High-modulus asphalt binder and mixture, and preparation method for high-modulus asphalt binder

Abstract

The present application relates to a high-modulus asphalt binder and mixture, and a preparation method for the high-modulus asphalt binder. The high-modulus asphalt binder for cold regions of the present application comprises 100 parts by weight of asphalt consisting of natural asphalt and petroleum asphalt in a weight ratio of 20-50: 80-50, and 1-10 parts by weight of a modifier, wherein the ash content of the natural asphalt is as high as 60 wt% based on the weight of the natural asphalt, and trichloroethylene insoluble particles having a particle size of 10 microns or more in the asphalt binder are in a volume ratio of 5% or less. Figure 1

Description

A high modulus asphalt binder and mixture for cold regions and preparation method thereof Technical Field

[0001] The present application relates to the field of road paving materials, and in particular to a high modulus asphalt binder and mixture for use in cold regions and a preparation method thereof. Background Art

[0002] High-modulus asphalt mixture, a high-quality asphalt mixture originating from France, must simultaneously meet two criteria: a modulus (15°C, 10Hz) of no less than 14,000 MPa and a fatigue life (10°C, 25Hz, 130με) greater than 1 million cycles. Due to its excellent resistance to high-temperature deformation, durability, and strong load-bearing capacity, it is widely used internationally. With economic development, the demand for high-quality engineering construction in my country is growing. High-modulus asphalt mixture, a high-performance, low-lifecycle cost building material, has attracted the attention of many domestic construction companies and will be included in the latest edition of the industry standard, "Technical Specification for Highway Asphalt Pavement Construction," JTG F40, as a construction material for high-grade pavements.

[0003] However, the lack of low-temperature crack resistance of high-modulus asphalt mixtures is a major limitation to their widespread application in my country. The Chinese standards "Technical Guidelines for Construction of High-Modulus Asphalt Pavements for Highways" (T / CHTS 10004-2018) and GB / T36143-2018 "High-Modulus Fatigue-Resistant Asphalt Mixtures for Roads" require a low-temperature flexural failure strain of no less than 2000 με at -10°C for high-modulus asphalt mixtures. This makes them unsuitable for use in my country's cold winter regions, making them difficult to use in the vast western, northwestern, and northern regions of the country.

[0004] Chinese patent CN104194366 discloses a low-temperature resistant high-modulus composite asphalt modifier and its preparation method. The modifier, as an admixture, needs to be added to the asphalt before use. Although the low-temperature crack resistance index of the mixture is good, the examples do not mention any specific numerical values ​​of the modulus of the mixture, only dynamic stability is involved. Therefore, its high modulus properties remain to be verified. In addition, due to the complex composition of the modifier (low-temperature resistant high-modulus main agent, reinforcing binder, release agent), the preparation process has many steps and the material cost is high.

[0005] Currently, most high-modulus asphalt mixtures in China require the use of high-modulus additives, such as PRS and PRM from France, Lubao from China, and Duroflex from Germany. However, the resulting high-modulus asphalt mixtures lack low-temperature crack resistance.

[0006] Therefore, in cold areas, such as the vast western region of my country, road construction still requires asphalt mixtures that are resistant to low temperatures and have high modulus.

[0007] Summary of the Invention

[0008] The purpose of this application is to propose a high modulus asphalt binder and mixture suitable for cold regions, which has both high modulus and low temperature performance, and a preparation method thereof.

[0009] Therefore, the first aspect of the present application provides a high modulus asphalt binder for cold regions, wherein the asphalt binder comprises:

[0010] 100 parts by weight of asphalt, wherein the asphalt is composed of natural asphalt and petroleum asphalt in a weight ratio of 20-50:80-50; and

[0011] 1 to 10 parts by weight of a modifier,

[0012] The ash content in the natural asphalt is as high as 60 wt% based on the weight of the natural asphalt, and the volume proportion of trichloroethylene insoluble particles with a particle size of more than 10 microns in the asphalt binder is less than 5%.

[0013] According to one embodiment, the ash content in the natural asphalt is as high as 50 wt% based on the weight of the natural asphalt, and the volume proportion of trichloroethylene insoluble particles with a particle size of more than 10 microns in the asphalt binder is less than 3%.

[0014] According to one embodiment, the amount of the modifier is 3 to 8 parts by weight.

[0015] The natural asphalt is selected from one or more of Iranian rock asphalt, Budun rock asphalt, Trinidad Lake asphalt, and China Qingchuan rock asphalt, and the petroleum asphalt is selected from one or more of petroleum asphalts numbered 50#, 70#, 90#, and 110#.

[0016] And wherein, the modifier is selected from one or more of rubber powder, SBS and SBR; preferably, the modifier contains 1 to 5 parts by weight, preferably 3 to 5 parts by weight of SBS and / or SBR; or preferably, the modifier contains 3 to 8 parts by weight, preferably 5 to 8 parts by weight of rubber powder.

[0017] According to one embodiment, the asphalt binder further comprises 0.5 to 4 parts by weight of rubber oil, preferably 0.5 to 1.5 parts by weight of rubber oil.

[0018] The rubber oil used in the present application is not particularly limited, but aromatic rubber oil is preferably used.

[0019] According to one embodiment, the average particle size of trichloroethylene insoluble matter in the asphalt binder is 3 to 5 μm, preferably 3.5 to 4.5 μm.

[0020] Preferably, the high modulus asphalt binder for use in cold regions of the present application is composed of 100 parts by weight of asphalt and 1 to 10 parts by weight of a modifier, wherein the asphalt is composed of natural asphalt and petroleum asphalt in a weight ratio of 20 to 50:80 to 50, and wherein the ash content in the natural asphalt is as high as 60 wt%, preferably as high as 50 wt%, based on the weight of the natural asphalt, and the volume proportion of trichloroethylene insoluble particles with a particle size of more than 10 microns in the asphalt binder is less than 5%, preferably less than 3%.

[0021] The second aspect of the present application provides a high modulus asphalt mixture for cold regions, wherein the asphalt mixture contains 5 to 10 wt%, preferably 5 to 6.5 wt% of the asphalt binder according to the first aspect of the present application.

[0022] The third aspect of the present application provides a method for processing the high modulus asphalt binder for cold regions described in the first aspect of the present application, wherein the method comprises the following steps:

[0023] Crushing natural asphalt into 300-1000 mesh and mixing with all or 25-50% of molten petroleum asphalt to form an asphalt mixture;

[0024] grinding the asphalt mixture at an elevated temperature of 160° C. to 180° C.;

[0025] Adding a modifier or modified asphalt to the ground asphalt mixture to obtain the high modulus asphalt binder for cold regions,

[0026] The modified asphalt is obtained by mixing the remaining 50-75% of the petroleum asphalt as a matrix with the modifier.

[0027] According to one embodiment, the grinding is performed using a ball mill.

[0028] According to one embodiment, the temperature of the molten petroleum asphalt is 130°C to 140°C.

[0029] According to one embodiment, the asphalt mixture is mixed with the modifier or the modified asphalt at a further elevated temperature of 170°C to 180°C.

[0030] According to one embodiment, the asphalt mixture is ground at an elevated temperature of 170°C to 180°C.

[0031] This application effectively reduces the volume ratio of mineral particles with a particle size of more than 10 μm in natural asphalt by grinding natural asphalt at an elevated temperature, thereby being able to better utilize the properties of natural asphalt and combining it with a polymer modifier to obtain an asphalt binder with both high modulus and low-temperature performance.

[0032] In addition, according to the method of the present application, the mineral particles in natural asphalt can be stably suspended without the need for additional stabilizers to form a network-like stable structure in the asphalt system, avoiding the undesirable performance brought about by the addition of stabilizers, further expanding the application of natural asphalt, and expanding the available natural asphalt varieties. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG1 shows the particle size distribution of trichloroethylene insoluble matter in the binder prepared in Example 1;

[0034] FIG2 shows the particle size distribution of trichloroethylene insoluble matter in the binder prepared in Example 2;

[0035] FIG3 shows the particle size distribution of trichloroethylene insoluble matter in the binder prepared in Example 3;

[0036] FIG4 shows the particle size distribution of trichloroethylene insoluble matter in the binder prepared in Example 4;

[0037] FIG5 shows the particle size distribution of trichloroethylene insoluble matter in the binder prepared in Example 5; and

[0038] FIG6 shows the particle size distribution of trichloroethylene insoluble matter in the binder prepared in Comparative Example 1. DETAILED DESCRIPTION

[0039] As used herein, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a method or composition comprising a list of elements includes not only the elements explicitly recited, but also other elements not explicitly listed, or elements inherent to the practice of the method or composition. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional related elements in the method or apparatus comprising the element.

[0040] As used herein, the term "consisting of" is intended to indicate that a method or composition comprises only the recited elements, ie, no other elements other than the recited elements.

[0041] The elements are, for example, steps of a method, or components of a composition, etc.

[0042] The “% (percentage content)” in the asphalt binder and mixture referred to in this context refers to weight percentage unless otherwise specified.

[0043] In the preparation of the asphalt binder of the present application, grinding is carried out at a further elevated temperature (160°C to 180°C, preferably 170°C to 180°C), thereby obtaining a non-normal distribution of trichloroethylene insoluble matter in the particle size distribution. That is, in the ground asphalt, the average particle size of the mineral particles is still roughly in the range of 3 to 5 μm, but the particle size distribution conforms to a negatively skewed distribution, wherein the volume proportion of particles with a particle size of more than 10 microns is less than 5%, especially less than 3%, and even less than 1.5%. Thus, without using a particle dispersant stabilizer, the same storage stability is obtained, and the influence of these particle dispersants on the performance of the asphalt product is avoided, and the low-temperature modification effect of the polymer modifier is brought into play.

[0044] Therefore, the preparation method of the asphalt binder of the present application is to crush natural asphalt into 300-1000 mesh, mix it with molten petroleum asphalt to form an asphalt mixture; grind the asphalt mixture at an elevated temperature of 160-180°C; and finally add a modifier or modified asphalt to the ground asphalt mixture.

[0045] Before grinding, the crushed natural asphalt and the molten petroleum asphalt are mixed evenly, and then the temperature of the mixture is raised to 160-180°C, especially 170-180°C, and then grinding is carried out.

[0046] Grinding can be done using a ball mill. Grinding time varies depending on the type of natural asphalt and petroleum asphalt used, the mixing ratio, and the grinding temperature.

[0047] Particle size analysis can be used to verify that the desired average particle size and volume fraction of particles above 10 microns have been achieved.

[0048] Natural asphalt can be first mixed with a portion of petroleum asphalt and ground to obtain a natural asphalt mother liquor, which is then mixed with the petroleum asphalt modified with the modifier. The portion of petroleum asphalt used to prepare the natural asphalt mother liquor can account for 25-50% of the total weight of the petroleum asphalt in the final binder, preferably 25-40%.

[0049] In the method using natural asphalt mother liquor, the modifier can be mixed with the remaining petroleum asphalt in advance to prepare modified asphalt for standby use, thereby saving the preparation time of the binder.

[0050] The modified asphalt can be prepared by any suitable conventional method. For example, the polymer modified asphalt can be prepared by the steps of swelling, shearing, dispersion and development.

[0051] In another embodiment, natural asphalt can be mixed with all petroleum asphalt and then ground, and then a polymer modifier is added for shearing, dispersion, and development. This method can more easily obtain the desired average particle size and further simplify the preparation of the binder.

[0052] The natural asphalt used in this application is not particularly limited. When using the method of this application, both lake asphalt and rock asphalt can be used. For example, the natural asphalt that can be used in this application can be Iranian rock asphalt, Budun rock asphalt, Trinidad Lake asphalt, Qingchuan rock asphalt in China, or any combination thereof, but is not limited thereto.

[0053] According to the method of the present application, natural asphalt with an ash content of up to 60 wt%, preferably 50 wt%, can be used. Therefore, natural asphalt from most production areas can be used in the present application.

[0054] The ash content of natural asphalt indirectly indicates the effective asphalt content within the asphalt. High ash content increases processing difficulty and the risk of precipitation and segregation, but also reduces production costs. For example, Iranian rock asphalt typically has an ash content of 10%-30%, while Budun rock asphalt typically has an ash content of around 45-50% and is relatively inexpensive. Trinidad Lake asphalt typically has an ash content of around 30%, but its price is 5-7 times that of Budun rock asphalt. Therefore, the method of this application can also reduce costs to a certain extent.

[0055] Generally speaking, the finer the grinding of the mineral particles (TCE-insoluble matter) in natural asphalt, the better. For example, in this application, the average particle size of the ground TCE-insoluble matter is 3-5 μm, preferably 3.5-4.5 μm. When the average particle size of the TCE-insoluble matter is within this range, the mineral particles are more likely to be stably present in the molten asphalt.

[0056] The applicant's research has found that while the average particle size of trichloroethylene-insoluble matter can be reduced by extending the grinding time, this has a negative impact on the overall performance of the asphalt binder, especially its ductility. Prolonging the grinding time reduces the particle size of trichloroethylene-insoluble matter, while also reducing the asphalt's softening point, ductility, and other properties. Further research has revealed that when natural asphalt is mixed with molten petroleum asphalt and then ground at an elevated temperature, a negatively skewed trichloroethylene-insoluble particle size distribution is achieved. Unlike conventionally obtained normal particle size distributions, this method yields a very small proportion of larger particles. Specifically, the proportion of particles with a size of 10 microns or greater can be below 5%, even below 3%, and more particularly below 1.5%, resulting in an asphalt mixture with significantly improved natural asphalt stability. This results in an asphalt mixture that can be stored stably for extended periods without segregation, without the need for additional particle stabilization additives. Therefore, the relative content of natural asphalt in the present application can also be within a weight ratio of 20-50 natural asphalt to 80-50 petroleum asphalt. Depending on specific needs, a higher amount of natural asphalt can be selected.

[0057] In order to facilitate mixing with petroleum asphalt, natural asphalt can be crushed to 300 to 1000 mesh in advance.

[0058] Natural asphalt has excellent high-temperature performance, aging resistance, weather resistance, and water damage resistance. By adding natural asphalt within the above range, the asphalt binder and mixture obtained in this application achieve satisfactory road performance, with complex modulus and fatigue life far exceeding the specified technical indicators.

[0059] There is no particular limitation on the petroleum asphalt that can be used in this application. A suitable grade can be selected according to the needs. For example, one or more of 50#, 70#, 90#, and 110# petroleum asphalt can be selected.

[0060] As mentioned above, the modifier can be directly added to the ground asphalt mixture; or it can be pre-blended with petroleum asphalt as the base asphalt to obtain modified asphalt, and then the modified asphalt is added to the ground asphalt mixture.

[0061] Modifiers useful in this application include polymer modifiers, such as thermoplastic elastomers and rubber powder. For example, these can be rubber powder, SBS, SBR, or a combination thereof. The amount of polymer modifier added can be determined based on needs and the specific type of modifier used, typically ranging from 1 to 10 parts by weight per 100 parts by weight of asphalt.

[0062] When SBS and / or SBR are used as modifiers, the amount used can be 1 to 5 parts by weight, preferably 3 to 5 parts by weight, based on 100 parts by weight of asphalt. Rubber powder alone can also be used as the modifier for this application. The amount of rubber powder used can be 3 to 8 parts by weight, preferably 5 to 8 parts by weight, based on 100 parts by weight of asphalt.

[0063] According to another embodiment, the above modifier can be added to petroleum asphalt to prepare modified asphalt. For example, the petroleum asphalt as a matrix in the modified asphalt can account for 50-75% of the total amount of petroleum asphalt in the final asphalt binder.

[0064] In order to further improve the modification effect of the modifier or modified asphalt, rubber oil is added before adding the modifier or modified asphalt.

[0065] According to one embodiment, after grinding the asphalt mixture and before adding the modifier or modified asphalt, 0.5 to 4 parts by weight, preferably 0.5 to 1.5 parts by weight of rubber oil are added.

[0066] The rubber oil of the present application is not particularly limited, and for example, can be selected from aromatic rubber oil. The addition of rubber oil improves the compatibility of polymer modifiers such as SBS and asphalt. The molecular weight of SBS is generally hundreds of thousands, while the molecular weight of asphalt is only thousands, resulting in poor mutual compatibility and easy segregation. After adding rubber oil, the main component of rubber oil, aromatic phenol, easily enters SBS, helping it to be compatible with asphalt, thereby improving the effect of the polymer modifier.

[0067] In addition, without being limited by existing theories, it is speculated that the present application further reduces the volume proportion of large-sized (such as larger than 10 microns) mineral particles, which also helps to reduce the adverse effects of stress concentration caused by large-sized mineral particles in asphalt on low-temperature performance and has a positive effect on the stability of the system.

[0068] Through the above-mentioned improvements, this application fully utilizes the polymer modifier to improve the low-temperature performance of asphalt mixtures, and reduces the adverse effects of natural asphalt on low-temperature performance, so that the low-temperature bending failure strain is higher than the prescribed standard, thereby obtaining an asphalt product with both high modulus and low-temperature performance, providing asphalt binders and mixtures that meet technical requirements and have excellent weather resistance and service life for road construction in high-altitude and cold areas.

[0069] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0070] Test method:

[0071] Particle size and particle size distribution were measured using a Winner 2000E laser particle size analyzer produced by Jinan Micro-Nano Particle Instrument Co., Ltd.

[0072] The remaining indicators such as needle penetration and softening point are implemented in accordance with the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011).

[0073] The dynamic stability and low-temperature bending failure strain tests were carried out in accordance with the Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering (JTG E20-2011).

[0074] The complex modulus (15℃, 10Hz) and fatigue life (10℃, 25Hz, 130με) are implemented in accordance with EN12697-26 and EN12697-24 of the European asphalt mixture test method "EN12697 series of specifications".

[0075] Example 1: Preparation of asphalt binder 1

[0076] 20 kg of Budun rock asphalt (approximately 50% ash) and 3 kg of Iranian rock asphalt (approximately 9% ash) were crushed to approximately 300 mesh and added to 22 kg of SK-90 asphalt heated to 140°C. The mixture was then heated to 170°C and ground in a ball mill. 58 kg of modified asphalt (comprising 54.5 kg of SK-90 asphalt, 3 kg of SBS (DYNASOL C411 from the United States), and 0.5 kg of rubber oil) was then mixed at 180°C.

[0077] In the obtained asphalt binder, the volume proportion of trichloroethylene insoluble particles with a particle size of more than 10 microns is about 4%, the average particle size is 4.2 μm (see the particle size distribution diagram shown in Figure 1), and the needle penetration range is 25-40 dmm.

[0078] Example 2: Preparation of asphalt binder 2

[0079] 20 kg of Budun rock asphalt (approximately 50% ash) and 3 kg of Iranian rock asphalt (approximately 9% ash) were crushed to approximately 300 mesh and added to 77 kg of SK-90 asphalt heated to 140°C. The mixture was then heated to 165°C and ground in a ball mill. 0.5 kg of rubber oil was added and then mixed with 3 kg of SBS (DYNASOL C411, USA) at 180°C. After sufficient shearing in a colloid mill, the mixture was developed at 180°C for 2 hours.

[0080] In the obtained asphalt binder, the volume proportion of trichloroethylene insoluble particles with a particle size of more than 10 microns is about 3%, the average particle size is 4.0 μm (see the particle size distribution diagram shown in Figure 2), and the needle penetration range is 25-40 dmm.

[0081] Example 3: Preparation of asphalt binder 3

[0082] 35 kg of Budun rock asphalt (approximately 50% ash) was crushed to approximately 300 mesh and added to 65 kg of SK-90 asphalt heated to 140°C. The mixture was then heated to 175°C and ground at this temperature. 0.75 kg of rubber oil was added, followed by mixing with 4 kg of SBS (DYNASOL C411, USA) at 180°C. After sufficient shearing in a colloid mill, the mixture was developed at 180°C for 2 hours.

[0083] In the obtained asphalt binder, the volume proportion of trichloroethylene insoluble particles with a particle size of more than 10 microns is about 1.5%, the average particle size is 3.7 μm (see the particle size distribution diagram shown in Figure 3), and the needle penetration range is 25-40 dmm.

[0084] Example 4: Preparation of asphalt binder 4

[0085] 25 kg of Trinidad Lake asphalt (approximately 35% ash) was crushed to approximately 300 mesh and added to 75 kg of SK-90 asphalt heated to 140°C. The mixture was then heated to 165°C and ground at this temperature. 0.5 kg of rubber oil was added and then mixed with 4 kg of SBR (SBR product of Shandong Gaoshi Science and Technology Industry and Trade Co., Ltd.) at 180°C. After sufficient shearing, the mixture was passed through a colloid mill and then developed at 180°C for 2 hours.

[0086] In the obtained asphalt binder, the volume proportion of trichloroethylene insoluble particles with a particle size of more than 10 microns is about 4.5%, the average particle size is 4.4 μm (see the particle size distribution diagram shown in Figure 4), and the needle penetration range is 25-40 dmm.

[0087] Example 5: Preparation of asphalt binder 5

[0088] 40 kg of Budun rock asphalt (approximately 50% ash) was crushed to approximately 300 mesh and added to 60 kg of SK-90 asphalt heated to 140°C. The mixture was then heated to 175°C and ground at this temperature. 1.5 kg of rubber oil was added and then mixed with 8 kg of 40-mesh rubber powder at 190°C. The mixture was then passed through a colloid mill for thorough shearing.

[0089] In the obtained asphalt binder, the volume proportion of trichloroethylene insoluble particles with a particle size of more than 10 microns is about 0.5%, the average particle size is 3.4 μm (see the particle size distribution diagram shown in Figure 5), and the needle penetration range is 25-40 dmm.

[0090] Comparative Example 1

[0091] 35 kg of Budun rock asphalt (ash content about 50%) was crushed to about 300 mesh, mixed with 65 kg of SK-90 heated to 140°C, and then ground. 0.5 kg of silane coupling agent and 4 kg of SBS (C411 from DYNASOL, USA) were added. After shearing, 0.12 kg of sulfur was added. After developing for 3 hours, 0.1 kg of sasobit (SasolWax, Germany) was added and stirred for half an hour.

[0092] In the obtained asphalt binder, the volume proportion of trichloroethylene insoluble particles with a particle size of more than 10 μm is about 13%, and the average particle size is 4.8 μm (see the particle size distribution diagram shown in Figure 6).

[0093] Comparative Example 2:

[0094] 100 kg of SBS modified asphalt (the modified asphalt uses SK-90 as the base asphalt, and the SBS content accounts for 3.85% of the modified asphalt mass) was heated to 180°C to a flowable state, and 10 kg of French PR additive (French PR Company, PR additive) was added. After swelling and development for 15 minutes, high-speed shearing was performed until all the admixture particles disappeared.

[0095] Comparative Example 3:

[0096] Twenty-five kilograms of Trinidad Lake asphalt (about 35% ash) with a mesh size of about 300 was added to 79.75 kilograms of SBS modified asphalt heated to 180°C and stirred. The modified asphalt was based on SK-90 as the base asphalt, with 75 kilograms of SK-90, 4 kilograms of SBS (C411 from DYNASOL, USA), and 0.75 kilograms of rubber oil, to obtain an asphalt binder with a needle penetration range of 25-40 dmm.

[0097] Comparative Example 4:

[0098] 35 kg of budun rock asphalt (ash content of about 50%) was crushed to about 300 mesh, added to 69.75 kg of SBS modified asphalt heated to 180°C and stirred, wherein the modified asphalt is based on SK-90 as the base asphalt, with 65 kg of SK-90, 4 kg of SBS (C411 of American DYNASOL), and 0.75 kg of rubber oil, to obtain an asphalt binder with a needle penetration range of 25-40 dmm.

[0099] Binder performance test results:

[0100] The test results of the asphalt binder properties prepared in the above examples and comparative examples are shown in Table 1:

[0101] Table 1: Test results of asphalt binders prepared in Examples and Comparative Examples

[0102]

[0103] Examples 6-8 Preparation of asphalt mixture

[0104] Configure the gradation according to Table 2 and Table 3 below, and prepare the following asphalt mixtures respectively.

[0105] According to gradation 3, the asphalt binder of Example 1 was used to prepare the asphalt mixture of Example 6 at an asphalt-to-stone ratio of 5.8%.

[0106] According to gradation 1, the asphalt binder of Example 3 was used to prepare the asphalt mixture of Example 7 at an asphalt-to-stone ratio of 5.8%.

[0107] According to gradation 2, the asphalt binder of Example 3 was used to prepare the asphalt mixture of Example 8 at an asphalt-to-aggregate ratio of 5.8%.

[0108] Table 2 High modulus asphalt mixture gradation range

[0109]

[0110] Table 3 High modulus asphalt mixture gradation

[0111]

[0112] The aggregate quality should meet the requirements of the current specification "Technical Specifications for Highway Asphalt Pavement Construction" (JTG F40). The above mixture preparation process is as follows:

[0113] Heat the aggregate to 190℃, dry mix it in a mixing pot (temperature set to 185℃) for 40 seconds, add the asphalt heated to 185℃ into the mixing pot according to a certain oil-stone ratio, stir for 90 seconds, pour in the mineral powder, and mix for another 90 seconds until there is no white material, then you will get the mixture.

[0114] Comparative Examples 5-7 Preparation of Asphalt Mixture

[0115] According to Grading 2 in Table 3, the asphalt binder of Comparative Example 1 was used and the asphalt mixture of Comparative Example 5 was prepared at an oil-to-stone ratio of 5.8%.

[0116] According to Grading 2 in Table 3, the asphalt binder of Comparative Example 2 was used and the asphalt mixture of Comparative Example 6 was prepared at an asphalt-to-stone ratio of 5.8%.

[0117] According to Grading 2 in Table 3, the asphalt binder of Comparative Example 4 was used and the asphalt mixture of Comparative Example 7 was prepared at an asphalt-to-stone ratio of 5.8%.

[0118] Mixture performance test results:

[0119] The dynamic stability (60°C), low-temperature bending failure strain (-10°C), complex modulus (15°C, 10Hz), and fatigue life (10°C, 25Hz, 130με) of the asphalt mixtures of Examples 6 to 8 and Comparative Examples 5 to 7 were measured.

[0120] The test results are detailed in Table 4 below:

[0121] Table 4

[0122]

[0123] It can be seen from the comparative data that the application of conventional high modulus agents (Comparative Example 6) has the problem of insufficient fatigue and low-temperature bending crack resistance; and after adding natural asphalt and SBS for composite modification according to the traditional method (Comparative Example 7), the low-temperature crack resistance and modulus values ​​are difficult to meet the technical requirements of high modulus asphalt mixtures.

[0124] All indicators of the asphalt mixture prepared according to the method of this application meet the technical requirements.

[0125] The above description is only a preferred embodiment of the present application and does not limit the patent scope of the present application. All equivalent structural transformations made based on the contents of the present application description and drawings, or direct / indirect application in other related technical fields, are included in the patent protection scope of the present application.

Claims

1. A high modulus asphalt binder for cold regions, in, The asphalt binder comprises: 100 parts by weight of asphalt, wherein the asphalt is composed of natural asphalt and petroleum asphalt in a weight ratio of 20-50:80-50; and 1 to 10 parts by weight of a modifier, The ash content in the natural asphalt is as high as 60wt% based on the weight of the natural asphalt, and the volume proportion of trichloroethylene insoluble particles with a particle size of more than 10 microns in the asphalt binder is less than 5%.

2. The asphalt binder according to claim 1, in, The ash content in the natural asphalt is as high as 50wt% based on the weight of the natural asphalt, and the volume proportion of trichloroethylene insoluble particles with a particle size of more than 10 microns in the asphalt binder is less than 3%.

3. The asphalt binder according to claim 1, in, The asphalt is composed of natural asphalt and petroleum asphalt in a weight ratio of 20-40:80-60.

4. The asphalt binder according to claim 1, in, The amount of the modifier is 3 to 8 parts by weight.

5. The asphalt binder according to any one of claims 1 to 4, in, The natural asphalt is selected from one or more of Iranian rock asphalt, Budun rock asphalt, Trinidad Lake asphalt, and China Qingchuan rock asphalt, and the petroleum asphalt is selected from one or more of petroleum asphalts labeled 50#, 70#, 90#, and 110#.

6. The asphalt binder according to claim 1 or 2, in, The modifier is selected from one or more of rubber powder, SBS and SBR; preferably, the modifier contains 1 to 5 parts by weight, preferably 3 to 5 parts by weight of SBS and / or SBR; or preferably, the modifier contains 3 to 8 parts by weight, preferably 5 to 8 parts by weight of rubber powder.

7. The asphalt binder according to claim 1 or 2, in, The asphalt binder also includes 0.5 to 4 parts by weight of rubber oil, preferably 0.5 to 1.5 parts by weight of rubber oil.

8. The asphalt binder according to claim 1 or 2, wherein the average particle size of trichloroethylene insoluble matter in the asphalt binder is 3 to 5 μm, preferably 3.5 to 4.5 μm.

9. A high modulus asphalt mixture for cold regions. in, The asphalt mixture comprises 5 to 10 wt % of the asphalt binder according to any one of claims 1 to 8.

10. The asphalt mixture according to claim 9, in, The asphalt mixture comprises 5 to 6.5 wt % of the asphalt binder according to any one of claims 1 to 8.

11. A method for processing the high modulus asphalt binder for cold regions according to claims 1 to 8, in, The method comprises the following steps: The natural asphalt is crushed to 300-1000 meshes and mixed with all or 25-50% of molten petroleum asphalt to form an asphalt mixture; grinding the asphalt mixture at an elevated temperature of 160°C to 180°C; Adding a modifier or modified asphalt to the ground asphalt mixture to obtain the high modulus asphalt binder for cold regions, The modified asphalt is obtained by mixing the remaining 50-75% of the petroleum asphalt as a matrix with the modifier.

12. The method according to claim 11, in, The method further includes adding rubber oil after grinding the asphalt mixture.

13. The method according to claim 11, in, The grinding is performed by ball milling.

14. The method according to claim 11, in, The temperature of the molten petroleum asphalt is 130°C to 140°C.

15. The method according to any one of claims 11 to 14, in, The asphalt mixture is mixed with the modifier or the modified asphalt at a further elevated temperature of 170°C to 180°C.

16. The method according to any one of claims 11 to 14, in, The asphalt mixture was ground at an elevated temperature of 170°C to 180°C.