Recycled Asphalt Shingles Binder Research Articles

Rheological multi-scale evaluation of RAP and RAS binders mobilisation in hot mix asphalt

The use of Reclaimed Asphalt Pavement (RAP) and Recycled Asphalt Shingles (RAS) in asphalt mixes is a constructive solution allowing economic, environmental and technical benefits. The objective here is evaluating the binder mobilisation rate of recycled materials by predicting the viscoelastic (LVE) behaviour of the asphalts from the LVE of their theoretical binder. The multi-scale approach adopted here goes from the binder scale to the mix scale. At the binder scale, after the extraction/recovery of RAP and RAS binders, several bitumen blends were produced and characterised by conventional and rheological tests. At the asphalt scale, the LVE behaviour of several mixes containing RAP and RAS was characterised using complex modulus test. Then, Shift-Homothety-Shift-time-Shift-transformation (SHStS) was applied allowing verifying the correspondence degree between the experimental behaviour and the predicted one. The results confirm that the totality of the RAP binder was mobilised and up to 50% in the case of RAS.

Characterization of asphalt binders extracted from field mixtures containing RAP and/or RAS

The use of reclaimed asphalt pavement (RAP) and/or recycled asphalt shingles (RAS) in the asphalt mixtures is a common practice in the U.S.A. However, there is a controversy to date on how RAP/RAS interact with virgin asphalt binders (VABs) in asphalt mixtures. For mixtures containing RAP/RAS, the aged asphalt binders in RAP and air-blown asphalt binders in RAS alter the performances of the extracted asphalt binders (EABs). Thus, the rheological properties of EABs from these mixtures require more investigation. The focus of this paper was relating the high-temperature properties of EABs from field cores to the corresponding rolling thin film oven aged virgin asphalt binders (RTFO AVABs). Furthermore, a comparison of the effect of RAP and RAS on the high-temperature rheological properties of EABs was another objective. Different asphalt cores were collected from the field within two weeks after the pavement construction process in 2016. These cores represented eight asphalt mixtures with different asphalt binder replacement percentages by RAP, RAS, or both. The asphalt binders were extracted from these mixtures and considered as RTFO AVABs. The high-temperature rheological properties included the temperature sweep and frequency sweep testing and the multiple stress creep recovery testing. The EABs had higher stiffnesses and elasticates than the corresponding RTFO AVABs because of the aged binders in RAP/RAS. The binders in RAP interacted more readily with VABs than RAS binders.

Study of the quantification of recycled binder activity in asphalt mixtures with RAP

Many environmental and economic benefits can be achieved by employing reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) in asphalt mixtures. However, due to the high stiffness and brittleness of recycled materials, cracking issues may arise when utilizing them at high contents. Recycled binder activity is one of the primary factors that influences the performance of recycled asphalt pavements. Recycled binder activity represents the amount of RAP or RAS binder that becomes active at production temperatures for mixing with the virgin binder. Previous studies have indicated that recycled binders are only partially active; however, the majority of state department of transportation’s assume full activity. Designing recycled asphalt mixtures under the assumption of full recycled binder activity may result in mixtures with insufficient binder content and thus increasing the susceptibility for cracking and moisture damage. This paper compares two recycled binder activity quantification methods; the first method quantifies activity using recycled asphalt mixtures of virgin and RAP materials, while the second method uses 100 percent recycled materials. The two methods showed to produce relatively similar recycled binder activity values; however, the use of 100 percent RAP materials showed to be a more promising approach due to its practicality.

Effect of Reclaimed Asphalt Pavement and Recycled Asphalt Shingles on Fracture Tolerance of Asphalt Binders

Abstract Fracture energy density (FED), which is defined as the energy per unit volume required to initiate fracture, is a key property governing the resistance to fracture of asphalt binders. This study evaluated the effect of reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) on virgin binder FED using the binder fracture energy (BFE) test. The objective was to determine whether RAP and RAS can be used with soft virgin binders to achieve satisfactory fracture tolerance. Experimental factors included two RAP sources, two RAS sources (manufacture waste (MW) shingles and tear-off (TO) shingles), and four virgin binders. BFE tests were conducted on blends of virgin and recovered RAP/RAS binders at two binder replacement rates of 15 % and 30 %. Moreover, the Superpave true grade of RAP/RAS binder blends was determined using the dynamic shear rheometer and bending beam rheometer. Results showed that the use of soft virgin binders effectively compensated for the stiffening effect of RAP/RAS in terms of true grade. The addition of RAP binder and MW shingle binder increased the FED of unmodified binders, whereas the opposite trend was observed for TO shingle binder. Furthermore, great caution should be exercised when using virgin polymer-modified binders because significant reductions in FED were observed when RAP and RAS binder was introduced, possibly because of the dilution of polymer modification in addition to stiffening and embrittlement effects. This study indicated that both RAP and RAS are recyclable, according to the Superpave true grade requirements. However, further research is needed to evaluate the effect of the reduction in binder FED caused by TO shingles on mixture fracture performance before its acceptance in asphalt mixtures.

Laboratory designed hot mix asphalt mixtures with post-consumer Recycled Asphalt Shingles (RAS) utilizing AASHTO PP78

Historically, many state Departments of Transportation (DOTs) do not allow the use of post-consumer Recycled Asphalt Shingles (RAS) due to the high probability that they would be contaminated with asbestos. This study evaluates the performance of hot mix asphalt designed with post-consumer waste RAS provided by local supplier in Bethlehem, PA. Many construction debris recycling plants have a method to ensure their processed post-consumer shingles do not contain asbestos, making it a viable material for inclusion into asphalt pavements. AASHTO PP78, Standard Practice for Design Considerations When Using Reclaimed Asphalt Shingles (RAS) in Asphalt Mixtures, was used in the study in order to design the asphalt mixtures containing the RAS addition. This design method was developed to take into consideration the stiffness of the RAS asphalt binder to help reduce the potential for fatigue cracking. The results of the testing regiment provide guidance to local, state, and federal agencies as to the impacts of including RAS into asphalt pavements and whether to allow post-consumer waste RAS in HMA.However, the issue with utilizing this type of “substitution” specification is that it does not take into the account the quality of the asphalt binder of the RAS. AASHTO PP 78 evaluates the quality of the RAS binder, blended with the virgin asphalt binder, by recommending the solvent recovery of the RAS asphalt binder, blending it with the virgin asphalt binder at varying percentages, and then determining the asphalt binder properties – in particular the influence on the PG grade and the difference in the low temperature critical cracking temperatures (ΔTC).

A Mechanical Approach to Quantify Blending of Aged Binder from Recycled Materials in New Hot Mix Asphalt Mixtures

In the paving industry, there is increased interest in using recycled materials like recycled asphalt shingles (RAS) and reclaimed asphalt pavements (RAP) due to the valuable asphalt binder contained within them. The major concern with using these materials is that the binder they contain is highly aged, which could lead to reduced mixture durability. Therefore, a method is needed to quantify the extent to which the aged binders from these materials blend with virgin binder when producing mixtures in order to understand better their effects on mixture performance. In this study, a new approach to quantify the amount of blending that occurs between aged RAS and RAP binders and a virgin binder was developed. Asphalt binders were extracted and recovered from RAS and RAP stockpiles and blended with a PG64-28 virgin binder in varying proportions. The master curves of these mixtures were constructed at 20°C. Asphalt mixtures containing different proportions of the same RAS and RAP stockpiles were then designed and the dynamic moduli of the mixtures were measured to construct mixture master curves at 20°C. The binder master curves for each blending proportion were then substituted into a locally calibrated Hirsch model to predict the mixture master curves. Comparison of the measured and predicted mixture master curves suggested that the aged binder from RAS and RAP blends with the virgin binder less than 40% and 60%, respectively. Cracking tests were also conducted to validate the proposed degrees of blending from a mixture mechanical performance point of view.

Multi-scale evaluation of the effect of ras on the fracture properties of asphalt mixtures

A comprehensive laboratory testing program was conducted to examine the blending between recycled asphalt shingles (RAS) and virgin asphalt binders and to evaluate the effect of RAS on resistance of asphalt mixes to fatigue and low-temperature cracking. To this end, atomic force microscopy (AFM) was utilized to study the blending between the RAS and the virgin asphalt binders. Manufacturing waste RAS and tear-off RAS were used in this paper. A new sample-preparation procedure was developed to simulate the blending between the RAS and the virgin asphalt binders that occurs during the asphalt mixture production. The stiffness and the adhesive properties were evaluated along the blending zone between the RAS and virgin binders. Several asphalt mixtures were also used to evaluate the effect of the incorporation of RAS on the mix performance, including a control mixture with virgin materials only, and two mixtures containing 5% RAS materials. The resistance of the asphalt mixtures to fatigue cracking was evaluated using the semi-circular bend (SCB) test. In addition the potential for low-temperature cracking was evaluated using the asphalt concrete cracking device (ACCD). The AFM test results showed that very limited to no blending between manufacturing waste or tear-off RAS materials and the virgin binder considered. The asphalt mixture test results also showed that the use of tear-off RAS in asphalt mixes significantly reduced their resistance to low-temperature and fatigue cracking, which can be attributed to the very limited blending observed in the AFM experiments between the RAS and the virgin asphalt binders.

Performance evaluation of plant-produced warm mix asphalts containing RAP and RAS

In the present study, rutting performance, cracking resistance, and durability of five plant-produced asphalt mixes containing 12% reclaimed asphalt pavement (RAP) and 3% recycled asphalt shingles (RAS) and produced with different warm mix asphalt (WMA) technologies were evaluated through characterisation of extracted asphalt binder and performance tests conducted on asphalt mix specimens. For all of the extracted and recovered asphalt binders, continuous grades and difference between critical low temperatures, ΔTcr parameter, were determined from performance grading and a Glover–Rowe (G–R) damage zone was evaluated at 45°C and 10 rad/s. It was revealed that the application of a rejuvenating agent (RA) significantly reduced high PG grade of the overall asphalt binder. The binder test results also indicated that the chemical-additive-based WMA technology had an advantage over the foaming-based technology in terms of asphalt binder durability. Furthermore, the application of RA improved the asphalt binder durability. Comparison of G–R parameters of the recovered asphalt binders showed that using RA and lowering virgin binder high PG true grade improve the overall binder ductility and damage resistance. Asphalt mix performance tests included dynamic modulus (DM), flow number, and semi-circular bend. The DM test data indicated that the application of RA and lowering the virgin binder high PG grade lowered the mix stiffness at low frequencies. Comparison of the methods to compensate the effect of highly aged RAP and RAS binders indicated that the mix prepared with RA and one level high PG grade drop performed better than the mix prepared by dropping the PG grade by two levels in terms of cracking resistance and rutting performance. The findings give credence to utilisation of RAs and softer virgin binders in balanced RAP/RAS mix design approaches.

Proposing a solvent-free approach to evaluate the properties of blended binders in asphalt mixes containing high quantities of reclaimed asphalt pavement and recycled asphalt shingles

Traditionally, the properties of blended binders in asphalt mixes containing reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) are evaluated through rheological testing of the binder extracted and recovered from a mix. However, this approach has long been criticized for being labor intensive, for potentially altering the chemistry of the binder and consequently changing the binder rheology, for forcing blending of binders that may not have been present in the mix, and for creating hazardous material disposal issues. The research presented in this paper proposes an alternative approach for characterizing blended binders by testing the linear viscoelastic properties of a fine aggregate matrix (FAM) asphalt mix using a torsion bar fixture in a dynamic shear rheometer (DSR). A procedure has been developed for preparation and testing of these FAM specimens. Based on the results from this preliminary study, FAM testing is considered to be an effective alternative approach to chemical binder extraction for characterizing the properties of blended binders, compatibility of virgin binders with RAP and RAS binders, and the influence of rejuvenating agents.

Effect of Rejuvenators on Rheological, Chemical, and Aging Properties of Asphalt Binders Containing Recycled Binders

The use of reclaimed asphalt pavements (RAP) and recycled asphalt shingles (RAS) in pavements has already become a norm in the United States because of the substantial reduction in construction cost, energy consumption, and greenhouse gas emissions. However, highway agencies are still reluctant to increase the overall percentage of RAP and RAS in asphalt pavement mixtures because of a higher potential of premature cracking in these pavements. To avoid early pavement failures and untoward maintenance cost, rejuvenators are being increasingly used in asphalt mixtures to reconstruct the chemical structures of oxidized RAP and RAS binders. However, the overall effects of rejuvenators on the properties of asphalt binders have not been well studied in recent years and used in determining the optimum dosages for different rejuvenators. This study characterizes the effects of rejuvenators on the rheological, chemical, aging, rutting, and cracking properties of asphalt binders containing recycled binders and then uses the findings to recommend optimum dosages. To that end, PG 64-22 virgin binders were blended with different types of rejuvenators and recycled binders at various concentrations. Laboratory test results showed that rejuvenators could reduce the stiffness, oxidation, and cracking potential of these blends. Results also suggested that selecting the rejuvenator dosage and type on the basis of only one criterion could not meet the specifications of traditional virgin binders. In addition, the results showed that different rejuvenators worked differently with different mixtures.

Quantitative Characterization of Binder Blending

The current tendency in the asphalt paving industry is to increase the use of recycled asphalt pavement (RAP) and recycled asphalt shingles (RAS). However, a major concern that limits the use of RAP or RAS is the uncertainty about how much of the aged binder in RAP or RAS can be blended into virgin binder. Studies have focused on the diffusion between old and new binders. However, little research has been conducted to determine how much recycled binder could be mobilized and made available to coat aggregates. This study developed a laboratory procedure to quantify the rate at which aged binder was mobilized for recycled mixtures containing up to 80% RAP and 10% RAS. A new term, “large molecular size percentage (LMSP),” was derived from gel permeation chromatography testing and used to characterize recycled and virgin binders as well as their blends. Blending charts were generated for virgin–aged binder blends containing 0% to 100% RAP or RAS binder in LMSP. The relationship was found to be linear between LMSP and RAP or RAS binder content. An experiment was conducted to validate the method proposed for determining the mobilization rate. The results showed that the RAP binder mobilization rate decreased with the increase in RAP percentage in the mixture, which could be close to 100% at low RAP contents (10% and 20%); the rate dropped from 73% to 24% when the RAP percentage increased from 30% to 80%. For RAS, the mobilization rate reached a peak at 5% RAS content and then started to decrease with the increase in RAS content.

Characteristics of Virgin and Recycled Asphalt Shingle Binder Blends

Application of recycled asphalt shingles (RAS) into hot-mix asphalt have been well accepted by many transportation agencies in recent years. However, limited information on virgin-RAS binder blends is available. This study focused on the rheological and chemical characteristics of different blends. Two virgin binders (PG 64-22A and PG 64-22B) and three RAS binders (original RAS binder, extracted RAS binders from tear-off, and manufacture waste asphalt shingles) were used. Different from the well-known linear blending of virgin and reclaimed asphalt pavement binders, the virgin and RAS binder blending followed a nonlinear trend. The nonlinear behavior was found to relate closely to the asphaltene content of the virgin and RAS blends. Furthermore, the identified nonlinear behavior could be described by a simple linear equation because the normalized increase in high-temperature performance grade varied linearly with the increase in the RAS binder content. The Christensen–Anderson (CA) model and the Williams–Landel–Ferry (WLF) shifting equation successfully described the complex shear modulus behavior of different blends of virgin and RAS binders. The results also showed that adding RAS binders to virgin binders had a similar impact as that of aging on rheological parameters such as the rheological index, crossover frequency, and WLF parameters. The addition of RAS binder reduced the temperature susceptibility of virgin binders. In addition, the study found that the carbonyl area measured with a Fourier transform infrared-attenuated total reflectance spectroscopy was highly related to the CA model and the WLF shifting parameters.

Characterizing Rheological Properties of Binder and Blending Efficiency of Asphalt Paving Mixtures Containing RAS through GPC

AbstractUse of recycled asphalt shingles (RAS) into asphalt mixture has become more popular in asphalt paving industry due to dwindling natural resources and potential economic benefits. However, one critical question arises as to how much of aged asphalt binder in RAS can be effectively blended with virgin binder during mixing and construction. This paper presents a laboratory study in which gel permeation chromatography (GPC) was used to determine the blending efficiency of RAS. A correlation was first established between percentages of large molecules (LMS) obtained from GPC and rheological properties of RAS binders. Then the relationship was used to estimate the blending efficiency of RAS binders. The effects of aggregate size, RAS content, and mixing time on blending efficiency were evaluated. The test results show that the percentage of LMS was highly correlated with the complex shear modulus (G*) of asphalt binder. Increasing mixing time led to a better blending of RAS mixture. Aggregate size did n...

Variability and Characteristics of Recycled Asphalt Shingles Sampled from Different Sources

While the recycling of asphalt shingles is beneficial in reducing the consumption of virgin materials, pavement performance should not be compromised. One major concern with recycled asphalt shingles (RAS) relates to the variability in the properties of the recycled materials originating from different sources. In addition, the rheological properties of RAS have not been evaluated as well as its influence on the virgin binder when used in asphalt mixtures. Therefore, the objectives of this study were to characterize the rheological properties and molecular fractions of RAS materials sampled from different sources around the country. In addition, the influence of RAS on the Superpave Performance Grade (PG) of the binder was investigated. Results of the experimental program indicated that the asphalt cement (AC) content in tear-off shingles was consistent among different RAS sources across the country. However, AC content in manufacturer waste shingles was noticeably lower than in tear-off shingles. In addition, all extracted RAS binders were graded as PG 118 or higher using the Superpave binder specification system but the low temperature grade was not measurable due to the high stiffness of the binder. This stiff behavior is due to the binder used in shingle manufacturing, which is an air-blown asphalt binder with stiff characteristics and low elongation properties. Results showed that at a RAS content of up to 5%, the high temperature grade of the blends was increased by one to seven grades and the low temperature grade was increased by one grade. The use of binder blending charts is recommended to account for the influence of RAS in the mix design. At a RAS content of 10%, the binder blends did not pass the Superpave criterion at low temperature.

Effect of recycled asphalt shingles on physical and chemical properties of virgin asphalt binders

A laboratory study was conducted to evaluate the effect of recycled asphalt shingles (RAS) on the physical and chemical properties of virgin asphalt binders. A virgin asphalt binder meeting the Superpave specifications for PG 58-28 was mixed with varying percentages (0%, 5%, 7%, and 10%) of RAS binder recovered from post-manufactured asphalt shingles. The physical properties of the blended binders were measured using the rotational viscometer (RV), dynamic shear rheometer (DSR), multiple stress creep recovery (MSCR), and bending beam rheometer (BBR) tests. The chemical properties of the binders were determined using the Fourier transform infrared spectrometry (FTIR) and gel-permeation chromatography (GPC) tests. The physical test results showed an improved resistance to permanent deformation (or rutting) with the addition of RAS, but higher susceptibility to early low-temperature (thermal) cracking. The results were inconclusive regarding the fatigue resistance of the RAS-containing asphalt binders. The chemical test results showed an increased level of aging due to the addition of RAS. Higher levels of aging were also observed following the use of the rolling thin film oven (RTFO) and the pressure aging vessel (PAV) tests. There was a modest increase in the level of aging in RTFO-aged binders due to the addition of RAS. However, significantly higher levels of aging were obtained for PAV-aged binders containing higher percentages of RAS, indicating that the addition of RAS will primarily impact the long-term performance of the asphalt binders.

Recycled Asphalt Shingle Binder Characterization and Blending with Virgin Binders

In addition to reclaimed asphalt pavement (RAP), recycled asphalt shingles (RAS) have been accepted and used by different transportation agencies in recent years. However, limited information on RAS binder characterization and blending with virgin (and RAP) binders is available in the literature partially because of the limitations of regular dynamic shear rheometers (DSRs) and bending beam rheometers (BBRs) to test this type of material. This paper first validated the applicability of the existing asphalt binder extraction and recovery procedures to extremely stiff RAS binders. Then a variety of tear-off asphalt shingles (TOAS) and manufacture waste asphalt shingles (MWAS) were extracted, recovered, and characterized with a high-temperature DSR and a BBR. It was found that TOAS binders were much stiffer than MWAS binders. Furthermore, this paper investigated the blending among virgin, RAP, and RAS binders. The results indicated that the virgin–RAS binder blending was nonlinear, unlike the well-known virgin–RAP binder linear blending. However, for practical application, the linear blending chart can still be used for estimating continuous grades of both virgin–RAS blended binders and virgin–RAP–RAS blended binders if the RAS binder is limited to 30% of the total binder. Additionally, compared with TOAS binders, MWAS binders had much less impact on properties of blended virgin–RAS binders. Therefore, it was necessary to differentiate MWAS from TOAS in the mix design process and to have different upper limits on maximum RAS binder replacement for MWAS and TOAS.

Performance Characterization of Asphalt Mixtures at High Asphalt Binder Replacement with Recycled Asphalt Shingles

Recycled materials can be used effectively in asphalt mixtures to replace virgin asphalt binder or virgin aggregates. Virgin material (asphalt binder or aggregate) can be replaced with reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) in asphalt mixtures. The study presented in this paper examined the effect of high asphalt binder replacement (ABR) for an asphalt mixture with a low number of design gyrations (a low N-design) and RAP and RAS on performance indicators (e.g., permanent deformation, fracture, fatigue potentials, stiffness). A developed experimental program included complex modulus, fracture, overlay reflective cracking resistance, low-temperature cracking, wheel track permanent deformations, and push–pull fatigue tests. The ABR, combinations of RAS and RAP asphalt binder, and levels in the mix ranged from 43% to 64%. Potential permanent deformation resistance of the mixtures was improved in the presence of RAS. Fracture tests at low temperature revealed no significant difference between the specimens prepared at varying percentages of ABR. Fatigue potential of mixtures increased with an increase in RAS content and ABR. The specimens prepared with 2.5% RAS and PG 46-34 showed the best fatigue potential performance. The impact of asphalt binder bumping was highlighted by the results of all tests. The improvement in fatigue life and fracture energy was noticeable when the asphalt binder type was changed from PG 58-28 to PG 46-34 at the highest ABR level. The complex modulus test results can provide crucial information about the mix viscoelastic properties, such as relaxation potential and long-term stiffness. These results can be used, along with fracture test results, to evaluate mix brittleness at relatively high ABR levels.

New Approach to Recycling Asphalt Shingles in Hot-Mix Asphalt

The objective of this study is to introduce a new approach to recycling asphalt shingles in asphalt paving construction in which recycled asphalt shingles (RAS) are ground to ultrafine particle sizes and blended with asphalt binder through a wet process. In the proposed wet process, the ground recycled material is blended with the binder at a high temperature prior to mixing with the aggregates. Two unmodified binders that are classified as PG 64-22 and PG 52-28 were blended with two contrasting sources of RAS at a modification content ranging from 10–40% by weight of the binder. The use of RAS modification through the proposed wet process was successful in the laboratory. Based on the results of the experimental program, the use of RAS modification through the proposed wet process would generally improve or not influence the high temperature grade of the binder, but it may reduce the low temperature grade of the binder. As demonstrated in this study, an optimum shingle content may be identified that will improve the high temperature grade without influencing the low temperature grade of the binder. Using confocal laser-scanning microscopy (CLSM), wax crystals ranging from 4–8 μm in size were successfully detected. However, wax crystals were not detected in the RAS-modified binder, which may indicate that the wax molecules are absorbed by the RAS material. Results of high-pressure gel permeation chromatography (HP-GPC) showed that the proposed wet method of modification produced a slight increase in the high molecular weight (HMW) (>3,000 daltons) content in the prepared blends at higher RAS contents, suggesting that a fraction of the RAS binder contributes to the blend properties.

Estimating the Effect of Recycled Asphalt Pavements and Asphalt Shingles on Fresh Binder, Low-Temperature Properties without Extraction and Recovery

The use of recycled asphalt pavements (RAP) and recycled asphalt shingles (RAS) as components of new asphalt mixes is expected to reduce construction costs, protect the environment, and conserve dwindling natural resources. However, the use of high percentages of RAP and RAS requires mix adjustments to accommodate the stiffer binder, which in turn requires quantification of the effect of the RAP and RAS binder on the fresh binder used in the mixture. Current methods for such estimates are performed on the basis of either chemical extraction and recovery of the binder or backcalculation from gyratory compacted samples. The former is not desirable because of the unknown effects of the chemical solvents on the binder, and the latter requires extensive laboratory work and resources. This paper modifies the analysis procedure for estimating the low-temperature properties of RAP binder by means of testing mortars and binders in the recently developed bending beam rheometer. The modified testing procedure was verified by testing artificial RAP materials, and found capable of estimating low-temperature grade of aged binder within 1°C of the known grade. Furthermore, the application of the procedure to RAS allowed for the introduction of the basis for the development of RAP and RAS blending charts to estimate the final grade of blended binder in mixtures. The feasibility of extending the procedure to study the effect of RAP and RAS on binder fracture properties is also presented in this paper.