Modified asphalt and preparation method thereof

Abstract

The invention discloses modified asphalt and a preparation method thereof. The modified asphalt is prepared from the following components in parts by weight: 100 parts of matrix asphalt, 0.5 to 4 parts of solubilizer, 4 to 6 parts of polymer modifier, 4 to 8 parts of high-viscosity modifier, 0.5 to 1 part of modified polyamide fiber, 0.3 to 0.5 part of initiator and 0.2 to 0.4 part of stabilizer. The modified asphalt is high-viscosity high-elasticity modified asphalt, the low-temperature PG grading of the asphalt can be improved, and the low-temperature crack resistance of an asphalt mixture is improved.

Description

Technical Field

[0001] This invention relates to the field of modified asphalt, specifically to a high-viscosity, high-elasticity modified asphalt and its preparation method. Background Technology

[0002] Asphalt pavement is the main structural form of road surfaces in China. Under the influence of factors such as increased traffic load, longer service life, and complex service conditions and climate, pavement will experience problems such as aging, loosening, cracking, and deformation, thus requiring the replacement of asphalt pavement. Traditional milling and resurfacing methods are not suitable for asphalt pavements without structural defects. However, ultra-thin overlay, as a new preventive maintenance technology, uses high-viscosity and high-elasticity modified asphalt as a binder, which can significantly improve the strength, water damage resistance, loosening resistance, and high-temperature deformation resistance of the mixture, all of which are significantly better than ordinary modified asphalt mixtures.

[0003] Current methods for preparing high-viscosity, high-elasticity modified asphalt mainly involve adding high-viscosity modifiers, thermoplastic elastomers, and rubber powder. Among these, Japanese TPS is the most commonly used high-viscosity modifier, but its high cost limits its application. High-content styrene-butadiene-styrene block copolymer (SBS) can also significantly improve asphalt performance and can be used to prepare high-viscosity, high-elasticity modified asphalt; however, high-content SBS has insufficient compatibility with asphalt and is difficult to disperse uniformly in the asphalt. Furthermore, SBS / rubber powder composite modification can improve the high-temperature performance of high-viscosity, high-elasticity modified asphalt, but rubber powder-modified asphalt requires higher processing temperatures and has a shorter storage time. Practical engineering applications of high-viscosity, high-elasticity modified asphalt show that it can significantly improve the high-temperature performance and water stability of asphalt mixtures, extending their service life, but it has certain deficiencies in low-temperature crack resistance.

[0004] CN110452550A discloses a method for preparing high-viscosity and high-elasticity modified asphalt using SBS and waste rubber powder. First, styrene-butadiene-styrene block copolymer is mixed and modified with base asphalt, and then waste rubber powder is added for further mixing and modification. This yields modified asphalt with good mechanical properties and storage stability. However, the rubber powder modified asphalt has a high processing temperature, is difficult to construct, and has a short storage time.

[0005] CN115895286A discloses a high-viscosity, high-elasticity modified asphalt and its preparation method. The method includes the following components: residual oil, a co-solvent, a polymer modifier, a high-viscosity modifier, and a stabilizer. The polymer modifier is a block copolymer of styrene-butadiene-styrene, and the high-viscosity modifier is a polyolefin elastomer. The resulting high-viscosity, high-elasticity modified asphalt does not contain any waste rubber powder, but its low-temperature crack resistance is not clearly defined.

[0006] Therefore, developing a high-viscosity, high-elasticity modified asphalt with excellent durability, high-temperature stability, and low-temperature crack resistance, suitable for the paving needs of high-quality, multi-functional pavements, is of great significance to road engineering. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a modified asphalt and its preparation method. This modified asphalt is a high-viscosity, high-elasticity modified asphalt, and it can improve the low-temperature PG grading of asphalt and enhance the low-temperature crack resistance of asphalt mixtures.

[0008] The first aspect of this invention provides a modified asphalt, comprising, by weight:

[0009]

[0010] Furthermore, the base asphalt is No. 70 road asphalt and / or No. 90 road asphalt, preferably No. 70 Grade A road asphalt.

[0011] Furthermore, the four components of the base asphalt are distributed as follows: asphaltene 10-14 wt%, resin 18-20 wt%, saturated components 16-24 wt%, and aromatic components 45-55 wt%.

[0012] Further, the solubilizer is an aromatic extractive oil, preferably furfural extractive oil. The aromatic extractive oil has a flash point of 230℃~250℃, and by mass content, a wax content of ≤2%, preferably 1.0%~1.5%, and an aromatic hydrocarbon content of ≥50%, preferably 50.0%~65.0%.

[0013] Further, the polymer modifier is SBS (styrene-butadiene-styrene triblock copolymer). The SBS is preferably linear SBS. The molecular weight of the SBS is 100,000 to 150,000.

[0014] Furthermore, the high-viscosity modifier is one or more of the following: p-tert-octylphenol resin, 138 rosin glycerol ester, 145 rosin pentaerythritol ester, C5 resin, and C5 / C9 copolymer resin.

[0015] Furthermore, the initiator is one or more of dialkyl peroxides such as dicumyl peroxide, di(tert-butylperoxyisopropyl)benzene, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane.

[0016] Furthermore, the stabilizer is sulfur powder, which may be one or more of sublimated sulfur, precipitated sulfur, or refined sulfur.

[0017] Further, the modified polyamide fiber, by weight, comprises:

[0018] 3-5 parts of polyamide fiber;

[0019] 1-2 parts of nano-montmorillonite;

[0020] 1-2 parts of unsaturated polyester;

[0021] 0.5 to 1 part of coupling agent.

[0022] Furthermore, the polyamide fiber is an aliphatic polyamide fiber, preferably, the polyamide fiber has a length of 3-6 mm and an aspect ratio of 100-150.

[0023] Furthermore, the average particle size of the nano-montmorillonite is 100–200 nm. The nano-montmorillonite is one or more of sodium-based montmorillonite, calcium-based montmorillonite, and magnesium-based montmorillonite.

[0024] Furthermore, the unsaturated polyester is one or more of 198# unsaturated polyester resin, 199# unsaturated polyester resin, and 191# unsaturated polyester resin.

[0025] Further, the coupling agent is one or more selected from vinyltriethoxysilane, γ-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidyl etheroxypropyltrimethylsilane, and γ-methacryloyloxypropyltrimethoxysilane.

[0026] Furthermore, the method for preparing the modified polyamide fiber includes:

[0027] (a) Mix nano-montmorillonite, coupling agent, and water, then add polyamide fiber, react, filter, and dry to obtain composite polyamide fiber;

[0028] (b) The composite polyamide fiber obtained in step (a) is mixed with unsaturated polyester, stirred, and dried to obtain modified polyamide fiber.

[0029] Further, in step (a), the mass ratio of the nano-montmorillonite to water is 1:20 to 1:30. The water is preferably deionized water.

[0030] Further, in step (a), the reaction conditions include: a reaction pressure of 0.2–0.5 MPa, a reaction time of 60–80 min, a reaction temperature of 40–60 °C, and the reaction is carried out under a nitrogen atmosphere.

[0031] Further, in step (a), the drying conditions are: temperature of 100-120°C and time of 2.5-3 hours.

[0032] Further, in step (b), the stirring time is 1 to 1.5 hours, and the stirring rate is 100 to 250 r / min.

[0033] Further, in step (b), the drying conditions are: a temperature of 70–90°C and a time of 2.5–3 hours.

[0034] A second aspect of the present invention provides a method for preparing the above-mentioned modified asphalt, comprising:

[0035] (1) Mix the solubilizer and the base asphalt, stir, and obtain blended asphalt;

[0036] (2) Mix the polymer modifier, high viscosity modifier and the blended asphalt obtained in step (1), heat to swell, and shear to obtain precast asphalt;

[0037] (3) Mix the precast asphalt obtained in step (2) with modified polyamide fiber, and cut it to obtain the asphalt to be developed;

[0038] (4) Mix the initiator, stabilizer and the asphalt to be developed in step (3), and shear to obtain modified asphalt.

[0039] Further, in step (1), the base asphalt is first heated to 140-150°C, and then a solubilizer is added and stirred.

[0040] Further, in step (1), the stirring rate is 200-400 r / min, and the stirring time is 0.5-1.5 hours.

[0041] Furthermore, in step (2), the mixing can be carried out by mechanical stirring until the mixture is uniform.

[0042] Furthermore, in step (2), the heating and swelling can be carried out in an oven. The heating and swelling temperature is 170-180°C, preferably 170-180°C, and the time is 0.5-1h.

[0043] Further, in step (2), the shearing rate is 4000-5500 r / min, and the shearing time is 0.5-1.5 hours.

[0044] Further, in step (3), the precast asphalt is first heated to 170-180°C, and then modified polyamide fibers are added and mixed.

[0045] Further, in step (3), the shearing conditions are: the shearing rate is 1500-2000 r / min, and the shearing time is 0.5-1.5 hours.

[0046] Further, in step (4), the asphalt to be developed is first heated to 185-195℃, and an initiator and part of the stabilizer (accounting for 30%-50% of the total stabilizer mass) are added. It is sheared at a speed of 1500-2000 r / min for 1.0-1.5 h, and then the remaining part of the stabilizer (accounting for 50%-70% of the total stabilizer mass) is added. Finally, it is developed at 185-195℃ for 30-40 min to obtain modified asphalt.

[0047] Compared with the prior art, the present invention has the following technical effects:

[0048] (1) Through the synergistic combination of its components, the modified asphalt of this invention achieves a final product with a dynamic viscosity of over 58,000 Pa·s at 60°C, a softening point greater than 90°C, an elastic recovery greater than 98%, and a low-temperature PG grade of -24°C. In other words, the modified asphalt of this invention possesses high viscosity and high elasticity, as well as excellent high-temperature stability and low-temperature crack resistance.

[0049] (2) Due to the abundance of hydroxyl groups on the surface of polyamide fibers, they are prone to self-polymerization, have high polarity, and a relatively smooth surface, resulting in poor dispersion and compatibility in asphalt and weak interfacial bonding. However, the modified polyamide fibers prepared by the present invention using nano-montmorillonite, coupling agents, and unsaturated polyester not only retain the characteristics of high elastic modulus and strong elongation of polyamide fibers, improving the cohesiveness and tensile strength of asphalt, but also significantly improve the low-temperature toughening and crack resistance of asphalt mixtures. At the same time, under the bridging effect of the coupling agent, hydroxymethyl groups undergo a condensation reaction with the amide groups of polyamide fibers, and silanol hydrogen atoms form hydrogen bonds with the silicon-oxygen tetrahedral oxygen atoms in the interlayer of nano-montmorillonite. The other side contains groups with polarity similar to that of unsaturated polyester molecules, thus covering the fiber surface and improving the compatibility of the two phases. In addition, the polyamide fibers form a three-dimensional network structure with nano-montmorillonite and unsaturated polyester, which helps to improve the mechanical properties of the composite material. Nano-montmorillonite has a special layered structure that can fill the gaps between asphalt molecules, forming a strong structural asphalt interface layer, making the asphalt more compact and stable, and improving the storage stability and anti-aging properties of the system.

[0050] (3) In this invention, the polystyrene segment in the polymer modifier can, on the one hand, form a three-dimensional network structure dispersed in the asphalt under the crosslinking action of the stabilizer, transfer and consume stress, and improve the strength of the modified asphalt; on the other hand, under the action of the initiator, it can co-crosslink with the unsaturated polyester in the modified fiber to form a crosslinked network, making the network formed by the composite material more compact, and improving the viscosity and mechanical properties of the asphalt; the creep recovery ability of the polybutadiene segment is strong, which can simultaneously improve the elasticity of the asphalt, thereby improving the high-temperature rutting resistance and low-temperature crack resistance of the modified asphalt; the compatibilizer is rich in aromatic components, which can improve the compatibility between the polymer modifier and the asphalt, reduce the occurrence of segregation, and improve the storage stability of the modified asphalt; the high viscosity modifier contains hydroxyl, hydroxymethyl, carboxyl, ester bonds, etc., which can easily form a hydrogen bond interpenetrating network structure with the modified polyamide fiber during the asphalt mixing process. The alkane groups contained in the branch chain have good compatibility with the asphalt and strong binding effect. The diffusion and migration of the asphalt are worse, the mutual entanglement between molecules is enhanced, and the entanglement strength is increased, resulting in increased bonding strength, which can significantly improve the viscosity of the asphalt.

[0051] (4) The high viscosity and high elasticity modified asphalt preparation method provided by the present invention is simple and low cost. It can be applied to the paving needs of multi-functional pavements such as drainage pavement, bridge deck paving, and thin-layer overlay maintenance. It not only has good high temperature stability, elastic deformation and anti-aging performance, but also significantly enhances the low temperature and fatigue crack resistance of the mixture, and improves the pavement performance and service life. Detailed Implementation

[0052] The technical solution of the present invention will be described in detail below with reference to the embodiments, but the present invention is not limited to the following embodiments. In the present invention, wt% is a mass fraction.

[0053] In this invention, the relevant indicators of modified asphalt are tested according to the test methods specified in the Test Procedure for Asphalt and Asphalt Mixtures for Highway Engineering (JTG E20-2011), and the low-temperature performance of modified asphalt is tested according to the SHRP Asphalt Road Performance Specification.

[0054] Example 1

[0055] In this embodiment, the modified asphalt is made from the following raw materials in parts by weight: 100 parts of Qilu 70A asphalt (10.72wt% asphaltene, 19.92wt% resin, 17.87wt% saturated content, and 51.49wt% aromatic content), 2.5 parts of furfural extract oil (flash point 237℃, wax content 1.5%, aromatic content 52% by mass), 4 parts of SBS modifier (Baling Petrochemical YH-791H linear SBS, molecular weight 100,000), 8 parts of high viscosity modifier (p-tert-octylphenol resin: 138 rosin glycerol ester: C5 resin weight ratio 1:2:1), 1 part of modified polyamide fiber (polyamide fiber: sodium montmorillonite: 198# unsaturated polyester resin: γ-aminopropyltrimethoxysilane weight ratio 5:2:2:1), 0.5 parts of initiator (dicumyl peroxide), and 0.3 parts of refined sulfur powder.

[0056] The modified polyester fiber was prepared as follows: A suspension was prepared by mixing 2 parts sodium montmorillonite (average particle size 100 nm), 1 part γ-aminopropyltrimethoxysilane, and 50 parts deionized water. 5 parts polyamide fiber (fiber length 5 mm, aspect ratio approximately 135) were added to the suspension. The mixture was pressurized with 0.4 MPa nitrogen gas and immersed at 40°C for 80 min. After filtration, the mixture was placed in an oven at 105°C for 3 h to obtain composite polyamide fiber. The obtained composite polyamide fiber was then mixed with 2 parts 198# unsaturated polyester resin by stirring at 200 r / min for 1 h. The mixture was then placed in an oven at 80°C for 3 h. Finally, it was removed and stored in a sealed container for later use, yielding the modified polyamide fiber.

[0057] The preparation of modified asphalt shall be carried out according to the following steps:

[0058] (1) First, heat 100 parts of Qilu 70A asphalt to 140℃, then add 2.5 parts of furfural extract oil and mix at 200r / min for 1h to obtain blended asphalt;

[0059] (2) Mix 4 parts of YH-791H linear SBS modifier and 8 parts of high viscosity modifier with blended asphalt, heat and swell in an oven at 180°C for 1 hour, and then shear at 4500 r / min for 1 hour to obtain precast asphalt.

[0060] (3) Heat the precast asphalt to 180°C, then add 1 part of modified polyamide fiber and shear at 1500 r / min for 0.5 h to obtain the asphalt to be developed;

[0061] (4) Heat the asphalt to be developed to 185°C, add 0.5 parts of diisopropylbenzene peroxide and 0.15 parts of refined sulfur powder, stir and mix at 1500-2000 r / min for 1 h, add 0.15 parts of refined sulfur powder, and finally develop at 185°C for 40 min to obtain modified asphalt-1.

[0062] Example 2

[0063] In this embodiment, the modified asphalt is made from the following raw materials in parts by weight: 100 parts of Qilu 70A asphalt (10.72wt% asphaltene, 19.92wt% resin, 17.87wt% saturated content, and 51.49wt% aromatic content), 2.2 parts of furfural extract oil (flash point 237℃, wax content 1.5%, aromatic content 52% by mass), 5 parts of SBS modifier (Baling Petrochemical YH-791H linear SBS, molecular weight 100,000), 6 parts of high viscosity modifier (1:2:1 ratio of p-tert-octylphenol resin: 138 rosin glycerol ester: C5 resin), 0.8 parts of modified polyamide fiber (5:2:2:1 ratio of polyamide fiber: sodium montmorillonite: 198# unsaturated polyester resin: γ-aminopropyltrimethoxysilane), 0.4 parts of initiator (diisopropylbenzene peroxide), and 0.4 parts of refined sulfur powder.

[0064] The modified polyester fiber was prepared as follows: A suspension was prepared by mixing 2 parts sodium montmorillonite (average particle size 100 nm), 1 part γ-aminopropyltrimethoxysilane, and 50 parts deionized water. 5 parts polyamide fiber (fiber length 5 mm, aspect ratio approximately 135) were added to the solution. Nitrogen gas at 0.4 MPa was introduced to pressurize the solution, and the mixture was immersed at 40°C for 80 min. The mixture was then filtered and placed in an oven at 105°C for 3 h to obtain composite polyamide fiber. The obtained composite polyamide fiber was then mixed with 2 parts 198# unsaturated polyester resin by stirring at 200 r / min for 1 h. The mixture was then placed in an oven at 80°C for 3 h, removed, and stored in a sealed container for later use, thus obtaining the modified polyamide fiber.

[0065] The preparation of modified asphalt shall be carried out according to the following steps:

[0066] (1) First, heat 100 parts of Qilu 70A asphalt to 140℃, then add 2.2 parts of furfural extract oil and mix at 200r / min for 1h to obtain blended asphalt;

[0067] (2) Mix 5 parts of YH-791H linear SBS modifier and 6 parts of high viscosity modifier with blended asphalt, heat and swell in an oven at 180°C for 1 hour, and then shear at 4500 r / min for 1 hour to obtain precast asphalt.

[0068] (3) Heat the precast asphalt to 180°C, then add 0.8 parts of modified polyamide fiber and shear at 1500 r / min for 0.5 h to obtain the asphalt to be developed;

[0069] (4) Heat the asphalt to be developed to 185°C, add 0.4 parts of diisopropylbenzene peroxide and 0.2 parts of refined sulfur powder, stir and mix at 1500-2000 r / min for 1 h, add 0.2 parts of refined sulfur powder, and finally develop at 185°C for 40 min to obtain modified asphalt-2.

[0070] Example 3

[0071] In this embodiment, the modified asphalt is made from the following raw materials in parts by weight: 100 parts of Qilu 70A asphalt (10.72wt% asphaltene, 19.92wt% resin, 17.87wt% saturated content, and 51.49wt% aromatic content), 2 parts of furfural extract oil (flash point 237℃, wax content 1.5% and aromatic content 52% by mass), 6 parts of SBS modifier (Baling Petrochemical YH-791H linear SBS with a molecular weight of 100,000), 4 parts of high viscosity modifier (1:2:1 ratio of p-tert-octylphenol resin, 138 rosin glycerol ester, and C5 resin), 1 part of modified polyamide fiber (5:2:2:1 ratio of polyamide fiber, sodium montmorillonite, 198# unsaturated polyester resin, and γ-aminopropyltrimethoxysilane), 0.5 parts of initiator (diisopropylbenzene peroxide), and 0.5 parts of refined sulfur powder.

[0072] The modified polyester fiber was prepared as follows: A suspension was prepared by mixing 2 parts sodium montmorillonite (average particle size 100 nm), 1 part γ-aminopropyltrimethoxysilane, and 50 parts deionized water. 5 parts polyamide fiber (fiber length 5 mm, aspect ratio approximately 135) were added to the solution. Nitrogen gas at 0.4 MPa was introduced to pressurize the solution, and the mixture was immersed at 40°C for 80 min. The mixture was then filtered and placed in an oven at 105°C for 3 h to obtain composite polyamide fiber. The obtained composite polyamide fiber was then mixed with 2 parts 198# unsaturated polyester resin by stirring at 200 r / min for 1 h. The mixture was then placed in an oven at 80°C for 3 h, removed, and stored in a sealed container for later use, thus obtaining the modified polyamide fiber.

[0073] The preparation of modified asphalt shall be carried out according to the following steps:

[0074] (1) First, heat 100 parts of Qilu 70A asphalt to 140℃, then add 2 parts of furfural extract oil at 200r / min and mix for 1h to obtain blended asphalt;

[0075] (2) Mix 6 parts of YH-791H linear SBS modifier, 4 parts of high viscosity modifier with blended asphalt, heat and swell in an oven at 180°C for 1 hour, and then shear at 4500 r / min for 1 hour to obtain precast asphalt.

[0076] (3) Heat the precast asphalt to 180°C, then add 1 part of modified polyamide fiber and shear at 1500 r / min for 0.5 h to obtain the asphalt to be developed;

[0077] (4) Heat the asphalt to be developed to 185°C, add 0.5 parts of diisopropylbenzene peroxide and 0.25 parts of refined sulfur powder, stir and mix at 1500-2000 r / min for 1 h, add 0.25 parts of refined sulfur powder, and finally develop at 185°C for 40 min to obtain modified asphalt-3.

[0078] Example 4

[0079] In this embodiment, the modified asphalt is made from the following raw materials in parts by weight: 100 parts of Qilu 70A asphalt (10.72 wt% asphaltene, 19.92 wt% resin, 17.87 wt% saturated content, and 51.49 wt% aromatic content), 2.2 parts of furfural extract oil (flash point 237℃, wax content 1.5%, aromatic content 52% by mass), and 5 parts of SBS modifier (Baling Petrochemical YH-791H linear type). SBS (molecular weight 100,000), 6 parts high-viscosity modifier (p-tert-octylphenol resin: 145 rosin pentaerythritol ester: C5 / C9 copolymer resin 1:2:1), 0.5 parts modified polyamide fiber (polyamide fiber: calcium montmorillonite: 199# unsaturated polyester resin: 3-aminopropyltrimethoxysilane 4:2:2:1), 0.3 parts initiator (di-tert-butyl peroxide isopropylbenzene), and 0.4 parts refined sulfur powder.

[0080] The modified polyester fiber was prepared as follows: A suspension was prepared by mixing 2 parts of calcium-based montmorillonite (average particle size 200 nm), 1 part of 3-aminopropyltrimethoxysilane, and 60 parts of deionized water. 4 parts of polyamide fiber (fiber length 4 mm, aspect ratio approximately 150) were added to the suspension. The solution was pressurized with 0.3 MPa nitrogen gas and immersed at 60°C for 60 min. The mixture was then filtered and placed in an oven at 120°C for 3 h to obtain composite polyamide fiber. The obtained composite polyamide fiber was then mixed with 2 parts of 199# unsaturated polyester resin by stirring at 150 r / min for 1.5 h. The mixture was then placed in an oven at 90°C for 2.5 h, removed, and stored in a sealed container for later use to obtain the modified polyamide fiber.

[0081] The preparation of the above-mentioned modified asphalt is carried out according to the following steps:

[0082] (1) First, heat 100 parts of Qilu 70A asphalt to 145℃, then add 2.2 parts of furfural extract oil and mix at 300r / min for 0.8h to obtain blended asphalt;

[0083] (2) Mix 5 parts of YH-791H linear SBS modifier and 6 parts of high viscosity modifier with blended asphalt, heat and swell at 175℃ in an oven for 1.5h, and then shear at 4500r / min for 1h to obtain precast asphalt.

[0084] (3) Heat the precast asphalt to 175°C, then add 0.5 parts of modified polyamide fiber and shear at 1800 r / min for 0.5 h to obtain the asphalt to be developed;

[0085] (4) Heat the asphalt to be developed to 190°C, add 0.3 parts of di-tert-butyl peroxide isopropylbenzene and 0.2 parts of refined sulfur powder, stir and mix at 1500-2000 r / min for 1 h, add 0.2 parts of refined sulfur powder, and finally develop at 190°C for 40 min to obtain modified asphalt-4.

[0086] Example 5

[0087] In this embodiment, the modified asphalt was made from the following raw materials in parts by weight: 100 parts of Qilu 70A asphalt (10.72 wt% asphaltene, 19.92 wt% resin, 17.87 wt% saturated content, and 51.49 wt% aromatic content), 2.2 parts of furfural extract oil (flash point 237℃, wax content 1.5%, aromatic content 52% by mass), and 5 parts of SBS modifier (Baling Petrochemical YH-791H linear SBS, molecular weight...). 100,000), 6 parts of high-viscosity modifier (1:2:1 of p-tert-octylphenol resin, 145 rosin pentaerythritol ester, and C5 / C9 copolymer resin), 0.8 parts of modified polyamide fiber (5:2:2:1 of polyamide fiber, magnesium montmorillonite, 191# unsaturated polyester resin, and 3-glycidyl etheroxypropyltrimethylsilane), 0.4 parts of initiator (2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane), and 0.4 parts of refined sulfur powder.

[0088] The modified polyester fiber was prepared as follows: A suspension was prepared by mixing 2 parts magnesium-based montmorillonite (average particle size 150 nm), 1 part 3-glycidyl etheroxypropyltrimethylsilane, and 60 parts deionized water. 5 parts polyamide fiber (fiber length 6 mm, aspect ratio approximately 130) were added to the solution. The solution was pressurized with 0.3 MPa nitrogen gas and immersed at 60°C for 80 min. The mixture was then filtered and placed in an oven at 120°C for 3 h to obtain composite polyamide fiber. The obtained composite polyamide fiber was then mixed with 2 parts 191# unsaturated polyester resin by stirring at 250 r / min for 1.5 h. The mixture was then placed in an oven at 80°C for 3 h, removed, and stored in a sealed container for later use, thus obtaining the modified polyamide fiber.

[0089] The preparation of modified asphalt shall be carried out according to the following steps:

[0090] (1) First, heat 100 parts of Qilu 70A asphalt to 150℃, then add 2.2 parts of furfural extract oil and mix at 200r / min for 1.5h to obtain blended asphalt;

[0091] (2) Mix 5 parts of YH-791H linear SBS modifier, 6 parts of high viscosity modifier with blended asphalt, heat and swell at 170℃ in an oven for 1.5h, and then shear at 4500r / min for 1h to obtain precast asphalt.

[0092] (3) Heat the precast asphalt to 180°C, then add 0.8 parts of modified polyamide fiber and shear at 2000 r / min for 0.5 h to obtain the asphalt to be developed;

[0093] (4) Heat the asphalt to be developed to 190℃, add 0.4 parts of per-2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and 0.2 parts of refined sulfur powder, stir and mix at 1500-2000 r / min for 1 h, then add 0.2 parts of refined sulfur powder, and finally develop at 190℃ for 40 min to obtain modified asphalt-5.

[0094] Comparative Example 1

[0095] In this example, the modified asphalt is made from the following raw materials in parts by weight: 100 parts of Qilu 70A asphalt (10.72wt% asphaltene, 19.92wt% resin, 17.87wt% saturated content, and 51.49wt% aromatic content), 2.5 parts of furfural extract oil (flash point 237℃, wax content 1.5%, aromatic content 52% by mass), 4 parts of SBS modifier (Baling Petrochemical YH-791H linear SBS, molecular weight 100,000), 8 parts of high viscosity modifier (1:2:1 ratio of p-tert-octylphenol resin: 138 rosin glycerol ester: C5 resin), 1 part of polyamide fiber, 0.5 parts of initiator (diisopropylbenzene peroxide), and 0.3 parts of refined sulfur powder.

[0096] The preparation of modified asphalt shall be carried out according to the following steps:

[0097] (1) First, heat 100 parts of Qilu 70A asphalt to 140℃, then add 2.5 parts of furfural extract oil and mix at 200r / min for 1h to obtain blended asphalt;

[0098] (2) Mix 4 parts of YH-791H linear SBS modifier and 8 parts of high viscosity modifier with blended asphalt, heat and swell in an oven at 180°C for 1 hour, and then shear at 4500 r / min for 1 hour to obtain precast asphalt.

[0099] (3) Heat the precast asphalt to 180°C, then add 1 part of polyamide fiber and shear at 1500 r / min for 0.5 h to obtain the asphalt to be developed;

[0100] (4) Heat the asphalt to be developed to 185°C, add 0.5 parts of diisopropylbenzene peroxide and 0.15 parts of refined sulfur powder, stir and mix at 1500-2000 r / min for 1 h, add 0.15 parts of refined sulfur powder, and finally develop at 185°C for 40 min to obtain modified asphalt-6.

[0101] Comparative Example 2

[0102] In this example, the modified asphalt is made from the following raw materials in parts by weight: 100 parts of Qilu 70A asphalt (10.72wt% asphaltene, 19.92wt% resin, 17.87wt% saturated content, and 51.49wt% aromatic content), 2.5 parts of furfural extract oil (flash point 237℃, wax content 1.5% and aromatic content 52% by mass), 4 parts of SBS modifier (Baling Petrochemical YH-791H linear SBS with a molecular weight of 100,000), 1 part of modified polyamide fiber (polyamide fiber: sodium montmorillonite: 198# unsaturated polyester resin: γ-aminopropyltrimethoxysilane in a ratio of 5:2:2:1), 0.5 parts of initiator (dicumyl peroxide), and 0.3 parts of refined sulfur powder.

[0103] The modified polyester fiber was prepared as follows: A suspension was prepared by mixing 2 parts sodium montmorillonite (average particle size 100 nm), 1 part γ-aminopropyltrimethoxysilane, and 50 parts deionized water. 5 parts polyamide fiber (fiber length 5 mm, aspect ratio approximately 135) were added to the suspension. Nitrogen gas at 0.4 MPa was introduced to pressurize the solution, and the fiber was soaked at 40°C for 80 min. The mixture was then filtered and placed in an oven at 105°C for 3 h to obtain composite polyamide fiber. The obtained composite polyamide fiber was then mixed with 2 parts 198# unsaturated polyester resin by stirring at 200 r / min for 1 h. The mixture was then placed in an oven at 80°C for 3 h, removed, and stored in a sealed container for later use, thus obtaining the modified polyamide fiber.

[0104] The preparation of the above-mentioned modified asphalt is carried out according to the following steps:

[0105] (1) First, heat 100 parts of Qilu 70A asphalt to 140℃, then add 2.5 parts of furfural extract oil and mix at 200r / min for 1h to obtain blended asphalt;

[0106] (2) Mix 4 parts of YH-791H linear SBS modifier with blended asphalt, heat and swell in an oven at 180°C for 1 hour, and then shear at 4500 r / min for 1 hour to obtain precast asphalt.

[0107] (3) Heat the precast asphalt to 180°C, then add 1 part of modified polyamide fiber and shear at 1500 r / min for 0.5 h to obtain the asphalt to be developed;

[0108] (4) Heat the asphalt to be developed to 185°C, add 0.5 parts of diisopropylbenzene peroxide and 0.15 parts of refined sulfur powder, stir and mix at 1500-2000 r / min for 1 h, add 0.15 parts of refined sulfur powder, and finally develop at 185°C for 40 min to obtain modified asphalt-7.

[0109] Comparative Example 3

[0110] In this example, the modified asphalt is made from the following raw materials in parts by weight: 100 parts of Qilu 70A asphalt (10.72 wt% asphaltene, 19.92 wt% resin, 17.87 wt% saturated content, and 51.49 wt% aromatic content), 2.5 parts of furfural extract oil (flash point 237℃, wax content 1.5%, aromatic content 52% by mass), 8 parts of high viscosity modifier (1:2:1 of p-tert-octylphenol resin, 138 rosin glycerol ester, and C5 resin), 1 part of modified polyamide fiber (5:2:2:1 of polyamide fiber, sodium montmorillonite, 198# unsaturated polyester resin, and γ-aminopropyltrimethoxysilane), and 0.5 parts of initiator (diisopropylbenzene peroxide).

[0111] The modified polyester fiber was prepared as follows: A suspension was prepared by mixing 2 parts sodium montmorillonite (average particle size 100 nm), 1 part γ-aminopropyltrimethoxysilane, and 50 parts deionized water. 5 parts polyamide fiber (fiber length 5 mm, aspect ratio approximately 135) were added to the suspension. Nitrogen gas at 0.4 MPa was introduced to pressurize the solution, and the fiber was soaked at 40°C for 80 min. The mixture was then filtered and placed in an oven at 105°C for 3 h to obtain composite polyamide fiber. The obtained composite polyamide fiber was then mixed with 2 parts 198# unsaturated polyester resin by stirring at 200 r / min for 1 h. The mixture was then placed in an oven at 80°C for 3 h, removed, and stored in a sealed container for later use, thus obtaining the modified polyamide fiber.

[0112] The preparation of modified asphalt shall be carried out according to the following steps:

[0113] (1) First, heat 100 parts of Qilu 70A asphalt to 140℃, then add 2.5 parts of furfural extract oil and mix at 200r / min for 1h to obtain blended asphalt;

[0114] (2) Mix 8 parts of high viscosity modifier with blended asphalt, heat and swell in an oven at 180°C for 1 hour, and then shear at 4500 r / min for 1 hour to obtain precast asphalt.

[0115] (3) Heat the precast asphalt to 180°C, then add 1 part of modified polyamide fiber and shear at 1500 r / min for 0.5 h to obtain the asphalt to be developed;

[0116] (4) Heat the asphalt to be developed to 185℃, add 0.5 parts of diisopropylbenzene peroxide, and stir and mix at a speed of 1500~2000r / min for 1h to obtain modified asphalt-8.

[0117] The technical indicators of the high-viscosity and high-elasticity modified asphalt prepared in the above embodiments and comparative examples were tested in accordance with (JTGE20-2011) "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering". The results are shown in Table 1.

[0118] Table 1. Performance data of the modified asphalt prepared in Examples 1-5 and Comparative Examples 1-3.

[0119]

[0120] As can be seen from the results in Table 1, the modified asphalts prepared in Examples 1 to 5 have a dynamic viscosity greater than 580,000 Pa·s at 60℃, a softening point greater than 90℃, an elastic recovery greater than 98%, a ductility greater than 30 cm at 5℃, and a segregation softening point difference less than 2.5℃, all of which meet the specifications. This indicates that the high-viscosity and high-elasticity modified asphalt of the present invention has excellent high-temperature performance, viscoelastic properties, storage stability, and ease of construction.

[0121] Table 2. Low-temperature performance data of the modified asphalts prepared in Examples 1-5 and Comparative Examples 1-3.

[0122]

[0123] As can be seen from the results in Table 2, the modified asphalt prepared in Examples 1 to 5 all meet the requirements of creep rate m greater than 0.3, creep stiffness S less than 300 MPa, and low-temperature PG classification of -24℃ at -18℃ and -24℃.

Claims

1. A modified asphalt, characterized in that, By weight, it includes:

2. The modified asphalt according to claim 1, characterized in that, The base asphalt is No. 70 road asphalt and / or No. 90 road asphalt, preferably No. 70 Grade A road asphalt; And / or, the four components of the base bitumen are distributed as follows: asphaltene 10-14 wt%, resin 18-20 wt%, saturated components 16-24 wt%, and aromatic components 45-55 wt%.

3. The modified asphalt according to claim 1, characterized in that, The solubilizer is a rich aromatic extract oil, preferably furfural extract oil; the rich aromatic extract oil has a flash point of 230℃~250℃, and by mass content, the wax content is ≤2%, preferably 1.0%~1.5%, and the aromatic content is ≥50%, preferably 50.0%~65.0%. And / or, the polymer modifier is SBS, and the molecular weight of the SBS is 100,000 to 150,000; And / or, the high viscosity modifier is one or more of p-tert-octylphenol resin, 138 rosin glycerol ester, 145 rosin pentaerythritol ester, C5 resin, and C5 / C9 copolymer resin. And / or, the initiator is one or more of dicumyl peroxide, di(tert-butylperoxide)benzene and 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane; And / or, the stabilizer is sulfur powder, preferably one or more of sublimed sulfur, precipitated sulfur or refined sulfur.

4. The modified asphalt according to claim 1, characterized in that, The modified polyamide fiber, by weight, comprises: 3-5 parts of polyamide fiber; 1-2 parts of nano-montmorillonite; 1-2 parts of unsaturated polyester; 0.5 to 1 part of coupling agent.

5. The modified asphalt according to claim 4, characterized in that, The polyamide fiber is an aliphatic polyamide fiber. Preferably, the polyamide fiber has a length of 3-6 mm and an aspect ratio of 100-150. And / or, the average particle size of the nano-montmorillonite is 100-200 nm; the nano-montmorillonite is one or more of sodium-based montmorillonite, calcium-based montmorillonite, and magnesium-based montmorillonite; And / or, the unsaturated polyester is one or more of 198# unsaturated polyester resin, 199# unsaturated polyester resin and 191# unsaturated polyester resin; And / or, the coupling agent is one or more of vinyltriethoxysilane, γ-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidyl etheroxypropyltrimethylsilane, and γ-methacryloyloxypropyltrimethoxysilane.

6. The modified asphalt according to any one of claims 4-5, characterized in that, The method for preparing the modified polyamide fiber includes: (a) Mix nano-montmorillonite, coupling agent, and water, then add polyamide fiber, react, filter, and dry to obtain composite polyamide fiber; (b) The composite polyamide fiber obtained in step (a) is mixed with unsaturated polyester, stirred, and dried to obtain modified polyamide fiber.

7. The modified asphalt according to claim 6, characterized in that, In step (a), the mass ratio of the nano-montmorillonite to water is 1:20 to 1:

30.

8. The modified asphalt according to claim 6, characterized in that, In step (a), the reaction conditions include: a reaction pressure of 0.2–0.5 MPa, a reaction time of 60–80 min, a reaction temperature of 40–60 °C, and the reaction is carried out under a nitrogen atmosphere. And / or, in step (a), the drying conditions are: a temperature of 100–120°C and a time of 2.5–3 hours.

9. The modified asphalt according to claim 6, characterized in that, In step (b), the stirring time is 1 to 1.5 hours, and the stirring rate is 100 to 250 r / min. And / or, in step (b), the drying conditions are: a temperature of 70–90°C and a time of 2.5–3 hours.

10. A method for preparing modified asphalt according to any one of claims 1-9, characterized in that, include: (1) Mix the solubilizer and the base asphalt, stir, and obtain blended asphalt; (2) Mix the polymer modifier, high viscosity modifier and the blended asphalt obtained in step (1), heat to swell, and shear to obtain precast asphalt; (3) Mix the precast asphalt obtained in step (2) with modified polyamide fiber, and cut it to obtain the asphalt to be developed; (4) Mix the initiator, stabilizer and the asphalt to be developed in step (3), and shear to obtain modified asphalt.

11. The method according to claim 10, characterized in that, In step (1), the base asphalt is first heated to 140-150°C, and then a solubilizer is added and stirred. And / or, the stirring rate is 200-400 r / min, and the stirring time is 0.5-1.5 hours.

12. The method according to claim 10, characterized in that, In step (2), the heating and swelling temperature is 170-180°C, preferably 170-180°C, and the time is 0.5-1h; And / or, in step (2), the shearing rate is 4000-5500 r / min and the shearing time is 0.5-1.5 hours.

13. The method according to claim 10, characterized in that, In step (3), the precast asphalt is first heated to 170-180°C, and then modified polyamide fibers are added and mixed. And / or, in step (3), the shearing conditions are: the shearing rate is 1500-2000 r / min and the shearing time is 0.5-1.5 hours.

14. The method according to claim 10, characterized in that, In step (4), the asphalt to be developed is first heated to 185-195℃, an initiator and some stabilizer are added, and it is sheared at 1500-2000 r / min for 1.0-1.5 h. Then the remaining stabilizer is added, and finally it is developed at 185-195℃ for 30-40 min to obtain modified asphalt.

15. The method according to claim 14, characterized in that, Based on the mass of the total stabilizer, the said partial stabilizer accounts for 30% to 50% of the total stabilizer, and the said remaining portion of the stabilizer accounts for 50% to 70% of the total stabilizer.

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