Evaluation method and system for aging degree of rubber powder modified asphalt and storage medium

Abstract

The invention discloses a rubber powder modified asphalt aging degree evaluation method and system and a storage medium, and belongs to the technical field of road engineering. The evaluation method comprises the following steps: respectively preparing rubber powder modified asphalt before and after aging into film samples, observing the microstructure, dividing the film samples into three subareas before and after aging according to the microstructure result, and carrying out infrared scanning on the three subareas before and after aging to obtain infrared spectrograms of the three subareas before and after aging, calculating functional group indexes of the characteristic peaks of the three partitions before and after aging according to the characteristic peaks of the three partitions before and after aging; calculating to obtain the functional group index growth ratio of the three partitions; and evaluating the aging degree of the rubber powder modified asphalt according to the functional group index growth ratio of the three partitions and the specific gravity of the three partitions. According to the method, the aging degree of each phase state and the contribution to the overall aging in the aging process are determined from the perspective of multiple phase states, and the complex aging behavior of the rubber powder modified asphalt is accurately evaluated.

Description

Technical Field

[0001] The present invention relates to the technical field of road engineering, and more particularly to a method, system and storage medium for evaluating the aging degree of crumb rubber modified asphalt. Background Art

[0002] The aging of crumb rubber modified asphalt will lead to a decrease in the tensile strength of the asphalt pavement, making it prone to cracks; and the generation of cracks greatly increases the risk of rainwater infiltrating into the pavement structure, and once the water infiltrates, it will cause damage to the pavement structure. In addition, the adhesion of asphalt materials will gradually decay with aging, causing the asphalt film to peel off from the surface of the aggregate, ultimately leading to pavement diseases such as looseness and potholes. Therefore, accurately characterizing the aging behavior of asphalt materials and clarifying its aging mechanism are the basis for improving the anti-aging performance of asphalt materials or delaying asphalt aging, and are of great significance for the development of long-life pavements.

[0003] In the existing characterization methods, Fourier transform infrared spectroscopy is used to characterize the changes in chemical structure during the aging process of crumb rubber modified asphalt. By comparing the infrared spectra of asphalt samples before and after aging, the changes in functional groups in the samples can be found, so as to judge the influence of aging on the molecular structure of crumb rubber modified asphalt. Fluorescence microscopy, atomic force microscopy and scanning electron microscopy are used to characterize the changes in microtopography during the aging process of crumb rubber modified asphalt. By comparing the micrographs of crumb rubber modified asphalt before and after aging, the changes in crumb rubber particles in the samples can be observed, so as to judge the influence of aging on the microtopography of crumb rubber modified asphalt. However, the composition of crumb rubber modified asphalt is complex, resulting in asphalt oxidation, crumb rubber swelling and degradation, and material interaction between asphalt and crumb rubber during its aging process. Fourier transform infrared spectroscopy can only obtain the overall infrared spectrum of the sample and cannot distinguish the changes in the molecular structure of different phases; the microscopic method can only observe the changes in the microtopography of the sample and has no knowledge of the molecular structure changes brought about by the changes in the microtopography of each phase. Summary of the Invention

[0004] In view of the above problems, the present invention provides a method, system and storage medium for evaluating the aging degree of crumb rubber modified asphalt. When analyzing the aging behavior of crumb rubber modified asphalt, the present invention determines the aging degree of each component phase and its contribution to the overall aging during the aging process of crumb rubber modified asphalt from the perspective of multiple phases, accurately evaluates the complex aging behavior of crumb rubber modified asphalt, and provides targeted positioning for the anti-aging and regeneration research of crumb rubber modified asphalt.

[0005] The first object of the present invention is to provide a method for evaluating the aging degree of crumb rubber modified asphalt, comprising the following steps: Prepare the crumb rubber modified asphalt before aging into a film sample before aging, observe the microscopic morphology of the film sample before aging, and divide it into three pre-aging zones according to the microscopic morphology results, namely the asphalt zone before aging, the crumb rubber zone before aging, and the interaction zone of asphalt and crumb rubber before aging.

[0006] Perform infrared scanning on the three pre-aging zones to obtain the infrared spectra of the three pre-aging zones, and calculate the characteristic peak functional group indices of the three pre-aging zones based on the characteristic peaks in the infrared spectra.

[0007] The test method for the crumb rubber modified asphalt after aging is the same as the operation method for the crumb rubber modified asphalt before aging, and the characteristic peak functional group indices of the three zones after aging are obtained; the test method for the crumb rubber modified asphalt after aging is as follows: Prepare the crumb rubber modified asphalt after aging into film samples after aging respectively, use the microscopic system of the infrared microscope to observe the microscopic morphology of the film samples, and divide them into three zones after aging according to the microscopic morphology results, namely the asphalt zone after aging, the crumb rubber zone after aging, and the interaction zone of asphalt and crumb rubber after aging.

[0008] Perform infrared scanning on the three zones after aging to obtain the infrared spectra of the three zones after aging, and calculate the characteristic peak functional group indices of the three zones after aging based on the characteristic peaks in the infrared spectra.

[0009] Calculate the growth ratio of the functional group indices of the three zones based on the characteristic peak functional group indices of the three zones before aging and the characteristic peak functional group indices of the three zones after aging.

[0010] Evaluate the aging degree A of the crumb rubber modified asphalt based on the growth ratio of the functional group indices of the three zones and the proportion of the three zones.

[0011] 0 ≤ A ≤ 8, the crumb rubber modified asphalt is in the initial stage of aging; 8 < A ≤ 15, the crumb rubber modified asphalt is in the middle stage of aging; A > 15, the crumb rubber modified asphalt is in the late stage of aging.

[0012] The present invention evaluates the aging degree of crumb rubber modified asphalt based on multiple phases. The multiple phases refer to the changes in asphalt, the changes in crumb rubber, and the material interaction behavior between the two during the aging process of crumb rubber modified asphalt. The present invention combines an optical microscope and a Fourier transform infrared spectrometer, performs infrared scanning on a selected area of the crumb rubber modified asphalt to obtain the infrared spectrum of the selected area, and then studies the selected area. The selected area is usually from dozens of micrometers to several millimeters. It should be noted that the present invention can select an instrument that has both the functions of microscopic morphology testing and infrared testing for testing, or use an instrument equipped with microscopic morphology testing for testing and then use an instrument equipped with infrared testing for testing. If two instruments are selected for testing respectively, the sample testing points should correspond precisely.

[0013] In the present invention, the aged crumb rubber modified asphalt can be prepared by artificial aging or extracted from natural aging specimens. When using the artificial aging method for preparation, for example, simulation tests are carried out through a thermal, light and water coupling aging chamber.

[0014] In a preferred embodiment of the present invention, the calculation formula for the aging degree A is: A = growth ratio of asphalt zone functional group index × proportion of asphalt zone + growth ratio of crumb rubber zone functional group index × proportion of crumb rubber zone + growth ratio of asphalt and crumb rubber interaction zone functional group index × proportion of asphalt and crumb rubber interaction zone.

[0015] In a preferred embodiment of the present invention, the calculation formula for the proportion of the three zones is: .

[0016] .

[0017] .

[0018] In a preferred embodiment of the present invention, the asphalt zone is a homogeneous phase region in the microscopic morphology.

[0019] The crumb rubber zone is a granular phase region in the microscopic morphology.

[0020] The asphalt and crumb rubber interaction zone is an interaction region of homogeneous phase and granular phase in the microscopic morphology.

[0021] In a preferred embodiment of the present invention, the characteristic peak of the asphalt zone is the sulfoxide group peak.

[0022] The characteristic peak of the crumb rubber zone is the trans-olefin peak.

[0023] The characteristic peak of the asphalt and crumb rubber interaction zone is the silica peak.

[0024] In a preferred embodiment of the present invention, the functional group index of the characteristic peak of the asphalt zone is the ratio of the area of the sulfoxide group peak to the area of the reference peak; the calculation formula for the functional group index of the characteristic peak of the asphalt zone is: ; where I SU is the sulfoxide index, A 1031 is the area of the sulfoxide group peak, A 1376 is the area of the reference peak.

[0025] The functional group index of the characteristic peak of the crumb rubber zone is the ratio of the area of the trans-olefin peak to the area of the reference peak.

[0026] The calculation formula for the functional group index of the characteristic peaks in the rubber powder partition is as follows: ; Among them, I PB is the butadiene index, A 965 is the area of the trans-olefin peak, A 1376 is the area of the reference peak.

[0027] The functional group index of the characteristic peaks in the interaction partition of asphalt and rubber powder is the ratio of the area of the silica peak to the area of the reference peak.

[0028] The calculation formula for the functional group index of the characteristic peaks in the interaction partition of asphalt and rubber powder is as follows: ; Among them, I Si-O-Si is the siloxane index, A 1100 is the area of the silica peak, A 1376 is the area of the reference peak.

[0029] The reference peak is the methyl umbrella vibration peak at 1376 cm -1 position.

[0030] In a preferred embodiment of the present invention, the calculation formula for the growth ratio of the functional group index is as follows: .

[0031] In a preferred embodiment of the present invention, the thin film sample before aging is prepared by a solution method or a cryosection method.

[0032] The preparation method of the solution method includes the following steps: Dissolve the rubber powder modified asphalt before aging in trichloroethylene solution and shake well to obtain a mixed solution, then add the mixed solution to a potassium bromide tablet, and obtain a thin film sample after the trichloroethylene volatilizes.

[0033] The preparation method of the cryosection method includes the following steps: Immerse the rubber powder modified asphalt before aging with an embedding medium, and cut the embedding medium into a solid state to obtain a thin film sample before aging. Specifically, immerse 0.1 g of rubber powder aged asphalt with an embedding medium, then place it in an environment of -12 °C. After the embedding medium cools into a solid state, place it on a cryostat, select the section thickness parameter to be 30 μm - 50 μm, and then cut to obtain a thin film sample.

[0034] The preparation method of the thin film sample after aging is the same as that of the thin film sample before aging.

[0035] The second object of the present invention is to provide an evaluation system for the aging degree of the crumb rubber modified asphalt, which is used to execute the steps in the evaluation method for the aging degree of the crumb rubber modified asphalt. The evaluation system includes a data acquisition module, a data processing module, a data calculation module, and an evaluation module.

[0036] The data acquisition module is used for infrared scanning to obtain an infrared spectrogram.

[0037] The data processing module is used to calculate the characteristic peak functional group index according to the infrared spectrogram.

[0038] The data calculation module is used to combine the characteristic peak functional group index to obtain the growth ratio of the functional group index in three zones. After multiplying the growth ratio of the functional group index in the three zones by the respective proportions of the three zones and then summing them up, a comprehensive index is obtained.

[0039] The evaluation module is used to use the comprehensive index as an aging degree evaluation index to evaluate the multi-phase state aging degree of the crumb rubber modified asphalt.

[0040] The third object of the present invention is to provide a storage medium, on which a computer program is stored. The computer program is executed by a processor to implement the steps of the evaluation method for the aging degree of the crumb rubber modified asphalt.

[0041] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides an evaluation method for the aging degree of the crumb rubber modified asphalt. The infrared microscopic system can synchronously characterize the changes in the microscopic morphology and chemical structure during the aging process of the crumb rubber modified asphalt, realize non-physical phase separation, and analyze the changes in each phase state during the aging process of the crumb rubber modified asphalt from the multi-phase state perspective, so as to evaluate the aging behavior of the crumb rubber modified asphalt more accurately and objectively.

[0042] The method of the present invention avoids physical phase separation of the crumb rubber modified asphalt, reduces the test difficulty, overcomes the defect that the existing characterization methods cannot perform multi-phase state synchronous characterization, and analyzes the influence of the changes in asphalt, the changes in crumb rubber, and the material interaction behavior between the two on its aging behavior during the aging process of the crumb rubber modified asphalt. Description of the Drawings

[0043] Figure 1 It is a schematic diagram for calculating the peak areas of different functional groups of the present invention.

[0044] Figure 2 It is a microscopic image and an infrared spectrogram of the asphalt zone of the crumb rubber modified asphalt aged for 2 days according to the present invention. Among them, (a) is the microscopic image, and (b) is the infrared spectrogram obtained by scanning the points in the asphalt zone A in (a).

[0045] Figure 3 The microscopic image and infrared spectrum of the rubber powder partition in the rubber powder modified asphalt aged for 2 days according to the present invention, wherein (a) is the microscopic image, and (b) is the infrared spectrum obtained by scanning the rubber powder partition at point A in (a).

[0046] Figure 4 The microscopic image and infrared spectrum of the interaction partition between asphalt and rubber powder in the rubber powder modified asphalt aged for 2 days according to the present invention, wherein (a) is the microscopic image, and (b) is the infrared spectrum obtained by scanning the interaction partition between asphalt and rubber powder at point A in (a).

[0047] Figure 5 The schematic diagram of the sulfoxide index of the asphalt partition in the rubber powder modified asphalt samples with different aging times in Example 1 of the present invention.

[0048] Figure 6 The schematic diagram of the butadiene index of the rubber powder partition in the rubber powder modified asphalt samples with different aging times in Example 1 of the present invention.

[0049] Figure 7 The schematic diagram of the silicon-oxygen index of the interaction partition in the rubber powder modified asphalt samples with different aging times in Example 1 of the present invention.

[0050] Figure 8 The schematic diagram of the change trend of each functional group index and the change trend of the complex modulus in the rubber powder modified asphalt samples with different aging times in Example 1 of the present invention, wherein (a) is the schematic diagram of the change trend of each functional group index, and (b) is the schematic diagram of the change trend of the complex modulus. Detailed implementation manners

[0051] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0052] The rubber powder used in the present invention is 40-mesh ordinary radial waste tire rubber powder, purchased from Chongqing Jiuxianghua Big Rubber Technology Co., Ltd., and the SBS modifier used is YH-791H linear SBS modifier, purchased from Baling Petrochemical Co., Ltd.

[0053] Example 1 This example discloses a method for evaluating the aging degree of rubber powder modified asphalt, as Figure 1 shown, the specific steps are as follows: S1. The preparation method of the rubber powder modified asphalt is as follows: First, mix 15 parts of rubber powder with 85 parts of Jingbo 70# matrix asphalt and stir at 200 °C for 6 h; then adjust the preparation temperature to 180 °C, add 2 parts of SBS modifier and stir for another 1.5 h; finally, keep the preparation temperature at 180 °C, add 0.2 parts of sulfur and stir for 1 h to obtain the rubber powder modified asphalt.

[0054] Carry out indoor simulation tests on the thermal, light, and water coupling aging of the rubber powder modified asphalt. The operation steps are as follows: Heat the rubber powder modified asphalt at 163 °C for 0.5 h to make the asphalt in a flowing state; then accurately weigh 20 g of the sample with a film thickness of 1000 μm and pour it into a standard aging pan with a diameter of 14 cm. After spreading the rubber powder modified asphalt in the standard aging pan evenly, put it into the coupling aging box; adjust the test temperature of the coupling aging box to 60 °C and the humidity to 66%, and turn on the high-pressure mercury lamp to start the coupling aging test; in order to ensure uniform illumination, adjust the position of the aging pan every 24 h.

[0055] Take 0.2 g of samples aged for 0 days, 2 days, 4 days, 8 days, and 16 days respectively, dissolve them in 3 mL of trichloroethylene and shake well, and then drop the mixed solution on a potassium bromide tablet to obtain different thin film samples.

[0056] It should be noted that the sample obtained by aging for 0 days is the thin film sample before aging, denoted as FH-0d, and the samples obtained by aging for 2 days to 16 days are the thin film samples after aging with different degrees of aging, denoted as FH-2d, FH-4d, FH-8d, and FH-16d respectively.

[0057] S2. Use the microscopic system of the infrared microscope to observe the microscopic morphology of the thin film sample before aging, and divide it into three pre-aging zones according to the microscopic morphology results, namely the asphalt zone before aging, the rubber powder zone before aging, and the interaction zone of asphalt and rubber powder before aging. Conduct infrared scanning on the three pre-aging zones to obtain the infrared spectra of the three pre-aging zones, and calculate the characteristic peak functional group indices of the three pre-aging zones based on the characteristic peaks in the infrared spectra.

[0058] Treat the rubber powder modified asphalt after aging with reference to the above method to obtain the characteristic peak functional group indices of the three zones after aging.

[0059] Specifically, use the microscopic system of the infrared microscope to observe the microscopic morphology of the thin film sample after aging, and divide it into three post-aging zones according to the microscopic morphology results, namely the asphalt zone after aging, the rubber powder zone after aging, and the interaction zone of asphalt and rubber powder after aging. Conduct infrared scanning on the three post-aging zones to obtain the infrared spectra of the three post-aging zones, and calculate the characteristic peak functional group indices of the three post-aging zones based on the characteristic peaks in the infrared spectra.

[0060] Specifically, different thin film samples are placed on the stage of the instrument, and the instrument is adjusted to make the transmission light source pass through the thin film sample; then the parameters are set on the computer, and different regions are determined under the microscopic image; the different regions determined under the microscopic image are: selecting the homogeneous phase as the asphalt region; selecting the granular phase as the rubber powder region; selecting the interaction region of the homogeneous phase and the granular phase as the asphalt-rubber powder interaction region. Finally, the determined regions are scanned to obtain the infrared spectrogram of the corresponding region.

[0061] The calculation formula for the functional group index that can represent the change of the asphalt region is: ; Among them, I SU is the sulfoxide index, A 1031 is the sulfoxide group peak area, A 1376 is the reference peak area.

[0062] The calculation formula for the functional group index that can represent the change of the rubber powder region is: ; Among them, I PB is the butadiene index, A 965 is the trans-olefin peak area, A 1376 is the reference peak area.

[0063] The calculation formula for the functional group index that can represent the change of the interaction region is: ; Among them, I Si-O-Si is the siloxane index, A 1100 is the silica peak area, A 1376 is the reference peak area.

[0064] It should be noted that during the aging study, both the characteristic peak and the reference peak are affected by factors such as sample thickness and concentration, but only the characteristic peak is affected by aging. The characteristic index obtained by dividing the two only reflects the aging effect. The reference peak generally selects a peak that is less affected by aging. In the present invention, the methyl umbrella vibration at 1376 cm -1 is used as the reference peak.

[0065] It should be noted that the integral range of the functional groups in the asphalt sample is the same, and the calculation of the peak areas of different functional groups is as Figure 1As shown, the peak area integration function built into Origin software is used for calculation. The integration ranges of different functional groups are as follows: 965 cm -1 The integration range of the butadiene group at this position is 929.7 cm -1 ~979.8 cm -1 .

[0066] 1031 cm -1 The integration range of the sulfoxide group at this position is 981.7 cm -1 ~1045.3 cm -1 .

[0067] 1100 cm -1 The integration range of the siloxy group at this position is 1045.3 cm -1 ~1139.9 cm -1 .

[0068] 1376 cm -1 The integration range of the CH3 symmetric bending group at this position is 1325.1 cm -1 ~1392.6 cm -1 .

[0069] S3. Calculate the growth ratios of the functional group indices of the three zones based on the functional group indices of the characteristic peaks in the three zones before aging and those in the three zones after aging.

[0070] .

[0071] S4. Evaluate the aging degree of the crumb rubber modified asphalt based on the growth ratios of the functional group indices of the three zones and the proportions of the three zones.

[0072] .

[0073] .

[0074] .

[0075] The calculation formula for the aging degree A is as follows: A = Growth ratio of the functional group index of the asphalt zone × Proportion of the asphalt zone + Growth ratio of the functional group index of the crumb rubber zone × Proportion of the crumb rubber zone + Growth ratio of the functional group index of the asphalt-crumb rubber interaction zone × Proportion of the asphalt-crumb rubber interaction zone.

[0076] In this embodiment, taking the evaluation of the multi-phase aging degree of crumb rubber modified asphalt aged by the coupling of light, heat and water at different times as an example, the implementation effect of the present invention is illustrated. A total of five crumb rubber modified asphalt samples with different aging times are selected, which are aged for 0 days, 2 days, 4 days, 8 days, and 16 days respectively, and are defined as FH-0d, FH-2d, FH-4d, FH-8d, and FH-16d respectively. The change rate of the macroscopic properties of the asphalt samples decreases with the increase of the aging time. Therefore, the change rate of each phase should also decrease with the increase of the aging time. Based on the method proposed by the present invention, the multi-phase aging behavior of crumb rubber modified asphalt can be characterized and compared with the change trend of macroscopic properties, which can further verify the reliability of the method of the present invention.

[0077] The microscopic images of each phase and the infrared spectrogram of crumb rubber modified asphalt aged for 2 days are as Figures 2 to 4 shown. Figure 2 The (b) in Figure 2 is the infrared spectrogram obtained from the scanning point of the asphalt partition at point A in (a) of Figure 3 The (b) in Figure 3 is the infrared spectrogram obtained from the scanning point of the asphalt partition at point A in (a) of Figure 4 The (b) in Figure 4 is the infrared spectrogram obtained from the scanning point of the asphalt partition at point A in (a) of Figure 5 shown. Then, using Origin software, the peak area of the representative peak of the infrared spectra of different partitions is calculated, and the functional group index that can represent the changes of different partitions is obtained. The schematic diagram of the sulfoxide index of the asphalt micro-region of crumb rubber modified asphalt samples with different aging times is as

[0078] shown. It can be seen from 0d to 2d that the increase of the sulfoxide index is not obvious, indicating that although asphalt oxidation occurs in this stage, it is not intense; from 2d to 4d, the increase of the sulfoxide index is the most obvious, indicating that the asphalt oxidation reaction is intense in this stage; from 4d to 8d, the increase amplitude of the sulfoxide index becomes smaller, indicating that the oxidation reaction begins to weaken; in the end, from 8d to 16d, the aging time increases significantly, while the sulfoxide index hardly changes, indicating that the asphalt phase hardly undergoes oxidation reaction in the later stage of aging.

[0078] The schematic diagram of the butadiene index of the crumb rubber micro-region of crumb rubber modified asphalt samples with different aging times is as Figure 6 shown. Through semi-quantitative comparison, it can be found that in the initial stage of aging from 0d to 2d, the butadiene index of the crumb rubber increases significantly, indicating that the crumb rubber degrades in the early stage of aging of the crumb rubber modified asphalt; during 2d to 4d, the butadiene index of the crumb rubber micro-region increases significantly, indicating that the crumb rubber degrades violently in this stage; as the aging time continues to increase, from 4d to 8d and 8d to 16d, the increase of the butadiene index in the crumb rubber micro-region is very slow, indicating that the degradation of the crumb rubber has been basically completed in the later stage of aging, and further increasing the aging time has little effect on the degradation of the crumb rubber.

[0079] Schematic diagram of the interactive micro-region silicon-oxygen index of crumb rubber modified asphalt samples with different aging times is as follows Figure 7 As shown, from the change of the silicon-oxygen index, it can be found that the silicon-oxygen index of crumb rubber modified asphalt is basically 0 before aging, indicating that there is no material interaction between the crumb rubber and asphalt phases in crumb rubber modified asphalt before surface aging. However, during the process from 0d to 8d, the interaction reaction gradually occurs, and the silicon-oxygen index shows a linear increase with the increase of aging time. By the end of aging, the interaction reaction basically stops. This shows that the material interaction between asphalt and crumb rubber continues during the 0d - 8d stage, and the interaction reaction stops along with the cessation of the changes in asphalt and crumb rubber in the later stage.

[0080] Table 1 summarizes the aging performance indexes of crumb rubber modified asphalt with different aging times tested by conventional methods. It can be seen that the change rules of the aging indexes of each performance of crumb rubber modified asphalt are the same as those of the functional group indexes in each region, both changing violently during 0d - 4d and basically remaining unchanged in the later stage of aging. This further proves the reliability and rationality of the method proposed in the present invention.

[0081] Table 1 Results of Aging Performance Indexes

[0082] To further evaluate the aging degree of each phase state and the whole of crumb rubber modified asphalt, Table 2 calculates the growth ratio of the functional group indexes in each region of crumb rubber modified asphalt before and after aging and the proportion of each region. It can be seen that the most significant change after aging occurs in the interaction region, indicating that the aging degree of the interaction phase state is the largest. And from the overall aging degree, it can be seen that the aging degree of crumb rubber modified asphalt gradually deepens in the early stage of aging and basically remains unchanged in the later stage of aging, which is consistent with the change rule of the rheological properties, further proving the reliability and rationality of the aging degree evaluation method proposed in the present invention.

[0083] It should be noted that in crumb rubber modified asphalt, there are mainly asphalt phase state and crumb rubber phase state, and the interaction phase state is an interaction behavior between asphalt and crumb rubber. Therefore, here the interaction phase state is regarded as asphalt and crumb rubber, so the whole is 2 times of asphalt and crumb rubber.

[0084] Table 2 Results of Aging Degree of Different Samples

[0085] Table 2 shows the results of the aging degree of different samples. Considering the changes in all aging performances, it can be considered that when 0 ≤ A ≤ 8, the crumb rubber modified asphalt is in the initial stage of aging, and at this time, all phase states participate in the reaction, resulting in obvious changes in rheological properties; when 8 < A ≤ 15, the crumb rubber modified asphalt is in the middle stage of aging, and at this time, the reaction of all phase states is the most intense, resulting in the largest change in rheological properties in this stage; when A > 15, the crumb rubber modified asphalt is in the later stage of aging, and at this time, the reaction rate of all phase states drops sharply, and the change in rheological properties also tends to be gentle.

[0086] The aging evaluation method proposed by the present invention comprehensively considers the influence of each component phase state during the aging process of crumb rubber modified asphalt, and accurately judges the contribution of each phase state during the aging process, overcoming the shortcoming of the existing evaluation methods that cannot consider multi-phase state factors. It can accurately evaluate the complex aging behavior of crumb rubber modified asphalt and provide targeted positioning for the anti-aging and regeneration research of crumb rubber modified asphalt.

[0087] To illustrate the superiority of the method of the present invention by comparison, the present invention further calculated the change trend diagrams of the sulfoxide index, butadiene index, and silicon-oxygen index of the whole sample with the aging time according to the existing characterization method in "Rapid Analysis Method and Reliability Research of Asphalt Based on Infrared Spectroscopy" published by Chen Fei et al. in the 6th issue of the 38th volume in December 2022 in "Highway Traffic Technology", and compared them with the change trend of the complex modulus. The results are as Figure 8 shown. It can be seen that both the sulfoxide index and the butadiene index of the whole sample obtained by using the existing characterization method only changed from 0d to 2d and remained basically unchanged thereafter; while the silicon-oxygen index increased between 0d to 2d and 4d to 8d and did not change in other aging time periods. However, the change of the macroscopic properties during the aging process mainly occurred from 0d to 4d, which is inconsistent with the results obtained by the existing characterization method. Therefore, the existing characterization method cannot accurately judge the aging degree of crumb rubber modified asphalt.

[0088] It should be noted that the complex modulus was tested by using a dynamic shear rheometer according to the AASHTO MP1a-04 method, and the test temperature was 64°C.

[0089] In summary, the multi-phase state-based aging degree evaluation method of crumb rubber modified asphalt proposed by the present invention can accurately evaluate the aging degree of each phase state of crumb rubber modified asphalt and the overall aging degree of crumb rubber modified asphalt during the aging process, overcoming the shortcoming of the existing evaluation methods that cannot consider the influence of multi-phase states, and providing targeted positioning for the anti-aging and regeneration research of crumb rubber modified asphalt.

[0090] Example 2 This embodiment provides an evaluation system for the aging degree of crumb rubber modified asphalt, including a data acquisition module, a data processing module, a data calculation module, and an evaluation module. Among them: The data acquisition module is used for infrared scanning to obtain an infrared spectrogram. Specifically, the microscopic system of an infrared microscope is used for scanning to obtain three partitions before aging and three partitions after aging. The three partitions before aging are the asphalt partition before aging, the crumb rubber partition before aging, and the asphalt-crumb rubber interaction partition before aging. The three partitions after aging are the asphalt partition after aging, the crumb rubber partition after aging, and the asphalt-crumb rubber interaction partition after aging.

[0091] Infrared scanning is performed on the three partitions before aging and the three partitions after aging to obtain infrared spectrograms.

[0092] A data processing module, configured to calculate the characteristic peak functional group index according to the infrared spectrogram.

[0093] A data calculation module, configured to combine the characteristic peak functional group indexes to obtain the growth ratios of the functional group indexes of the three partitions. After multiplying the growth ratios of the functional group indexes of the three partitions by the respective proportions of the three partitions and then summing them up, a comprehensive index is obtained.

[0094] An evaluation module, configured to use the comprehensive index as an aging degree evaluation index to evaluate the multi-phase aging degree of the crumb rubber modified asphalt.

[0095] Embodiment 3 This embodiment provides a storage medium on which a computer program is stored. The storage medium can be a common storage device, such as a hard disk, a solid-state drive, a USB flash drive, or an optical disc. The computer program is executed by a processor to implement the steps of the method for evaluating the aging degree of the crumb rubber modified asphalt.

[0096] For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple. For related parts, reference can be made to the description in the method part.

[0097] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0098] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A method for evaluating the aging degree of rubber-modified asphalt, characterized in that: The following steps are involved: The rubber powder modified asphalt before aging was prepared into a pre-aging film sample, and the microscopic morphology of the pre-aging film sample was observed. According to the microscopic morphology results, it was divided into three partitions before aging, namely, the asphalt partition before aging, the rubber powder partition before aging, and the asphalt and rubber powder interactive partition before aging; Perform infrared scanning on the three partitions before aging to obtain infrared spectra of the three partitions before aging, and calculate characteristic peak functional group indexes of the three partitions before aging according to characteristic peaks of the three partitions before aging in the infrared spectra; The aged crumb rubber modified asphalt was treated according to the above method to obtain the characteristic peak functional group index of the three partitions after aging; The functional group index growth ratio of the three partitions is calculated based on the functional group index of the characteristic peaks of the three partitions before aging and the functional group index of the characteristic peaks of the three partitions after aging; The aging degree A of the crumb rubber modified asphalt is evaluated based on the functional group index growth ratio of the three partitions and the specific gravity of the three partitions; 0≤A≤8, the rubber powder modified asphalt is in the early stage of aging; 8<A≤15, the rubber powder modified asphalt is in the middle stage of aging; A>15, the rubber powder modified asphalt is in the late stage of aging.

2. The method for evaluating the aging degree of rubber-crushed modified asphalt according to claim 1, characterized in that: The calculation formula of aging degree A is: A=functional group index growth ratio of asphalt partition × proportion of asphalt partition + functional group index growth ratio of rubber powder partition × proportion of rubber powder partition + functional group index growth ratio of asphalt and rubber powder interactive partition × proportion of asphalt and rubber powder interactive partition.

3. The method for evaluating the aging degree of rubber-crushed modified asphalt according to claim 1, characterized in that: The calculation formula for the proportion of the three partitions is: ； ； 。 4. The method for evaluating the aging degree of rubber-crushed modified asphalt according to claim 1, characterized in that: Asphalt partitions are homogeneous phase regions in microscopic morphology; The rubber powder is divided into the granular phase area in the microscopic morphology; The interaction between asphalt and rubber powder is divided into the interaction area of ​​uniform phase and granular phase in the microscopic morphology.

5. The method for evaluating the aging degree of rubber-modified asphalt according to claim 1, characterized in that the asphalt The characteristic peak of the partition is the sulfoxide group peak; The characteristic peak of rubber powder partition is trans-olefin peak; The characteristic peak of the interactive partition between asphalt and rubber powder is the white carbon black peak.

6. The method for evaluating the aging degree of rubber-crushed modified asphalt according to claim 5, characterized in that the asphalt The functional group index of the partition characteristic peak is the ratio of the sulfoxide peak area to the reference peak area; The functional group index of the characteristic peak of rubber powder partition is the ratio of the trans-olefin peak area to the reference peak area; The functional group index of the characteristic peak of the interactive partition between asphalt and rubber powder is the ratio of the peak area of ​​white carbon black to the peak area of ​​the reference peak; The reference peak is 1376 cm -1 The methyl umbrella vibration peak at .

7. The method for evaluating the aging degree of rubber-crushed modified asphalt according to claim 1, characterized in that: The formula for calculating the functional group exponential growth ratio is: 。 8. The method for evaluating the aging degree of rubber-crushed modified asphalt according to claim 1, characterized in that: The film samples before aging were prepared by solution method or cryosectioning method; The preparation method of the solution process comprises the following steps: The rubber powder modified asphalt before aging is dissolved in trichloroethylene solution and shaken thoroughly to obtain a mixed solution, and then the mixed solution is added to a potassium bromide sheet, and a film sample is obtained after the trichloroethylene is volatilized; The preparation method of the frozen section method comprises the following steps: The rubber powder modified asphalt before aging is immersed in embedding liquid, and the embedding liquid is cooled into a solid and then cut to obtain the film sample before aging; The preparation method of the film samples after aging is the same as that of the film samples before aging.

9. An evaluation system for the aging degree of rubber-crushed modified asphalt, characterized in that: The evaluation system is used to execute the steps in the method for evaluating the aging degree of rubber-crushed modified asphalt according to any one of claims 1 to 8, and the evaluation system includes a data acquisition module, a data processing module, a data calculation module and an evaluation module; The data acquisition module is used for infrared scanning to obtain an infrared spectrum; The data processing module is used to calculate the characteristic peak functional group index according to the infrared spectrum; The data calculation module is used to combine the functional group index of the characteristic peak to obtain the functional group index growth ratio of the three partitions, and the functional group index growth ratio of the three partitions is multiplied by the proportion of each of the three partitions and then summed to obtain a comprehensive index; The evaluation module is used to evaluate the multiphase aging degree of the rubber powder modified asphalt by using the comprehensive index as an aging degree evaluation index.

10. A storage medium, characterized in that: The storage medium stores a computer program, which is executed by a processor to implement the steps of a method for evaluating the aging degree of rubber-crushed modified asphalt as described in any one of claims 1 to 8.

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