Performance Of Asphalt Binder Research Articles

Study on the performances of epoxy asphalt binders influenced by the dosage of epoxy resin and its application to steel bridge deck pavement

The concentration of epoxy resin can outstandingly affect the performance of hot-mixed epoxy asphalt binders. A standard measuring procedure of tensile performance for plastics is applied to investigate epoxy asphalt binders influenced by different dosages of epoxy. The rheological performances and microscope structure evolution process influenced by hot mixed epoxy dosage are investigated by dynamic shear rheometer and laser scanning confocal microscopy respectively. The consequences manifest that the flexibility and anti-rutting ability of epoxy asphalt binders is raised accompanied by raising the dosage of epoxy resin are founded by long time of creep, creep and recovery. Dynamic shear rheometer temperature scans showed that epoxy asphalt binders exhibited excellent thermal stability within the scope of -20 oC and 120oC, when the amount of epoxy resin is no less than 40%. It was observed by laser scanning confocal microscopy that the three-dimensional crosslinked network structure was gradually shaped when the epoxy resin concentration was no less than 40%. These experimental results demonstrated that the excellent performances of epoxy asphalt binders are obtained when the concentration of epoxy resin is no less than 40%. From the viewpoint of epoxy asphalt mixtures, the optimal mixture performances are acquired, when the concentration of epoxy resin is no less than 40%. Finally, when the concentration of epoxy resin is 40%, the excellent cost-performance of epoxy asphalt is obtained, which can be used in steel bridge deck pavement.

Influence of Biomass-Modified Asphalt Binder on Rutting Resistance

Biomasses are environmentally friendly additives that lower pollution in pavement engineering because of their biodegradability. On the other hand, to build a safe, long-lasting pavement, rutting prevention is crucial. This study provides a comprehensive review of the efficacy of biomass as recyclable materials in reducing rutting and enhancing characteristics of asphalt mixtures. According to findings, the hydrocarbon polymer properties of lignin and biomass ash improve asphalt binder consistency, hardness, and function at high temperatures. The results showed that biochar, due to its solid shape, enhances the stiffness and viscosity of the mixtures. The high-temperature performance of asphalt binder is improved by bioshell waste, which increases rutting parameters. Thus, biomass like ash, lignin, and biochar can increase asphalt binder rheology and rutting resistance due to chemical forces such as Van der Waals and hydrogen ions. The macroscopic and microscopic investigation also shows higher interaction and better adhesion in bioasphalt. However, asphalt binders containing bio-oil exhibited no unique behaviors due to their lubricant impact. Based on the estimation of the life cycle assessment (LCA), it was determined that biomass utilization has the potential to decrease the cost and CO2 emissions of pavement engineering by as much as 10% and more than three times, respectively. An examination of recyclability revealed that biomass utilization can decrease the requirement for additional stabilizers by as much as 20%.

Investigation of Polymer-Asphalt Compatibility Using Molecular Dynamics Simulation.

Polymer modification is a promising approach to enhancing the performance of asphalt binders. However, a major issue plaguing polymer mixing with asphalt is the phase separation of these two components post-mixing. In the field of polymer science, the Flory-Huggins theory has been long established as the way to describe the conditions under which a mixture is stable or unstable. This Flory-Huggins interaction parameter χ and the molecular weights of the components are required under this theory. This work uses molecular dynamics simulations to calculate χ between various polymers found in waste plastics and asphalt. The compatibility of these polymers with the asphalt binder is discussed as a function of binder composition, molecular weight, and temperature. Four common polymers (polyethylene, polystyrene, polypropylene, and polybutadiene) were tested. While none of the polymers showed good compatibility with asphalt, PE was the most compatible. Stable compatibilization of plastics with asphalt will require additives or chemical modification of the plastic.

Assessment and mechanism of antioxidant activity of phenols as asphalt antioxidants

ABSTRACT The interest in the antioxidant properties of phenolic compounds in asphalt has grown significantly. This study primarily focuses on the comprehensive assessment and elucidation of the antioxidant activity mechanisms of various phenolic compounds as asphalt antioxidants. The suitability of different antioxidant indices for evaluating the effectiveness of phenolic anti-aging agents in base and SBS modified asphalt is assessed by experimental outcomes. Through this analysis, the anti-aging mechanism of phenolic antioxidants in asphalt is unveiled. Phenolic antioxidants were observed to diminish the G* value of aged asphalt, elevate the δ values of aged asphalt binder, augment the non-recoverable creep compliance of aged asphalt binder, decrease the percent recovery of aged asphalt binder, enhance the fatigue performance of aged asphalt binder, and lower the Ic = o and Ic = c of aged asphalt binder. This indicates that phenolic antioxidants improve the aging and fatigue resistance of asphalt binders, with antioxidant activities in the following order: p-Coumaric acid < resveratrol < tea polyphenol. Moreover, incorporating phenolic antioxidants into SBS modified asphalt not only restrains asphalt oxidation but also mitigates SBS degradation.

Phase Separation Study on the Storage of Technically Specification Natural Rubber Modified Bitumen

Overloading and climate change are often problems in pavement structures. For this reason, hard asphalt binders have high softening points, are elastic, and have good adhesion, which is needed to improve pavement performance. Asphalt binder performance can be enhanced by adding additives such as natural rubber or natural-rubber-modified asphalt. However, natural-rubber-modified asphalt shows poor storage stability problems. This is due to differences in density and viscosity between the constituent components of natural-rubber-modified asphalt. This study examines the phase separation mechanism in technically specified natural rubber (TSNR) modified asphalt. Prediction of the optimum storage length of modified asphalt before phase separation occurs, using a combined incompressible Navier–Stokes and phase field model and carried out with COMSOL Multiphysics software version 5.5. Experimental validation was conducted at TSNR levels of 8, 10, and 12% at 160 °C for 48 h, with and without sulfur. The simulation showed that the asphalt modified with TSNR experienced phase separation after 12 h of storage at 160 °C under conditions without stirring. This aligns with the experimental results, which showed phase separation at 160 °C after 48 h. Adding sulfur additives did not have much effect on improving storage stability. The combined incompressible Navier–Stokes and phase field model accurately describes the phase separation in TSNR-modified asphalt. The results of this research recommend that the industry store natural-rubber-modified asphalt in a constantly stirred condition to prevent phase separation of modified asphalt. In addition, the results of this research help the industry predict or increase the homogeneity of polymer-modified asphalt production and save time and costs.

Enhancing Sustainability and Performance of Asphalt Binders: Unlocking the Potential of Unsegregated Residual Vegetable Oil

Enhancing Sustainability and Performance of Asphalt Binders: Unlocking the Potential of Unsegregated Residual Vegetable Oil

Properties of waste vegetable oil recycled asphalt-binder: a molecular simulation study

ABSTRACT The aging of asphalt-binder during long-term use is an important reason for the decline in road performance of asphalt mixtures. In this study, waste vegetable oil (fried for 1-2h) was investigated as a rejuvenator of asphalt-binder. The optimisation effect of waste vegetable oil on the performance of asphalt-binder with different aging degrees (RTFOT, PAV15/20/48h) was evaluated by testing their conventional physical properties, high-temperature properties, and low-temperature properties. The molecular dynamics method was used to construct models, and the diffusion properties, solubility properties, adsorption energy, and asphaltene aggregation were calculated. The influences of linoelaidic acid and oleic acid molecules on aged asphalt-binder molecules were evaluated. The changes in the functional groups of the aged asphalt-binder after the addition of waste vegetable oil were analyzed by infrared spectrometry, and the changes in the microstructure of the aged asphalt-binder surface were observed by scanning electron microscopy. The results revealed that waste vegetable oil could regenerate aged asphalt-binder and significantly improve their physical and high-/low-temperature properties. Waste vegetable oil molecules are compatible with aged asphalt-binder molecules, improve their diffusion behaviour, enhance their adsorption capacity, and slightly reduce the aggregation of asphaltenes. Overall, waste vegetable oil shows great potential for the regeneration of aged asphalt-binder.

Towards a high-performance asphalt concrete for extreme climatic conditions using asphaltenes and polyethylene terephthalate fibres

Asphalt pavement experiences various deteriorations in different weather conditions due to the viscoelastic nature of asphalt binder. This study aims to develop a high-performance asphalt concrete (HPAC) for extreme temperature conditions by incorporating waste polyethylene terephthalate (PET) fibres and asphaltenes, a by-product from Alberta oil sands. First, performance of asphalt binder modified with asphaltenes is evaluated according to the Superpave performance grading (PG) system. Next, to improve low-temperature properties, HPAC mixtures modified with PET fibre at percentages of 0.05–0.30% are tested for compactibility to reflect field construction considerations. Then, performance tests including dynamic modulus; indirect tensile strength test at low temperatures; and Hamburg wheel-track at high temperature are conducted for an effective evaluation of the unmodified and modified mixtures that are prepared using a combination of the dry and wet mix methods. Results of binder PG tests reveal that with 12% asphaltenes, the modified binder is suitable for HPAC applications. The mixes with and without PET fibres exhibit similar compactibility and meet air void requirements of a maximum 6%, and incorporating PET fibres increases stiffness by up to 3.3%. Compared with the unmodified mixes, an optimum dosage of 0.15% PET fibre increases fracture energy by up to 27% at −10 °C and enhances tensile strength by up to 18% at 0 °C. The mixture with the optimum dosage also exhibits excellent rut resistance at 60 °C showing no signs of moisture damage sensitivity. As a result, it boasts a remarkable rutting resistance index that is five times higher than that of the control unmodified mix.

Effect of microwave pretreatment on characteristics of asphalt binders modified with scrap non-tire automotive rubber and waste derived pyrolytic oils after prolonged thermal storage

The use of waste automotive rubber and pyrolytic products has recently gained interest in asphalt binder modification, and it also presents an appealing solution towards waste re-utilization and sustainable asphalt binder modification. Further, composite modification of asphalt binders is now often attempted to achieve a wider range of benefits in the asphalt binder performance through the modifiers. For the petroleum crude-based asphalt binders after their modification with different additives, viz. polymers, rubbers, and oils, the phase separation behavior, usually assessed in terms of storage stability, plays a very important and crucial role in its long-term performance. A modified asphalt binder must possess adequate storage stability to assure homogeneity during storage and hauling at elevated temperatures to achieve the desired performance after construction. The present study firstly evaluated the long-term phase separation behavior/storage stability of asphalt binders modified with waste non-tire rubber granules (ethylene-propylene-diene monomer (EPDM) type) alone and then for composite rubberized asphalt binders formulated with EPDM rubber along with tire pyrolytic oil (TPO) and plastic pyrolytic oil (PPO) after microwave pretreatment. To assess the standard and the long-term phase separation behavior in terms of storage stability, formulated rubberized asphalt binders were subjected to thermal storage at two different scenarios: (a) for 2 and 4 days at163 °C, and (b) for 2, 4, 7, 10, and 14 days at 135 °C. The phase separation behavior and performance of rubberized asphalts post long-term storage were evaluated in terms of chemo-rheological, microstructural, and rubber dissolution tests. A total of 28 asphalt binders with variable modification and thermal storage periods were characterized and evaluated. Both storage temperature and duration were found to play a critical role in dictating the storage stability and chemo-rheological performance of the rubberized asphalts, and the prolonged storage stability of rubberized binders correlates well with their rutting and fatigue performance. The pretreatment of rubber granules with pyrolysis oils using microwave irradiation facilitated the achievement of a composite modified asphalt binder with good storage stability and rheological performance.

Enhancing Asphalt Performance and Its Long-Term Sustainability with Nano Calcium Carbonate and Nano Hydrated Lime

Nanomaterials enhance the performance of both asphalt binders and asphalt mixtures. They also improve asphalt durability, which reduces resource consumption and environmental impact in the long term associated with the production and transportation of asphalt materials. Thus, this paper studies the effectiveness of Nano Calcium Carbonate (Nano CaCO3) and Nano Hydrated Lime (NHL) as modifiers and examines their impact on ranges from 0% to 10% through comprehensive laboratory tests. Softening point, penetration, storage stability, viscosity, and mass loss due to short-term aging using the Rolling Thin Film Oven Test (RTFO) were performed on asphalt binders. Results indicated a significant improvement in binder stiffness, particularly at 4% Nano CaCO3 and 6% NHL content by weight. Dynamic Shear Rheometer (DSR) tests further revealed substantial improvements in rutting resistance, with NHL exhibiting superior high-temperature stability and a notable increase in the rutting factor. Marshall stability tests on asphalt concrete (AC) mixtures showed a 22.3% increase in stability with 6% NHL by weight, surpassing the 20.2% improvement observed with Nano CaCO3 and indicating enhanced load-bearing capacity. The resilient modulus of the mixtures consistently increased with the addition of NHL, suggesting improved durability in rutting. Moisture susceptibility tests revealed that NHL significantly enhances moisture resistance, exceeding the 80% TSR benchmark at just 2% content by weight and reaching an impressive 94.6% at 10% content by weight. In contrast, Nano CaCO3 demonstrated a more gradual improvement, achieving an 88.2% TSR at 10% content. Furthermore, permanent deformation analysis indicated a 68.64% improvement in rutting resistance with 10% NHL content by weight, exceeding Nano CaCO3’s improvement rate. Optimal fatigue resistance was achieved at 4% for Nano CaCO3 and 6% for NHL by weight, with respective CT index improvements of 30% and 35.4%, showing NHL’s consistent benefits across various nanomaterial contents. Overall, the study suggests that both Nano CaCO3 and NHL positively impact asphalt performance, with NHL offering more pronounced benefits across a range of properties. These findings provide valuable insights for pavement engineers and underscore NHL’s potential as an effective additive in asphalt mixture design. Real-world applications and validations are essential for a comprehensive understanding of these nanomaterials in practical pavement engineering scenarios.

Effects of Anhydrous Calcium Sulfate Whisker and Waste Engine Oil on Performance of Asphalt Binder and Its Mixture

Effects of Anhydrous Calcium Sulfate Whisker and Waste Engine Oil on Performance of Asphalt Binder and Its Mixture

A molecular dynamics simulation study on the recovery performance of aged asphalt binder by waste vegetable oil rejuvenators

This study employed molecular dynamics to simulate the recovery performance of a waste vegetable oil rejuvenator on aged asphalt binder. The model's accuracy was verified through density and glass transition temperature (Tg) calculations. The Radial Distribution Function (RDF) was utilized to assess the aggregation state of different asphalt binder components. The impact of the waste vegetable oil rejuvenator on asphalt binder microstructure was evaluated using cohesive energy density (CED), relative concentration, mean square displacement (MSD), radius of gyration (Rg), and free volume amount. Changes in functional groups of the aged and recycled asphalt binder samples were analyzed using Fourier transform infrared spectroscopy (FT-IR). Results indicate that the rejuvenator significantly influences the dispersion of SARA components. Improved compatibility between aged and virgin asphalt binders is achieved through increased activity of asphaltenes and resins. The incorporation of rejuvenators into asphalt binder mildly counters the aggregation of asphalt binder molecular structure, mitigates the negative effects of aging, and restores asphalt binder structure. The rejuvenator, enriched with polar groups as per FT-IR tests, increases the proportion of polar groups in the recycled asphalt binder. The recycled asphalt binder exhibits a higher proportion of polar molecules, and the rejuvenator reacts with the polar molecules in the asphalt binder at high temperatures.

Effect of Compounded Aluminum Hydroxide Flame Retardants on the Flammability and Smoke Suppression Performance of Asphalt Binders.

Compounded aluminum hydroxide (ATH) flame retardants have been widely used for their low cost and environmentally friendly characteristics. However, previous research lacks a systematic and comprehensive comparison. In addition, the combustion characteristics and phase characterization of asphalt binders are not taken into account either. In this work, flame retardants, for instance, APP, Sb2O3, ZB, and LDHs, were compounded with ATH. The flame retardant behavior, together with the smoke suppression behavior, of asphalt binders with compounded flame retardants was determined by LOI and CCT. Furthermore, mechanisms on flame retardants were investigated. It was found that ATH compounded with ZB significantly reduced the heat smoke release and suppressed the formation of toxic volatiles during asphalt combustion. This was because ATH/ZB facilitated the formation of polyaromatic structures and improved the resistance of the char layer. ATH compounded with APP showed an antagonistic effect in the limiting oxygen test because the reaction between ATH and APP inhibited and delayed the decomposition of ATH during asphalt combustion with more aluminum phosphate presenting relatively poor barrier properties produced.

Motion Characteristics of Interfacial Water and Its Effect on the Performance of Cold-Mixed Epoxy Asphalt Binder: A Molecular Dynamics Study

Motion Characteristics of Interfacial Water and Its Effect on the Performance of Cold-Mixed Epoxy Asphalt Binder: A Molecular Dynamics Study

Performance evaluation of rapeseed oil-based derivatives modified hard asphalt binders: Towards greener and more sustainable asphalt additives

Hard asphalt binder is regarded as a favorable option in comparison to polymer-modified asphalt for rutting due to the benefits of cost-effectiveness and extreme stiffness behavior. However, its inherent poor ability to withstand fatigue damage and thermal cracking restricts its applications as a pavement material. This study aimed at enhancing the low-temperature and fatigue performance of hard asphalt binders with newly-developed rapeseed oil (RO)-based derivatives. Two rapeseed oil -based derivatives of epoxidized rapeseed oil (ERO) and acrylated epoxidized rapeseed oil (AERO) were laboratory synthesized through oxidation and ring-opening grafting reactions, respectively. Fourier transform infrared spectroscopy (FTIR) and Hydrogen nuclear magnetic resonance (1were conducted to confirm the successful synthesis of derivatives. Mass loss, aging index, performance grading, temperature-frequency sweep, linear amplitude sweep and bending beam rheometer test were employed to assess the modified effects of rapeseed oil-based derivatives on two types of hard asphalt binders. To further explore the differences between RO and derivatives, the properties of modified hard asphalt binders using two derivatives were compared against the performance of RO-modified hard asphalt binders. With the additional RO, ERO, and AERO, the modified hard asphalt binders had significantly improved the resistance to thermal cracking and fatigue damage at low and intermediate temperatures, respectively. RO was found to have the most positive effect on the stress relaxation and the most adverse effect on the stiffness of hard asphalt binders. While, ERO- and AERO-modified hard asphalt binders had shown better antioxidative and anti-aging performance than that of RO-modified hard asphalt binders. Additionally, AERO-modified hard asphalt binders were noticed to have improved the elasticity of hard asphalt binders owing to the formation of a polymer elastic network. According to the study, two rapeseed oil-based derivatives had shown great potential as green and sustainable asphalt modifiers on the improvement of thermal and fatigue cracking resistance with the minimal adverse effect on anti-rutting performance of the hard asphalt binders. The test results revealed that the rapeseed oil-based derivatives modified hard asphalt binders could be employed in various pavement applications with great economic and sustainable benefits.

Exploring the low-temperature performance of MPP-modified asphalt binders and mixtures using wet method

Thermal cracking significantly impacts the structural integrity of flexible pavements, particularly in colder regions like Canada. Limited studies investigated the impact of plastic modification of asphalt binders and mixtures using the wet method on the low-temperature performance of asphalt materials. The plastic material utilized in this project is multilayer plastic packaging (MPP). This study aims to determine whether MPP can be integrated to enhance the performance of the MPP-modified binder and MPP-modified mixtures, especially considering that MPP accounts for just over 40% of total plastic usage, making it the largest end-use market segment. This research evaluates the impact on rheological and mechanical behaviour when introducing MPP additives to conventional hot mix asphalt. This study used the wet method to test MPP-modified asphalt materials at 2%, 4%, and 8% (by weight of the asphalt binder). Test results demonstrate that the MPP modification percentage should ideally not exceed 2% as blends with 4% MPP or higher exhibited lower performance at low temperatures. The use of a softer binder as a base binder would help increase the MPP modification rates, but this hypothesis needs to be validated experimentally.

Reactive Extrusion of Waste Plastics with Compatibilizer and Lightly Pyrolyzed Crumb Rubber for Asphalt Modification

Modifying asphalt is a potentially high-value application for reusing waste plastics because of the high-volume usage of asphalt in highway construction. However, simply blending hot plastics and asphalt encounters difficulties related to the poor solubility of polymers, which limits the formation of a swollen network with asphalt molecules. The polymer phases also tend to coalesce and separate from asphalt during high-temperature storage in static conditions. The present study developed an innovative process to stabilize waste plastics in asphalt and improve binder storage stability by using lightly pyrolyzed crumb rubber together with a chemical compatibilizer. Both polymers were extruded to produce a thermoplastic elastomer (TPE) for asphalt modification. The mechanical performance and chemical reactions of TPEs were characterized via tension test and Fourier transform infrared spectroscopy. The storage stability and rheological properties of modified binder blends were evaluated through laboratory asphalt stability test and dynamic shear rheometer test. Polymer phases and network structures were characterized through optical microscopy. It was found that the pyrolyzed and reactive extrusion process improved the rubber solubility and polymer interaction, and therefore the storage stability of modified binder blends. The co-existence of rigid plastic and soft rubbery regimes in an entangled network provided a promising pathway to improve the mechanical performance of asphalt binders in both high- and low-temperature domains.

Effect of polyisobutylene on low-temperature thermoreversible aging properties in asphalt binders

In order to study the influence of polyisobutylene (PIB) on pavement performance of asphalt binders, two asphalt binders with large differences in wax content and the similar performance grades were selected as the base asphalt binders, and three kinds of waxes and PIB were selected as additives. Extended bending beam rheometer (Ex-BBR) test, double-edge-notched tension (DENT) test, multiple stress creep recovery (MSCR) test and rotational viscosity test were used to study the effect of PIB on the low, medium and high temperature properties of asphalt binders, respectively. The phase transition pattern of PIB when interacting with waxes was analyzed by variable temperature polarizing microscope (VT-PLM). The results show that PIB can be miscible with waxes and reduce the melting point of waxes by about 20∼60%. PIB can improve the low-temperature performance (reducing creep stiffness), medium-temperature performance (increasing toughness and fracture resistance), high-temperature performance (improving high-temperature deformation resistance and deformation recovery ability) and workability (reducing mixing and compaction temperature) of asphalt binders (including high-wax and wax-based warm-mixed asphalt binders). It is worth noting that PIB will aggravate the thermoreversible aging (the results of P-value analysis showed that PIB had a significant effect on the grade loss (GL) of asphalt binders), which will affect the low-temperature performance of asphalt binders during the isothermal low-temperature storage, resulting in premature damage to the pavement.

Evaluating the Ageing Sensitivity of the Asphalt Binder via Distinct Ageing Methods

Asphalt binder is a crucial component of asphalt pavements that undergoes ageing over time, which can result in the reduced performance and deterioration of pavements. Consequently, artificial ageing methods play a significant role in providing valuable insights into the ageing behaviour and long-term performance of asphalt binders. However, a consensus on the most effective method for simulating ageing behaviour remains elusive, leading to disparities in the outcomes across different research studies. To address this issue, the study utilises two thermo-oxidative ageing approaches, one focusing on the binder itself and another on the loose asphalt mixture. The study investigates the effect of these ageing methods on the behaviour of asphalt binder using physical, rheological, and chemical characterisation. For the binder ageing method, a rolling thin film oven (RTFO) and a pressure ageing vessel (PAV) were utilised, whereas the loose asphalt mixture ageing was performed in an oven at 95 °C for various durations. The results indicated that the ageing trend differed between the two oxidative ageing approaches as the ageing duration increased. However, by employing an ageing sensitivity index, comparable rheological properties were observed between the binders aged using the PAV for 20 h and the loose asphalt mixture for 5 days. The Fourier Transform Infrared (FTIR) spectroscopy analysis revealed that the ageing methods influenced the functional groups associated with ageing in distinct ways, even though they exhibited similar rheological behaviour. Overall, this study provides a comprehensive understanding of different thermo-oxidative ageing approaches, their correlation, and their relevance to the studied field-aged binders.

Mechanism of physical hardening on the fracture characteristics of polymer-modified asphalt binder

This article aims to reveal the physical hardening mechanism of polymer-modified asphalt binder (PMA) and accurately assess its impact on the low-temperature fracture properties of asphalt binders. Base asphalt binder (BA), styrene–butadiene–styrene modified asphalt binder (SBSMA), and crumb rubber modified asphalt binder (CRMA) were used as the research objects. Molecular dynamics (MD) simulation and differential scanning calorimetry (DSC) test were used to investigate the physical hardening mechanism of PMA at the microscopic level. The fracture characteristics of PMA under physical hardening were analyzed based on the single-edge notched beam (SENB) test. The results show that under prolonged cold service conditions, the asphalt molecular mobility is weakened, the non-bond energy and the free volume are reduced, and the molecules undergo aggregation state transformation, leading to the physical hardening of asphalt materials. In the process of physical hardening of asphalt molecules in the micro-Brownian motion of the main active force from the aromatic and saturate fractions. Considering the effect of physical hardening, it is recommended that the method used to test the low temperature properties of asphalt binders should ensure a constant temperature for at least 24 h. The crack tolerance (Ct) is recommended as the evaluation index of low-temperature cracking resistance of PMA in cold regions. The Ct of BA, SBSMA, and CRMA are reduced by 52.88 %, 12.04 %, and 35.24 %, respectively, after 24 h of constant low temperature. This indicating that the polymer modifiers can improve the fluidity of asphalt molecules, inhibit molecular aggregation, and reduce the effect of physical hardening on asphalt binders. Thermo-oxidative aging can aggravate the physical hardening phenomenon of asphalt binder, and the higher the degree of thermo-oxidative aging, the more severe the physical hardening of asphalt binder. The related research results provide the theoretical basis and technical support for the accurate design and development of the low-temperature performance of asphalt binders for roads in cold regions.