Asphalt Materials Research Articles

A Study on the Effectiveness of Climate Adaptation Materials for Urban Heat Islands using Digital Twin and Computational Fluid Dynamics

This study analyzed the impact of climate adaptation materials on the mitigation of urban heat islands (UHI) using digital twin visualization and computational fluid dynamics (CFD) technology. The effects of UHI due to increased impervious surfaces have become more pronounced, and climate-adaptation materials are gaining attention as potential solutions. In this study, the impact of climate adaptation materials on UHI mitigation was analyzed using the CFD program STAR-CCM+ based on the finite volume method (FVM). The selected research site was Byeoryang-dong, Gwacheon City, and four simulation scenarios were created based on the emissivity values of the asphalt and concrete materials. The results showed that application of climate adaptation materials decreased the surface and aboveground (1.5 m) temperatures by 6.3 and 0.8 °C, respectively. This study suggests that climate adaptation materials can significantly mitigate UHI.

Preliminary Study on Multi-Scale Modeling of Asphalt Materials: Evaluation of Material Behavior through an RVE-Based Approach

This study employs a microstructure-based finite element modeling approach to understand the mechanical behavior of asphalt mixtures across different length scales. Specifically, this work aims to develop a multi-scale modeling approach employing representative volume elements (RVEs) of optimal size; this is a key issue in asphalt modeling for high-fidelity fracture modeling of heterogeneous asphalt mixtures. To determine the optimal RVE size, a convergence analysis of homogenized elastic properties is conducted using two types of RVEs, one made with polydisperse spherical inclusions, and another made with polydisperse truncated cylindrical inclusions, each aligned with the American Association of State Highway and Transportation Official’s maximum density gradation curve for a 12.5 mm Nominal Maximum Aggregate Size (NMAS). The minimum RVE lengths for this NMAS were found to be in the range of 32–34 mm. After the optimal RVE size for each inclusion shape is obtained, computational models of heterogeneous Indirect Tensile Asphalt Cracking Test samples are then generated. These models include the components of viscoelastic mastic, linear elastic aggregates, and cohesive zone modeling to simulate the rate-dependent failure evolution from micro- to macro-cracking. Examination of load-displacement responses at multiple loading rates shows that both heterogeneous models replicate experimentally measured data satisfactorily. Through micro- and macro-level analyses, this study enhances our understanding of the composition-performance relationships in asphalt pavement materials. The procedure proposed in this study allows us to identify the optimal RVE sizes that preserve computational efficiency without significantly compromising their ability to capture the asphalt material behavior under specific operational conditions.

Preprocessing and postprocessing analysis for hot-mix asphalt dynamic modulus experimental data

Dynamic modulus (|E*|) measurements of hot-mix asphalt (HMA) mixtures are critical for understanding material behavior but present significant challenges due to the complex testing procedures and precision required. While substantial efforts have focused on developing predictive models for |E*|, the critical role of experimental data preprocessing has been largely overlooked in the existing literature. This study addresses this gap by proposing a novel, comprehensive framework for both preprocessing and post-processing of dynamic modulus data. Leveraging the well-established ASU |E*| database and the NCHRP 1–40D Witczak prediction model as benchmarks, we introduce advanced empirical techniques, including probability distribution analysis, scatter and box plots, correlation coefficients, and mutual information metrics, to refine data quality and enhance the interpretability of predictive models. Our approach reveals new insights into the interaction of various input factors and |E*| values, leading to improved model robustness and reliability. The post-processing techniques further substantiate the predictive power of the Witczak model, yielding significant enhancements in accuracy and reliability. This research pioneers a standardized data preparation methodology that sets a new precedent in asphalt material engineering, offering a robust foundation for future |E*| modeling and analysis.

Study on the composition and properties of EME-SBS-Nano ZnO high modulus asphalt material

The objective of this research is to address the rut problems in asphalt pavements and to resist the permanent plastic deformation with the increasing heavy traffic loads. In this paper, a new type materials of high modulus asphalt was developed by incorporating styrene–butadiene–styrene (SBS) and zinc oxide nanoparticles (nano ZnO) with an (EME)-type high modulus modifier, guided by the synergistic effects and the preparation methods of High-speed shear. The basic road performance, mechanical response and thermal stability of the new high modulus asphalt materials were analysed through basic physical indicator tests, dynamic shear rheometer tests, thermogravimetric analysis (TGA), the time–temperature superposition principle, the Refutas model, and the Christensen-Andersen-Marasteanu model. The optimal results demonstrate that the optimal blend ratio of the developed asphalt is 12% EME/8% SBS/1.5% ZnO. Under this composition, the road performance indicator values of softening point, penetration and ductility of the modified asphalt met the standard requirements. The dynamic shear rheometer tests demonstrates that the inclusion of SBS and nano ZnO considerably enhanced the shear resistance and recovery deformation capacity of EME, effectively improving the high-temperature deformation resistance of asphalt. Furthermore,the Refutas and the Christensen-Andersen-Marasteanu model fitting results showed that adding SBS and nano ZnO considerably improved the temperature sensitivity of the EME types high modulus modified asphalt and exhibiting low frequency sensitivity. Compared to PR Module-type high modulus modifier(PRM),TGA reveals that the maximum thermal weight loss of EME-SBS-ZnO decreased by 3.5441%, indicating better thermal stability and the major character of SBS,EME and asphalt is physical reaction. Moreover, EME-nano ZnO-SBS high modulus asphalt at 64 °C shows Jnr-diff = 9.5% and passes the "E" extreme traffic grade. Additionally, its cost is 4.67% lower than that of the PRM high modulus modified asphalt, presenting considerable economic benefits.

The effect of ultraviolet radiation on asphalt functional group through FTIR and EW method

Ultraviolet (UV) ageing is an important factor affecting the service performance of asphalt pavement. However, at present, the group transformation of asphalt under ultraviolet radiation is still need to be studied. The ageing mechanism of asphalt could be better revealed through studying the functional groups of asphalt. In this study, asphalt were aged by three kinds of ultraviolet light. The changes of characteristic functional groups of asphalt before and after ultraviolet ageing were analyzed by infrared spectroscopy. Finally, the entropy weight method was used to calculate the count of inter conversion. The results showed that the carbonyl index of asphalt increased after ultraviolet ageing, while the methylene index, aromatic index, aliphatic index, and sulfoxide index decreased. After the asphalt is aged by ultraviolet, the C-C, C-H and C=C bonds in the asphalt material will be converted to C=O, and S=O will be converted to SO2. The results could be used to simulate asphalt molecules in order to better understand the performance and properties of asphalt.

Distribution pattern and assembly mechanism of microbial community to cause biological aging of asphalt materials in forest road domain

The biological aging of asphalt due to microorganism decomposition causes such distresses as loosening and spalling on asphalt pavement in forest region, which deteriorates the durability of asphalt pavement. To study the distribution regularities of microbial communities in forest road domain and reveal the assembly mechanisms of microbial communities, 16S rRNA full-length sequencing was utilized to analyze the collected samples from three forest areas. Results show that when compared with those in roadside slope, the evenness and diversity of microbial community in asphalt pavement are decreased, but the richness of microbial community is significantly increased. Mycolicibacterium is screened for a biomarker in asphalt pavement. Additionally, the increase in the relative abundances of Bacteroidetes and Proteobacteria, which are the dominant bacteria in asphalt pavement, reshapes the co-occurrence network relationship among the microorganisms. The total carbon (TC) plays an important role in regulating the composition of microbial community. The microbial community in roadside slope is dominated by stochastic processes, while the strong interspecies interactions and selection effect of asphalt on microbial community strengthen the role of deterministic processes in remodeling the microbial community structure in asphalt pavement. This study is of great significance for understanding the biological aging mechanism of asphalt pavement.

Development of high-efficient asphalt pavement modeling software for digital twin of road infrastructure

To develop digital twin (DT) of road infrastructure, one critical element is computation of pavement responses (strains, stresses, and deflections) under traffic and environmental loading. This study aims to develop high-efficient asphalt pavement modeling software based on semi-analytical finite element method (SAFEM) for DT application. The algorithms address important aspects in vehicle-tire-pavement interaction modeling, such as dynamic vehicular loading, three-dimensional (3-D) non-uniform tire contact stress, viscoelastic behavior of asphalt material, and interface bonding condition. The simulation accuracy is verified by comparison with full-scale test and field measurements, and the relative differences are around 5 % to 20 %. Techniques including optimized discrete Fourier transform, parallel computing, graphics processing unit (GPU) acceleration, and sparse matrices are implemented for computation efficiency. As compared to the traditional 3-D FEM, SAFEM shows significant savings in computation time and storage usage. The high efficiency and accuracy make the software full of potential to be applied for DT of roadway infrastructure.

Effect of evaporation temperature on evaporative residue properties of waterborne polyurethane modified emulsified asphalt

Abstract In recent years, waterborne polyurethane (WPU) modified emulsified asphalt has attracted much attention. The conventional property of WPU-modified emulsified asphalt (WPU-MEA) is usually measured by using the evaporative residue obtained at high temperatures. In this work, WPU-MEA was prepared and the influence of evaporative temperature on the conventional performances (softening point, penetration, ductility) of the residue of WPU-MEA was investigated. Fourier Transform Infrared Spectroscopy (FTIR) and Fluorescence microscope (FM) were used to analyze the chemical structure and morphology of the evaporative residues. It was found that the evaporation dehydration temperature has a significant influence on the property of the evaporation residue of WPU-MEA. The evaporative residue performance of WPU modified asphalt was better at an evaporation temperature of 110°C, and the three conventional properties were significantly improved. Upon increasing the evaporation temperature, the conventional properties of WPU-MEA continue to decrease. As the evaporation temperature is 190°C, the conventional property of the residue is close to that of unmodified emulsified asphalt. Considering the performance index of WPU-MEA, the optimal evaporation temperature should be determined in the characterization of residue performance. This study has a guiding significance for the development of polyurethane-modified asphalt materials.

The influence of residual asphalt material in the mechanical behaviour of soil-RAP mixtures for use in paving

ABSTRACT The evaluation of Reclaimed Asphalt Pavement (RAP)’s suitability for pavement layers, optimises resource use, reduces environmental impact, and supports cost-effective practices. In this sense this study aimed to characterise soil-RAP mixtures to ensure they meet the quality standards required for pavement applications. The study examined two types of soil mixtures: one soil-RAP aggregates and the other soil-virgin aggregates (VAM) to understand the impact of residual asphalt binder on aggregate particles. Various mass contents (30%, 50%, 70%, and 90%) were tested alongside conventional soil-gravel mixtures with equivalent proportions and gradation of RAP and VAM. Additionally, the study investigated the effect of adding 2% cement on the performance of both recycled soil-RAP mixtures and conventional soil-gravel mixtures. The analysis includes granulometry, Atterberg Limits, MCT (Miniature, Compacted, Tropical) classification, soil chemical characterisation and microscopic images, compaction in Modified Proctor Energy, CBR, Resilient Modulus tests and stress–strain analysis. The results have revealed that the residual asphalt binder, surrounding RAP aggregates, has reduced the soil mixtures’ strength for different RAP contents. However, the study demonstrated that the addition of cement rendered the soil-RAP mixture feasible, enabling the application of the studied mixtures of RAP to constitute subbase and base layers.

Analysis of short-term self-healing performance of asphalt mixture under a three-point bending fatigue test

To evaluate the self-healing performance of asphalt mixture under repeated loads, indoor three-point bending fatigue tests and self-healing tests were conducted on asphalt mixture AC-13. The stress control mode was selected to test the fatigue resistance of the mixture, and the dissipated energy recovery value and visco-elastic ratio were proposed to evaluate the self-healing performance of the mixture. The experimental results show that there is a good linear relationship between fatigue life and fatigue stress, and the damage degree to the mixture is exponentially related to the load times. The numerical dispersion of flexural tensile modulus is large, which is not suitable for evaluating the self-healing performance of the mixture. As the number of loading cycles increases, the hysteresis dissipated energy of the mixture gradually decreases and tends to stabilize. After the loading interval, due to the self-healing effect, the visco-elastic performance of the asphalt material is partially restored. The initial dissipated energy before and after interval can be used as an evaluation index for self-healing behavior, and there is a good linear relationship between the initial dissipated energy and the damage degree. Due to the deformation migration of the mixture during the initial loading stage before and after interval, the visco-elastic ratio has changed, and this change becomes more pronounced with the damage degree of the mixture, indicating that the self-healing ability of the mixture has also been improved.

Study on the Performance of Modified Qingchuan Rock/Rubber Asphalt

This paper developed a new environmentally friendly composite modified asphalt material and studied the composite modification of Qingchuan rock asphalt (QRA) and waste tire rubber powder (RP) was studied in this paper. QRA/RP composite modified asphalt was prepared by adding these two materials as modifiers into matrix asphalt and compared with matrix asphalt and QRA modified asphalt. The basic properties of asphalt before and after aging were evaluated by the rotating thin film oven test. The high-temperature performance and permanent deformation resistance at different temperatures and frequencies were analyzed by the dynamic shear rheological test. The bending creep stiffness test was used to evaluate the low-temperature performance. In addition, the microstructure and modification mechanism of composite-modified asphalt were analyzed by scanning electron microscopy and infrared spectroscopy. The results show that QRA-modified asphalt is superior to matrix asphalt in terms of mass loss, viscosity ratio, and residual penetration, while QRA/RP composite-modified asphalt is further improved on this basis, QRA/RP composite modified asphalt can effectively improve the high and low temperature performance of asphalt.. Although the addition of RP is mainly based on physical modification, it also causes weak chemical reactions and enhances the adhesion of asphalt. The interaction between Qingchuan Rock asphalt and rubber powder significantly improves the overall stability of asphalt structure.

Research on the Rheological Performance of Fast-Melting SBS-Modified Asphalt under Complex Environmental Factors

Currently, fast-melting SBS (Styrene-Butadiene-Styrene)-modified asphalt is widely used in pavements. However, in practical applications, complex environmental factors accelerate the deterioration of asphalt material properties, significantly affecting the service life of roads during their operational period. This study aims to examine the effects of complex environmental factors, including thermal oxidation, ultraviolet radiation, and various concentrations of salt solutions, on the high and low-temperature rheological properties of fast-melting SBS-modified asphalt (abbreviated as SBS-T-modified asphalt). Pressure aging–ultraviolet aging coupling and pressure aging–ultraviolet aging different concentration salt solution coupling were selected as the aging groups to simulate complex environmental conditions. Additionally, base asphalt and pressure-aged asphalt were used as control groups. The rheological properties of SBS-T-modified asphalt were evaluated using a dynamic shear rheometer (DSR) and bending beam rheometer (BBR). The results indicate that multiple-factor coupling aging reduces both the high-temperature and low-temperature performance of SBS-T-modified asphalt compared to single-factor aging, although the impact on rheological properties is not consistent across all conditions. After the combined effects of UV aging and pressure aging, the rutting resistance and high-temperature performance of SBS-T-modified asphalt are most severely impacted. However, when coupled with salt-solution aging, the rutting resistance of SBS-T-modified asphalt improves, with the complex modulus increasing by approximately 30%. This indicates that the presence of the salt solution enhances the high-temperature performance of the asphalt. An analysis of the low-temperature rheological properties of SBS-T-modified asphalt based on Burgers model shows that the low-temperature rheological performance of SBS-T-modified asphalt worsens under three-factor coupling aging compared to two-factor or single-factor aging, leading to poorer crack resistance. Notably, after adding salt solutions, the thermal sensitivity of SBS-T-modified asphalt increases significantly, with the ΔTc value decreasing approximately sixfold for every 2% increase in salt concentration.

Polydopamine‐modified black phosphorus/microcapsule composite material used to enhance the solar thermal conversion and self‐healing performance of SBS modified asphalt

AbstractThis study developed UV‐responsive microcapsules to enhance the self‐healing properties of asphalt, addressing the limitations of low survival rates and single‐release mechanisms in current encapsulated rejuvenators. The microcapsules, featuring a urea‐formaldehyde shell embedded with polydopamine‐coated black phosphorus nanosheets (BP/DA) and microalgae bio‐oil as the core, can convert solar energy into thermal energy, promoting proactive self‐healing in asphalt materials. BP/DA expands the microcapsules' light absorption range, enhancing their photothermal conversion efficiency. When incorporated into styrene‐butadiene‐styrene (SBS)‐modified asphalt at a 1.5% dosage, the microcapsules (BP/DA/MC) improved the mechanical properties: ductility increased by 13.7%, softening point rose by 2%, and penetration decreased by 3.3%. The storage modulus (G′) at 46 and 64°C increased by 35.9% and 24.3%, respectively, compared to SBS asphalt. Additionally, the ductility self‐healing rate of BP/DA/MC/SBS asphalt improved by 209.7%, with a healing index (HI) of 78.16%. The microcapsules also demonstrated excellent photothermal conversion, increasing the asphalt's temperature by 22.6% under identical lighting conditions. This research offers a new method for developing intelligent self‐healing asphalt with multi‐mechanism activation, providing theoretical support for future third‐generation microcapsule‐based asphalt with remote‐controlled release and activation response.

Characterizing the Self‐Healing Asphalt Materials: A Neutron Imaging Study

Given the significant role of asphaltic pavement in surface transportation systems, even minor enhancements in asphalt materials hold the potential for cost savings and reduced environmental impacts. The healing properties of asphalt have drawn interest for sustainability, yet much remains unknown about the causes and influencing factors. To leverage self‐healing for extending pavement life, understanding the mechanisms and conditions that stimulate microcrack healing is essential. This study aims to investigate the dynamic progress of microcrack closure in asphalt mastics. The time‐series evolution of crack closure led by self‐healing is tracked by neutron computed tomography, with image processing facilitating volumetric analysis over a 7 h period. The study examines the healing process in mastic samples with three different sand filler contents (10, 20, and 30%). Results show that for all the investigated samples, the healing rate declines exponentially over time, with 100% recovery not achieved after 7 h at room temperature. Filler content‐influenced healing speed and 20% sand demonstrate the best performance. Meanwhile, the healing performance varies within the 10% and 30% groups, depending on initial crack size. Additionally, the study finds that initial crack size influences healing behavior in the samples.

Rehabilitation and reinforcement of cracked pavements using crack sealers and composite patches

Cracking is a significant concern for pavements and should be appropriately treated during road, highway, and runway rehabilitation. This study investigates the behavior of asphaltic materials under tensile and shear loading modes in intact, fractured, and repaired conditions. With this aim, several methods and materials are utilized for repairs, such as poring adhesive into the crack (using bitumen, neat epoxy resin, and polymer concrete adhesives) and patching the crack with textile (by glass fiber and epoxy resin or bitumen). These tests were conducted at +10 °C, with a three-point bending loading configuration, the same as the actual loading configuration of pavements. Criteria such as failure load, failure work, and post-failure work, as well as failure patterns, were assessed to assess the effectiveness of repairs. Numerical analysis was also performed, and a constitutive model was presented. The ultimate tensile capacity of the cracked specimen is measured at 63 % lower than the intact condition (778 N). The ultimate tensile load of the bitumen-repaired specimen is higher than that of the cracked specimen, but it is still 11 % lower than that of the intact condition. The ultimate tensile capacity of epoxy resin repaired and polymer concrete repaired specimens are 88 % and 79 % higher than the intact specimen (about 1400 N). The ultimate tensile load of the fabric patch reinforced specimen that used bitumen as the adhesive is 38 % higher than the intact specimen (1075 N), while for the case of using the epoxy resin adhesive, this value is 258 % (2788 N). Observations of tensile failure patterns show that, because bitumen is viscoelastic, failure in bitumen-repaired specimens happens in bitumen necking mode and starts at the repaired crack tip. In other cases, the failure occurred far from the pre-crack plane.

Utilization of Buton Granular Asphalt (BGA) as Asphalt and Filler Content Substitution Material – in Asphalt Concrete Mixture- Wearing Course

Roads are one of the infrastructure that is urgently needed in improving the accessibility of an area and has a crucial role as a connecting infrastructure that facilitates the transportation of people and goods. This road must be able to handle the volume of traffic according to the plan, so planning must ensure smooth transportation. Asbuton can be used as a binding material on road pavements. However, the use of buton asphalt as a road construction material in Indonesia has not had a significant impact on infrastructure development carried out by the government. The purpose of this study is to analyze the characteristics of Marshall’s test value using Buton Granural Asphalt as a substitute for filler and Fine Aggregate in the mixture of Asphalt Concrete – Wearing Course (AC – WC). The type of data used is primary data obtained from laboratory test results and secondary data obtained from SNI Bina Marga 2018 rev.2. The results showed that with the addition of 19% BGA (Buton Granular Asphalt) as a filler and fine aggregate material, the stability of the mixture could be increased up to 2369,8 kg with the addition of BGA, when compared to aggregate without BGA, the stability value was higher. Based on the test of the characteristics of the 0% BGA mixture marshall obtained a density value of 2,304 t/m³, stability of 1240,6 kg, fatigue of 3.4 mm, Marshall Quotient (MQ) of 366,0 kg/mm, VMA of 16,3%, VFB of 76.2%, VIM of 3.9%. Marshall testing on a mixture of 19% BGA obtained a density value of 2325,0 t/m³, Stability of 2369,8 kg, Fatigue of 3.4 mm, Marshall Quotient(MQ) of 697,1 kg/mm, VMA of 15,4%, VFB of 80,0%, VIM of 3.1%. All test parameters meet the standards set out in the 2018 General Bina Marga specification for revision 2 road and bridge construction work, so that AC-WC asphalt concrete with 0% and 19% BGA substitution can be used.

Components optimization of polyurethane-modified asphalt binder towards compatibility: Insight from molecular dynamics simulations

Polyurethane-modified asphalt demonstrated the enhanced durability and skid resistance, while remaining the drawback in the compatibility between the polyurethane modifier and asphalt binder in practical use. Herein, a molecular-dynamics-simulations based compatibility evaluation method is proposed for the polyurethane modifier and asphalt binder, thereby achieving the cost-effective and efficient components optimization. Twelve components asphalt molecular model was built in Molecular Dynamics to investigate the interaction of asphalt binder to the polypropylene glycol, toluene diisocyanate, and diphenylmethane diisocyanate, respectively. The molecular model of polyurethane modified asphalt binder was verified by the similar loss modulus temperature from the simulation and temperature scanning tests. The simulation outcomes indicate significant variations in the compatibility of different polyurethanes with asphalt, in which diphenylmethane diisocyanate-type polyurethane exhibits the superior compatibility. The compatibility of various polyurethane concentrations in asphalt shows considerable disparity, suggesting that the compatibility index can serve as a criterion for determining the optimal dosage of the modifier. Temperature also exerts an influence on the compatibility of polyurethane modified asphalt binder. Simulation results indicates that 130 °C potentially may be the optimal temperature for its preparation, which is corroborated by the microscopic characterization. This study provides a fundamental framework for the molecular dynamics simulation-based components optimization of polyurethane-modified asphalt, thereby inspiring the targeted design of asphalt materials.

Large-scale molecular dynamics simulation and aggregate behavior research on asphalt

In this comprehensive study, a molecular dynamics (MD) model consisting of approximately 150,000 atoms was developed within the Strategic Highway Research Program (SHRP) framework to investigate the behavior of AAA asphalt, focusing on asphaltene aggregate dynamics behavior over a simulation time span of 0.282 microseconds. The findings reveal that the model achieves a stable state in terms of both energy and microstructure without significant changes or the formation of densely clustered molecules, despite the extensive simulation period. Notably, the patterns of asphaltene aggregation were found to significantly influence the MD system energy, with variations ranging from loosely organized structures due to dispersed asphaltenes to more structured, energy-efficient clusters formed by encapsulated asphaltene pentamers. The size of asphaltene aggregates emerged as a pivotal factor, affecting their encapsulation and leading to distinct formation patterns. Furthermore, the research highlighted that increasing shear rates prompt the depolymerization of asphaltene aggregates, shifting from large-scale structures to smaller ones and adapting dynamically to the flow conditions by aligning parallel to the shear direction. This study underscores the critical impact of asphaltene aggregate behavior and shear rates on the structural integrity and distribution within the asphalt model, offering profound insights into the MD of asphalt materials.

Preparation and Performance Study of Ultraviolet-Responsive Self-Healing Epoxy Asphalt.

In this study, a self-healing epoxy asphalt material was developed by incorporating coumarin groups. This material achieved microcrack self-repair under UV irradiation at 50 °C. Fluorescence microscopy observations and mechanical performance tests demonstrated significant advantages in crack filling and mechanical property recovery after repair, with the fracture toughness of the repaired epoxy asphalt reaching 69% of that in its original state. Furthermore, the synergistic effect of temperature and UV irradiation in the self-healing process enhanced the material's durability and service life. This research offers new insights and methods for developing more durable and long-lasting self-healing asphalt materials, showcasing the great potential of smart materials in infrastructure applications.

Rheological and Aging Properties of Nano-Clay/SBS Composite-Modified Asphalt.

Nano-organic montmorillonite (OMMT) not only inhibits the harmful asphalt fume generation during the production and construction processes of asphalt mixtures but also effectively improves the performance of asphalt pavements. In order to prepare asphalt materials with smoke suppression effects and good road performance, this study selects nano-OMMT and SBS-modified asphalt for composite modification of asphalt mixtures and systematically investigates its road performance. Through the temperature sweep test, the frequency sweep test, the multiple stress creep recovery (MSCR) test, the bending beam rheometer (BBR) test, and the atomic force microscope (AFM) test, the high-temperature rheological properties, low-temperature rheological properties, high-temperature properties and aging resistance of the modified asphalt are studied. The research findings indicate that OMMT can effectively reduce the sensitivity of modified asphalt to load stress and improve its high-temperature rheological properties. SBS-modified asphalt shows increased creep stiffness and a decreased creep rate after OMMT modification, resulting in reduced flexibility and decreased low-temperature crack resistance. After short-term and long-term aging, the complex modulus aging index of OMMT/SBS composite-modified asphalt is lower than that of SBS-modified asphalt, and the phase angle aging index is higher than that of SBS-modified asphalt, demonstrating that OMMT enhances the aging resistance of SBS-modified asphalt. OMMT inhibits oxidation reactions in the asphalt matrix, reducing the formation of C=O and S=O bonds, thereby slowing down the aging process of modified asphalt and improving its aging resistance.