Aged Binder Research Articles

Evaluation of Cracking Resistance of SMA-13 Hot Recycling Asphalt Mixtures Reinforced by Basalt Fiber.

In the context of green and low-carbon development, energy saving, and emission reduction, hot recycling technology (RT) has been researched, which is divided into hot central plant RT and hot in-place RT. However, due to the aged asphalt binders, the shortcomings of hot recycled asphalt mixtures have become apparent, as in comparison to new asphalt mixtures, their resistance to cracking was inferior and the cracking resistance deteriorated more rapidly. Therefore, it was very necessary to focus on the improvement of crack resistance of hot recycled asphalt mixtures. Basalt fiber has been proved to be able to effectively improve the comprehensive road performance of new asphalt mixtures. Therefore, this paper introduced basalt fiber to hot central plant recycled and hot in-place recycled asphalt mixtures, in order to improve the crack resistance of asphalt as a new type of fiber stabilizer. Firstly, six types of SMA-13 fiber asphalt mixtures were designed and prepared, i.e., hot mixtures with basalt fiber or lignin fiber, hot central plant recycled mixtures with basalt fiber or lignin fiber, and hot in-place recycled mixtures with basalt fiber or lignin fiber. Secondly, the trabecular bending test, low-temperature creep test, semi-circular bending test, and IDEAL-CT were used to comparatively study the changing patterns of low and intermediate temperature cracking resistance of hot recycled mixtures with conventional lignin fibers or basalt fibers. Finally, Pearson's correlation coefficient was used to analyze the correlation of the different cracking resistance indicators. The results show that the low and intermediate temperature cracking resistance of hot central plant recycled mixtures increased by 45.6% (dissipative energy ratio, Wd/Ws) and 74.8% (flexibility index, FI), respectively. And the corresponding cracking resistance of hot in-place recycled mixture increased by 105.4% (Wd/Ws) and 55.7% (FI). The trabecular bending test was more suitable for testing the low-temperature cracking resistance of hot recycled asphalt mixtures, while the IDEAL-CT was more suitable for testing the intermediate-temperature cracking resistance. The results can provide useful references for the utilization of basalt fiber in the hot recycling of SMA-13 asphalt mixtures.

Asphalt pyro-rejuvenators based on waste tyres: An approach to improve the rheological and self-healing properties of aged binders

Waste Tyres (WT) are a significant fraction of industrial waste and a source of environmental hazards with limited valorisation. To reduce this problem, currently there is a growing interest in valuing the WT through pyrolysis to obtain multifunctional liquids to improve the rheological and self-healing properties of aged binders. This research provides a comprehensive study on using WT mixtures as precursors for asphalt rejuvenators by means of pyrolysis and distillation processes. To this end, WT polymeric fractions from light (WT-L) and mining trucks (WT-M) were used as feedstock and characterised for compositional and thermal properties. Additionally, micropyrolysis coupled with gas chromatography/mass spectrometry (Py-GC-MS) was used to identify the major products in pyrolysis vapours, to elucidate the reaction maps describing thermal degradation of WTs and to predict the feasible reaction conditions. The pyrolysis liquids were produced after a screening of reaction conditions and subjected to distillation, following a response surface model to produce an optimised pyro-rejuvenator. The results showed that the pyrolytic rejuvenator obtained through pyrolysis at 465 °C and distillation cutting at 160–200 °C is mainly composed of hydrocarbons and aromatic substances (95.5%), with a significant proportion of limonene (33.71%). Furthermore, the pyrolytic rejuvenator exhibited highly desirable physical properties in the context of its application and excellent oxidative stability (85.7%). Otherwise, it was determined that bitumen mixtures with 3%–6% doses of pyro-rejuvenator improved the viscosity, softening point, and penetration of aged binders, restoring their physical properties to the virgin state. In conclusion, pyro-rejuvenators can be successfully used as a promising solution to produce more durable and sustainable pavements with improved rheological and healing properties.

Influences of soy agent rejuvenator on the performance of Reclaimed Asphalt Pavement (RAP) properties

The paving industry has had extraordinary accomplishments with reusing Reclaimed Asphalt Pavement (RAP) in road construction in recent decades. This study presents the influences of using a soy-agent rejuvenator on the extracted aged binder from RAP material. The test method practices include major binder properties such as viscosity, stiffness, and physicochemicals. Different percentages of the soy agent have been used as additives to the reclaimed binder. Based on the analysis results, 10% of soy agent to binder by weight will be the optimal percentage of soy agent for improving the mechanical properties of the rejuvenated asphalt binder for RAP.

Performance characterization of long-term aged bitumen: Field and laboratory investigation

Aging of binder affects the service life of flexible pavements. Aging involves change in physical, rheological, chemical and morphological characteristics of binder making it hard and brittle resulting in pavement deterioration. Oxidation and volatalization are the two main mechanisms involved in aging. Aging stiffens the binder as it increases the viscosity of binder resulting in pavement distresses like fatigue cracking, ravelling and thermal cracking. Hence, it is obligatory to examine the aging effects on binder to predict the service life of flexible pavements. In this study, core samples are collected from 15 years aged in-service pavement section and fresh binder was aged for varying aging duration in the laboratory to simulate field aging condition. Field aged and laboratory aged binders were subjected to physical, chemical, rheological and morphological investigations for evaluating the variation of these properties with long-term aging. It is evident that the traffic speed influences the dynamic viscosity of binders. With aging, the rutting resistance of binders improved and fatigue resistance of binders diminished considerably. The severity of aging in binder increases with pavement depth in the field and 8 days of normal oven aging in the laboratory simulates 15 years field aging condition.

Thermal Oxidative Aging Effect on Chemo-Rheological and Morphological Evolution of Crumb Rubber Modified Asphalt Binders with Wax-Based Warm Mix Additives

Wax-based warm mix additives can decrease the viscosity and improve the workability of crumb rubber (CR)-modified asphalt, but the mechanism of influence on the aging performance of CR-modified asphalt is not clear. To investigate the thermal aging behavior and mechanism of wax-based warm mix CR-modified asphalt, polyethylene wax (PEW) and polyamide wax (PAW) were mixed to prepare warm mix CR-modified asphalt. The effect of thermal aging on the rheological and mechanical properties was characterized by a basic property test, frequency sweep test, and multiple stress creep recovery test. The chemical composition changes during aging were then analyzed by Fourier transform infrared spectroscopy and gel permeation chromatography. Finally, the phase morphology during thermal aging was observed by fluorescence microscopy. The results showed that compared with the degradation of CR, the oxidative aging of the asphalt binder played a dominant role in the process. Not only did PEW and PAW attach to the asphalt surface in the form of crystallization to prevent its reaction with oxygen but they also promoted the dissolution of CR, and released polymerization chains, thereby enhancing the antiaging properties of CR-modified asphalt. Furthermore, the antiaging of PAW/CR-modified asphalt was better than that of PEW/CR-modified asphalt, because the amide group of PAW reacted with CR-modified asphalt to form a polymer structure.

Investigation into the effect of waste engine oil and vegetable oil recycling agents on the performance of laboratory-aged bitumen

The pavement recycling method is one of the practical ways to integrate sustainable development into transportation infrastructure, and it has been adopted worldwide. The use of reclaimed asphalt pavement (RAP) in new asphalt highways is limited due to the ageing effects caused by UV damage and weathering on the asphalt binder. To address this issue, waste vegetable oil (WVO) and waste engine oil (WEO) have been proposed as potential rejuvenating agents to enhance the recyclability of pavements containing RAP. This study evaluated the effectiveness of WEO and WVO as chemical rejuvenating agents through various tests on both aged and virgin asphalt binders. The tests included measurements of ductility, fire, and flash points, softening points, and penetration. The results indicate that the addition of WEO and WVO can improve the low-temperature properties of asphalt binders when mixed with RAP, resulting in reduced stiffness. The mixture containing WEO and WVO exhibited improved stability compared to the control, suggesting enhanced flow with increasing waste oil content in comparison to aged binder, albeit with slightly reduced flow compared to the virgin binder. This study demonstrates the potential of WEO and WVO as recycling agents to enhance the performance of bituminous mixes incorporating RAP.

Evaluation of the laboratory aging of field-blended crumb rubber modified binder

Field-blending approach is widely employed by the industry to introduce crumb rubber into asphalt binder. Rubber-modified binder provides satisfactory performance and benefits the environment by consuming recycled rubber manufactured from scrap tires. This work investigated the aging mechanism and post-aging performance of rubber-modified binders using laboratory aging protocols. Four rubber-modified binders containing two rubber contents (5 and 10 percent) and two particle sizes (passing 1.18 mm and 2.36 mm, respectively) were evaluated in this study. After multiple laboratory aging protocols, chemical components in aged binders were measured with Fourier transform infrared spectroscopy. Chemical analysis revealed that rubber-modified binders accumulated fewer oxidative aging products (carbonyl and sulfoxide components) than their unmodified base binder after long-term aging. Increasing rubber content and particle size increased the complex shear modulus while decreasing the phase angle of the binder. Binder viscosities were back-calculated from complex moduli and phase angles. A linear correlation between logarithmic viscosity and carbonyl area index exists for the long-term aged rubber-modified binders. This linearity can be used to predict the age-hardening of rubber-modified binders. These binders were also tested in dynamic shear rheometer to determine performance grades. Multiple stress creep recovery tests evaluated the rutting resistance of short-term aged binders. Bending beam rheometer was used to evaluate the low-temperature cracking resistance of long-term aged binders. These test results showed that rubber-modified binders provided better rutting and cracking resistance than their base binder. Statistical analysis indicated that carbonyl components correlated to the binder performance at various aging statuses.

In-situ detection on near-infrared spectra fingerprints of asphalt mixture after laboratory short- and long-term aging

Although Fourier transform infrared spectroscopy has been widely used in research on the aging of asphalt binders, it is a cumbersome, time-consuming, and environmentally polluting process using toxic solvents to extract and recover asphalt binders from asphalt mixtures for spectral measurement and analysis. However, little effort has been devoted towards its non-destructive spectral measurement, which is important for intelligent monitoring of pavement deterioration conditions. This paper focused on the non-destructive investigation of comparative near-infrared spectra of asphalt mixture specimens designed using the Marshall method after laboratory short- and long-term aging with a portable near-infrared spectrometer. The near-infrared spectra showed that asphalt mixtures from different aging states appeared significantly different fingerprints. The near-infrared fingerprints and aging states were also statistically significantly different according to the analysis of one-way analysis of variance. These distinctive near-infrared fingerprints could be attributed to the varied amounts of chemical functional groups, mainly hydrogen-containing groups during oxidative aging. This study provided a non-destructive and in-situ detection of the aging of asphalt mixtures.

Influence of Petroleum-Based and Bio-Derived Recycling Agents on High-RAP Asphalt Mixtures Performance

Reclaimed asphalt pavement (RAP) has been utilized as a potential partial substitute for virgin asphalt binder in asphalt mixtures. However, a primary concern with increasing RAP content in asphalt mixtures is the cracking potential, attributed to the aged RAP asphalt binder (RAP-binder). To address this, the use of petroleum-based and bio-derived recycling agents (RAs) in enhancing the cracking resistance of high-RAP asphalt mixtures has been explored. The objective of this study is to ascertain the effectiveness of six RAs in mitigating cracking in high-RAP asphalt mixtures. The RAs considered include petroleum-crude-oil-derived aromatic oil, soy oil, and four types of tall-oil-derived phytosterol (industrial by-product, intermediate, purified, and fatty acid-based). The RAs’ dosages were optimized, based on RAP-binder and unmodified asphalt binder properties, to produce target PG 70-22 asphalt binder when incorporated in asphalt mixtures containing 30% RAP. To assess the engineering performance of these 30%-RAP asphalt mixtures for each RA, a conventional asphalt mixture incorporating styrene-butadiene-styrene (SBS)-modified PG 70-22 asphalt binder without RAP or RAs was benchmarked for comparison. Mechanical tests performed included Hamburg wheel-track testing (HWTT), intermediate-temperature fracture tests (semi-circular bend, Illinois flexibility index, and IDEAL cracking tolerance), and thermal stress-restrained specimen tensile strength test to evaluate permanent deformation, intermediate-temperature cracking resistance, and low-temperature cracking resistance, respectively. Results showed that petroleum-crude-oil-derived aromatic oil and tall-oil-derived fatty-acid-based oil RAs were able to rejuvenate RAP-binder as measured by the cracking tests performed. Further, the use of these RAs did not adversely impact the asphalt mixtures’ permanent deformation performance.

Effect of SBS/SBR/component molecular compatibility on anti-aging properties for asphalt binder

To explain the effect of SBS/SBR/component molecular compatibility on anti-aging properties for asphalt binder, the micro-aging behavior of SBS/SBR composite modified asphalt binder was studied by molecular simulation, scanning electron microscopy (SEM) and infrared spectroscopy (IR). First, the micro-models of SBS molecule, SBR molecule and component molecule (asphaltene, resin, saturation, aromatic) were established, and the molecule number was determined by component test. Additionally, the characteristics of micro-model were analyzed, and the change characteristics of molecular compatibility for unaged asphalt binder and aged asphalt binder were obtained. Lastly, the rationality of molecular compatibility simulation results of SBS/SBR/component was demonstrated by SEM and IR tests, respectively. The results show that there is a close relationship between SBS/SBR/component molecular compatibility and asphalt binder anti-aging performance. The change of molecular space structure leads to the increase of asphalt binders density and the decrease of intermolecular distance. The study revealed the anti-aging properties of asphalt binder from the aspect of SBS/SBR/component molecular compatibility, which provided a theoretical foundation for the improvement of its aging resistance.

Evaluation of asphalt mixes performance characteristic with mustard oil as a rejuvenator

This study investigated the effects of adding natural renewable mustard oil (Mo) as a rejuvenator, and reclaimed asphalt pavement (RAP) to asphalt mixes for pavement maintenance and rehabilitation. Mo was utilized 10% by weight of binder with 30% RAP in modified asphalt mixes using two types of aggregate gradations. Performance characteristics of neat and modified asphalt mixes are evaluated through fatigue resistance, rutting resistance, and moisture damage resistance testing. The experimental results revealed that the addition of 10% Mo effectively rejuvenates asphalt mixes containing RAP by softening the aged binder typically from 6% to 14%. The bending fatigue resistance of modified asphalt mixes improves from 14% to 26%, rutting resistance decreases from 12% to 14% whereas moisture damage resistance also decreases from 12% to 16% respectively as compared to neat mixes. This research presents sustainable and cost-effective solution for utilizing Mo and RAP used in asphalt mixes for pavement maintenance and rehabilitation.

A molecular dynamics simulation study on the recovery performance of aged asphalt binder by waste vegetable oil rejuvenators

This study employed molecular dynamics to simulate the recovery performance of a waste vegetable oil rejuvenator on aged asphalt binder. The model's accuracy was verified through density and glass transition temperature (Tg) calculations. The Radial Distribution Function (RDF) was utilized to assess the aggregation state of different asphalt binder components. The impact of the waste vegetable oil rejuvenator on asphalt binder microstructure was evaluated using cohesive energy density (CED), relative concentration, mean square displacement (MSD), radius of gyration (Rg), and free volume amount. Changes in functional groups of the aged and recycled asphalt binder samples were analyzed using Fourier transform infrared spectroscopy (FT-IR). Results indicate that the rejuvenator significantly influences the dispersion of SARA components. Improved compatibility between aged and virgin asphalt binders is achieved through increased activity of asphaltenes and resins. The incorporation of rejuvenators into asphalt binder mildly counters the aggregation of asphalt binder molecular structure, mitigates the negative effects of aging, and restores asphalt binder structure. The rejuvenator, enriched with polar groups as per FT-IR tests, increases the proportion of polar groups in the recycled asphalt binder. The recycled asphalt binder exhibits a higher proportion of polar molecules, and the rejuvenator reacts with the polar molecules in the asphalt binder at high temperatures.

Effects of Thermo-Reversible Aging on the Cracking Resistance of Asphalt Mixtures in the Semi-Circular Bend Test

The semi-circular bend (SCB) test has been widely used to evaluate the cracking resistance of asphalt mixtures. However, uncertainty has arisen with respect to the accuracy of the test method in cold regions where thermo-reversible aging of the asphalt binder plays a significant role in determining the cracking resistance of asphalt pavement. This study aimed to optimize the current SCB protocol by including an evaluation of thermo-reversible aging phenomena. Asphalt mixtures were collected from different regions in North America. Two groups of SCB samples were prepared, with one tested at 0°C after 2 h of conditioning at the test temperature, and the other tested at the same temperature after 72 h of conditioning at −20°C. The SCB tests were conducted at 50 mm/min and the force was recorded versus both the vertical load line displacement and horizontal crack mouth opening displacement (CMOD). To quantify the effects of thermo-reversible aging on cracking resistance, indicators including the flexibility index (FI), fracture energy (FE), cracking resistance index (CRI), balanced cracking index (BCI), and cracking initiation index (CII) were calculated. The results show that the FI and BCI are greatly affected by cold conditioning, decreasing by 34.6 % and 22.3 %, respectively. The post-peak slope of the force–CMOD curve deteriorates to varying degrees, which provides guidance for optimizing the current SCB protocol to better rank the low-temperature cracking resistance of asphalt mixtures. In contrast, the CII is affected to only a minor degree by thermo-reversible aging and is also a preferred indicator from a repeatability perspective. Important variations in stress relaxation ability (e.g., m-value, phase angle), and how these respond to cold conditioning, are missed in rapid SCB mixture tests and therefore best determined on recovered asphalt binder.

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

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

Investigation of cracking resistance of cold asphalt mixture designed for ultra-thin asphalt layer

Ultra-thin asphalt layers are mostly constructed at high producing temperatures of 165–180 ℃, which results in high energy consumption and extra aging of asphalt binders. Those influences could be eliminated by employing the cold-mix process. However, the reduced cracking resistance of cold asphalt mixtures should be addressed. The objective of this study is to design a preferable cold mix asphalt mixture which can be used for ultra-thin asphalt layer. A cold mix ultra-thin asphalt layer (GT-10 C) with comparable anti-cracking performance was developed through the use of high-performance binder, basalt fibers, and specially designed aggregate gradation. Several cracking resistance tests were employed including the low-temperature bending test, impact toughness test, and semi-circular bending test. In addition, a specified test method was developed for determining cracking resistance and durability of the ultra-thin asphalt layers by using compounded slabs. The testing results were compared with the performance of a conventional hot mix ultra-thin asphalt layer (Hot-UA) and a common micro-surfacing layer with cold mix (Cold-UA). It was found that GT-10 C had larger ultimate tensile strain, impact and fracture toughness than Hot-UA and Cold-UA, and a better fracture life in the thin layer cracking resistance test as well. This research provides a potential technology for producing cold mix ultra-thin asphalt layers.

Rejuvenating oxidized paving asphalts – When softeners meet asphaltene dispersants

The search and development of various asphalt rejuvenators have been following a trial-and-error methodology in essence; the imperative need of improved efficiency and versatility yearns for a general principle/framework of formulating rejuvenators. In this study, we propose one such formulation concept that rejuvenators can be designed by combining asphaltene dispersants (interacting with and dispersing asphaltenes) with softeners (diluting asphaltenes). This concept was preliminarily validated in an experimental program involving three rejuvenation schemes, namely using an aromatic softener alone (as the reference) and using it together with an ionic liquid or a phenolic compound (both acting as dispersants). Immediate and long-term rejuvenating effectiveness was evaluated based on viscoelastic properties, fatigue resistance, and moisture susceptibility. The results indicated that at respective optimum dosages, the three schemes all yielded satisfactory immediate performance of rejuvenation. After long-term aging, the rejuvenated asphalts demonstrated more desired viscoelastic characteristics in resisting high-temperature deformation and low-temperature cracking, and were more fatigue resistant, as compared to the virgin binder. Rejuvenation in all cases also recovered the moisture resistance nearly to the virgin level. Infrared spectrum analysis indicated that the performance restoration was accomplished by the agents blending physically with the aged binder, which decreased the concentrations of oxidation functional groups (carbonyl and sulfoxide). The incorporation of dispersants improved the aging resistance (in terms of high temperature viscoelasticity), and substantially reduced the need of aromatic softener while providing similar or better performance compared to using the softener alone, which would lead to pronounced environmental and economic benefits. The much higher dosage efficiency was ascribed to the capability of the dispersants in peptizing and dissociating the asphaltenes, as investigated by molecular dynamics simulations. The different dispersing behaviors of the additives were examined with reference to their chemical compositions and molecular structures.

State of the Art Review of Ageing of Bituminous Binders and Asphalt Mixtures: Ageing Simulation Techniques, Ageing Inhibitors and the Relationship between Simulated Ageing and Field Ageing

Asphalt mixtures age during service in the field, primarily as the result of chemical changes in the bituminous binder phase. The ageing phenomenon changes the properties of the asphalt mixture, including the stiffness modulus, the resistance to deformation and the resistance to cracking, and it leads to surface weathering or erosion that often leads to pavement resurfacing. Consequently, many researchers have attempted to understand and to simulate the ageing of bituminous binders and asphalt mixtures in the laboratory. This review of bituminous binder and asphalt mixture ageing considers ageing simulation techniques, the effect of ageing on both bituminous binders and asphalt mixtures, the potential benefits of ageing inhibitors, and efforts to relate simulated laboratory ageing to observed field ageing. It is concluded that ageing has a significant effect on the properties of bituminous binders and asphalt mixtures, and that improved simulated ageing is important for comparing the effect of ageing on different materials and mixtures, as well as for quantifying the potential benefits of ageing inhibitors, which have generally been promising. It is also concluded that current ageing protocols are based on heat only, omitting the important contribution of solar radiation to the weathering and ageing of asphalt surfaces in the field. In the future, different simulated ageing protocols should be developed for binder and mixture samples. Similarly, a different ageing protocol is appropriate for understanding base-layer fatigue, compared to research on surface-layer weathering. Finally, it is concluded that a universal ageing protocol is unlikely to be found and that mixture- and climate-specific protocols need to be developed. However, given the importance of simulated ageing to asphalt researchers, the development of reliable, robust and calibrated laboratory ageing protocols is essential for the future.

Correlation between Deformation and Volumetric Characteristics in the Aging Condition of Hot Mix Asphalt

The surface layer of pavement structures tends to experience a decrease in performance as its service life approaches. Generally, this decrease in performance is caused by aggregate degradation and aging of the asphalt binder, which can be caused by traffic loads or weather exposure. The mechanical performance of asphalt mixtures is due to the effects of aggregate degradation, which was simulated by reducing the coarse aggregate fraction and adding medium and fine aggregate fractions. The asphalt aging process simulates changes in binder characteristics by adding RAP binder to Pen 60/70 asphalt. Hot mix asphalt (HMA) with new material (SA-1) as a control for degradation simulation (SA-2, SA-3 and SA-4). Marshall test results show that aggregate degradation significantly causes a decrease in voids in the mixture (VIM) and voids in mineral aggregate (VMA), as well as an increase in voids filled with asphalt (VFA). WTM test results show that HMA degradation causes an increase in rutting depth, which increases the deformation rate and decreases dynamic stability. The correlation results between WTM and Marshall tests show a negative exponential relationship between VIM and VMA with deformation and a positive exponential relationship between VFA and asphalt mixture deformation.

Ecuadorian asphalt aging in laboratory and field. Relationships and analysis

The aging of asphalt binders has a great impact on the behavior of pavement. The specifications for performance grade include tests on short-term (RTFOT) and long-term (PAV) aged residues. However, aging is greater at the top of wearing course than deeper zones, long-term tests do not correlate accurately with field aging and in the latter, the incidence of local temperature is not considered accurately. The objective is to relate the aging of Ecuadorian asphalt at the laboratory level, applying different conditioning times in the PAV, with the field aging from asphalts recovered from the top of pavements surface in selected roads of the Andean and Coastal regions, with different construction times and cumulated degree-days (CDD), using certain rheological parameters. As a result, in the Ecuadorian asphalt, the RTFOT residue is equivalent to field aging of 1.1 years in the Coastal region and 1.7 years in the Andean region. On the other hand, the usual PAV of 20 hours corresponds to field aging of 5.8 years for the Coastal region and 9.3 years for the Andean region. The progressive evolution of damage to our roads, without considering traffic, corresponds to conditioning times in the PAV between 13.0 and 26.6 hours.

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

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