Asphalt pavement crack pouring material and preparation method thereof

Abstract

The invention relates to an asphalt pavement crack pouring material and a preparation method thereof, and relates to the technical field of asphalt, the asphalt pavement crack pouring material comprises the following components by mass: 40-50 parts of asphalt, 10-15 parts of rubber powder, 8-10 parts of an SBS modifier, 20-30 parts of self-healing microcapsules, 5-8 parts of dioctyl phthalate, 2-4 parts of polyethylene wax, 15-25 parts of a filler, and 0.5-1 part of an anti-aging agent; the filler comprises nano silicon dioxide. The preparation method comprises the following steps: heating the asphalt until the asphalt is completely molten, adding the rubber powder and the SBS modifier, heating and stirring, adding the dioctyl phthalate and the polyethylene wax, heating and stirring, adding the nano silicon dioxide and the anti-aging agent, heating and stirring, adding the self-healing microcapsules, heating and stirring, thereby obtaining the asphalt pavement crack pouring material. The asphalt pavement crack pouring material has the effect of improving the adhesion performance and durability of the asphalt pavement crack pouring material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of asphalt, in particular to a crack pouring material for asphalt pavement and a preparation method thereof. BACKGROUND

[0002] In the modern transportation system, asphalt pavement has become the main choice for road paving due to its short closed traffic time, high driving comfort, good wear resistance and slip resistance, etc., and occupies a high proportion in highway construction in various countries. However, the asphalt binder is sensitive to temperature changes. In a low temperature environment, the asphalt becomes brittle and hard, and the fracture toughness is greatly reduced, causing low-temperature brittle fracture, and then causing transverse temperature shrinkage cracks on the pavement. At the same time, under the combined action of environmental load and vehicle load, the micro cracks at the bottom of the asphalt surface layer will gradually converge, and eventually form a bottom-up reflection crack.

[0003] Once the surface cracks occur, rainwater will enter the pavement. Due to the weak peeling property of water, the aggregate is prone to peel off from the pavement structure; the continuous application of vehicle load will generate hydrodynamic pressure at the bottom of the surface layer, accelerating the peeling process of the aggregate. In this way, the crack rapidly expands, causing more serious diseases such as net cracking and cracking, and even causing large-area rupture and collapse of the pavement, which sharply reduces the road performance of the asphalt pavement and greatly shortens its service life. Therefore, it is very important to regularly maintain the asphalt pavement and timely and effectively treat the cracks in the early stage of crack formation to maintain the good performance of the pavement and prolong its service life.

[0004] At present, the commonly used crack pouring technology mainly includes pouring cracks after heating asphalt in situ and pouring cracks with emulsified asphalt. Although these two methods can treat cracks to some extent, the pure asphalt material has the problem of poor adhesion, which is difficult to stably bond with the broken surface, and is still prone to brittle fracture under low temperature conditions; although the emulsified asphalt can be poured into deeper areas, its adhesion to the aggregate is also significantly affected by temperature, which is prone to debonding at high temperature, and has poor fatigue performance, resulting in difficult to maintain the maintenance effect, and often requiring secondary maintenance in a short time, which undoubtedly causes waste of manpower, time and economic resources, and therefore needs to be improved. SUMMARY

[0005] In order to improve the repair performance of the crack pouring material, the present application provides a crack pouring material for asphalt pavement and a preparation method thereof.

[0006] The crack pouring material for asphalt pavement and the preparation method thereof provided by the present application adopt the following technical scheme: In a first aspect, the crack pouring material for asphalt pavement provided by the present application adopts the following technical scheme: A crack pouring material for asphalt pavement, the preparation raw materials include the following components in mass fraction: Asphalt 40-50 parts Rubber powder 10-15 parts SBS modifier 8-10 parts Self-healing microcapsule 20-30 parts Dioctyl phthalate 5-8 parts Polyethylene wax 2-4 parts Filler 15-25 parts Anti-aging agent 0.5-1 part The filler includes nano-silica; The self-healing microcapsule is prepared by the following steps: A core material including epoxy soybean oil and an alkyl phenol polyoxyethylene ether are added to water, dicyandiamide is added, and emulsification is performed by heating and stirring to obtain an emulsion; urea is mixed with formaldehyde, the pH is adjusted to be alkaline, and reaction is performed by heating and stirring to obtain a urea-formaldehyde resin prepolymer; the urea-formaldehyde resin prepolymer is added to the emulsion, the pH is adjusted to be acidic, and reaction is performed by heating and stirring; after the reaction is completed, the pH is adjusted to be neutral, and centrifugation, washing, and drying are performed to obtain the self-healing microcapsule.

[0007] The base asphalt provides basic adhesion, the SBS modifier forms a three-dimensional network to enhance elasticity, the rubber powder improves deformation adaptability, and they are collectively used to build a crack-resistant framework; the dioctyl phthalate optimizes low-temperature flexibility, the polyethylene wax balances high-temperature fluidity, the nano-silica filler strengthens interface mechanical occlusion and shear strength, the anti-aging agent inhibits environmental degradation, and maintains long-term performance stability; the self-healing microcapsule is used to give the crack pouring material an intelligent repair function; when a crack expands to cause the microcapsule to break, the core material is released and penetrates to a damaged interface, a bonding network is reconstructed by molecular diffusion and chemical crosslinking, gaps are filled, and structural continuity is restored; through the synergistic effect of active repair and passive strengthening, the limitations of passive repair of traditional materials are broken through, an active protection mechanism of sensing-response-healing is realized, crack recurrence risk is reduced, and pavement service life is prolonged.

[0008] Preferably, the core material further includes dicyclopentadiene.

[0009] When the microcapsule breaks, dicyclopentadiene undergoes ring-opening polymerization under the catalysis of a curing agent to form a rigid polydicyclopentadiene skeleton network, which provides high initial strength and excellent immediate sealing required for rapid filling of cracks; at the same time, the epoxy soybean oil is crosslinked to form a flexible epoxy network, which forms a rigid-flexible interpenetrating network structure with dicyclopentadiene, improves the compression strength, low-temperature toughness, and interface bonding ductility of the repair body, and effectively prevents secondary cracking; in addition, the hydrophobicity of dicyclopentadiene enhances the waterproof durability of the repair body, and in combination with the physical strengthening effect of the filler nano-silica, the material is suitable for long-term, high-strength pavement crack repair under heavy traffic conditions.

[0010] Preferably, the mass ratio of dicyclopentadiene and epoxidized soybean oil in the core material is (0.15-0.25):1.

[0011] The self-healing microcapsules prepared according to the mass ratio have good repairing effect and can improve the adhesion and durability of the crack pouring material.

[0012] Preferably, the filler further comprises ettringite.

[0013] The ettringite forms needle-like crystals during the hydration process, and the volume expansion generated by the growth can effectively offset the tensile stress caused by the temperature shrinkage or water evaporation of the asphalt matrix, prevent interfacial debonding and internal shrinkage cracks, and generate self-stress to enhance the crack resistance. The ettringite interweaves with the gel in the asphalt to form a network structure, blocks the pore channels, and improves the compressive strength of the crack pouring body, thereby enhancing the durability and anti-rutting deformation ability. The unreacted ettringite precursor can continue to hydrate when it comes into contact with water, and can independently fill the newly generated microcracks through the delayed ettringite formation mechanism, especially suitable for rainy season environment, and can achieve long-term self-healing. The hexagonal columnar crystal structure of ettringite can form geometric interlocking with nano-silicon dioxide, disperse the stress in multiple directions during crack propagation, and improve the crack resistance. Through the effects of flexible filling and rigid reinforcement, the ettringite, self-healing microcapsules and nano-silicon dioxide synergistically improve the adhesion and durability of the crack pouring material.

[0014] Preferably, the mass ratio of nano-silicon dioxide and ettringite in the filler is 1:(0.01-0.03).

[0015] The filler compounded according to the above mass ratio can effectively improve the adhesion and durability of the crack pouring material.

[0016] Preferably, the filler is prepared by the following steps: Mix the nano-silicon dioxide and γ-aminopropyltriethoxysilane into the solvent, adjust the pH to be acidic, heat and stir to react, and then centrifuge, wash and dry to obtain modified silicon dioxide. Mix the modified silicon dioxide and ettringite and ball mill to obtain the modified filler.

[0017] The silanol generated by the hydrolysis of silane condenses with the hydroxyl groups on the surface of nano-silicon dioxide to form a silicon-oxygen bond, and the terminal amino group ionically bonds with the carboxyl group of asphalt to construct a filler-asphalt double chemical anchoring interface and improve the adhesion. Ball milling can optimize the microstructure of ettringite and modified silicon dioxide, improve their dispersibility and compatibility, thereby improving their synergistic effect, reducing stress concentration defects, and improving the durability of the crack pouring material.

[0018] Preferably, the preparation raw material further comprises maleic anhydride grafted SBS.

[0019] The maleic anhydride grafted SBS strengthens the interface bonding by polar anchoring, the maleic anhydride groups on the molecular chain of the maleic anhydride grafted SBS form strong hydrogen bonds or ionic bonds with the carboxyl and hydroxyl groups of the old asphalt pavement, and at the same time, the maleic anhydride groups on the molecular chain of the maleic anhydride grafted SBS interact with the surface of the filler, thereby enhancing the compatibility and bonding force between the SBS modifier, nano-silica and asphalt, forming a more stable network structure, and improving the durability of the crack pouring material; the maleic anhydride grafted SBS can improve the interface bonding between the self-healing microcapsules and the asphalt matrix, so that the microcapsules are more easily broken to release the repair components when cracks occur, thereby improving the self-healing efficiency and repair effect of the material, and prolonging the service life and service performance of the asphalt pavement crack pouring material.

[0020] Preferably, the amount of the maleic anhydride grafted SBS is 1-2 parts.

[0021] The addition of the maleic anhydride grafted SBS in the above-mentioned mass fraction can effectively improve the adhesion and durability of the crack pouring material.

[0022] Preferably, the anti-aging agent includes a benzotriazole ultraviolet absorber and a hindered amine light stabilizer.

[0023] In a second aspect, the present application provides an asphalt pavement crack pouring material and a preparation method thereof, which adopts the following technical scheme: A preparation method of an asphalt pavement crack pouring material, comprising the following steps: The asphalt is heated to complete melting, rubber powder and SBS modifier are added, after heating and stirring, dioctyl phthalate and polyethylene wax are added, after heating and stirring, nano-silica and an anti-aging agent are added, after heating and stirring, self-healing microcapsules are added, after heating and stirring, the asphalt pavement crack pouring material is obtained.

[0024] The crack pouring material prepared according to the above-mentioned steps has good adhesion, can effectively repair the cracks of the asphalt pavement, has good durability, and thus prolongs the service life and service performance of the asphalt pavement crack pouring material.

[0025] In summary, the present application has at least one of the following beneficial technical effects: 1. The base asphalt provides basic adhesion, the SBS modifier forms a three-dimensional network to enhance elasticity, and the rubber powder improves deformation adaptability, which together build a crack-resistant framework; the dioctyl phthalate optimizes low-temperature flexibility, the polyethylene wax balances high-temperature fluidity, the nano-silica filler strengthens the interface mechanical interlocking and shear strength, the anti-aging agent inhibits environmental degradation, and maintains long-term performance stability; the self-healing microcapsule gives the crack pouring material the intelligent repair function, when the crack expansion causes the microcapsule to break, the core material is released and penetrates to the damaged interface, and the bonding network is rebuilt through molecular diffusion and chemical crosslinking, filling the gap and restoring the structural continuity; through the synergistic effect of active repair and passive reinforcement, the passive repair limitations of traditional materials are broken through, an active protection mechanism of crack sensing-response-healing is realized, the risk of crack recurrence is reduced, and the service life of the pavement is prolonged.

[0026] 2. When the microcapsule breaks, dicyclopentadiene undergoes ring-opening polymerization under the catalysis of the curing agent to form a rigid polydicyclopentadiene skeleton network, providing high initial strength and excellent immediate sealing required for rapid filling of cracks; at the same time, the epoxy soybean oil crosslinks to form a flexible epoxy network, forming a rigid-flexible interpenetrating network structure with dicyclopentadiene, improving the compressive strength, low-temperature toughness and interface bonding ductility of the repair body, effectively preventing secondary cracking; in addition, the hydrophobicity of dicyclopentadiene enhances the water resistance durability of the repair body, and the physical reinforcement of the filler nano-silica makes the material suitable for long-term, high-strength pavement crack repair under heavy traffic conditions.

[0027] 3. Ettringite forms needle-like crystals during the hydration process, and the volume expansion generated by growth can effectively offset the tensile stress caused by temperature shrinkage or water evaporation in the asphalt matrix, preventing interface debonding and internal shrinkage cracks, and at the same time generating self-stress to enhance crack resistance, and interweaving with the gel in the asphalt to form a network structure, blocking pore channels, improving the compressive strength of the crack pouring body, and enhancing durability and anti-rutting deformation ability; unreacted ettringite precursors can continue to hydrate when exposed to water, autonomously filling new micro-cracks through a delayed ettringite formation mechanism, especially suitable for rainy season environments, achieving long-term self-healing; the hexagonal columnar crystal structure of ettringite can form a geometric interlock with nano-silica, dispersing stress in multiple directions during crack propagation, improving crack resistance, and through the effects of flexible filling and rigid reinforcement, ettringite, self-healing microcapsules and nano-silica synergistically improve the adhesion and durability of the crack pouring material. DETAILED DESCRIPTION

[0028] The application discloses a kind of asphalt pavement crack pouring material and preparation method thereof, raw materials used in the application can be obtained by commercially available raw materials except special instructions, the following will be further detailed in conjunction with example: Raw material description: alkylphenol polyoxyethylene ether (CAS No.: 9002-93-1), dicyandiamide (CAS No.: 461-58-5), epoxy soybean oil was purchased from Shandong Junfeng New Material Co., Ltd., urea (CAS No.: 57-13-6), formaldehyde (CAS No.: 50-00-0), citric acid (CAS No.: 77-92-9), 70# petroleum asphalt was purchased from Xingtai Dejia Road Material Sales Co., Ltd., rubber powder with the goods number of 2025 was purchased from Lingshou County Baixin New Material Technology Co., Ltd., Hainan Balin SBS792E was purchased from Changsha Shenli Chemical Technology Co., Ltd., dioctyl phthalate (CAS No.: 117-81-7), polyethylene wax with the type number of WAX2440 was purchased from Changzhou Kesaicheng Plastic Material Co., Ltd., nano-silicon dioxide with the type number of HB-151 was purchased from Hubei Hui Fu Nano Material Co., Ltd., UV-326 was purchased from Nanjing Milan New Material Co., Ltd., HALS-770 was purchased from Dongguan Baoshu Chemical Technology Co., Ltd., dicyclopentadiene (CAS: 77-73-6), calcium aluminate was purchased from Guangxi Xingao Building Material Co., Ltd., the particle size was 100 nm, and maleic anhydride grafted SBS with the goods number of HH0250UCIGT8 was purchased from Dongguan Shenghao Plastic Raw Material Co., Ltd.

[0029] Example 1 Preparation of self-healing microcapsules The core material includes epoxy soybean oil.

[0030] The core material and alkylphenol polyoxyethylene ether were added to water, dicyandiamide was added, and the mass ratio of the core material, alkylphenol polyoxyethylene ether, water and dicyandiamide was 18:4:77:1. Emulsification was carried out at 60°C at a speed of 8000 rpm for 30 min to obtain an emulsion; urea and formaldehyde were mixed in a molar ratio of 1:1.8, the pH was adjusted to 8.0 with 10% NaOH aqueous solution, and the reaction was carried out at 70°C with stirring at a speed of 200 rpm for 1 h to obtain a urea-formaldehyde resin prepolymer; the urea-formaldehyde resin prepolymer was added to the emulsion, and the mass ratio of the core material and the wall material was 1:1.3. The pH was adjusted to 4 with 10% citric acid aqueous solution, and the reaction was carried out at 65°C with stirring at a speed of 400 rpm for 2.5 h. After the reaction was completed, the pH was adjusted to neutral with 10% dilute ammonia water, and after centrifugal separation, it was washed with 40°C deionized water for 3 times, and then freeze-dried at -40°C to obtain self-healing microcapsules.

[0031] Preparation of asphalt pavement crack filling material Weigh 40 parts of asphalt, 10 parts of rubber powder, 8 parts of SBS modifier, 20 parts of self-healing microcapsule, 5 parts of dioctyl phthalate, 2 parts of polyethylene wax, 15 parts of filler, 0.5 parts of anti-aging agent; the asphalt is 70# petroleum asphalt, the rubber powder is 80 mesh, the SBS modifier is Hainan Balin SBS792E, the filler is nano silicon dioxide, and the anti-aging agent is composed of UV-326 and HALS-770 with a mass ratio of 1:1.

[0032] Heat the asphalt to complete melting, add the rubber powder and SBS modifier, stir at 170℃ with a speed of 600rpm for 1.5h, add the dioctyl phthalate and polyethylene wax, stir at 170℃ with a speed of 600rpm for 0.5h, add the nano silicon dioxide and anti-aging agent, stir at 130℃ with a speed of 400rpm for 0.5h, add the self-healing microcapsule, stir at 80℃ with a speed of 100rpm for 30min, to obtain the asphalt pavement crack pouring material.

[0033] Example 2 Preparation of self-healing microcapsule The core material includes epoxy soybean oil.

[0034] The core material and alkylphenol polyoxyethylene ether are added to water, dicyandiamide is added, the mass ratio of the core material, alkylphenol polyoxyethylene ether, water and dicyandiamide is 18:4:77:1, emulsified at 60℃ with a speed of 8000rpm for 30min to obtain an emulsion; urea and formaldehyde are mixed in a molar ratio of 1:1.8, the pH is adjusted to 8.0 with 10% NaOH aqueous solution, and the urea-formaldehyde resin prepolymer is obtained by stirring at 200rpm for 1h at 70℃; the urea-formaldehyde resin prepolymer is added to the emulsion, the mass ratio of the core material and wall material is 1:1.3, the pH is adjusted to 4 with 10% citric acid aqueous solution, and the reaction is carried out at 65℃ with a speed of 400rpm for 2.5h; after the reaction is completed, the pH is adjusted to neutral with 10% dilute ammonia water, centrifugal separation is carried out, and then the product is washed with 40℃ deionized water for 3 times, and then freeze-dried at-40℃ to obtain the self-healing microcapsule.

[0035] Preparation of asphalt pavement crack pouring material Weigh 40 parts of asphalt, 10 parts of rubber powder, 8 parts of SBS modifier, 20 parts of self-healing microcapsule, 5 parts of dioctyl phthalate, 2 parts of polyethylene wax, 15 parts of filler, 0.5 parts of anti-aging agent; the asphalt is 70# petroleum asphalt, the rubber powder is 80 mesh, the SBS modifier is Hainan Balin SBS792E, the filler is nano silicon dioxide, and the anti-aging agent is composed of UV-326 and HALS-770 with a mass ratio of 1:1.

[0036] The asphalt is heated to complete melting, the rubber powder and SBS modifier are added, stirring at 600 rpm for 1.5 h at 170℃, the dioctyl phthalate and polyethylene wax are added, stirring at 600 rpm for 0.5 h at 170℃, the nano-silica and anti-aging agent are added, stirring at 400 rpm for 0.5 h at 130℃, the self-healing microcapsules are added, stirring at 100 rpm for 30 min at 80℃, to obtain the asphalt pavement crack filling material.

[0037] Example 3 Preparation of self-healing microcapsules The core material includes epoxy soybean oil.

[0038] The core material and alkylphenol polyoxyethylene ether are added to water, dicyandiamide is added, the mass ratio of the core material, alkylphenol polyoxyethylene ether, water and dicyandiamide is 18:4:77:1, emulsification is carried out at 60℃ at a speed of 8000 rpm for 30 min to obtain an emulsion; urea and formaldehyde are mixed in a molar ratio of 1:1.8, the pH is adjusted to 8.0 with 10% NaOH aqueous solution, and the urea-formaldehyde resin prepolymer is obtained by stirring at 200 rpm for 1 h at 70℃; the urea-formaldehyde resin prepolymer is added to the emulsion, the mass ratio of the core material and the wall material is 1:1.3, the pH is adjusted to 4 with 10% citric acid aqueous solution, and the reaction is carried out at 65℃ at a speed of 400 rpm for 2.5 h; after the reaction is completed, the pH is adjusted to neutral with 10% dilute ammonia water, centrifugal separation is carried out, and then the product is washed with 40℃ deionized water for 3 times, and freeze-drying is carried out at -40℃ to obtain the self-healing microcapsules.

[0039] Preparation of asphalt pavement crack filling material 45 parts of asphalt, 12.5 parts of rubber powder, 9 parts of SBS modifier, 25 parts of self-healing microcapsules, 6.5 parts of dioctyl phthalate, 3 parts of polyethylene wax, 20 parts of filler, and 0.75 parts of anti-aging agent are weighed; the asphalt is 70# petroleum asphalt, the rubber powder is 80 mesh, the SBS modifier is Hainan Balin SBS792E, the filler is nano-silica, and the anti-aging agent is composed of UV-326 and HALS-770 in a mass ratio of 1:1.

[0040] The asphalt is heated to complete melting, the rubber powder and SBS modifier are added, stirring at 600 rpm for 1.5 h at 170℃, the dioctyl phthalate and polyethylene wax are added, stirring at 600 rpm for 0.5 h at 170℃, the nano-silica and anti-aging agent are added, stirring at 400 rpm for 0.5 h at 130℃, the self-healing microcapsules are added, stirring at 100 rpm for 30 min at 80℃, to obtain the asphalt pavement crack filling material.

[0041] Example 4 Example 4 is based on Example 3, the only difference between Example 4 and Example 3 is that the raw materials for preparing the self-healing microcapsules in Example 4 further include dicyclopentadiene, and the mass ratio of dicyclopentadiene to epoxidized soybean oil is 0.15:1.

[0042] Preparation of self-healing microcapsules The core material is composed of dicyclopentadiene and epoxidized soybean oil with a mass ratio of 0.15:1.

[0043] The core material and alkylphenol polyoxyethylene ether are added to water, dicyandiamide is added, and the mass ratio of the core material, alkylphenol polyoxyethylene ether, water, and dicyandiamide is 18:4:77:1. Emulsification is carried out at 60°C at a speed of 8000 rpm for 30 min to obtain an emulsion; urea and formaldehyde are mixed in a molar ratio of 1:1.8, the pH is adjusted to 8.0 with 10% NaOH aqueous solution, and the urea-formaldehyde resin prepolymer is obtained by stirring at 200 rpm for 1 h at 70°C; the urea-formaldehyde resin prepolymer is added to the emulsion, and the mass ratio of the core material to the wall material is 1:1.3. The pH is adjusted to 4 with 10% citric acid aqueous solution, and the reaction is carried out at 65°C with stirring at a speed of 400 rpm for 2.5 h. After the reaction is completed, the pH is adjusted to neutral with 10% dilute ammonia water, and after centrifugal separation, it is washed with 40°C deionized water for 3 times, and then freeze-dried at -40°C to obtain self-healing microcapsules.

[0044] Example 5 Example 5 is based on Example 4, the only difference between Example 5 and Example 4 is that the mass ratio of dicyclopentadiene to epoxidized soybean oil in Example 5 is 0.25:1.

[0045] Example 6 Example 6 is based on Example 4, the only difference between Example 6 and Example 4 is that the mass ratio of dicyclopentadiene to epoxidized soybean oil in Example 6 is 0.2:1.

[0046] Example 7 Example 7 is based on Example 4, the only difference between Example 7 and Example 4 is that the mass ratio of dicyclopentadiene to epoxidized soybean oil in Example 7 is 0.1:1.

[0047] Example 8 Example 8 is based on Example 4, the only difference between Example 8 and Example 4 is that the mass ratio of dicyclopentadiene to epoxidized soybean oil in Example 8 is 0.3:1.

[0048] Example 9 Example 9 is based on Example 3, the only difference between Example 9 and Example 3 is that the core material in Example 9 does not add epoxidized soybean oil, only dicyclopentadiene is added.

[0049] Example 10 Example 10 is based on Example 3, the difference between Example 10 and Example 3 is that in Example 10, calcium aluminate is also added in the filler, and the mass ratio of nano-silica and calcium aluminate in the filler is 1:0.01.

[0050] Preparation of asphalt pavement crack filling material 45 parts of asphalt, 12.5 parts of rubber powder, 9 parts of SBS modifier, 25 parts of self-healing microcapsule, 6.5 parts of dioctyl phthalate, 3 parts of polyethylene wax, 20 parts of filler, 0.75 parts of anti-aging agent; the asphalt is 70# petroleum asphalt, the rubber powder is 80 mesh, the SBS modifier is Hainan Balin SBS792E, the filler is composed of nano-silica and calcium aluminate with a mass ratio of 1:0.01, and the anti-aging agent is composed of UV-326 and HALS-770 with a mass ratio of 1:1.

[0051] The asphalt is heated to complete melting, the rubber powder and the SBS modifier are added, stirred at 600 rpm for 1.5 h at 170°C, the dioctyl phthalate and the polyethylene wax are added, stirred at 600 rpm for 0.5 h at 170°C, the nano-silica and the anti-aging agent are added, stirred at 400 rpm for 0.5 h at 130°C, the self-healing microcapsule is added, and stirred at 100 rpm for 30 min at 80°C, to obtain the asphalt pavement crack filling material.

[0052] Example 11 Example 11 is based on Example 10, the difference between Example 11 and Example 10 is that in Example 11, the mass ratio of nano-silica and calcium aluminate in the filler is 1:0.03.

[0053] Example 12 Example 12 is based on Example 10, the difference between Example 12 and Example 10 is that in Example 12, the mass ratio of nano-silica and calcium aluminate in the filler is 1:0.02.

[0054] Example 13 Example 13 is based on Example 10, the difference between Example 13 and Example 10 is that in Example 13, the mass ratio of nano-silica and calcium aluminate in the filler is 1:0.005.

[0055] Example 14 Example 14 is based on Example 10, the difference between Example 14 and Example 10 is that in Example 14, the mass ratio of nano-silica and calcium aluminate in the filler is 1:0.05.

[0056] Example 15 Example 15 is based on Example 10, the difference between Example 15 and Example 10 is only that the filler in Example 15 is modified, which is prepared by the following steps: The nanosilica and γ-aminopropyl triethoxysilane are mixed into ethanol, the mass ratio of nanosilica, γ-aminopropyl triethoxysilane and ethanol is 1:0.02:10, the pH is adjusted to 4 using glacial acetic acid, the reaction is stirred at 60°C at a speed of 200 rpm for 2h, after the reaction is completed, centrifugation is performed, washed with ethanol, and vacuum dried at 60°C to obtain modified silica; the modified silica and calcium aluminate are mixed according to a mass ratio of 1:0.01, ball milled at a speed of 300 rpm for 20 min to obtain a modified filler.

[0057] Example 16 Example 16 is based on Example 3, the difference between Example 16 and Example 3 is only that the filler in Example 16 is calcium aluminate.

[0058] Preparation of asphalt pavement crack filling material 45 parts of asphalt, 12.5 parts of rubber powder, 9 parts of SBS modifier, 25 parts of self-healing microcapsules, 6.5 parts of dioctyl phthalate, 3 parts of polyethylene wax, 0.2 parts of filler, 0.75 parts of anti-aging agent; the asphalt is 70# petroleum asphalt, the rubber powder is 80 mesh, the SBS modifier is Hainan Balin SBS792E, the filler is calcium aluminate, and the anti-aging agent is composed of UV-326 and HALS-770 in a mass ratio of 1:1.

[0059] The asphalt is heated to complete melting, the rubber powder and SBS modifier are added, stirred at a speed of 600 rpm at 170°C for 1.5h, the dioctyl phthalate and polyethylene wax are added, stirred at a speed of 600 rpm at 170°C for 0.5h, the nanosilica and anti-aging agent are added, stirred at a speed of 400 rpm at 130°C for 0.5h, the self-healing microcapsules are added, and stirred at a speed of 100 rpm at 80°C for 30 min to obtain the asphalt pavement crack filling material.

[0060] Example 17 Example 17 is based on Example 3, the difference between Example 17 and Example 3 is only that the raw materials for preparing the asphalt pavement crack filling material in Example 17 further include 1 part of maleic anhydride grafted SBS.

[0061] Preparation of asphalt pavement crack filling material Weigh 45 parts of asphalt, 12.5 parts of rubber powder, 9 parts of SBS modifier, 25 parts of self-healing microcapsules, 6.5 parts of dioctyl phthalate, 3 parts of polyethylene wax, 20 parts of filler, 0.75 parts of anti-aging agent, and 1 part of maleic anhydride grafted SBS; the asphalt is 70# petroleum asphalt, the rubber powder is 80 mesh, the SBS modifier model is Hainan Baling SBS792E, the filler is nano-silica, and the anti-aging agent is composed of UV-326 and HALS-770 in a mass ratio of 1:1.

[0062] The asphalt was heated until completely melted, and rubber powder, SBS modifier and maleic anhydride grafted SBS were added in sequence, and stirred at 600 rpm at 170°C for 1.5 h. Dioctyl phthalate and polyethylene wax were added, and stirred at 600 rpm at 170°C for 0.5 h. Nano-silica and anti-aging agent were added, and stirred at 400 rpm at 130°C for 0.5 h. Self-healing microcapsules were added, and stirred at 100 rpm at 80°C for 30 min to obtain asphalt pavement filling material.

[0063] Example 18 Example 18 is based on Example 17. The only difference between Example 18 and Example 17 is that 2 parts of maleic anhydride-grafted SBS are added in Example 18.

[0064] Example 19 Example 19 is based on Example 17. The only difference between Example 19 and Example 17 is that in Example 19, 1.5 parts of maleic anhydride-grafted SBS are added.

[0065] Example 20 Example 20 is based on Example 17. The only difference between Example 20 and Example 17 is that in Example 20, 0.5 parts of maleic anhydride-grafted SBS is added.

[0066] Example 21 Example 21 is based on Example 17. The only difference between Example 21 and Example 17 is that 3 parts of maleic anhydride-grafted SBS are added.

[0067] Comparative Example 1 Comparative Example 1 is based on Example 3. The only difference between Comparative Example 1 and Example 3 is that self-repairing microcapsules are not added in Comparative Example 1.

[0068] Preparation of asphalt pavement crack filling materials 45 parts of asphalt, 12.5 parts of rubber powder, 9 parts of SBS modifier, 6.5 parts of dioctyl phthalate, 3 parts of polyethylene wax, 20 parts of filler, 0.75 parts of anti-aging agent; the asphalt is 70# petroleum asphalt, the rubber powder is 80 mesh, the SBS modifier is Hainan Balin SBS792E, the filler is nano silicon dioxide, and the anti-aging agent is composed of UV-326 and HALS-770 in a mass ratio of 1:1.

[0069] The asphalt is heated to complete melting, the rubber powder and the SBS modifier are added, stirring at 600 rpm for 1.5 h at 170℃, the dioctyl phthalate and the polyethylene wax are added, stirring at 600 rpm for 0.5 h at 170℃, the nano silicon dioxide and the anti-aging agent are added, stirring at 400 rpm for 0.5 h at 130℃, to obtain the asphalt pavement crack pouring material.

[0070] Performance test (1) Select “GB / T 16777-2008 Building Waterproof Coating Test Method” as the standard, apply the sample to the concrete base plate, the bonding area is a circle with a diameter of 50 mm and a thickness of 2 mm, use a tensile testing machine to vertically stretch to failure at a speed of 50 mm / min, record the maximum load and the bonding area, calculate the bonding strength, test each sample three times, take the average value after measurement, and record the results in Table 1.

[0071] (2) Select “GB / T 4508-2010 Asphalt Ductility Test Method” as the standard, place the crack pouring material sample (standard 8-shaped mold) into a UV aging box, irradiate for 500 h at 60℃, stretch to break in a 5℃±0.5℃ water bath at a speed of 5 cm / min, respectively test the ductility values before and after aging, calculate the low-temperature ductility retention rate, and record the results in Table 1.

[0072] (3) Select “JTG E20-2011 Highway Engineering Asphalt and Asphalt Mixture Test Regulations” as the standard, pour the crack pouring material into a pre-cracked concrete test piece (crack width 0.5 mm), maintain for 48 h, after the test piece is saturated with water, freeze at -18℃ for 16 h, melt in a 25℃ water bath for 8 h for one cycle, repeat for 20 times, use a crack observation instrument to measure the crack width, compare with the initial width, calculate the crack recurrence rate, and record the results in Table 1.

[0073] Table 1 Detection results of the bonding performance and durability of the asphalt pavement crack pouring material Test results Adhesive strength (MPa) Low temperature ductility retention rate (%) Crack reoccurrence rate (%) Example 1 1.39 85.7 5.3 Example 2 1.41 85.9 5.2 Example 3 1.44 86.4 4.9 Example 4 1.48 88.9 4.1 Example 5 1.51 89.3 4.0 Example 6 1.52 89.5 3.8 Example 7 1.46 86.9 4.4 Example 8 1.45 87.2 4.6 Example 9 1.28 85.7 6.8 Example 10 1.60 88.4 4.2 Example 11 1.62 88.7 4.1 Example 12 1.63 88.9 3.9 Example 13 1.55 87.1 4.7 Example 14 1.52 86.9 4.8 Example 15 1.68 90.3 3.2 Example 16 1.35 84.3 7.5 Example 17 1.65 89.3 4.2 Example 18 1.68 89.6 3.9 Example 19 1.72 89.7 3.7 Example 20 1.55 88.2 4.7 Example 21 1.62 88.8 4.5 Comparative Example 1 1.18 68.5 15.3 As can be seen from Table 1, the bonding strength of Examples 1-3 is greater than 1.39 MPa, the low-temperature ductility retention rate is greater than 85.7%, and the crack recurrence rate is less than 5.3%, so it can be seen that the crack pouring material prepared in the application has good adhesion performance and durability.

[0074] From Table 1, it can be seen that the difference between Examples 4-9 and Example 3 is only that: in Examples 4-6, dicyclopentadiene and epoxidized soybean oil are used in the optimal ratio to form a compound as the core material, and the two have a synergistic effect, effectively improving the repair performance of the microcapsule, thereby improving the performance of the crack pouring material; in Examples 7 and 8, the optimal ratio range is destroyed, and the performance decreases; in Example 9, the core material is replaced by dicyclopentadiene, and the performance decreases significantly due to the lack of synergistic effect.

[0075] From Table 1, it can be seen that the difference between Examples 10-16 and Example 3 is only that: in Examples 10-12, nano-silicon dioxide and calcium aluminate are compounded and have a synergistic effect, and within the optimal ratio, they have a good improvement effect; in Examples 13 and 14, the optimal ratio is destroyed, and the performance decreases; in Example 15, the compounded filler is modified to improve compatibility and synergistic effect, and the performance further increases; in Example 16, the filler is replaced by calcium aluminate, and the performance decreases significantly due to the lack of synergistic effect between fillers.

[0076] From Table 1, it can be seen that the difference between Examples 17-21 and Example 3 is only that: in Examples 17-19, maleic anhydride grafted SBS is added, and within the optimal dosage range, it can effectively improve the compatibility between components, thereby improving the synergistic effect and the performance increases; in Examples 20 and 21, the optimal dosage range is destroyed, and the performance decreases.

[0077] From Table 1, it can be seen that the difference between Comparative Example 1 and Example 3 is only that: no self-repairing microcapsule is added in Comparative Example 1, and the performance of Comparative Example 1 and Example 3 decreases significantly; this is because the self-healing performance of the crack pouring material decreases without the addition of self-repairing microcapsules, and the adhesion performance and durability become poor.

[0078] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application. Through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the content of the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. An asphalt pavement crack filling material, characterized by: The raw materials for preparation include the following components in parts by weight: 40-50 parts asphalt 10-15 parts rubber powder 8-10 parts of SBS modifier 20-30 portions of self-healing microcapsules 5-8 parts of dioctyl phthalate 2-4 parts polyethylene wax 15-25 parts of filler 0.5-1 part of anti-aging agent; The filler includes nano-silicon dioxide; The self-healing microcapsules are prepared by the following steps: The core material and alkylphenol polyoxyethylene ether are added to water, dicyandiamide is added, and the mixture is heated and stirred for emulsification to obtain an emulsion, wherein the core material includes epoxidized soybean oil; urea and formaldehyde are mixed, the pH is adjusted to alkaline, and the mixture is heated and stirred for reaction to obtain a urea-formaldehyde resin prepolymer; the urea-formaldehyde resin prepolymer is added to the emulsion, the pH is adjusted to acidic, and the mixture is heated and stirred for reaction. After the reaction is completed, the pH is adjusted to neutral, and the mixture is centrifuged, washed, and dried to obtain self-healing microcapsules.

2. The asphalt pavement crack filling material according to claim 1, characterized in that: The core material further comprises dicyclopentadiene.

3. The asphalt pavement crack filling material according to claim 2, characterized in that: The mass ratio of dicyclopentadiene to epoxy soybean oil in the core material is (0.15-0.25):

1.

4. The asphalt pavement crack filling material according to claim 1, characterized in that: The filler also includes ettringite.

5. The asphalt pavement crack filling material according to claim 4, characterized in that: The mass ratio of nano-silicon dioxide to ettringite in the filler is 1:(0.01-0.03).

6. The asphalt pavement crack filling material according to claim 5, characterized in that: The filler is modified and prepared by the following steps: Nano-silica and gamma-aminopropyltriethoxysilane are mixed into a solvent, the pH is adjusted to acidic, heating and stirring are carried out for reaction, and after the reaction is completed, the mixture is centrifuged, washed, and dried to obtain modified silica; and the modified silica and ettringite are mixed and ball-milled to obtain a modified filler.

7. The asphalt pavement crack filling material according to claim 1, characterized in that: The preparation raw materials also include maleic anhydride grafted SBS.

8. The asphalt pavement crack filling material according to claim 7, characterized in that: The amount of the maleic anhydride grafted SBS is 1-2 parts.

9. The asphalt pavement crack filling material according to claim 1, characterized in that: The anti-aging agent includes a benzotriazole ultraviolet absorber and a hindered amine light stabilizer.

10. A method for preparing the asphalt pavement crack filling material according to any one of claims 1 to 9, characterized in that: The following steps are involved: The asphalt is heated until completely melted, rubber powder and SBS modifier are added, dioctyl phthalate and polyethylene wax are added after heating and stirring, nano silicon dioxide and anti-aging agent are added after heating and stirring, self-healing microcapsules are added after heating and stirring, and asphalt pavement caulking material is obtained after heating and stirring.