Anti-rutting enhanced epoxy asphalt mixture and preparation method thereof

Abstract

The invention discloses an anti-rut enhanced epoxy asphalt mixture and a preparation method thereof, belongs to the technical field of asphalt mixture processing, and is used for solving the technical problem that the anti-rut performance, the water stability and the low temperature resistance of an asphalt mixture in the prior art need to be further improved. The modified asphalt is prepared from the following components in parts by weight: 16 to 20 parts of matrix asphalt, 0.8 to 1 part of additive, 4 to 6 parts of reinforced elastomer, 3 to 5 parts of epoxy modified polysiloxane, 4 to 5 parts of modified reinforced fiber and 65 to 75 parts of aggregate, according to the invention, the asphalt mixture composed of the matrix asphalt and the aggregate is reinforced by the reinforced elastomer, the epoxy modified polysiloxane and the modified reinforced fibers, so that the rutting resistance of the epoxy asphalt mixture is effectively improved, and the water stability and low temperature resistance of the epoxy asphalt mixture are also improved.

Description

Technical Field

[0001] The invention relates to the technical field of asphalt mixture processing, and in particular to an anti-rutting enhanced epoxy asphalt mixture and a preparation method thereof. Background Art

[0002] Asphalt mixture is a general term for a mixture of coarse aggregate, fine aggregate and other mineral materials mixed with asphalt. Asphalt mixture has excellent mechanical properties and can withstand heavy vehicle loads and repeated traffic pressure. Its excellent anti-wear and anti-rutting capabilities make the road smoother and improve driving comfort and safety. In addition, asphalt mixture also has good adhesion and can firmly combine different materials together to enhance the integrity and stability of the road surface.

[0003] Prior art, a Chinese invention patent with publication number CN115819015A, discloses a rutting-resistant drainage asphalt mixture, the raw material components are as follows: epoxy asphalt, mineral fiber, styrene, butadiene, initiator, polymerization monomer, carboxyl silicone oil, n-hexylamine, dithiothreitol, carbonate solution and calcium lactate, the porosity of the prepared asphalt mixture is not affected, and the mechanical properties and rutting resistance are significantly improved compared with ordinary asphalt, nano calcium carbonate and aggregate as reinforcing components are also fixed in the asphalt mixture, in rainy and windy weather, the reinforcing components are not easy to scatter, the network skeleton structure formed by the styrene-butadiene-polymerization monomer copolymer in the asphalt mixture is stable, and the copolymer retains the heat insulation, shockproof and flame retardant properties of polystyrene, the obtained asphalt pavement has good mechanical properties and is not easy to crack under vehicle load.

[0004] However, asphalt mixtures in the prior art are usually mixed and bonded with various mixtures using asphalt as a binder to bond the various parts together, but the bonding strength of asphalt itself to the various mixtures is limited, and the elastic modulus of asphalt itself is low, resulting in poor deformation recovery ability of the asphalt mixture, and the anti-rutting performance of the asphalt mixture needs to be further improved; on the other hand, due to the hygroscopicity and moisture retention of the asphalt mixture, moisture can easily penetrate into the mixture, causing the adhesion between asphalt and aggregate to decrease, resulting in the shedding of the asphalt film and damage to the mixture structure, and, in a low temperature environment, asphalt is easy to harden, resulting in an increase in its elastic modulus but a decrease in toughness, which makes the asphalt mixture prone to cracking and breaking under low temperature conditions, and the water stability and low temperature resistance of the asphalt mixture need to be further improved.

[0005] In view of the technical defects in this aspect, a solution is now proposed. Summary of the invention

[0006] The purpose of the present invention is to provide an anti-rutting enhanced epoxy asphalt mixture and a preparation method thereof, so as to solve the technical problem in the prior art that the anti-rutting performance, water stability and low temperature resistance of asphalt mixtures need to be further improved.

[0007] The object of the present invention can be achieved by the following technical scheme: an anti-rutting reinforced epoxy asphalt mixture, comprising the following components by weight: 16-20 parts of base asphalt, 0.8-1 parts of additive, 4-6 parts of reinforcing elastomer, 3-5 parts of epoxy-modified polysiloxane, 4-5 parts of modified reinforcing fiber and 65-75 parts of aggregate;

[0008] The preparation method of the epoxy-modified polysiloxane is as follows: 3-glycidyloxypropylmethyldiethoxysilane, diphenyldihydroxysilane, 3-glycidyloxypropylmethyltriethoxysilane and a catalyst are added into a nitrogen-protected reactor and stirred, the temperature of the reactor is increased to 75-85° C., the reaction is carried out by heat preservation for 6-8 hours, and post-treatment is performed to obtain the epoxy-modified polysiloxane.

[0009] The synthetic reaction formula of epoxy-modified polysiloxane is:

[0010]

[0011] The synthetic reaction mechanism of epoxy-modified polysiloxane is:

[0012] In an alkaline environment, the epoxy group can remain stable. With sodium hydroxide as a catalyst, the ethoxy group of ethoxysilane is hydrolyzed to form silanol groups, and the silanol groups between molecules undergo a dehydration condensation reaction to generate new silicon-oxygen-silicon bonds, forming epoxy-modified polysiloxanes with aromatic rings and a large number of epoxy groups modifying long polysiloxane chains. The aromatic rings are used as rigid groups and polysiloxanes are used as flexible chain segments, so that the epoxy-modified polysiloxanes combine the rigidity of epoxy resins and the flexibility of polysiloxanes.

[0013] Furthermore, the weight ratio of the 3-glycidyloxypropylmethyldiethoxysilane, diphenyldihydroxysilane, 3-glycidyloxypropylmethyltriethoxysilane and the catalyst is 5-7:3-5:2-3:1, the catalyst is an 8-12wt% sodium hydroxide solution, and the post-treatment comprises: after the reaction is completed, the temperature of the reactor is lowered to room temperature, purified water is added to the reactor, stirred for 10-15 minutes, allowed to stand to separate the water phase, the organic layer is washed with purified water until neutral and then transferred to the reactor, the temperature of the reactor is raised to 80-90°C, and low-boiling impurities are removed by distillation under reduced pressure to obtain epoxy-modified polysiloxane.

[0014] Further, the modified reinforcing fiber is processed by the following steps:

[0015] A1. Add basalt short fibers and pretreatment solution into a reactor and stir. Raise the temperature of the reactor to 70-80°C, keep warm and stir for 40-60 minutes, and perform post-treatment to obtain pretreated fibers.

[0016] A2. Add the pretreated fiber and buffer solution into the reactor and stir. Raise the temperature of the reactor to 50-60°C. Add dopamine hydrochloride solution into the reactor and keep the temperature for 6-8h. Post-treat to obtain modified reinforced fiber.

[0017] The synthetic reaction mechanism of the modified reinforcing fiber is:

[0018] The sulfuric acid and hydrogen peroxide in the pretreatment solution work together to etch and oxidize the surface of the basalt staple fibers, introduce functional groups such as carboxyl and hydroxyl groups into the basalt staple fibers, and increase the activity of the fiber surface. In a buffer environment, by optimizing the composition of the buffer and promoting the uniform dispersion of the pretreated fibers in the buffer, the dopamine molecules react with the functional groups on the fiber surface through the amino and phenolic hydroxyl groups. At the same time, self-polymerization occurs between the dopamine molecules, forming a dense polydopamine layer on the outside of the basalt staple fibers to prepare modified reinforced fibers.

[0019] Furthermore, in step A1, the dosage ratio of the basalt staple fiber and the pretreatment solution is 1g:20mL, the pretreatment solution is composed of 20-30wt% sulfuric acid and hydrogen peroxide in a volume ratio of 5:1, and the post-treatment includes: after the reaction is completed, the temperature of the reactor is lowered to room temperature, filtered, the filter cake is washed with purified water until neutral and then dried, the filter cake is transferred to a drying oven at a temperature of 70-80°C, and dried to constant weight to obtain pretreated fiber; in step A2, the dosage ratio of the pretreated fiber, buffer solution and dopamine hydrochloride solution is 3g:100mL:50mL, and the buffer solution is 0.01mol / L containing sodium dodecyl sulfate with a pH of 8. The Tris-HCl aqueous solution has a concentration of 2-3 g / L of dopamine hydrochloride solution. The post-treatment comprises: after the reaction is completed, the temperature of the reactor is lowered to room temperature, the filter cake is filtered, the filter cake is washed with purified water until it is neutral and then dried, the filter cake is transferred to a drying oven at a temperature of 70-80°C, and vacuum dried to constant weight to obtain modified reinforced fibers.

[0020] Furthermore, the preparation method of the reinforced elastomer is: add modified silicone oil, 1-octadecene, butyl acrylate, and toluene into a reactor and stir, increase the temperature of the reactor to 80-90°C, add an initiator into the reactor, keep the reaction warm for 6-8 hours, and post-treat to obtain the reinforced elastomer.

[0021] The synthetic reaction formula of the reinforced elastomer is:

[0022]

[0023] Where:

[0024] The synthetic reaction mechanism of reinforced elastomer is:

[0025] Under the action of free radical initiator, the olefin double bonds on the modified silicone oil, 1-octadecene and butyl acrylate molecules are broken and then undergo free radical condensation reaction to form long alkane straight chains modified with polyalkane branches, and the polysiloxane chain is used to promote the cross-linking and winding of the polylong alkane branches to form a reinforced elastomer.

[0026] Furthermore, the amount ratio of the modified silicone oil, 1-octadecene, butyl acrylate, toluene and initiator is 2g:2g:5g:50mL:0.05g, the initiator is azobisisobutyronitrile, and the post-treatment includes: after the reaction is completed, the temperature of the reactor is kept at 80-90°C, and the solvent is evaporated under reduced pressure to obtain a reinforced elastomer.

[0027] Furthermore, the preparation method of the modified silicone oil is: octamethylcyclotetrasiloxane, aminopropylmethyldiethoxysilane, tetramethyldivinyldisiloxane and a catalyst are added to a reaction kettle and stirred, the temperature of the reaction kettle is increased to 80-90°C, the reaction is kept warm for 5-7h, and the modified silicone oil is obtained by post-treatment.

[0028] The synthetic reaction formula of modified silicone oil is:

[0029]

[0030] The synthetic reaction mechanism of modified silicone oil is:

[0031] Under the catalysis of sulfuric acid, the ethoxy group of ethoxysilane, octamethylcyclotetrasiloxane and the hydroxyl group on tetramethyldivinyldisiloxane undergo a dehydration condensation reaction to form a new silicon-oxygen-silicon bond, thereby obtaining a long siloxane chain segment. The tetramethyldivinyldisiloxane molecule is hydrolyzed under the action of the catalyst to produce terminal olefin dimethylsilanol, which is modified at the end of the polysiloxane molecular chain as a capping agent to form an olefin capping modification on the polysiloxane molecular chain.

[0032] Furthermore, the amount ratio of octamethylcyclotetrasiloxane, aminopropylmethyldiethoxysilane, tetramethyldivinyldisiloxane and catalyst is 25g:5g:1g:1g, the catalyst is 10-20wt% sulfuric acid, and the post-treatment includes: after the reaction is completed, the temperature of the reactor is reduced to room temperature, purified water and toluene are added to the reactor, stirred for 30-40min, allowed to stand for separation, the organic phase is washed with purified water to neutrality, the organic phase is transferred to the reactor, the temperature of the reactor is increased to 90-100°C, and low-boiling impurities are removed by reduced pressure to obtain modified silicone oil.

[0033] The present invention also proposes a method for preparing a rutting-resistant enhanced epoxy asphalt mixture. The method for preparing the rutting-resistant enhanced epoxy asphalt mixture is as follows: adding base asphalt and additive additives into a nitrogen-protected reactor for mixing, raising the temperature of the reactor to 180-200°C, heating until the base asphalt is melted, adding reinforcing elastomer, epoxy-modified polysiloxane and modified reinforcing fiber to the reactor in sequence, keeping warm and mixing for 20-30 minutes, adding aggregates to the reactor in batches, mixing for 40-50 minutes after the addition is completed, discharging the materials, and obtaining the epoxy asphalt mixture.

[0034] Furthermore, the grade of the matrix asphalt is any one of 70#, 90#, 110#, 120#, and 150#, the aggregate is composed of coarse aggregate and fine aggregate in a weight ratio of 3:1, the coarse aggregate and fine aggregate are both composed of gravel, the particle size of the coarse aggregate is 2-3cm, and the particle size of the fine aggregate is 2-5mm, the additives are composed of plasticizer, stabilizer, antioxidant, and adhesive in a weight ratio of 3:1:1:4, the plasticizer is styrene-propylene-butadiene copolymer, the stabilizer is polyacrylamide, the antioxidant is any one of antioxidant 1010 and antioxidant 2246, and the adhesive is styrene-butadiene emulsion.

[0035] The present invention has the following beneficial effects:

[0036] 1. The rutting-resistant reinforced epoxy asphalt mixture of the present application is reinforced by reinforcing the asphalt mixture composed of base asphalt and aggregate with reinforcing elastomer, epoxy-modified polysiloxane and modified reinforcing fiber. Under high temperature, the ring-opening condensation between epoxy groups and active groups such as amino groups and imino groups is promoted, so that the intermolecular crosslinking degree of the epoxy asphalt mixture is enhanced. The molecular composition structure of the reinforcing elastomer, epoxy-modified polysiloxane and modified reinforcing fiber is optimized, and the synergistic effect formed between the multiple components is utilized to improve the rutting resistance, water stability and low temperature resistance of the epoxy asphalt mixture.

[0037] 2. The rutting-resistant enhanced epoxy asphalt mixture of the present application is formed by free radical condensation reaction of modified silicone oil, 1-octadecene, butyl acrylate, etc., and has a long alkane straight chain structure modified with multiple alkane branches, and a reinforced elastomer that promotes the cross-linking and winding of multiple long alkane branches with polysiloxane chains. This structure enables the reinforced elastomer to have excellent elasticity, toughness and weather resistance. The addition of the reinforced elastomer gives the asphalt mixture better deformation recovery ability, improves the elastic modulus of the epoxy asphalt mixture, thereby reducing its permanent deformation during the stress process and improving the rutting resistance of the epoxy asphalt mixture. In addition, the amino group modified by the polysiloxane molecular chain can form a cross-linking bond with the epoxy group in the epoxy asphalt under high temperature environment, change the internal structure of the epoxy asphalt mixture, make it more compact and stable, and further improve the rutting resistance of the epoxy asphalt mixture. At the same time, the excellent water resistance, elasticity and toughness of the enhanced elastomer help reduce the erosion of moisture on the epoxy asphalt mixture, thereby reducing the negative effects of moisture and low temperature on the performance of the mixture, and improving the water stability and low temperature resistance of the asphalt mixture.

[0038] 3. The rutting-resistant reinforced epoxy asphalt mixture of the present application is prepared by pre-treating basalt short fibers and then dispersing and modifying them with dopamine hydrochloride, and modifying the basalt short fibers with functional groups such as hydroxyl, carboxyl, amino and imino groups on the outside, thereby enhancing the interaction between the basalt short fibers and the epoxy asphalt matrix, and improving the dispersion and stability of the fibers in the mixture. In addition, the presence of the polydopamine layer can effectively prevent moisture from penetrating into the interface between the fibers and the matrix, and reduce the interface damage caused by moisture erosion. The active functional groups modified on the surface of the modified reinforced fibers can enhance the bonding strength between the fibers and the matrix, and then cooperate with the reinforced elastomer. , further improving the freeze-thaw resistance of asphalt mixture; the epoxy-modified polysiloxane of the present invention combines the rigidity of epoxy resin and the flexibility of polysiloxane, and the silanol and epoxy groups in the epoxy-modified polysiloxane molecular chain can chemically react with the active components in asphalt to form chemical bonds, thereby improving the water stability of the asphalt mixture and reducing the negative impact of moisture on the performance of the mixture. The polysiloxane segment has excellent water resistance, toughness and low-temperature resistance, and can maintain good elasticity under low temperature conditions, thereby cooperating with the reinforcing elastomer and the modified reinforcing fiber to improve the anti-rutting performance of the asphalt mixture and its anti-cracking performance and water stability under low temperature conditions. DETAILED DESCRIPTION

[0039] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In the present application, the styrene content in the styrene-propylene-butadiene copolymer is 45-55%; the molecular weight of the polyacrylamide is 15-20 million; the solid content of the styrene-butadiene emulsion is 50.0%, the viscosity is 600 mPa·s, and the particle size is 135 nm; the diameter of the basalt short fiber is 1-25 μm, the length is 3-6 mm, and the density is 2.6-2.8 g / m 3 .

[0041] Example 1

[0042] This embodiment provides a method for preparing an anti-rutting enhanced epoxy asphalt mixture, comprising the following steps:

[0043] S1. Preparation of reinforced elastomer

[0044] Weigh: 500g of octamethylcyclotetrasiloxane, 100g of aminopropylmethyldiethoxysilane, 20g of tetramethyldivinyldisiloxane and 20g of 10wt% sulfuric acid, add them into a reactor and stir, raise the temperature of the reactor to 80°C, keep the reaction for 5h, after the reaction is completed, lower the temperature of the reactor to room temperature, add 1000mL of purified water and 2000mL of toluene into the reactor, stir for 30min, stand and separate, wash the organic phase with purified water until neutral, transfer the organic phase to the reactor, raise the temperature of the reactor to 90°C, and remove low-boiling impurities under reduced pressure to obtain modified silicone oil;

[0045] Weigh: 200 g of modified silicone oil, 200 g of 1-octadecene, 500 g of butyl acrylate, and 5000 mL of toluene, add into a reactor and stir, raise the temperature of the reactor to 80°C, add 5 g of azobisisobutyronitrile into the reactor, and keep the reaction for 6 hours. After the reaction is completed, keep the temperature of the reactor at 80°C, and evaporate the solvent under reduced pressure to obtain a reinforced elastomer.

[0046] S2. Preparation of epoxy-modified polysiloxane

[0047] Weigh: 500g of 3-glycidyloxypropylmethyldiethoxysilane, 300g of diphenyldihydroxysilane, 200g of 3-glycidyloxypropylmethyltriethoxysilane and 100g of 8wt% sodium hydroxide solution, add them into a nitrogen-protected reactor and stir, the temperature of the reactor is raised to 75°C, and the reaction is kept warm for 6h. After the reaction is completed, the temperature of the reactor is lowered to room temperature, 3L of purified water is added to the reactor, stirred for 10min, and the aqueous phase is separated by standing. The organic layer is washed with purified water until neutral and then transferred to the reactor. The temperature of the reactor is raised to 80°C, and low-boiling impurities are removed by distillation under reduced pressure to obtain epoxy-modified polysiloxane.

[0048] S3, modified reinforcing fiber

[0049] 20 wt % sulfuric acid and 25 wt % hydrogen peroxide were mixed uniformly in a volume ratio of 5:1 to obtain a pretreatment solution;

[0050] Basalt short fibers and pretreatment solution were added to a reactor at a ratio of 1 g:20 mL and stirred. The reactor temperature was raised to 70°C and stirred for 40 minutes. After the reaction was completed, the reactor temperature was lowered to room temperature and filtered. The filter cake was washed with purified water until neutral and then dried. The filter cake was transferred to a drying oven at 70°C and dried to constant weight to obtain pretreated fibers.

[0051] 0.01 mol / L Tris-HCl aqueous solution and sodium dodecyl sulfate were mixed uniformly at a ratio of 100 mL:1 g, and the pH of the mixed solution was adjusted to 8 to obtain a buffer solution;

[0052] Weigh: 300 g of pretreated fiber and 10,000 mL of buffer solution are added to the reactor and stirred. The temperature of the reactor is raised to 50°C. 500 mL of 2 g / L dopamine hydrochloride aqueous solution is added to the reactor and the reaction is kept warm for 6 hours. After the reaction is completed, the temperature of the reactor is lowered to room temperature, filtered, the filter cake is washed with purified water until it is neutral and then dried. The filter cake is transferred to a drying oven at a temperature of 70°C and vacuum dried to constant weight to obtain modified reinforced fiber.

[0053] S4. Preparation of epoxy asphalt mixture

[0054] Gravel with a particle size of 2-3 cm and gravel powder with a particle size of 2-5 mm as fine aggregate are mixed evenly in a weight ratio of 3:1 to obtain aggregate;

[0055] Select 70# asphalt as the base asphalt;

[0056] The styrene-propylene-butadiene copolymer, polyacrylamide, antioxidant 1010 and styrene-butadiene emulsion are uniformly mixed in a weight ratio of 3:1:1:4 to obtain an additive;

[0057] Weigh by weight: 16 parts of base asphalt and 0.8 parts of additives are added to a nitrogen-protected reactor and mixed. The temperature of the reactor is raised to 180°C and heated until the base asphalt is melted. 4 parts of reinforcing elastomer, 3 parts of epoxy-modified polysiloxane and 4 parts of modified reinforcing fiber are added to the reactor in sequence. Keep warm and mix for 20 minutes. Add 65 parts of aggregate to the reactor in batches. After the addition is completed, mix for 40 minutes and discharge the material to obtain epoxy asphalt mixture.

[0058] Example 2

[0059] This embodiment provides a method for preparing an anti-rutting enhanced epoxy asphalt mixture, comprising the following steps:

[0060] S1. Preparation of reinforced elastomer

[0061] Weigh: 500g of octamethylcyclotetrasiloxane, 100g of aminopropylmethyldiethoxysilane, 20g of tetramethyldivinyldisiloxane and 20g of 15wt% sulfuric acid, add them into a reactor and stir, raise the temperature of the reactor to 85°C, keep the reaction for 6h, after the reaction is completed, lower the temperature of the reactor to room temperature, add 1000mL of purified water and 2000mL of toluene into the reactor, stir for 35min, stand for separation, wash the organic phase with purified water until neutral, transfer the organic phase to the reactor, raise the temperature of the reactor to 95°C, remove low-boiling impurities under reduced pressure, and obtain modified silicone oil;

[0062] Weigh: 200 g of modified silicone oil, 200 g of 1-octadecene, 500 g of butyl acrylate, and 5000 mL of toluene, add into a reactor and stir, raise the temperature of the reactor to 85°C, add 5 g of azobisisobutyronitrile into the reactor, and keep the temperature for 7 hours. After the reaction is completed, keep the temperature of the reactor at 85°C, and evaporate the solvent under reduced pressure to obtain a reinforced elastomer.

[0063] S2. Preparation of epoxy-modified polysiloxane

[0064] Weigh: 600g of 3-glycidyloxypropylmethyldiethoxysilane, 400g of diphenyldihydroxysilane, 250g of 3-glycidyloxypropylmethyltriethoxysilane and 100g of 10wt% sodium hydroxide solution, add them into a nitrogen-protected reactor and stir, the temperature of the reactor is raised to 80°C, and the reaction is kept warm for 7h. After the reaction is completed, the temperature of the reactor is lowered to room temperature, 3L of purified water is added to the reactor, stirred for 13min, and allowed to stand to separate the water phase. The organic layer is washed with purified water until neutral and then transferred to the reactor. The temperature of the reactor is raised to 85°C, and low-boiling impurities are removed under reduced pressure to obtain epoxy-modified polysiloxane.

[0065] S3, modified reinforcing fiber

[0066] 25 wt % sulfuric acid and 27 wt % hydrogen peroxide were mixed uniformly in a volume ratio of 5:1 to obtain a pretreatment solution;

[0067] Basalt short fibers and pretreatment solution were added to a reactor at a ratio of 1 g: 20 mL and stirred. The reactor temperature was raised to 75°C and stirred for 50 minutes. After the reaction was completed, the reactor temperature was lowered to room temperature and filtered. The filter cake was washed with purified water until neutral and then dried. The filter cake was transferred to a drying oven at 75°C and dried to constant weight to obtain pretreated fibers.

[0068] 0.01 mol / L Tris-HCl aqueous solution and sodium dodecyl sulfate were mixed evenly at a ratio of 100 mL:1 g, and the pH of the mixed solution was adjusted to 8 to obtain a buffer solution;

[0069] Weigh: 300 g of pretreated fiber and 10,000 mL of buffer solution are added to the reactor and stirred. The temperature of the reactor is raised to 55°C. 500 mL of 2.5 g / L dopamine hydrochloride aqueous solution is added to the reactor and the reaction is kept warm for 7 hours. After the reaction is completed, the temperature of the reactor is lowered to room temperature, filtered, the filter cake is washed with purified water until it is neutral and then dried. The filter cake is transferred to a drying oven at a temperature of 75°C and vacuum dried to constant weight to obtain modified reinforced fiber.

[0070] S4. Preparation of epoxy asphalt mixture

[0071] Gravel with a particle size of 2-3 cm and gravel powder with a particle size of 2-5 mm as fine aggregate are mixed evenly in a weight ratio of 3:1 to obtain aggregate;

[0072] Select the asphalt with the grade of 110# as the base asphalt;

[0073] The styrene-propylene-butadiene copolymer, polyacrylamide, antioxidant 2246, and styrene-butadiene emulsion are uniformly mixed in a weight ratio of 3:1:1:4 to obtain an additive;

[0074] Weigh by weight: 18 parts of base asphalt and 0.9 parts of additives are added to a nitrogen-protected reactor and mixed. The temperature of the reactor is raised to 190°C and heated until the base asphalt is melted. 5 parts of reinforcing elastomer, 4 parts of epoxy-modified polysiloxane and 4.5 parts of modified reinforcing fiber are added to the reactor in sequence. Keep warm and mix for 25 minutes. Add 70 parts of aggregate to the reactor in batches. After the addition is completed, mix for 45 minutes and discharge the material to obtain epoxy asphalt mixture.

[0075] Example 3

[0076] This embodiment provides a method for preparing an anti-rutting enhanced epoxy asphalt mixture, comprising the following steps:

[0077] S1. Preparation of reinforced elastomer

[0078] Weigh: 500g of octamethylcyclotetrasiloxane, 100g of aminopropylmethyldiethoxysilane, 20g of tetramethyldivinyldisiloxane and 20g of 20wt% sulfuric acid, add them into a reactor and stir, raise the temperature of the reactor to 90°C, keep the reaction for 7h, after the reaction is completed, lower the temperature of the reactor to room temperature, add 1000mL of purified water and 2000mL of toluene into the reactor, stir for 40min, stand for separation, wash the organic phase with purified water until neutral, transfer the organic phase to the reactor, raise the temperature of the reactor to 100°C, remove low-boiling impurities under reduced pressure, and obtain modified silicone oil;

[0079] Weigh: 200 g of modified silicone oil, 200 g of 1-octadecene, 500 g of butyl acrylate, and 5000 mL of toluene, add into a reactor and stir, raise the temperature of the reactor to 90°C, add 5 g of azobisisobutyronitrile into the reactor, and keep the temperature for 8 hours. After the reaction is completed, keep the temperature of the reactor at 90°C, and evaporate the solvent under reduced pressure to obtain a reinforced elastomer.

[0080] S2. Preparation of epoxy-modified polysiloxane

[0081] Weigh: 700g of 3-glycidyloxypropylmethyldiethoxysilane, 500g of diphenyldihydroxysilane, 300g of 3-glycidyloxypropylmethyltriethoxysilane and 100g of 12wt% sodium hydroxide solution, add them into a nitrogen-protected reactor and stir, the temperature of the reactor is raised to 85°C, and the reaction is kept warm for 8h. After the reaction is completed, the temperature of the reactor is lowered to room temperature, 3L of purified water is added to the reactor, stirred for 15min, and the aqueous phase is separated by standing. The organic layer is washed with purified water until neutral and then transferred to the reactor. The temperature of the reactor is raised to 90°C, and low-boiling impurities are removed by distillation under reduced pressure to obtain epoxy-modified polysiloxane.

[0082] S3, modified reinforcing fiber

[0083] 30 wt % sulfuric acid and 29 wt % hydrogen peroxide were mixed uniformly in a volume ratio of 5:1 to obtain a pretreatment solution;

[0084] Basalt short fibers and pretreatment solution were added to a reactor at a ratio of 1 g: 20 mL and stirred. The temperature of the reactor was raised to 80°C and stirred for 60 minutes. After the reaction was completed, the temperature of the reactor was lowered to room temperature and filtered. The filter cake was washed with purified water until neutral and then dried. The filter cake was transferred to a drying oven at 80°C and dried to constant weight to obtain pretreated fibers.

[0085] 0.01 mol / L Tris-HCl aqueous solution and sodium dodecyl sulfate were mixed uniformly at a ratio of 100 mL:1 g, and the pH of the mixed solution was adjusted to 8 to obtain a buffer solution;

[0086] Weigh: 300 g of pretreated fiber and 10,000 mL of buffer solution are added to the reactor and stirred. The temperature of the reactor is raised to 60°C. 500 mL of 3 g / L dopamine hydrochloride aqueous solution is added to the reactor and the reaction is kept warm for 8 hours. After the reaction is completed, the temperature of the reactor is lowered to room temperature, filtered, the filter cake is washed with purified water until it is neutral and then dried. The filter cake is transferred to a drying oven at 80°C and vacuum dried to constant weight to obtain modified reinforced fiber.

[0087] S4. Preparation of epoxy asphalt mixture

[0088] Gravel with a particle size of 2-3 cm and gravel powder with a particle size of 2-5 mm as fine aggregate are mixed evenly in a weight ratio of 3:1 to obtain aggregate;

[0089] Select 150# asphalt as the base asphalt;

[0090] The styrene-propylene-butadiene copolymer, polyacrylamide, antioxidant 1010 and styrene-butadiene emulsion are uniformly mixed in a weight ratio of 3:1:1:4 to obtain an additive;

[0091] Weigh by weight: 20 parts of base asphalt and 1 part of additive, add to a nitrogen-protected reactor and mix, raise the temperature of the reactor to 200°C, heat until the base asphalt is melted, add 6 parts of reinforcing elastomer, 5 parts of epoxy-modified polysiloxane and 5 parts of modified reinforcing fiber to the reactor in sequence, keep warm and mix for 30 minutes, add 75 parts of aggregate to the reactor in batches, mix for 50 minutes, discharge the material, and obtain epoxy asphalt mixture.

[0092] Comparative Example 1

[0093] The difference between this comparative example and Example 3 is that in step S1, 3-aminopropylene is used instead of modified silicone oil.

[0094] Comparative Example 2

[0095] The difference between this comparative example and Example 3 is that step S2 is eliminated, and the epoxy-modified polysiloxane in step S4 is replaced by commercially available bisphenol A epoxy resin E-51.

[0096] Comparative Example 3

[0097] The difference between this comparative example and Example 3 is that the modified reinforcing fiber in step S4 is replaced by the pretreated fiber in step S3.

[0098] Performance Test:

[0099] With reference to the standard GB / T 29050-2012 "Anti-rutting agent asphalt concrete for roads", the dynamic stability, residual stability of the water-immersed Marshall test, residual strength ratio of the freeze-thaw splitting test and low-temperature failure strain of the epoxy asphalt mixtures prepared in Examples 1-3 and Comparative Examples 1-3 are tested. The specific test results are shown in Table 1 below.

[0100] Table 1-Performance test data of the sample

[0101]

[0102]

[0103] Data Analysis:

[0104] A comparative analysis of the data in the above table shows that the dynamic stability of the epoxy asphalt mixture prepared by the present invention is 6911 times / mm, the residual stability of the immersion Marshall test reaches 93.2%, the residual strength ratio of the freeze-thaw splitting test reaches 87.2%, and the failure strain (-10°C, 50mm·min-1) reaches 4413με. All performance parameters are better than those of the comparative example, indicating that the present invention is to strengthen the asphalt mixture composed of matrix asphalt and aggregate with a reinforced elastomer cross-linked and wound with polysiloxane and long alkane branches, epoxy-modified polysiloxane combining the rigidity of epoxy resin and the flexibility of polysiloxane, and modified reinforcing fibers coated with polydopamine, which not only effectively improves the anti-rutting performance of the epoxy asphalt mixture, but also improves the water stability and low-temperature strength of the epoxy asphalt mixture.

[0105] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. An anti-rutting enhanced epoxy asphalt mixture, characterized in that: The invention comprises the following components by weight: 16-20 parts of base asphalt, 0.8-1 parts of additive, 4-6 parts of reinforcing elastomer, 3-5 parts of epoxy-modified polysiloxane, 4-5 parts of modified reinforcing fiber and 65-75 parts of aggregate; The preparation method of the epoxy-modified polysiloxane is as follows: 3-glycidyloxypropylmethyldiethoxysilane, diphenyldihydroxysilane, 3-glycidyloxypropylmethyltriethoxysilane and a catalyst are added into a nitrogen-protected reactor and stirred, the temperature of the reactor is increased to 75-85° C., the reaction is carried out by heat preservation for 6-8 hours, and post-treatment is performed to obtain the epoxy-modified polysiloxane.

2. The rutting-resistant enhanced epoxy asphalt mixture according to claim 1, characterized in that: The weight ratio of the 3-glycidyloxypropylmethyldiethoxysilane, diphenyldihydroxysilane, 3-glycidyloxypropylmethyltriethoxysilane and the catalyst is 5-7:3-5:2-3:1, and the catalyst is 8-12wt% sodium hydroxide solution.

3. The rutting-resistant enhanced epoxy asphalt mixture according to claim 1, characterized in that: The modified reinforcing fiber is processed by the following steps: A1. Add basalt short fibers and pretreatment solution into a reactor and stir. Raise the temperature of the reactor to 70-80°C, keep warm and stir for 40-60 minutes, and perform post-treatment to obtain pretreated fibers. A2. Add the pretreated fiber and buffer solution into the reactor and stir. Raise the temperature of the reactor to 50-60°C. Add dopamine hydrochloride solution into the reactor and keep the temperature for 6-8h. Post-treat to obtain modified reinforced fiber.

4. The rutting-resistant enhanced epoxy asphalt mixture according to claim 3, characterized in that: In step A1, the dosage ratio of the basalt staple fiber and the pretreatment solution is 1g:20mL, and the pretreatment solution is composed of 20-30wt% sulfuric acid and hydrogen peroxide in a volume ratio of 5:1; in step A2, the dosage ratio of the pretreatment fiber, the buffer solution and the dopamine hydrochloride solution is 3g:100mL:50mL, the buffer solution is a 0.01mol / L Tris-HCl aqueous solution with a pH of 8 containing sodium dodecyl sulfate, and the concentration of the dopamine hydrochloride solution is 2-3g / L.

5. The rutting-resistant enhanced epoxy asphalt mixture according to claim 1, characterized in that: The preparation method of the reinforced elastomer is as follows: adding modified silicone oil, 1-octadecene, butyl acrylate and toluene into a reactor and stirring, raising the temperature of the reactor to 80-90°C, adding an initiator into the reactor, keeping the temperature for 6-8h, and post-treating to obtain the reinforced elastomer.

6. The rutting-resistant enhanced epoxy asphalt mixture according to claim 5, characterized in that: The usage ratio of the modified silicone oil, 1-octadecene, butyl acrylate, toluene and initiator is 2g:2g:5g:50mL:0.05g, and the initiator is azobisisobutyronitrile.

7. The rutting-resistant enhanced epoxy asphalt mixture according to claim 5, characterized in that: The preparation method of the modified silicone oil is as follows: octamethylcyclotetrasiloxane, aminopropylmethyldiethoxysilane, tetramethyldivinyldisiloxane and a catalyst are added into a reaction kettle and stirred, the temperature of the reaction kettle is increased to 80-90° C., the reaction is kept warm for 5-7 hours, and the modified silicone oil is obtained by post-treatment.

8. The rutting-resistant enhanced epoxy asphalt mixture according to claim 7, characterized in that: The usage ratio of octamethylcyclotetrasiloxane, aminopropylmethyldiethoxysilane, tetramethyldivinyldisiloxane and catalyst is 25g:5g:1g:1g, and the catalyst is 10-20wt% sulfuric acid.

9. The method for preparing a rutting-resistant enhanced epoxy asphalt mixture according to any one of claims 1 to 8, characterized in that: The preparation method of the rutting-resistant enhanced epoxy asphalt mixture is as follows: adding base asphalt and additive additives into a nitrogen-protected reactor and mixing them, raising the temperature of the reactor to 180-200° C. and heating until the base asphalt is melted, adding reinforcing elastomer, epoxy-modified polysiloxane and modified reinforcing fiber into the reactor in sequence, keeping warm and mixing for 20-30 minutes, adding aggregates into the reactor in batches, mixing for 40-50 minutes after adding, discharging the materials, and obtaining the epoxy asphalt mixture.

10. The method for preparing a rutting-resistant enhanced epoxy asphalt mixture according to claim 9, characterized in that: The grade of the matrix asphalt is any one of 70#, 90#, 110#, 120#, and 150#, the aggregate is composed of coarse aggregate and fine aggregate in a weight ratio of 3:1, the coarse aggregate and fine aggregate are both composed of gravel, the particle size of the coarse aggregate is 2-3cm, and the particle size of the fine aggregate is 2-5mm, the additives are composed of plasticizer, stabilizer, antioxidant, and adhesive in a weight ratio of 3:1:1:4, the plasticizer is styrene-propylene-butadiene copolymer, the stabilizer is polyacrylamide, the antioxidant is any one of antioxidant 1010 and antioxidant 2246, and the adhesive is styrene-butadiene emulsion.

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