A method for determining artificial aging time of asphalt

Abstract

The present invention provides a method for determining the artificial aging time of asphalt, which relates to the field of road material detection technology and includes the following steps: obtaining original matrix asphalt with the same technical requirements as the matrix asphalt used for asphalt roads in a target area; obtaining asphalt of a first preset thickness on the surface of the asphalt road in the target area as sampling matrix asphalt; under a preset oxygen concentration environment, using an ultraviolet light source with a preset irradiation intensity to irradiate the original matrix asphalt in an alternating cycle of light cycles and dark cycles to obtain artificially aged matrix asphalt, wherein the total amount of ultraviolet radiation received by the original matrix asphalt in each light cycle is equal to the daily average total amount of ultraviolet radiation received by the sampled matrix asphalt; the method for determining the artificial aging time of asphalt provided by the embodiment of the present invention is closer to the aging process of asphalt roads in a natural environment, and the determined artificial light aging time is more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of road material detection, and in particular to a method for determining artificial aging time of asphalt. Background Art

[0002] With socioeconomic development and accelerating urbanization, road traffic pressure is increasing, and road quality requirements are gradually rising. In the current field of road construction, asphalt concrete remains a key material. The key to improving the practical quality of roads lies in increasing their service life, that is, their aging resistance. Asphalt concrete's aging resistance is a key source of road aging resistance. Therefore, studying the aging resistance of asphalt concrete has a positive impact on extending road service life, accelerating urban construction, and promoting economic development.

[0003] At present, there are certain differences between artificial light aging of asphalt and aging of asphalt in natural environment. The difference in light exposure is the most obvious. Artificial light aging of asphalt is usually carried out by continuous light exposure, while natural light exposure is as follows. Figure 1 As shown in the figure, the UV aging of asphalt in the natural environment is a day and night alternating aging, that is, light and dark cycle aging.

[0004] In current research on material photoaging, some researchers have found that the properties of certain materials obtained after cyclic light-dark aging differ significantly from those obtained after continuous aging. Other researchers, studying the photoaging of spiropyran hydrogels, have found that these materials undergo reversible reactions in the dark during cyclic light-dark aging. Elemental analysis of asphalt subjected to cyclic light-dark aging and continuous light aging revealed significant differences in oxygen content, despite receiving the same total amount of UV radiation. (See Table 1.) Table 1 illustrates the elemental content of three types of asphalt, suggesting that similar dark reactions may also occur during actual asphalt aging.

[0005] Table 1 Contents of elements in three types of asphalt

[0006]

[0007] Meanwhile, the temperature during traditional light aging remains constant, typically between 60°C and 80°C, significantly higher than the temperature of natural light aging. After artificial light aging, numerous wrinkles and cracks are clearly visible on the asphalt surface, with the area and extent of these cracks and wrinkles far exceeding those observed after PAV aging. However, researchers performing AFM scans on PAV-aged and light-aged asphalt have found that the surface roughness of UV-aged asphalt is lower than that of PAV-aged asphalt. This suggests that current artificial light aging methods have flaws, leading to discrepancies between simulated results and actual results. Summary of the Invention

[0008] The present invention provides a method for determining artificial aging time of asphalt, which is used to solve the problem in the prior art that the simulation results of artificial light aging methods are inconsistent with the actual situation.

[0009] The present invention provides a method for determining artificial aging time of asphalt, comprising the following steps:

[0010] Obtain original base asphalt with the same technical requirements as the base asphalt used for asphalt roads in the target area;

[0011] Obtaining asphalt of a first preset thickness on the asphalt road surface of the target area as sampling matrix asphalt;

[0012] Under a preset oxygen concentration environment, the original matrix asphalt is irradiated using an ultraviolet light source of preset irradiation intensity in an alternating cycle of light and dark periods to obtain an artificially aged matrix asphalt, wherein the total amount of ultraviolet radiation received by the original matrix asphalt in each light cycle is equal to the daily average total amount of ultraviolet radiation received by the sampled matrix asphalt;

[0013] The sampled matrix asphalt, the original matrix asphalt and the artificially aged matrix asphalt are subjected to an asphalt dynamic shear rheology test to obtain the complex moduli of the sampled matrix asphalt, the original matrix asphalt and the artificially aged matrix asphalt respectively;

[0014] Determine an equivalent calculation formula for artificial ultraviolet aging time and natural ultraviolet aging time based on the corresponding relationship between the complex moduli of the sampled matrix asphalt, the original matrix asphalt, and the artificially aged matrix asphalt;

[0015] The artificial light aging time is calculated based on the equivalent calculation formula of artificial UV light aging time and natural UV light aging time and the duration of natural UV light aging.

[0016] According to an embodiment of the present invention, a method for determining artificial aging time of asphalt is provided, wherein the following steps are further performed before the step of irradiating the original base asphalt using an ultraviolet light source of preset irradiation intensity in a manner of alternating light periods and dark periods:

[0017] The original base asphalt is heated to a fluid state and poured into a heat-resistant tray to obtain the original base asphalt of a second preset thickness.

[0018] According to an embodiment of the present invention, a method for determining artificial aging time of asphalt is provided, wherein after performing the step of heating the original base asphalt to a fluid state and pouring the asphalt into a heat-resistant tray, the following steps are further performed:

[0019] The original base asphalt of the second preset thickness is cooled to a preset temperature.

[0020] According to a method for determining artificial aging time of asphalt provided by an embodiment of the present invention, when the climate zone of the target area is 2-1 or 3-2, the original base asphalt is No. 110 base asphalt, the needle penetration of the No. 110 base asphalt is 100 dmm-120 dmm, the softening point of the No. 110 base asphalt is greater than or equal to 43°C, and the ductility of the No. 110 base asphalt is greater than 100 cm at 15°C; when the climate zone of the target area is 1-1, 1-2, 1-3, 2-2 or 2-3, the original base asphalt is 90 No. 90 matrix asphalt, the needle penetration of the No. 90 matrix asphalt is 80dmm-100dmm, the softening point of the No. 90 matrix asphalt is greater than or equal to 45°C, and the ductility of the No. 90 matrix asphalt is greater than 100cm at 15°C; when the climate zone of the target area is 1-4 or 2-4, the original matrix asphalt is No. 70 matrix asphalt, the needle penetration of the No. 70 matrix asphalt is 60dmm-80dmm, the softening point of the No. 70 matrix asphalt is greater than or equal to 46°C, and the ductility of the No. 70 matrix asphalt is greater than 100cm at 15°C.

[0021] According to a method for determining artificial aging time of asphalt provided by an embodiment of the present invention, the ratio of the light cycle time to the dark cycle time is equal to the ratio of the daytime to the nighttime of the target area.

[0022] According to a method for determining the artificial aging time of asphalt provided by an embodiment of the present invention, the ambient temperature in the light cycle is Tlight = T+30°C, and the ambient temperature in the dark cycle is Tdark = T-15°C, wherein T is the annual average daily temperature of the target area.

[0023] According to a method for determining artificial aging time of asphalt provided by an embodiment of the present invention, the preset oxygen concentration is equal to the daily average oxygen concentration of the target area.

[0024] According to a method for determining artificial aging time of asphalt provided by an embodiment of the present invention, the sampled base asphalt is base asphalt that has not been compacted by a vehicle.

[0025] According to a method for determining the artificial aging time of asphalt provided by an embodiment of the present invention, the temperature of the original matrix asphalt when heated is 125°C-145°C, and the heating time is 1.5h-2h; the first preset thickness is 1.5mm-2mm, and the second preset thickness is 1.5mm-2.0mm.

[0026] According to a method for determining artificial aging time of asphalt provided by an embodiment of the present invention, the preset temperature is 18°C-22°C.

[0027] According to a method for determining artificial aging time of asphalt provided by an embodiment of the present invention, the asphalt roads in the target area are asphalt roads that have been completed and opened to traffic for 1-5 years.

[0028] The method for determining the artificial aging time of asphalt provided in an embodiment of the present invention uses an ultraviolet light source of preset irradiation intensity to irradiate the original base asphalt in an alternating cycle of light and dark cycles under a preset oxygen concentration environment, so that the total amount of ultraviolet radiation received by the original base asphalt in each light cycle is equal to the daily average total amount of ultraviolet radiation received by the sampled base asphalt; to ensure that the artificial light aging phenomenon is similar to the natural aging phenomenon. By using the original base asphalt with the same technical requirements as the base asphalt used for asphalt roads in the target area, using the second theorem of similarity theory, a corresponding relationship is established between the rutting factor of the asphalt after natural light aging and the rutting factor of the artificially aged base asphalt, and the similarity modulus is calculated, thereby obtaining an equivalent relationship between the time of artificial light aging and the time of natural light aging, thereby determining the artificial light aging time. The method for determining the artificial aging time of asphalt provided in an embodiment of the present invention is closer to the aging process of asphalt roads in natural environments, and the determined artificial light aging time is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 Schematic diagram of the principle of the natural lighting method provided by an embodiment of the present invention;

[0031] Figure 2 1 is a flow chart of a method for determining artificial aging time of asphalt provided in an embodiment of the present invention;

[0032] Figure 3 Schematic diagram of the principle of the ultraviolet irradiation method provided by an embodiment of the present invention;

[0033] Figure 4 It is a schematic diagram of the principle of the temperature control method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0035] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0036] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on the specific circumstances.

[0037] In the embodiments of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," or "above" a second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," or "below" a second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0038] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0039] The following combination Figure 2-Figure 4 The method for determining the artificial aging time of asphalt according to an embodiment of the present invention is described.

[0040] like Figure 2 As shown, the method for determining the artificial aging time of asphalt includes the following steps:

[0041] Step 110, obtaining original base asphalt that has the same technical requirements as the base asphalt used for asphalt roads in the target area;

[0042] It should be noted here that the original base asphalt refers to the base asphalt that has not been irradiated with ultraviolet light. The original base asphalt and the base asphalt used for asphalt roads in the target area have the same technical requirements, which means that the softening point, ductility and needle penetration of the two are the same.

[0043] Step 120 , obtaining asphalt of a first preset thickness on the asphalt road surface in the target area as sampling matrix asphalt;

[0044] It should be noted here that the asphalt road in the target area is an asphalt road that has been completed and opened to traffic for 1-5 years. The first preset thickness is 1.5mm-2mm. Preferably, 2cm thick asphalt on the surface of the asphalt road in the target area is used as the sampling matrix asphalt, and the sampling matrix asphalt is matrix asphalt that has not been compacted by vehicles.

[0045] Step 130: irradiating the original matrix asphalt with an ultraviolet light source of preset irradiation intensity in an alternating cycle of light and dark periods under a preset oxygen concentration environment to obtain an artificially aged matrix asphalt, wherein the total amount of ultraviolet radiation received by the original matrix asphalt in each light cycle is equal to the daily average total amount of ultraviolet radiation received by the sampled matrix asphalt;

[0046] Since the sampled matrix asphalt is aged by ultraviolet light in a natural environment, in order to ensure the accuracy of the experiment, the original matrix asphalt needs to be aged in a preset oxygen concentration environment. The preset oxygen concentration is equal to the daily average oxygen concentration in the target area.

[0047] It should be noted that a light cycle refers to a period of time during which the as-preserved base asphalt is irradiated with a UV light source, while a dark cycle refers to a period of time during which the as-preserved base asphalt is not irradiated, even if the as-preserved base asphalt is in a dark environment. Both light and dark cycles are conducted in an aerobic environment.

[0048] The total daily average UV radiation can be obtained by checking the meteorological data of the district and county where the target area is located. According to the relevant meteorological data, the total daily average UV radiation in the country is 4190mj / m 2 a~8400mj / m 2 ·a.

[0049] Step 140, performing an asphalt dynamic shear rheology test on the sampled base asphalt, the original base asphalt, and the artificially aged base asphalt to obtain the complex moduli of the sampled base asphalt, the original base asphalt, and the artificially aged base asphalt, respectively;

[0050] The complex modulus of the above three types of asphalt can be determined separately through the asphalt dynamic shear rheology experiment. The complex modulus of the artificially aged matrix asphalt is M1, and the artificial light aging time is t1; the complex modulus of the sampled matrix asphalt is M2, and the time since the construction of the road where the sampled matrix asphalt is located is t2. When the road is determined, t2 can also be determined; the complex modulus of the original matrix asphalt is M3.

[0051] Step 150, determining an equivalent calculation formula for artificial UV aging time and natural UV aging time based on the corresponding relationship between the complex moduli of the sampled matrix asphalt, the original matrix asphalt, and the artificially aged matrix asphalt;

[0052] According to the second theorem of similarity principle, during the UV aging process of asphalt, the initial physical conditions and aging parameters of asphalt are similar. It can be considered that artificial light aging and natural light aging are the same phenomenon. Therefore, the similarity modulus can be calculated by the following formula (1):

[0053]

[0054] Therefore, the calculation formula for the time equivalence between artificial light aging and natural light aging is: t1 = T × t2, where T is the time equivalence conversion coefficient between artificial light aging and natural light aging. Using the above formula, we can calculate the equivalent calculation relationship between artificial light aging time and natural light aging time.

[0055] Step 160 , calculating the artificial light aging time according to the equivalent calculation formula of the artificial ultraviolet light aging time and the natural ultraviolet light aging time and the natural ultraviolet light aging time.

[0056] The method for determining the artificial aging time of asphalt provided in an embodiment of the present invention uses an ultraviolet light source of preset irradiation intensity to irradiate the original base asphalt in an alternating cycle of light and dark cycles under a preset oxygen concentration environment, so that the total amount of ultraviolet radiation received by the original base asphalt in each light cycle is equal to the daily average total amount of ultraviolet radiation received by the sampled base asphalt; to ensure that the artificial light aging phenomenon is similar to the natural aging phenomenon. By using the original base asphalt with the same technical requirements as the base asphalt used for asphalt roads in the target area, using the second theorem of similarity theory, a corresponding relationship is established between the rutting factor of the asphalt after natural light aging and the rutting factor of the artificially aged base asphalt, and the similarity modulus is calculated, thereby obtaining an equivalent relationship between the time of artificial light aging and the time of natural light aging, thereby determining the artificial light aging time. The method for determining the artificial aging time of asphalt provided in an embodiment of the present invention is closer to the aging process of asphalt roads in natural environments, and the determined artificial light aging time is more accurate.

[0057] According to an embodiment of the present invention, before performing the step of irradiating the original base asphalt using an ultraviolet light source with a preset irradiation intensity in a manner of alternating light periods and dark periods, the following steps are further performed:

[0058] The original base asphalt is heated to a fluid state and poured into a heat-resistant tray to obtain the original base asphalt of a second preset thickness.

[0059] Because the original base asphalt is blocky and uneven in thickness, it receives uneven illumination, affecting the accuracy of the measurement results. According to the asphalt sampling method outlined in JTG E20-2011, "Test Procedure for Asphalt and Asphalt Mixtures for Highway Engineering," the original base asphalt must be placed in an oven for heating. The oven is heated by heating pipes and supplied with air by a motor to bring the internal temperature to the set point.

[0060] The original matrix asphalt is heated at a set temperature of 125°C to 145°C (135°C in this embodiment) and for a heating time of 1.5 to 2 hours. Once the original matrix asphalt is heated to a fluid state, it is poured into a heat-resistant pan. The thickness of the original matrix asphalt becomes uniform, ultimately reaching a predetermined thickness. The predetermined thickness is 1.5 mm to 2.0 mm, preferably 2 mm, meaning the liquid level of the original matrix asphalt is 2 mm above the bottom of the pan.

[0061] It should be noted here that the material performance of the heat-resistant plate must be stable, the bottom must be flat, and the area of ​​the bottom must be convenient for measurement.

[0062] According to an embodiment of the present invention, after performing the step of heating the original base asphalt to a fluid state and pouring the asphalt into a heat-resistant tray, the following steps are further performed:

[0063] The original base asphalt of the second preset thickness is cooled to a preset temperature, wherein the preset temperature is 18°C-22°C.

[0064] According to an embodiment of the present invention, the climate zone of the target area should be determined in accordance with the "applicable climate zone method" specified in the "Technical Specifications for Highway Asphalt Pavement Construction" JTG F40. When the climate zone of the target area is 2-1 or 3-2, the original base asphalt is No. 110 base asphalt, the needle penetration of No. 110 base asphalt is 100dmm-120dmm, the softening point of No. 110 base asphalt is greater than or equal to 43°C, and the ductility of No. 110 base asphalt is greater than 100cm at 15°C; when the climate zone of the target area is 1-1, 1-2, 1-3, 2-2 or 2-3, the original base asphalt is No. 90 base asphalt, and the ductility of No. 90 base asphalt is greater than 100cm at 15°C. The needle penetration of green asphalt is 80dmm-100dmm, the softening point of No. 90 matrix asphalt is greater than or equal to 45℃, and the ductility of No. 90 matrix asphalt is greater than 100cm at 15℃; when the climate zone of the target area is 1-4 or 2-4, the original matrix asphalt is No. 70 matrix asphalt, the needle penetration of No. 70 matrix asphalt is 60dmm-80dmm, the softening point of No. 70 matrix asphalt is greater than or equal to 46℃, and the ductility of No. 70 matrix asphalt is greater than 100cm at 15℃.

[0065] According to an embodiment of the present invention, the ratio of the light cycle time to the dark cycle time is equal to the ratio of the day time to the night time of the target area.

[0066] According to an embodiment of the present invention, the ambient temperature T 照 =T+30℃, ambient temperature during dark period T 暗 =T-15°C, where T is the annual average daily temperature of the target area. The annual average daily temperature of the target area is the annual average daytime temperature within the county where the target area is located. The annual average daytime temperature across China is generally 15°C to 25°C.

[0067] According to an embodiment of the present invention, the sampled base asphalt is a base asphalt that has not been compacted by vehicles. Using a base asphalt that has not been compacted by vehicles can avoid the influence of external forces on the properties of the asphalt.

[0068] According to an embodiment of the present invention, a method for determining artificial aging time of asphalt comprises the following steps:

[0069] Step 210, obtaining original base asphalt that has the same technical requirements as the base asphalt used for asphalt roads in the target area;

[0070] Step 220 , obtaining asphalt of a first preset thickness on the asphalt road surface in the target area as sampling matrix asphalt;

[0071] Step 230 , heating the original base asphalt to a fluid state and pouring the original base asphalt into a heat-resistant tray to obtain the original base asphalt of a second predetermined thickness;

[0072] Step 240 , cooling the original base asphalt of the second preset thickness to a preset temperature;

[0073] Step 250: irradiating the original matrix asphalt with an ultraviolet light source of a preset irradiation intensity in an alternating cycle of light and dark periods under a preset oxygen concentration environment to obtain an artificially aged matrix asphalt, wherein the total amount of ultraviolet radiation received by the original matrix asphalt in each light cycle is equal to the daily average total amount of ultraviolet radiation received by the sampled matrix asphalt;

[0074] Step 260: Performing an asphalt dynamic shear rheology test on the sampled base asphalt, the original base asphalt, and the artificially aged base asphalt to obtain the complex moduli of the sampled base asphalt, the original base asphalt, and the artificially aged base asphalt, respectively.

[0075] Step 270, determining an equivalent calculation formula for artificial UV aging time and natural UV aging time based on the corresponding relationship between the complex moduli of the sampled matrix asphalt, the original matrix asphalt, and the artificially aged matrix asphalt;

[0076] Step 280 , calculating the artificial light aging time according to the equivalent calculation formula of the artificial ultraviolet light aging time and the natural ultraviolet light aging time and the natural ultraviolet light aging time.

[0077] After obtaining the artificial light aging time according to the above steps, an asphalt sample may be prepared and artificial light aging may be performed again according to the above steps 210 to 240 to verify the accuracy of the calculated artificial light aging time.

[0078] The following combination Figure 3 and Figure 4 Describe a specific embodiment of the present invention, such as Figure 3 and Figure 4 As shown in the figure, the natural environment of Lhasa, Tibet Autonomous Region is used as the reference standard for natural light aging. The average annual daytime temperature in this area is 17°C (the ambient temperature during the light cycle is T 照 =47℃, ambient temperature during dark period T 暗 =2℃), the average sunshine duration (i.e. the time when sunlight directly hits the ground) is 8.5h. The annual total radiation is 580kj / cm 2 a-730kj / cm 2 a, of which ultraviolet radiation accounts for 4%-5% of the total radiation. Calculated under the most unfavorable conditions, assuming the total radiation is 730kj / cm 2 a. If the UV radiation accounts for 5%, the UV radiation amount is 36.5 kJ / cm 2 a, converted to an average daily total of 100 j / cm 2d. Assume that a UV-340 type UV lamp is used to irradiate the original matrix asphalt with a light-dark cycle. The aging area is 0.5m away from the lamp. The UV intensity at the aging area is measured by a UV irradiator to be 12×10 3 μw / cm 2 .

[0079] According to the principle of equal total amount of ultraviolet radiation, the time of artificial light aging is calculated according to the following formula (2).

[0080]

[0081] In formula (2), t is the illumination time of a light-dark cycle, p1 is the artificial ultraviolet radiation power, and w2 is the average daily natural ultraviolet radiation in Lhasa, Tibet Autonomous Region.

[0082] According to formula (2), the artificial photoaging exposure time equivalent to the total amount of photoaging radiation in the natural environment in one day is 2.3 hours. Figure 2 and Figure 3 Based on the day-night ratio of this area, it can be calculated that the light-dark cycle of artificial photoaging is 7 hours, with the light time of one light-dark cycle being 2.3 hours and the dark time being 4.7 hours. The temperature when the light is on is 47°C and the temperature when it is dark is 2°C.

[0083] Using the aforementioned artificial light aging method, the original base asphalt was artificially light aged for 700 hours (100 cycles) and then removed. Dynamic shear rheological tests were conducted alongside the original base asphalt and base asphalt samples from a two-year-old asphalt road in Lhasa. The complex moduli of the three asphalts were obtained, as shown in Table 2 below.

[0084] Table 2 Complex modulus of three asphalts

[0085]

[0086] Using formula (1), we can calculate the similarity modulus T = 0.88. Since the equivalent calculation formula for artificial UV aging time and natural UV aging time and the duration of natural UV aging are both known, the equivalent relationship for aging time is: 700h = 0.88 × 2a, that is, the performance of asphalt aged indoors for 700 hours is equivalent to the performance of asphalt aged outdoors for 1.76 years. This gives the conversion relationship between artificial light aging time and natural light aging time in Lhasa, as shown in Table 3.

[0087] Table 3 Aging conversion table

[0088]

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for determining the artificial aging time of asphalt, characterized in that: The following steps are involved: Obtain original base asphalt with the same technical requirements as the base asphalt used for asphalt roads in the target area; Obtaining asphalt of a first preset thickness on the asphalt road surface of the target area as sampling matrix asphalt; Under a preset oxygen concentration environment, the original matrix asphalt is irradiated using an ultraviolet light source of preset irradiation intensity in an alternating cycle of light and dark periods to obtain an artificially aged matrix asphalt, wherein the total amount of ultraviolet radiation received by the original matrix asphalt in each light cycle is equal to the daily average total amount of ultraviolet radiation received by the sampled matrix asphalt; The sampled matrix asphalt, the original matrix asphalt and the artificially aged matrix asphalt are subjected to an asphalt dynamic shear rheology test to obtain the complex moduli of the sampled matrix asphalt, the original matrix asphalt and the artificially aged matrix asphalt respectively; According to the corresponding relationship between the complex moduli of the sampled matrix asphalt, the original matrix asphalt and the artificially aged matrix asphalt, the equivalent calculation formula of the artificial ultraviolet aging time and the natural ultraviolet aging time is determined; that is, the calculation is performed by the following formula (1): Where T is the time equivalence conversion coefficient between artificial light aging and natural light aging, M1 is the complex modulus of the artificially aged matrix asphalt, M2 is the complex modulus of the sampled matrix asphalt, and M3 is the complex modulus of the original matrix asphalt. The calculation formula for the time equivalence relationship between artificial light aging and natural light aging is: t1 = T × t2, where t1 is the artificial light aging time and t2 is the time since the road where the sampled matrix asphalt is located was built. The artificial light aging time is calculated based on the equivalent calculation formula of artificial UV light aging time and natural UV light aging time and the duration of natural UV light aging.

2. The method for determining the artificial aging time of asphalt according to claim 1, characterized in that: Before performing the step of irradiating the original matrix asphalt using an ultraviolet light source with a preset irradiation intensity in a manner of alternating light cycles and dark cycles, the following steps are further performed: The original base asphalt is heated to a fluid state and poured into a heat-resistant tray to obtain the original base asphalt of a second preset thickness.

3. The method for determining the artificial aging time of asphalt according to claim 2, characterized in that: After performing the step of heating the original base asphalt to a fluid state and pouring the asphalt into a heat-resistant tray, the following steps are further performed: The original base asphalt of the second preset thickness is cooled to a preset temperature.

4. The method for determining the artificial aging time of asphalt according to any one of claims 1 to 3, characterized in that: The ratio of the light cycle time to the dark cycle time is equal to the ratio of the day time to the night time of the target area.

5. The method for determining the artificial aging time of asphalt according to any one of claims 1 to 3, characterized in that: The ambient temperature T during the photoperiod 照 =T+30°C, the ambient temperature during the dark period T 暗 =T-15°C, where T is the annual average daily temperature of the target area.

6. The method for determining artificial aging time of asphalt according to any one of claims 1 to 3, characterized in that: The preset oxygen concentration is equal to the daily average oxygen concentration of the target area.

7. The method for determining artificial aging time of asphalt according to any one of claims 1 to 3, characterized in that: The sampled base asphalt is base asphalt that has not been compacted by a vehicle.

8. The method for determining artificial aging time of asphalt according to claim 2 or 3, characterized in that: The temperature of the original matrix asphalt during heating is 125° C.-145° C., and the heating time is 1.5 h-2 h; the first preset thickness is 1.5 mm-2 mm, and the second preset thickness is 1.5 mm-2.0 mm.

9. The method for determining artificial aging time of asphalt according to claim 3, characterized in that: The preset temperature is 18°C-22°C.

10. The method for determining artificial aging time of asphalt according to claim 1, characterized in that: The asphalt roads in the target area are asphalt roads that have been completed and opened to traffic for 1-5 years.

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