Short-term Aging Research Articles

Physics-informed machine learning for battery degradation diagnostics: A comparison of state-of-the-art methods

Monitoring the health of lithium-ion batteries’ internal components as they age is crucial for optimizing cell design and usage control strategies. However, quantifying component-level degradation typically involves aging many cells and destructively analyzing them throughout the aging test, limiting the scope of quantifiable degradation to the test conditions and duration. Fortunately, recent advances in physics-informed machine learning (PIML) for modeling and predicting the battery state of health demonstrate the feasibility of building models to predict the long-term degradation of a lithium-ion battery cell’s major components using only short-term aging test data by leveraging physics. In this paper, we present four approaches for building physics-informed machine learning models and comprehensively compare them, considering accuracy, complexity, ease-of-implementation, and their ability to extrapolate to untested conditions. We delve into the details of each physics-informed machine learning method, providing insights specific to implementing them on small battery aging datasets. Our study utilizes long-term cycle aging data from 24 implantable-grade lithium-ion cells subjected to varying temperatures and C-rates over four years. This paper aims to facilitate the selection of an appropriate physics-informed machine learning method for predicting long-term degradation in lithium-ion batteries, using short-term aging data while also providing insights about when to choose which method for general predictive purposes.

Effects of rejuvenators and aging conditions on the properties of blended bitumen and the cracking behavior of hot asphalt mixtures with a high RAP content

The utilization of Reclaimed Asphalt Pavement (RAP) in asphalt pavement has obtained global popularity because of its cost-efficiency, technical advantages, and positive environmental influence. However, incorporating RAP requires careful consideration of cracking resistance because of the existence of age hardening of bitumen in RAP. For the mixtures containing high RAP contents, rejuvenators are often applied to enhance the performances of aged bitumen and the cracking of mixtures. This research aims to evaluate the effects of different rejuvenators on the rheological properties of bitumen and the cracking resistance of the mixture under short and long-term aging conditions. To achieve this goal, three rejuvenators - namely, RA1 (petroleum-based), RA2 (waste vegetable oil-based), and RA3 (modified soybean oil-based) were evaluated at contents of 0%, 4%, 12%, and 20%, respectively. The dynamic shear rheometer (DSR) test results show that, under unaged and rolling thin-film oven (RTFO) aging conditions, blended bitumen with RA1 and RA3 have higher G*/sinδ than RA2. Conversely, under pressure aging vessel (PAV) aging conditions, blended bitumen with RA1 and RA3 has lower G*sinδ than that with RA2. Regarding the cracking resistance, the indirect tension asphalt cracking test results show that, under short-term oven aging (STOA) conditions, the mixture using RA2 and RA3 has a higher cracking tolerance index (CTIndex) than the one with RA1. However, under long-term oven aging (LTOA) conditions, the mixture using RA1 has the highest CTIndex value. In addition, the high correlations between G*sinδ with CTIndex and post-peak slope (|m75|) and between the CTIndex and |m75| are observed.

A Method for Assessing the Degradation of PVC-Insulated Low-Voltage Distribution Cables Exposed to Short-Term Cyclic Aging

The distribution grid comprises cables with diverse constructions. The insulating material used in low-voltage (LV) distribution cables is predominantly PVC. Furthermore, the presence of cables with different structures in the grid poses challenges in detecting the aging of the cable network. Finding a universal and dependable condition-monitoring technique that can be applied to various types of cables is indeed a challenge. The diverse construction and materials used in different cables make it difficult to identify a single monitoring approach that can effectively assess the condition of all cables. To address this issue, this study aims to compare the thermal aging behavior of different LV distribution cables with various structures, i.e., one cable contains a PVC belting layer, while the other contains filler material. The growing adoption of distributed generation sources, electric vehicles, and new consumer appliances in low-voltage distribution grids can lead to short, repetitive overloads on the low-voltage cable network. Hence, these cable samples were exposed to short-term cyclic accelerated aging in the climate chamber at 110 °C. The cable’s overall behavior under thermal stress was evaluated through frequency and time domain electrical measurements (including tan δ and extended voltage response) and a mechanical measurement (Shore D). The tan δ was measured in the frequency range of 20 Hz–500 kHz by using the Wayne-Kerr impedance analyzer. The extended voltage response measurement was conducted using a C# application developed in-house specifically for laboratory measurements in the .NET environment. The study observed a strong correlation between the different measurement methods used, indicating that electrical methods have the potential to be adopted as a non-destructive condition-monitoring technique.

Influence of Short-Term Aging Treatment on Precipitation Behavior of DD6 Single-Crystal Superalloy

Influence of Short-Term Aging Treatment on Precipitation Behavior of DD6 Single-Crystal Superalloy

Bio-Modified Bitumen: A Comparative Analysis of Algae Influence on Characteristic Properties

The main aim of this study was to identify and evaluate the characteristic properties of bitumen modified with algae. Two types of algae, each with distinct gradation and origin, were employed for this investigation. For each type of algae (noted as chlorella and microchlorella), three blends were created with varying algae contents (5%, 10%, and 15% by weight of bitumen), utilizing a 70/100 reference bitumen as the virgin material and a basis for comparison. The properties of the blends were investigated using the Penetration, Softening Point, Elastic Recovery, Force Ductility, Dynamic Viscosity, and Storage Stability tests, both before and after short-term ageing (TFOT). The test results were then used to calculate the Activation Energy (Ea), Viscosity-Temperature Susceptibility (VTS) Index, and Mixing Temperature (Tmixing), along with their respective Pearson Correlation Coefficient (PCC) and R2 and p-values. The main finding of the study was that the addition of a low algae content of 5% caused a change in the classification of the unaged bitumen from 70/100 to 50/70 according to EN 12591 and thus hardened the reference bitumen. Additionally, a strong linear statistical correlation was observed between Ea and the VTS index, suggesting that these values should be considered when characterizing the temperature susceptibility of algae-modified bitumen.

WITHDRAWN: Investigating the Polymer Structure Effects on SBS-Modified Asphalt Binders under Short-Term Aging through the Artificial Neural Networks, Genetic Algorithms, and Fuzzy Logic

SBS-modified asphalt (SBSMA) exhibits complicated aging behavior in the weathering environment due to oxidation of the matrix asphalt, degradation of the SBS, and disruption of the SBS-asphalt relationship. The weathering process of SBS-modified asphalt has been studied extensively. However, most of this research has taken a broad, environmental approach. This research delved into the nuanced effects of aging on low polymer-modified asphalt (LPMA) compositions integrated with a rejuvenating agent (RA), leveraging advanced computational intelligence methodologies. The study uniquely employed fuzzy logic, Artificial Neural Networks (ANN), and genetic algorithms to forecast and analyze the performance dynamics of distinct asphalt mixtures. Five asphalt mixtures were examined: a PG 58-28 binder served as the foundational benchmark, while the subsequent four used modified PG 58-28 with different ratios of Ethylene Vinyl Acetate (EVA) and sesame oil (RA). Assessment methodologies comprised the Resilient Modulus Test, Wheel Track Test, Flow Time, Direct Tension, and Quarter-Circle Bend tests. The ANN framework was instrumental in predicting rutting and crack trajectories, while fuzzy logic facilitated understanding the intricate interplays between component ratios and resultant performance metrics. Genetic algorithms optimized the EVA and RA ratios for enhanced efficacy. Initial results demonstrated that the amalgamation of EVA and RA strengthened the overall lifespan and rutting resilience of the asphalt composites. Enhanced blends, optimized using the genetic algorithm, exhibited improved resistance to initial crack formations relative to the baseline. As the aging process advanced, the modified blend's resilience to recurrent stress-induced cracks experienced minor reductions but paralleled the foundational benchmark. A harmonized combination, pinpointed via the genetic algorithm containing 6.5% EVA and 6% RA, emerged as the most proficient in amplifying durability, resistance against deformations, and immediate crack resistance.

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.

Precipitation behavior and mechanical property evolution in a solid solution strengthened Ni-Cr-W superalloy during short-term aging

The precipitation behavior and mechanical property evolution of a superalloy, Haynes 230, were investigated during short-term aging at 800 ℃. The results demonstrated that M6C and four different forms of M23C6 precipitated throughout aging, and the evolution of M23C6 followed a sequence of intergranular precipitates, intragranular nano-precipitates, incoherent twin boundary (TB) precipitates, and peritectic precipitates enveloping the outer layer of M6C, all of which exhibited a semi-coherent cubic-to-cubic relationship with the austenitic matrix. Among them, the intergranular M23C6 was mainly lamellar. The lamellar M23C6 formed through a discontinuous reaction, resulting from the decomposition of the supersaturated matrix and alternating with the γ matrix. Intragranular nano-M23C6 precipitated preferentially at dislocations, while incoherent TB M23C6 grew along the {111} direction of the twin plane. In addition, peritectic M23C6 was a product of the degradation reaction of M6C at 800 ℃, with higher W and Cr than the other forms of M23C6. Overall, the significant changes in microstructure and properties of alloy 230 during aging at 800 ℃ were concentrated in the first 200 h. At this stage, the precipitation amount of carbides increased dramatically, which enhanced the strength and hardness to peaks by hindering the dislocation motion. Meanwhile, ductility and toughness decreased significantly on account of the reduction of grain boundary bonding strength caused by lamellar M23C6. With the extension of aging time, the tensile fracture mode at room temperature shifted from transgranular to intergranular fracture, and intergranular M23C6 gradually became the preferential crack source.

Development of a Framework for Assessing Bitumen Fatigue Cracking Performance under Different Temperatures and Aging Conditions

A full understanding of bitumen fatigue cracking behavior is extremely important as this phenomenon has a considerable influence on bituminous pavement performance. The current framework for assessing this asphalt binder property is inconsistent in ranking bitumen fatigue performance in terms of the failure definition and damage characteristic curve (DCC) analysis. This study used four different types of asphalt binders: neat asphalt (NA), self-healing thermoplastic polyurethane (STP)-modified bitumen, self-healing poly (dimethyl siloxane) crosslinked with urea bond (IPA1w)-modified bitumen, and styrene–butadiene–styrene (SBS)-modified bitumen (SBSB). All the bitumens were subjected to short-term and long-term aging, and they were also tested by utilizing the linear amplitude sweep (LAS) test and the simplified viscoelastic continuum damage (S-VECD) model. LAS and S-VECD procedures were used to apply the newly proposed and current frameworks in order to analyze bitumen performance. The current framework showed that the bitumens that used a higher number of loading cycles (N) to reach their failure points (Nf) failed to exhibit greater fatigue performances in terms of DCC analysis. The developed framework (mainly based on the damage intensity [S] instead of N) was used to solve the inconsistency between the failure definition and DCC assessment in ranking bitumen performance. Additionally, the current framework (failure criterion) presented two R2 values below 0.1, but the developed framework (failure criterion) showed that all R2 values were greater than 0.9. The developed framework represents a turning point because, for the first time, this type of procedure is mainly being based on S instead of N. Although further tests are needed to confirm its efficiency, it eliminates the inconsistency between the failure definition and DCC assessment.

Investigation of Phenolic Resin-Modified Asphalt and Its Mixtures.

This study comprehensively examines the influence of phenol-formaldehyde resin (PF) on the performance of base asphalt and its mixtures for road applications, emphasizing its innovative use in enhancing pavement quality. Optimal PF content was determined through the evaluation of standard indicators and rotational viscosity. In-depth analyses of PF-modified asphalt's high- and low-temperature rheological properties and viscoelastic behavior were conducted using dynamic shear rheometers and bending beam rheometers. Aging resistance was assessed through short-term aging and performance grade (PG) grading. Moreover, Marshall and water stability tests were performed on PF-modified asphalt mixtures. Findings indicate that the uniform dispersion of PF particles effectively inhibits asphalt flow at high temperatures, impedes oxygen penetration, and delays the transition from elasticity to viscosity. These unique properties enhance the high-temperature stability, rutting resistance, and aging resistance of PF-modified asphalt. However, under extremely low temperatures, PF's brittleness may impact asphalt flexibility. Nonetheless, the structural advantages of PF-modified asphalt, such as improved mixture density and stability, contribute to enhanced high-temperature performance, water stability, adhesion, and freeze-thaw cycle stability. This research demonstrates the feasibility and effectiveness of using PF to enhance the overall performance of base asphalt and asphalt mixtures for road construction.

Influence of rejuvenator components on rheological properties of recycled bitumen in the full temperature range

Recovering aged bitumen from reclaimed asphalt pavement (RAP) is crucial for the evolution of pavement recycling. This study delves deeply into the effects of rejuvenator components on the rheological properties of rejuvenated bitumen across a wide temperature range. The investigation utilized the rolling thin film oven test (RTFOT) and the pressure aging vessel (PAV) test to simulate the short-term and long-term aging of the bitumen binder, respectively. Four distinct rejuvenators were then applied to recover the bitumen at varied aging levels. Detailed chemical analyses, encompassing the four-fraction (SARA) method and Fourier transform infrared spectroscopy (FTIR), were employed to identify the chemical compositions and key functional groups of both the rejuvenators and the rejuvenated bitumen. The rheological behavior of rejuvenated bitumen was assessed through a comprehensive series of tests, including conventional, temperature sweep, frequency sweep, multiple stress creep recovery (MSCR), linear amplitude sweep (LAS), and bending beam rheometer (BBR) tests. A Pearson correlation analysis highlighted a significant positive association between specific rejuvenator components, notably asphaltene (As), saturate (S), and aromatic (Ar), and the high-temperature performance of the rejuvenated bitumen. The findings of this research offer insights into the formulation of rejuvenators, potentially enhancing the performance of rejuvenated asphalt pavements and facilitating sustainable infrastructure advancements.

Laboratory test of physical, rheological, and chemical characteristics of aging binder modified with ZycoTherm and Evotherm

The research aims to comprehensively assess the impact of anti-stripping agents ZycoTherm and Evotherm M1 on Warm Mix Asphalt (WMA). The study employs a range of laboratory tests to investigate the rheological and chemical properties of modified asphalt. Conventional tests such as penetration and ring & ball softening points are employed alongside advanced techniques including Dynamic Shear Rheometer (DSR), and Linear Amplitude Sweep (LAS) analyses to delve into the rheological properties. Chemical properties (SARA) were analyzed using thin-layer chromatography. Both short-term aging (STA) using The Rolling Thin-Film Oven (RTFO) and long-term aging (LTA) based on the Universal Simple Aging Test are simulated under controlled laboratory conditions. It was found in conventional tests that the value changed, but not significantly. In terms of rutting and fatigue performance, Zyc 0.05% showed positive results. Fatigue behavior shows Zyc has better resistance. The asphalt fractional composition test showed changes in each age condition.

Numerical and experimental study on the low temperature rheological performance of basalt fiber reinforced asphalts

The low temperature rheological performance of basalt fiber reinforced asphalts (FRAs) is studied using finite element (FE) simulations and experimentations. First, a bending beam rheological (BBR) test of the pure asphalt is simulated using Abaqus, to build a basic pure asphalt BBR model. The simulation results of the pure asphalt specimen, obtained using the viscoelastic parameters derived either from the Burgers transformation method (BTM) already available in the literature or from a novel mathematical iteration method (MIM), are compared with experimental data, to choose the most reliable approach. Second, a virtual 3D FRA model is generated using Matlab. Different simplification methods pertaining to fibers forming the bundles are considered to further compare the simulation results with the experimental ones. Some FRA models with different fiber orientations are simulated and compared. Finally, the pure asphalt and FRA samples are tested and simulated under short and long term aging processes. The results show that the BBR model of the pure asphalt with parameters obtained from the iteration method is closer to the original experiment. A larger creep stiffness and a lower m-value are observed when considering less fibers clustered in bundles. The results obtained in the BBR test are dependent on the effective contact area between fibers and asphalt. In agreement with intuition, the creep stiffness turns out to be higher when the fiber orientation is constrained to be horizontal, and it progressively reduces for models with randomly and vertically distributed fibers. The creep rate shows an opposite trend. Finally, aging can increase the creep stiffness and decrease the creep rate of pure asphalt and FRA, and it is suggested to consider less fibers to simulate the bundles in order to improve the accuracy of the FE models against experimental data.

Viscous Flow Activation Energy and Short-Term Aging Resistance of SBS-Modified Asphalt Enhanced by PPA Oil-Grinding Activated MoS<sub>2</sub>

Viscous Flow Activation Energy and Short-Term Aging Resistance of SBS-Modified Asphalt Enhanced by PPA Oil-Grinding Activated MoS<sub>2</sub>

Effects of Lactiplantibacillus plantarum dy-1 fermentation on multi-scale structure and physicochemical properties of barley starch.

The effects of fermentation on barley starch were studied using Lactiplantibacillus plantarum dy-1. Changes in multi-scale structure and physicochemical properties of barley starch were studied. The chain structure results revealed that fermentation could increase the content of short chain and medium short chain by breaking down long amylopectin side chains in barley and increase amylose content by debranching amylopectin. Also, fermentation promoted the arrangement of short chains into short order structure, leading to the enhancement of hydrogen bond interaction. Furthermore, it improved the helical structure content and relative crystallinity of barley starch by degrading the amorphous structure of barley starch. In terms of physicochemical properties, fermentation inhibited the hydration characteristics of barley starch, thus improving its thermal stability. It also enhanced shear stability, resistance to short-term aging and digestion, and improved gel texture properties. These findings offer potential for the processing and nutritional regulation of fermented barley products.

Study on the Rule and Mechanism of Short-Term Aging of SBS Modified Asphalt

Study on the Rule and Mechanism of Short-Term Aging of SBS Modified Asphalt

Laboratory short-term aging of crumb rubber modified asphalt: RTFOT temperature optimization and performance investigation

Improper disposal of substantial scrap tires can result in significant environmental issues, such as air pollution, water resources, and soil contamination. The scrap tires can be turned into valuable materials by preparing tire rubber powder into Crumb rubber modified asphalt (CRMA). This method can effectively reduce environmental pollution and achieve the concept of energy conservation, environmental protection, and low-carbon. However, during the production process of CRMA mixtures, the elevated construction temperature may induce more severe short-term aging of the mixtures. The standard laboratory short-term aging scheme of asphalt binders, the Rolling Thin Film Oven Test (RTFOT), cannot simulate the short-term aging of CRMA due to the increase in construction temperature. Besides, the determination methods and indices of RTFOT aging temperature are still unclear and inconsistent. In this study, three CRMA binders were treated by RTFOT with five temperatures, and the short-term oven aging (STOA) protocol was conducted on CRMA mixtures with three types of gradations. Firstly, the chemical and rheological performance of CRMA binders and mixtures were investigated by conducting Gel permeation chromatography (GPC), Fourier transformation infrared spectroscopy (FTIR), Dynamic shear rheology (DSR) tests, and Bending beam rheometer (BBR) test. Then, the equivalent aging temperatures were determined to optimize RTFOT temperatures by comparing the chemical indicators of binders and mixtures. Finally, the correlations of chemical and rheological indices were established, and the rheological properties of aged asphalt in mixtures were predicted. The analysis results indicate that suitable RTFOT temperature is not only related to the technical routes and viscosity of CRMA binders, but also relevant to the mixture gradations. Binders with higher viscosity need elevated RTFOT temperatures from 173 °C to 193 °C, especially simulating short-term aging of mixtures with higher air voids. The swelling and degradation of crumb rubber contribute to the enhancement of the anti-aging performance. The aging index (AI) can reflect the anti-aging performance of CRMA binders, and the variation of AI can validate the rationality of the optimized RTFOT temperatures.

Anti-aging effect of TMQ on EPDM for Various Cure Systems

Ethylene propylene diene rubber (EPDM) is a common raw material for weather resistant rubber products used in lots of areas such as cable, automotive, marine industry and aviation applications. Superior processing behaviour, electrical properties and moderate high temperature resistance also make EPDM an attractive raw material for a wide range of further industrial performance requirements. As well as the other general purpose rubbers, EPDM needs to be protected against thermo-oxidative aging. Short and long term aging behaviour of both sulphur and peroxide cured EPDM has been studied in literature. However, to the authors’ best knowledge, there is not any study in literature systematically evaluating a common rubber antioxidant 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ) for investigating theoretical life-time of EPDM based materials that were vulcanized with different crosslinking systems. In this study, effects of TMQ on the thermo-oxidative resistance of EPDM has been studied for conven-tional and efficient sulphur vulcanization systems as well as peroxide vulcanization system. Aging mechanism for different cases has been investigated by using structural, rheological and mechanical tests. Thermo-oxidative aging has been monitored by carbonyl index and activation energy. Arrhenius based life-time estimation methodology has also been employed to evaluate aging behaviour of the reference and TMQ containing (-T) compounds. TMQ was found to exhibit different levels of protection against thermo-oxidative aging for all the curing systems and at all aging conditions. Higher aging activation energy for -T compounds has been attributed to extended service life of the material in the presence of TMQ.

(Invited) Challenges for Accelerating Life Testing of Commercial Lithium-Ion Batteries

Life testing of commercial lithium-ion batteries is critical for predicting lifetime, anticipating failure, and guaranteeing safe operation of real-world battery energy storage systems. The traditional method for conducting life testing is to use accelerated aging experiments, where stress factors such as temperature, charge/discharge rate, or daily charge-throughput are pushed to extremes to drive cell failure, while taking care not to induce degradation mechanisms that do not reflect real-world use. But even ‘accelerated’ aging tests generally require 6 months to several years of testing to reach end-of-life for the current generation of mass-produced lithium-ion batteries. So, many efforts have been made to accelerate ‘accelerated aging’ of commercial cells throughout the battery community. But it is critical to ensure that the results of invasive or novel accelerated life testing experiments match well with not only changes to the electrochemical performance of traditionally aged cells, but also that the impacts of physical or chemical degradation mechanisms are also well characterized.This work compares the results of a 2-year accelerated aging test conducted on 23 commercial large-format NMC-Gr cells with a variety of other accelerated life testing experiments. Coin-cell experiments using both full-cell and symmetric-cell configurations were used to study the microstructural changes and electrochemical behavior of both NMC and graphite electrodes, with the small format allowing for destructive characterization of many test replicates throughout cell lifetime; these experiments can be conducted more quickly than their large-format counterparts, and enable more detailed understanding of the degradation trajectory than the large-format test. However, difficulties in transferring electrochemical trends from the coin-cell format to the large-format cell will be discussed. In addition, cascading failure mechanisms observed in the large-format cells may not occur in coin-cells due to differences in the mechanical and thermal environment of each system. Implications for the design of small-format accelerated life testing using electrodes harvested from commercial batteries will be discussed. Calendar aging was accelerated by monitoring daily self-discharge and quantifying both reversible and irreversible capacity losses; challenges for making quantitative predictions from short-term calendar aging tests will be presented.

Evaluating the Effects of RA on the Rheological Properties and Aging Susceptibility of RAM Asphalt

Recycling agents (RAs) can mitigate the adverse effects of reclaimed asphalt pavement (RAP) on recycled asphalt, which can result in more RAP being added. To explore the effects of four RAs on recycled asphalt, this study used asphalt rheological performance experiments, including the bending beam rheometer (BBR) test, the dynamic shear rheological (DSR) test, and the indirect tensile asphalt cracking test (IDEAL-CT), to study the performance grade (PG), cracking resistance, and cracking susceptibility of recycled asphalt. In addition, an aging model for asphalt was used, and short-term and long-term aging sensitivities were evaluated according to this model. Results showed that US Soybean significantly enhanced the high-temperature and low-temperature performance grade (PGLT) and cracking resistance and reduced cracking sensitivity of the recycled asphalt. In addition, the short-term aging sensitivity was the lowest. It showed the best regeneration effect. However, the recycled asphalt with US Soybean showed the highest long-term aging sensitivity, suggesting that longer aging time results in poorer performance. Ingevity’s PG, cracking resistance, and cracking sensitivity are slightly lower than that of US Soybean, and Ingevity demonstrated the second lowest short-term aging sensitivity. However, its prolonged aging sensitivity was much lower than that of US Soybean. Asphalt and Wax Innovations and Georgia Pacific agents slightly improved recycled asphalt properties. The long-term aging sensitivity of recycled asphalt with four Ras was higher than that of recycled asphalt without Ras. These results indicated that the recycled asphalt’s performance with Ras worsened as aging time increased compared to the original recycled asphalt.