Warm Mix Asphalt Technology Research Articles

Rutting characteristics evaluation and prediction model development for warm mix asphalt

ABSTRACT The warm mix asphalt (WMA) technology has brought environmental sustainability into the pavement industry with its preparation at lower production temperatures than hot mix asphalt (HMA). Nevertheless, it has also raised concerns regarding the mixture’s resistance to permanent deformation as a result of its reduced aging during production. This study examines the effects of warm mix modification on the rutting potential of bituminous mixes. Two modifiers were used for WMA preparation – polyethylene wax (PEW) and waste cooking oil (WCO). Binder rutting properties were evaluated using the multiple stress creep recovery (MSCR) test. Subsequently, WMA mixtures were prepared at adequate production temperatures, and then their rutting characteristics were evaluated using the Cooper wheel tracker device. The study concluded that introducing warm mix modifiers in small amounts, approximately 1–2% by weight of bitumen, results in rutting characteristics comparable to virgin bituminous mix, whereas the characteristics deteriorate at higher modifier contents. Furthermore, a rutting prediction model based on the Weibull failure rate function (WFRF) was developed. A strong correlation was found between the measured wheel tracking data and the prediction model in all mixtures. PEW was discovered to be a superior warm mix modifier to WCO in terms of rutting resistance.

Optimizing the Dose of Warm-Mix Asphalt Additives by Maximizing the Asphalt-Aggregate Adhesion Measured via Surface-Free Energy

Warm-mix asphalt (WMA) is a group of technologies focused on reducing the viscosity of the asphalt binder (or binder) to produce asphalt mixtures at a reduced temperature compared with that specified for conventional hot-mix asphalt mixtures. The WMA technologies include two main groups: foaming and additives. The additives can be classified as synthetic-chemical or natural-based. This study aims at assessing the feasibility of optimizing the WMA additives dose by maximizing the adhesion between the asphalt binder and the aggregate at their interface in WMA mixtures. Adhesion is quantified using energy parameters derived from surface-free energy measurements (SFE), including three WMA additives (Carnauba wax, a natural-based warm-mix additive, Sasobit, and Evotherm). Accomplishing this objective required measurements of SFE for four different asphalt binders, and corresponding WMA-modified asphalt binders were performed. The results suggest the possibility of identifying a WMA-additive dose that maximizes adhesion at the binder–aggregate interface in terms of resistance to fracture (i.e., adhesive failure) and moisture damage, and the wettability of the binder. In addition, the results showed that the inclusion of Carnauba wax as a warm-mix additive yielded equivalent adhesion at the binder–aggregate interface compared with the response of the other commercially available WMA additives evaluated (i.e., Sasobit and Evotherm). Additional studies at the mixture level are recommended to validate further the conclusions obtained in this study.

Exploring the consequences of reduced aging on the performance of warm mix asphalt binders

ABSTRACT Warm mix asphalt (WMA) technology has proven to be a viable alternative to asphalt pavement production due to its lower mixing and compaction temperatures. However, the performance of asphalt binders is a concern linked to WMA technology due to its reduced aging effect. This study investigates the impact of redcued aging temperature on the performance of two different WMA additives blended with VG30 binder. Fourier transform infrared spectroscopy (FTIR) was performed to check changes in chemical composition of asphalt binder due to aging. Performance of the WM modified asphalt binders was assessed using linear amplitude sweep (LAS), multiple stress creep and recovery (MSCR), and bitumen bond strength (BBS) tests. FTIR analysis showed that used WMA additives increases the aging resistance of asphalt binder. Test results revealed that the application of Rediset enhanced the fatigue performance compared to neat and Sasobit modified asphalt binder. On the other hand, Sasobit decreased the non-recoverable creep compliance (Jnr) and increased the percent recovery (%R), whereas the contrary trend was observed with the addition of Rediset. It was found that Rediset exhibits the antistripping properties thereby improving the bond between asphalt binder and the aggregate, even at reduced production temperature.

Optimization of asphalt mixture design using response surface method for stone matrix warm mix asphalt incorporating crumb rubber modified binder

The use of crumb rubber as an asphalt bitumen performance improver has received special attention. The high viscosity of crumb rubber modified binder (CRMB) and the need for high production temperatures in mixtures containing this type of bitumen necessitate the use of warm mix asphalt (WMA) technology. One of the important applications of CRMB is in special-use mixtures such as stone matrix asphalt (SMA). This study aimed to determine the optimal design of stone matrix warm mix asphalt containing CRMB. Therefore, the response surface method (RSM) was used to develop the response prediction models. Production temperature and the content of polyethylene wax and CRMB were considered independent variables of the study. Moisture sensitivity, flow number, resilient modulus, and critical stress intensity factor were used as response (dependent) variables to determine the optimal design of the mixture. The results showed that the prediction models of response variables can predict the performance results with acceptable accuracy. Production temperature and polyethylene wax content are the most important factors in prediction models. To achieve the optimal design of the mixture, minimizing the production temperature and resilient modulus and maximizing the flow number, resistance to moisture susceptibility, and critical stress intensity factor led to the achievement of desirable solutions. The optimal design of stone matrix warm mix asphalt containing CRMB at 135 °C, 7.02 % CRMB, and 2.1 % polyethylene wax using predictive models with 0.765 desirability were obtained.

Prediction of the Long-Term Performance of an Existing Warm Recycled Motorway Pavement.

Warm mix asphalt (WMA) technologies allow the production, lay-down and compaction of asphalt mixtures at reduced temperatures and the use of higher amounts of reclaimed asphalt pavement (RAP) with respect to conventional hot mix asphalt (HMA), leading to significant environmental benefits and energy savings. However, limited data is available on the long-term performance of such pavements. The objective of this study was to predict the long-term performance of an existing warm recycled motorway pavement (made with WMA mixtures containing RAP) constructed in 2016 in central Italy, along with the corresponding hot recycled pavement (made with HMA mixtures containing RAP). For this purpose, cores were taken from the pavements in 2022 to investigate the binder and base courses through dynamic modulus and cyclic fatigue tests, according to the simplified viscoelastic continuum damage (S-VECD) testing approach. The results of the tests were used to predict the service life of the pavements using two pieces of software, KENPAVE and FlexPAVE, based respectively on the elastic design method and the viscoelastic design method in the presence of damage. The FlexPAVE results indicated that the expected service life of the WMA pavement is much longer than that of the HMA pavement, mainly because the WMA mixtures have better damage properties than the HMA mixtures. Conversely, the KENPAVE simulations predicted a similar service life for the two pavements, highlighting the impossibility of the elastic method to catch the actual contribution of high-performance non-standard materials. The promising outcomes of the FlexPAVE simulations further encourage the application of warm recycled pavements.

A Study on Indirect Tensile Strength for the Determination of Resilient Modulus of Warm Mix Asphalt

The advent of Warm Mix Asphalt (WMA) incorporating Recycled Asphalt Pavement (RAP) as a long-term solution to partially or totally participate in remediating the problem of global warming and the regression of environmental resources has been expanding and gaining interest throughout the world. The WMA-RAP technology created as an improved WMA technology has shown to possess mechanical properties closely similar to Hot Mix Asphalt (HMA). Though searching for environmentally sustainable asphalt technologies have become vital, the quest to construct economically sustainable highways cannot be neglected. The dynamic modulus tests (DMT) is among the most accurate yet expensive laboratory tests performed to determine the resilient modulus of asphalt mixes. Therefore, this paper aims to determine the resilient modulus of asphalt mixes (WMA-RAP and HMA) through both the indirect tensile strength (ITS) and the correlation formula method (CFM) and compares them against the dynamic modulus tests method (DMTM). Furthermore, this study utilises the resilient modulus found through CFM and DMTM to predict and compare the mechanical performances of asphalt pavement systems. Finite Element Modelling (FEM) and Linear Elastic Analysis (LEA) were used to modelling and analysing the mechanical behaviour of pavement systems. Both the WMA15% RAP and WMA30% RAP samples were mixed with 50/70 grade bitumen modified with Sasobit additive. The HMA samples on the other hand were mixed with non-modified 50/70 grade bitumen. Findings show that the resilient moduli of HMA and WMA-RAP mixes obtained through CFM is 77% close to the DMTM. In addition, the HMA and the WMA-RAP pavements with CFM and DMTM resilient moduli also show very close mechanical performance. This signifies that the CFM can be used as a reliable and cost effective alternative method to determine the resilient modulus of asphalt mixes.

Use of Multi-Scale Investigation to Evaluate Adhesion Performance of Warm-Mix Polymer-Modified Asphalt

Warm Mix Asphalt (WMA) technology can effectively reduce carbon emissions and energy consumption during road project construction. However, it may have a negative impact on the binding properties of asphalt mixtures. In order to effectively evaluate the adhesion performance of asphalt binders and aggregates under the combined influence of WMA and traditional polymer-modified asphalt, this paper provides a comprehensive evaluation at the micro and macro levels. The adhesion between three different modified asphalts (warm mix crumb rubber/ Styrene-Butadiene-Styrene (SBS) composite modified asphalt, warm mix crumb rubber asphalt, and warm mix SBS modified asphalt) and two different aggregates (limestone and granite) under both virgin and short-term aging conditions were analyzed. Regardless of the type of modified asphalt, the results showed that limestone aggregates have better adhesion properties with asphalt binders. In addition, the short-term thermal oxidation aging behavior is conducive to enhancing the asphalt-aggregate adhesion characteristics. Furthermore, WMA additives, crumb rubber, and SBS compound modification can improve the adhesion performance between asphalt and aggregate.

Strategy for improving the effect of hot in-place recycling of asphalt pavement

The material composition of hot in-place recycling asphalt mixture (HIRAM) fluctuates violently during construction in the field, effecting the hot in-place recycling (HIR) construction quality. In addition, construction cost optimization and carbon emission control are also crucial factors to consider in today's pavement projects. To maximize the benefits of HIR maintenance technology, a systematic procedure for designing the HIRAM material composition and a strategy for optimizing the construction parameters are proposed by considering the RAP variability, construction costs, and carbon emissions. The management strategy for controlling the construction quality of HIR in the field is also proposed, and the feasibility of the strategy for designing HIRAM material composition and optimizing the construction parameters is verified in engineering practice. The results show that there is a significant difference in RAP material composition at different road sections, and the procedure developed in this study can precisely design the HIRAM material composition based on the principle of similarity of RAP aggregate gradation via Fréchet similarity and K-means cluster analysis, and the accuracy of HIRAM gradation design can be improved to 26.5 %. The HIR construction parameters can be optimized by applying the warm mix asphalt technology based on the multi-objective optimization model. At the same time, the benefits are evaluated, showing that the total construction cost and CO2 emissions of the project can be reduced by 6.67 % and 16.81 %, respectively. Those working in the field of asphalt pavement maintenance may be interested in this strategy, as this study was done intentionally for practical applications.

Evaluation of the field-aged performance of foamed warm mix asphalt: Comparisons with hot mix asphalt

The foamed warm mix asphalt (FWMA) has been widely used as a sustainable construction technique in pavement engineering, yet has not yet been fully studied for its aging performance or durability. Here we aim to examine and evaluate the performance variation characteristic of FWMA compared with conventional hot mix asphalt (HMA) under long-term service conditions. The performance evolution of FWMA core samples drilled from four highways was compared to that of ordinary HMA, which was simultaneously constructed. Fourier transform infrared (FTIR), dynamic shear rheology (DSR), and bending beam rheometer (BBR) tests were respectively performed to evaluate the aging degree, high-temperature, and low-temperature rheological characteristics. The results demonstrated that the aging resistance of foamed WMA was slightly diminished under construction conditions with no temperature reduction. With increased service time, the rheological characteristics of FWMA were enhanced at high temperatures, while deteriorated at low temperatures. The foaming water and service time were primary determinants of the aging as well as high and low-temperature rheological properties of FWMA without temperature construction reduction. Additionally, the aging degree of FWMA under short-term and long-term service was smaller than HMA when the construction temperature decreased. The rheological characteristics of FWMA were inferior to those of HMA during both short-term and long-term service stages. Under conditions of temperature reduction, foaming water and mixing temperature exhibited a considerable influence on the aging and rheological properties of FWMA at high and low temperatures. Therefore, the amount of water used for foaming and the temperature of production should be strictly control in the foamed warm mix asphalt technology.

A Comparative Review of Hot and Warm Mix Asphalt Technologies from Environmental and Economic Perspectives: Towards a Sustainable Asphalt Pavement.

The environmental concerns of global warming and energy consumption are among the most severe issues and challenges facing human beings worldwide. Due to the relatively higher predicted temperatures (150-180 °C), the latest research on pavement energy consumption and carbon dioxide (CO2) emission assessment mentioned contributing to higher environmental burdens such as air pollution and global warming. However, warm-mix asphalt (WMA) was introduced by pavement researchers and the road construction industry instead of hot-mix asphalt (HMA) to reduce these environmental problems. This study aims to provide a comparative overview of WMA and HMA from environmental and economic perspectives in order to highlight the challenges, motivations, and research gaps in using WMA technology compared to HMA. It was discovered that the lower production temperature of WMA could significantly reduce the emissions of gases and fumes and thus reduce global warming. The lower production temperature also provides a healthy work environment and reduces exposure to fumes. Replacing HMA with WMA can reduce production costs because of the 20-75% lower energy consumption in WMA production. It was also released that the reduction in energy consumption is dependent on the fuel type, energy source, material heat capacity, moisture content, and production temperature. Other benefits of using WMA are enhanced asphalt mixture workability and compaction because the additives in WMA reduce asphalt binder viscosity. It also allows for the incorporation of more waste materials, such as reclaimed asphalt pavement (RAP). However, future studies are recommended on the possibility of using renewable, environmentally friendly, and cost-effective materials such as biomaterials as an alternative to conventional WMA-additives for more sustainable and green asphalt pavements.

Effect of warm mix asphalt additive on the workability of asphalt mixture: From particle perspective

Warm mix asphalt (WMA) technologies, in recent decades, have gained much popularity given their proven benefits of improved workability, reduced energy consumption, and improved sustainability. However, how to select a WMA technology and determine its effectiveness at a required condition is still a question. Most current works focus on the binder’s rheological properties. Very few have investigated the particles’ behaviors during compaction, which should have a direct correlation with the mixture’s workability. With the development of a particle-size Microelectromechanical System (MEMS) sensor, SmartRock, this paper aims to analyze the particle’s kinematic behavior during compaction and explore its relationship with the mixture’s workability. With this motivation, 5 asphalt mixtures varying in the production temperature and the dose rate of the chemical additive are prepared and compacted in this study. To focus on the methodology, only one chemical additive with several dosage levels is utilized. It is found that particle rotation is a crucial property for compaction and can be used to evaluate the workability of asphalt mixtures. Relative rotation capacity (RRC) and average residual rotation (ARR) are then proposed and used to evaluate the mixture’s workability. It is verified that the higher production temperature and dosage rate of chemical additives can both improve the particle rotation and the mixture’s workability. The effect of temperature and WMA additive on workability improvement is different for the base conditions (i.e., base production temperature and usage of the WMA additive). Overall, the method proposed in this study is promising for evaluating the workability of asphalt mixtures in compaction.

Technical suitability of wet or dry processing of a dense rubberized warm asphalt mixture

Warm mix asphalt (WMA) and crumb rubber modified asphalt in the field of asphalt paving have been demonstrated to be green technologies for producing environmentally friendly pavement. However, limited research has assessed the behaviours of mixtures including both technologies. This study performed research aligned with environmental considerations and sustainability to examine the design and manufacturing of dense asphalt mixtures incorporating a crumb-rubber modifier through a wet or dry process and a specific vegetable additive for WMA technologies. The results indicated that, when rubber is added through a wet process, and a WMA vegetable additive is incorporated, the mixture can be manufactured and compacted at temperatures approximately 25 °C below that of the control mixture, while keeping the mechanical properties within the specifications.

Rheological Behaviour of WMA-Modified Asphalt Binders with Crumb Rubber.

Crumb rubber (CR) is one of the materials most widely used in the road infrastructure industry due to its mechanical and environmental benefits as an asphalt binder modifier. Nonetheless, CR decreases the workability of mixes by increasing the viscosity of the binder, leading to an increase in the production temperatures of asphalt mixes. However, warm mix technologies can reduce the temperature demand associated with these processes. The preceding explains the growing interest in producing rubberised asphalt binders incorporating warm mix asphalt (WMA) additives. In this research, the mechanical and rheological properties of a 60/70 penetration grade asphalt binder modified with CR (at a dosage of 15, 18 and 21% by the wet process) and WMA chemical additives (Evotherm M1 and Iterlow T) were investigated. Laboratory tests included penetration, softening point, rotational viscosity, frequency sweep through dynamic shear rheometer (DSR), and multiple stress creep recovery (MSCR) tests. The results indicate that CR increases the stiffness of the asphalt binder, which is reflected in a lower penetration grade and improved softening point. It also improves its rutting resistance but decreases fatigue performance. Furthermore, it has been shown that under the conditions studied, the higher the CR content, the more elevated the degree of stiffness and performance of the asphalt binder. On the other hand, WMA technology decreases asphalt stiffness and performance at high temperatures.

Long-term performance assessment of a warm recycled motorway pavement

In the last decade, warm mix asphalt (WMA) technologies have undergone a strong development in the pavement sector. In fact, the reduction of the production and compaction temperatures up to 40 °C with respect to the conventional hot mix asphalt (HMA) mixtures has many environmental beneficial effects. However, the long-term field performance of WMA mixtures is still an open issue, especially when they contain reclaimed asphalt pavement (RAP) and polymer modified bitumen (PMB). In this regard, the objective of this investigation was to monitor the performance of a full-scale field trial constructed along an Italian motorway. The field trial included a section constructed with WMA mixtures (produced with a WMA chemical additive) and a reference section constructed with HMA mixtures. The WMA and HMA mixtures had the same composition (i.e., amount of RAP and PMB) and differed only for the temperatures adopted during the production of the mixtures and construction of the sections. Cored samples were taken from the binder and base courses at different times during the in-service life of the field trial (timespan of six years) and subjected to conventional testing as well as viscoelastic continuum damage (VECD) characterization. The HMA mixtures were generally stiffer than the WMA mixtures, likely due to a more marked RAP oxidation during the production and construction phases and a higher in-service ageing rate. On the contrary, the WMA mixtures always exhibited higher fatigue resistance and better homogeneity than the HMA mixtures. Based on these findings, better long-term performance is expected for the WMA section.

Comparison of moisture susceptibility of Evotherm 3G warm mix asphalt versus hot mix asphalt

Asphalt stripping is a common form of distress caused by moisture that creates a loss of bond between the aggregate and binder. It is thought that the use of warm mix asphalt (WMA) technology could lead to increased moisture susceptibility if the free moisture present in the aggregates does not evaporate at the lower mixing temperatures. The purpose of this study is to evaluate the moisture susceptibility of WMA using Evotherm 3G on laboratory-prepared and plant-prepared mixes. The moisture damage potential was evaluated using the TSR (tensile strength ratio), the static immersion test, moisture-induced stress tester, and Hamburg wheel tracking test. Additionally, plant-prepared mixes were also assessed for TSR and rut depth. The results indicated that WMA provided adequate levels of resistance to moisture damage, reduced swelling, and improved coating. Laboratory mixes showed reduced resistance to rutting, but rut depth of plant mixes was similar to that of hot mix asphalt.

Cracking Resistance of Recycled Rubber Asphalt Binder Composed of Warm-Mix Additives.

Warm-mix asphalt technology has been applied to recycled rubber asphalt binder (RAB), which forms warm-mixed crumb rubber-modified asphalt binder (W-RAB) as a “green” material for environmental conservation and to enhance road performance. Furthermore, low-temperature cracking is one of the major distresses for asphalt pavement, which drastically restricts ride quality and service level. Therefore, the main objective of this study is to comparatively analyze the low-temperature properties of W-RABs based on thermal stress and the simple fractional model. W-RABs were obtained by mixing 60 mesh recycled rubber (CR) and two different types of warm-mix additives, namely viscosity reducer (1, 2, and 3%) and surfactant (0.4, 0.6, and 0.8%). First, Hopkins and Hamming’s numerical algorithm and the Boltzmann superposition principle were used for obtaining thermal stress . Subsequently, critical cracking temperature was derived using the single asymptote procedure (SAP) theory. Second, the simple fractional viscoelasticity model was used to calculate the creep compliance, damping ratio, and dissipation energy ratio, and the results were compared with the Superpave protocol results obtained with bending beam rheometer (BBR) tests. The results showed that a combination of CR and warm-mix additives could slightly improve the thermal crack resistance of the asphalt binder. The addition of 0.6% surfactant yielded the optimum performance, while only a high dosage (3%) of viscosity reducer provided a marked improvement in efficiency, which decreased with a decrease in temperature. This study recommends the use of RAB composited with 0.6% surfactant for areas with extremely low temperature.

Laboratory Evaluation of Warm-Mix Asphalt Open-Graded Friction Courses

This study aimed at evaluating the laboratory performance and physical characteristics of warm-mix asphalt (WMA) open-graded friction course (OGFC) mixes prepared with three warm-mix additives (two chemical additives and an organic additive). To achieve this objective, four mixes were prepared including a control mix (CM) prepared with a PG 76-22 binder and two sources of aggregate (i.e., # 78 limestone and # 67 sandstone). Air voids and coefficient of permeability ( k) were used to evaluate the functionality of the OGFC mixes. In relation to constructability, the compaction energy index was used to compare the required compaction effort during construction. Furthermore, the Cantabro test, Hamburg wheel-tracking test, Texas overlay test, Modified Lottman, and boil tests were conducted to evaluate durability, permanent deformation, cracking, and moisture-damage resistances of the evaluated mixes. Results indicated that the use of WMA technologies enhanced OGFC durability and performance. Among the evaluated mixes, the organic additive-OGFC met all Louisiana Department of Transportation and Development and NCHRP 01-55 requirements, as it notably enhanced OGFC durability, cracking, and moisture-damage resistance. Furthermore, the use of WMA notably reduced the required compaction effort and mixing temperature needed during production and construction as compared with the CM.

Warm Mix Asphalt Demonstration Projects in Louisiana: Case Study of Five to Eight Years of Field Performance

Warm mix asphalt (WMA) technology has gained popularity in recent years because of its ability to enhance mixture compaction at relatively low temperatures and to improve environmental sustainability. The role of WMA in sustainable pavement technology means that there is a need for comprehensive research in relation to its field performance. The objective of this study was to evaluate the field performance of WMA pavement sections that have been in service for five to eight years. Four rehabilitation projects were evaluated throughout the State of Louisiana. The study included field and laboratory experiments. In the field experiment, WMA test sections were evaluated along with companion conventional hot mix asphalt (HMA) mixture sections on each project. Pavement performance indicators (rutting, roughness, and cracking) from the Louisiana Pavement Management System (PMS) were analyzed. The laboratory experiment consisted of evaluation of mixtures from each project to determine mechanical performance indicators such as loaded wheel tracking (LWT) rut depth, flow number, semi-circular bend energy release rate (SCB Jc), and dissipated creep strain energy (DCSE). An analysis was conducted to rank the capability of laboratory mechanical performance properties to predict field performance. Generally, WMA test sections were found to exhibit similar or better rutting and cracking performance compared with their companion control HMA sections. In addition, the LWT rut depth was found to be a better indicator of field rutting performance than the flow number parameter. It is worth noting that the SCB Jc parameter was found to correctly rank more field cracking indicators than the DCSE parameter and therefore it may be a better indicator of field cracking performance.

Engineered nanocomposites in asphalt binders

Abstract Recently, nanotechnology has been effectively used in the field of road pavement. Oxidation and aging of asphalt cause deterioration of road pavements and increase asphalt-related emissions. We propose an anti-aging strategy to interrupt the asphalt deterioration by using engineered clay/fumed silica nanocomposites. In this research, the morphological, chemical, thermal, mechanical, and rheological properties of nano-modified asphalt binders are meticulously analyzed in various conditions. The experiment results proved that this composite efficiently disrupts the chemical oxidation and decomposition in the mixture and reduces the aging rate. Remarkably, asphalt binder rheology experiments revealed that the addition of 0.2–0.3 wt% of nano-reinforced materials maximized their rheological resistance after short- and long-term aging. Moreover, nanoparticles improve the moisture resistance efficiency and in turn overcome the critical issue of moisture in low production temperature within the framework of warm mix asphalt technology. This cost-effective, facile, and scalable approach in warm mix asphalt mixtures can contribute to increased sustainability and lifespan of pavements and a reduction in greenhouse gas emissions.

The Effect of a Chemical Warm Mix Additive on the Self-Healing Capability of Bitumen

Abstract Warm mix asphalt (WMA) technologies reduce the production temperature of hot mix asphalt allowing for mixing and paving at lower temperatures. As a result, the use of WMAs reduces emissions and allows for longer transport times. Because of the recent increase of chemical warm mix additives in industry, the effect of a chemical warm mix additive (cWMA) on the intrinsic self-healing ability of the bitumen was investigated. Bitumen specimens containing three concentrations of cWMA were evaluated at four aging levels (unaged, rolling thin film oven [RTFO]-163°C, RTFO-130°C, and RTFO+ pressure aging vessel [PAV] aged) using the simplified–linear amplitude sweep healing (SLASH) (linear amplitude sweep with a single rest period fatigue-healing) test. Results indicate that oxidative aging of bitumen is reduced with increasing cWMA concentration but may be more heavily influenced by the aging temperature. It was also observed that RTFO+PAV-aged bitumen samples demonstrate greater fatigue restoration ability compared to RTFO and unaged binders. Supplementary work using video-based analysis of dynamic shear rheometer samples revealed that issues may arise from the calibration of the cohesive failure damage level as described in the original LASH procedure because of significant changes in sample geometry observed during the amplitude sweeps for unaged and RTFO-aged material. These results demonstrate that LAS-based healing tests warrant further research to optimize loading and rest period parameters for a wider range of bituminous materials.