SBS Modified Asphalt Mixture Research Articles

Effects of freeze-thaw cycles on fatigue performance of asphalt mixture and a fatigue-freeze-thaw damage evolution model

To study the effect of freeze-thaw (FT) cycles on the fatigue performance of composite crumb rubber modified asphalt mixtures (CCRMA), a semicircular bending fatigue test based on the digital image correlation technique (DIC) was used to measure the fatigue life (Nf) of CCRMA and SBS modified asphalt mixtures (SBSMA) and the horizontal strain (Exx) of the DIC deformation field under repeated loading. The variation laws of Nf, Exx and the damage factor (D) defined based on Exx were analyzed under FT cycle conditions. In addition, considering the important influence of FT cycles on the Nf and damage evolution characteristics of asphalt mixtures, based on the classical Chaboche damage evolution model, the influence of FT cycle was considered, a fatigue-freeze-thaw damage evolution model that reflects the effects of FT cycling variables and stress levels on asphalt mixtures was constructed. The results indicate that the Exx peak of asphalt mixture shifts forward with increasing FT cycle number. After 20 FT cycles, the Nf of CCRMA decreased by 73.4 %, 62.1 %, and 75.1 %, while that of SBSMA decreased by 76.5 %, 58.6 %, and 74.6 % at stress ratios of 0.2, 0.3, and 0.4, respectively. The fatigue-freeze-thaw damage evolution model predictions were in agreement with experimental results, with the goodness of fit (R2) of all Nf prediction models being greater than 0.9. With the exception of a few outliers, the relative error between the measured and predicted Nf for the two asphalt mixtures was within 15 %. This indicates that the model can effectively predict the Nf and damage evolution laws of asphalt mixtures at different stress levels after an arbitrary number of FT cycles. The related research results provide a theoretical basis for predicting the Nf of new roads in cold regions under FT cycles.

Performance Evaluations of Warm-Mix Reaction-Rejuvenated SBS Modified Asphalt Mixtures Incorporated with Wax-Based Additive

Performance Evaluations of Warm-Mix Reaction-Rejuvenated SBS Modified Asphalt Mixtures Incorporated with Wax-Based Additive

Comparative Performance of Unmodified and SBS-Modified Asphalt Mixtures Made with Blowdown (CarSul) and Calcium Carbonate as Mineral Fillers

Comparative Performance of Unmodified and SBS-Modified Asphalt Mixtures Made with Blowdown (CarSul) and Calcium Carbonate as Mineral Fillers

Evaluation of warm mix effect in laboratory using a self-developed WMA additive Alube

In response to the problems of high mixing temperatures and energy consumption of polymer-modified asphalt mixtures in road construction, a surfactant-based warm mix additive ‘Alube’ was developed. The warm mix SBS-modified asphalt and its mixture were prepared. Their rheological performance and chemical structure were analysed by the rheological and microscopic tests. The active mixing power (P) of asphalt mixtures were examined by the variable speed mixing (VSM) test. The mixing flowability model was then established to evaluate the warm mix effect. The results indicated that the mixing flowability of asphalt mixtures obeyed the linear Bingham visco-plastic model, and the slope and intercept of the flow straight characterised the mixing viscosity and plastic limit. It is evaluated that 0.7% Alube1 and Evotherm reduced the mixing temperature of SBS-modified asphalt mixture by 14°C and 12°C, respectively. Moreover, Alube1 is suitable for a wide range of applications through warm mix asphalt technology.

Investigation on the Preparation and Performances of Epoxy-Modified Asphalt Binder and Its Mixtures.

Epoxy-modified asphalt binder has been widely used in steel deck pavement due to its excellent properties and it is a potential candidate for long life pavements. However, its short reserve time limits its widespread application in pavement engineering. Therefore, this work developed a novel epoxy-modified asphalt binder composed of a laboratory-made curing agent as a solution. Firstly, optimization of preparation temperature of this new material was studied to balance the requirements of enough construction time and the material strength and elongation. The epoxy-modified asphalt binder, prepared at the optimal temperature of 140 °C, had a reserve time exceeding 120 min, whereas the tensile strength and the elongation at failure were 2.22 MPa and 216%, respectively, which satisfied the standard requirements of paving epoxy material well. Secondly, the asphalt mixture property tests demonstrate excellent high-temperature rutting resistance, water stability and low-temperature anti-cracking ability. Additionally, the compatibility and colloidal stability of this epoxy-modified asphalt binder were analyzed in terms of microphase structure. The uniform microphase distribution of this binder showed by the laser confocal microscope observation in both short-term aging case and long-term aging case, indicates the great compatibility between asphalt and epoxy resin during paving process and service life. Furthermore, fatigue tests were conducted to evaluate the long-term durability. The fatigue life of epoxy-modified asphalt mixtures increased by 435%, 427%, 342%, and 276% under the stress ratios of 0.3, 0.4, 0.5, and 0.6, respectively, compared to those of SBS-modified asphalt mixtures. All these results indicate that the new epoxy-modified asphalt material is promising for applications in pavement engineering, especially suitable for long-life road pavement.

Performance evaluation of SBS-modified asphalt mixtures incorporating waste tire rubber and HDPE

Based on the functional complementarity of waste tire rubber (WTR) and waste high-density polyethylene (HDPE) in asphalt, this study presents a novel approach that simultaneously utilizes WTR and HDPE for modification and substitution of styrene-butadiene-styrene (SBS) modified asphalt. Through experiments on three major indicators, the dosage ratios of the three polymers are scientifically designed using the response surface methodology, and four different ratios of SBS-HDPE-WTR are selected to prepare modified asphalt mixtures. Performance evaluations are conducted on various pavement properties, including high-temperature stability, low-temperature crack resistance, water stability, fatigue resistance, and aging resistance, by comparing them to the reference 4% SBS-modified asphalt mixture. The results demonstrate that the addition of WTR significantly improves the elastic properties and fatigue resistance of the mixture, while the addition of HDPE enhances its high-temperature stability and aging resistance. The SBS-HDPE-WTR asphalt mixtures, designed with appropriate ratios, exhibit superior high-temperature stability, low-temperature crack resistance, and fatigue resistance. Therefore, the use of these waste materials in asphalt mixtures offers a sustainable and environmentally friendly solution for the construction industry.

Thermal-Mechanical Coupling Analysis of Permeable Asphalt Pavements

In order to clarify the mechanical response of permeable asphalt pavements under a temperature effect, the mechanical responses of different types of permeable asphalt pavements, which were based on a self-developed drainage SBS-modified asphalt mixture with fiber, were simulated using ANSYS finite element software (APDL 19.2). The influence of temperature and temperature change on the mechanical behavior of the permeable asphalt pavements was studied, and the mechanical responses of the pavements at different driving speeds was analyzed. The results show that the extreme values of surface deflection, compressive strain of the soil foundation top surface, and the shear stress and tensile stress of the upper-layer bottom of the three kinds of pavements under dynamic load were about 10% smaller than those under static loads, and the extreme values under different temperature conditions were 28%~50% larger than the values obtained without different temperature conditions. During the 12 h heating process, the mechanical indexes of the three types of pavements with axle loads were consistent with the change law of temperature, and the peak values of the mechanical indexes under dynamic loads were smaller than those under static loads. In addition, the mechanical indexes of the three types of pavements under dynamic loads had the same law of change with speed under the same conditions, and the values were less than the extreme values under static loads, but the degree of influence was different.

Design and Application of Rich Bottom Layer Mixtures

This study aims to summarize design indexes for rich bottom layer mixtures (RBLMs) and design asphalt mixtures with superior performance to reduce reflective cracks and fatigue cracking resulting from semi-rigid base cracking in the asphalt layer. First, this study synthesizes the research results about RBLMs and introduces the related design indexes. After that, using ABAQUS 6.13, finite element analysis was performed to analyze the change in bottom stress when the base cracked and the interlayer bond weakened. SBS-modified asphalt mixtures (SMMs) and composite-modified asphalt mixtures (CMMs) were subsequently developed as RBLMs utilizing the Marshall test method and applied on a test road. The research findings reveal that design indexes for RBLMs include a volume of air voids (VVs) within the range of 2.0–3.0%, a maximum flexural strain exceeding 3500με, and a dynamic stability surpassing 1000 cycles/mm. Both mixtures satisfy the design requirements, with the CMM demonstrating superior performance and offering promising application prospects. Future research endeavors will concentrate on prolonged monitoring of the test section to authenticate the effectiveness of an RBL in practical road applications.

Evaluation method of modification effect of direct-to-plant SBS modifier on asphalt

To accurately evaluate the modification effect of direct-to-plant styrene–butadiene–styrene block copolymer (SBS) modifier on asphalt, a collection method for direct-to-plant SBS-modified asphalt was proposed in this paper, the qualitative and quantitative evaluation index system was established, and the feasibility of quantitative evaluation based on fluorescence microscopy images and visual inspection of the mixing effect was evaluated, the feasibility of quantitative evaluation indicators was also verified based on the asphalt indicators, rheological properties, and asphalt mixtures's pavement performances. The research results indicate that based on fluorescence microscopy images, by observing the distribution and swelling state of direct-to-plant SBS modifiers can qualitatively evaluate the modification effect of direct-to-plant SBS modifiers on asphalt. Based on the visual inspection of the mixing effect, observe the size and quantity of unmelted particles, determine the melting state of the direct-to-plant SBS modifier, and its modification effect on asphalt can be qualitatively evaluated. For the same direct-to-plant SBS-modified asphalt, the percentage of rotation viscosity between direct-to-plant SBS-modified asphalt and traditional SBS-modified asphalt at 135 ℃ (DAη(135℃)) and discrete coefficient of 135 ℃ rotational viscosity of direct-to-plant SBS-modified asphalt (CVη(135℃)) exhibit a linear relationship with direct-to-plant SBS-modified asphalt's penetration, softening point, and ductility, the smaller the CVη(135℃), the greater the DAη(135℃). The smaller the CVη(135℃) (the larger the DAη(135℃)), the larger the dynamic shear modulus (G*), the smaller the phase angle (δ), and the larger the rutting factor (G*/sinδ) at the same scanning temperature. The relationship between CVη(135℃) (DAη(135℃)) and direct-to-plant SBS modifier on the main technical indicators and rheological performance indicators of asphalt is relatively stable. There is a clear relationship between CVη(135℃) (DAη(135℃)) and the high-temperature stability, low-temperature crack resistance, and water stability of direct-to-plant SBS-modified asphalt mixture, all of which show that as CVη(135℃) decreases (DAη(135℃) increases), the pavement performances improve.

Effect of direct addition of asphalt rubber pellets on mixing, performance and VOCs of asphalt mixtures

Direct injection modifiers revealed vast development potential because of their convenience utilization and no need for professional equipment. However, different characteristics of each direct injection modifier fluctuate significantly on the mixing process and road performance of their modified asphalt mixtures. The purpose of this paper is to evaluate the effectiveness of two novel asphalt rubber pellets (ARP) and asphalt desulfurized rubber pellets (ADRP) in improving the performance of asphalt mixtures. Firstly, this paper used orthogonal experimental design method to determine the priority order of the influencing factors on direct injection modifiers (ARP and ADRP), and further optimized the mixing technology of asphalt mixtures containing direct injection modifiers. Then, using base asphalt, commercial asphalt rubber (AR) and SBS (styrene-butadiene-styrene block copolymer) modified asphalt as control groups, the road performance of five asphalt mixtures was evaluated. Finally, the volatile organic compounds (VOCs) release characteristics of the asphalt mixtures were quantitatively analyzed. The results indicated that the priority order of factors affecting the ARP and ADRP is digestion time > dry mixing time > mixing temperature, and the optimal mixing process parameters are dry mixing for 90 s, mixing temperature of 180 °C, and digestion time of 90 min. Additionally, road performance of ADRP modified asphalt mixtures (ADRP-AM) is superior to that of ARP modified asphalt mixture (ARP-AM), which reaches or even exceeds the road performance of asphalt rubber mixtures (AR-AM) and SBS modified asphalt mixtures (SBS-AM) prepared by wet process. The five asphalt mixtures demonstrate the similar VOCs composition, and the total concentration of VOCs emissions is ARP-AM > AR-AM > ADRP-AM > B-AM > SBS-AM. P-/m-xylene, acetone, benzene, ethylbenzene and substances containing chlorine emerge high concentration for the VOCs composition of the five asphalt mixtures. This research can provide technical support for promoting the widespread application of direct injection asphalt rubber pellets.

Modeling the Dynamic Properties of the Polyurethane Mixture with Dense Gradation Using the 2S2P1D Model

The polyurethane (PU) mixture is a zero-emission and high-performance engineering mixture that could replace traditional asphalt mixtures for pavement paving. This paper investigated the feasibility of using the 2S2P1D model to characterize the linear viscoelastic (LVE) properties of the PU mixture in comparison to the styrene–butadiene–styrene (SBS)-modified asphalt mixture with identical aggregate gradation and binder content. The PU mixture showed higher prediction precision for dynamic modulus and lower prediction precision for phase angle compared to the SBS-modified asphalt mixture. The seven constants of the 2S2P1D model for the PU mixture differed significantly from those of the SBS-modified asphalt mixture. The PU mixture exhibited higher elastic properties and lower creep properties, but the viscous properties represented by the index of η were different from the loss dynamic modulus, which reflected the mixture’s viscous properties. The index η cannot accurately characterize the viscous properties of the PU mixture. The 2S2P1D model exhibited a higher prediction accuracy than the Sigmoidal Christensen Anderson and Marasteanu (SCM) model and could accurately simulate the LVE properties of the PU- and SBS-modified asphalt mixtures. However, the 2S2P1D model should enhance the creep and dashpot elements to provide a more accurate characterization of the properties of the PU mixture.

Study on low temperature crack resistance of warm-mixed recycled SBS modified asphalt mixtures

In view of the cold winter in northern China and the large temperature difference between day and night, the asphalt pavement has been in low temperature service for a long time, in addition to experiencing the aging effect of water and salt erosion, jointly leading to a particularly serious pavement cracking phenomenon. Therefore, a quantity of Reclaimed Asphalt Pavement (RAP) is produced for the repair and renovation of old roads. Faced with the problems of inadequate reuse rate of RAP and high energy consumption of thermal regeneration, it is of great practical significance to explore the technology of warm mix regeneration. In order to study the adaptability of recycled SBS modified asphalt mixtures to low temperature after complex environmental erosion (long-term aging, water freeze-thaw cycle, and salt freeze-thaw cycle), two mixing methods, including hot mixing and warm mixing, were selected, and a Semi-Circular Bending Test was performed. SCB and Digital Image Correlation (DIC) techniques were used to evaluate the low temperature properties of recycled asphalt mixtures by fracture toughness, fracture energy and horizontal strain density damage. Combined with an Atomic Force Microscope (AFM) test, the microscopic analysis of recycled asphalt was carried out to verify the mechanism of low temperature cracking. The results showed that the low temperature cracking resistance of the reclaimed asphalt mixtures with warm mix was slightly worse than that with hot mix. The overall low temperature cracking resistance of the reclaimed SBS modified asphalt mixtures decreased with the increase in RAP content. The low temperature performance of the warm-mixed reclaimed asphalt mixtures deteriorated greatly when the RAP content was 80 %. The influencing factors of environmental conditions on the low temperature cracking resistance of the warm-mixed recycled SBS modified asphalt mixtures were listed as below: long-term aging > salt freeze-thaw cycle > water freeze-thaw cycle. The influence of salt on the stress field of crack tip and the microstructure of recycled asphalt after freeze-thaw was greater than that of water erosion. The changes of the microscopic adhesion were in good agreement with the macroscopic test results, which could be employed as the index evaluating the low temperature crack resistance of the warm-mixed SBS modified asphalt mixtures. The addition of warm mixing agent would play a positive role in the low temperature crack resistance of recycled asphalt mixtures with a RAP content of less than 60 % to a certain extent, so warm-mixed recycled asphalt mixtures were more suitable for the application in northern areas.

Unveiling optimal performance of SBS-modified asphalt mixture: crucial impact of elevated storage temperature and duration of binders

Unveiling optimal performance of SBS-modified asphalt mixture: crucial impact of elevated storage temperature and duration of binders

Experimental investigation on the preparation and surface treatment of biomass fibers for stone mastic asphalt mixtures modification

With the sustainable development of infrastructure construction materials, the use of renewable biomass resources in asphalt mixtures could contribute to better sustainability. The bamboo fibers and corn straw fibers with lengths ranging from 1.5 to 12 mm were produced in the laboratory through the proposed crushing, steaming, and grinding processes. A surface treatment with the phenolic resin copolymer modifier was utilized to reconstruct the micro-surface of biomass fibers. The surface treatment effectively reduced the oil absorption multiplier and mass loss of proposed biomass fibers by about 0.6 and 2 %, respectively. The FI-IR absorption peak and change of micromorphology also validated the effective surface reconstructive. Afterward, the virgin asphalt (70#) mixtures and SBS-modified asphalt mixtures with/without biomass fibers were produced for road performance tests and fatigue resistance tests. The results showed that the proposed biomass fibers contributed to about 20 % to 30 % improvement in the high-temperature performance, while the low-temperature cracking resistance was also obviously increased. In addition, the moisture damage resistance and fatigue life were also improved after the addition of biomass fiber modifier, in which the residual stability and tensile strength ratio were increased by about 9 % and 6 % by comparing that with fibreless mixtures, respectively. By comparing the effect of different types and lengths of fiber modifiers, the long bamboo fiber with surface treatment represented the optimized strengthening efficiency. The enhancement mechanism of proposed biomass fiber modifiers was revealed through the microstructure observation. The feasibility of using proposed biomass fibers with surface treatment for producing high-performance SMA has been verified, which can be utilized in the field application for replacing the lignin fiber modifiers for achieving better sustainability.

Research on Fatigue-Healing Performance of Asphalt Mixture Based on the Semicircular Bending Test.

In order to study the self-healing performance of macroscopic fractures of asphalt mixtures, semicircular bending (SCB) tests were used to test 90# base asphalt mixtures, SBS (Styrene-Butadiene-Styrene) modified asphalt mixtures, and SBS + CR (Chloroprene Rubber) composite modified asphalt mixtures. The F-H-F (the asphalt mixture specimen was fatigued for a certain number of times, then healed under certain conditions, and then fatigued until destroyed) test was carried out, and the fatigue life recovery rate of the fatigue test before and after healing was defined as the healing index (HI). The gray correlation analysis method was used to judge the influence degree of influencing factors on fatigue-healing according to the correlation index. The results show the type of asphalt has the most significant influence on the healing ability of the asphalt mixture. In the case of complete healing, the fatigue-healing performance of the SBS + CR composite modified asphalt mixture was the best, followed by the SBS-modified asphalt mixture, and 90# base asphalt. When the healing temperature is close to the softening point of asphalt, the healing performance of 90# base asphalt is better when the healing temperature is low. When the healing time is longer, the healing performance is better, and there is an optimal healing time. The healing index decreased with the increase in the degree of damage. When the degree of damage is too large, the asphalt mixture will be difficult to heal.

Construction Technology and Pavement Performance of Dry-Mix Polyurethane Modified Asphalt Mixtures: A Case Study

Polyurethane Modified Asphalt Mixture (PUAM) has been confirmed to possess good engineering properties and is a potential replacement material for pavement construction. This study aimed to provide guidance for the promotion and application of PUAM in pavement engineering by exploring the construction technology and verifying the practicality. Dry-mix PUAM (DPAM), wet-mix PUAM (WPAM), and SBS-modified asphalt mixture (SBSAM) were prepared. After systematically investigating the construction process of the three mixtures, their pavement performance was comparatively evaluated. Subsequently, the DPAM was utilized to construct the trial pavement, and the completed pavement was tested and evaluated. Furthermore, the costs of the DPAM and SBSAM were analyzed. The results reveal that the construction technology had a significant effect on the mechanical properties of the mixtures. Compared with SBSAM, the optimum mixing temperature and time of the DPAM and WPAM were reduced. The mixing temperature, mixing time, and hitting number were recommended to be 160 °C, 60 s, and 75 times for the DPAM. Fourier Transform Infrared Spectroscopy tests confirmed that the PU reacted sufficiently in the binder. The DPAM exhibited good overall pavement performance, and its low-temperature cracking and fatigue resistance were significantly better than that of SBSAM. Meanwhile, all the pavement indexes constructed with DPAM met specifications, and the performance and service condition of the test road after the operation will be paid attention to continuously. Additionally, the cost of DPAM was close to that of SBSAM, and the more straightforward construction process and better pavement performance of DPAM could reduce the construction energy consumption and maintenance frequency, which was meaningful for promoting the scale application of DPAM and the sustainable development of transportation infrastructure.

Durability and Rutting Resistance of SBS-Modified Asphalt Mixtures Containing Blowdown as a Sustainable Filler

Durability and Rutting Resistance of SBS-Modified Asphalt Mixtures Containing Blowdown as a Sustainable Filler

Investigation on fatigue characteristics of polyphosphoric acid modified high dosage bio-asphalt mixture under three-dimensional stress state

Polyphosphoric acid modified high dosage bio-asphalt (PMBA) could provide a new direction for saving asphalt resources. The fatigue performance of asphalt mixture is one of the critical factors that should pay more attention in achieving a life cycle cost-effective. This study aims to investigate the strength and fatigue performances of the PMBA mixture. The stress states of mixture tests include indirect tension, direct tension, and unconfined compressive, respectively. The S-N fatigue equations, Desai yield surface, and normalized fatigue equation were determined. At the same loading rate, the strength values of indirect tension and direct tension are close, while the strength of unconfined compressive is much larger than theirs. The S-N fatigue equations parameter obtained based on stress levels vary significantly under different stress states, with unconfined compressive being much more significant than indirect tension and direct tension. The Desai strength yield surface gradually expands outward with the increase of loading velocities. The diffusion rate decreases as the loading velocities increase. According to the Desai yield surface, the new fatigue stress path and stress ratio were defined. The normalized fatigue equation for PMBA mixture under various stress states is Nf=Δ-4.58R2=0.99. The normalized n value of PMBA asphalt mixtures is 4.58, 2.7% lower than that of SBS modified asphalt mixtures. This study is meaningful for applying high dosage bio-asphalt. The application of PMBA also provides new ideas for low carbon and environmental protection in road engineering.

Mechanical damage characteristics of CR/PPA composite modified asphalt pavement under multi-factor coupling effect in the seasonally frozen region

Asphalt pavements are inevitably affected by coupled effects of dry-wet/freeze-thaw cycles, UV radiation, temperature, and loading during service, resulting in degradation of their road performance and reduced service life. Therefore, this study used crumb rubber (CR) and polyphosphoric acid (PPA) as modifiers to prepare CR/PPA composite modified asphalt mixtures for testing. To investigate the mechanical properties of the composite modified asphalt mixtures under the action of multi-factor coupling. Meanwhile, the performance analysis of matrix asphalt and SBS modified asphalt mixtures were carried out as a comparison. Density and water penetration tests, splitting tests, beam bending tests, and four-point bending fatigue tests reveal the evolution of asphalt mixture road performance. Finally, regression fitting was performed on the test data to establish the mechanical damage model of each type of asphalt mixture. The results show that with the increase of wet-dry/freeze-thaw cycles and the increase of UV radiation time, the void ratio and water permeability coefficient increase and the splitting strength, bending and tensile strain, and fatigue life decrease for all types of asphalt mixtures. When the number of wet-dry/freeze-thaw cycles reached 8, the mechanical properties of the asphalt mixture decreased significantly, while the changes leveled off after the number of cycles reached 15. When the UV radiation time is less than 4 months, the mechanical properties of the asphalt mixture decay more slowly. However, with a further increase in radiation time, the mechanical properties decay rapidly. The water-saturated specimens have a more significant effect on the mechanical damage of each type of asphalt mixture. Compared with the other two mixtures, the composite modified asphalt mixtures have superior mechanical properties and fatigue life. The mixture performance damage model based on the least squares Levenberg-Marquardt method (L-M method) was able to simulate the experimental data well, with a minimum correlation coefficient R2 of 0.9285. In summary, the road performance of all types of asphalt mixtures under the coupling of multiple factors has deteriorated, while the composite modified asphalt mixtures have better anti-damage characteristics, with good prospects for promotion.

Study on the Dynamic Performance of PU and SBS-Modified Asphalt Mixtures with Dense Gradation

A polyurethane (PU) mixture with excellent strength is regarded as an alternative to a modified asphalt mixture, but characteristic analysis on them is lacking. In this paper, the dynamic modulus of PU- and SBS-modified asphalt mixtures with the same gradation, aggregate type, and binder content was investigated and compared in terms of dynamic and viscoelastic properties. Compared with the SBS-modified asphalt mixture, the PU mixture with an extremely high dynamic modulus and reduced phase angle at high temperatures had lower temperature sensitivity, which allowed it to resist high-temperature deformation. While the phase angle did not show a statistically significant correlation, the dynamic modulus between the two mixtures did. The dynamic modulus and phase angle values of the PU mixture showed relatively small deviations and could be fitted to produce acceptable master curves, which exhibited obvious differences compared to those of the SBS-modified asphalt mixture. The PU mixture exhibited elastic properties during the test temperature range and, since its thermal rheological property is much smaller than that of the SBS-modified asphalt mixture, it is closer to viscoelastic material. This study provides an understanding of the PU mixture’s dynamic and viscoelastic properties, as well as material information for pavement design and performance prediction with PU mixture layers.