Recycled Mixtures Research Articles

Assessment of the Rheological and Mechanical Properties of Emulsion–Cement Paste

The main objective of this study was to evaluate the rheological and mechanical properties of emulsion–cement paste (ECP), which is generally formed during the mixing process of cold recycled mixtures. Forty-five combinations of ECP specimens were prepared at varying amounts of emulsion, cement, and water. Specimens were mixed using a low-shear mixer, then allowed to cure in an oven at 60°C for 72 h. The testing program for ECPs included multiple stress creep recovery, bending beam rheometer, linear amplitude sweep, penetration, and isothermal calorimetry tests. Statistical analyses were then conducted to assess the significance of the impact of ECP constituents on the low-, intermediate-, and high-temperature properties. Results showed that varying the proportions of emulsion, cement, and water significantly influenced the properties of ECPs. Higher cement and water contents improved the properties of ECP at high temperatures, but reduced their resistance to intermediate- and low-temperature cracking. Conversely, increasing the emulsion content improved the resistance of ECPs to fatigue and low-temperature cracking, while increasing their rutting susceptibility at high temperatures. The outcomes of this study provide more knowledge about the interactions among emulsion, cement, and water, which can be beneficial to the designers of asphalt mixtures that involve the use of emulsion, cement, and water, such as cold recycled mixtures.

Early Strength of Cold Recycled Emulsified Asphalt Mixtures

In order to study the influence of different factors on the early strength of the cold recycled emulsified asphalt mixtures, 16 different types of cold recycled mixtures were designed and produced, which were combined with different cement content, water content, and cement-water ratio. The indirect tensile strength (IDT), compressive strength (UCS), tensile strength at 15°C (TS), and indirect tensile strength ratio (ITSR) tests were used to test the early strength of the cold recycled mixture. The variance analysis method was utilized to analyze the influence of the single factor on the early strength of the cold recycled mixture. The results show that appropriate cement-water ratio content can effectively improve the early strength of cold recycled mixtures. According to the Spearman correlation coefficient and comparison of each evaluation indicator, IDT and ITSR are significantly affected by various factors, and the results are relatively stable and well-differentiated, which is recommended as indicators of early strength evaluation. Cement-water ratio is recommended as the main control factor to control the early strength of the cold recycled emulsified asphalt mixtures. The optimal cement-water ratio ranges from 0.6 to 1.0, while the cement content is controlled from 1.2% to 1.5% and the water content from 3.8% to 4.3%. This study is of great significance for promoting the design of emulsified asphalt cold regenerative mixture with cement-water ratio and improving and accelerating its early strength development.

A stress–temperature superposition approach to study the nonlinear resilient behavior of cold recycled mixtures (CRM) with active filler addition

The asphalt paving sector is currently embracing and enhancing cold mixture technologies to reduce carbon emissions and decarbonize its operations. Cold recycled mixtures (CRM) have proven to be a promising alternative in road construction and rehabilitation, becoming a primary research focus. This study evaluates the effects on compactability and volumetric properties of adding 1% Portland cement or 1% hydrated lime to CRM made with 100% reclaimed asphalt pavement and bitumen emulsion. Dynamic triaxial tests with different confinement pressures (ranging from 20 to 200 kPa) and temperatures (5, 15, 25, and 35 °C) were used to determine the influence of these active filler additions on the resilient modulus (Mr) of the mixtures. All the mixtures exhibited increased Mr values at lower temperatures and reduced stress–dependency. Cement addition had the most favorable effect on compactability, reducing the necessary compaction energy, while mixtures with hydrated lime had more substantial increases in Mr and reduced stress dependencies. Finally, the results were analyzed by plotting master curves using a proposed novel approach called Stress–Temperature Superposition Principle (STSP), which allows for simpler and more straightforward analyses.

Key Performance Analysis of Emulsified Asphalt Cold Recycling Mixtures of the Middle Layer of Pavement Structure.

In the maintenance engineering of asphalt pavement, it is often encountered that both the surface and middle layers are damaged and need to be maintained. The cold in-place recycling technology can be used to simultaneously treat multi-layer diseases and reduce the waste of pavement materials. The cold in-place recycling mixture is rarely used for high layer of pavement structure in high-grade highway. In the supporting practical engineering, the emulsified asphalt cold in-place recycling mixtures were paved as the middle layer of pavement structure by the laying of an overlay. In order to comprehensively evaluate the material performances, coring samples were drilled after cold recycling pavement opening to traffic, and different performance tests were carried out based on the coring samples. The newly paved SMA mixtures were set as the control group. The high temperature stability of cold recycling mixture was analyzed by dynamic creep test and MMLS3 accelerated loading test. Then, the cracking resistance of cold recycling mixture was studied by semi-circular bending test. Finally, the effect of curing time on splitting strength of cold recycling mixture was measured, and the moisture susceptibility was analyzed by dry-wet splitting test and freeze-thaw splitting test. The test results showed that the high temperature stability of cold recycling mixture was worse than SMA mixture. For the cold recycling mixture, the deformation value at the early stage and deformation rate at the stable stage were larger than SMA mixture in the accelerated loading process, and shear failure at high temperature occurred earlier. The cracking resistance of cold recycling mixture was worse than SMA mixture because of the aging effect of the old asphalt and adverse influence of the added cement binder. The effect of curing time on splitting strength of cold recycling mixture was significant, and two stable periods of early strength were, respectively, reached after curing 3 days and 7 days. The indexes of moisture susceptibility, including dry-wet splitting strength ratio and freeze-thaw splitting strength ratio, were obviously lower than that of SMA mixture, and the test values not up to the standard requirement existed. For the emulsified asphalt cold in-place recycling mixture, the improvement of material performances should be focused on, especially the moisture susceptibility. In the research, the emulsified asphalt cold in-place recycling mixtures were acceptably used as the middle layer of maintenance pavement structure. The reliable discussions were summarized based on coring samples collected from real-life road sections. The case can provide guidance and reference for similar engineering applications.

Effects of the addition of fatty acid from soybean oil sludge in recycled asphalt mixtures.

Recycling agents provide better additions of reclaimed asphalt pavement (RAP) in the production of new asphalt mixtures. Alternative and residual materials that have the potential as asphalt binder viscosity reducers have gained visibility in the field of paving due to the perspective of circular economy in recycled mixtures. Soybean oil sludge fatty acid is a material produced from soybean oil sludge, a waste generated in the soybean oil refining step. Thus, this paper investigated the physical, chemical, and rheological effects of the asphalt binder PG 64-XX modified by the fatty acid of soybean oil sludge in the contents of 6% and 7% by weight of the binder. The modified binder samples were submitted to penetration tests, softening point, rotational viscosity, performance grade (PG), before and after short-term aging (RTFO), and multiple stress creep and recovery (MSCR). A control asphalt mixture and recycled asphalt mixtures produced with 40% RAP and fatty acid-modified binders were subjected to tensile strength, induced moisture damage, resilient modulus, and fatigue life. A Student's t statistical test verified the significance of the data, as well as the estimation of production costs of these asphalt mixtures. The use of the fatty acid significantly reduced the stiffness and viscosity of the control asphalt binder, decreasing the mixing temperatures at 14°C and 17°C to 6% and 7%, respectively. Using higher fatty acid contents from soybean oil sludge significantly improved the performance of recycled mixtures in tensile strength, moisture damage, and fatigue life. The production cost of recycled asphalt mixtures was lower than that of the control mixture.

Study on performance deterioration regularity of hot regenerated asphalt mixture under multiple aging factors

Several elements, including ultraviolet light, humidity, temperature, vehicle load, etc., have an impact on the asphalt pavement concurrently during the road service process, gradually diminishing the road’s service level. The self-created Life Cycle Analysis System (LCAS) was employed to simulate the cumulative effects of multiple aging components during the service process. The freeze–thaw splitting test, dynamic creep test, and notched semi-circular bending test were conducted after the hot recycled and the fresh asphalt mixtures were subjected to varying durations of simulated aging. The results indicate that initially, the road performance of the hot recycled asphalt mixture is comparable to the fresh asphalt mixture. However, the fresh asphalt mixture outperforms the hot recycled mixture in all but water stability over time. The attenuation degree of the flow number (FN) differs by 22.5% between the two kinds of mixtures, while the fracture energy differs by 53.3%. The performance of the hot recycled asphalt mixture degrades much more rapidly than that of the fresh asphalt mixture. The LCAS method can well simulate the actual service environment of asphalt pavement constructed with RAP materials and provide help for the performance evaluation of RAP pavement in road engineering and subsequent related research.

Viscoelasticity of Recycled Asphalt Mixtures with High Content Reclaimed SBS Modified Asphalt Pavement

For the concerns of investigating the viscoelastic properties of recycled asphalt mixtures incorporating high content reclaimed styrene-butadiene-styrene (SBS) modified asphalt pavement (RAP-SBS), asphalt mixture performance tester (AMPT) was applied to analyze the dynamic modulus and phase angle of recycled mixtures by the influence of RAP-SBS content, temperature, loading frequency, long-term aging (LOTA), and the incorporation of a rejuvenating agent. Master curves of recycled asphalt mixture regarding dynamic modulus and phase angle are developed, and the viscoelastic properties of recycled mixtures within a wide frequency range are characterized with the Christensen–Anderson–Marastean (CAM) model. Eventually, the one-way analysis of variance (ANOVA) was applied to investigate the role of factors on the viscoelasticity of recycled mixtures. The research indicates that (1) the elastic component of recycled mixtures elevates with the increasing of RAP-SBS content and loading frequency; as a result, the high-temperature stability of it enhances, while it is prone to cracking at low temperatures; (2) RAP-SBS content should be selected according to specific characteristics of pavement. For most cases, a content of 50% is recommended; (3) the recycled mixtures incorporating high-content RAP-SBS mixed with a rejuvenating agent has outstanding aging resistance performance; (4) RAP-SBS content is observed to have a significant influence on the viscoelasticity of recycled mixtures.

Evaluation of water loss and stiffness increase in cold recycled mixes during curing

Implementing cold solutions is one of the primary efforts in the road sector to counteract CO2 emissions and climate change. Using cold recycled mixtures (CRM) permits the reuse of up to 100% of reclaimed asphalt pavement (RAP). This research examines how CRM develop their resilient response during the curing process. Using cyclic loading dynamic triaxial (DTx) testing, resilient moduli of CRM made with various proportions of bitumen emulsion were determined. Curing times from 0 days to 18 months were assessed. Binder content and water loss speed proved to be fundamental factors in the evolution of the resilient moduli of the CRM studied. CRM with a binder content of 2.50% exhibited the best short-term response, while those with a binder content of 3.00% showed greater stiffness values over more extended curing. Once water losses stopped, the CRM continued showing changes in stiffness, proving their evolutionary response.

Multiple Optimization of Cold Reclaimed Asphalt Pavement Mixture

Many asphalt pavements fail structurally after having performed well for some years. In China, when low volume of traffic highway is recycled, the asphalt surface course and the base course stabilized by inorganic stabilizers are sometimes recycled and mixed together to form a new base. Portland cement, lime-fly ash, lime or Portland cement-fly ash is added to improve the strength of the new base, but they are not used at the same time, so it is difficult for a road engineer to select an effective and economical stabilizer. To evaluate the effect and economical efficiency of different stabilizers comprehensively, this paper used Portland cement, lime-fly ash, lime and Portland cement-fly ash to form four kinds of cold recycled mixtures and every kind of cold recycled mixture has 3 mix proportions. The unconfined compression strength, flexural tensile strength, splitting strength, compression resilient modulus, shrinkage performance, water stability performance, fatigue failure and engineering cost of 12 cold recycled mixtures were compared. Finally, the Portland cement-fly ash stabilized mixture with proportion of 5:15:80 was recommended.

Evaluation of mixture grading and binder composition effects on the characteristics of cold-recycled mixtures with foamed bitumen

The investigation was carried out to evaluate the effects of the hydraulic binder's composition on the properties of cold recycled mixtures with foamed bitumen of different gradations. The evaluated hydraulic binders were composed of Portland cement, hydrated lime and cement by-pass dusts. The ratios of these three components simultaneously varied from 20 to 60% in relation to the mass of the resultant hydraulic binder. The mixtures were composed of reclaimed asphalt from a road base (coarse or fine RAP), natural aggregates (0/2 and 0/31.5 mm) in different ratios, hydraulic binder and 70/100 foamed paving grade bitumen. It was shown that the fine and coarse mixtures responded differently to the changes in the composition of the hydraulic binder. It was found that the optimum performance of the fine and coarse graded mixtures required different binder compositions.

Laboratory Performance Evaluation of Asphalt-Treated Cold Recycled Mixtures Using Existing Practical Tests

Agencies currently utilize several proxy tests, related to level of compaction (density) and moisture content, to assess the quality of a recycled pavement during construction. These proxy tests are not completely able to indicate sufficient quality or stability of recycled pavements under trafficking or surfacing, especially at early ages. The lack of sound and rapid tests for use in process control and acceptance during construction limits the use of the recycling techniques by agencies, therefore they do not fully benefit from the advantages that pavement recycling offers. This study evaluates the viability of currently available simple and practical stiffness tests (i.e., soil stiffness gauge and light weight deflectometer tests), deformation resistance tests (i.e., Marshall hammer test), and penetration resistance tests (i.e., dynamic cone penetration test) to characterize the properties of asphalt-treated cold recycled mixtures. The scope of the work included laboratory testing of 18 different cold recycled mixtures, prepared through different processes combining different binding agents and filler types, at different curing times via the selected tests. The collected data were analyzed to evaluate these tests in relation to their repeatability characteristics and versatility to capture the performance of recycled materials with respect to changes in curing time, type of stabilizing/recycling agent, and presence of active filler. The data obtained showed the ability of these tests to capture the effect of curing. Moreover, these tests were found to be sensitive to changes in the recycling agent type, recycling agent content, and presence of active filler.

Simulation and evaluation of fatigue damage of cold recycled mixtures with bitumen emulsion

In order to explore the fatigue damage mechanism of CRME under dynamic load, DEM of CRME was established based on PFC2D. The micromechanical response characteristics of CRME were obtained by simulation splitting test, and verified by indoor indirect tensile fatigue test. It shows that the results of simulation test are basically consistent with those of indoor test. The numerical value and quantity of tensile force chain in DEM increase obviously with the increase of the stress ratio, the fatigue life decays rapidly, and the horizontal displacement at different width positions in the specimen increases significantly. The tensile force chain is generated, accumulated and concentrated in the mortar and the aggregate-mortar interface. Eventually, the micro structure and bonding force of CRME are damaged. Tensile force chain is the main factor of fatigue damage. The improvement of the bonding performance of bitumen emulsion cement mortar (BECM) and RAP-mortar interface is suggested to improve the fatigue performance of CRME.

Evaluating the engineering properties of asphalt mixtures containing RAP aggregates incorporating different wastes as fillers and their effects on the ageing susceptibility

Ageing of asphalt mixtures occurs by intrinsic variables (properties and quantity of the binder and air voids) and extrinsic variables (environmental factors) during production and service life. This topic has been studied extensively in the existing literature, but the potential of alternate filler on the ageing resistance of asphalt mixes and the influence of the interaction between filler and asphalt binder has not been thoroughly examined. The underlying objective of this study was to evaluate the ageing resistance potential of four waste fillers, Jarosite (JS), Hydrated Lime mud (HL), Fly Ash (FA) and Sugarcane Ash (SA), compared to conventional fillers, Stone Dust (SD) on the recycled mix. The recycled mixes were prepared with 50% Reclaimed Asphalt Pavement (RAP) material, locally available natural aggregate, VG-10 grade asphalt binder and studied fillers. The performance properties, including cracking resistance, moisture susceptibility, resilient modulus, rutting, and fatigue resistance of unaged and long-term aged recycled asphalt mix, were evaluated in this study. The results indicated that the ageing resistance of recycled mixtures was highly affected by filler type. HL possesses the highest ageing resistance potential, followed by JS, FA, SA, and SD. The results demonstrated that JS and HL filler significantly improved moisture, rutting, and crack resistance in unaged and long-term aged recycled mix, which are critical factors in extending the durability of pavement. JS and HL filler showed lower fatigue life of recycled mix while tested at higher strain levels due to their higher stiffness. In contrast, FA and SA fillers resulted in a mixed value of properties of the recycled mix compared to SD filler. SA filler showed the lowest cracking resistance (Indirect tensile strength value 1420 kPa for unaged mix and 1573 kPa for aged mix) and moisture resistance (Tensile strength ratio value 78% for unaged mix and 75% for aged mix) among all fillers. The recycled asphalt mix containing SA was found to be highly susceptible to moisture damage, cracking and ageing. The overall conclusions of this study ascertain that the ageing resistance potential of HL was highest among the studied waste fillers for all the studied properties due to its fineness, higher porosity, presence of calcite and increased asphalt film thickness of the mix. • Ageing resistance potential of hydrated lime mud was highest among the studied fillers due to its fineness and the presence of calcite. • Jarosite and hydrated lime mud filler significantly improved moisture, rutting, and crack resistance. • Hydrated lime mud possesses the highest ageing resistance potential among waste fillers, followed by jarosite, fly ash, and sugarcane ash. • Sugarcane ash filler showed the lowest cracking resistance and moisture resistance.

Research on the Performance of Emulsified-Asphalt Recycled Mixture–Based Cement Dosing

In order to solve the problem of semirigid base damage in the initial period of use, this paper focused on emulsified-asphalt cold recycled mixtures with all old mineral and analyzed its strength formation mechanism. The optimum moisture content and amount of emulsified asphalt in the regenerated base were determined through tests, whereas the performance of the mixtures was verified according to the designed optimum ratio. The gray correlation method was used to analyze the performance-influencing factors and determine the rationality of the base designs. The research results can be used for pavement base recycling with a new solution for old roads, and the efficiency of pavement construction was greatly improved. It also reduced the heat and energy loss and contributed to the sustainable environmentally development of road construction.

Numerical and Experimental Analysis of the Raise-Temperature Effect of Quicklime in Cold Recycled Mixtures

This study focuses on the development of a thermodynamic model to individuate the increment of temperature generated by the addition of quicklime as an active filler in cold recycled mixtures (CRMs). CRMs are increasingly popular mixtures primarily composed of reclaimed asphalt pavement (RAP) and produced at low temperatures. CRMs are composed of RAP aggregates, an asphalt stabilizing agent (emulsified or foamed asphalt), fillers and active fillers (traditionally cement or hydrated lime), and water. One of the main limitations of CRMs consists of their workability that requires high air temperature. For this reason, the construction season for the application of cold recycling technologies is usually limited to summertime, especially in colder areas. A solution to this limitation is the use of quicklime as an active filler in the mixture. As shown by previous research, calcium oxide causes an exothermic reaction with water generating heat and increasing the temperature (20°C–25°C) of the entire mixture. This paper presents a thermodynamic model to identify the temperature increase and its evolution during preparation and transportation to the site of CRMs. The scope is to individuate the correct procedure to identify the most suitable application rate of quicklime in the mix design in order to reach the desired CRM temperature and workability.

Study on Low-Temperature and Fatigue Performance of High RAP Content Hot Recycled Asphalt Mixture Based on the Degree of Blending (DOB).

This paper selected three kinds of AC-20 hot-mix recycled asphalt mixtures with high RAP content (30%, 40%, and 50%). It obtains a mixture of different degrees of miscibility by changing RAP preheating temperatures and mixing temperatures. The calculation formula of the degree of blending (DOB) of RAP asphalt interface recycling is proposed. The DSR test quantitatively characterized the DOB mixture's low temperature, and fatigue properties were tested by beam bending test and four-point bending fatigue test. The prediction models of the recycled mixture's low temperature and fatigue properties were proposed. The RAP preheating temperature is the most critical factor that dominates both transfers of RAP asphalt to the surface of new aggregate and the effective blending of old and new asphalt. DOB has a significant great influence on low-temperature performance and fatigue performance. The DOB of recycled asphalt can be improved by adjusting and optimizing the process parameters of plant hot recycled mixture to effectively improve the recycled mixture's low-temperature crack resistance and fatigue lifetime. The optimal RAP dosage and mixing process of required performance can be obtained based on the prediction models to save experimental time and cost.

Preliminary study of linear viscoelasticity limits of cold recycled mixtures determined in Simple Performance Tester (SPT)

The publication presents methodology developed for determination of linear viscoelasticity limits for cold recycled mixtures with cement and bituminous emulsion using Simple Performance Tester (SPT). Methodology was verified on reference materials (PCV and steel dummy specimens, cement concrete and asphalt concrete) to comply with elasticity and viscoelasticity theory. The developed methodology enabled determination of linear viscoelasticity limits for the tested cold recycled mixtures for base course. Tests were conducted for controlled strain ranging from 10 up to 110 µstrain. Linear viscoelasticity limits were determined based on stiffness moduli and phase angles. The combination of binding agents and test temperature had the greatest influence on the obtained values.

Mix design, development, production and policies of recycled hot mix asphalt: A review

Worldwide, flexible pavements are the paramount type of pavements. These national assets can be recycled to serve the next design life without the need to dispose of them in landfill. The old/distressed, flexible pavement material is called, reclaimed asphalt pavement (RAP) material. In view of the sustainable development practice, 100% RAP should be recycled. However, the practical range of RAP incorporation in a drum mix plant ranges from 10% to 50% whereas in a batch mix plant, it is 10%–35%. In a batch mix plant, incorporation of the hot dried RAP (instead of cold RAP feeding) can increase the RAP incorporation level by 20%. Studies recommended that the rejuvenator should be added over the RAP material instead adding with the base binder. The addition of rejuvenator on the RAP conveyor belt (to the pug mill), provided sufficient time for rejuvenating the aged binder coating over RAP aggregates. Further, a thorough knowledge of the mix design process of recycled hot mix asphalt (RAP-HMA) is essential to produce a durable mix. For high RAP content (>20%), the RAP binder properties are important for the mix design process. However, very limited studies discussed (in detail) the recovery process of the RAP binder. The review article through light on the binder recovery process, method of RAP gradation, specific gravity determination for RAP material, minimum desirable properties of the RAP material etc. This review paper also provides a narrative review of the historical development of RAP-HMA technology, technical aspects related to the procurement of RAP material, mix design and production of the recycled mix. Moreover, the international & national policies/laws for construction and demolition waste are discussed. • Parallel heating of RAP in a pug mill increases the mixing ratio. • Performance grade, PG mixing rule was found most reliable. • The mix design process must consider the type of mix plant and RAP feeding method. • Conveyer belt found to be the most promising location for Rejuvenator addition. • The mixing temperature has an equivalent effect as that of a rejuvenator in the recycled mixture. • Stiffness modulus found a promising test to compare the performance of recycled mixtures.

Assessment of the Effect of Nono-clay on Recycled Asphalt Mixtures Resistance to Moisture

Introducing nanotechnology to the pavement industry witnessed a great interest due to the proven benefits of nanotechnology in various scientific fields. However, the reduction in the binder's characteristics might be disadvantageous to the durability of the recycled mixture, making it more susceptible to external factors such as moisture. Therefore, using nanotechnology is expected here to treat this issue. The goal of the current paper is to report on the influence of the nano-clay montmorillonite (MMT) powder (MMT k10) on the resistance to moisture in the hot recycled mixtures or the Reclaimed Asphalt Pavement mixtures (RAP mixtures). In this work, different proportions of rejuvenated RAP were employed. These proportions are 30, 40, and 50% as a percent of the overall weight of the mix. The percentages were mixed with a nano-modified neat binder with (0, 1, 3, and 5)% nono-clay MMT as a proportion of the bitumen’s weight. Two types of mixtures are prepared and used in this paper: nano-modified RAP mixtures and unmodified RAP mixtures. On both types of mixtures, the compressive strength test, the index of retained strength (IRS), the indirect tensile strength tests (ITS), and the tensile strength ratio (TSR) were carried out to compare and evaluate the moisture resistance of rejuvenated RAP mixtures. The experimental test results indicated that using 5 percent nono-clay in regenerated RAP mixes provides better performance than not using it. where it increased moisture damage resistance by5.53% for IRS value and 3.66% for TSR for 50 percent RAP mixes.

Permanent Deformation Assessment of Cold Recycled Asphalt Mixtures

The objective of this study was to evaluate the behavior in terms of the permanent deformation of four cold recycled asphalt mixtures stabilized with asphalt emulsion and foamed asphalt. The analysis was conducted considering three flow number test procedures adapted for cold recycled mixtures: (i) ABNT NBR 16505 (method A); (ii) adaptation of the FN test for CRAM according to Kim and Lee’s method (method B); (iii) 3D-Move analysis software simulation of pavement structures to address the stress magnitude for the FN test (method C). The influence of the curing process on the performance of the materials was also verified. The study used an extensive database of computed pavement responses from the four different asphalt pavement structures of the experimental section subjected to axial loading of a tandem axle using the 3D-Move pavement response analysis program. The FN results using the 3D-Move data (method C) demonstrated the good mechanical behaviour with respect to permanent deformation of the cold recycled mixtures subject to axial stress and temperature. The method proposed by Kim and Lee (method B) showed little efficacy for the analysis of the CRAMs tested in this work. The ABNT NBR 16505 method (method A), conventionally used for HMA, highlighted the influence of temperature (60°C) on the CRAM mixtures. For all FN test conditions, the curing was a preponderant factor for the performance of cold recycled asphalt mixtures and should be carefully evaluated to simulate the early stage of the mixtures in the field. It is also important to verify the influence of humidity and temperature on the permanent deformation mechanism of cold recycled asphalt mixtures.