Method for testing ultraviolet aging resistance of asphalt and application thereof

Abstract

This invention relates to the field of building technology, and provides a test method for the resistance of asphalt to ultraviolet aging and its application. The test method includes: determining the average daily night-day time ratio k in the application area. 平均 Daytime high temperature C 光 The highest temperature at night is C 黑 and daily average radiation intensity P 平均 The asphalt to be tested was placed in an aging chamber for light exposure, followed immediately by exposure to darkness; at different time points t during the period from the start to the end of the exposure to darkness. i Infrared spectroscopy was performed on asphalt samples, and the change in the benzene ring substituent index ΔI was calculated. 平均 ; Using ΔI 平均 Calculate the diffusion rate V 扩散 ; Utilizing the diffusion rate V 扩散 V represents the resistance of the asphalt to ultraviolet aging under the climatic conditions of the application area. 扩散 The larger the value, the worse the resistance of the asphalt to UV aging in the application area. The test method of the present invention uses the diffusion rate of substances inside the asphalt, characterized by the benzene ring substituent index, to measure the resistance of the asphalt to UV aging.

Description

Technical Field

[0001] This invention relates to the field of building technology, and to a test method for the UV resistance of asphalt and its application, particularly to a test method for the UV resistance of asphalt based on diffusion rate and its application. Background Technology

[0002] To assess the UV aging resistance of asphalt and provide reference suggestions for asphalt material selection in high-altitude areas with abundant ultraviolet radiation, patent application CN115096804A provides a method for evaluating the UV aging resistance of asphalt. Specifically, the aged asphalt sample is dissolved and then solidified, followed by compliance coefficient and fatigue factor tests. The aged sample needs to be fully fused and homogeneous. Although this method takes into account the objective situation of uneven aging within the asphalt during the aging process, it is a layered method at the millimeter level and uses the direct fusion of upper and lower layers for comprehensive judgment. This does not conform to the fact that the aging degree of each layer is different during the UV aging process under natural conditions, and therefore cannot achieve accurate measurement.

[0003] Therefore, this invention is proposed. Summary of the Invention

[0004] To overcome the above problems, this invention provides a test method for the UV resistance of asphalt and its application. This invention calculates the diffusion rate of asphalt through microscopic experiments and uses it to evaluate the UV resistance of asphalt. Moreover, the test method of this invention is simple and quick.

[0005] Specifically, the present invention provides a method for testing the UV resistance of asphalt, comprising the following steps: (1) Based on the climate data of the application area, determine the average daily night-day length ratio k of the area. 平均 Daytime high temperature C 光 The highest temperature at night is C 黑 and daily average radiation intensity P 平均 .

[0006] The application area refers to the following: the asphalt to be tested in this invention is generally used as a road surface material. Road surfaces in different geographical locations have different environments. The application area includes environmental parameters obtained for a specific geographical location, including ambient temperature and radiation intensity. Here, the ratio of the average daily nighttime to daytime hours in the selected area is k. 平均 Daytime high temperature C 光 The highest temperature at night is C 黑 and daily average radiation intensity P 平均These four parameters, which serve as references for the testing method of this invention, are crucial for calculating the diffusion rate of asphalt through microscopic experiments and for successfully evaluating the UV aging resistance of asphalt. These parameters can all be obtained using methods known in the art.

[0007] (2) The asphalt to be tested was placed in an aging chamber for light exposure, and then immediately protected from light; the light exposure time was t. 光照 And the time of light avoidance is t 避光 The light temperature during the illumination period is the highest daytime temperature C. 光 The light intensity is P, and the light-avoidance temperature during the light-avoidance period is the highest nighttime temperature C. 黑 Where P = N × P 平均 N is the light intensity amplification factor, 3≤N≤5.

[0008] If the light intensity P in step (2) is too high or too low, it will affect the accuracy of the present invention in evaluating the UV aging resistance of asphalt.

[0009] (3) At different time points t during the period from the start to the end of light avoidance. i Infrared spectroscopy was performed on samples of the asphalt to be tested at depths ranging from 50 μm to 150 μm below the asphalt surface. The change in the benzene ring substituent index was calculated to obtain t. i The ratio of the dark time of sample i at time k i and the corresponding change in the benzene ring substituent index ΔI i , where i is a positive integer.

[0010] Establish a rectangular coordinate system, with the dark time ratio k as the abscissa and the change in the benzene ring substituent index ΔI as the ordinate. 苯环 Using the vertical coordinate as the ordinate, construct several points M in the rectangular coordinate system. i (k) i ΔI i ), for the aforementioned points M i (k) i ΔI i Curve fitting is performed to obtain curve m.

[0011] Appropriate sampling depth plays a crucial role in the rationality of the method of this invention. If the sampling depth is too deep or too shallow, the method of this invention will be unable to evaluate the UV aging resistance of asphalt.

[0012] (4) Calculate using curve m when k takes the value k 平均 At that time, the average change in the benzene ring substituent index ΔI 平均 .

[0013] The general meaning of the above calculation using curve m is: to calculate k=k 平均Substituting the function obtained by fitting curve m, we can calculate ΔI. 平均 .

[0014] (5) From the aforementioned ΔI 平均 Calculate the diffusion rate V 扩散 .

[0015] (6) Using the diffusion rate V 扩散 V represents the resistance of the asphalt to ultraviolet aging under the climatic conditions of the application area. 扩散 The larger the value, the worse the resistance of the asphalt to ultraviolet aging in the application area.

[0016] The illumination and sampling testing methods are all performed in accordance with the methods in patent application CN116642806A.

[0017] According to the test method for the UV resistance of asphalt provided by the present invention, the t 光照 Determined by the type of asphalt: When the asphalt to be tested is base asphalt, t 光照 ≥72h; when the asphalt to be tested is blended asphalt, t 光照 ≥24h.

[0018] According to the test method for the UV resistance of asphalt provided by the present invention, the t 避光 By t 光照 Decision: t 光照 ≤t 避光 ≤2t 光照 .

[0019] Regarding the method of the present invention, t 避光 The value of t and t 光照 The value of the light-shielding time is closely related to the efficiency of the experiment. Sufficient light-shielding time helps with sampling and obtaining more sampling points, but too long a light-shielding time is not conducive to improving experimental efficiency. The method of this invention can evaluate the UV aging resistance of different asphalts from microscopic test results in a short time with higher accuracy.

[0020] The aforementioned base asphalt refers to Grade A, Grade B, and Grade C road petroleum asphalt, generally including asphalt with grades such as 70#, 90#, and 110#.

[0021] The aforementioned blended asphalt refers to asphalt produced by combining soft and hard components in a certain proportion using a predetermined blending process or technology, taking advantage of the complementary nature of the blending components. It generally includes Shell asphalt, Esso asphalt, Panjin asphalt, etc.

[0022] The test method for the UV aging resistance of asphalt provided by the present invention includes: k i =t i / t 光照 .

[0023] The method for testing the UV resistance of asphalt according to the present invention includes: point M i (k) i ΔI i The change in the benzene ring substituent index ΔI i The calculation formula is: ΔI i =|I i -I0|, where I i The time for avoiding light is t. i The benzene ring substituent index is obtained by infrared spectroscopy testing of samples taken at specific time points. I0 represents the benzene ring substituent index obtained by infrared spectroscopy testing of unexposed asphalt.

[0024] According to the test method for the UV aging resistance of asphalt provided by the present invention, the curve fitting method includes: the curve m consists of at least 3 different time points t. i The measured values ​​were obtained by curve fitting, the fitting function was an exponential function, and the fitting correlation coefficient R was... 2 ≥95%.

[0025] The method for testing the UV resistance of asphalt according to the present invention includes: the curve m passes through three points with coordinates M1(k1, ΔI1), M2(k2, ΔI2), and M3(k3, ΔI3) respectively, corresponding to light-shielding times of sampling tests t1, t2, and t3 respectively, and satisfies: 0 < t1 < t2 < t3 ≤ t 避光 .

[0026] The test method for the UV resistance of asphalt according to the present invention includes: any two adjacent points M on curve m. i With point M i+1 The x-axis interval is not less than 1 / 5t 光照 .

[0027] Appropriate intervals help reduce the number of samples and shorten testing time. Experiments have shown that within the aforementioned time interval range, experiments can be simplified while ensuring accuracy.

[0028] According to the test method for the UV resistance of asphalt provided by the present invention, the V 扩散 The calculation formula is: V 扩散 =ΔI 平均 / (t) 光照 +k 平均 ×t 光照 ).

[0029] Secondly, the present invention also provides an application of the test method for the UV aging resistance of asphalt as described above, including: using asphalt 1# as the asphalt to be tested to obtain its curve m. 1# Using curve m 1# Get V 扩散1 Using asphalt #2 as the asphalt to be tested, its curve m was obtained. 2# Using curve m 2# Get V 扩散2 If the diffusion rate V corresponding to asphalt #1 扩散1 The diffusion rate V is greater than that of asphalt #2. 扩散2 If the UV aging resistance of asphalt 1# is weaker than that of asphalt 2#, then the UV aging resistance of asphalt 1# is stronger than that of asphalt 2#.

[0030] When comparing Asphalt 1# and Asphalt 2#, which are intended to be applied to the same area, the environmental parameters during the testing process are the same.

[0031] This invention provides a test method and application for the UV resistance of asphalt. It utilizes the diffusion capacity of asphalt to characterize its UV resistance. Using a matching test method, the diffusion rate is calculated, and this index is then used to measure the UV resistance of asphalt, thereby selecting road asphalt more suitable for corresponding conditions. The test method of this invention is simple and quick. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 The time axis diagram shows the test results for Z90# and Q70# base asphalt.

[0034] Figure 2 The change in benzene ring substituent index ΔI between the shallow (100μm) and deep (500μm) layers of Z90# asphalt. 苯环 Comparison chart of corresponding curve fitting results.

[0035] Figure 3 The change in carbonyl index ΔI between the shallow (100μm) and deep (500μm) layers of Z90# asphalt. 羰基 Comparison chart of corresponding curve fitting results.

[0036] Figure 4 The curve fitting results are for the rate of change of irreversible creep compliance ΔJ of Z90# asphalt.

[0037] Figure 5 The change in the benzene ring substituent index ΔI in the shallow 100μm layer of Z90# asphalt 苯环 A comparison of the curve fitting results for the rate of change of irreversible creep compliance ΔJ.

[0038] Figure 6 The change in benzene ring substituent index ΔI between the shallow (100μm) and deep (500μm) layers of Q70# asphalt. 苯环 Comparison chart of corresponding curve fitting results.

[0039] Figure 7 The change in carbonyl index ΔI between the shallow (100μm) and deep (500μm) layers of Q70# asphalt. 羰基 Comparison chart of corresponding curve fitting results.

[0040] Figure 8 The curve fitting results are for the rate of change of irreversible creep compliance ΔJ of Q70# asphalt.

[0041] Figure 9 The change in the benzene ring substituent index ΔI in the shallow 100μm layer of Z90# asphalt 苯环 A comparison of the curve fitting results for the rate of change of irreversible creep compliance ΔJ.

[0042] Figure 10 The change in the benzene ring substituent index ΔI in the shallow 100μm layer of Z90# and Q70# asphalt. 苯环 Comparison chart of corresponding curve fitting results.

[0043] Figure 11 This is a comparison chart of the curve fitting results corresponding to the irreversible creep compliance change rate ΔJ of Z90# asphalt and Q70# asphalt.

[0044] Figure 12 The variation ΔI of the benzene ring substituent index in different blended asphalts 苯环 Comparison chart of corresponding curve fitting results. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0046] The following is combined with Figures 1-12 This invention describes a test method for the resistance of asphalt to ultraviolet aging and its application.

[0047] Example 1 Taking region A as an example, the candidate asphalts are Z90# base asphalt and Q70# base asphalt. Querying the climate data for application region A yields the following: the average daily night-day length ratio k... 平均 It is 3 / 2; the highest daytime temperature is C. 光 The highest temperature at night is 60℃; 黑 The temperature was 20℃; and the average daily radiation intensity P 平均 3200 μw / cm 2 .

[0048] The experimental lighting conditions were set as follows: light temperature 60℃, light-shielding temperature 20℃, and light intensity 11000 μw / cm². 2 .

[0049] Z90# Asphalt: Z90# asphalt was placed in an aging chamber for testing. The test timeline is shown in the figure below. Figure 1 As shown.

[0050] Asphalt exposure time t 光照 =72h, light-avoidance time t 避光 =72h, where the test time points are t1=0h, t2=24h, and t3=72h; corresponding to k1=0, k2=1 / 3, and k3=1. The FTIR tests were performed at slice depths of 100μm for the shallow layer and 500μm for the deep layer. The test index was the change in carbonyl substituent index ΔI. 羰基 and the change in the substituent index of the benzene ring ΔI 苯环 .

[0051] To verify the rationality of the curve m obtained from this type of asphalt, another group of asphalt was placed in an aging chamber for light exposure, followed by light protection. The light exposure time was T. 光照 =480h, light-avoidance time T 避光 =960h. MSCR tests were conducted at different time points during the light-shielding period, with test time points T1=0h, T2=240h, and T3=960h; corresponding to k4=0, k5=1 / 2, and k6=2. The test index selected was the irreversible creep compliance rate J. nr-diff , which will be referred to as ΔJ from now on.

[0052] The test results are shown in Tables 1 and 2: Table 1

[0053] Table 2

[0054] The FTIR test results were curve-fitted, with k as the horizontal axis and ΔI as the vertical axis. 苯环 and ΔI 羰基The fitted function is an exponential function, and the result is as follows: Figure 2 , 3 As shown.

[0055] The MSCR test results were curve-fitted, with k as the x-axis and ΔJ as the y-axis. The fitting function was an exponential function, and the results are as follows: Figure 4 As shown.

[0056] The results of the MSCR test and infrared detection are analyzed as follows: like Figure 2 As shown, the selected index is ΔI. 苯环 When the slice depth is selected as a shallow layer of 100 μm, ΔI 苯环 The curve gradually increases with increasing k value, indicating it is an increasing function, but its increasing trend gradually decreases, meaning the curve is a convex function; when the slice depth is selected as a deep layer of 500 μm, ΔI 苯环 The curve first increases and then decreases as the value of k increases; the first half of the curve function is an increasing function, and the second half is a decreasing function.

[0057] like Figure 3 As shown, the selected index is ΔI. 羰基 When the slice depth is selected as a shallow layer of 100 μm, ΔI 羰基 As the value of k increases, it first increases and then slightly decreases; the first half of the curve function is an increasing function, and the second half is a decreasing function; when the slice depth is selected as a deep layer of 500 μm, ΔI 羰基 As the value of k increases, the curve first increases sharply and then decreases sharply. The first half of the curve function is an increasing function, and the second half is a decreasing function.

[0058] The fitted curve of the rate of change of irreversible creep compliance is as follows: Figure 4 As shown, ΔJ gradually increases with the value of k, and the curve function is an increasing function. At the same time, the increasing trend is gradually decreasing, and the curve function is a convex function.

[0059] As shown above, when the shallow layer of 100 μm is selected, and the index is the benzene ring substituent index, the fitting curve of the rate of change of irreversible creep compliance and ΔI are obtained. 苯环 The fitted curves exhibit consistent functional increasing / decreasing properties and concavity / convexity, showing good correlation. Plotting k as the abscissa, the values ​​at the ΔI at a depth of 100 μm are respectively... 苯环 Using ΔJ as the ordinate, curve fitting was performed on each axis, and a dual Y-axis graph was plotted. The results are as follows: Figure 5 As shown, the change in the benzene ring index, i.e., the amount of diffused benzene ring substituents, with respect to the value of k is highly consistent with the trend of ΔJ over time. In other words, the degree of aging of Z90# asphalt is well correlated with the degree of diffusion. Therefore, a shallow layer of 100 μm with ΔJ is selected. 苯环It can be used to characterize the UV aging resistance of Z90# asphalt, and is more accurate.

[0060] Q70# asphalt: Two groups of Q70# asphalt were placed in an aging chamber for testing. The test time axis was the same as that of Z90# asphalt. Figure 1 As shown, the test indicators are the same as those for Z90# asphalt.

[0061] The test results are shown in Tables 3 and 4: Table 3

[0062] Table 4

[0063] The FTIR test results were curve-fitted, with k as the horizontal axis and ΔI as the vertical axis. 苯环 and ΔI 羰基 The fitted function is an exponential function, and the result is as follows: Figure 6 , 7 As shown.

[0064] The MSCR test results were curve-fitted, with k as the x-axis and ΔJ as the y-axis. The fitting function was an exponential function, and the results are as follows: Figure 8 As shown.

[0065] The results of the MSCR test and infrared detection are analyzed as follows: like Figure 6 As shown, the selected index is ΔI. 苯环 When the slice depth is selected as a shallow layer of 100 μm, ΔI 苯环 The curve gradually increases with increasing k value, indicating it is an increasing function, but its increasing trend gradually decreases, meaning the curve is a convex function; when the slice depth is selected as a deep layer of 500 μm, ΔI 苯环 The function first decreases and then increases as the value of k increases; the first half of the function is decreasing and the second half is increasing.

[0066] like Figure 7 As shown, the selected index is ΔI. 羰基 When the slice depth is selected as a shallow layer of 100 μm, ΔI 羰基 The value of ΔI gradually increases with increasing k, and the curve is an increasing function, but its increasing trend is gradually increasing, that is, the curve is a concave function; when the slice depth is selected as a deep layer of 500 μm, ΔI 羰基 The function first decreases and then increases as the value of k increases; the first half of the function is decreasing and the second half is increasing.

[0067] The fitted curve of the rate of change of irreversible creep compliance is as follows: Figure 8As shown, ΔJ gradually increases with the value of k, and the curve function is an increasing function. At the same time, the increasing trend is gradually decreasing, and the curve function is a convex function.

[0068] When a shallow layer of 100 μm is selected, and the index is the benzene ring substituent index, the fitted curve of the rate of change of irreversible creep compliance and ΔI are obtained. 苯环 The fitted curves exhibit consistent functional increasing / decreasing properties and concavity / convexity, showing good correlation. Plotting k as the abscissa, the values ​​at the ΔI at a depth of 100 μm are respectively... 苯环 Using ΔJ as the ordinate, curve fitting was performed on each axis, and a dual Y-axis graph was plotted. The results are as follows: Figure 9 As shown. It can be observed that the change in the benzene ring index, i.e., the amount of diffused benzene ring substituents, with respect to the value of k is highly consistent with the trend of ΔJ with respect to the value of k. That is to say, Q70 # The degree of asphalt aging correlates well with the degree of its diffusion. Therefore, shallow ΔI is selected. 苯环 It can be used to characterize Q70. # The ability of asphalt to resist ultraviolet aging is more accurate.

[0069] Combining the test results of the two types of asphalt, it can be found that in the infrared spectroscopy experiment, when the benzene ring index of the shallow layer (100μm) is selected as the fitting parameter, its fitting curve has a good correlation with the fitting curve of ΔJ in the MSCR experiment. However, when the deep layer (500μm) or the carbonyl index (shallow and deep layers) is selected as the index, the correlation of the fitting curve is poor.

[0070] Plot the value of k on the x-axis and the ΔI of the two types of asphalt on the y-axis. 苯环 Using ΔJ as the ordinate, curve fitting is performed respectively, as follows: Figure 10 , Figure 11 As shown, in the MSCR test, the ΔJ of asphalt increases continuously with the increase of k value, but the increasing trend gradually decreases; in the infrared spectroscopy test, the diffusion of benzene ring index also increases continuously with the increase of k value, but the increasing trend gradually decreases.

[0071] In the MSCR test, the ΔJ of Z90# asphalt was consistently greater than that of Q70# asphalt, while in the infrared spectroscopy test, the ΔI of Z90# asphalt was greater. 苯环 It is always greater than Q70# asphalt.

[0072] Therefore, it can be proven that the UV aging resistance of the two types of asphalt under the same light conditions is related to their diffusion capacity.

[0073] Based on the above experiments, the different UV aging resistance exhibited by asphalt under different conditions, especially under different light and dark conditions, is due to the differences in its diffusion capacity.

[0074] Therefore, this invention can compare the diffusion capabilities of different types of asphalt by measuring their diffusion rates under different light-shielding times, and thus compare their resistance to ultraviolet aging.

[0075] Calculate the two types of asphalt when k 平均 The diffusion rate of the benzene ring substituent at =3 / 2 is: V of Z90# asphalt 扩散 =0.0076d -1 V of Q70# asphalt 扩散 =0.0045d -1 .

[0076] Therefore, in region A, Q70# asphalt has better resistance to ultraviolet aging, and Q70# asphalt should be selected for actual engineering projects.

[0077] Example 2 Adding a certain amount of aromatic oil to low-grade asphalt can transform it into other high-grade asphalts. Taking K70# asphalt as an example, the following experiment was conducted: Three types of blended asphalt were prepared by adding 5%, 10%, and 15% aromatic oil to K70# asphalt (corresponding to the 5%, 10%, and 15% additives described below, respectively). The experiments for these three types of blended asphalt were conducted according to the method in Example 1. The light exposure duration was 24 hours, and the light avoidance duration was 48 hours. The light avoidance time points were selected as 0 hours, 24 hours, and 48 hours of light avoidance, with corresponding k values ​​of 0, 1, and 2. The light exposure temperature was 60℃, the light avoidance temperature was 20℃, and the light intensity was 11000 μw / cm². 2 FTIR testing was performed at a slice depth of 100 μm, and the test index was the change in the benzene ring substituent index ΔI. 苯环 The experimental results are shown in Table 5: Table 5

[0078] ΔI 苯环 Fit to the k value, such as Figure 12 At each doping level, ΔI increases with increasing k value. 苯环 All values ​​increase, indicating a gradual deepening of aging. However, the increasing trend gradually decreases rather than continuously increasing, consistent with the pattern observed in Z90# and Q70# asphalt. Adding aromatic oil to the base asphalt can transform it from a low-grade to a high-grade asphalt. This pattern is observed at all three admixture levels, therefore, this pattern is not limited to the base asphalt used in the embodiments of this invention.

[0079] Therefore, in this invention, shallow ΔI is selected. 苯环 It can be used to characterize the UV aging resistance of various asphalts.

[0080] In the MSCR test, the J of the asphalt nr-diff All of them increase continuously with the increase of k value, but the increasing trend is gradually decreasing; in infrared spectroscopy, the diffusion of benzene ring index also increases continuously with the increase of k value, but the increasing trend is gradually decreasing.

[0081] Based on the above experiments, the different UV aging resistance exhibited by asphalt under different conditions, especially under different light and dark conditions, is due to the differences in its diffusion capacity.

[0082] Therefore, this invention can compare the diffusion capacity, that is, the resistance to ultraviolet aging, of different types of asphalt by measuring their diffusion rate under different conditions.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for testing the UV aging resistance of asphalt, characterized in that, Includes the following steps: (1) Based on the climate data of the application area, determine the average daily night-day length ratio k of the area. 平均 Daytime high temperature C 光 The highest temperature at night is C 黑 and daily average radiation intensity P 平均 ; (2) The asphalt to be tested was placed in an aging chamber for light exposure, and then immediately protected from light; the light exposure time of the asphalt was t. 光照 And the time of light avoidance is t 避光 The temperature of the asphalt during sunlight exposure is the highest daytime temperature C. 光 The light intensity is P, and the light-avoidance temperature during the light-avoidance period is the highest nighttime temperature C. 黑 Where P = N × P 平均 N is the light intensity amplification factor, 3≤N≤5; (3) At different time points t during the period from the start to the end of light avoidance. i Infrared spectroscopy was performed on samples of the asphalt to be tested at depths ranging from 50 μm to 150 μm below the asphalt surface. The change in the benzene ring substituent index was calculated to obtain t. i The ratio of the dark time of sample i at time k i and the corresponding change in the benzene ring substituent index ΔI i where i is a positive integer; Establish a rectangular coordinate system, with the dark time ratio k as the abscissa and the change in the benzene ring substituent index ΔI as the ordinate. 苯环 Using the vertical coordinate as the ordinate, construct several points M in the rectangular coordinate system. i (k) i ΔI i ), for the aforementioned points M i (k) i ΔI i Curve fitting is performed to obtain curve m; (4) Calculate using curve m when k takes the value k 平均 At that time, the average change in the benzene ring substituent index ΔI 平均 ; (5) From the aforementioned ΔI 平均 Calculate the diffusion rate V 扩散 ; (6) Using the diffusion rate V 扩散 V represents the resistance of the asphalt to ultraviolet aging under the climatic conditions of the application area. 扩散 The larger the value, the worse the resistance of the asphalt to ultraviolet aging in the application area.

2. The test method for the UV aging resistance of asphalt according to claim 1, characterized in that, When the asphalt to be tested is base asphalt, t 光照 ≥72h; when the asphalt to be tested is blended asphalt, t 光照 ≥24h.

3. The test method for the UV aging resistance of asphalt according to claim 1 or 2, characterized in that, t 光照 ≤t 避光 ≤2t 光照 。 4. The test method for the UV aging resistance of asphalt according to any one of claims 1 to 3, characterized in that, include: k i =t i / t 光照 。 5. The test method for the UV aging resistance of asphalt according to any one of claims 1 to 4, characterized in that, include: The point M i (k) i ΔI i The change in the benzene ring substituent index ΔI i The calculation formula is: ΔI i =|I i -I0|, where I i The time for avoiding light is t. i The benzene ring substituent index is obtained by infrared spectroscopy testing of samples taken at specific time points. I0 represents the benzene ring substituent index obtained by infrared spectroscopy testing of unexposed asphalt.

6. The test method for the UV aging resistance of asphalt according to any one of claims 1 to 5, characterized in that, The curve fitting method includes: the curve m consists of at least 3 different time points t. i The measured values ​​were obtained by curve fitting, the fitting function was an exponential function, and the fitting correlation coefficient R was... 2 ≥95%.

7. The test method for the UV aging resistance of asphalt according to claim 6, characterized in that, include: The curve m passes through three points with coordinates M1(k1, ΔI1), M2(k2, ΔI2), and M3(k3, ΔI3), corresponding to light-shielding times of the sampling tests t1, t2, and t3, respectively, and satisfies: 0 < t1 < t2 < t3 ≤ t 避光 .

8. The test method for the UV aging resistance of asphalt according to any one of claims 1 to 7, characterized in that, include: Any two adjacent points M on curve m i With point M i+1 The interval is not less than 1 / 5t 光照 .

9. The test method for the UV aging resistance of asphalt according to any one of claims 1 to 8, characterized in that, The V 扩散 The calculation formula is: V 扩散 =ΔI 平均 / (t) 光照 +k 平均 ×t 光照 ).

10. The application of the test method for the UV aging resistance of asphalt according to any one of claims 1 to 9, characterized in that, include: Using asphalt #1 as the asphalt to be tested, its curve m was obtained. 1# Using curve m 1# Get V 扩散1 ; Using asphalt #2 as the asphalt to be tested, its curve m was obtained. 2# Using curve m 2# Get V 扩散2 ; If the diffusion rate V corresponding to asphalt #1 扩散1 The diffusion rate V is greater than that of asphalt #2. 扩散2 If the UV aging resistance of asphalt 1# is weaker than that of asphalt 2#, then the UV aging resistance of asphalt 1# is stronger than that of asphalt 2#.

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