Method for evaluating desulfurization degree of bio-desulfurized rubber powder for modified asphalt

Abstract

The present application relates to the technical field of road engineering, in particular to a desulfurization degree evaluation method of bio-desulfurized rubber powder for modified asphalt, which comprises Fourier infrared spectrum attenuated total reflection testing and EA element analysis testing on waste tire rubber powder and bio-desulfurized rubber powder, baseline calibration and smoothing processing on the transmittance spectrum, calculation of S-S bond and C-S bond correction peak area reduction rate, and calculation of S element content reduction rate, so as to calculate the desulfurization degree index DI value, which can quickly evaluate the desulfurization degree of bio-desulfurized rubber powder. The evaluation method and evaluation index proposed by the present application have the characteristics of short time consumption, convenient operation and high precision, can realize quick and accurate evaluation of the desulfurization degree of bio-desulfurized rubber powder in the screening stage of preparing desulfurized rubber powder modified asphalt materials, and can appropriately predict the physical properties of modified asphalt prepared by desulfurized rubber powder.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road engineering, in particular to a desulfurization degree evaluation method of bio-desulfurized rubber powder for modified asphalt. BACKGROUND

[0002] Due to excellent high-temperature elastic properties and green environmental benefits, the use of waste tire rubber powder to prepare modified asphalt is widely used in the field of road engineering technology. Although waste tire rubber powder can significantly improve the high and low temperature rheological properties of modified asphalt and prolong the service life of pavement, its poor compatibility with asphalt and insufficient storage stability limit its development. Therefore, the bio-desulfurization technology of waste tire rubber powder is used to biologically enzymatically decompose the cross-linking and desulfurization of the original waste tire rubber powder. Through the targeted decomposition of S-S bonds and C-S bonds between the main chains of rubber by biological enzymes such as glutathione containing multiple sulfhydryl groups (-SH), the sulfur element in the rubber is consumed, thereby releasing part of the rubber chain, reducing the cross-linking network density of the rubber, increasing the sol content, and ultimately enhancing the compatibility of the desulfurized rubber with asphalt, significantly improving the storage stability of rubber modified asphalt. However, when using rubber powder as an asphalt modifier, the desulfurization degree needs to be controlled. Too low desulfurization degree represents too low cross-linking degree of rubber powder, and the cross-linking network of rubber chain has not been cross-linked to a sufficient degree, and its compatibility with asphalt remains at a poor level, which has no obvious improvement effect on the storage stability of rubber powder modified asphalt. Too high desulfurization degree represents too high cross-linking degree of rubber powder, and the cross-linking network structure of the rubber chain is too large in cross-linking degree and diffusion degree, the average molecular weight of the rubber chain is reduced, and the free volume is significantly increased, resulting in a significant decrease in the elastic properties, which adversely affects the high-temperature elastic properties of desulfurized rubber powder modified asphalt. Therefore, it is indispensable to evaluate the desulfurization degree of bio-desulfurized rubber powder before preparing desulfurized rubber powder modified asphalt.

[0003] The method for measuring the activation degree of desulfurized rubber powder specified in GB / T3516-2006 standard is time-consuming and inefficient, and cannot be linked to the performance of the corresponding modified asphalt. Currently, some new methods for detecting the desulfurization degree of desulfurized rubber powder have been proposed. For example, patent CN 115683772 A discloses a method for detecting the activation degree of desulfurized rubber powder, which prepares a ductility test piece by mixing the sample to be tested with base asphalt, then performs a force-ductility test, calculates the integral area ratio of the force-ductility curve of the sample to be tested, and substitutes it into the standard curve to calculate the activation degree of the desulfurized rubber powder. However, this method requires the preparation of modified asphalt using the desulfurized rubber powder to be tested before testing to obtain the results, and the operation steps are relatively complex. Patent CN 118165361 A calculates the increase rate of the swelling rate of rubber in toluene solution before and after desulfurization as an index of desulfurization by means of immersion test, but this method is time-consuming and toluene solvent is toxic. Therefore, a desulfurization degree evaluation method of bio-desulfurized rubber powder for modified asphalt is proposed. SUMMARY

[0004] In view of the defects of the prior art, the present application provides a desulfurization degree evaluation method for bio-desulfurized rubber powder for modified asphalt, which obtains the S-S bond, C-S bond corrected peak area reduction rate and S element content reduction rate through Fourier infrared spectroscopy attenuated total reflection testing and EA element analysis testing on waste tire rubber powder and bio-desulfurized rubber powder, and calculates a modified asphalt rubber powder desulfurization degree index DI value, so as to quickly and conveniently evaluate the desulfurization degree of bio-desulfurized rubber powder, and has the characteristics of short time consumption and simple operation.

[0005] To achieve the above object, the present application provides the following technical scheme: a desulfurization degree evaluation method for bio-desulfurized rubber powder for modified asphalt, comprising the following steps,

[0006] (1) respectively performing tablet processing and EA element analysis testing pretreatment on waste tire rubber powder to obtain Fourier infrared spectroscopy attenuated total reflection tablet test pieces and EA element analysis test pieces;

[0007] (2) performing attenuated total reflection testing on the Fourier infrared spectroscopy attenuated total reflection tablet test pieces to obtain a transmittance infrared spectrum curve of the waste tire rubber powder;

[0008] identifying the S-S bond and C-S bond characteristic peaks in the transmittance infrared spectrum curve, and calculating the S-S bond and C-S bond corrected peak areas of the waste tire rubber powder, which are respectively denoted as

[0009] (3) performing EA element analysis testing on the EA element analysis test pieces to obtain the S element content of the waste tire rubber powder, denoted as S0;

[0010] (4) performing desulfurization treatment on the waste tire rubber powder to obtain bio-desulfurized rubber powder; performing the same treatment on the bio-desulfurized rubber powder in the manner of steps (1)-(3) to obtain the S-S bond, C-S bond corrected peak areas and S element content of the bio-desulfurized rubber powder, which are respectively denoted as and S1;

[0011] (5) taking the waste tire rubber powder as a reference, calculating the reduction rates of the S-S bond, C-S bond corrected peak areas and S element content of the bio-desulfurized rubber powder, which are respectively denoted as and R ΔS ;

[0012] (6) substituting the S-S bond and C-S bond corrected peak area reduction rates and the S element content reduction rate R ΔS into the DI value calculation formula to obtain the desulfurization degree index DI value of the bio-desulfurized rubber powder, and evaluating the desulfurization degree of the bio-desulfurized rubber powder according to the DI value,

[0013]

[0014] I grade desulfurization degree grade: DI < 30;

[0015] II grade desulfurization degree grade: 30≤DI≤60;

[0016] III grade desulfurization degree grade: DI>60.

[0017] Preferably, in step (2), the Fourier infrared spectrum attenuated total reflection wave number range is 400-4000cm -1 , and the scanning number is 32 times.

[0018] Preferably, in step (2), in the waste tire rubber powder, the correction peak area corresponding to S-S bond at infrared spectrum wave number 509cm -1 , and the correction peak area corresponding to C-S bond at infrared spectrum wave number 775cm -1 .

[0019] Preferably, in step (3), the analysis time of EA elemental analysis test is less than 5min.

[0020] Preferably, in step (4), in the biological desulfurization rubber powder, the correction peak area corresponding to S-S bond at infrared spectrum wave number 509cm -1 , and the correction peak area corresponding to C-S bond at infrared spectrum wave number 775cm -1 .

[0021] Preferably, in step (4), the desulfurization treatment is specifically: the Gordan's desulfurization bacteria is inoculated in 50mL culture medium containing waste tire rubber powder for free culture, and finally the biological desulfurization rubber powder is obtained.

[0022] Preferably, the culture temperature is selected as 20-30℃, the culture time is selected as 7-14 days, and the inoculation amount of Gordan's desulfurization bacteria is selected as 2-4%v / v.

[0023] Preferably, in step (5), and the calculation formula of R ΔS is as follows:

[0024] The present application provides a kind of desulfurization degree evaluation method of biological desulfurization rubber powder for modified asphalt, compared with prior art has the following beneficial effects:

[0025] 1. The application calculates the desulfurization degree index DI value of the waste tire rubber powder and the biological desulfurization rubber powder by the change of the corrected peak area of the internal S-S bond and C-S bond characteristic peak of the rubber powder and the change of the S element content, and the comprehensive reduction of the sulfur element in the rubber powder is used to represent the desulfurization degree of the desulfurized rubber powder, which can quantitatively detect and accurately judge the desulfurization degree of the biological desulfurization rubber powder, and further predict the performance of the biological desulfurization rubber powder modified asphalt.

[0026] 2. The application can directly test the Fourier infrared spectrum attenuated total reflection and EA element analysis of the rubber powder sample, obtain the S-S bond, C-S bond corrected peak area reduction rate and S element content reduction rate, and calculate the desulfurization degree index DI value, so as to quickly and conveniently evaluate the desulfurization degree of the biological desulfurization rubber powder for modified asphalt, and has the characteristics of convenient test operation, short test time and high result precision. BRIEF DESCRIPTION OF DRAWINGS

[0027] The drawings described herein are used to provide further understanding of the present application, and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application, and do not constitute an improper limitation on the present application. In the drawings:

[0028] Figure 1 It is a Fourier infrared spectrum characteristic peak correction peak area calculation schematic diagram in the application;

[0029] Figure 2 It is an infrared spectrum diagram of the rubber powder in examples 1-3 and example 5 in the application;

[0030] Figure 3 It is a S element content change diagram of the rubber powder in each example and each proportion in the application;

[0031] Figure 4 It is a performance corresponding curve diagram of the rubber powder modified asphalt with different DI values in the application. DETAILED DESCRIPTION

[0032] The following examples are used to illustrate the embodiments of the present application, so that the realization process of how to apply technical means to solve technical problems and achieve technical effects can be fully understood and implemented.

[0033] A desulfurization degree evaluation method of a biological desulfurization rubber powder for modified asphalt, comprising the following steps:

[0034] (1) The waste tire rubber powder is respectively subjected to tabletting treatment and EA element analysis test pretreatment to obtain Fourier infrared spectrum attenuated total reflection tabletting test pieces and EA element analysis test pieces.

[0035] (2) The Fourier infrared spectrum attenuated total reflection tabletting test pieces are subjected to attenuated total reflection test to obtain the transmittance infrared spectrum curve of the waste tire rubber powder;

[0036] The S-S bond and C-S bond characteristic peaks in the transmittance infrared spectrum curve are identified, and the S-S bond and C-S bond corrected peak areas of the waste tire rubber powder are calculated, which are respectively denoted as wherein is the corrected peak area corresponding to the S-S bond at the infrared spectrum wave number of 509 cm -1 . is the corrected peak area corresponding to the C-S bond at the infrared spectrum wave number of 775 cm -1 .

[0037] (3) The EA elemental analysis test is performed on the EA elemental analysis test sample to obtain the S element content of the waste tire rubber powder, which is denoted as S0.

[0038] (4) The waste tire rubber powder is subjected to desulfurization treatment to obtain a biological desulfurized rubber powder; the biological desulfurized rubber powder is subjected to the same treatment in the manner of steps (1)-(3) to obtain the S-S bond and C-S bond corrected peak areas and the S element content of the biological desulfurized rubber powder, which are respectively denoted as and S1; wherein is the corrected peak area corresponding to the S-S bond at the infrared spectrum wave number of 509 cm -1 . is the corrected peak area corresponding to the C-S bond at the infrared spectrum wave number of 775 cm -1 .

[0039] (5) The reduction rates of the S-S bond and C-S bond corrected peak areas and the S element content of the biological desulfurized rubber powder are calculated based on the waste tire rubber powder, which are respectively denoted as and R ΔS ; wherein

[0040] (6) The S-S bond and C-S bond corrected peak area reduction rates and the S element content reduction rate R ΔS of the biological desulfurized rubber powder are substituted into the DI value calculation formula to obtain the desulfurization degree index DI value of the biological desulfurized rubber powder, and the desulfurization degree of the biological desulfurized rubber powder is evaluated according to the DI value.

[0041]

[0042] I-grade desulfurization degree grade: DI < 30;

[0043] II-grade desulfurization degree grade: 30 ≤ DI ≤ 60;

[0044] III-grade desulfurization degree grade: DI > 60.

[0045] Example 1

[0046] S-S bond corrected peak area of the waste tire rubber powder was calculated by detection C-S bond corrected peak area and S element content value S0.

[0047] Example 2

[0048] S-S bond corrected peak area and C-S bond corrected peak area reduction rate of the biodesulfurized rubber powder A prepared from the waste tire rubber powder in Example 1 were calculated by detection and S element content reduction rate and the desulfurization degree index DI of the biodesulfurized rubber powder A was calculated A .

[0049] The biodesulfurized rubber powder A was obtained by inoculating Desulfuribacterium gordonii DSM 44462 into 50 mL of Luria-Bertani medium containing the waste tire rubber powder at an inoculation amount of 2% v / v and culturing it freely at 30°C for 14 days.

[0050] Example 3

[0051] S-S bond corrected peak area and C-S bond corrected peak area reduction rate of the biodesulfurized rubber powder B prepared from the waste tire rubber powder in Example 1 were calculated by detection and S element content reduction rate and the desulfurization degree index DI of the biodesulfurized rubber powder B was calculated B .

[0052] The biodesulfurized rubber powder B was obtained by inoculating Desulfuribacterium gordonii DSM 44462 into 50 mL of Luria-Bertani medium containing the waste tire rubber powder at an inoculation amount of 4% v / v and culturing it freely at 30°C for 14 days.

[0053] Example 4

[0054] S-S bond corrected peak area and C-S bond corrected peak area reduction rate of the biodesulfurized rubber powder C prepared from the waste tire rubber powder in Example 1 were calculated by detection and S element content reduction rate and the desulfurization degree index DI of the biodesulfurized rubber powder C was calculated C .

[0055] The biodesulfurized rubber powder C was obtained by inoculating Desulfuribacterium gordonii DSM 44462 into 50 mL of Luria-Bertani medium containing the waste tire rubber powder at an inoculation amount of 2% v / v and culturing it freely at 25°C for 14 days.

[0056] Example 5

[0057] The S-S bond, C-S bond corrected peak area reduction rate and S element content reduction rate of the biodesulfurized rubber powder D prepared from the waste tire rubber powder in Example 1 were calculated by detection and S element content reduction rate and the desulfurization degree index DI of the biodesulfurized rubber powder D was further calculated D .

[0058] The biodesulfurized rubber powder D was obtained by inoculating the Desulfuribacterium gordonii DSM 44462 into 50 mL of Luria-Bertani medium containing the waste tire rubber powder at an inoculation amount of 4% v / v and culturing it freely at 25°C for 14 days.

[0059] Comparative Example 1

[0060] The S-S bond, C-S bond corrected peak area reduction rate and S element content reduction rate of the biodesulfurized rubber powder E prepared from the waste tire rubber powder in Example 1 were calculated by detection and S element content reduction rate and the desulfurization degree index DI of the biodesulfurized rubber powder E was further calculated E .

[0061] The biodesulfurized rubber powder E was obtained by inoculating the Desulfuribacterium gordonii DSM 44462 into 50 mL of Luria-Bertani medium containing the waste tire rubber powder at an inoculation amount of 4% v / v and culturing it freely at 20°C for 7 days.

[0062] Comparative Example 2

[0063] The S-S bond, C-S bond corrected peak area reduction rate and S element content reduction rate of the biodesulfurized rubber powder F prepared from the waste tire rubber powder in Example 1 were calculated by detection and S element content reduction rate and the desulfurization degree index DI of the biodesulfurized rubber powder F was further calculated F .

[0064] The biodesulfurized rubber powder F was obtained by inoculating the Desulfuribacterium gordonii DSM 44462 into 50 mL of Luria-Bertani medium containing the waste tire rubber powder at an inoculation amount of 4% v / v and culturing it freely at 20°C for 11 days.

[0065] Comparative Example 3

[0066] The S-S bond, C-S bond corrected peak area reduction rate and S element content reduction rate of the biodesulfurized rubber powder G prepared from the waste tire rubber powder in Example 1 were calculated by detection and S element content reduction rate Further, the desulfurization degree index DI of the biodesulfurized rubber powder G was calculated. G .

[0067] The biodesulfurized rubber powder G was obtained by inoculating the Desulfuribacterium gordonii DSM 44462 into 50 mL of Luria-Bertani medium containing the waste tire rubber powder at an inoculation amount of 4% v / v, and then culturing it freely at 20°C for 14 days.

[0068] Comparative Example 4

[0069] The biodesulfurized rubber powder H was prepared from the waste tire rubber powder in Example 1, and the S-S bond, C-S bond corrected peak area reduction rate of the biodesulfurized rubber powder H was calculated by detection and the S element content reduction rate Further, the desulfurization degree index DI of the biodesulfurized rubber powder H was calculated. H .

[0070] The biodesulfurized rubber powder H was obtained by inoculating the Desulfuribacterium gordonii DSM 44462 into 50 mL of Luria-Bertani medium containing the waste tire rubber powder at an inoculation amount of 4% v / v, and then culturing it freely at 20°C for 7 days.

[0071] Desulfurization degree evaluation test

[0072] The biodesulfurized rubber powder samples provided in Examples 2-5 and Comparative Examples 1-4 were subjected to a desulfurization degree test.

[0073] 1. Fourier infrared spectroscopy attenuated total reflection test

[0074] 0.1 g of the rubber powder sample was weighed with a sampling spoon, spread on a glass slide, and pressed to make a sample. The Fourier transform infrared spectrometer was used to perform an attenuated total reflection test (ATR) on the rubber powder sample. The infrared spectra of some examples are shown in FIG. 1, and the S-S bond, C-S bond corrected peak area reduction rate of the biodesulfurized rubber powder samples of each example and comparative example was calculated, respectively. Figure 2 The results are shown in Table 1.

[0075] Table 1 S-S bond, C-S bond corrected peak area reduction rate

[0076]

[0077]

[0078] 2. EA elemental analysis test

[0079] ​The EA3000 elemental analyzer was used, the Turbo Flash dynamic combustion technology was used, and the appropriate oxygen volume was set to make the oxygen supply combustion complete under controllable, independent, and programmed quantitative conditions. The S element content of the biological desulfurization rubber powder samples of Examples 2-5 and Comparative Examples 1-4 and the waste tire rubber powder of Example 1 was tested. The S element content test results are shown in Table 2 below, and the S element reduction rate test results are shown in Table 3 below. Figure 3

[0080] Table 2 S element content and reduction rate

[0081] Type S，％ [R ΔS , %]] Example 1 2.496 0 Example 2 0.917 63.26 Example 3 0.830 66.75 Example 4 0.930 62.74 Example 5 0.627 74.88 Comparative Example 1 2.384 4.49 Comparative Example 2 2.299 7.89 Comparative Example 3 2.246 10.02 Comparative Example 4 2.213 11.34

[0082] 3. DI value calculation

[0083] According to the formula The desulfurization degree index DI of the biological desulfurization rubber powder samples of Examples 2-5 and Comparative Examples 1-4 was calculated and is shown in Table 3 below.

[0084] Table 3 Desulfurization degree index

[0085] Type DI, % Example 1 0 Example 2 49.74 Example 3 65.68 Example 4 49.24 Example 5 75.30 Comparative Example 1 10.26 Comparative Example 2 15.01 Comparative Example 3 18.37 Comparative Example 4 20.09

[0086] From the DI value, it can be seen that the desulfurization degree of the biological desulfurization rubber powder of Comparative Examples 1, 2, 3, and 4 is low, belonging to I-grade desulfurization level; the desulfurization degree of the biological desulfurization rubber powder of Example 2 and Example 4 is moderate, belonging to II-grade desulfurization level; the desulfurization degree of the biological desulfurization rubber powder of Example 3 and Example 5 is large, belonging to III-grade desulfurization level. The biological desulfurization rubber powder of Example 3 and Example 5 reaching III-grade desulfurization level has the most prominent effect on improving the high-temperature performance and storage stability of modified asphalt.

[0087] 4. Modified asphalt was prepared using the biological desulfurization rubber powder samples of Examples 2-5 and Comparative Examples 1-4 and the waste tire rubber powder of Example 1, and basic physical property tests were performed to explore the optimal desulfurization level of the biological desulfurization rubber powder for preparing modified asphalt. The results are shown in Table 4 below.

[0088] The preparation of the above modified asphalt is as follows:

[0089] 1) 70# base asphalt was placed in an oven and heated to a molten state at 170°C, 200g was weighed into an iron tank and placed on a high-speed shearing machine heating table.

[0090] 2) 30g of any one of the biological desulfurization rubber powder samples of Examples 2-5 and Comparative Examples 1-4 and the waste tire rubber powder of Example 1 was added to the iron tank, and sheared at 2000r / min low speed for 15min, and then sheared at 5000r / min high speed for 60min.

[0091] ​3) After shearing, place in the oven at 170℃ for 1h to swell, and after swelling, the preparation of waste tire rubber powder or biodesulfurized rubber powder with different DI values is completed.

[0092] Table 4 Performance test results of modified asphalt

[0093]

[0094] According to the performance verification test, it can be found that the softening point and rotary viscosity of the biodesulfurized rubber powder modified asphalt increase with the increase of DI value, that is, the high temperature performance of the biodesulfurized rubber powder modified asphalt as a whole increases with the increase of desulfurization degree. The performance improvement effect of the biodesulfurized rubber powder sample of III desulfurization grade on the modified asphalt is significantly better than that of I desulfurization grade. In addition, with the increase of DI value, the segregation softening point difference of the biodesulfurized rubber powder modified asphalt gradually decreases, and the storage stability gradually improves. The segregation softening point difference of the biodesulfurized rubber powder modified asphalt of I desulfurization grade is higher than 2℃, and the segregation softening point difference of the biodesulfurized rubber powder modified asphalt of III desulfurization grade is only maintained at about 1℃, which proves that the III desulfurized rubber powder is the most effective in improving the storage stability of the modified asphalt.

[0095] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for evaluating the degree of desulfurization of a bio-desulfurized rubber powder for a modified asphalt, characterized by, The method comprises the following steps: (1) respectively performing sheeting treatment and EA element analysis test pretreatment on the waste tire rubber powder, to obtain Fourier infrared spectrum attenuated total reflection sheeting test piece and EA element analysis test piece; (2) performing attenuated total reflection test on the Fourier infrared spectrum attenuated total reflection sheeting test piece, to obtain the transmittance infrared spectrum curve of the waste tire rubber powder; The S-S bond and C-S bond characteristic peaks in the transmittance infrared spectrum curve are identified, and the S-S bond and C-S bond corrected peak areas of the waste tire rubber powder are calculated, and are respectively denoted as (3) performing EA element analysis test on the EA element analysis test piece, to obtain the S element content of the waste tire rubber powder, denoted as S0; (4) The waste tire rubber powder is subjected to desulfurization treatment to obtain a biological desulfurized rubber powder; the biological desulfurized rubber powder is subjected to the same treatment in the manner of steps (1)-(3) to obtain a biological desulfurized rubber powder S-S bond, C-S bond correction peak area and S element content, which are respectively denoted as and S1; (5) Calculate the reduction rates of S-S bond, C-S bond correction peak area and S element content of the biological desulfurized rubber powder based on the waste tire rubber powder, respectively recorded as and R ΔS ; (6) the reduction rate of the peak area of the S-S bond and the C-S bond of the biodesulfurized rubber powder and the reduction rate R of the S element content ΔS The desulfurization degree index DI value of the biodesulfurized rubber powder is calculated by substituting the DI value calculation formula, and the desulfurization degree of the biodesulfurized rubber powder is evaluated according to the DI value. I-grade desulfurization degree grade: DI < 30; II-grade desulfurization degree grade: 30 ≤ DI ≤ 60; III-grade desulfurization degree grade: DI > 60.

2. The method for evaluating the degree of desulfurization of bio-desulfurized rubber powder for modified asphalt according to claim 1, characterized by, In step (2), the Fourier infrared spectrum attenuated total reflection wave number range is 400-4000 cm -1 , and the scanning number is 32.

3. The method for evaluating the degree of desulfurization of bio-desulfurized rubber powder for modified asphalt according to claim 1, characterized by, In step (2), in the waste tire rubber powder, corresponding to the S-S bond at an infrared spectrum wave number of 509 cm -1 corresponding to the peak area of the place, corresponding to the C-S bond at an infrared spectrum wave number of 775 cm -1 corresponding to the peak area of the place.

4. The method for evaluating the degree of desulfurization of bio-desulfurized rubber powder for modified asphalt according to claim 1, characterized by, In step (3), the analysis time of the EA element analysis test is less than 5 min.

5. The method for evaluating the degree of desulfurization of bio-desulfurized rubber powder for modified asphalt according to claim 1, characterized by, In step (4), in the biodesulfurized rubber powder, the corrected peak area corresponding to the S-S bond at an infrared spectrum wave number of 509 cm -1 at the place, the corrected peak area corresponding to the C-S bond at an infrared spectrum wave number of 775 cm -1 at the place.

6. The method for evaluating the degree of desulfurization of bio-desulfurized rubber powder for modified asphalt according to claim 1, characterized by, In step (4), the desulfurization treatment is specifically as follows: the desulfurizing Gordonia is inoculated into 50 mL of culture medium containing the waste tire rubber powder for free culture, and finally the biological desulfurized rubber powder is obtained.

7. The method for evaluating the degree of desulfurization of bio-desulfurized rubber powder for modified asphalt according to claim 6, characterized by, The culture temperature is selected to be 20-30 DEG C, the culture time is selected to be 7-14 days, and the inoculation amount of the desulfurizing Gordonia is selected to be 2-4% v / v.

8. The method for evaluating the degree of desulfurization of bio-desulfurized rubber powder for modified asphalt according to claim 1, characterized by, In step (5), and R ΔS The calculation formula is as follows:

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