A Comprehensive Study on the Rheological Properties of Desulfurized Rubberized Asphalt and Establishment of Micro-Scale Mechanical Models

A Comprehensive Study on the Rheological Properties of Desulfurized Rubberized Asphalt and Establishment of Micro-Scale Mechanical Models | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article A Comprehensive Study on the Rheological Properties of Desulfurized Rubberized Asphalt and Establishment of Micro-Scale Mechanical Models Yingjie Chang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4968837/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 07 Nov, 2024 Read the published version in Scientific Reports → Version 1 posted 16 You are reading this latest preprint version Abstract In this study, the complex relationship between the mechanical properties of desulfurized rubberized asphalt and the characteristics of its component material is explored, with the aim to establish a micro-scale mechanical model for desulfurized rubberized asphalt. Three types of desulfurized rubber powders with different Menni viscosities were used to prepare desulfurized rubberized asphalt, and its rheological properties were evaluated through high-temperature multi-stress creep recovery test (MSCR) test, medium-temperature linear amplitude scanning (LAS) test, and low-temperature bending beam rheology (BBR) test. Through frequency scanning tests, combined with the principle of time-temperature equivalence and the corresponding mathematical model, the dynamic modulus of the matrix asphalt and desulfurized rubber powder was determined, leading to the establishment of a micro-scale mechanical model for desulfurized rubberized asphalt. The results indicate that the high-temperature performance indicators of desulfurized rubberized asphalt are highly sensitive to the degree of desulfurization. As the degree of desulfurization of the rubber powder increases, the fatigue damage rate of asphalt gradually reduces, and its fatigue life improves. Specifically, the asphalt sample modified using desulfurized rubber powder with a Menni viscosity of 40 exhibits the best low-temperature cracking performance. The increase in the degree of desulfurization promotes better dissolution of rubber in the asphalt, and the size of the rubber powder affects its interaction with the asphalt. Among the powders, the rubber powder with a size of 0.15 mm has the largest specific surface area, leading to rapid changes in the concentration over time. In addition, the Mori-Tanaka (MT) and two-layer built-in (TLB) models are found to be effective for predicting the performance of desulfurized rubberized asphalt. Using the gray correlation method, comprehensive indicators for high-, medium-, and low-temperature performance are established. The results reveal that the desulfurized rubber powder with a Menni viscosity of 60 exhibits the highest comprehensive performance indicators. Thus, for high-temperature regions, the use of 60 desulfurized rubber powder with a Menni viscosity of 60 is recommended for asphalt preparation. Physical sciences/Engineering/Civil engineering Physical sciences/Materials science Micro-scale mechanical model Desulfurized rubberized asphalt Degree of desulfurization Rheological properties Solubility Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 1. Introduction Rubber-modified asphalt, also called rubberized asphalt, is a composite material made from a chemical reaction between rubber powder and base asphalt binder. It has been observed that the incomplete reaction between rubber powder and asphalt often leads to poor stability at high temperatures [ 1 , 2 ]. Therefore, to ensure complete integration, the preparation temperature often exceed 185 °C [ 3 ]. However, under high-temperature conditions, the rubber powder is prone to oxidation, generating SO 2 and causing environmental pollution [ 4 , 5 ]. Reducing the sulfur content in the rubber powder can effectively inhibit the sulfide emissions from modified asphalt [ 6 ], but the process of mixing modified asphalt with desulfurized rubber powder is often accompanied by physico-chemical changes. Further, desulfurized rubber powder absorbs the lightweight components of asphalt, resulting in volume dissolution, which can destroy the cross-linked network structure of rubber [ 7 ], altering some properties of asphalt. Although several studies have been conducted on the relationship between the degree of desulfurization of rubber powder and asphalt [ 8 , 9 ], the application of micro-scale mechanical models to describe the mechanical properties of desulfurized rubberized asphalt has been rarely explored. To this end, this study proposes viewing desulfurized rubberized asphalt as a two-phase composite material, where asphalt serves as the matrix phase [ 10 ] and desulfurized rubber powder acts as the intercalated phase in asphalt. The aim is to establish a micro-scale mechanical model for desulfurized rubberized asphalt. In this study, we have first selected desulfurized rubberized asphalt in three states: as-is, short-term aged, and long-term aged [ 11 , 12 ]. The high-, medium-, and low-temperature rheological performances of the desulfurized rubberized asphalt samples are characterized by multi-stress creep recovery (MSCR) [ 13 ], linear amplitude scanning (LAS) [ 14 ], and bending beam rheology (BBR) [ 15 , 16 ] tests, respectively [ 17 ]. Next, the dynamic modulus values of matrix asphalt and desulfurized rubber powder are obtained through frequency scanning tests, applying the principle of time-temperature equivalence of asphalt and the corresponding mathematical model [ 18 , 19 ]. The master curves for both general rubberized asphalt and desulfurized rubberized asphalt are established to compare their dynamic mechanical properties [ 20 ]. Finally, the modulus and Poisson's ratio of desulfurized rubber powder and asphalt obtained from the test are used to establish a micro-scale mechanical model, and the prediction accuracy of the model is verified by comparing its results with those from indoor tests [ 21 ]. Overall, this study provides insights into the effect of the degree of desulfurization on the rheological properties of rubberized asphalt, which can assist in identifying a suitable micro-scale mechanical model for desulfurized rubberized asphalt. 2. Preparation and experimental design of desulfurized rubberized asphalt 2.1 Materials 2.1.1 Asphalt and desulphurized powder PEN-70 asphalt, supplied by China National Petroleum Corporation, was utilized as the matrix asphalt. Its performance indexes are listed in Table 1 . Table 1 General technical specifications of matrix asphalt Index Value Penetration at 25 ℃, 100 g, 5 s, 0.1 mm 67.9 Ductility at 10 ℃ 27.1 cm Softening point 48.3 ℃ Quality loss −0.1% Residual penetration ratio at 25 ℃ 73.2% Residual ductility at 10 ℃ 6.3 cm Waste tires were recycled using a homemade twin-screw extrusion compressor from Jiangsu Zhonghong Environmental Protection Technology Co., China. Rubber powder with an average particle size of 40 mesh was produced by grinding scrap rubber at room temperature [ 22 ]. The main components of the rubber powder were 33.0% carbon black, 40.0% natural rubber, and 13.0% synthetic rubber, and approximately 14% additional rubber additives. During the preparation of desulfurized rubber powder, the temperatures were controlled at 240, 260, and 280 °C. The Menni viscosities of the desulfurized rubber powder at these temperatures were 39.5 ML1 + 10@100 °C, 58.9 ML1 + 10@100 °C, and 78.3 ML + 10@100 °C, respectively. The asphalt samples were labeled as ML40, ML60, and ML80 according to their Menni viscosities. 2.1.2 Preparation of desulphurized rubberized asphalt (1) Preparation method The wet process was employed to prepare rubberized asphalt [ 23 ]. The main instruments used included a high-speed shear, electric stirrer, electric heating jacket, thermometer, and glass rod. The shear rate of the high-speed shear ranged from 0 to 12,000 r/min. Firstly, the substrate asphalt was heated to 175 °C and mixed with a specified mass fraction of rubber powder. This mixture was then stirred with an electric stirrer at a low speed of 500 rpm for nearly 15 min. Subsequently, the modified asphalt, also heated to approximately 175 °C and mixed with the same mass fraction of rubber powder, was stirred at a low speed of 500 rpm for nearly 15 min with an electric stirrer. Afterwards, the high-speed shear was activated at 5000 rpm and maintained at a specific temperature for a set duration. The modified asphalt was then placed in an oven at 160 °C for 45 min until the bubbles disappeared, yielding modified asphalt samples for performance testing. Next, the asphalt samples were poured into a small sample tank and stored under appropriate conditions for subsequent testing. The prepared general rubberized asphalt was designated CRMA, while the desulfurized rubberized asphalt samples, categorized by different Menni viscosities, were denoted as ML40MA, ML60MA, and ML80MA. (2) Three major indicators of rubberized asphalt The three types of prepared rubberized asphalt samples were tested for three main indicators, and the test results are presented in Table 2 . Table 2 Performance indexes of rubberized asphalt before and after aging Index Asphalt before aging Asphalt after aging CRMA ML40 ML60 ML80 CRMA ML40 ML60 ML80 Penetration at 25 ℃, 100 g, 5 s (0.1 mm) 69.2 53.2 53.9 54.1 53.1 42.9 42.2 41.1 Ductility at 10 ℃ (cm) 20.1 17.2 15.7 10.6 13.1 11.6 11.1 7.7 Softening point (℃) 68.2 64.5 62.1 61.1 63.8 67 66.4 65.4 Viscosity at 135° C 4.7 7.1 5.1 4.31 5.1 8.2 7.4 6.5 Viscosity at 175° C 1.8 1.4 1.2 0.7 1.8 1.5 1.3 1.0 It can be seen in Table 2 that the needle penetration value of the three types of desulfurized rubberized asphalt samples is nearly identical, both before and after aging, and is approximately 15 mm lower than that of CRMA. This indicates that the desulfurization of rubber powder can reduce the asphalt viscosity to a certain extent, promoting better flow of asphalt. Regarding the low-temperature elongation index, desulfurized rubberized asphalt shows lower elongation than general rubberized asphalt. However the elongation index of ML40MA is similar to that of CRMA. In terms of the softening point, desulfurized rubberized asphalt demonstrates significantly better high-temperature performance than general rubberized asphalt. This performance improves further as the degree of desulfurization increases, which indicates that desulfurization can enhance the high-temperature deformation resistance of rubberized asphalt. 2.2 Performance testing of desulphurized rubberized asphalt 2.2.1 Multiple stress creep recovery test The MSCR test was performed at stress levels of 0.1 and 3.2 kPa to assess the creep and recovery characteristics of asphalt at various temperatures. The samples tested were asphalt subjected to short-term aging in a rotating film oven. The test temperatures were selected to simulate typical summer pavement conditions: 64, 70, 76, and 82 °C. Ten loading cycles were conducted at each stress level, with each loading cycle comprising a 1-s loading phase, followed by a 9-s unloading phase. The final test results were evaluated based on the average elastic recovery rate and irrecoverable flexibility. 2.2.2 Linear amplitude sweep test The LAS test consists of two segments: frequency sweep and amplitude sweep. In the frequency sweep test, a strain of 0.1% was applied across 12 test frequencies (0.2, 0.4, 0.6, 0.8, 1.0, 2.0, 4.0, 6.0, 8.0, 10, 20, and 30 Hz). The damage analysis parameter α was determined by setting the test temperature and loading frequency range and conducting oscillatory shear tests at a constant amplitude. The composite dynamic modulus |G*| and phase angle δ were measured over a range of temperatures and loading frequencies. In the amplitude sweep test, conducted at a frequency of 10 Hz, the strain amplitude was linearly increased from 0–30% over 5 min, and the composite dynamic modulus |G*| and phase angle δ were recorded. The test specimens used were those subjected to short-term aging and accelerated fatigue damage. 2.2.3 Bending beam rheometer test The BBR test was carried out to evaluate the low-temperature properties of rubberized asphalt, which generally performs better in such conditions. The tests were performed at low temperatures of −12, −18, −24, and −30 °C. 2.2.4 Dissolution test of desulfurized rubber powder Rubber specimens with dimensions of 20 mm ⋅ 20 mm ⋅ 1 mm were cut and weighed. Then, they were completely immersed in closed stainless steel cups containing asphalt and placed in an oven set to 160 °C. The rubber samples were periodically removed from the oven and weighed at specific intervals. The mass absorption was determined by calculating the difference between the initial weight and the weight after immersion in asphalt [ 24 ]. After reaching the predetermined test duration, the rubber specimens were removed and allowed to stabilize for 8 min. Then, they were accurately weighed using an analytical balance. This procedure was repeated until the specimen's weight stabilized and no longer changed with the swelling time. 3 Performance testing of desulfurized rubberized asphalt 3.1 High-temperature rutting resistance of asphalt Figure 1 shows the MSCR test results, including the non-recoverable creep compliance (Jnr) and percent recovery (R) values for all asphalt samples at four different temperatures. It can be seen that the Jnr values of both CRMA and desulfurized rubberized asphalt exhibit more pronounced and uniform changes with temperature. The variation in the R value is smaller than that in the Jnr value, possibly due to the high elasticity of rubber powder particles in asphalt, which enhances the recovery ability of the rubberized asphalt. At the same temperature, regardless of the loading level, CRMA exhibits higher Jnr values and lower R values than desulfurized rubberized asphalt. This may be attributed to the ability of desulfurized rubber powder to completely expand and establish a three-dimensional (3D) cross-linked network structure with the aid of a crosslinking agent, thereby improving the deformation resistance and elastic recovery ability of asphalt. This results in enhanced high-temperature performance of desulfurized rubberized asphalt. By contrast, CRMA suffers from incomplete dissolution of rubber powder, which weakens its interaction with the asphalt, resulting in poorer high-temperature performance of asphalt. However, when the Menni viscosity of the desulfurized rubber powder is reduced to 40, ML40MA exhibits a higher Jnr value compared to ML60MA, while its R value shows the opposite trend. 3.2 Medium-temperature fatigue resistance of asphalt Based on the LAS test, the accelerated damage accumulation of asphalt samples during shear strain increase was assessed using the viscoelastic continuum damage (VECD) model for nonlinear fitting. Figure 2 displays the damage characteristic curves and fatigue life of asphalt samples at 25 °C under different strains. Overall, all four rubberized asphalt samples demonstrate superior fatigue properties. The desulfurization treatment of rubber powder does not compromise the medium-temperature fatigue resistance of general rubberized asphalt. As depicted in Fig. 2(a), with the increase in the degree of desulfurization of rubber powder, the damage characteristic curves of rubberized asphalt gradually shift to the right, indicating a decrease in the fatigue damage rate during the LAS test. This shift may be because the smaller the particle size of rubber powder, the higher the degree of desulfurization, and the more sufficient its dissolution in asphalt, which reduces the stress concentration during the loading process and improves the fatigue resistance of rubberized asphalt. By contrast, in CRMA, with the increase in deformation during the LAS test, the aggregation of rubber particles makes its microstructure more prone to fracture, thereby accelerating the modulus loss. Further, comparing the damage characteristic curves of the three desulfurized rubberized asphalts, ML40MA shows more significant damage mitigation compared to ML80MA and ML60MA. The fatigue life curves in Fig. 2(b) reveal consistent trends among CRMA and desulfurized rubberized asphalt samples at different strain levels and powder desulfurization degrees. Notably, ML40MA exhibits the longest fatigue life, likely due to the complete dissolution of the ML40 powder in asphalt. 3.3 Low-temperature cracking resistance of asphalt Figure 3 illustrates the variation in the modulus of strength (S) and creep rate (m) of four types of rubberized asphalt at temperatures of −12, −18, and −24 °C. It is evident that as the temperature decreases, the S value of all asphalt samples increases, while the m value decreases, indicating an increased risk of asphalt cracking at lower temperatures. At each temperature, ML40MA exhibits the highest S and m values, whereas ML80MA shows the lowest values. This suggests that both the S and m values of desulphurized rubberized asphalt increase with the increase in the degree of desulphurization of rubber powder. Given the complex material composition, evaluating the low-temperature performance of desulfurized rubberized asphalt solely based on S or m may be unreliable. As shown in Fig. 4 , the difference between the m-critical temperature and stiffness-critical temperature (ΔTc) for all rubberized asphalt samples is less than 0 °C, indicating that the low-temperature creep behavior of rubberized asphalt is predominantly affected by the m value. However, only the ΔTc of ML40MA does not exceed the threshold value, suggesting its optimal low-temperature cracking resistance. In addition, as the degree of desulfurization of rubber powder increases, ΔTc tends to increase gradually. This indicates that when the Menni viscosity of rubber powder is below 40, the low-temperature creep behavior of rubberized asphalt is governed by the S value. 3.4 Swelling coefficient and equilibrium concentration of the rubber powder The swelling test results for ML40 rubber powder are presented in Fig. 5 . It can be seen that the desulfurized rubber powder exhibits a linear phase during the early diffusion stage. Specifically, as the swelling time progresses, the mass change of the rubber powder initially increases linearly before stabilizing. This is because as the swelling process advances, asphalt oil, wax, and other light components gradually diffuse and penetrate into the molecular chains of rubber. This results in an increase in the concentration of light components within the rubber, reducing the concentration difference between the rubber and the surrounding asphalt, eventually reaching a state of equilibrium in swelling. Table 3 presents the swelling coefficient (D) and equilibrium swelling concentration (C ∞ ) of different types of rubber powders dissolved in asphalt. The swelling coefficients of ML80 rubber powder and CR are similar, slightly below 4⋅10 − 7 mm 2 /s, and their C ∞ value is approximately 80%. By contrast, ML40 exhibits a significantly higher swelling coefficient of 15.08⋅10 − 7 mm 2 /s, approximately five times of that of CR, and its C ∞ value is nearly twice that of CR. This indicates that desulfurizing the rubber powder to a certain degree significantly enhances its solubility in asphalt. Generally, desulfurized rubber powder exhibits better swelling ability in asphalt compared to general rubber powder, and as the degree of desulfurization increases, the powder swells more completely. This is because desulfurization disrupts more long-chain structures in the rubber powder, making its network structure less constrained and easier to dissolve in asphalt. Therefore, increasing the degree of desulfurization of rubber powder is conducive to improving its swelling capacity in asphalt. Table 3 Swelling coefficients and equilibrium swelling concentrations of different rubber powders Rubber powder type Swelling factor D×10 −7 (mm 2 /s) C ∞ (%) CR 3.74 79.60 ML80 3.87 77.53 ML60 8.41 106.20 ML40 15.06 149.15 4. Modulus analysis of desulfurized rubberized asphalt 4.1 Dynamic modulus master curve of desulfurized rubberized asphalt Figure 6 shows the variation in the shift factor with temperature. When the test temperature exceeds the reference temperature, the shift factor is less than 1, and the higher the temperature, the smaller the shift factor. At the reference temperature, the shift factor for all four types of asphalt is equal to 1. Different mixtures exhibit varying shift factors when the test temperature differs from the reference temperature. Specifically, ML80MA exhibits a higher shift factor compared to the other two types of asphalt samples, indicating that it has the highest temperature sensitivity. By contrast, ML40MA and ordinary rubberized asphalt display minimal variations in the shift factors, suggesting that the desulfurization treatment has a negligible effect on the temperature sensitivity of rubberized asphalt. 4.2 Phase modulus of desulfurized powder 4.2.1 Frequency scanning test of desulfurized rubber powder A belt punch was used to cut the desulfurized rubber into a circular sheet with a diameter of 8 mm. This sheet was then placed into a metal container with sufficient asphalt and dissolved at 180 °C for several hours. After dissolution, the rubber sheet was removed. The asphalt surface was wiped with a clean paper and allowed to dry in air until sufficiently dried. Next, the samples were tested using a dynamic shear rheometer (DSR). Finally, the dynamic modulus of the desulfurized rubber powder was obtained through frequency scanning tests, similar to those used for asphalt. In the DSR, the bottom of the parallel plate is fixed, while the upper part of the rotor swings around the central axis with an angular velocity ω. This setup allows for the determination of the composite dynamic modulus (E*) and phase angle (δ) of the specimen at different temperatures. 4.2.2 Elastic modulus of desulphurized rubber powder In this study, the desulfurized powder dissolved in asphalt for 20 h is considered to be fully dissolved, while the powder dissolved for 5 h is partially dissolved. Using ML40 powder as an example, Fig. 7 illustrates the main dynamic modulus curves of desulfurized rubber powder under varying swelling times. It can be seen that as the swelling time increases, the dynamic modulus curve becomes steeper, indicating greater temperature sensitivity of the powder. The modulus of undissolved and partially dissolved powder does not change significantly at higher frequencies, suggesting that the powder retains its elastomeric properties under insufficient dissolution. After 20 h of dissolution, the complex modulus curve of desulfurized powder exhibits a distinct "S" shape similar to that of asphalt. The modulus is smallest at low frequencies and largest at high frequencies, indicating enhanced temperature sensitivity of the powder after full dissolution in asphalt. Figure 8 shows the dynamic modulus curves of desulfurized rubber powders with different Menni viscosities after complete dissolution. The slope of these curves increases with the increase in the degree of desulfurization. Specifically, ML40 exhibits the smallest dynamic modulus at low frequency and the largest modulus at high frequency. This is consistent with the previous analysis, suggesting that desulfurization of the binder breaks the polymer cross-linking bonds, enhancing asphalt absorption and resulting in an S-shaped curve similar to that of asphalt. The dynamic modulus variation trends of ML80 powder and unswollen powder are similar, whereas those of ML60 and ML40 powders show significant differences. This indicates that the lower degree of desulphurization in ML80 powder results in a performance similar to that of normal non-desulfurized powder. 5. Prediction of rheological properties of desulfurized rubberized asphalt by micro-scale mechanical modeling 5.1 Establishment of micro-scale mechanical model Micro-scale mechanical modeling of material properties (such as Poisson's ratio, modulus, and volume fraction) and particle-particle interactions is currently the most reliable method for predicting the dynamic mechanical response of asphalt composites. The main material properties analyzed in this study include the Poisson's ratio of desulfurized rubberized asphalt (V 0 = 0.48), the Poisson's ratio of matrix asphalt (V 1 ), and the Poisson's ratio of desulfurized rubber powder (V 2 = 0.45). Four different micromechanical models and their variants are considered here: the Mori-Tanaka (MT) model, the two-layer built-in (TLB) model, the dilute model (DM), and the self-consistent (SC) model. 5.2 Performance comparison of different prediction models Figure 9 displays the prediction results of the different micromechanical models for desulfurized rubberized asphalt at three Menni viscosities, evaluated at a reference temperature of 30 °C. The prediction results of the DM and SC model are significantly different from the measured data. Further, the prediction accuracy of different models is quantitatively compared using the Pearson correlation coefficient (R). The modulus values predicted by the SC model are notably higher than the measured data at low frequencies and lower than the measured data at high frequencies. This discrepancy makes the SC model unsuitable for predicting the modulus of desulfurized rubberized asphalt. Conversely, the MT and TLB models provide more reasonable predictions, with the TLB model showing the highest fitting accuracy. However, both these models exhibit significant deviations in the low-frequency range. The low-frequency range corresponds to high temperatures, where the asphalt modulus is strongly influenced by the desulfurized rubber powder. In this study, the dosage of desulfurized rubber powder reaches 20%, indicating its substantial impact on the mechanical properties of desulfurized rubberized asphalt at low frequencies and high temperatures compared to the asphalt matrix phase. Further, both the MT and TLB models tend to underestimate the dynamic modulus of desulfurized rubberized asphalt in the low-frequency region. Conversely, at low temperatures and high frequencies, the matrix asphalt phase becomes stiffer, which significantly reduces the impact of rubber powder on the desulfurized rubberized asphalt, thereby enhancing the prediction accuracy. 5.3 Correlation analysis of Menni viscosity-rheological properties To examine the gray correlation among various macroscopic parameters of desulfurized rubber powder and desulfurized rubberized asphalt with different Menni viscosities, the Menni viscosity of desulfurized rubber powder is used as the reference sequence, denoted as X 0 (t) = {X 0 (40), X 0 (60), X 0 (80)}. The comparative sequences include the fatigue life ( N f ) of desulfurized rubberized asphalt at 1% strain level, the critical temperature \(\:\:{\varvec{T}}_{\varvec{c},\varvec{m}}\) , the composite dynamic modulus E* at \(\:{\varvec{T}}_{\varvec{c},\varvec{m}}\) , 10 Hz, and 30 °C, and the R 3.2 value at a stress level of 3.2 kPa. Specifically, \(\:{\varvec{T}}_{\varvec{c},\varvec{m}}\) is treated as an absolute value, and the gray correlation analysis is performed using N f at 1% strain, | \(\:{\varvec{T}}_{\varvec{c},\varvec{m}}\) | , E*, and R 3.2 values. Table 4 Material parameters of each desulfurized rubberized asphalt sample Desulfurized powder Menni viscosity Desulfurized rubberized asphalt \(\:{N}_{f}\) at 1% strain | \(\:{T}_{c,m}\) | \(\:{E}^{*}\) R 3.2 40 263783.6423 19 886130 69.06 60 83916.39376 17 1.79E + 06 96.52 80 33737.63584 16.5 1.03E + 06 64.79 Table 5 Gray correlation analysis results \(\:{\gamma\:}_{1}\) \(\:{\gamma\:}_{2}\) \(\:{\gamma\:}_{3}\) \(\:{\gamma\:}_{4}\) Gray correlation \(\:\:{\xi\:}_{i}\) Gray correlation coefficient 1 0.35 0.65 0.97 0.49 0.62 2 0.70 1.00 0.63 0.44 0.78 3 0.41 0.67 0.61 0.84 0.63 Table 4 presents the correlation between the Menni viscosity of the desulfurized rubber powder and various performance metrics of desulfurized rubberized asphalt, including \(\:{\varvec{N}}_{\varvec{f}}\) , | \(\:{\varvec{T}}_{\varvec{c},\varvec{m}}\) | , E*, and R 3.2 . According to Table 5 ,the correlations follow this descending order: \(\:{\varvec{\xi\:}}_{2}\) > \(\:{\varvec{\xi\:}}_{3}\) > \(\:{\varvec{\xi\:}}_{1}\) , suggesting that the desulfurized rubberized asphalt with a Menni viscosity of 60 exhibits the best overall performance. Although the indoor test results indicate that desulfurized rubberized asphalt with a Menni viscosity of 40 exhibits the best performance at low to medium temperatures, its high-temperature performance is poor. Notably, achieving good high-temperature performance is crucial for practical applications. The MSCR test results reveal that ML60MA offers the best high-temperature performance, which is consistent with the composite performance indicator values. Therefore, it is recommended to use desulfurized rubber powder with a Menni viscosity to 60 to meet the performance requirements of asphalt pavements in high-temperature regions during summer. 6. Conclusions Three kinds of desulfurized rubber powder with different Menni viscosities were used to prepare rubberized asphalt, and the mechanical properties of these desulfurized rubberized asphalt were comprehensively analyzed from a microscopic perspective, considering the complex relationships among material components. The key findings of the study are summarized as follows: Fatigue resistance and low-temperature performance : The MSCR test demonstrated that the degree of desulfurization of rubber powder significantly impacted the fatigue resistance of asphalt at medium temperatures. Specifically, with the increase in the degree of desulfurization, the fatigue damage rate of asphalt gradually reduced, leading to an extended fatigue life. Notably, asphalt prepared using desulfurized rubber powder with a Menni viscosity of 40 exhibited the best low-temperature crack resistance. Swelling behavior : The type and size of the rubber powder affected its swelling in asphalt. A higher degree of desulfurization resulted in simpler long-chain structures in the rubber powder, enhancing asphalt absorption. The powder size also influenced its interaction with asphalt, and the powder with a size of 0.15 mm showed the largest surface area and thus the strongest interaction. Dynamic modulus : The dynamic modulus values of desulfurized rubberized asphalt were higher than those of original asphalt at low frequencies and lower at high frequencies. This indicated that the incorporation of desulfurized rubber powder improved both the high- and low-temperature performance of the asphalt, with the performance enhancing as the degree of desulfurization increased. The main dynamic modulus curves of desulfurized rubber with different degrees of swelling and desulfurization showed significant differences, and steeper curves were observed as both factors increased. After 20 h of swelling, the complex modulus curve of desulfurized rubber exhibited a distinct "S" shape similar to that of asphalt. Model prediction accuracy : The MT and TLB models demonstrated higher prediction accuracy for the complex modulus of desulfurized rubberized asphalt in the high-frequency region. This was due to the significant effect of desulfurized rubber powder on the modulus of asphalt at high temperatures. However, the intrinsic limitations of the two models resulted in a large deviation between the predicted and measured results in the low-frequency range. Recommendation for asphalt production : Based on the above findings, it is recommended to use desulfurized rubber powder with a Menni viscosity of 60 for the actual production of rubberized asphalt in high-temperature areas to achieve optimal comprehensive performance. Declarations Author Contribution Author C provided conceptualization, methodology, data management, writing-manuscript preparation, visualization, investigation, supervision, software, validation, writing-review, and editing. Should you have any questions or data requirements, please contact author Yingjie Chang at [email protected] . Acknowledgments We thank all the reviewers for taking the necessary time and effort to review this manuscript. Additionally, we would like to thank MJEditor ( www.mjeditor.com ) for providing linguistic assistance during the preparation of this manuscript. References Huiyun, X. I. A. et al. Optimization of composition and performance of composite modified asphalt sealant[J]. J. South. China Univ. Technology: Nat. Sci. Ed. 51 (6), 136–145. 10.12141/j.issn.1000-565X (2023). 220540.(in Chinese). Xiaofeng, W. A. N. G. & Rongji, C. A. O. Modification mechanism of rubberized asphalt[J]. J. Chang'an University: Nat. Sci. Ed. 31 (2), 6 (2011). DOI:CNKI:SUN:XAGL.0.2011-02-003.(in Chinese). Kim, H. H. & Lee, S. J. Evaluation of rubber influence on cracking resistance of crumb rubber modified binders with wax additives[J]. Can. J. Civ. Eng. 10.1139/cjce-2014-0510 (2016). Yu, B. et al. Evaluation of plastic–rubberized asphalt: Engineering property and environmental concern[J]. Constr. Building Mater. 71 (nov.30), 416–424. 10.1016/j.conbuildmat.2014.08.075 (2014). Wang, S., Cheng, D. & Xiao, F. Recent developments in the application of chemical approaches to rubberized asphalt[J]. Constr. Build. Mater. 131 (JAN.30), 101–113. 10.1016/j.conbuildmat.2016.11.077 (2017). Gao Lei, W. Research on the preparation and performance of composite high viscosity and high elasticity modified asphalt based on orthogonal test[J]. Highway . 66 (12), 7 (2021). (in Chinese). Lyu, L. et al. Bio-modified rubberized asphalt binder: A clean, sustainable approach to recycle rubber into construction[J]. J. Clean. Prod. 345 , 131151–. 10.1016/j.jclepro.2022.131151 (2022). Hua, T. A. N. et al. Research on the viscoelastic properties of composite modified rubberized asphalt based on rheology[J]. Journal of Civil Engineering, 50(1):8. DOI:CNKI:SUN:TMGC.0.2017-01-014. (in Chinese) (2017). Ming, Z. H. A. N. G., Junqing, W. U. & Junliang, L. I. U. Research progress of waste rubber gum pulverization process and recycling of rubber powder[J]. Rubber Ind. 67 (1), 7. 10.12136/j.issn.1000-890X.2020.01.0003 (2020). (in Chinese). Zhang, B. et al. A Study on Physical and Rheological Properties of Rubberized Bitumen Modified by Different Methods[J]. Materials . 12 (21). 10.3390/ma12213538 (2019). Nettleton, M. A. The applications of unsteady, multi-dimensional studies of detonation waves to ram accelerators[J]. Shock Waves . 10 (1), 9–22. 10.1007/s001930050175 (2000). Guangtai, Z. H. A. N. G., Shuo, F. A. N. G. & Fen, Y. E. Research on rheological properties of asphalt modified by twin-screw extruded rubber powder[J]. Chin. J. Highway . 32 (5), 8. 10.19721/j.cnki.1001-7372.2019.05.005 (2019). (in Chinese). Zhen, Y. A. O. et al. Comprehensive performance evaluation and modification mechanism of various wet rubber-modified asphalt[J]. Mater. Herald . 36 (16), 7 (2022). (in Chinese). Zhao, M. & Dong, R. Reaction mechanism and rheological properties of waste cooking oil pre-desulfurized crumb tire rubber/SBS composite modified asphalt[J]. Constr. Build. Mater. 274 (6), 122083. 10.1016/j.conbuildmat.2020.122083 (2021). Xiaojuan, L. I., Xijuan, X. U. & Qingqing, W. A. N. G. Study on the performance of desulfurized rubber-modified asphalt with different matrix asphalt[J]. Chin. Foreign Highway , (5):156–160. (2022). (in Chinese). Li Chaoli, H. D. P. E. D. Rubber Powder Composite Modified Asphalt Preparation and Its Road Performance [D]. Hunan University [2024-06-27]. (in Chinese). Yiwen, Y. A. N. G., Hao, Y. U. A. N. & Tao, M. A. Dissolution principle and road performance of desulfurized rubberized asphalt[J]. Highway and Transportation Science and Technology, 29(2):35–39. DOI:103969/jissn1002-0268201202 007. (in Chinese) (2012). Zhu, D. B. Experimental study on desulfurized rubberized asphalt mastic [J]. Highway Engineering, 38(4): 4. DOI:CNKI:SUN:ZNGL.0.2013-04-027. (in Chinese) (2013). Xiaofeng, W. A. N. G. et al. Characterization of properties of different types of rubber powder and SBS composite modified asphalt[J]. Silicate Bulletin, 38(11): 8. DOI:CNKI:SUN:GSYT.0.2019-11-050. (in Chinese) (2019). Fang, Y. et al. Rheological Property Evaluation and Microreaction Mechanism of rubberized asphalt, Desulfurized rubberized asphalt, and Their Composites[J]. J. Mater. Civ. Eng. 33 , 04021100. 10.1061/(ASCE)MT.1943-5533.0003688 (2021). Shuo, F. A. N. G., Guangtai, Z. H. A. N. G. & Fen, Y. E. Research on rheological and microscopic properties of asphalt with vegetable oil activated gum powder[J]. Highway Eng. 43 (4), 5. 10.3969/j.issn.1674-0610.2018.04.023 (2018). (in Chinese). Tao, M. A. et al. A review of the development of gum powder applied to asphalt modification technology[J]. Chin. J. Highway . 34 (10), 16. 10.19721/j.cnki.1001-7372.2021.10.001 (2021). (in Chinese). Zhou, Z. Analysis of micro-morphology and effect of asphalt modification in dry mix rubberized asphalt mixtures[J]. Highway . 63 (5), 4 (2018). (in Chinese). Chaoyang, G. U. O., Zhaoyi, H. E. & Yang, C. A. O. Research on modification mechanism of asphalt modified by waste tire rubber powder[J]. Chinese and Foreign Highway, DOI: JournalArticle/5aebe7d4c095d710d4f80306. (in Chinese) (2008). Jose, R. et al. Micromechanical shear modulus modeling of activated crumb rubber modified asphalt cements[J]. Constr. Building Mater. 10.1016/j.conbuildmat.2017.05.208 (2017). Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 07 Nov, 2024 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 03 Oct, 2024 Reviews received at journal 01 Oct, 2024 Reviews received at journal 19 Sep, 2024 Reviews received at journal 19 Sep, 2024 Reviews received at journal 13 Sep, 2024 Reviews received at journal 09 Sep, 2024 Reviewers agreed at journal 09 Sep, 2024 Reviewers agreed at journal 09 Sep, 2024 Reviewers agreed at journal 08 Sep, 2024 Reviewers agreed at journal 08 Sep, 2024 Reviewers agreed at journal 08 Sep, 2024 Reviewers invited by journal 08 Sep, 2024 Editor assigned by journal 08 Sep, 2024 Editor invited by journal 06 Sep, 2024 Submission checks completed at journal 03 Sep, 2024 First submitted to journal 24 Aug, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4968837","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":361713228,"identity":"2aa32c5c-add2-495c-aa58-d56910a0321a","order_by":0,"name":"Yingjie Chang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA9klEQVRIiWNgGAWjYHACNijN//33nwoJOXkStDAYSPCcsTA2bCBJC29bRSLDAQLq5WfkHnvwc0etnDn/ggQDyXkSCYwNzA8f3cCjxeBGXrph75njxpYzHhxIMNwmkcfOwGZsnINPi0SOGdA9xxI33DjYcCBxm0QxYwMPmzQ+LfIzcswk/7Ydq99w4zBjw8E5EokNBwhoYbiRYybN21aTYHC+jZmxsYEILQZn3phJy7YdMNxwg4eNmeGYhLFhMwG/yLcDHfa2rU7e4PwZoJaaOjl59uaHj/E6DAIOMzBIJEDZzISVg0AdML0cIE7pKBgFo2AUjDwAAHGZTEOzQfwKAAAAAElFTkSuQmCC","orcid":"","institution":"Shaanxi Province Land Engineering Construction Group Co., Ltd","correspondingAuthor":true,"prefix":"","firstName":"Yingjie","middleName":"","lastName":"Chang","suffix":""}],"badges":[],"createdAt":"2024-08-24 11:03:53","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4968837/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4968837/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-024-77132-z","type":"published","date":"2024-11-07T15:57:03+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":65920014,"identity":"c594dbe6-b325-4e78-bc17-8c814a77652a","added_by":"auto","created_at":"2024-10-04 11:38:35","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":863844,"visible":true,"origin":"","legend":"\u003cp\u003eMSCR test results\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4968837/v1/5453b64a16018f82348fe687.jpeg"},{"id":65919498,"identity":"2531cb29-ae01-4ba7-9e75-919017441b5c","added_by":"auto","created_at":"2024-10-04 11:30:35","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":345319,"visible":true,"origin":"","legend":"\u003cp\u003eLAS test results\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4968837/v1/00a6d30ec662a36d5239f723.png"},{"id":65918529,"identity":"1c3cd80b-9950-4efe-840b-7c673ea0e4b3","added_by":"auto","created_at":"2024-10-04 11:22:35","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":69237,"visible":true,"origin":"","legend":"\u003cp\u003eBBR test results\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-4968837/v1/be7de32de3190998fdbc0455.png"},{"id":65918526,"identity":"3a9c6ed0-2304-4fb6-9a3e-163ce804fb47","added_by":"auto","created_at":"2024-10-04 11:22:35","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":26047,"visible":true,"origin":"","legend":"\u003cp\u003eCritical low temperature\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-4968837/v1/a0bf7ead8d88e1b3041df513.png"},{"id":65919499,"identity":"dba2b4f0-0fc5-4b1e-a91d-604d68213d69","added_by":"auto","created_at":"2024-10-04 11:30:35","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":69324,"visible":true,"origin":"","legend":"\u003cp\u003eDissolution time versus rate of change in the mass of ML40 rubber powder\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-4968837/v1/c27007928de0352d760eface.png"},{"id":65918532,"identity":"e9d77d3e-ae2b-476e-9d09-d33938c0187d","added_by":"auto","created_at":"2024-10-04 11:22:35","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":56956,"visible":true,"origin":"","legend":"\u003cp\u003eShift factors for various types of asphalt\u003c/p\u003e","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-4968837/v1/002c99c578d80af78aecf6f3.png"},{"id":65920011,"identity":"ba7ad954-1944-46b9-ad87-0065f61633b7","added_by":"auto","created_at":"2024-10-04 11:38:35","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":52783,"visible":true,"origin":"","legend":"\u003cp\u003eModulus of desulfurized rubber powder under different dissolution times\u003c/p\u003e","description":"","filename":"floatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-4968837/v1/ca5b7440a470a2f39ea2fd15.png"},{"id":65919500,"identity":"d16124ac-4603-424e-8a0a-13d302a1da36","added_by":"auto","created_at":"2024-10-04 11:30:35","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":54424,"visible":true,"origin":"","legend":"\u003cp\u003eDynamic modulus master curve of desulfurized rubber powder with different Menni viscosities\u003c/p\u003e","description":"","filename":"floatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-4968837/v1/807da5150e48473b9d9965ee.png"},{"id":65918534,"identity":"f4637530-7ee5-49f6-aa6a-0a0d710e738f","added_by":"auto","created_at":"2024-10-04 11:22:35","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":153165,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of the prediction accuracy between different micromechanical models\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-4968837/v1/ed30fa813e43d692504a9923.png"},{"id":68749921,"identity":"22e80505-f891-4307-9a7a-652ed024beef","added_by":"auto","created_at":"2024-11-11 16:07:35","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2372757,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4968837/v1/124fb346-fa14-483f-8169-00286e64e873.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A Comprehensive Study on the Rheological Properties of Desulfurized Rubberized Asphalt and Establishment of Micro-Scale Mechanical Models","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eRubber-modified asphalt, also called rubberized asphalt, is a composite material made from a chemical reaction between rubber powder and base asphalt binder. It has been observed that the incomplete reaction between rubber powder and asphalt often leads to poor stability at high temperatures [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Therefore, to ensure complete integration, the preparation temperature often exceed 185 \u0026deg;C [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. However, under high-temperature conditions, the rubber powder is prone to oxidation, generating SO\u003csub\u003e2\u003c/sub\u003e and causing environmental pollution [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Reducing the sulfur content in the rubber powder can effectively inhibit the sulfide emissions from modified asphalt [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], but the process of mixing modified asphalt with desulfurized rubber powder is often accompanied by physico-chemical changes. Further, desulfurized rubber powder absorbs the lightweight components of asphalt, resulting in volume dissolution, which can destroy the cross-linked network structure of rubber [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], altering some properties of asphalt. Although several studies have been conducted on the relationship between the degree of desulfurization of rubber powder and asphalt [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], the application of micro-scale mechanical models to describe the mechanical properties of desulfurized rubberized asphalt has been rarely explored. To this end, this study proposes viewing desulfurized rubberized asphalt as a two-phase composite material, where asphalt serves as the matrix phase [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] and desulfurized rubber powder acts as the intercalated phase in asphalt. The aim is to establish a micro-scale mechanical model for desulfurized rubberized asphalt.\u003c/p\u003e \u003cp\u003eIn this study, we have first selected desulfurized rubberized asphalt in three states: as-is, short-term aged, and long-term aged [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The high-, medium-, and low-temperature rheological performances of the desulfurized rubberized asphalt samples are characterized by multi-stress creep recovery (MSCR) [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], linear amplitude scanning (LAS) [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], and bending beam rheology (BBR) [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] tests, respectively [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Next, the dynamic modulus values of matrix asphalt and desulfurized rubber powder are obtained through frequency scanning tests, applying the principle of time-temperature equivalence of asphalt and the corresponding mathematical model [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The master curves for both general rubberized asphalt and desulfurized rubberized asphalt are established to compare their dynamic mechanical properties [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Finally, the modulus and Poisson's ratio of desulfurized rubber powder and asphalt obtained from the test are used to establish a micro-scale mechanical model, and the prediction accuracy of the model is verified by comparing its results with those from indoor tests [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Overall, this study provides insights into the effect of the degree of desulfurization on the rheological properties of rubberized asphalt, which can assist in identifying a suitable micro-scale mechanical model for desulfurized rubberized asphalt.\u003c/p\u003e"},{"header":"2. Preparation and experimental design of desulfurized rubberized asphalt","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1 Materials\u003c/h2\u003e \u003cdiv id=\"Sec4\" class=\"Section3\"\u003e \u003ch2\u003e2.1.1 Asphalt and desulphurized powder\u003c/h2\u003e \u003cp\u003ePEN-70 asphalt, supplied by China National Petroleum Corporation, was utilized as the matrix asphalt. Its performance indexes are listed in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eGeneral technical specifications of matrix asphalt\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIndex\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eValue\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePenetration at 25 ℃, 100 g, 5 s, 0.1 mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e67.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDuctility at 10 ℃\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e27.1 cm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSoftening point\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e48.3 ℃\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQuality loss\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026minus;0.1%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eResidual penetration ratio at 25 ℃\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e73.2%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eResidual ductility at 10 ℃\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.3 cm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eWaste tires were recycled using a homemade twin-screw extrusion compressor from Jiangsu Zhonghong Environmental Protection Technology Co., China. Rubber powder with an average particle size of 40 mesh was produced by grinding scrap rubber at room temperature [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. The main components of the rubber powder were 33.0% carbon black, 40.0% natural rubber, and 13.0% synthetic rubber, and approximately 14% additional rubber additives.\u003c/p\u003e \u003cp\u003eDuring the preparation of desulfurized rubber powder, the temperatures were controlled at 240, 260, and 280 \u0026deg;C. The Menni viscosities of the desulfurized rubber powder at these temperatures were 39.5 ML1\u0026thinsp;+\u0026thinsp;10@100 \u0026deg;C, 58.9 ML1\u0026thinsp;+\u0026thinsp;10@100 \u0026deg;C, and 78.3 ML\u0026thinsp;+\u0026thinsp;10@100 \u0026deg;C, respectively. The asphalt samples were labeled as ML40, ML60, and ML80 according to their Menni viscosities.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section3\"\u003e \u003ch2\u003e2.1.2 Preparation of desulphurized rubberized asphalt\u003c/h2\u003e \u003cp\u003e(1) Preparation method\u003c/p\u003e \u003cp\u003eThe wet process was employed to prepare rubberized asphalt [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. The main instruments used included a high-speed shear, electric stirrer, electric heating jacket, thermometer, and glass rod. The shear rate of the high-speed shear ranged from 0 to 12,000 r/min. Firstly, the substrate asphalt was heated to 175 \u0026deg;C and mixed with a specified mass fraction of rubber powder. This mixture was then stirred with an electric stirrer at a low speed of 500 rpm for nearly 15 min. Subsequently, the modified asphalt, also heated to approximately 175 \u0026deg;C and mixed with the same mass fraction of rubber powder, was stirred at a low speed of 500 rpm for nearly 15 min with an electric stirrer. Afterwards, the high-speed shear was activated at 5000 rpm and maintained at a specific temperature for a set duration. The modified asphalt was then placed in an oven at 160 \u0026deg;C for 45 min until the bubbles disappeared, yielding modified asphalt samples for performance testing. Next, the asphalt samples were poured into a small sample tank and stored under appropriate conditions for subsequent testing. The prepared general rubberized asphalt was designated CRMA, while the desulfurized rubberized asphalt samples, categorized by different Menni viscosities, were denoted as ML40MA, ML60MA, and ML80MA.\u003c/p\u003e \u003cp\u003e(2) Three major indicators of rubberized asphalt\u003c/p\u003e \u003cp\u003eThe three types of prepared rubberized asphalt samples were tested for three main indicators, and the test results are presented in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePerformance indexes of rubberized asphalt before and after aging\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eIndex\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eAsphalt before aging\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c9\" namest=\"c6\"\u003e \u003cp\u003eAsphalt after aging\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCRMA\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eML40\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eML60\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eML80\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eCRMA\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eML40\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eML60\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eML80\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePenetration at 25 ℃,\u003c/p\u003e \u003cp\u003e100 g, 5 s (0.1 mm)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e69.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e53.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e53.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e54.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e53.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e42.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e42.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e41.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDuctility at 10 ℃ (cm)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e20.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e17.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e15.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e13.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e11.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e11.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e7.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSoftening point (℃)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e68.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e64.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e62.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e61.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e63.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e66.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e65.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eViscosity at 135\u0026deg; C\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e7.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e4.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e5.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e8.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e7.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e6.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eViscosity at 175\u0026deg; C\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e1.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIt can be seen in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e that the needle penetration value of the three types of desulfurized rubberized asphalt samples is nearly identical, both before and after aging, and is approximately 15 mm lower than that of CRMA. This indicates that the desulfurization of rubber powder can reduce the asphalt viscosity to a certain extent, promoting better flow of asphalt. Regarding the low-temperature elongation index, desulfurized rubberized asphalt shows lower elongation than general rubberized asphalt. However the elongation index of ML40MA is similar to that of CRMA. In terms of the softening point, desulfurized rubberized asphalt demonstrates significantly better high-temperature performance than general rubberized asphalt. This performance improves further as the degree of desulfurization increases, which indicates that desulfurization can enhance the high-temperature deformation resistance of rubberized asphalt.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Performance testing of desulphurized rubberized asphalt\u003c/h2\u003e \u003cdiv id=\"Sec7\" class=\"Section3\"\u003e \u003ch2\u003e2.2.1 Multiple stress creep recovery test\u003c/h2\u003e \u003cp\u003eThe MSCR test was performed at stress levels of 0.1 and 3.2 kPa to assess the creep and recovery characteristics of asphalt at various temperatures. The samples tested were asphalt subjected to short-term aging in a rotating film oven. The test temperatures were selected to simulate typical summer pavement conditions: 64, 70, 76, and 82 \u0026deg;C. Ten loading cycles were conducted at each stress level, with each loading cycle comprising a 1-s loading phase, followed by a 9-s unloading phase. The final test results were evaluated based on the average elastic recovery rate and irrecoverable flexibility.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section3\"\u003e \u003ch2\u003e2.2.2 Linear amplitude sweep test\u003c/h2\u003e \u003cp\u003eThe LAS test consists of two segments: frequency sweep and amplitude sweep. In the frequency sweep test, a strain of 0.1% was applied across 12 test frequencies (0.2, 0.4, 0.6, 0.8, 1.0, 2.0, 4.0, 6.0, 8.0, 10, 20, and 30 Hz). The damage analysis parameter \u003cem\u003eα\u003c/em\u003e was determined by setting the test temperature and loading frequency range and conducting oscillatory shear tests at a constant amplitude. The composite dynamic modulus |G*| and phase angle \u003cem\u003eδ\u003c/em\u003e were measured over a range of temperatures and loading frequencies. In the amplitude sweep test, conducted at a frequency of 10 Hz, the strain amplitude was linearly increased from 0\u0026ndash;30% over 5 min, and the composite dynamic modulus |G*| and phase angle \u003cem\u003eδ\u003c/em\u003e were recorded. The test specimens used were those subjected to short-term aging and accelerated fatigue damage.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003e2.2.3 Bending beam rheometer test\u003c/h2\u003e \u003cp\u003eThe BBR test was carried out to evaluate the low-temperature properties of rubberized asphalt, which generally performs better in such conditions. The tests were performed at low temperatures of \u0026minus;12, \u0026minus;18, \u0026minus;24, and \u0026minus;30 \u0026deg;C.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e \u003ch2\u003e2.2.4 Dissolution test of desulfurized rubber powder\u003c/h2\u003e \u003cp\u003eRubber specimens with dimensions of 20 mm \u0026sdot; 20 mm \u0026sdot; 1 mm were cut and weighed. Then, they were completely immersed in closed stainless steel cups containing asphalt and placed in an oven set to 160 \u0026deg;C. The rubber samples were periodically removed from the oven and weighed at specific intervals. The mass absorption was determined by calculating the difference between the initial weight and the weight after immersion in asphalt [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. After reaching the predetermined test duration, the rubber specimens were removed and allowed to stabilize for 8 min. Then, they were accurately weighed using an analytical balance. This procedure was repeated until the specimen's weight stabilized and no longer changed with the swelling time.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"3 Performance testing of desulfurized rubberized asphalt","content":"\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\n\u003ch2\u003e3.1 High-temperature rutting resistance of asphalt\u003c/h2\u003e\n\u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e shows the MSCR test results, including the non-recoverable creep compliance (Jnr) and percent recovery (R) values for all asphalt samples at four different temperatures. It can be seen that the Jnr values of both CRMA and desulfurized rubberized asphalt exhibit more pronounced and uniform changes with temperature. The variation in the R value is smaller than that in the Jnr value, possibly due to the high elasticity of rubber powder particles in asphalt, which enhances the recovery ability of the rubberized asphalt.\u003c/p\u003e\n\u003cp\u003eAt the same temperature, regardless of the loading level, CRMA exhibits higher Jnr values and lower R values than desulfurized rubberized asphalt. This may be attributed to the ability of desulfurized rubber powder to completely expand and establish a three-dimensional (3D) cross-linked network structure with the aid of a crosslinking agent, thereby improving the deformation resistance and elastic recovery ability of asphalt. This results in enhanced high-temperature performance of desulfurized rubberized asphalt.\u003c/p\u003e\n\u003cp\u003eBy contrast, CRMA suffers from incomplete dissolution of rubber powder, which weakens its interaction with the asphalt, resulting in poorer high-temperature performance of asphalt. However, when the Menni viscosity of the desulfurized rubber powder is reduced to 40, ML40MA exhibits a higher Jnr value compared to ML60MA, while its R value shows the opposite trend.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n\u003ch2\u003e3.2 Medium-temperature fatigue resistance of asphalt\u003c/h2\u003e\n\u003cp\u003eBased on the LAS test, the accelerated damage accumulation of asphalt samples during shear strain increase was assessed using the viscoelastic continuum damage (VECD) model for nonlinear fitting. Figure\u0026nbsp;2 displays the damage characteristic curves and fatigue life of asphalt samples at 25 \u0026deg;C under different strains. Overall, all four rubberized asphalt samples demonstrate superior fatigue properties. The desulfurization treatment of rubber powder does not compromise the medium-temperature fatigue resistance of general rubberized asphalt. As depicted in Fig.\u0026nbsp;2(a), with the increase in the degree of desulfurization of rubber powder, the damage characteristic curves of rubberized asphalt gradually shift to the right, indicating a decrease in the fatigue damage rate during the LAS test. This shift may be because the smaller the particle size of rubber powder, the higher the degree of desulfurization, and the more sufficient its dissolution in asphalt, which reduces the stress concentration during the loading process and improves the fatigue resistance of rubberized asphalt.\u003c/p\u003e\n\u003cp\u003eBy contrast, in CRMA, with the increase in deformation during the LAS test, the aggregation of rubber particles makes its microstructure more prone to fracture, thereby accelerating the modulus loss. Further, comparing the damage characteristic curves of the three desulfurized rubberized asphalts, ML40MA shows more significant damage mitigation compared to ML80MA and ML60MA.\u003c/p\u003e\n\u003cp\u003eThe fatigue life curves in Fig.\u0026nbsp;2(b) reveal consistent trends among CRMA and desulfurized rubberized asphalt samples at different strain levels and powder desulfurization degrees. Notably, ML40MA exhibits the longest fatigue life, likely due to the complete dissolution of the ML40 powder in asphalt.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\n\u003ch2\u003e3.3 Low-temperature cracking resistance of asphalt\u003c/h2\u003e\n\u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e illustrates the variation in the modulus of strength (S) and creep rate (m) of four types of rubberized asphalt at temperatures of \u0026minus;12, \u0026minus;18, and \u0026minus;24 \u0026deg;C. It is evident that as the temperature decreases, the S value of all asphalt samples increases, while the m value decreases, indicating an increased risk of asphalt cracking at lower temperatures. At each temperature, ML40MA exhibits the highest S and m values, whereas ML80MA shows the lowest values. This suggests that both the S and m values of desulphurized rubberized asphalt increase with the increase in the degree of desulphurization of rubber powder. Given the complex material composition, evaluating the low-temperature performance of desulfurized rubberized asphalt solely based on S or m may be unreliable.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAs shown in Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e, the difference between the m-critical temperature and stiffness-critical temperature (\u0026Delta;Tc) for all rubberized asphalt samples is less than 0 \u0026deg;C, indicating that the low-temperature creep behavior of rubberized asphalt is predominantly affected by the m value. However, only the \u0026Delta;Tc of ML40MA does not exceed the threshold value, suggesting its optimal low-temperature cracking resistance. In addition, as the degree of desulfurization of rubber powder increases, \u0026Delta;Tc tends to increase gradually. This indicates that when the Menni viscosity of rubber powder is below 40, the low-temperature creep behavior of rubberized asphalt is governed by the S value.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e\n\u003ch2\u003e3.4 Swelling coefficient and equilibrium concentration of the rubber powder\u003c/h2\u003e\n\u003cp\u003eThe swelling test results for ML40 rubber powder are presented in Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e. It can be seen that the desulfurized rubber powder exhibits a linear phase during the early diffusion stage. Specifically, as the swelling time progresses, the mass change of the rubber powder initially increases linearly before stabilizing. This is because as the swelling process advances, asphalt oil, wax, and other light components gradually diffuse and penetrate into the molecular chains of rubber. This results in an increase in the concentration of light components within the rubber, reducing the concentration difference between the rubber and the surrounding asphalt, eventually reaching a state of equilibrium in swelling.\u003c/p\u003e\n\u003cp\u003eTable\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e presents the swelling coefficient (D) and equilibrium swelling concentration (C\u003csub\u003e\u0026infin;\u003c/sub\u003e) of different types of rubber powders dissolved in asphalt. The swelling coefficients of ML80 rubber powder and CR are similar, slightly below 4\u0026sdot;10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e mm\u003csup\u003e2\u003c/sup\u003e/s, and their C\u003csub\u003e\u0026infin;\u003c/sub\u003e value is approximately 80%. By contrast, ML40 exhibits a significantly higher swelling coefficient of 15.08\u0026sdot;10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e mm\u003csup\u003e2\u003c/sup\u003e/s, approximately five times of that of CR, and its C\u003csub\u003e\u0026infin;\u003c/sub\u003e value is nearly twice that of CR. This indicates that desulfurizing the rubber powder to a certain degree significantly enhances its solubility in asphalt. Generally, desulfurized rubber powder exhibits better swelling ability in asphalt compared to general rubber powder, and as the degree of desulfurization increases, the powder swells more completely. This is because desulfurization disrupts more long-chain structures in the rubber powder, making its network structure less constrained and easier to dissolve in asphalt. Therefore, increasing the degree of desulfurization of rubber powder is conducive to improving its swelling capacity in asphalt.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003cdiv class=\"colspec\" align=\"char\"\u003e\u0026nbsp;\u003c/div\u003e\n\u003ctable id=\"Tab3\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eSwelling coefficients and equilibrium swelling concentrations of different rubber powders\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eRubber powder type\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eSwelling factor D\u0026times;10\u003csup\u003e\u0026minus;7\u003c/sup\u003e (mm\u003csup\u003e2\u003c/sup\u003e/s)\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eC\u003csub\u003e\u0026infin;\u003c/sub\u003e (%)\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eCR\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.74\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e79.60\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eML80\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.87\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e77.53\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eML60\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e8.41\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e106.20\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eML40\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e15.06\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e149.15\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003c/div\u003e"},{"header":"4. Modulus analysis of desulfurized rubberized asphalt","content":"\u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003e4.1 Dynamic modulus master curve of desulfurized rubberized asphalt\u003c/h2\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e6\u003c/span\u003e shows the variation in the shift factor with temperature. When the test temperature exceeds the reference temperature, the shift factor is less than 1, and the higher the temperature, the smaller the shift factor. At the reference temperature, the shift factor for all four types of asphalt is equal to 1. Different mixtures exhibit varying shift factors when the test temperature differs from the reference temperature. Specifically, ML80MA exhibits a higher shift factor compared to the other two types of asphalt samples, indicating that it has the highest temperature sensitivity. By contrast, ML40MA and ordinary rubberized asphalt display minimal variations in the shift factors, suggesting that the desulfurization treatment has a negligible effect on the temperature sensitivity of rubberized asphalt.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec18\" class=\"Section2\"\u003e \u003ch2\u003e4.2 Phase modulus of desulfurized powder\u003c/h2\u003e \u003cdiv id=\"Sec19\" class=\"Section3\"\u003e \u003ch2\u003e4.2.1 Frequency scanning test of desulfurized rubber powder\u003c/h2\u003e \u003cp\u003eA belt punch was used to cut the desulfurized rubber into a circular sheet with a diameter of 8 mm. This sheet was then placed into a metal container with sufficient asphalt and dissolved at 180 \u0026deg;C for several hours. After dissolution, the rubber sheet was removed. The asphalt surface was wiped with a clean paper and allowed to dry in air until sufficiently dried. Next, the samples were tested using a dynamic shear rheometer (DSR). Finally, the dynamic modulus of the desulfurized rubber powder was obtained through frequency scanning tests, similar to those used for asphalt. In the DSR, the bottom of the parallel plate is fixed, while the upper part of the rotor swings around the central axis with an angular velocity ω. This setup allows for the determination of the composite dynamic modulus (E*) and phase angle (δ) of the specimen at different temperatures.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec20\" class=\"Section3\"\u003e \u003ch2\u003e4.2.2 Elastic modulus of desulphurized rubber powder\u003c/h2\u003e \u003cp\u003eIn this study, the desulfurized powder dissolved in asphalt for 20 h is considered to be fully dissolved, while the powder dissolved for 5 h is partially dissolved. Using ML40 powder as an example, Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e7\u003c/span\u003e illustrates the main dynamic modulus curves of desulfurized rubber powder under varying swelling times. It can be seen that as the swelling time increases, the dynamic modulus curve becomes steeper, indicating greater temperature sensitivity of the powder. The modulus of undissolved and partially dissolved powder does not change significantly at higher frequencies, suggesting that the powder retains its elastomeric properties under insufficient dissolution. After 20 h of dissolution, the complex modulus curve of desulfurized powder exhibits a distinct \"S\" shape similar to that of asphalt. The modulus is smallest at low frequencies and largest at high frequencies, indicating enhanced temperature sensitivity of the powder after full dissolution in asphalt.\u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e8\u003c/span\u003e shows the dynamic modulus curves of desulfurized rubber powders with different Menni viscosities after complete dissolution. The slope of these curves increases with the increase in the degree of desulfurization. Specifically, ML40 exhibits the smallest dynamic modulus at low frequency and the largest modulus at high frequency. This is consistent with the previous analysis, suggesting that desulfurization of the binder breaks the polymer cross-linking bonds, enhancing asphalt absorption and resulting in an S-shaped curve similar to that of asphalt.\u003c/p\u003e \u003cp\u003eThe dynamic modulus variation trends of ML80 powder and unswollen powder are similar, whereas those of ML60 and ML40 powders show significant differences. This indicates that the lower degree of desulphurization in ML80 powder results in a performance similar to that of normal non-desulfurized powder.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"5. Prediction of rheological properties of desulfurized rubberized asphalt by micro-scale mechanical modeling","content":"\u003cdiv id=\"Sec22\" class=\"Section2\"\u003e\n\u003ch2\u003e5.1 Establishment of micro-scale mechanical model\u003c/h2\u003e\n\u003cp\u003eMicro-scale mechanical modeling of material properties (such as Poisson's ratio, modulus, and volume fraction) and particle-particle interactions is currently the most reliable method for predicting the dynamic mechanical response of asphalt composites. The main material properties analyzed in this study include the Poisson's ratio of desulfurized rubberized asphalt (V\u003csub\u003e0\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;0.48), the Poisson's ratio of matrix asphalt (V\u003csub\u003e1\u003c/sub\u003e), and the Poisson's ratio of desulfurized rubber powder (V\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;0.45). Four different micromechanical models and their variants are considered here: the Mori-Tanaka (MT) model, the two-layer built-in (TLB) model, the dilute model (DM), and the self-consistent (SC) model.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec23\" class=\"Section2\"\u003e\n\u003ch2\u003e5.2 Performance comparison of different prediction models\u003c/h2\u003e\n\u003cp\u003eFigure 9 displays the prediction results of the different micromechanical models for desulfurized rubberized asphalt at three Menni viscosities, evaluated at a reference temperature of 30 \u0026deg;C. The prediction results of the DM and SC model are significantly different from the measured data. Further, the prediction accuracy of different models is quantitatively compared using the Pearson correlation coefficient (R).\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe modulus values predicted by the SC model are notably higher than the measured data at low frequencies and lower than the measured data at high frequencies. This discrepancy makes the SC model unsuitable for predicting the modulus of desulfurized rubberized asphalt. Conversely, the MT and TLB models provide more reasonable predictions, with the TLB model showing the highest fitting accuracy. However, both these models exhibit significant deviations in the low-frequency range. The low-frequency range corresponds to high temperatures, where the asphalt modulus is strongly influenced by the desulfurized rubber powder.\u003c/p\u003e\n\u003cp\u003eIn this study, the dosage of desulfurized rubber powder reaches 20%, indicating its substantial impact on the mechanical properties of desulfurized rubberized asphalt at low frequencies and high temperatures compared to the asphalt matrix phase. Further, both the MT and TLB models tend to underestimate the dynamic modulus of desulfurized rubberized asphalt in the low-frequency region. Conversely, at low temperatures and high frequencies, the matrix asphalt phase becomes stiffer, which significantly reduces the impact of rubber powder on the desulfurized rubberized asphalt, thereby enhancing the prediction accuracy.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec24\" class=\"Section2\"\u003e\n\u003ch2\u003e5.3 Correlation analysis of Menni viscosity-rheological properties\u003c/h2\u003e\n\u003cp\u003eTo examine the gray correlation among various macroscopic parameters of desulfurized rubber powder and desulfurized rubberized asphalt with different Menni viscosities, the Menni viscosity of desulfurized rubber powder is used as the reference sequence, denoted as X\u003csub\u003e0\u003c/sub\u003e (t) = {X\u003csub\u003e0\u003c/sub\u003e (40), X\u003csub\u003e0\u003c/sub\u003e (60), X\u003csub\u003e0\u003c/sub\u003e (80)}. The comparative sequences include the fatigue life (\u003cem\u003eN\u003c/em\u003e\u003csub\u003e\u003cem\u003ef\u003c/em\u003e\u003c/sub\u003e) of desulfurized rubberized asphalt at 1% strain level, the critical temperature\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\:{\\varvec{T}}_{\\varvec{c},\\varvec{m}}\\)\u003c/span\u003e\u003c/span\u003e, the composite dynamic modulus E* at \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{T}}_{\\varvec{c},\\varvec{m}}\\)\u003c/span\u003e\u003c/span\u003e, 10 Hz, and 30 \u0026deg;C, and the R\u003csub\u003e3.2\u003c/sub\u003e value at a stress level of 3.2 kPa. Specifically, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{T}}_{\\varvec{c},\\varvec{m}}\\)\u003c/span\u003e\u003c/span\u003e is treated as an absolute value, and the gray correlation analysis is performed using \u003cem\u003eN\u003c/em\u003e\u003csub\u003e\u003cem\u003ef\u003c/em\u003e\u003c/sub\u003e at 1% strain, \u003cstrong\u003e|\u003c/strong\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{T}}_{\\varvec{c},\\varvec{m}}\\)\u003c/span\u003e\u003c/span\u003e\u003cstrong\u003e|\u003c/strong\u003e, E*, and R\u003csub\u003e3.2\u003c/sub\u003e values.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n\u003cdiv class=\"colspec\" align=\"char\"\u003e\u0026nbsp;\u003c/div\u003e\n\u003ctable id=\"Tab4\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eMaterial parameters of each desulfurized rubberized asphalt sample\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eDesulfurized powder\u003c/p\u003e\n\u003cp\u003eMenni viscosity\u003c/p\u003e\n\u003c/th\u003e\n\u003cth colspan=\"4\" align=\"left\"\u003e\n\u003cp\u003eDesulfurized rubberized asphalt\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{N}_{f}\\)\u003c/span\u003e\u003c/span\u003e at 1% strain\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e|\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{T}_{c,m}\\)\u003c/span\u003e\u003c/span\u003e|\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{E}^{*}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eR\u003csub\u003e3.2\u003c/sub\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e40\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e263783.6423\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e19\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e886130\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e69.06\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e60\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e83916.39376\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e17\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1.79E\u0026thinsp;+\u0026thinsp;06\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e96.52\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e80\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e33737.63584\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e16.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1.03E\u0026thinsp;+\u0026thinsp;06\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e64.79\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n\u003cdiv class=\"colspec\" align=\"char\"\u003e\u0026nbsp;\u003c/div\u003e\n\u003cdiv class=\"colspec\" align=\"char\"\u003e\u0026nbsp;\u003c/div\u003e\n\u003ctable id=\"Tab5\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eGray correlation analysis results\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n\u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\gamma\\:}_{1}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\gamma\\:}_{2}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\gamma\\:}_{3}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\gamma\\:}_{4}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eGray correlation\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\:{\\xi\\:}_{i}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"3\" align=\"left\"\u003e\n\u003cp\u003eGray correlation coefficient\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.35\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.65\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.97\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.49\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.62\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.70\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.00\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.63\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.44\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.78\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.41\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.67\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.61\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.84\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.63\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eTable\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e presents the correlation between the Menni viscosity of the desulfurized rubber powder and various performance metrics of desulfurized rubberized asphalt, including \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{N}}_{\\varvec{f}}\\)\u003c/span\u003e\u003c/span\u003e, \u003cstrong\u003e|\u003c/strong\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{T}}_{\\varvec{c},\\varvec{m}}\\)\u003c/span\u003e\u003c/span\u003e\u003cstrong\u003e|\u003c/strong\u003e, E*, and R\u003csub\u003e3.2\u003c/sub\u003e. According to Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e,the correlations follow this descending order: \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{\\xi\\:}}_{2}\\)\u003c/span\u003e\u003c/span\u003e\u0026gt; \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{\\xi\\:}}_{3}\\)\u003c/span\u003e\u003c/span\u003e\u0026gt; \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{\\xi\\:}}_{1}\\)\u003c/span\u003e\u003c/span\u003e, suggesting that the desulfurized rubberized asphalt with a Menni viscosity of 60 exhibits the best overall performance.\u003c/p\u003e\n\u003cp\u003eAlthough the indoor test results indicate that desulfurized rubberized asphalt with a Menni viscosity of 40 exhibits the best performance at low to medium temperatures, its high-temperature performance is poor. Notably, achieving good high-temperature performance is crucial for practical applications. The MSCR test results reveal that ML60MA offers the best high-temperature performance, which is consistent with the composite performance indicator values. Therefore, it is recommended to use desulfurized rubber powder with a Menni viscosity to 60 to meet the performance requirements of asphalt pavements in high-temperature regions during summer.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"6. Conclusions","content":"\u003cp\u003eThree kinds of desulfurized rubber powder with different Menni viscosities were used to prepare rubberized asphalt, and the mechanical properties of these desulfurized rubberized asphalt were comprehensively analyzed from a microscopic perspective, considering the complex relationships among material components. The key findings of the study are summarized as follows:\u003c/p\u003e \u003cp\u003e \u003col\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eFatigue resistance and low-temperature performance\u003c/b\u003e: The MSCR test demonstrated that the degree of desulfurization of rubber powder significantly impacted the fatigue resistance of asphalt at medium temperatures. Specifically, with the increase in the degree of desulfurization, the fatigue damage rate of asphalt gradually reduced, leading to an extended fatigue life. Notably, asphalt prepared using desulfurized rubber powder with a Menni viscosity of 40 exhibited the best low-temperature crack resistance.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eSwelling behavior\u003c/b\u003e: The type and size of the rubber powder affected its swelling in asphalt. A higher degree of desulfurization resulted in simpler long-chain structures in the rubber powder, enhancing asphalt absorption. The powder size also influenced its interaction with asphalt, and the powder with a size of 0.15 mm showed the largest surface area and thus the strongest interaction.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eDynamic modulus\u003c/b\u003e: The dynamic modulus values of desulfurized rubberized asphalt were higher than those of original asphalt at low frequencies and lower at high frequencies. This indicated that the incorporation of desulfurized rubber powder improved both the high- and low-temperature performance of the asphalt, with the performance enhancing as the degree of desulfurization increased. The main dynamic modulus curves of desulfurized rubber with different degrees of swelling and desulfurization showed significant differences, and steeper curves were observed as both factors increased. After 20 h of swelling, the complex modulus curve of desulfurized rubber exhibited a distinct \"S\" shape similar to that of asphalt.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eModel prediction accuracy\u003c/b\u003e: The MT and TLB models demonstrated higher prediction accuracy for the complex modulus of desulfurized rubberized asphalt in the high-frequency region. This was due to the significant effect of desulfurized rubber powder on the modulus of asphalt at high temperatures. However, the intrinsic limitations of the two models resulted in a large deviation between the predicted and measured results in the low-frequency range.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eRecommendation for asphalt production\u003c/b\u003e: Based on the above findings, it is recommended to use desulfurized rubber powder with a Menni viscosity of 60 for the actual production of rubberized asphalt in high-temperature areas to achieve optimal comprehensive performance.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAuthor C provided conceptualization, methodology, data management, writing-manuscript preparation, visualization, investigation, supervision, software, validation, writing-review, and editing. Should you have any questions or data requirements, please contact author Yingjie Chang at [email protected].\u003c/p\u003e\u003ch2\u003eAcknowledgments\u003c/h2\u003e \u003cp\u003eWe thank all the reviewers for taking the necessary time and effort to review this manuscript. Additionally, we would like to thank MJEditor (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e\u003ca href=\"http://www.mjeditor.com\" target=\"_blank\"\u003ewww.mjeditor.com\u003c/a\u003e\u003c/span\u003e\u003cspan address=\"http://www.mjeditor.com\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e) for providing linguistic assistance during the preparation of this manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eHuiyun, X. I. A. et al. Optimization of composition and performance of composite modified asphalt sealant[J]. \u003cem\u003eJ. South. China Univ. Technology: Nat. Sci. Ed.\u003c/em\u003e \u003cb\u003e51\u003c/b\u003e (6), 136\u0026ndash;145. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.12141/j.issn.1000-565X\u003c/span\u003e\u003cspan address=\"10.12141/j.issn.1000-565X\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2023). 220540.(in Chinese).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXiaofeng, W. A. N. G. \u0026amp; Rongji, C. A. O. Modification mechanism of rubberized asphalt[J]. \u003cem\u003eJ. Chang'an University: Nat. Sci. Ed.\u003c/em\u003e \u003cb\u003e31\u003c/b\u003e (2), 6 (2011). DOI:CNKI:SUN:XAGL.0.2011-02-003.(in Chinese).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim, H. H. \u0026amp; Lee, S. J. Evaluation of rubber influence on cracking resistance of crumb rubber modified binders with wax additives[J]. \u003cem\u003eCan. J. Civ. Eng.\u003c/em\u003e \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1139/cjce-2014-0510\u003c/span\u003e\u003cspan address=\"10.1139/cjce-2014-0510\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYu, B. et al. Evaluation of plastic\u0026ndash;rubberized asphalt: Engineering property and environmental concern[J]. \u003cem\u003eConstr. Building Mater.\u003c/em\u003e \u003cb\u003e71\u003c/b\u003e (nov.30), 416\u0026ndash;424. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.conbuildmat.2014.08.075\u003c/span\u003e\u003cspan address=\"10.1016/j.conbuildmat.2014.08.075\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang, S., Cheng, D. \u0026amp; Xiao, F. Recent developments in the application of chemical approaches to rubberized asphalt[J]. \u003cem\u003eConstr. Build. Mater.\u003c/em\u003e \u003cb\u003e131\u003c/b\u003e (JAN.30), 101\u0026ndash;113. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.conbuildmat.2016.11.077\u003c/span\u003e\u003cspan address=\"10.1016/j.conbuildmat.2016.11.077\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGao Lei, W. Research on the preparation and performance of composite high viscosity and high elasticity modified asphalt based on orthogonal test[J]. \u003cem\u003eHighway\u003c/em\u003e. \u003cb\u003e66\u003c/b\u003e (12), 7 (2021). (in Chinese).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLyu, L. et al. Bio-modified rubberized asphalt binder: A clean, sustainable approach to recycle rubber into construction[J]. \u003cem\u003eJ. Clean. Prod.\u003c/em\u003e \u003cb\u003e345\u003c/b\u003e, 131151\u0026ndash;. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.jclepro.2022.131151\u003c/span\u003e\u003cspan address=\"10.1016/j.jclepro.2022.131151\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHua, T. A. N. et al. Research on the viscoelastic properties of composite modified rubberized asphalt based on rheology[J]. Journal of Civil Engineering, 50(1):8. DOI:CNKI:SUN:TMGC.0.2017-01-014. (in Chinese) (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMing, Z. H. A. N. G., Junqing, W. U. \u0026amp; Junliang, L. I. U. Research progress of waste rubber gum pulverization process and recycling of rubber powder[J]. \u003cem\u003eRubber Ind.\u003c/em\u003e \u003cb\u003e67\u003c/b\u003e (1), 7. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.12136/j.issn.1000-890X.2020.01.0003\u003c/span\u003e\u003cspan address=\"10.12136/j.issn.1000-890X.2020.01.0003\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2020). (in Chinese).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang, B. et al. A Study on Physical and Rheological Properties of Rubberized Bitumen Modified by Different Methods[J]. \u003cem\u003eMaterials\u003c/em\u003e. \u003cb\u003e12\u003c/b\u003e (21). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/ma12213538\u003c/span\u003e\u003cspan address=\"10.3390/ma12213538\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNettleton, M. A. The applications of unsteady, multi-dimensional studies of detonation waves to ram accelerators[J]. \u003cem\u003eShock Waves\u003c/em\u003e. \u003cb\u003e10\u003c/b\u003e (1), 9\u0026ndash;22. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s001930050175\u003c/span\u003e\u003cspan address=\"10.1007/s001930050175\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2000).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuangtai, Z. H. A. N. G., Shuo, F. A. N. G. \u0026amp; Fen, Y. E. Research on rheological properties of asphalt modified by twin-screw extruded rubber powder[J]. \u003cem\u003eChin. J. Highway\u003c/em\u003e. \u003cb\u003e32\u003c/b\u003e (5), 8. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.19721/j.cnki.1001-7372.2019.05.005\u003c/span\u003e\u003cspan address=\"10.19721/j.cnki.1001-7372.2019.05.005\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2019). (in Chinese).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhen, Y. A. O. et al. Comprehensive performance evaluation and modification mechanism of various wet rubber-modified asphalt[J]. \u003cem\u003eMater. Herald\u003c/em\u003e. \u003cb\u003e36\u003c/b\u003e (16), 7 (2022). (in Chinese).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao, M. \u0026amp; Dong, R. Reaction mechanism and rheological properties of waste cooking oil pre-desulfurized crumb tire rubber/SBS composite modified asphalt[J]. \u003cem\u003eConstr. Build. Mater.\u003c/em\u003e \u003cb\u003e274\u003c/b\u003e (6), 122083. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.conbuildmat.2020.122083\u003c/span\u003e\u003cspan address=\"10.1016/j.conbuildmat.2020.122083\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXiaojuan, L. I., Xijuan, X. U. \u0026amp; Qingqing, W. A. N. G. Study on the performance of desulfurized rubber-modified asphalt with different matrix asphalt[J]. \u003cem\u003eChin. Foreign Highway\u003c/em\u003e, (5):156\u0026ndash;160. (2022). (in Chinese).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi Chaoli, H. D. P. E. D. Rubber Powder Composite Modified Asphalt Preparation and Its Road Performance [D]. Hunan University [2024-06-27]. (in Chinese).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYiwen, Y. A. N. G., Hao, Y. U. A. N. \u0026amp; Tao, M. A. Dissolution principle and road performance of desulfurized rubberized asphalt[J]. Highway and Transportation Science and Technology, 29(2):35\u0026ndash;39. DOI:103969/jissn1002-0268201202 007. (in Chinese) (2012).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhu, D. B. Experimental study on desulfurized rubberized asphalt mastic [J]. Highway Engineering, 38(4): 4. DOI:CNKI:SUN:ZNGL.0.2013-04-027. (in Chinese) (2013).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXiaofeng, W. A. N. G. et al. Characterization of properties of different types of rubber powder and SBS composite modified asphalt[J]. Silicate Bulletin, 38(11): 8. DOI:CNKI:SUN:GSYT.0.2019-11-050. (in Chinese) (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFang, Y. et al. Rheological Property Evaluation and Microreaction Mechanism of rubberized asphalt, Desulfurized rubberized asphalt, and Their Composites[J]. \u003cem\u003eJ. Mater. Civ. Eng.\u003c/em\u003e \u003cb\u003e33\u003c/b\u003e, 04021100. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1061/(ASCE)MT.1943-5533.0003688\u003c/span\u003e\u003cspan address=\"10.1061/(ASCE)MT.1943-5533.0003688\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShuo, F. A. N. G., Guangtai, Z. H. A. N. G. \u0026amp; Fen, Y. E. Research on rheological and microscopic properties of asphalt with vegetable oil activated gum powder[J]. \u003cem\u003eHighway Eng.\u003c/em\u003e \u003cb\u003e43\u003c/b\u003e (4), 5. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3969/j.issn.1674-0610.2018.04.023\u003c/span\u003e\u003cspan address=\"10.3969/j.issn.1674-0610.2018.04.023\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2018). (in Chinese).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTao, M. A. et al. A review of the development of gum powder applied to asphalt modification technology[J]. \u003cem\u003eChin. J. Highway\u003c/em\u003e. \u003cb\u003e34\u003c/b\u003e (10), 16. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.19721/j.cnki.1001-7372.2021.10.001\u003c/span\u003e\u003cspan address=\"10.19721/j.cnki.1001-7372.2021.10.001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2021). (in Chinese).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhou, Z. Analysis of micro-morphology and effect of asphalt modification in dry mix rubberized asphalt mixtures[J]. \u003cem\u003eHighway\u003c/em\u003e. \u003cb\u003e63\u003c/b\u003e (5), 4 (2018). (in Chinese).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChaoyang, G. U. O., Zhaoyi, H. E. \u0026amp; Yang, C. A. O. Research on modification mechanism of asphalt modified by waste tire rubber powder[J]. Chinese and Foreign Highway, DOI: JournalArticle/5aebe7d4c095d710d4f80306. (in Chinese) (2008).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJose, R. et al. Micromechanical shear modulus modeling of activated crumb rubber modified asphalt cements[J]. \u003cem\u003eConstr. Building Mater.\u003c/em\u003e \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.conbuildmat.2017.05.208\u003c/span\u003e\u003cspan address=\"10.1016/j.conbuildmat.2017.05.208\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2017).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Micro-scale mechanical model, Desulfurized rubberized asphalt, Degree of desulfurization, Rheological properties, Solubility","lastPublishedDoi":"10.21203/rs.3.rs-4968837/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4968837/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIn this study, the complex relationship between the mechanical properties of desulfurized rubberized asphalt and the characteristics of its component material is explored, with the aim to establish a micro-scale mechanical model for desulfurized rubberized asphalt. Three types of desulfurized rubber powders with different Menni viscosities were used to prepare desulfurized rubberized asphalt, and its rheological properties were evaluated through high-temperature multi-stress creep recovery test (MSCR) test, medium-temperature linear amplitude scanning (LAS) test, and low-temperature bending beam rheology (BBR) test. Through frequency scanning tests, combined with the principle of time-temperature equivalence and the corresponding mathematical model, the dynamic modulus of the matrix asphalt and desulfurized rubber powder was determined, leading to the establishment of a micro-scale mechanical model for desulfurized rubberized asphalt. The results indicate that the high-temperature performance indicators of desulfurized rubberized asphalt are highly sensitive to the degree of desulfurization. As the degree of desulfurization of the rubber powder increases, the fatigue damage rate of asphalt gradually reduces, and its fatigue life improves. Specifically, the asphalt sample modified using desulfurized rubber powder with a Menni viscosity of 40 exhibits the best low-temperature cracking performance. The increase in the degree of desulfurization promotes better dissolution of rubber in the asphalt, and the size of the rubber powder affects its interaction with the asphalt. Among the powders, the rubber powder with a size of 0.15 mm has the largest specific surface area, leading to rapid changes in the concentration over time. In addition, the Mori-Tanaka (MT) and two-layer built-in (TLB) models are found to be effective for predicting the performance of desulfurized rubberized asphalt. Using the gray correlation method, comprehensive indicators for high-, medium-, and low-temperature performance are established. The results reveal that the desulfurized rubber powder with a Menni viscosity of 60 exhibits the highest comprehensive performance indicators. Thus, for high-temperature regions, the use of 60 desulfurized rubber powder with a Menni viscosity of 60 is recommended for asphalt preparation.\u003c/p\u003e","manuscriptTitle":"A Comprehensive Study on the Rheological Properties of Desulfurized Rubberized Asphalt and Establishment of Micro-Scale Mechanical Models","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-10-04 11:22:30","doi":"10.21203/rs.3.rs-4968837/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-10-03T05:05:54+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-10-01T06:47:23+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-09-19T15:14:19+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-09-19T14:53:18+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-09-14T00:12:31+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-09-09T14:20:03+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"92147297259710526249612214976151521904","date":"2024-09-09T05:35:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"159951495130442091098023549728714645486","date":"2024-09-09T05:00:31+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"10053219943656606016182530716101203802","date":"2024-09-09T03:09:05+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"17942557575797938631608261054014071588","date":"2024-09-09T02:15:52+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"25890039146492769149167394450244640883","date":"2024-09-09T02:10:36+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-09-09T02:04:23+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-09-09T02:01:43+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2024-09-06T06:06:07+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-09-03T11:50:38+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2024-08-24T11:02:32+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c94b0e9d-ee62-44ea-a2d9-a88a12171e9e","owner":[],"postedDate":"October 4th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":38481141,"name":"Physical sciences/Engineering/Civil engineering"},{"id":38481142,"name":"Physical sciences/Materials science"}],"tags":[],"updatedAt":"2024-11-11T16:01:05+00:00","versionOfRecord":{"articleIdentity":"rs-4968837","link":"https://doi.org/10.1038/s41598-024-77132-z","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2024-11-07 15:57:03","publishedOnDateReadable":"November 7th, 2024"},"versionCreatedAt":"2024-10-04 11:22:30","video":"","vorDoi":"10.1038/s41598-024-77132-z","vorDoiUrl":"https://doi.org/10.1038/s41598-024-77132-z","workflowStages":[]},"version":"v1","identity":"rs-4968837","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4968837","identity":"rs-4968837","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}