Molding agent for cold-mix asphalt mixture and preparation method thereof

Abstract

The invention discloses a modulus increasing agent for a cold-mixed asphalt mixture and a preparation method of the modulus increasing agent, and relates to the technical field of road engineering materials, the modulus increasing agent which is stable at high temperature, excellent in dynamic mechanical property and resistant to cracking at low temperature is prepared by optimizing components and a process; according to a modulus increasing agent premixing process, the asphalt is easier to disperse under a cold mixing condition, the dynamic modulus of a cold-mixed asphalt mixture is improved, meanwhile, relatively good low-temperature performance is kept, the compatibility of fibers and asphalt is improved through silane treatment, and after lignin fibers are oxidized and grafted, fumed silica is added to improve the dispersity and avoid fiber agglomeration; the SBS modifier and the tackifying resin cooperate to form an elastic network, so that the elasticity modulus of the asphalt is improved; the silane coupling agent reinforces interface bonding of the fiber and asphalt, and the plasticizer is added to counteract low-temperature brittleness of the resin, so that the asphalt modulus is improved, and water erosion is reduced. The modulus increasing agent for the cold-mixed asphalt mixture is particularly suitable for the technical field of road engineering materials, and has good popularization and application values.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road engineering materials, in particular to a modulus increasing agent for cold-mixed asphalt mixture and a preparation method thereof. BACKGROUND

[0002] With the increasing of highway transportation, especially the operation of high-grade highway channelized traffic, the advantages and defects of cold-mixed asphalt applied to road materials are more and more obvious. Cold-mixed asphalt mixture is widely used in road engineering due to its low construction temperature, low energy consumption, environmental protection and other advantages. However, compared with traditional hot-mixed asphalt mixture, the elastic modulus of cold-mixed asphalt mixture is lower, which leads to insufficient deformation resistance and durability, limits its application in heavy traffic roads, and shortens the service life of asphalt pavement. In order to improve the service quality and service life of asphalt materials on the road, an effective method is to improve the performance of asphalt mixture.

[0003] In the prior art, the methods for improving the modulus of asphalt mixture mainly include adding polymer modifiers, fiber reinforcing materials, etc., but these methods are mostly designed for hot-mixed asphalt mixture and are difficult to fully play a role under cold-mixed conditions. Especially under low-temperature mixing conditions, conventional modifiers are difficult to fully disperse and form an effective network structure with asphalt. In order to solve the above problems, the present application provides a modulus increasing agent for cold-mixed asphalt mixture and a preparation method thereof. The modulus increasing modifier can improve the modulus of asphalt mixture, reduce the deformation of asphalt mixture under the action of vehicle load, improve the deformation resistance of pavement, reduce the bending tensile stress of the bottom of asphalt surface layer, and prolong the service life of road. SUMMARY

[0004] The present application aims to provide a modulus increasing agent for cold-mixed asphalt mixture and a preparation method thereof to solve the problems in the prior art.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solutions: A preparation method of a modulus increasing agent for cold-mixed asphalt mixture, the steps of the preparation method are as follows: heating base asphalt to 150-160℃, adding SBS modifier, shearing at a shearing rate of 3000-4000r / min for 30-60min; cooling to 105-115℃, adding tackifying resin, shearing at 1500-2500r / min for 15-30min; cooling to 75-85℃, adding modulus increasing fiber, stirring at 1500-2000r / min for 5-10min; adding silane coupling agent, stabilizer and plasticizer, stirring for 40-50min, and keeping at 80-90℃ for 30-40min to obtain a modulus increasing agent for cold-mixed asphalt mixture; More preferably, the raw material composition of the matrix modifier is 45-55 parts of base pitch, 6-8 parts of SBS modifier, 8-10 parts of tackifying resin, 3-6 parts of matrix fiber, 2-5 parts of silane coupling agent, 1-3 parts of stabilizer, and 1-3 parts of plasticizer, by weight; More preferably, the tackifying resin is one of C5 petroleum resin, C9 petroleum resin, and terpene resin; the matrix fiber is one of polyester fiber and lignin fiber; the silane coupling agent is one of γ-aminopropyl triethoxysilane and γ-(2,3-epoxypropoxy) propyl trimethoxysilane; the stabilizer is one of sulfur and dicumyl peroxide; the plasticizer is phthalate plasticizer; and the length of the matrix fiber is 0.5-3 mm. More preferably, the lignin fiber is modified lignin fiber, and the preparation process of the modified lignin fiber is as follows: dispersing alkali lignin in deionized water, adjusting pH, increasing temperature, adding 30% H2O2 solution in mass concentration, reacting for 2-3 h, decreasing temperature, adding polyethyleneimine, stirring for 20-30 min, adding glue powder and fumed silica, and shearing for 30-40 min to obtain the modified lignin fiber. The raw material composition of the modified lignin fiber is 80-100 parts of alkali lignin, 450-500 parts of deionized water, 10-15 parts of H2O2 solution, 10-15 parts of polyethyleneimine, 5-10 parts of glue powder, and 0.2-0.3 parts of fumed silica. More preferably, the terpene resin is modified terpene resin, and the preparation process of the modified terpene resin is as follows: adding terpene resin and pretreated sodium borohydride into a reaction kettle, stirring at 0-5°C for 2-3 h, adjusting pH, adding 30% H2O2 solution in mass concentration, and incubating at 0-5°C for 50-60 min to obtain polyhydroxy terpene resin; adding acryloyl chloride, triethylamine, and tetrahydrofuran under nitrogen protection, and reacting at 0-5°C for 10-12 h to evaporate water, wash, and vacuum dry to obtain acrylate terpene resin; adding methyl methacrylate, initiator, anhydrous toluene, and vinyl-terminated polydimethylsiloxane, incubating at 60-70°C for 3-4 h, and distilling to obtain modified terpene resin; the pretreated sodium borohydride is obtained by pretreating sodium borohydride and tetrahydrofuran in a mass ratio of 1:10; The raw material composition of the modified terpene resin is 80-100 parts of terpene resin, 10-15 parts of pretreated sodium borohydride, 20-30 parts of H2O2 solution, 10-15 parts of acryloyl chloride, 15-20 parts of triethylamine, 40-50 parts of tetrahydrofuran, 15-20 parts of methyl methacrylate, 0.01-0.02 parts of azobisisobutyronitrile initiator, 100-120 parts of anhydrous toluene, and 10-12 parts of vinyl-terminated polydimethylsiloxane. More preferably, the plasticizer is a modified plasticizer, and the preparation process of the modified plasticizer is as follows: a palygorskite supported nickel catalyst is placed in a reaction kettle, pretreated in argon for 50-60 min, hydrogen is introduced, the temperature is raised to 280-300 DEG C, and reaction is carried out for 2-3 h, dioctyl phthalate is added, hydrogen is introduced at 110-120 DEG C, the temperature is raised to 150-160 DEG C, stirring is carried out for 3-4 h, filtration is carried out, and cooling to 55-60 DEG C is carried out, and the modified plasticizer is obtained by extraction separation. More preferably, the application of the plasticizer for cold asphalt mixture is as follows: the plasticizer is added to base asphalt at a proportion of 3-8% of the weight of the asphalt, and stirring is carried out at 50-60 DEG C for 5-10 min.

[0006] Compared with the prior art, the application has the following beneficial effects: The application provides a plasticizer for cold asphalt mixture and a preparation method thereof, and the plasticizer has high-temperature stability, excellent dynamic mechanical properties, and low-temperature crack resistance. Through specific formula design and preparation process, the raw materials can be well dispersed and start to play a role, the plasticizer premix makes it easier to disperse under cold mixing conditions, improves the dynamic modulus of cold asphalt mixture, and at the same time maintains good low-temperature performance, the compatibility of the fiber with asphalt is improved through silane treatment; the SBS modifier and tackifying resin cooperatively form an elastic network to improve the elastic modulus of asphalt; the silane coupling agent enhances the interfacial bonding between the fiber and asphalt, the modulus-increasing fiber forms a spatial support structure, and the product structure is stable; the stabilizer ensures the stability of the modified system at low temperature, improves the elastic recovery capacity and high-temperature stability of asphalt, and ensures uniform dispersion of the plasticizer. The modified lignin fiber is oxidized by H2O2 under alkaline conditions to generate carboxyl and aldehyde groups, the hydrophilicity is enhanced, then polyethyleneimine is grafted, and the acylation reaction between polyethyleneimine and lignin significantly improves the adsorption capacity of the fiber to the components of asphalt; after the oxidation and grafting of the lignin fiber, fumed silica is added to improve the dispersibility and avoid fiber agglomeration; the sulfur bond in the rubber powder crosslinks with the free radicals of lignin to improve the low-temperature toughness; the modified terpene resin is subjected to hydroboration-oxidative hydroxylation to increase the hydroxyl value of the resin, then reacts with acryloyl chloride to obtain acrylate terpene resin, provides free radical polymerization double bonds, enhances adhesion, and significantly improves the heat resistance and weather resistance; the modified plasticizer not only eliminates the toxicity of o-benzene to meet environmental protection requirements, but also significantly improves the thermal stability of the plasticizer; at the same time, the hydroxyl groups of the plasticizer condense with the silane of the modified terpene resin to improve the modulus of asphalt, the dynamic mechanical properties of the plasticizer are improved, the adhesion between the lignin fiber and asphalt is enhanced, and water erosion is reduced.

[0007] The cold-mixed asphalt mixture reinforcing agent of the application is particularly suitable for the technical field of road engineering materials, has high stability, excellent dynamic mechanical properties, good low-temperature crack resistance, good water stability, and meets the application requirements of road materials and the like, and has good popularization and application value. DETAILED DESCRIPTION

[0008] The technical solutions in the embodiments of the application will be clearly and completely described below. Obviously, the described embodiments are only some of the embodiments of the application, but not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0009] Embodiment 1: A preparation method of a cold-mixed asphalt mixture reinforcing agent, and the steps of the preparation method are as follows: heating base asphalt to 160 DEG C, adding 30-mesh SBS modifier, shearing at 3000 r / min for 60 min; cooling to 110 DEG C, adding tackifying resin, shearing at 1500 r / min for 20 min; cooling to 85 DEG C, adding lignin fiber, stirring at 1500 r / min for 10 min; adding silane coupling agent, stabilizer and plasticizer, stirring for 50 min, and keeping at 80 DEG C for 30 min to obtain a cold-mixed asphalt mixture reinforcing agent; The raw material composition of the reinforcing agent is 45 parts of base asphalt, 6 parts of SBS modifier, 10 parts of terpene resin, 6 parts of lignin fiber, 3 parts of gamma-aminopropyl triethoxysilane coupling agent, 2 parts of sulfur stabilizer and 2 parts of plasticizer, in terms of weight fraction; The lignin fiber is modified lignin fiber, and the preparation process of the modified lignin fiber is as follows: dispersing alkali lignin in deionized water, adjusting the pH to 11 with NaOH, heating to 70 DEG C, adding 30% H2O2 solution with a mass concentration, reacting for 2 h, cooling to 35 DEG C, adjusting the pH to 8, adding polyethyleneimine, stirring for 30 min, and shearing for 40 min to obtain modified lignin fiber after adding glue powder and fumed silica; The raw material composition of the modified lignin fiber is 100 parts of alkali lignin, 500 parts of deionized water, 15 parts of H2O2 solution, 15 parts of polyethyleneimine, 10 parts of glue powder and 0.3 parts of fumed silica; The terpene resin is a modified terpene resin, and the preparation process of the modified terpene resin is as follows: terpene resin and pretreated sodium borohydride are added into a reaction kettle, stirred at 0°C for 3h, the pH is adjusted to 11, a 30% H2O2 solution is added, and reaction is carried out at 5°C for 60 min to obtain a polyhydroxy terpene resin; under nitrogen protection, acryloyl chloride, triethylamine and tetrahydrofuran are added, and reaction is carried out at 0°C for 10h, and then water washing and vacuum drying are carried out to obtain an acrylate terpene resin; methyl methacrylate, an initiator, anhydrous toluene and vinyl-terminated polydimethylsiloxane are added, and incubation is carried out at 65°C for 4h, and then distillation is carried out to obtain the modified terpene resin; the pretreated sodium borohydride is obtained by pretreating 10g sodium borohydride with 100mL tetrahydrofuran; The raw material composition of the modified terpene resin comprises: 100 parts of terpene resin, 15 parts of pretreated sodium borohydride, 25 parts of H2O2 solution, 10 parts of acryloyl chloride, 20 parts of triethylamine, 50 parts of tetrahydrofuran, 20 parts of methyl methacrylate, 0.01 parts of azobisisobutyronitrile initiator, 10 parts of vinyl-terminated polydimethylsiloxane and 120 parts of anhydrous toluene; The plasticizer is a modified plasticizer, and the preparation process of the modified plasticizer is as follows: 3g attapulgite supported nickel catalyst is placed in a reaction kettle, pretreated in argon for 60 min, hydrogen is introduced, heated to 300°C, and reacted for 3h; 100g dioctyl phthalate is added, hydrogen is introduced at 120°C, heated to 160°C, stirred for 4h, filtered, cooled to 60°C, and then extracted and separated to obtain the modified plasticizer.

[0010] In example 2, a preparation method of a cold-mix asphalt mixture modifier is provided, and the steps of the preparation method are as follows: base asphalt is heated to 150°C, 30 mesh SBS modifier is added, and shearing is carried out at 4000r / min for 50 min; the temperature is lowered to 115°C, tackifying resin is added, and shearing is carried out at 2500r / min for 30 min; the temperature is lowered to 85°C, lignin fiber is added, and stirring is carried out at 2000r / min for 10 min; silane coupling agent, stabilizer and plasticizer are added, and stirring is carried out for 40 min; incubation is carried out at 90°C for 30 min to obtain a cold-mix asphalt mixture modifier. In example 2, a preparation method of a cold-mix asphalt mixture modifier is provided, and the steps of the preparation method are as follows: base asphalt is heated to 150°C, 30 mesh SBS modifier is added, and shearing is carried out at 4000r / min for 50 min; the temperature is lowered to 115°C, tackifying resin is added, and shearing is carried out at 2500r / min for 30 min; the temperature is lowered to 85°C, lignin fiber is added, and stirring is carried out at 2000r / min for 10 min; silane coupling agent, stabilizer and plasticizer are added, and stirring is carried out for 40 min; incubation is carried out at 90°C for 30 min to obtain a cold-mix asphalt mixture modifier. The lignin fiber is a modified lignin fiber, and the preparation process of the modified lignin fiber is as follows: alkali lignin is dispersed in deionized water, the pH is adjusted to 11 with NaOH, heated to 70°C, a 30% H2O2 solution is added, and reaction is carried out for 3h; the temperature is lowered to 45°C, the pH is adjusted to 8, polyethyleneimine is added, and stirring is carried out for 30 min; glue powder and fumed silica are added, and shearing is carried out for 40 min to obtain the modified lignin fiber. The raw material composition of the modified lignin fiber is: 80 parts of alkali lignin, 480 parts of deionized water, 15 parts of H2O2 solution, 10 parts of polyethyleneimine, 5 parts of glue powder, and 0.2 parts of fumed silica; The terpene resin is a modified terpene resin, and the preparation process of the modified terpene resin is as follows: terpene resin and pretreated sodium borohydride are added into a reaction kettle, stirred at 2℃ for 3h, the pH is adjusted to 11, 30% H2O2 solution is added, and the reaction is carried out at 5℃ for 60min to obtain a polyhydroxy terpene resin; acryloyl chloride, triethylamine and tetrahydrofuran are added under nitrogen protection, and the reaction is carried out at 5℃ for 12h; water washing and vacuum drying are carried out to obtain an acrylate terpene resin; methyl methacrylate, initiator, anhydrous toluene and vinyl-terminated polydimethylsiloxane are added, and the temperature is kept at 60℃ for 4h; and distillation is carried out to obtain the modified terpene resin; the pretreated sodium borohydride is obtained by pretreating 10g of sodium borohydride with 100mL of tetrahydrofuran; The raw material composition of the modified terpene resin is: 80 parts of terpene resin, 10 parts of pretreated sodium borohydride, 20 parts of H2O2 solution, 10 parts of acryloyl chloride, 15 parts of triethylamine, 50 parts of tetrahydrofuran, 20 parts of methyl methacrylate, 0.01 parts of azobisisobutyronitrile initiator, 10 parts of vinyl-terminated polydimethylsiloxane, and 100 parts of anhydrous toluene; The plasticizer is a modified plasticizer, and the preparation process of the modified plasticizer is as follows: 3g of attapulgite supported nickel catalyst is placed in a reaction kettle, pretreated in argon for 50min, hydrogen is introduced, the temperature is raised to 300℃, and the reaction is carried out for 3h; 100g of dioctyl phthalate is added, hydrogen is introduced at 120℃, the temperature is raised to 160℃, and stirring is carried out for 3h; filtration is carried out, and the temperature is cooled to 55℃; extraction separation is carried out to obtain the modified plasticizer.

[0011] Example 3: A preparation method of a modifier for cold asphalt mixture, and the steps of the preparation method are as follows: base asphalt is heated to 160℃, 30 mesh SBS modifier is added, and shearing is carried out at 3000r / min for 30min; the temperature is lowered to 110℃, tackifying resin is added, and shearing is carried out at 2000r / min for 25min; the temperature is lowered to 75℃, lignin fiber is added, and stirring is carried out at 1500r / min for 8min; silane coupling agent, stabilizer and plasticizer are added, and stirring is carried out for 40min; the temperature is kept at 85℃ for 30min to obtain a modifier for cold asphalt mixture; The raw material composition of the modifier is: 55 parts of base asphalt, 8 parts of SBS modifier, 8 parts of terpene resin, 6 parts of lignin fiber, 3 parts of γ-aminopropyl triethoxysilane coupling agent, 2 parts of sulfur stabilizer, and 2 parts of plasticizer, all in terms of weight fraction; The lignin fiber is modified lignin fiber, and a preparation process of the modified lignin fiber is as follows: alkali lignin is dispersed in deionized water, the pH is adjusted to 11, the temperature is increased to 70 DEG C, 30% H2O2 solution is added, reaction is carried out for 2 hours, the temperature is decreased to 40 DEG C, the pH is adjusted to 7, polyethyleneimine is added, stirring is carried out for 30 minutes, glue powder and fumed silica are added, and shearing is carried out for 30 minutes to obtain the modified lignin fiber. The raw material composition of the modified lignin fiber is as follows: 90 parts of alkali lignin, 500 parts of deionized water, 15 parts of H2O2 solution, 10 parts of polyethyleneimine, 8 parts of glue powder and 0.3 parts of fumed silica. The terpene resin is modified terpene resin, and a preparation process of the modified terpene resin is as follows: terpene resin and pretreated sodium borohydride are added into a reaction kettle, stirring is carried out at 2 DEG C for 3 hours, the pH is adjusted to 11, 30% H2O2 solution is added, reaction is carried out at 5 DEG C for 55 minutes to obtain polyhydroxy terpene resin; under nitrogen protection, acryloyl chloride, triethylamine and tetrahydrofuran are added, reaction is carried out at 2 DEG C for 11 hours, water washing and vacuum drying are carried out to obtain acrylate terpene resin; methyl methacrylate, initiator, anhydrous toluene and vinyl-terminated polydimethylsiloxane are added, 70 DEG C is kept for 3 hours, and distillation is carried out to obtain the modified terpene resin; the pretreated sodium borohydride is obtained by pretreating 10 g of sodium borohydride with 100 mL of tetrahydrofuran. The raw material composition of the modified terpene resin is as follows: 90 parts of terpene resin, 12 parts of pretreated sodium borohydride, 25 parts of H2O2 solution, 12 parts of acryloyl chloride, 18 parts of triethylamine, 45 parts of tetrahydrofuran, 15 parts of methyl methacrylate, 0.02 parts of azobisisobutyronitrile initiator, 11 parts of vinyl-terminated polydimethylsiloxane and 110 parts of anhydrous toluene. The plasticizer is modified plasticizer, and a preparation process of the modified plasticizer is as follows: 3 g of attapulgite supported nickel catalyst is placed in a reaction kettle, pretreatment is carried out in argon for 55 minutes, hydrogen is introduced, the temperature is increased to 290 DEG C, reaction is carried out for 3 hours, 100 g of dioctyl phthalate is added, hydrogen is introduced at 115 DEG C, the temperature is increased to 155 DEG C, stirring is carried out for 4 hours, filtration is carried out, and cooling is carried out to 60 DEG C to obtain the modified plasticizer.

[0012] Comparative Example 1: taking Example 1 as a control group, lignin fiber is used to replace modified lignin fiber, and other procedures are normal.

[0013] Comparative Example 2: taking Example 1 as a control group, terpene resin is used to replace modified terpene resin, and other procedures are normal.

[0014] The raw material sources (only as an exemplary example) are as follows: The raw materials in the technical scheme are products currently sold on the market. Base pitch (8052-42-4, industrial grade): China Petroleum Chemical Co., Ltd.; SBS modifier (9003-55-8, 99%): Balin Petroleum Chemical Co., Ltd.; γ-aminopropyl triethoxysilane coupling agent (919-30-2, 96%): Nanjing Shuguang Chemical Co., Ltd.; Sulfur (9035-99-8, 99%): Henan Kaiyun Chemical Co., Ltd.; Dioctyl phthalate plasticizer (117-84-0, 98%): Hubei Ximingtai Chemical Co., Ltd.; Lignin fiber (90%, 2mm): Zhenjiang Daoyi Material Technology Co., Ltd.; Polyethyleneimine (9002-98-6, 99%): Nantong Runfeng Petroleum Chemical Co., Ltd.; Fumed silica (112945-52-5, 99.8%): Hubei Huifunanomaterials Co., Ltd.; Rubber powder: Zhongjiao Resource Regeneration (Suzhou) Co., Ltd. sells products under the trade name of vulcanized rubber powder; Terpene resin (9003-74-1, 99%): Hubei Shishun Biological Technology Co., Ltd.; Sodium borohydride (16940-66-2, 98%): Hubei Xinrunde Chemical Co., Ltd.; Acryloyl chloride (814-68-6, 99%): Wuhan Shuiyixing Pharmaceutical Chemical Co., Ltd.; Methyl methacrylate (80-62-6, 99.9%): Shandong Jinyueyuan New Material Co., Ltd.; Azobisisobutyronitrile initiator (78-67-1, 99%): Shandong Yukang Chemical Co., Ltd.; Vinyl-terminated polydimethylsiloxane (68083-19-2, 99%): Hubei Qifei Pharmaceutical Chemical Co., Ltd.; Attapulgite supported nickel catalyst: Wuhan Kovater Chemical Co., Ltd. sells products under the product name KT-02 supported nickel catalyst; Triethylamine, acetic acid, NaOH, anhydrous ethanol, H2O2 solution, tetrahydrofuran, anhydrous toluene, analytical pure, commercially available.

[0015] Performance test: the cold-mix asphalt mixture prepared by the examples and comparative examples was tested with the modulus increasing agent: The modulus increasing agent and the base pitch were mixed at a mass ratio of 8:92, stirred at 60°C for 10 min, and then the sample was obtained after curing in a mold; (1) High temperature stability: a 300mm×300mm×50mm plate-shaped test piece was prepared by using an asphalt mixture rutting tester, and was placed in a 60°C constant temperature environment box for 6h. The test program was set as: the test wheel was rolled back and forth at a frequency of 42 times / min, and the test piece was rolled for 60 min, and the rut depth (RD) at 45 min and 60 min was recorded, and the dynamic stability DS=42×15 / (d 60 -d 45 ) times / mm was calculated.

[0016] (2) Water stability: using a universal material testing machine, equipped with an environmental chamber and a splitting clamp, prepare cylindrical samples with a size of diameter 100 mm x height 63.5 mm, divided into two groups: group A is stored at 25 DEG C; group B is vacuum saturated (vacuum degree 97.3 kPa, 15 min), -18 DEG C frozen for 16 h, 60 DEG C water bath for 24 h, and cycled twice. The test procedure is set as: splitting at a loading rate of 50 mm / min, calculating the freeze-thaw splitting strength ratio TSR = sigma t / sigma n x 100%, wherein sigma t is the strength of group B, and sigma n is the strength of group A.

[0017] (3) Dynamic mechanical property: using an asphalt mixture performance testing machine, dynamic modulus experiment is carried out, the sample is prepared into a cylindrical test piece with a diameter of 100 mm x height of 150 mm, and a contact load of 10 kPa is applied for pre-pressing. The test procedure is set as: uniaxial compression dynamic loading is carried out at a temperature point of 15 DEG C and a frequency of 10 Hz, the axial strain control is 100 mu epsilon, data is collected, and dynamic modulus |E*| = sigma o / epsilon o is calculated, wherein sigma o is stress amplitude, and epsilon o is strain amplitude.

[0018] (4) Low temperature crack resistance: using an electronic universal testing machine, equipped with a low temperature environmental chamber. Prepare a test sample with a size of 250 mm x 30 mm x 35 mm, and keep it at a constant temperature of -10 DEG C for 4 h. The test procedure is set as: three-point bending loading is carried out at a rate of 50 mm / min, the span is 200 mm, the data is recorded, and the breaking bending strain epsilon B = 6hd / L 2 is calculated, wherein h is the height of the cross-section test piece in the middle of the span, d is the breaking deflection, and L is the span.

[0019] (5) Fatigue resistance: using a hydraulic servo fatigue testing machine, a test piece with a size of 400 mm x 60 mm x 40 mm is prepared, and the temperature is controlled at 15 DEG C in a water bath for 2 h. The test procedure is set as: using load control mode, a sinusoidal wave load of 10 Hz is applied, the stiffness of the test piece is defined as 50% of the initial value when fatigue failure occurs, and the failure cycle number (Nf) is recorded.

[0020] The test results are as follows: Table 1

[0021] The analysis results are as follows: The application provides a cold-mixed asphalt mixture modulus increasing agent and a preparation method thereof.

[0022] Comparing example 1 with comparative example 1 and comparative example 2, it can be seen that, in order to improve the dynamic modulus of cold-mixed asphalt mixture while maintaining good low-temperature performance, SBS is selected to form a three-dimensional polymer network to improve the elastic recovery capacity, and the optimized modulus increasing agent significantly improves the high-temperature rutting resistance, and the dynamic stability is higher than 5000 times / mm. The silane coupling agent gamma-aminopropyl triethoxysilane strengthens the interface bonding between the fiber and the asphalt; the modified lignin fiber improves the dynamic modulus, the plasticizer relieves the brittleness caused by excessive crosslinking of SBS, improves the low-temperature ductility, has high modulus characteristics, the silane coupling agent reacts with the carboxyl group of the lignin fiber to form a chemical bond resistant to water erosion, has excellent water stability, and the freeze-thaw splitting strength ratio is greater than 85%; the polyethylene imine is grafted, the amine group of the polyethylene imine reacts with the carboxyl group of the lignin to form an amide, which significantly improves the adsorption capacity of the fiber to the asphalt components, the addition of fumed silica improves the dispersibility and avoids fiber agglomeration, the sulfur bond in the rubber powder crosslinks with the lignin free radicals to improve the low-temperature toughness; the modified terpene resin significantly improves the heat resistance and weather resistance of the modulus increasing agent; the modified plasticizer not only eliminates the toxicity of o-benzene to meet the environmental protection requirements, but also significantly improves the thermal stability of the modulus increasing agent; improves the modulus of asphalt, enhances the bonding between the lignin fiber and the asphalt, reduces the water erosion, improves the compatibility, and improves the dynamic mechanical properties.

[0023] It is apparent for those skilled in the art that the present application is not limited to the details of the above-described exemplary embodiments, but can be implemented in other concrete forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all aspects as illustrative and not restrictive, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended to encompass all changes falling within the meaning and range of equivalents of the elements of the claims.

Claims

1. A method for preparing a modularizing agent for cold mix asphalt mixtures, characterized in that, The preparation method comprises the following steps: heating the base asphalt, adding the SBS modifier, shearing for 30-60 min; cooling, adding the tackifying resin, shearing for 15-30 min; cooling, adding the reinforcing fiber, stirring for 5-10 min; adding the silane coupling agent, the stabilizer and the plasticizer, stirring for 30-40 min, and heat preservation to obtain the reinforcing agent for cold-mixing asphalt mixture.

2. A method of preparing a modular increasing agent for cold mix asphalt mixtures according to claim 1, characterized in that: The raw material composition of the reinforcing agent comprises, in parts by weight, 45-55 parts of base asphalt, 6-8 parts of SBS modifier, 8-10 parts of tackifying resin, 3-6 parts of reinforcing fiber, 2-5 parts of silane coupling agent, 1-3 parts of stabilizer and 1-3 parts of plasticizer.

3. A method of preparing a modular increasing agent for cold mix asphalt mixtures according to claim 1, characterized in that: The tackifying resin is one of C5 petroleum resin, C9 petroleum resin and terpene resin; the reinforcing fiber is one of polyester fiber and lignin fiber; and the length of the reinforcing fiber is 0.5-3 mm.

4. A method of preparing a modular increasing agent for cold mix asphalt mixtures according to claim 1, characterized in that: The silane coupling agent is one of gamma-aminopropyl triethoxysilane and gamma-(2,3-epoxypropoxy) propyl trimethoxysilane; the stabilizer is one of sulfur and dicumyl peroxide; and the plasticizer is phthalate plasticizer.

5. A method of preparing a modular increasing agent for cold mix asphalt mixtures according to claim 3, characterized in that: The lignin fiber is modified lignin fiber, and the preparation process of the modified lignin fiber comprises the following steps: dispersing alkali lignin in deionized water, adjusting pH, heating, adding H2O2 solution, reacting for 2-3 h, cooling, adding polyethyleneimine, stirring for 20-30 min, and adding glue powder and fumed silica, and shearing for 30-40 min to obtain the modified lignin fiber.

6. A method of preparing a modular increasing agent for cold mix asphalt mixtures according to claim 5, characterized in that: The raw material composition of the modified lignin fiber comprises 80-100 parts of alkali lignin, 450-500 parts of deionized water, 15-20 parts of H2O2 solution, 10-15 parts of polyethyleneimine, 5-10 parts of glue powder and 0.2-0.3 parts of fumed silica.

7. A method of preparing a modular increasing agent for cold mix asphalt mixtures according to claim 3, characterized in that: The terpene resin is modified terpene resin, and the preparation process of the modified terpene resin comprises the following steps: adding terpene resin and pretreated sodium borohydride into a reaction kettle, stirring for 2-3 h, adjusting pH, adding H2O2 solution, and reacting for 50-60 min to obtain a polyhydroxy terpene resin; under nitrogen protection, adding acryloyl chloride, triethylamine and tetrahydrofuran, heat preserving for 10-12 h, water washing, vacuum drying to obtain an acrylate terpene resin; adding methyl methacrylate, an initiator, anhydrous toluene and vinyl-terminated polydimethylsiloxane, heat preserving for 3-4 h, and distilling to obtain the modified terpene resin; the pretreated sodium borohydride is obtained by pretreating sodium borohydride and tetrahydrofuran in a mass ratio of 1:

10.

8. A method of preparing a modular increasing agent for cold mix asphalt mixtures according to claim 7, characterized in that: The raw material composition of the modified terpene resin comprises 80-100 parts of terpene resin, 10-15 parts of pretreated sodium borohydride, 20-30 parts of H2O2 solution, 10-15 parts of acryloyl chloride, 15-20 parts of triethylamine, 40-50 parts of tetrahydrofuran, 15-20 parts of methyl methacrylate, 0.01-0.02 parts of an initiator, 10-12 parts of vinyl-terminated polydimethylsiloxane and 100-120 parts of anhydrous toluene.

9. The method of claim 1, wherein the method is characterized by: The plasticizer is a modified plasticizer, and the preparation process of the modified plasticizer is as follows: a palygorskite supported nickel catalyst is placed in a reaction kettle, pretreated in argon for 50-60 min, hydrogen is introduced, and the reaction is carried out by heating for 2-3 h, dioctyl phthalate is added, hydrogen is introduced by cooling, and the reaction is carried out by heating and stirring for 3-4 h, then the product is filtered, cooled, and extracted and separated to obtain the modified plasticizer.

10. A modularizing agent for cold-mix asphalt mixtures, characterized by: The modified plasticizer is prepared according to the preparation method in any one of claims 1-9.

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