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

Abstract

The present invention discloses an evaluation method, system and storage medium for the aging degree of rubber powder modified asphalt, and belongs to the field of road engineering technology. The evaluation method of the present invention is: the rubber powder modified asphalt before and after aging is prepared into thin film samples respectively, the microscopic morphology is observed, and the samples are divided into three partitions before and after aging according to the microscopic morphology results, the three partitions before and after aging are subjected to infrared scanning, and infrared spectra of the three partitions before and after aging are obtained, and the functional group index of the characteristic peaks of the three partitions before and after aging is calculated based on the characteristic peaks of the three partitions before and after aging; thereby, the functional group index growth ratio of the three partitions is calculated; and the aging degree of the rubber powder modified asphalt is evaluated based on the functional group index growth ratio of the three partitions and the proportion of the three partitions. The present invention determines the aging degree of each phase in the aging process and its contribution to the overall aging from the perspective of multiphase states, and accurately evaluates the complex aging behavior of the rubber powder modified asphalt.

Description

Technical Field

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

[0002] Aging of crumb rubber-modified asphalt reduces the tensile strength of asphalt pavements, making them more susceptible to cracking. The presence of cracks significantly increases the risk of rainwater infiltration into the pavement structure, which can damage the pavement structure. Furthermore, asphalt adhesion gradually diminishes with aging, causing the asphalt film to peel from the aggregate surface, ultimately leading to pavement defects such as loosening and potholes. Therefore, accurately characterizing the aging behavior of asphalt materials and understanding their aging mechanisms are fundamental to improving their aging resistance or delaying aging, and are crucial for the development of long-life pavements.

[0003] Among existing characterization methods, Fourier transform infrared spectroscopy is used to characterize the chemical structure changes of crumb rubber-modified asphalt during aging. By comparing the infrared spectra of asphalt samples before and after aging, changes in functional groups in the samples can be detected, thereby assessing the impact 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 the micromorphology of crumb rubber-modified asphalt during aging. By comparing the micrographs before and after aging, changes in the crumb rubber particles in the samples can be observed, thereby assessing the impact of aging on the micromorphology of crumb rubber-modified asphalt. However, the complex composition of crumb rubber-modified asphalt leads to asphalt oxidation, crumb rubber swelling and degradation, and material interactions between the asphalt and crumb rubber during aging. Fourier transform infrared spectroscopy can only obtain the infrared spectrum of the entire sample and cannot distinguish molecular structural changes between different phases. Microscopic methods can also only observe changes in the sample's micromorphology, but cannot understand the molecular structural changes caused by changes in the morphology of each phase at the microscopic level. Summary of the Invention

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

[0006] The rubber powder modified asphalt before aging was prepared into a pre-aging film sample, and the micromorphology of the pre-aging film sample was observed. According to the micromorphology results, it was divided into three zones before aging, namely the asphalt zone before aging, the rubber powder zone before aging, and the asphalt and rubber powder interactive zone before aging.

[0007] The three partitions before aging are subjected to infrared scanning to obtain infrared spectra of the three partitions before aging, and characteristic peak functional group indices of the three partitions before aging are calculated based on characteristic peaks of the three partitions before aging in the infrared spectra.

[0008] The testing method of the rubber powder modified asphalt after aging is the same as the operating method of the rubber powder modified asphalt before aging, and the characteristic peak functional group index of the three partitions after aging is obtained; the testing method of the rubber powder modified asphalt after aging is: the aged rubber powder modified asphalt is prepared into aged film samples, and the microscopic morphology of the film samples is observed using the microscope system of an infrared microscope. According to the microscopic morphology results, the samples are divided into three partitions after aging, namely, the aged asphalt partition, the aged rubber powder partition, and the aged asphalt and rubber powder interactive partition.

[0009] The three partitions after aging are subjected to infrared scanning to obtain infrared spectra of the three partitions after aging, and the characteristic peak functional group indices of the three partitions after aging are calculated based on the characteristic peaks of the three partitions after aging in the infrared spectra.

[0010] The functional group index growth ratios of the three partitions were calculated based on the functional group indexes of the characteristic peaks of the three partitions before aging and the functional group indexes of the characteristic peaks of the three partitions after aging.

[0011] 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 proportion of the three partitions.

[0012] 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.

[0013] The present invention is based on the multiphase state to evaluate the aging degree of rubber powder modified asphalt. The multiphase state refers to the changes in the asphalt, the changes in the rubber powder, and the material interaction between the two during the aging process of the rubber powder modified asphalt. The present invention combines an optical microscope and a Fourier transform infrared spectrometer to perform infrared scanning on a selected area of ​​the rubber powder modified asphalt, obtain an infrared spectrum of the selected area, and then study the selected area. The selected area is usually tens of microns to several millimeters. It should be noted that the present invention can choose to use an instrument that has both micromorphology testing and infrared testing functions for testing, or use an instrument equipped with micromorphology testing for testing, and then use an instrument equipped with infrared testing for testing. If two instruments are selected for testing separately, the test points of the sample must correspond precisely.

[0014] The aged rubber-modified asphalt of the present invention can be prepared by artificial aging or extracted from a naturally aged sample. When artificial aging is used, for example, a simulation test is performed in a heat, light and water coupled aging chamber.

[0015] In a preferred embodiment of the present invention, the calculation formula of the aging degree A is:

[0016] A=Asphalt partition functional group index growth ratio × asphalt partition proportion + rubber powder partition functional group index growth ratio × rubber powder partition proportion + asphalt and rubber powder interactive partition functional group index growth ratio × asphalt and rubber powder interactive partition proportion.

[0017] In a preferred embodiment of the present invention, the calculation formula for the proportion of the three partitions is:

[0018] .

[0019] .

[0020] .

[0021] In a preferred embodiment of the present invention, the asphalt partition is a uniform phase region in microscopic morphology.

[0022] The rubber powder partition is a granular phase region in the microscopic morphology.

[0023] The asphalt and rubber powder interactive partition is a uniform phase and a granular phase interactive area in the microscopic morphology.

[0024] In a preferred embodiment of the present invention, the characteristic peak of the asphalt partition is a sulfoxide peak.

[0025] The characteristic peak of rubber powder partition is trans-olefin peak.

[0026] The characteristic peak of the interaction partition between asphalt and rubber powder is the silica peak.

[0027] In a preferred embodiment of the present invention, the functional group index of the characteristic peak of the asphalt partition is the ratio of the sulfoxide peak area to the reference peak area; the calculation formula of the functional group index of the characteristic peak of the asphalt partition is:

[0028] ;

[0029] in, I SU is the sulfoxide index, A 1031 is the sulfoxide peak area, A 1376 is the reference peak area.

[0030] The functional group index of the characteristic peak of the rubber powder partition is the ratio of the trans-olefin peak area to the reference peak area.

[0031] The calculation formula of the functional group index of the characteristic peak of rubber powder partition is:

[0032] ;

[0033] in, I PB is the butadiene index, A 965 is the trans-olefin peak area, A 1376 is the reference peak area.

[0034] 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 ​​silica to the peak area of ​​the reference peak.

[0035] The calculation formula for the functional group index of the characteristic peak of the interaction partition between asphalt and rubber crumb is:

[0036] ;

[0037] in, I Si-O-Si is the silicon-oxygen index, A 1100 is the peak area of ​​silica, A 1376 is the reference peak area.

[0038] The reference peak is 1376 cm -1 The methyl umbrella vibration peak at .

[0039] In a preferred embodiment of the present invention, the formula for calculating the functional group exponential growth ratio is:

[0040] .

[0041] In a preferred embodiment of the present invention, the film sample before aging is prepared by a solution method or a frozen section method.

[0042] The preparation method of the solution method comprises the following steps:

[0043] The rubber powder modified asphalt before aging is dissolved in trichloroethylene solution and shaken thoroughly to obtain a mixed solution, which is then added to a potassium bromide sheet. After the trichloroethylene is volatilized, a film sample is obtained.

[0044] The preparation method of the frozen section method includes the following steps:

[0045] The pre-aged rubber powder-modified asphalt was immersed in embedding solution. After the embedding solution cooled to a solid state, the pre-aged film sample was cut. Specifically, 0.1g of the rubber powder-modified asphalt was immersed in embedding solution and then placed in an environment of -12°C. After the embedding solution cooled to a solid state, it was placed on a cryostat, and the slice thickness parameter was set to 30μm to 50μm. The film sample was then cut.

[0046] The preparation method of the film samples after aging is the same as that of the film samples before aging.

[0047] The second object of the present invention is to provide an evaluation system for the aging degree of the above-mentioned rubber-crushed modified asphalt, which is used to execute the steps in the above-mentioned method for evaluating the aging degree of the rubber-crushed modified asphalt. The evaluation system includes a data acquisition module, a data processing module, a data calculation module and an evaluation module.

[0048] The data acquisition module is used for infrared scanning to obtain an infrared spectrum.

[0049] The data processing module is used to calculate the characteristic peak functional group index based on the infrared spectrum.

[0050] The data calculation module is used to combine the characteristic peak functional group index 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.

[0051] The evaluation module is used to evaluate the multiphase aging degree of the crumb rubber modified asphalt using the comprehensive index as an aging degree evaluation index.

[0052] A third object of the present invention is to provide a storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the steps of the above-mentioned method for evaluating the aging degree of rubber-modified asphalt.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] The present invention provides a method for evaluating the aging degree of rubber-crushed modified asphalt. The infrared microscope system can simultaneously characterize the changes in the micromorphology and chemical structure during the aging process of the rubber-crushed modified asphalt, realize non-physical phase separation, and analyze the changes in each phase during the aging process of the rubber-crushed modified asphalt from a multiphase perspective. The aging behavior of the rubber-crushed modified asphalt can be evaluated more accurately and objectively.

[0055] The method of the present invention avoids physical phase separation of rubber-powder modified asphalt, reduces the difficulty of the experiment, overcomes the disadvantage that existing characterization methods cannot perform multi-phase synchronous characterization, and analyzes the changes in asphalt and rubber powder during the aging process of rubber-powder modified asphalt, as well as the influence of the material interaction between the two on its aging behavior. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 Schematic diagram of the calculation of peak areas of different functional groups in the present invention.

[0057] Figure 2 The figures are the micrographs and infrared spectra of the asphalt partitions of the rubber powder modified asphalt of the present invention after aging for 2 days, wherein (a) is the micrograph, and (b) is the infrared spectra obtained from the scanning point of the asphalt partition at position A in (a).

[0058] Figure 3 The figures are the micrograph and infrared spectrum of the rubber powder partition of the rubber powder modified asphalt of the present invention after aging for 2 days, wherein (a) is the micrograph, and (b) is the infrared spectrum obtained from the scanning point of the rubber powder partition at position A in (a).

[0059] Figure 4 The figures are a micrograph and an infrared spectrum of the interactive partition between asphalt and rubber powder of the rubber powder modified asphalt of the present invention after aging for 2 days, wherein (a) is a micrograph, and (b) is an infrared spectrum obtained from the scanning point of the interactive partition between asphalt and rubber powder at position A in (a).

[0060] Figure 5 Schematic diagram of the asphalt partition sulfoxide index in the rubber-modified asphalt samples with different aging times in Example 1 of the present invention.

[0061] Figure 6 Schematic diagram of the butadiene index of the rubber powder partitions in the rubber powder modified asphalt samples with different aging times in Example 1 of the present invention.

[0062] Figure 7 Schematic diagram of the interactive partitioning silicon-oxygen index in the rubber-modified asphalt samples with different aging times in Example 1 of the present invention.

[0063] Figure 8 Schematic diagrams of the changing trends of the functional group indices and the complex modulus of the rubber crumb modified asphalt samples at different aging times in Example 1 of the present invention, wherein (a) is a schematic diagram of the changing trends of the functional group indices, and (b) is a schematic diagram of the changing trends of the complex modulus. DETAILED DESCRIPTION

[0064] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0065] The rubber powder used in the present invention is 40-mesh ordinary radial waste tire rubber powder purchased from Chongqing Jiuxianghua Rubber Technology Co., Ltd., and the SBS modifier used is YH-791H linear SBS modifier purchased from Baling Petrochemical Co., Ltd.

[0066] Example 1

[0067] This embodiment discloses a method for evaluating the aging degree of rubber-modified asphalt. Figure 1 As shown, the specific steps include:

[0068] S1. The preparation method of rubber powder modified asphalt is as follows:

[0069] First, 15 parts of rubber powder were mixed with 85 parts of Jingbo 70# base asphalt and stirred at 200℃ for 6 hours; then the preparation temperature was adjusted to 180℃ and 2 parts of SBS modifier were added and stirred for another 1.5 hours; finally, 0.2 parts of sulfur were added while maintaining the preparation temperature at 180℃ and stirred for another hour to obtain rubber powder modified asphalt.

[0070] The rubber powder modified asphalt was subjected to a heat, light and water coupled aging indoor simulation test. The operating steps were as follows: the rubber powder modified asphalt was heated at 163°C for 0.5h to make the asphalt flowable; then 20g of a sample with a film thickness of 1000μm was accurately weighed and poured into a standard aging tray with a diameter of 14cm. The rubber powder modified asphalt in the standard aging tray was evenly spread and placed in a coupled aging box; the test temperature of the coupled aging box was adjusted to 60°C and the humidity to 66%, and the high-pressure mercury lamp was turned on to start the coupled aging test; in order to ensure uniform lighting, the position of the aging tray was adjusted every 24h.

[0071] 0.2 g of samples aged for 0 days, 2 days, 4 days, 8 days, and 16 days were taken respectively, dissolved in 3 mL of trichloroethylene and shaken thoroughly, and then the mixed solution was dropped on a potassium bromide sheet to obtain different film samples.

[0072] It should be noted that the film sample obtained after aging for 0 days is the film sample before aging, recorded as FH-0d, and the film samples obtained after aging for 2 to 16 days are the film samples after aging to different degrees, recorded as FH-2d, FH-4d, FH-8d, and FH-16d, respectively.

[0073] S2. Observe the micromorphology of the pre-aging film sample using an infrared microscope. Based on the micromorphological results, the sample is divided into three pre-aging zones: the pre-aging asphalt zone, the pre-aging rubber powder zone, and the pre-aging asphalt and rubber powder interaction zone. Infrared scanning is performed on the three pre-aging zones to obtain infrared spectra of the three pre-aging zones. Based on the characteristic peaks in the infrared spectra, the functional group indices of the characteristic peaks of the three pre-aging zones are calculated.

[0074] 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.

[0075] Specifically, the micromorphology of the aged film samples was observed using an infrared microscope. Based on the micromorphological results, the samples were divided into three zones: the aged asphalt zone, the aged rubber powder zone, and the aged asphalt and rubber powder interaction zone. Infrared scanning was performed on the three zones to obtain infrared spectra. Based on the characteristic peaks in the infrared spectra, the functional group indices of the characteristic peaks of the three zones were calculated.

[0076] Specifically, different film samples were placed on the instrument's stage and the instrument was adjusted to transmit light through the film samples. Parameters were then set on a computer, and different partitions were identified under the microscope image. The different partitions identified under the microscope image were: the homogeneous phase was selected as the asphalt partition; the granular phase was selected as the rubber powder partition; and the region where the homogeneous and granular phases interacted was selected as the asphalt-rubber powder interaction partition. Finally, the identified partitions were scanned to obtain their corresponding infrared spectra.

[0077] The calculation formula of the functional group index that can represent the change of asphalt partition is:

[0078] ;

[0079] in, I SU is the sulfoxide index, A 1031 is the sulfoxide peak area, A 1376 is the reference peak area.

[0080] The calculation formula of the functional group index that can represent the change of rubber powder partition is:

[0081] ;

[0082] in, I PB is the butadiene index, A 965 is the trans-olefin peak area, A 1376 is the reference peak area.

[0083] The calculation formula of the functional group index that can represent the change of interactive partition is:

[0084] ;

[0085] in, I Si-O-Si is the silicon-oxygen index,A 1100 is the peak area of ​​silica, A 1376 is the reference peak area.

[0086] It should be noted that when conducting aging research, 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 reflects only the effect of aging. The reference peak is generally selected from the peak that is less affected by aging. In this invention, 1376 cm -1 The methyl umbrella vibration at 37° was used as the reference peak.

[0087] It should be noted that the integration range of functional groups in asphalt samples is the same, and the peak areas of different functional groups are calculated as follows: Figure 1 As shown, the peak area integration function of the Origin software was used for calculation. The integration ranges of different functional groups are as follows:

[0088] 965cm -1 The integration range of the butadiene group at 929.7 cm -1 ~979.8cm -1 .

[0089] 1031cm -1 The integration range of the sulfoxide group is 981.7 cm -1 ~1045.3cm -1 .

[0090] 1100cm -1 The integration range of the siloxy group at 1045.3 cm -1 ~1139.9cm -1 .

[0091] 1376cm -1 The integration range of the CH3 symmetric angle group is 1325.1 cm -1 ~1392.6cm -1 .

[0092] S3. Calculate the functional group index growth ratios of the three partitions based on the characteristic peak functional group indices of the three partitions before aging and the characteristic peak functional group indices of the three partitions after aging.

[0093] .

[0094] S4. Evaluate the aging degree of the rubber crumb modified asphalt based on the functional group index growth ratio of the three partitions and the proportion of the three partitions.

[0095] .

[0096] .

[0097] .

[0098] The calculation formula of aging degree A is as follows:

[0099] A=Asphalt partition functional group index growth ratio × asphalt partition proportion + rubber powder partition functional group index growth ratio × rubber powder partition proportion + asphalt and rubber powder interactive partition functional group index growth ratio × asphalt and rubber powder interactive partition proportion.

[0100] In this embodiment, the evaluation of the multiphase aging degree of rubber powder modified asphalt after light, heat and water coupled aging for different periods of time is taken as an example to illustrate the implementation effect of the present invention. A total of five rubber powder modified asphalt samples with aging times of 0 days, 2 days, 4 days, 8 days and 16 days are selected, which are defined as FH-0d, FH-2d, FH-4d, FH-8d and FH-16d respectively. The rate of change of the macroscopic properties of the asphalt sample decreases with the increase of aging time, so the rate of change of its various phases should also decrease with the increase of aging time. Based on the method proposed in the present invention, the multiphase aging behavior of rubber powder modified asphalt can be characterized and compared with the trend of macroscopic performance changes, which can further verify the reliability of the method of the present invention.

[0101] The micrographs and infrared spectra of each phase of the rubber powder modified asphalt after aging for 2 days are as follows: Figures 2 to 4 shown. Figure 2 (b) in the equation is Figure 2 (a) Infrared spectrum obtained at the scanning point of the asphalt partition at A. Figure 3 (b) in the equation is Figure 3 (a) Infrared spectrum obtained at the scanning point of the asphalt partition at A. Figure 4 (b) in the equation is Figure 4 (a) shows the infrared spectrum obtained at the scanning point of the asphalt partition at A. Origin software was then used to calculate the representative peak areas of the infrared spectra of different partitions, and to obtain the functional group index that can represent the changes in different partitions. A schematic diagram of the asphalt micro-region sulfoxide index of the rubber crumb modified asphalt samples with different aging times is shown in Figure 2. Figure 5 As shown in the figure, the increase of sulfoxide index from 0d to 2d is not obvious, indicating that although asphalt oxidation occurs at this stage, it is not severe; the increase of sulfoxide index from 2d to 4d is most obvious, indicating that the asphalt oxidation reaction is severe at this stage; and the increase of sulfoxide index from 4d to 8d becomes smaller, indicating that the oxidation reaction begins to weaken; and finally from 8d to 16d, the aging time increases significantly, while the sulfoxide index remains almost unchanged, indicating that the asphalt phase hardly undergoes oxidation reaction in the later stage of aging.

[0102] Schematic diagram of butadiene index of rubber powder micro-area of ​​rubber powder modified asphalt samples with different aging times Figure 6 As shown in the figure, through semi-quantitative comparison, it can be found that the butadiene index of the rubber powder increases significantly in the early stage of aging from 0d to 2d, indicating that the rubber powder has been degraded in the early stage of aging of the rubber powder modified asphalt; and during the period from 2d to 4d, the butadiene index of the rubber powder micro-area increases significantly, indicating that the rubber powder is severely degraded in this stage; as the aging time continues to increase, the butadiene index of the rubber powder micro-area increases very slowly from 4d to 8d and from 8d to 16d, indicating that the degradation of the rubber powder has been basically completed in the later stage of aging, and further increasing the aging time has little effect on the degradation of the rubber powder.

[0103] Schematic diagram of the silica index of the interactive micro-regions of rubber-modified asphalt samples with different aging times. Figure 7 As shown in the graph, the change in the silica index indicates that the silica index of the rubber-modified asphalt is essentially zero before aging. Before surface aging, no interaction occurs between the rubber and asphalt phases. However, this interaction gradually occurs from 0 to 8 days. The silica index increases linearly with aging time, and by the end of the aging period, virtually no interaction occurs. This indicates that the interaction between the asphalt and the rubber continues from 0 to 8 days, and ceases at the end of the aging period as the changes in the asphalt and rubber cease.

[0104] Table 1 summarizes the aging performance indicators of crumb rubber-modified asphalt tested using conventional methods at different aging times. It can be seen that the changing patterns of the various performance aging indices for crumb rubber-modified asphalt mirror those of the functional group indices for each partition: both show dramatic changes between 0 and 4 days, but remain essentially unchanged in the later stages of aging. This further demonstrates the reliability and rationality of the proposed method.

[0105] Table 1 Aging performance index results

[0106]

[0107] To further evaluate the aging of the various phases and overall degree of aging of the crumb rubber-modified asphalt, Table 2 calculates the growth ratios of the functional group indices of each partition of the crumb rubber-modified asphalt before and after aging, as well as the proportions of each partition. It can be seen that the interaction partition experiences the greatest change after aging, indicating that the interaction phase has the highest degree of aging. Furthermore, the overall aging degree shows that the degree of aging of the crumb rubber-modified asphalt gradually increases in the early stages of aging, but remains essentially unchanged in the later stages. This is consistent with the changes in rheological properties, further demonstrating the reliability and rationality of the aging degree evaluation method proposed in this paper.

[0108] It should be noted that in rubber powder modified asphalt, the main phases are asphalt phase and rubber powder phase, and the interactive phase is an interactive behavior between asphalt and rubber powder. Therefore, the interactive phase is regarded as asphalt and rubber powder here, so the whole is twice as much asphalt and rubber powder.

[0109] Table 2 Aging results of different samples

[0110]

[0111] Table 2 shows the aging results of different samples. Combined with the changes in all aging properties, it can be considered that when 0≤A≤8, the rubber powder modified asphalt is in the early stage of aging, at which time all phases participate in the reaction, resulting in obvious changes in rheological properties; when 8<A≤15, the rubber powder modified asphalt is in the middle stage of aging, at which time the reactions of various phases are most intense, resulting in the largest changes in rheological properties in this stage; when A>15, the rubber powder modified asphalt is in the late stage of aging, at which time the reaction rates of various phases drop sharply and the changes in rheological properties also tend to be gentle.

[0112] The aging evaluation method proposed in this paper comprehensively considers the influence of each component phase during the aging process of crumb rubber-modified asphalt and accurately assesses the contribution of each phase to the aging process. This overcomes the shortcomings of existing evaluation methods that fail to account for multiple phases. It can accurately evaluate the complex aging behavior of crumb rubber-modified asphalt, providing targeted guidance for anti-aging and regeneration research on crumb rubber-modified asphalt.

[0113] In order to compare and illustrate the superiority of the method of the present invention, the present invention further calculated the trend of the change of the sulfoxide index, butadiene index and silicon oxygen index of the whole sample with the aging time according to the existing characterization method of "Rapid Analysis Method and Reliability Research of Asphalt Based on Infrared Spectroscopy" published by Chen Fei et al. in the 6th issue of Volume 38 of "Highway Traffic Technology" in December 2022, and compared it with the trend of the change of the complex modulus. The results are as follows Figure 8 As shown in the figure, the sulfoxide index and butadiene index of the samples obtained using existing characterization methods only changed between 0 and 2 days, remaining essentially unchanged thereafter. The silica index, on the other hand, increased between 0 and 2 days and between 4 and 8 days, remaining unchanged during the remaining aging periods. However, the changes in macroscopic properties during aging primarily occurred between 0 and 4 days, contradicting the results obtained using existing characterization methods. Therefore, existing characterization methods cannot accurately assess the aging degree of crumb rubber-modified asphalt.

[0114] It should be noted that the complex modulus is obtained by testing using a dynamic shear rheometer according to the AASHTO MP1a-04 method at a test temperature of 64°C.

[0115] In summary, the multiphase-based aging degree evaluation method for rubber powder modified asphalt proposed in the present invention can accurately evaluate the aging degree of each phase of rubber powder modified asphalt during the aging process and the overall aging degree of rubber powder modified asphalt, overcoming the shortcomings of existing evaluation methods that cannot consider the influence of multiphase states, and providing targeted positioning for the anti-aging and regeneration research of rubber powder modified asphalt.

[0116] Example 2

[0117] This embodiment provides an evaluation system for the aging degree of rubber-modified asphalt, comprising a data acquisition module, a data processing module, a data calculation module, and an evaluation module.

[0118] The data acquisition module is used for infrared scanning to obtain infrared spectra. Specifically, the infrared microscope's microscopic system is used to scan and obtain three pre-aging partitions and three post-aging partitions. The three pre-aging partitions are the pre-aging asphalt partition, the pre-aging rubber powder partition, and the pre-aging asphalt and rubber powder interaction partition. The three post-aging partitions are the post-aging asphalt partition, the post-aging rubber powder partition, and the post-aging asphalt and rubber powder interaction partition.

[0119] Infrared scanning is performed on the three partitions before aging and the three partitions after aging to obtain infrared spectra.

[0120] The data processing module is used to calculate the functional group index of the characteristic peak according to the infrared spectrum.

[0121] The data calculation module is used to combine the characteristic peak functional group index 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.

[0122] The evaluation module is used to evaluate the multiphase aging degree of the crumb rubber modified asphalt by using the comprehensive index as an aging degree evaluation index.

[0123] Example 3

[0124] 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 disk. The computer program is executed by a processor to implement the steps of a method for evaluating the degree of aging of crumb rubber-modified asphalt.

[0125] As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0126] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0127] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such 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, the film sample was divided into three pre-aging zones, namely the asphalt zone before aging, the rubber powder zone before aging, and the asphalt and rubber powder interaction zone before aging; Performing infrared scanning on the three partitions before aging to obtain infrared spectra of the three partitions before aging, and calculating characteristic peak functional group indices of the three partitions before aging based on characteristic peaks 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 ratios of the three partitions are calculated based on the functional group indexes of the characteristic peaks of the three partitions before aging and the functional group indexes 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 proportion of the three partitions; The calculation formula for the aging degree A is: A = growth ratio of functional group index of asphalt partition × proportion of asphalt partition + growth ratio of functional group index of rubber powder partition × proportion of rubber powder partition + growth ratio of functional group index of interactive partition of asphalt and rubber powder × proportion of interactive partition of asphalt and rubber powder; 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-modified asphalt according to claim 1, characterized in that: The calculation formula for the proportion of the three partitions is: ； ； 。 3. The method for evaluating the aging degree of rubber-modified asphalt according to claim 1, wherein: Asphalt partitions are homogeneous phase regions in the microscopic morphology; The rubber powder partition is 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 micromorphology.

4. The method for evaluating the aging degree of rubber-modified asphalt according to claim 1, wherein 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 interaction partition between asphalt and rubber powder is the silica peak.

5. The method for evaluating the aging degree of rubber-modified asphalt according to claim 4, wherein 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 ​​silica to the peak area of ​​the reference peak; The reference peak is 1376 cm -1 The methyl umbrella vibration peak at .

6. The method for evaluating the aging degree of rubber-modified asphalt according to claim 1, wherein: The formula for calculating the functional group exponential growth ratio is: 。 7. The method for evaluating the aging degree of rubber-modified asphalt according to claim 1, characterized in that: The film samples before aging were prepared by solution method or frozen section method; The preparation method of the solution method 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 tablet, and a film sample is obtained after the trichloroethylene is volatilized; The preparation method of the frozen section method includes 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.

8. An evaluation system for the aging degree of rubber-modified asphalt, characterized in that: The evaluation system is used to execute the steps of the method for evaluating the aging degree of rubber-modified asphalt according to any one of claims 1 to 7, 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 based on 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 crumb rubber modified asphalt using the comprehensive index as an aging degree evaluation index.

9. A storage medium, characterized in that: The storage medium stores a computer program, which is executed by a processor to implement the steps of the method for evaluating the aging degree of crumb rubber modified asphalt according to any one of claims 1 to 7.

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