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

2022 ◽  
Vol 13 (1) ◽  
pp. 140-152
Author(s):  
Eslam Deef-Allah ◽  
Magdy Abdelrahman

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.

2020 ◽  
Vol 2020 ◽  
pp. 1-24
Author(s):  
Weiying Wang ◽  
Songchang Huang ◽  
Yongchun Qin ◽  
Yiren Sun ◽  
Rui Dong ◽  
...  

With the development of pavement recycling technology, the requirement of reclaimed asphalt pavement (RAP) is substantially increasing. Warm-mix recycled asphalt (WMRA) technology has made great progress, which can effectively decrease the working temperature and improve the RAP content. In this study, the rheological properties of recycled binders with incorporation of high-percentage artificial RAP binder (30–70%) were evaluated using two types of warm-mix asphalt (WMA) additives, i.e., polyethylene wax R and surfactant M. The dynamic shear rheometer (DSR) and beam bending rheometer (BBR) tests were conducted on the recycled binders. The results showed that the temperature and frequency played an important role in determining the complex shear modulus of the high-percentage WMRA binders. The dependency of phase angle on frequency increased after the long-term aging. The WMA additive R had a relatively huge impact on the rheological properties of asphalt, which mainly occurred before the PAV aging of recycled asphalt binder; the WMA additive M had no significant impact on the rheological properties of recycled asphalt binder. The WMA additive R enhanced the low-temperature rheology of recycled asphalt binder, while the WMA additive M enhanced the high-temperature rheology of recycled asphalt binder. Both of these types of WMA additives improved the antifatigue performance of recycled asphalt binder. The increased content of RAP binder improved the high-temperature performance and reduced the low-temperature performance of the recycled asphalt binder. However, it had no obvious impact on the fatigue performance. In addition, there was a good linear relation between the RAP binder content and the two indexes of the multiple stress creep recovery (MSCR) test.


2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Mojtaba Mohammadafzali ◽  
Hesham Ali ◽  
James A. Musselman ◽  
Gregory A. Sholar ◽  
Aidin Massahi

Fatigue cracking is an important concern when a high percentage of Reclaimed Asphalt Pavement (RAP) is used in an asphalt mixture. The aging of the asphalt binder reduces its ductility and makes the pavement more susceptible to cracking. Rejuvenators are often added to high-RAP mixtures to enhance their performance. The aging of a rejuvenated binder is different from virgin asphalt. Therefore, the effect of aging on a recycled asphalt mixture can be different from its effect on a new one. This study evaluated the cracking resistance of 100% recycled asphalt binders and mixtures and investigated the effect of aging on this performance parameter. The cracking resistance of the binder samples was tested by a Bending Beam Rheometer. An accelerated pavement weathering system was used to age the asphalt mixtures and their cracking resistance was evaluated by the Texas Overlay Test. The results from binder and mixture tests mutually indicated that rejuvenated asphalt has a significantly better cracking resistance than virgin asphalt. Rejuvenated mixtures generally aged more rapidly, and the rate of aging was different for different rejuvenators.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3986
Author(s):  
Huan-Yun Zhou ◽  
Huai-Bing Dou ◽  
Xian-Hua Chen

Aiming to improve the comprehensive road performance of asphalt binders, especially the high-temperature performance, a novel asphalt binder was prepared by compounding high-quality and low-cost polyethylene (PE) with graphene (GNPs) using a high-speed shearing machine. The rheological properties and interaction mechanism of PE/GNPs composite modified asphalt were investigated using temperature sweep (TeS), multiple stress creep recovery (MSCR), linear amplitude sweep (LAS) and Fourier transform infrared spectroscopy (FT-IR) and field emission scanning electron microscopy (FESEM). The experimental results demonstrated that GNPs and PE can synergistically improve the high-temperature performance of asphalt binders and enhance the rutting resistance of pavements; the pre-blended PE/GNPs masterbatch has good medium-temperature fatigue and low-temperature cracking resistance. Meanwhile, PE/GNPs dispersed uniformly in the asphalt matrix, and the microstructure and dispersion of premixed PE/GNPs masterbatch facilitated the asphalt modification. No new absorption peaks appeared in the FT-IR spectra of the composite modified asphalt, indicating that asphalt binders were physically modified with GNPs and PE. These findings may cast light on the feasibility of polyethylene/graphene composite for asphalt modification.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xuancang Wang ◽  
Yuchen Guo ◽  
Guanyu Ji ◽  
Yi Zhang ◽  
Jing Zhao ◽  
...  

The growth of aquaculture has increased the production of oysters. However, the increased oyster shell volume has created serious environmental and recycling problems for the society. In order to study the sustainable utilization of waste oyster shells, asphalt binder of waste oyster shell powder was prepared by using modified asphalt material with waste oyster shells. The microstructure of oyster shell powder was analyzed by scanning electron microscopy experiments. The chemical composition of the asphalt binder was observed by Fourier transform infrared spectroscopy tests. The physical properties of the asphalt binder, including softness, high-temperature performance, and plastic deformation capacity, were initially evaluated through three indicators’ tests on asphalt. A preliminary performance evaluation of the asphalt binder was performed. The high-temperature stability of asphalt binders was evaluated using dynamic shear rheometry. The rutting resistance of the material was evaluated by temperature sweep tests, and the shear deformation resistance of the material was evaluated by frequency sweep tests. Multiple stress creep recovery tests determine the material’s ability to resist permanent deformation. The low-temperature rheological properties were evaluated by bending beam rheology tests. The study found that the waste oyster shell powder is a biomass with a porous irregular petal shape. No new characteristic absorption peaks are formed by mixing with asphalt. And, it can improve the viscosity, thermal stability, and temperature-sensitive properties of the material. It significantly improved the high-temperature rheological performance, rutting coefficient, and recovery elasticity of the material. However, it has little effect on low-temperature rheological performance. This study provides a solid foundation for the effective use of biowaste in engineering materials.


2022 ◽  
Vol 13 (1) ◽  
pp. 231-249
Author(s):  
Eslam Deef-Allah ◽  
Magdy Abdelrahman

Reclaimed asphalt pavement (RAP) has been used in asphalt mixes for several years in the United States. However, the interactions between the RAP binder and the virgin asphalt binder (VAB) need further investigations. Thus, the main objective of this study was to explore the rheological and chemical properties of extracted asphalt binders (EABs) from plant, field, and lab mixes. The plant mixes were collected from behind the paver, reheated to the compaction temperature, and compacted in the lab. The field mixes were collected as cores within two weeks after the end of the construction process. The lab mixes were fabricated in the lab using the same materials used in the plant and field mixes. The mixes contained high asphalt binder replacement percentages by RAP, which were greater than 30%. The EABs were treated as rolling thin film oven aged VABs (RTFO AVABs). The rheological properties of EABs and RTFO AVABs were analyzed using temperature sweep, frequency sweep, and multiple stress creep recovery tests. Chemical investigations of EABs and RTFO AVABs were carried out using Fourier transform infrared spectroscopy and thermogravimetric analysis. The EABs from plant or lab mixes showed higher stiffnesses than EABs from field mixes. This occurred because of the extra heating that was implemented for the plant mixes before the compaction in the lab, which caused more interactions between the RAP binder and VABs. The fabrication mechanism, mixing and short-term aging processes, used in lab mixes caused more interactions between RAP binder and VABs than in the field mixes.


Author(s):  
Moses Akentuna ◽  
Louay N. Mohammad ◽  
Sanchit Sachdeva ◽  
Samuel B. Cooper ◽  
Samuel B. Cooper

Moisture damage of asphalt mixtures is a major distress affecting the durability of asphalt pavements. The loaded wheel tracking (LWT) test is gaining popularity in determining moisture damage because of its ability to relate laboratory performance to field performance. However, the accuracy of LWT’s “pass/fail” criteria for screening mixtures is limited. The objective of this study was to evaluate the capability of the LWT test to identify moisture susceptibility of asphalt mixtures with different moisture conditioning protocols. Seven 12.5 mm asphalt mixtures with two asphalt binder types (unmodified PG 67-22 and modified PG 70-22), and three aggregate types (limestone, crushed gravel, and a semi-crushed gravel) were utilized. Asphalt binder and mixture samples were subjected to five conditioning levels, namely, a control; single freeze–thaw-; triple freeze–thaw-; MiST 3500 cycles; and MiST 7000 cycles. Frequency sweep at multiple temperatures and frequencies, and multiple stress creep recovery tests were performed to evaluate asphalt binders. LWT test was used to evaluate the asphalt mixture samples. Freeze–thaw and MiST conditioning resulted in an increase in stiffness in the asphalt binders as compared with the control. Further, freeze–thaw and MiST conditioning resulted in an increase in rut depth compared with the control asphalt mixture. The conditioning protocols evaluated were effective in exposing moisture-sensitive mixtures, which initially showed compliance with Louisiana asphalt mixture design specifications.


2021 ◽  
Vol 13 (18) ◽  
pp. 10271
Author(s):  
Yuchen Guo ◽  
Xuancang Wang ◽  
Guanyu Ji ◽  
Yi Zhang ◽  
Hao Su ◽  
...  

The deteriorating ecological environment and the concept of sustainable development have highlighted the importance of waste reuse. This article investigates the performance changes resulting from the incorporation of shellac into asphalt binders. Seashell powder-modified asphalt was prepared with 5%, 10%, and 15% admixture using the high-speed shear method. The microstructure of the seashell powder was observed by scanning electron microscope test (SEM); the physical-phase analysis of the seashell powder was carried out using an X-ray diffraction (XRD) test; the surface characteristics and pore structure of shellac were analyzed by the specific surface area Brunauer-Emmett-Teller (BET) test; and Fourier infrared spectroscopy (FTIR) qualitatively analyzed the composition and changes of functional groups of seashell powder-modified asphalt. The conventional performance index of seashell powder asphalt was analyzed by penetration, softening point, and ductility (5 °C) tests; the effect of seashell powder on asphalt binder was studied using a dynamic shear rheometer (DSR) and bending beam rheometer (BBR) at high and low temperatures, respectively. The results indicate the following: seashell powder is a coarse, porous, and angular CaCO3 bio-material; seashell powder and the asphalt binder represent a stable physical mixture of modified properties; seashell powder improves the consistency, hardness, and high-temperature performance of the asphalt binder but weakens the low-temperature performance of it; seashell powder enhances the elasticity, recovery performance, and permanent deformation resistance of asphalt binders and improves high-temperature rheological properties; finally, seashell powder has a minimal effect on the crack resistance of asphalt binders at very low temperatures. In summary, the use of waste seashells for recycling as bio-modifiers for asphalt binders is a practical approach.


2020 ◽  
Vol 12 (23) ◽  
pp. 10057
Author(s):  
Hyun Hwan Kim ◽  
Mithil Mazumder ◽  
Soon-Jae Lee ◽  
Moon-Sup Lee

In this study, thermoplastic polyurethane (TPU) and styrene-isoprene-styrene (SIS) were utilized to enhance asphalt binder properties. Superpave asphalt binder tests and multiple stress creep recovery (MSCR) were conducted to evaluate the physical and rheological performance (viscosity, rutting, and cracking properties) of the asphalt binders before and after short-term aging and after the long-term aging process. The results showed that (i) TPU has a positive effect on workability, including the mixing and compaction processes, which was evident from the reduced binder viscosity; (ii) asphalt binders with TPU and SIS showed better rutting resistance compared to the SIS binders without TPU; (iii) the cracking resistance of asphalt binders was found to be improved significantly with the addition of TPU; and (iv) TPU has the potential to be considered as a sustainable polymer modifier for producing bearable asphalt binders by improving rutting and crack resistance without increasing the melting temperature of the asphalt binders.


TRANSPORTES ◽  
2020 ◽  
Vol 28 (2) ◽  
pp. 76-86
Author(s):  
Luis Miguel Gutierrez Klinsky ◽  
Vivian Silveira dos Santos Bardini ◽  
Valeria Cristina De Faria

This study used the Multiple Stress Creep Recovery Test (MSCR) and the Flow number test to analyze the characteristics of asphalt rubber and its use in hot mix asphalt (HMA) regarding to their ability to withstand permanent deformation. MSCR tests were done in three commercial asphalt rubber and in the traditional asphalt binder 50/70. Flow number tests were performed in twenty four specimens of asphalt rubber mixtures and eight specimens of conventional asphalt mixtures. The results of these tests showed that all the asphalt rubber samples had lower compliance values (Jnr) in the MSCR test, which denotes that these modified binders improved the rutting resistance of HMA. This behavior was confirmed with flow number results, since the HMA produced with asphalt rubber had always higher flow number values, when compared to the conventional asphalt mixtures. The analysis of the data showed excellent correlation between Jnr values and FN values.


2019 ◽  
Vol 276 ◽  
pp. 03004
Author(s):  
Gabriel Skronka ◽  
Martin Jasso ◽  
Otakar Vacin

The sustainable use of non-renewable natural resources, such as asphalt binder, can be achieved by adequate planning. The proper assessment of asphalt binders is a prerequisite to the appropriate designing of road constructions that can eventually result in pavements in which the development of pavement distresses can be mitigated. Rutting is the most common distress occurring at high temperatures, which is frequently experienced by such countries as Indonesia; thus, the use of adequate asphalt binder in hot mix asphalt pavements results in long-lasting road constructions. By means of advanced techniques, e.g., multiple stress creep recovery test, conducted on a dynamic shear rheometer, it is possible to determine the rutting potential of asphalt binders. This technique, however, still seems to be imprecise at currently determined shear stress values. This paper aims to investigate on the example of ten different asphalt binders, if creep and recovery measured at higher shear stresses result in better correlation with rutting potential of hot mix asphalts than that at the standardized stress levels. Concurrently, other conventional asphalt binder properties (e.g., penetration, softening point, elastic recovery) are determined and compared with rutting.


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