product d5, DMAC, toluene are mixed and stirred for 1.5h, then epoxy chloropropane, lye 1 are added, and stirred at 65℃ for 3.5h, then DMAC is added, and the temperature is increased to 75℃, and stirred for 3h to obtain the additive; the amount ratio of product d3, product d4, DMF, 1,4-dioxane is 16g:26g:110mL:130mL; the amount ratio of product d5, total amount of DMAC, toluene, epoxy chloropropane, lye 1 is 54g:260mL:150mL:27g:50mL; lye 1 is a sodium hydroxide solution with a mass fraction of 40%; the volume ratio of DMAC added before and after is 2.5:1.

[0082] Example 7

[0083] A high and low temperature resistant coal-tar-containing asphalt mixture, comprising the following raw materials in parts by weight: modified coal tar 20 parts, gravel 40 parts, additive 10 parts, and mineral powder 8 parts; the gravel is granite with a particle size range of 8mm, obtained by roller crusher; the mineral powder is mineral particles with a particle size of 0.6mm, obtained by jaw crusher;

[0084] The preparation of the high and low temperature resistant coal-tar-containing asphalt mixture comprises the following steps:

[0085] The gravel and half of the mineral powder are stirred at 175℃ for 8s to obtain a mixture; the temperature of the mixture is adjusted to 170℃, and the modified coal tar obtained in Example 1 is sprayed into the mixture in two equal amounts with stirring, and continues to be stirred for 15s, the temperature is adjusted to 160℃, the additive obtained in Example 4 and the other half of the mineral powder are added, and continues to be stirred for 4min, and the material is discharged to obtain the asphalt mixture; the time interval between the two times of adding the modified coal tar is 6s, and the spraying rate of the modified coal tar is 0.6kg / s.

[0086] Example 8

[0087] A high and low temperature resistant coal-tar-containing asphalt mixture, comprising the following raw materials in parts by weight: modified coal tar 20 parts, gravel 40 parts, additive 10 parts, and mineral powder 8 parts; the gravel is granite with a particle size range of 8mm, obtained by roller crusher; the mineral powder is mineral particles with a particle size of 0.6mm, obtained by jaw crusher;

[0088] The preparation of the high and low temperature resistant coal-tar-containing asphalt mixture comprises the following steps:

[0089] The mixture was prepared by mixing the crushed stone and half of the mineral powder at 180°C for 9s; the temperature of the mixture was adjusted to 175°C, and the modified coal pitch obtained in Example 2 was sprayed into the mixture in two equal portions under stirring, and the stirring was continued for 18s, the temperature was adjusted to 165°C, the additive obtained in Example 5 and the other half of the mineral powder were added, and the stirring was continued for 5min, and the mixture was discharged to obtain the asphalt mixture; the interval between the two times of adding the modified coal pitch was 8s, and the spraying rate of the modified coal pitch was 0.7kg / s.

[0090] Example 9

[0091] A high and low temperature resistant asphalt mixture containing coal pitch, comprising the following raw materials in parts by weight: modified coal pitch 25 parts, crushed stone 45 parts, additive 15 parts, and mineral powder 10 parts; the crushed stone is granite with a particle size range of 8mm, and is obtained by crushing with a roller crusher; the mineral powder is mineral particles with a particle size of 0.6mm, and is obtained by crushing with a jaw crusher.

[0092] The high and low temperature resistant asphalt mixture containing coal pitch is prepared by the following steps:

[0093] The mixture was prepared by mixing the crushed stone and half of the mineral powder at 185°C for 10s; the temperature of the mixture was adjusted to 180°C, and the modified coal pitch obtained in Example 3 was sprayed into the mixture in two equal portions under stirring, and the stirring was continued for 20s, the temperature was adjusted to 170°C, the additive obtained in Example 6 and the other half of the mineral powder were added, and the stirring was continued for 6min, and the mixture was discharged to obtain the asphalt mixture; the interval between the two times of adding the modified coal pitch was 10s, and the spraying rate of the modified coal pitch was 0.8kg / s.

[0094] Comparative Example 1

[0095] Comparing with Example 9, the 5-amino-2-hydroxycyclohepta-2,4,6-triene-1-ketone in the preparation process of the modified coal pitch was replaced by p-aminophenol, and the rest was exactly the same as Example 9 to prepare the asphalt mixture containing coal pitch.

[0096] Comparative Example 2

[0097] Comparing with Example 9, the 3-hydroxy-5-nitrothiophene-2-carboxylic acid methyl ester in the preparation process of the modified coal pitch was replaced by 5-nitro-2-thiophene carboxylic acid ethyl ester, and the rest was exactly the same as Example 9 to prepare the asphalt mixture containing coal pitch.

[0098] Comparative Example 3

[0099] Comparing with Example 9, the 3-hydroxy-5-nitrothiophene-2-carboxylic acid methyl ester in the preparation process of the modified coal pitch was replaced by 2-hydroxy-5-nitrobenzoic acid methyl ester, and the rest was exactly the same as Example 9 to prepare the asphalt mixture containing coal pitch.

[0100] Comparative Example 4

[0101] Comparing with Example 9, the product c5 used in the preparation of modified coal pitch was replaced by product c3, and the rest was exactly the same as Example 9, to prepare coal pitch-containing asphalt mixture.

[0102] Comparative Example 5

[0103] Comparing with Example 9, the auxiliary was replaced by product d5, and the rest was exactly the same as Example 9, to prepare coal pitch-containing asphalt mixture.

[0104] Comparative Example 6

[0105] Comparing with Example 9, the auxiliary was replaced by product d3, and the rest was exactly the same as Example 9, to prepare coal pitch-containing asphalt mixture.

[0106] Comparative Example 7

[0107] Comparing with Example 9, the auxiliary was replaced by product d4, and the rest was exactly the same as Example 9, to prepare coal pitch-containing asphalt mixture.

[0108] The coal pitch-containing asphalt mixture prepared by the present application was further tested for its effects, and the results are as follows.

[0109] Low-temperature bending failure test: the asphalt mixture was prepared into test pieces (specification: 250 mm x 30 mm x 35 mm), 3 parallel test pieces were cooled to -15℃, and then loaded to break at a rate of 50 mm / min, the failure strain (uε) was recorded, and the average value of 3 parallel test pieces was taken as the failure strain (uε) value, to evaluate the low-temperature resistance;

[0110] Rutting test: the obtained asphalt mixture was prepared into test pieces (specification: 300 mm x 300 mm x 50 mm), the repeated action of vehicle load was simulated, the permanent deformation rate of the test pieces (the average value of 3 parallel test pieces was taken as the permanent deformation rate value) was determined by wheel rolling test at 60℃ (wheel rolling speed was 42 times / min, time was 1 h, and 3 parallel test pieces were used), i.e. dynamic stability (times / mm), to evaluate the high-temperature resistance;

[0111] Horizontal-vertical burning test: referring to UL94, the obtained asphalt mixture was prepared into test pieces with a specification of 100 mm x 10 mm x 3 mm, and horizontal-vertical test was carried out, and the flame retardant grade was recorded; the grading standard of flame retardant grade was as follows: V-0 grade: the test piece self-extinguished within 10 seconds without dripping to ignite the cotton pad; V-1 grade: the test piece self-extinguished within 30 seconds without dripping to ignite the cotton pad; V-2 grade: the test piece self-extinguished within 30 seconds with dripping to ignite the cotton pad;

[0112] Smoke density box test: ignite the obtained asphalt mixture in a closed box, measure the smoke density by light beam attenuation, record the maximum smoke density; smoke density grade: first grade low smoke: maximum smoke density≤150; second grade low smoke: 150<maximum smoke density<200; third grade low smoke: maximum smoke density>200;

[0113] Preparation of test piece A: the obtained asphalt mixture is made into a size of 100mmx100mmx50mm, then a wheel roller forming machine (pressure 0.7±0.05MPa) is used to roll back and forth 12 times, and test piece A is obtained after 24h room temperature cooling;

[0114] Anti-ultraviolet test: prepare test piece A, use UVA-340 lamp tube, irradiate under the condition of radiation intensity 0.76W / m 2 @340nm, temperature 60℃ for 8h, then condense at 50℃ for 4h, the total cycle time of irradiation and condensation is 600h, measure the viscosity growth rate at 60℃ to evaluate the anti-ultraviolet property of the asphalt mixture;

[0115] Anti-oxidation test: prepare test piece A, place 3 parallel test pieces A under the condition of 163±0.5℃, air flow 4000mL / min for 85min, measure the mass loss rate, take the average value of the 3 parallel test pieces as the mass loss rate value to evaluate the anti-oxidation property of the asphalt mixture;

[0116] The results are recorded in Table 1;

[0117] Table 1: test results

[0118]

[0119] According to the data in Table 1, the asphalt mixture of the present application has strong low-temperature resistance, high-temperature resistance, flame-retardant smoke suppression, ultraviolet resistance and oxidation resistance. Comparison of Example 9 and Comparative Example 1 shows that replacing 5-amino-2-hydroxycyclohepta-2,4,6-triene-1-ketone in the preparation process of modified coal tar pitch with p-aminophenol increases the 60℃ viscosity growth rate, and the synergistic enhancement of asphalt mixture ultraviolet resistance decreases. Comparison of Example 9 and Comparative Example 2 shows that replacing 3-hydroxy-5-nitrothiophene-2-carboxylic acid methyl ester in the preparation process of modified coal tar pitch with 5-nitro-2-thiophene carboxylic acid ethyl ester increases the mass loss rate, and the oxidation resistance of the asphalt mixture decreases. Comparison of Example 9 and Comparative Example 3 shows that replacing 3-hydroxy-5-nitrothiophene-2-carboxylic acid methyl ester in the preparation process of modified coal tar pitch with 2-hydroxy-5-nitrobenzoic acid methyl ester decreases the synergistic enhancement of asphalt mixture ultraviolet resistance. Comparison of Example 9 and Comparative Example 4 shows that compared with Example 9, replacing product c4 used in the preparation of product c5 in the preparation process of modified coal tar pitch with product c3, i.e. replacing the amino group on product c5 with a nitro group, makes the modified coal tar pitch unable to react with the epoxy group in the additive, the interfacial bonding force between the modified coal tar pitch and the glass fiber and expanded graphite in the additive decreases, resulting in a decrease in the low-temperature resistance, high-temperature resistance, flame-retardant smoke suppression, ultraviolet resistance and oxidation resistance of the asphalt mixture. Comparison of Example 9 and Comparative Example 5 shows that compared with Example 9, replacing the additive with product d5, i.e. hydroxyl-containing expanded graphite-glass fiber grafted product, the interfacial bonding force between the glass fiber and expanded graphite in the additive and the modified coal tar pitch decreases, resulting in a decrease in the low-temperature resistance, high-temperature resistance, flame-retardant smoke suppression, ultraviolet resistance and oxidation resistance of the asphalt mixture. Comparison of Example 9 and Comparative Example 6 shows that replacing the additive with product d3, i.e. surface containing epoxy group expanded graphite, cannot synergistically enhance the flame-retardant smoke suppression with glass fiber, and the ability to improve the high and low temperature resistance of the asphalt mixture decreases. Comparison of Example 9 and Comparative Example 7 shows that replacing the additive with product d4, i.e. surface containing amino group glass fiber, the flame-retardant smoke suppression decreases more, the interfacial bonding force with the modified coal tar pitch decreases, and the low-temperature resistance, high-temperature resistance, ultraviolet resistance and oxidation resistance of the asphalt mixture all decrease.

[0120] The above merely illustrates and describes the present application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace, without departing from the concept of the present application or exceeding the scope defined by the present application.

Claims

1. A coal tar pitch resistant asphalt mixture, characterized in that: The raw materials include the following parts by weight: 20-25 parts modified coal tar pitch, 40-45 parts crushed stone, 10-15 parts additives, and 8-10 parts mineral powder; Step E1: In a protective gas atmosphere, methyl carboxylate is added to tetrahydrofuran and stirred and heated. Then, aminocycloheptatriene and zinc chloride are added and stirred to obtain product c1. Product c1, DMF and ethanol are mixed, and a reducing agent and catalyst are added and stirred to obtain product c2. Step E2: Methyl benzoate, DMAC, and methanol are mixed in a protective gas atmosphere, heated, and product c2 and ammonium sulfate are added. The mixture is stirred to obtain product c3. Product c3, DMF, and isopropanol were mixed, and tin dichloride and dilute hydrochloric acid were added. The mixture was heated and stirred to obtain product c4. Step E3: Add product c4 to anhydrous tetrahydrofuran and anhydrous methanol under a protective gas atmosphere, stir, add methylene triphenylphosphine, heat and reflux and stir to obtain product c5; mix product c5, SBS and solvent a under a protective gas atmosphere, add initiator, heat and stir to obtain modified SBS. Step E4: Mix coal tar pitch and toluene, stir at room temperature to obtain pretreated coal tar pitch; heat the pretreated coal tar pitch in a protective gas atmosphere, start stirring, continue heating, add modified SBS, heat again and add boron trifluoride, continue stirring to obtain modified coal tar pitch.

2. The asphalt mixture resistant to high and low temperatures containing coal tar pitch according to claim 1, characterized in that: In step E1, the methyl carboxylate is methyl 3-hydroxy-5-nitrothiophene-2-carboxylate; the amino-containing cycloheptatriene is 5-amino-2-hydroxycycloheptatriene-2,4,6-trien-1-one.

3. The asphalt mixture resistant to high and low temperatures containing coal tar pitch according to claim 1, characterized in that: In step E2, methyl benzoate is methyl 4-acetyl-3-nitrobenzoate.

4. The asphalt mixture resistant to high and low temperatures containing coal tar pitch according to claim 1, characterized in that: In step E3, solvent a is obtained by mixing toluene and cyclohexane in a volume ratio of 2-2.5:1.5; the initiator is obtained by mixing benzoyl peroxide and azobisisobutyronitrile in a mass ratio of 1:1.5-2.

5. The asphalt mixture resistant to high and low temperatures containing coal tar pitch according to claim 1, characterized in that: The crushed stone is granite with a particle size range of 5-10mm, obtained by crushing with a roller crusher; the ore powder is ore particles with a particle size of 0.5-0.8mm, obtained by crushing with a jaw crusher.

6. The asphalt mixture resistant to high and low temperatures containing coal tar pitch according to claim 1, characterized in that: The preparation of the auxiliary agent includes the following steps: Step F1: Mix expanded graphite and oxidant, heat and stir to obtain product d1; add silane a to solvent 1, add acetic acid to adjust pH, heat and stir, add the dispersion of product d1, heat and stir to obtain product d2. Step F2: Mix product d2 and solvent 2, add m-chloroperoxybenzoic acid, heat and stir to obtain product d3; mix glass fiber and hydrochloric acid solution and shake in a water bath to obtain pretreated fiber; wash the surface of the pretreated fiber with water until neutral, transfer it to alkaline solution, heat and soak to obtain activated fiber; add the activated fiber to a solution of silane b, heat and stir to obtain product d4. Step F3: Mix product d3, product d4, DMF, and 1,4-dioxane, heat and stir to obtain product d5; mix product d5, DMAC, and toluene, add epichlorohydrin and alkali solution 1, heat and stir, then add DMAC, heat and stir to obtain the additive.

7. The asphalt mixture resistant to high and low temperatures containing coal tar pitch according to claim 6, characterized in that: In step F1, the oxidant is obtained by mixing potassium dichromate, concentrated nitric acid, and concentrated sulfuric acid in a ratio of 10-12g: 18-20mL: 8-10mL; the dispersion of product d1 is obtained by adding 2-4g of product d1 to 10-15mL of DMF and ultrasonically dispersing for 30-40min; silane a is one of 7-octenyltrimethoxysilane, 5-hexenyltrimethoxysilane, and 5-hexenyltriethoxysilane.

8. The asphalt mixture resistant to high and low temperatures containing coal tar pitch according to claim 6, characterized in that: In step F2, the solution of silane b is obtained by stirring 23-25g of silane b, 100-105mL of ethanol and 0.25-0.3g of sodium dodecylbenzenesulfonate at 40-45℃ for 2-2.5h; silane b is 4-amino-3,3-dimethylbutyltrimethoxysilane.

9. A method for preparing a high- and low-temperature resistant coal tar pitch mixture according to any one of claims 1-8, characterized in that: The process includes the following steps: mixing crushed stone and half of the mineral powder at 175-185℃ for 8-10 seconds to obtain a mixture; adjusting the temperature of the mixture to 170-180℃, and spraying the modified coal tar pitch into the mixture in equal amounts twice while stirring, continuing to stir for 15-20 seconds, adjusting the temperature to 160-170℃, adding the additives and the other half of the mineral powder, continuing to stir for 4-6 minutes, and then discharging to obtain the asphalt mixture.

10. The method for preparing a high and low temperature resistant coal tar pitch asphalt mixture according to claim 9, characterized in that: The time interval between the two additions of modified coal tar pitch is 6-10 seconds, and the spraying rate of modified coal tar pitch is 0.6-0.8 kg / s.

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