Polyphosphoric acid-polymer complex modified asphalt and method for preparing the same

Abstract

The application provides a polyphosphoric acid-polymer composite modified asphalt and a preparation method thereof. The asphalt comprises the following components by weight parts: 100 parts of base asphalt, 0.5-3 parts of polyphosphoric acid, 0.1-0.5 parts of a stabilizer, 2-5 parts of a bio-based plasticizer, 5-15 parts of elastomer particles, 0.5-2 parts of nano-enhanced fillers, 1-5 parts of SEBS, 2-5 parts of APAO and 1-3 parts of organic montmorillonite. The base asphalt is modified by various modifiers, so that the modified asphalt has excellent low-temperature performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pavement engineering materials, and particularly relates to a polyphosphoric acid-polymer composite modified asphalt and a preparation method thereof. BACKGROUND

[0002] Polymer modified asphalt is widely used in highways, airport runways, bridges and building waterproof engineering. Due to its excellent high and low temperature performance, the road performance and service life can be significantly improved, and the complex climate and heavy traffic demand can be met.

[0003] Common modifiers SBS (styrene-butadiene-styrene triblock copolymer) and SBR (styrene-butadiene rubber) modify asphalt, so that the modified asphalt has excellent high-temperature rut resistance, low-temperature crack resistance, fatigue resistance and excellent elastic recovery capacity, and is mainly applied to the upper layer of highways, road sections with more heavy traffic and overload vehicles and other high-grade pavements. Based on the above excellent road performance, SBS modified asphalt has become the mainstream product in modified asphalt. However, the addition amount of SBS is too large, the cost is too high, and SBS has poor weather resistance and aging resistance due to the unsaturated double bond in the molecular structure. At the same time, polyphosphoric acid (PPA) is a low-cost asphalt modifier, which is widely used in polymer modified asphalt. The addition of PPA can significantly improve the high-temperature performance of SBS and SBR modified asphalt, but the polyphosphoric acid modified asphalt has insufficient low-temperature ductility and crack resistance. Under low-temperature conditions, the pavement is prone to brittle crust, the asphalt mixture arches, loses the flatness of the pavement, and also has the problem of segregation due to high viscosity during construction. SUMMARY

[0004] The present application provides a polyphosphoric acid-polymer composite modified asphalt and a preparation method thereof to solve the above problems mentioned in the background.

[0005] The present application provides a polyphosphoric acid-polymer composite modified asphalt, which comprises the following components by weight:

[0006] 100 parts by weight of base asphalt, 0.5-3 parts by weight of polyphosphoric acid, 0.1-0.5 parts by weight of stabilizer, 2-5 parts by weight of bio-based plasticizer, 5-15 parts by weight of elastomer particles, 0.5-2 parts by weight of nano-enhanced filler, 1-5 parts by weight of SEBS, 2-5 parts by weight of APAO, and 1-3 parts by weight of organic montmorillonite.

[0007] Optionally, 0.05-0.4 parts by weight of a crack resistance agent is further added to the asphalt, and the crack resistance agent is obtained by mixing nonylphenol polyoxyethylene ether, benzoic anhydride and 1-amino-8-naphthol-4,6-disulfonic acid in a mass ratio of 1:0:55-4.5:1-2.5.

[0008] Optionally, the polyphosphoric acid is an industrial pure reagent, and the purity is not less than 85% according to the content of phosphorus pentoxide.

[0009] Optionally, the stabilizer is selected from sulfur or an organic silicon coupling agent.

[0010] Optionally, the bio-based plasticizer is selected from epoxy soybean oil acrylate.

[0011] Optionally, the epoxy value of the epoxy soybean oil acrylate is 6.0%-6.5%.

[0012] Optionally, the elastomer particles are selected from activated rubber powder, and the particle size of the activated rubber powder is 80-120 mesh.

[0013] Optionally, the nano-enhanced filler includes at least one of graphene oxide and nano-zinc oxide.

[0014] Optionally, the base asphalt includes one or more of 70# base asphalt, 110# base asphalt, 130# base asphalt, and 140# base asphalt.

[0015] In another aspect, the application provides a preparation method of polyphosphoric acid-polymer composite modified asphalt, which is used for preparing the modified asphalt described above, and the preparation method includes the following steps:

[0016] (1) According to the weight part, the base asphalt is heated to 160-170°C, the polyphosphoric acid is added to the base asphalt, and high-speed shearing is performed at a speed of 5000-5500 r / min until it is uniformly dispersed. After shearing, it is developed at 165°C for 30 min;

[0017] (2) The asphalt obtained in step (1) is heated to 170-180°C, and the bio-plasticizer and the stabilizer are added according to the weight part, and stirred at a speed of 5000-5500 r / min for 30 min;

[0018] (3) According to the weight part, the activated rubber powder, SEBS and APAO are added to the asphalt obtained in step (2), and high-speed shearing is performed at a speed of 5000 r / min and a speed of 180°C for 1 h;

[0019] (4) According to the weight part, benzoic anhydride is added to the asphalt obtained in step (3), and stirred at a speed of 3000-5000 r / min for 5-10 min, and nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4,6-disulfonic acid are added, and stirred at a speed of 5000-5500 r / min for 20-30 min;

[0020] (5) Add the nano filler and organic montmorillonite into the asphalt obtained in step (4), and keep the high-speed shearing at 180 DEG C and 5000-5500 r / min for 2 h, and then develop at 170-180 DEG C for 2 h after the shearing, to obtain the polyphosphoric acid-polymer composite modified asphalt.

[0021] The polyphosphoric acid-polymer composite modified asphalt and the preparation method thereof provided in the application realize the preparation of the polyphosphoric acid-polymer composite modified asphalt, and have the following beneficial effects compared with the prior art:

[0022] (1) The application realizes the reaction of the polyphosphoric acid and the active site in the asphalt molecules, the dispersity of the asphaltene in the soft component of the asphalt is enhanced, the information crosslinking structure, the liposoluble group and the polyanion group structure in the molecular structure of the asphaltene make the asphaltene have good adhesion and passivation effect in the asphalt, and the elastic recovery capacity of the asphalt is increased through the chemical crosslinking, so that the stability and the shear resistance of the asphalt are improved. The synergistic effect of SEBS and PPA forms a "double network" structure, the PPA crosslinking network provides rigid support, the SEBS elastic network absorbs energy, and the orientation and recombination of the asphalt molecular chain are limited together. The elastomer particles significantly improve the crack resistance and toughness of the asphalt at low temperature, and the SEBS is combined with each other in the matrix asphalt, the viscosity of the asphalt is increased, a relatively stable crosslinking structure is formed, and the low-temperature crack resistance and the storage stability are improved. The synergistic effect is formed among the polyphosphoric acid (PPA), the bio-based plasticizing compatibilizer and the elastomer particles. The bio-based plasticizing can improve the compatibility and the mixing of the modified asphalt, can effectively interact with the asphalt matrix, and improve the compatibility of the asphalt matrix with SEBS and the elastomer particles. At the same time, the viscosity of the asphalt after the incorporation of the elastomer particles is greatly reduced, the segregation problem caused by the high viscosity of the asphalt during construction is improved, the phase separation and the delamination phenomenon in the modified asphalt are reduced, and the stability and the consistency of the modified asphalt are improved.

[0023] (2) By adding anti-cracking agent, including nonyl phenol polyoxyethylene ether, benzoic anhydride and 1-amino-8-naphthol-4, 6-disulfonic acid, the hydroxyl contained in the nonyl phenol polyoxyethylene ether reacts with the asphalt surface active group, so that the long chain alkyl is free on the outside of the asphalt particles, part of the amino, hydroxyl, sulfonic acid group of 1-amino-8-naphthol-4, 6-disulfonic acid reacts with the active site on the surface of asphalt, at the same time, the long chain alkyl of nonyl phenol polyoxyethylene ether is easier to attack the surface of asphalt than 1-amino-8-naphthol-4, 6-disulfonic acid, therefore, the remaining 1-amino-8-naphthol-4, 6-disulfonic acid is wrapped on the surface of the asphalt particles modified by SEBS and PPA, a multi-phase composite structure is formed between each modifier and asphalt, when the modified asphalt is used in low temperature environment, the composite structure can buffer the stress generated by low temperature, thereby improving the low temperature performance of the modified asphalt, reducing the embrittlement and cracking of the modified asphalt due to temperature reduction. Benzoic anhydride is also used to adjust the acidity and alkalinity during the preparation of modified asphalt, before adding nonyl phenol polyoxyethylene ether and 1-amino-8-naphthol-4, 6-disulfonic acid, the pH value of the system is maintained between 5.5-7, which is helpful for the reaction of nonyl phenol polyoxyethylene ether and 1-amino-8-naphthol-4, 6-disulfonic acid with asphalt, and facilitates the stable formation of multi-phase composite structure, so as to ensure the low temperature stability and crack resistance of the modified asphalt.

[0024] (3) The modified asphalt provided by the present application has simple and fast preparation method, which can be completed by only simple stirring equipment, and not only retains good high temperature performance, but also improves low temperature performance, so that the modified asphalt provided by the present application can be applied in a wider range and can be produced on a large scale. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor also belong to the scope of protection of the present application.

[0026] The present application provides a polyphosphoric acid-polymer composite modified asphalt, which comprises the following components by weight:

[0027] 100 parts by weight of base asphalt, 0.5-3 parts by weight of polyphosphoric acid, 0.1-0.5 parts by weight of stabilizer, 2-5 parts by weight of bio-based plasticizer, 5-15 parts by weight of elastomer particles, 0.5-2 parts by weight of nano-enhanced filler, 1-5 parts by weight of SEBS, 2-5 parts by weight of APAO, and 1-3 parts by weight of organic montmorillonite.

[0028] Specifically, in this application, the rigidity caused by oxidation is reduced, the flexibility is improved, and the anti-aging performance is improved by the non-reactive butadiene segment in the SEBS molecule; at the same time, the problems of low-temperature ductility and insufficient crack resistance of polyphosphoric acid modified asphalt are solved. The use of organic montmorillonite and nano-enhanced fillers improves the storage stability of SEBS modified asphalt. Epoxy soybean oil as a compatibilizer not only enhances the compatibility and miscibility of modified asphalt, but also significantly reduces the viscosity after the addition of rubber powder, solves the problem of segregation caused by high viscosity during construction, and improves the compatibility with SEBS and rubber powder, reduces phase separation and delamination, and improves the stability of the modified asphalt.

[0029] Polyphosphoric acid (PPA) is a water-soluble polymer that can be combined with asphalt particles on the surface to form a film layer, which can block the penetration of oxygen and moisture, effectively extend the service life of asphalt, and improve the durability and maintainability of the road. Polyphosphoric acid reacts with active sites (hydroxyl, imino, sulfide) in the asphalt molecule, breaking the asphaltene clusters and enhancing the dispersity of asphaltene in the soft component of asphalt. The dispersed asphaltene can form a stable spatial grid, and the special structures such as information crosslinking structure, lipid-soluble group and polyanion group in its molecular structure make it have good adhesion and passivation effect in asphalt. At the same time, through chemical crosslinking, the elastic recovery capacity of asphalt is increased, the initial stress value is reduced, and the intermolecular interaction force is increased, thereby improving the stability and shear resistance of asphalt.

[0030] The physical network of SEBS (styrene-ethylene / butylene-styrene block copolymer) can maintain the elastic skeleton at high temperature, delaying the irreversible deformation of the molecular chain. In addition, PPA can effectively improve the storage stability of polymer modified asphalt by preventing SEBS from agglomerating and increasing the interfacial energy between the matrix asphalt and the SEBS molecule. The synergistic effect of SEBS and PPA forms a "double network" structure, the PPA crosslinking network provides rigid support, and the SEBS elastic network absorbs energy, which together limits the orientation and recombination of asphalt molecular chains. The SEBS molecules in the modified asphalt can still maintain partial elasticity after aging, improving the low-temperature deformation capacity of the modified asphalt.

[0031] SEBS (styrene-ethylene-butadiene-styrene) is a polymer obtained by hydrogenation of SBS (styrene-butadiene-styrene). SEBS is a polymer modifier prepared by hydrogenation of the unsaturated carbon-carbon double bonds of SBS, which has almost no unsaturated double bonds in its molecular chain, good heat resistance, excellent oxidation resistance and ultraviolet aging resistance. The content of styrene is 35%, the hardness is 72, the tensile stress is greater than 5.50 MPa, and the elongation is greater than 500%.

[0032] The addition of the stabilizer can improve the anti-aging performance and anti-oxidation performance of the modified asphalt. Meanwhile, the stabilizer has strong anti-oxidation and anti-aging effects, and can prevent oxidation reactions and molecular chain breakage in the asphalt. The bio-based plasticizer can improve the low-temperature performance, water stability and environmental protection performance of the asphalt. The bio-based plasticizer can make the asphalt more flexible by improving the flexibility, ductility and plasticity of the asphalt, so as to reduce the cracking and warping rate of the pavement and improve the anti-cracking performance of the asphalt at low temperatures.

[0033] The elastomer particles are uniformly dispersed in the base asphalt, which can significantly improve the anti-cracking performance and toughness of the asphalt at low temperatures, so that the modified asphalt can be widely used in cold regions, and the modified asphalt can quickly recover to the original state when subjected to external force, thereby improving the waterproof performance of the modified asphalt.

[0034] The nano-enhanced filler has a high specific surface area, can be uniformly dispersed in the asphalt, and can adsorb asphalt particles, so as to significantly improve the elastic modulus and anti-deformation capacity of the modified asphalt, improve the mechanical properties of the modified asphalt, and improve the durability and pit aging performance of the asphalt. The nano-enhanced filler can significantly improve the self-repairing capacity of the asphalt, and improve the anti-fatigue performance, anti-rutting performance and anti-cracking performance of the asphalt.

[0035] The asphalt is modified by using APAO (amorphous alpha-olefin copolymer) and SEBS, which can effectively improve the anti-aging performance of the asphalt. By adding APAO, the amount of SEBS can be reduced to reduce the cost, and the compatibility of the asphalt is good. The two are re-mixed to improve the anti-aging performance of the asphalt, which can reduce the pavement diseases caused by asphalt aging under high-temperature climate conditions in summer in high-temperature regions. The APAO is VESTOPLAST 828 type APAO modifier, which is a colorless granular solid.

[0036] The organic montmorillonite is mixed with the asphalt by intercalation method, which can significantly improve the high-temperature performance, anti-aging performance and barrier performance of the asphalt. Due to the poor compatibility of SEBS with the asphalt, the segregation phenomenon of the SEBS modified asphalt is relatively serious. After the addition of the organic montmorillonite (OMMT), the thermal storage stability of the SEBS modified asphalt is significantly improved, and the performance of the SEBS modified asphalt after aging is also improved.

[0037] The application realizes preparation of the polyphosphoric acid-polymer composite modified asphalt. The asphaltene clusters are broken through the reaction of the polyphosphoric acid and the active sites (hydroxyl, imino, sulfide) in the asphalt molecules, the dispersivity of the asphaltene in the soft component of the asphalt is enhanced, the dispersed asphaltene can form a stable space grid, the information crosslinking structure, the lipid-soluble group and the polyanion group structure in the molecular structure of the asphaltene enable the asphaltene to have good adhesion and passivation effect in the asphalt, the elasticity recovery capacity of the asphalt is increased through the chemical crosslinking, the initial stress value is reduced, and the intermolecular interaction force of the asphalt is increased, so that the stability and the shear resistance of the asphalt are improved. The synergistic effect of the SEBS and the PPA forms a "double network" structure, the PPA crosslinking network provides rigid support, and the SEBS elastic network absorbs energy, so as to jointly limit the orientation and recombination of the asphalt molecular chain. The SEBS molecules in the modified asphalt can still maintain partial elasticity after aging, so that the low-temperature deformation capacity of the modified asphalt is improved. The elastomer particles significantly improve the crack resistance and toughness of the asphalt at low temperature, and at the same time, the SEBS is combined with each other in the matrix asphalt, the viscosity of the asphalt is increased, a relatively stable crosslinking structure is formed, so that the low-temperature crack resistance and the storage stability are improved. And the synergistic effect is formed among the polyphosphoric acid (PPA), the bio-based plasticizing compatibilizer and the elastomer particles. The bio-based plasticizing can improve the compatibility and the mixing of the modified asphalt, can effectively interact with the asphalt matrix, and improve the compatibility of the modified asphalt with the SEBS and the elastomer particles. At the same time, the viscosity of the asphalt after the incorporation of the elastomer particles is greatly reduced, the segregation problem caused by the too high viscosity of the asphalt during construction is improved, the phase separation and the delamination phenomenon in the modified asphalt are reduced, and the stability and the consistency of the modified asphalt are improved.

[0038] Optionally, 0.05-0.4 parts by weight of an anti-cracking agent is further added to the asphalt, the anti-cracking agent is obtained by mixing nonylphenol polyoxyethylene ether, benzoic anhydride and 1-amino-8-naphthol-4, 6-disulfonic acid at a mass ratio of 1:0.55-4.5:1-2.5.

[0039] Specifically, the crack-resistant agent, when mixed with asphalt, forms a stable multiphase composite structure. The synergistic effect between these phases improves the tensile strength and crack resistance of the asphalt mixture, reducing pavement cracking. The crack-resistant agent comprises nonylphenol polyoxyethylene ether, benzoic anhydride, and 1-amino-8-naphthol-4,6-disulfonic acid. Nonylphenol polyoxyethylene ether contains long-chain alkanes, and 1-amino-8-naphthol-4,6-disulfonic acid contains aromatic rings. The hydroxyl groups in nonylphenol polyoxyethylene ether react with the active groups on the asphalt surface, allowing long-chain alkyl groups to become free on the outside of the asphalt particles. Simultaneously, some of the amino, hydroxyl, and sulfonic acid groups in 1-amino-8-naphthol-4,6-disulfonic acid react with the active sites on the asphalt surface, further modifying the asphalt. Meanwhile, the long-chain alkyl groups of nonylphenol polyoxyethylene ether are more likely to attack the asphalt surface than 1-amino-8-naphthol-4,6-disulfonic acid. Therefore, the remaining 1-amino-8-naphthol-4,6-disulfonic acid is coated on the outer surface of the asphalt particles modified by SEBS and PPA. A multiphase composite structure is formed between each modifier and the asphalt. When the modified asphalt is used in a low-temperature environment, the composite structure can buffer the stress generated by the low temperature, thereby improving the low-temperature performance of the modified asphalt and reducing the embrittlement and cracking of the modified asphalt due to the decrease in temperature.

[0040] Meanwhile, benzoic anhydride is used to adjust the pH during the preparation of modified asphalt. Before adding nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4,6-disulfonic acid, the pH of the system is maintained between 5.5 and 7, which helps the reaction of nonylphenol polyoxyethylene ether, 1-amino-8-naphthol-4,6-disulfonic acid with asphalt, and facilitates the stable formation of multiphase composite structure, so as to ensure the low-temperature stability and crack resistance of modified asphalt.

[0041] Furthermore, by controlling the mass ratio of nonylphenol polyoxyethylene ether, benzoic anhydride, and 1-amino-8-naphthol-4,6-disulfonic acid, the proportion of long-chain alkyl groups and aromatic rings in the crack-resistant agent can be controlled. This avoids excessive addition of aromatic rings, which would lead to excessive rigidity in the modified asphalt, hindering its deformation at low temperatures, and thus improving the low-temperature crack resistance of the modified asphalt.

[0042] Optionally, the polyphosphoric acid is an industrial-grade reagent with a purity of not less than 85% based on phosphorus pentoxide content.

[0043] Optionally, the stabilizer may be selected from sulfur or organosilicon coupling agents.

[0044] Specifically, stabilizers can improve the anti-aging and anti-oxidation properties of modified asphalt, and can prevent oxidation reactions and molecular chain breakage in asphalt. They can react with free radicals and oxidation products in asphalt to form stable compounds, effectively delaying the aging process of modified asphalt, enhancing its resistance to dissolution, reducing its fluidity under high-temperature conditions, and improving the stability and durability of the pavement.

[0045] wherein the organosilicon coupling agent is selected from at least one of an aminosilane coupling agent (such as N-(beta-aminoethyl)-gamma-aminopropyltrimethoxysilane), an epoxy silane coupling agent (such as glycidyloxypropyltrimethoxysilane), a vinyl silane coupling agent (such as vinyltrimethoxysilane, CAS No. 2768-02-7), a methacryloxy silane (such as gamma-methacryloxypropyltrimethoxysilane).

[0046] Optionally, the bio-based plasticizer is selected from epoxy soybean oil acrylate.

[0047] Optionally, the epoxy value of the epoxy soybean oil acrylate is 6.0%-6.5%.

[0048] Specifically, the bio-based plasticizer as a compatibilizer can improve the compatibility and mixability of the modified asphalt, while greatly reducing the viscosity of the asphalt after the incorporation of the elastomer particles, improving the related problems of segregation caused by too high viscosity during construction, and it can effectively interact with the asphalt matrix to improve its compatibility with SEBS and elastomer particles. This helps to reduce the phase separation and delamination in the modified asphalt, further improving the stability and consistency of the modified asphalt.

[0049] The application of bio-based plasticizer can also improve the environmental performance of asphalt. The bio-based material selected from epoxy soybean oil acrylate in the present application has biodegradability, can reduce the dependence on petrochemical resources, reduce environmental pollution, reduce the negative impact on the environment, has high compatibility with other components, improved processing performance and mechanical properties, can improve the ductility and plasticity of asphalt, making it more flexible, thereby reducing the incidence of cracking and warping of the road surface.

[0050] The bio-based plasticizer provides a certain relative movement ability between the three-dimensional network structure formed by the nano-enhanced filler, PPA and asphalt and the free asphalt molecules, so that the nano-enhanced filler and PPA can improve the overall strength after forming a whole with part of the matrix asphalt, while also giving it a certain flowability and flexibility, thereby improving its rheological properties at low temperature, so that it does not crack due to excessive brittleness at too low temperature, and can improve its fatigue resistance.

[0051] Optionally, the elastomer particles are selected from activated rubber powder, and the particle size of the activated rubber powder is 80-120 mesh.

[0052] Optionally, the nano-enhanced filler includes at least one of graphene oxide and nano-zinc oxide.

[0053] Specifically, the incorporation of graphene oxide reduces the penetration of asphalt, and has a higher softening point and ductility, improving the performance of asphalt. The modified asphalt is modified by nanometer graphene, and the modified asphalt is fully wrapped by the modified asphalt, and the swelling and adsorption phenomenon is obvious, and has better compatibility with the asphalt, and enhances the interface bonding of the asphalt and the rubber powder. Graphene oxide is made of 40-50um flaky graphite, and the specific surface area is 2500-5000m 2 / g, and the specific surface area of graphene oxide is too large, which leads to the difficulty of dispersion in the modification process and the formation of agglomeration, which cannot achieve the modification purpose of asphalt. If the specific surface area is too small, the compatibility of graphene oxide and asphalt is poor, and the segregation phenomenon is easy to occur. The method for preparing graphene oxide from flaky graphite is made by the prior art known by those skilled in the art (such as by strong acid and potassium permanganate oxidation, or by electrochemical oxidation method, which ensures that the specific surface area is 2500-5000m 2 / g, which is prior art and not the innovation point of the present application, and will not be described here.

[0054] Nanometer zinc oxide can enhance the diffusion capacity of polyphosphoric acid in the matrix asphalt, so that the cyclization and grafting reaction between polyphosphoric acid and asphalt components is more sufficient, and the anti-rutting ability of polyphosphoric acid modified asphalt in high temperature area is further enhanced. The nanometer reinforcing filler can also improve the storage stability, anti-aging performance and durability of the modified asphalt. Among them, the nanometer zinc oxide is a white hexagonal crystal or spherical particle, and the content of zinc oxide is greater than 99.0%.

[0055] Optionally, the matrix asphalt includes one or more of 70# matrix asphalt, 110# matrix asphalt, 130# matrix asphalt and 140# matrix asphalt.

[0056] On the other hand, the present application provides a preparation method of polyphosphoric acid-polymer composite modified asphalt, which is used to prepare the modified asphalt described above, and the preparation method comprises the following steps:

[0057] (1) according to the weight part, the matrix asphalt is heated to 160-170℃, the polyphosphoric acid is added to the matrix asphalt, and is sheared at a speed of 5000-5500r / min until it is uniformly dispersed, and after shearing, it is developed at 165℃ for 30min;

[0058] (2) the asphalt obtained in step (1) is heated to 170-180℃, and the biological plasticizer and the stabilizer are added according to the weight part, and stirred at a speed of 5000-5500r / min for 30min;

[0059] (3) according to weight parts, the activated glue powder, SEBS and APAO are added to the asphalt obtained in step (2), and high-speed shearing is kept at 180℃, 5000r / min for 1h;

[0060] (4) according to weight parts, benzoic anhydride is added to the asphalt obtained in step (3), stirring at 3000-5000r / min for 5-10min, then adding nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4, 6-disulfonic acid, and stirring at 5000-5500r / min for 20-30min;

[0061] (5) nano filler, organic montmorillonite is added to the asphalt obtained in step (4), and high-speed shearing is kept at 180℃, 5000-5500r / min for 2h, and then developed at 170-180℃ for 2h to obtain polyphosphoric acid-polymer composite modified asphalt.

[0062] Specifically, the base asphalt is heated to 160-170℃, the temperature is increased, which is convenient for the reaction of polyphosphoric acid and the active groups on the surface of the asphalt, and polyphosphoric acid is uniformly mixed with the base asphalt under high-speed shearing, which improves the modification reaction efficiency. Then develop for 30min at 165℃ to make the reaction of polyphosphoric acid and base asphalt more sufficient. Then the activated glue powder, SEBS and APAO are mixed with the polyphosphoric acid modified asphalt, and the anti-cracking agent is added. When adding benzoic anhydride, stirring and mixing, the pH value of the reaction system is kept between 5.5-7, then adding nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4, 6-disulfonic acid for reaction, forming a multiphase composite structure between each modifier and asphalt, which can relieve the sensitivity to temperature, and buffer the stress generated at low temperature, thereby improving the low temperature performance of the modified asphalt, reducing the embrittlement and cracking of the modified asphalt due to temperature reduction. Finally, nano filler and organic montmorillonite are added, the particle size of nano filler and organic montmorillonite is small, and the specific surface area is large, which can further disperse in the modified asphalt and enter the multiphase composite structure, reducing the viscosity of the modified asphalt and improving the high temperature and low temperature performance of the modified asphalt.

[0063] The technical scheme of the present application is illustrated in detail by specific examples as follows.

[0064] Example 1

[0065] A preparation method of polyphosphoric acid-polymer composite modified asphalt, the preparation method comprising the following steps:

[0066] (1) 100 parts by weight of base pitch was heated to 160°C, 0.5 parts by weight of polyphosphoric acid was added to the base pitch, and high-speed shearing was performed at a rotation speed of 5000 r / min until it was uniformly dispersed, and after the shearing was completed, development was performed at 165°C for 30 min;

[0067] (2) The pitch obtained in step (1) was heated to 170°C, 2 parts by weight of epoxy soybean oil acrylate and 0.1 parts by weight of sulfur were added, and stirring was performed at a rotation speed of 5000 r / min for 30 min;

[0068] (3) 5 parts by weight of activated rubber powder, 1 part by weight of SEBS, and 2 parts by weight of APAO were added to the pitch obtained in step (2), and high-speed shearing was performed at a temperature of 180°C and a rotation speed of 5000 r / min for 1 h;

[0069] (4) 0.5 parts by weight of graphene oxide and 1 part by weight of organic montmorillonite were added to the pitch obtained in step (3), and high-speed shearing was performed at a temperature of 180°C and a rotation speed of 5000 r / min for 2 h, and after the shearing was completed, development was performed at 170°C for 2 h, to obtain polyphosphoric acid-polymer composite modified pitch.

[0070] Example 2

[0071] A preparation method of polyphosphoric acid-polymer composite modified pitch, the preparation method comprising the following steps:

[0072] (1) 100 parts by weight of base pitch was heated to 165°C, 1.5 parts by weight of polyphosphoric acid was added to the base pitch, and high-speed shearing was performed at a rotation speed of 5300 r / min until it was uniformly dispersed, and after the shearing was completed, development was performed at 165°C for 30 min;

[0073] (2) The pitch obtained in step (1) was heated to 175°C, 2.5 parts by weight of epoxy soybean oil acrylate and 0.3 parts by weight of sulfur were added, and stirring was performed at a rotation speed of 5300 r / min for 30 min;

[0074] (3) 10 parts by weight of activated rubber powder, 3 parts by weight of SEBS, and 3.5 parts by weight of APAO were added to the pitch obtained in step (2), and high-speed shearing was performed at a temperature of 180°C and a rotation speed of 5000 r / min for 1 h;

[0075] (4) 1.2 parts by weight of graphene oxide and 2 parts by weight of organic montmorillonite were added to the pitch obtained in step (3), and high-speed shearing was performed at a temperature of 180°C and a rotation speed of 5300 r / min for 2 h, and after the shearing was completed, development was performed at 175°C for 2 h, to obtain polyphosphoric acid-polymer composite modified pitch.

[0076] Example 3

[0077] A preparation method of a polyphosphoric acid-polymer composite modified asphalt, the preparation method comprising the following steps:

[0078] (1) 100 parts by weight of base asphalt is heated to 165°C, 3 parts by weight of polyphosphoric acid is added to the base asphalt, and high-speed shearing is performed at a speed of 5300 r / min until it is uniformly dispersed, and after the shearing is completed, development is performed at 165°C for 30 min;

[0079] (2) The asphalt obtained in step (1) is heated to 175°C, 5 parts by weight of epoxy soybean oil acrylate and 0.5 parts by weight of sulfur are added, and stirring is performed at a speed of 5300 r / min for 30 min;

[0080] (3) 15 parts by weight of activated rubber powder, 5 parts by weight of SEBS, and 5 parts by weight of APAO are added to the asphalt obtained in step (2), and high-speed shearing is performed at a speed of 5000 r / min and at 180°C for 1 h;

[0081] (4) 2 parts by weight of graphene oxide and 3 parts by weight of organic montmorillonite are added to the asphalt obtained in step (3), and high-speed shearing is performed at a speed of 5300 r / min and at 180°C for 2 h, and after the shearing is completed, development is performed at 175°C for 2 h, to obtain a polyphosphoric acid-polymer composite modified asphalt.

[0082] Comparative Example 1

[0083] A preparation method of a polyphosphoric acid-polymer composite modified asphalt, the preparation method comprising the following steps:

[0084] The difference from Example 2 is that:

[0085] (1) 100 parts by weight of base asphalt is heated to 165°C, 1.5 parts by weight of polyphosphoric acid is added to the base asphalt, and high-speed shearing is performed at a speed of 5300 r / min until it is uniformly dispersed, and after the shearing is completed, development is performed at 165°C for 30 min;

[0086] (2) The asphalt obtained in step (1) is heated to 175°C, 5.1 parts by weight of epoxy soybean oil acrylate and 0.6 parts by weight of sulfur are added, and stirring is performed at a speed of 5300 r / min for 30 min;

[0087] (3) 16 parts by weight of activated rubber powder, 6 parts by weight of SEBS, and 3.5 parts by weight of APAO are added to the asphalt obtained in step (2), and high-speed shearing is performed at a speed of 5000 r / min and at 180°C for 1 h;

[0088] (4) 0.4 parts by weight of graphene oxide and 2 parts by weight of organic montmorillonite were added to the asphalt obtained in step (3), and high-speed shearing was performed at 180°C and a rotational speed of 5300 r / min for 2 h. After shearing, development was performed at 175°C for 2 h to obtain the polyphosphoric acid-polymer composite modified asphalt.

[0089] Comparative Example 2

[0090] A preparation method of a polyphosphoric acid-polymer composite modified asphalt, the preparation method comprising the following steps:

[0091] (1) 100 parts by weight of base asphalt was heated to 165°C, 0.4 parts by weight of polyphosphoric acid was added to the base asphalt, and high-speed shearing was performed at a rotational speed of 5300 r / min until the polyphosphoric acid was uniformly dispersed. After shearing, development was performed at 165°C for 30 min;

[0092] (2) The asphalt obtained in step (1) was heated to 175°C, 1.9 parts by weight of epoxy soybean oil acrylate and 0.3 parts by weight of sulfur were added, and stirring was performed at a rotational speed of 5300 r / min for 30 min;

[0093] (3) 10 parts by weight of activated rubber powder, 0.9 parts by weight of SEBS, and 3.5 parts by weight of APAO were added to the asphalt obtained in step (2), and high-speed shearing was performed at 180°C and a rotational speed of 5000 r / min for 1 h;

[0094] (4) 0.4 parts by weight of graphene oxide and 2 parts by weight of organic montmorillonite were added to the asphalt obtained in step (3), and high-speed shearing was performed at 180°C and a rotational speed of 5300 r / min for 2 h. After shearing, development was performed at 175°C for 2 h to obtain the polyphosphoric acid-polymer composite modified asphalt.

[0095] Experimental Example 1

[0096] The properties of the polyphosphoric acid-polymer composite modified asphalts obtained in Examples 1 to 3, Comparative Example 1, and Comparative Example 2 were detected, specifically including penetration (100 g, 25°C, 5 s), softening point, 5°C ductility, rut factor high-temperature index, creep stiffness modulus (-18°C), creep rate (-18°C), softening point difference (163°C), elastic recovery rate (25°C, 1 h), and short-term aging (163°C, 5 h) properties. Each test was performed at least 3 times in parallel, and the average value was taken to obtain the test results as shown in Table 1.

[0097] The performance detection was performed according to the detection methods and standards of JTG E20-2011 “Highway Engineering Asphalt and Asphalt Mixture Test Procedures”.

[0098] Table 1

[0099]

[0100] As can be seen from Table 1, the polyphosphoric acid-polymer composite modified asphalt provided by the application solves the problems of poor low-temperature performance of polyphosphoric acid modified asphalt, insufficient stability of SEBS modified asphalt, and poor interface compatibility of activated rubber powder and asphalt, and through the common modification of acrylate substances (ACR) and SEBS modifier, the SEBS molecules are intertwined in the matrix asphalt, the viscosity of the asphalt is increased, a relatively stable crosslinked structure is formed, and the polyphosphoric acid, epoxy soybean oil, and activated rubber powder form a synergistic effect to improve the stability and consistency of the modified asphalt, thereby improving the storage stability performance; the performance of the modified asphalt on the market after aging is greatly improved; the SEBS molecules can still maintain an elastic state to toughen the asphalt after aging, and the effect of graphene oxide and organic montmorillonite enables the asphalt to maintain good low-temperature crack resistance and stress relaxation capacity.

[0101] Example 4

[0102] A preparation method of a polyphosphoric acid-polymer composite modified asphalt, the preparation method comprising the following steps:

[0103] The difference from Example 2 is that:

[0104] (4) 0.05 parts by weight of a crack resistance agent is added, benzoic anhydride is first added to the asphalt obtained in step (3) to make the pH value of the reaction system 5.5, stirring is performed at a speed of 3000 r / min for 5 min, then nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4,6-disulfonic acid are added, and stirring is performed at a speed of 5000 r / min for 20 min; the mass ratio of nonylphenol polyoxyethylene ether to 1-amino-8-naphthol-4,6-disulfonic acid is 1:1;

[0105] (5) 2 parts by weight of graphene oxide and 3 parts by weight of organic montmorillonite are added to the asphalt obtained in step (4), and high-speed shearing is performed at 180°C and a speed of 5300 r / min for 2 h, and then development is performed at 175°C for 2 h to obtain the polyphosphoric acid-polymer composite modified asphalt.

[0106] Example 5

[0107] A preparation method of a polyphosphoric acid-polymer composite modified asphalt, the preparation method comprising the following steps:

[0108] The difference from Example 2 is that:

[0109] (4) 0.2 parts by weight of anti-cracking agent is added, benzoic anhydride is first added to the asphalt obtained in step (3) to make the pH value of the reaction system 6.5, stirring at 4000 r / min for 7 min, then adding nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4, 6-disulfonic acid, and stirring at 5300 r / min for 25 min; the mass ratio of nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4, 6-disulfonic acid is 1:1.5;

[0110] (5) 2 parts by weight of graphene oxide and 3 parts by weight of organic montmorillonite are added to the asphalt obtained in step (4), and high-speed shearing is carried out at 180°C and 5300 r / min for 2h, and then development is carried out at 175°C for 2h to obtain polyphosphoric acid-polymer composite modified asphalt.

[0111] Example 6

[0112] A preparation method of polyphosphoric acid-polymer composite modified asphalt, comprising the following steps:

[0113] The difference from example 2 is that:

[0114] (4) 0.4 parts by weight of anti-cracking agent is added, benzoic anhydride is first added to the asphalt obtained in step (3) to make the pH value of the reaction system 7, stirring at 5000 r / min for 10 min, then adding nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4, 6-disulfonic acid, and stirring at 5000 r / min for 30 min; the mass ratio of nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4, 6-disulfonic acid is 1:2.5;

[0115] (5) 2 parts by weight of graphene oxide and 3 parts by weight of organic montmorillonite are added to the asphalt obtained in step (4), and high-speed shearing is carried out at 180°C and 5300 r / min for 2h, and then development is carried out at 175°C for 2h to obtain polyphosphoric acid-polymer composite modified asphalt.

[0116] Comparative example 3

[0117] A preparation method of polyphosphoric acid-polymer composite modified asphalt, comprising the following steps:

[0118] The difference from example 5 is that:

[0119] (4) benzoic anhydride was added to the asphalt obtained in step (3) to make the pH value of the reaction system 5, stirring at a speed of 5000 r / min for 10 min, then adding nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4, 6-disulfonic acid, and stirring at a speed of 5000 r / min for 30 min; the mass ratio of nonylphenol polyoxyethylene ether to 1-amino-8-naphthol-4, 6-disulfonic acid was 1:2.5.

[0120] Comparative Example 4

[0121] A preparation method of a polyphosphoric acid-polymer composite modified asphalt, the preparation method comprising the following steps:

[0122] Different from Example 5 is that:

[0123] (4) benzoic anhydride was added to the asphalt obtained in step (3) to make the pH value of the reaction system 7.2, stirring at a speed of 5000 r / min for 10 min, then adding nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4, 6-disulfonic acid, and stirring at a speed of 5000 r / min for 30 min; the mass ratio of nonylphenol polyoxyethylene ether to 1-amino-8-naphthol-4, 6-disulfonic acid was 1:2.5.

[0124] Experimental Example 2

[0125] The properties of the polyphosphoric acid-polymer composite modified asphalt obtained in Example 5, Comparative Example 3 and Comparative Example 4 were detected, specifically including penetration (100 g, 25℃, 5 s), softening point, 5℃ ductility, rut factor high temperature index, creep stiffness modulus (-18℃), creep rate (-18℃), softening point difference (163℃), elastic recovery rate (25℃, 1h) and short-term aging (163℃, 5h) properties. Each test was carried out at least 3 times in parallel, and the average value was taken to obtain the test results as shown in Table 2.

[0126] The performance detection used the detection method and detection standard of JTG E20-2011 “Highway Engineering Asphalt and Asphalt Mixture Test Procedures”.

[0127] Table 2

[0128]

[0129] As shown in Table 2, the low-temperature performance of the modified asphalt is obviously improved by adding the anti-cracking agent including benzoic anhydride, nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4,6-disulfonic acid. As compared with Example 1-3 and Comparative Example 5, the penetration, softening point and ductility of the modified asphalt obtained in Example 3 are obviously higher than those of the modified asphalt obtained in Example 1-3. The increase in the penetration indicates that the modified asphalt provided in Example 5 is more easily flowable at low temperature, and exhibits better low-temperature ductility and anti-cracking performance. The higher the ductility of the asphalt at low temperature, the better the low-temperature performance of the modified asphalt. In the use of the asphalt, the low-temperature anti-cracking performance of the modified asphalt pavement is enhanced, and the low-temperature ductility and anti-cracking performance of the polyphosphoric acid modified asphalt are improved, and the pavement is less likely to be brittle and crusty and arch, so that the pavement can maintain flatness at low temperature.

[0130] Meanwhile, as compared with Comparative Examples 3 and 4 and Example 5, the benzoic anhydride can adjust the pH value during the preparation of the modified asphalt, and the pH value of the system is maintained at 5.5-7 before the addition of the nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4,6-disulfonic acid. The suitable acid-base environment is helpful to the reaction of the nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4,6-disulfonic acid with the asphalt, and is conducive to the stable formation of the multiphase composite structure, so as to ensure the low-temperature stability and anti-cracking performance of the modified asphalt.

[0131] Comparative Example 5

[0132] A preparation method of a polyphosphoric acid-polymer composite modified asphalt, the preparation method comprising the following steps:

[0133] The difference from Example 5 is that:

[0134] (4) 0.2 parts by weight of the anti-cracking agent is added, and the nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4,6-disulfonic acid are added into the asphalt obtained in step (3) and stirred at a speed of 5300 r / min for 25 min; the mass ratio of the nonylphenol polyoxyethylene ether to 1-amino-8-naphthol-4,6-disulfonic acid is 1:1.5.

[0135] Comparative Example 6

[0136] A preparation method of a polyphosphoric acid-polymer composite modified asphalt, the preparation method comprising the following steps:

[0137] The difference from Example 5 is that:

[0138] (4) 0.2 parts by weight of anti-cracking agent was added, benzoic anhydride was first added into the asphalt obtained in step (3) to make the pH value of the reaction system 6.5, stirring at a speed of 4000 r / min for 7 min, then 1-amino-8-naphthol-4, 6-disulfonic acid was added, and stirring was carried out at a speed of 5300 r / min for 25 min.

[0139] Comparative Example 7

[0140] A preparation method of a polyphosphoric acid-polymer composite modified asphalt, the preparation method comprising the following steps:

[0141] The difference from Example 5 is that:

[0142] (4) 0.2 parts by weight of anti-cracking agent was added, benzoic anhydride was first added into the asphalt obtained in step (3) to make the pH value of the reaction system 6.5, stirring at a speed of 4000 r / min for 7 min, then 1-amino-8-naphthol-4, 6-disulfonic acid was added, and stirring was carried out at a speed of 5300 r / min for 25 min.

[0143] Experimental Example 3

[0144] The properties of the polyphosphoric acid-polymer composite modified asphalt obtained in Example 5, Comparative Example 5-Comparative Example 7 were detected, specifically including penetration (100 g, 25℃, 5 s), softening point, 5℃ ductility, rut factor high temperature index, creep stiffness modulus (-18℃), creep rate (-18℃), softening point difference (163℃), elastic recovery rate (25℃, 1h) and short-term aging (163℃, 5h) properties. Each test was carried out at least 3 times in parallel, and the average value was taken to obtain the test results as shown in Table 3.

[0145] The performance detection used the detection method and detection standard of JTG E20-2011 “Highway Engineering Asphalt and Asphalt Mixture Test Procedures”.

[0146] Table 3

[0147]

[0148] From Table 3, it can be seen that by simultaneously adding nonylphenol polyoxyethylene ether, benzoic anhydride and 1-amino-8-naphthol-4,6-disulfonic acid, the low temperature performance of the modified asphalt is obviously improved, especially the penetration, softening point and elastic recovery rate, which indicates that the hydroxyl contained in nonylphenol polyoxyethylene ether can react with the surface active groups of asphalt, part of the amino, hydroxyl and sulfonic acid groups in 1-amino-8-naphthol-4,6-disulfonic acid react with the active sites on the surface of asphalt, further modify the asphalt, and the remaining 1-amino-8-naphthol-4,6-disulfonic acid is wrapped on the outer surface of the SEBS and PPA modified asphalt particles, a multi-phase composite structure is formed between the modifiers and the asphalt, when the modified asphalt is used in low temperature environment, the composite structures can buffer the stress generated by low temperature, thereby improving the low temperature performance of the modified asphalt and reducing the embrittlement and cracking of the modified asphalt due to temperature reduction.

[0149] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that; it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A polyphosphate-polymer composite modified asphalt, characterized in that, Raw materials comprising the following components by weight: 100 parts by weight of base bitumen, 0.5-3 parts by weight of polyphosphoric acid, 0.1-0.5 parts by weight of stabilizer, 2-5 parts by weight of bio-based plasticizer, 5-15 parts by weight of elastomer particles, 0.5-2 parts by weight of nano-reinforcing filler, 1-5 parts by weight of SEBS, 2-5 parts by weight of APAO, and 1-3 parts by weight of organomontmorillonite. The elastomer particles are selected from activated rubber powder, and the particle size of the activated rubber powder is 80-120 mesh. The asphalt also contains 0.05-0.4 parts by weight of an anti-cracking agent, which is obtained by mixing nonylphenol polyoxyethylene ether, benzoic anhydride and 1-amino-8-naphthol-4,6-disulfonic acid in a mass ratio of 1:0.55-4.5:1-2.

5. The preparation method of the polyphosphoric acid-polymer composite modified asphalt includes the following steps: (1) Heat the base asphalt to 160-170℃ according to the weight, add polyphosphoric acid to the base asphalt, and shear it at a high speed of 5000-5500r / min until it is evenly dispersed. After shearing, develop it at 165℃ for 30min. (2) Heat the asphalt obtained in step (1) to 170-180℃, add bio-based plasticizer and stabilizer according to the weight parts, and stir at a speed of 5000-5500r / min for 30min; (3) Add activated rubber powder, SEBS and APAO to the asphalt obtained in step (2) by weight, and maintain high-speed shearing at 180°C and 5000r / min for 1 hour; (4) Add benzoic anhydride to the asphalt obtained in step (3) by weight, stir at a speed of 3000-5000 r / min for 5-10 min, so that the pH value of the system is maintained at 5.5-7, then add nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4,6-disulfonic acid, and stir at a speed of 5000-5500 r / min for 20-30 min; (5) Add nano-reinforced filler and organic montmorillonite to the asphalt obtained in step (4), and shear at high speed for 2 hours at 180°C and 5000-5500 r / min. After shearing, develop at 170-180°C for 2 hours to obtain polyphosphate-polymer composite modified asphalt.

2. The polyphosphate-polymer composite modified asphalt according to claim 1, characterized in that, The polyphosphoric acid is an industrial-grade reagent with a purity of not less than 85% based on phosphorus pentoxide content.

3. The polyphosphate-polymer composite modified asphalt according to claim 1, characterized in that, The stabilizer is selected from sulfur or organosilicon coupling agents.

4. The polyphosphate-polymer composite modified asphalt according to claim 1, characterized in that, The bio-based plasticizer is selected from epoxidized soybean oil acrylate.

5. The polyphosphate-polymer composite modified asphalt according to claim 4, characterized in that, The epoxy value of the epoxidized soybean oil acrylate is 6.0%-6.5%.

6. The polyphosphate-polymer composite modified asphalt according to claim 1, characterized in that, The nano-reinforced filler includes at least one of graphene oxide and nano zinc oxide.

7. The polyphosphoric acid-polymer composite modified asphalt according to any one of claims 1-6, characterized in that, The base asphalt includes one or more of 70# base asphalt, 110# base asphalt, 130# base asphalt and 140# base asphalt.

8. A method for preparing polyphosphate-polymer composite modified asphalt, characterized in that, The method is used to prepare the modified asphalt according to any one of claims 1-7, and the preparation method includes the following steps: (1) Heat the base asphalt to 160-170℃ according to the weight, add polyphosphoric acid to the base asphalt, and shear it at a high speed of 5000-5500r / min until it is evenly dispersed. After shearing, develop it at 165℃ for 30min. (2) Heat the asphalt obtained in step (1) to 170-180℃, add bio-based plasticizer and stabilizer according to the weight parts, and stir at a speed of 5000-5500r / min for 30min; (3) Add activated rubber powder, SEBS and APAO to the asphalt obtained in step (2) by weight, and maintain high-speed shearing at 180°C and 5000r / min for 1 hour; (4) Add benzoic anhydride to the asphalt obtained in step (3) by weight, stir at a speed of 3000-5000 r / min for 5-10 min, so that the pH value of the system is maintained at 5.5-7, then add nonylphenol polyoxyethylene ether and 1-amino-8-naphthol-4,6-disulfonic acid, and stir at a speed of 5000-5500 r / min for 20-30 min; (5) Add nano-reinforced filler and organic montmorillonite to the asphalt obtained in step (4), and shear at high speed for 2 hours at 180°C and 5000-5500 r / min. After shearing, develop at 170-180°C for 2 hours to obtain polyphosphate-polymer composite modified asphalt.

Images