Properties of Rejuvenated RAPs from Stone Mastic Asphalt

2017 ◽  
Vol 863 ◽  
pp. 129-134
Author(s):  
Petr Hyzl ◽  
Iva Krcmova ◽  
Pavla Nekulova ◽  
Ondrej Dasek ◽  
Pavel Coufalik
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Chemical Properties ◽  
Asphalt Binders ◽  
Reclaimed Asphalt ◽  
Mastic Asphalt ◽  
Aged Asphalt ◽  
Stone Mastic Asphalt ◽  
The Individual ◽  
Physical And Chemical

Recycling asphalt pavement creates a cycle of reusing materials that optimizes the use of natural resources. Reclaimed asphalt pavement (RAP) is a useful alternative to virgin materials because it reduces the need to use virgin aggregate. This paper is concerned with the current issue of using RAP in Stone Mastic Asphalt (SMA). SMA is a wearing course, which is especially stable and durable. It describes the effects of application of rejuvenators on properties of asphalt binders. These rejuvenation additives restore the physical and chemical properties of aged binders. In addition, the aged asphalt binder with rejuvenators applied was subjected to a short-term laboratory aging using the RTFOT (Rolling Thin Film Oven Test). To assess the binder properties, both the standard empirical tests and more advanced functional tests (dynamic shear rheometer and bending beam rheometer) have been performed. Last part of the paper provides an evaluation of the individual rejuvenation additives. Based on the results it can be concluded that a positive change in properties of aged asphalt binder obtained from a modified RAP (from SMA) after applying all the rejuvenators has been proven. The effect of the rejuvenators during the manufacturing process and laying has been verified.

Use of Rejuvenators to Rejuvenate Asphalt Binders in RAP

2017 ◽  
Vol 737 ◽  
pp. 547-553
Author(s):  
Iva Krcmova ◽  
Petr Hyzl ◽  
Pavla Nekulova ◽  
Pavel Coufalik ◽  
Ondrej Dasek
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Chemical Properties ◽  
Asphalt Binders ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Aged Asphalt ◽  
Empirical Tests ◽  
The Individual ◽  
Physical And Chemical

With increased demand and limited aggregate and binder supply, hot mix asphalt (HMA) producers discovered that reclaimed asphalt pavement (RAP) is a valuable component in HMA. This paper is concerned with the current issue of higher using RAP (Reclaimed Asphalt Pavement) in asphalt mixtures for pavement wearing courses. It describes the effects of application of three types of rejuvenation additives on properties of aged asphalt binders made from a regular RAP. These rejuvenation additives restore the physical and chemical properties of aged binders. In addition, the aged asphalt binder with rejuvenators applied was subjected to a short-term laboratory aging using the RTFOT (Rolling Thin Film Oven Test). This method simulate aging asphalt binder during the manufacturing process and laying. To assess the binder properties, both the standard empirical tests and more advanced functional tests (dynamic shear rheometer and bending beam rheometer) have been performed. Last part of the paper provides an evaluation of the individual rejuvenation additives. Based on the results it can be concluded that a positive change in properties of aged asphalt binder after applying all the three rejuvenators has been proven.

The Applicability of Estimated Equations of Recycling Agents on the Viscosity Variety of Aged Asphalt Binders

2013 ◽  
Vol 723 ◽  
pp. 670-677 ◽  
Author(s):  
Ping Sien Lin ◽  
Chi Wen Chang ◽  
Tung Lin Wu
Keyword(s):  
Asphalt Binder ◽  
Asphalt Binders ◽  
Apparent Effect ◽  
Reclaimed Asphalt ◽  
Aged Asphalt

This study was to perform the viscosity test of adding different ratios (from 10% to 40%) of three recycling agents (RAs), namely RA25, RA75 and RA250, to the reclaimed asphalt binder (RAB) containing a viscosity of 42800 poises. The purpose of the study was to determine the effects of various RAs on the viscosity of aged asphalt binders. The viscosity values were also estimated based on the recycling model of aged asphalt binder developed by authors and the equations developed by Arrhenius (1887), Grunberg and Nissan (1949) and Epps et al. (1980). The results show that there are significant variations in the viscosity of recycling asphalt binder when being added different ratios of RA. The estimated viscosity values computed by the recycling model of aged asphalt binder are closer to the tested results when compared with the equations developed by Arrhenius (1887), Grunberg and Nissan (1949) and Epps et al. (1980). Furthermore, the Recycling Index (RI) developed by the recycling model of aged asphalt binder can clearly and precisely reveal the recycling performance of different kinds of RAs. The Gmix from the equation developed by Grunberg and Nissan (1949) has an apparent effect on estimating the viscosity when adding RA to the RAB.

Relationships among Chemistry, Rheology, and Fracture/Fatigue Performance of Recovered Asphalt Binders and Asphalt Mixtures Containing Reclaimed Asphalt Pavement

2020 ◽  
Vol 2674 (10) ◽  
pp. 927-938
Author(s):  
Peyman Barghabany ◽  
Wei Cao ◽  
Louay N. Mohammad ◽  
Samuel B. Cooper ◽  
Samuel B. Cooper
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Intermediate Temperature ◽  
Asphalt Binders ◽  
Rheological Parameters ◽  
Cracking Resistance ◽  
Reclaimed Asphalt ◽  
Four Point Bending

Because of limited amounts of natural resources, reclaimed asphalt pavement (RAP) has gained popularity in the asphalt pavement industry to meet sustainability requirements in asphalt pavement. Concerns have been raised in relation to the intermediate temperature cracking performance of asphalt mixtures containing RAP. The objective of this study was to evaluate the intermediate temperature cracking resistance of asphalt mixtures and recovered asphalt binders containing RAP. Seven plant-produced asphalt mixtures from three transportation agencies with various RAP contents and the extracted asphalt binders were evaluated with respect to intermediate temperature cracking resistance. Asphalt binder experiments included chemical and rheological characterization of recovered asphalt binders. Chemical characterization consisted of Fourier transform infrared spectroscopy and saturates/aromatics/resins/asphaltenes component analysis. Linear amplitude sweep and time sweep tests were also performed to characterize the rheological properties of asphalt binders. Asphalt mixture experiments included four-point bending beam fatigue and semi-circular bend tests. Results indicated that, as expected, asphalt mixtures with high RAP contents resulted in asphalt binders and mixtures with reduced cracking resistance. Relationships between the asphalt binder chemical and rheological parameters and asphalt mixture cracking resistance were also investigated. Asphalt binder rheological and chemical parameters were well correlated. Asphalt binder rheological parameters showed reasonable to strong relationships with the four-point bending beam fatigue test result. The work presented in this paper is part of FHWA Transportation Pooled Fund Project TPF-5(294) “Develop Mix Design and Analysis Procedure for Asphalt Mixtures Containing High RAP and/or RAS Contents.”

Impact of Recycled Materials and Recycling Agents on Asphalt Binder Oxidative Aging Predictions

2018 ◽  
Vol 2672 (28) ◽  
pp. 277-289 ◽  
Author(s):  
Sara Pournoman ◽  
Elie Y. Hajj ◽  
Nathan Morian ◽  
Amy Epps Martin
Keyword(s):  
Asphalt Binder ◽  
Asphalt Binders ◽  
Complex Nature ◽  
Recycled Asphalt ◽  
Recycled Materials ◽  
Reclaimed Asphalt ◽  
Oxidative Aging ◽  
Cracking Potential ◽  
Binder Oxidation ◽  
The Individual

The overall objective of this study was to evaluate the influence of selected recycling agents (RAs) and recycled materials on the development of cracking potential with respect to oxidative aging. Given the complex nature of varying base asphalt binders, recycled materials, whether recycled asphalt pavement (RAP), reclaimed asphalt shingles (RAS), or both, and the complexity of their combined interactions with recycling agents, standard evaluation protocols for binder grading and evaluation may be insufficient. The binder blend aging predictions or oxidation modeling evaluation was introduced as a means to evaluate the combined influence of both binder oxidation kinetics and resulting rheological changes on the measured cracking potential of the various binder blends—that is, Glover–Rowe (G-R) parameter—driven by temperature estimation modeling over simulated in-service durations at example geographic locations. This evaluation has demonstrated the importance of adequate characterization of the specific materials being used in conjunction with selection of the correct dose of the appropriate recycling agent to ensure sufficient resistance to cracking and embrittlement of proposed material combinations. The combined influence of all the interested components did not always add up to the sum of the individual parts, nor are the measured interactions consistent with increased levels of oxidation. Therefore, the prevailing conclusion of the study as a whole indicated that material-specific evaluations are needed to identify the complex interactions taking place within the material combinations of interest, but also multiple levels of aging at appropriate intervals may be necessary for comprehensive characterization.

scholarly journals Interactions between RAP and virgin asphalt binders in field, plant, and lab mixes

2022 ◽  
Vol 13 (1) ◽  
pp. 231-249
Author(s):  
Eslam Deef-Allah ◽  
Magdy Abdelrahman
Keyword(s):  
Asphalt Binder ◽  
Chemical Properties ◽  
The United States ◽  
Asphalt Binders ◽  
Creep Recovery ◽  
Reclaimed Asphalt Pavement ◽  
Asphalt Mixes ◽  
Reclaimed Asphalt ◽  
Multiple Stress Creep Recovery ◽  
Materials Used

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.

Effects of Preheating on the Rheological Properties of Rejuvenated Asphalt Binder

2019 ◽  
Vol 2673 (4) ◽  
pp. 546-557 ◽  
Author(s):  
Yang Liu ◽  
Hainian Wang ◽  
Susan Tighe ◽  
Guangyuan Zhao ◽  
Zhanping You
Keyword(s):  
Rheological Properties ◽  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Fatigue Properties ◽  
Dynamic Shear ◽  
Recycled Asphalt ◽  
Reclaimed Asphalt ◽  
Aged Asphalt ◽  
Asphalt Materials

Hot in-place recycling (HIR) is a process that reuses reclaimed asphalt materials to benefit the environment and conserve natural resources. HIR has not yet been widely applied in China because of technical drawbacks such as reclaimed materials’ fatigue properties and poor cracking resistance. Preheating is the first procedure in HIR and significantly affects the diffusion of rejuvenators within the aged asphalt and the remixing of virgin and aged mixtures. This study focuses on the effects of preheating on the rheological properties of rejuvenated asphalt binder using dynamic shear rheometer (DSR) testing. Three types of rejuvenators (Reju-A, Reju-B and Reju-C), three types of base asphalt binder (#50, #70, and #90), recovered asphalt from recycled asphalt pavement, and laboratory-aged asphalt were investigated to analyze the rheological properties under different heating conditions. The results show that (1) rejuvenators contain little in the way of viscous characteristics and have a viscosity-reducing effect on aged asphalt; (2) field-aged asphalt loses cohesion and gains rutting resistance during aging; and (3) preheating has a significant effect on diffusion of rejuvenators within aged asphalt as well as on rheological properties. In short, a good controlled preheating operation is critical to the quality of the asphalt rejuvenation process.

Synthesis of Cu2O and ZnO Nanowires and their Heterojunction Nanowires by Thermal Evaporation: A Short Review

2014 ◽  
Vol 71 (5) ◽  
Author(s):  
Muhammad Arif Khan ◽  
Samsudi Sakrani ◽  
Syahida Suhaima ◽  
Yussof Wahab ◽  
Rosnita Muhammad
Keyword(s):  
Physical Vapor Deposition ◽  
Thermal Evaporation ◽  
Chemical Properties ◽  
High Sensitivity ◽  
Short Review ◽  
Zno Nanowires ◽  
Oxide Semiconductor ◽  
The Individual ◽  
Photovoltaic Solar Cells ◽  
Physical And Chemical

One dimensional metal oxide semiconductor nanowires of copper (I) oxide (Cu2O), zinc oxide (ZnO), and their heterojunction nanowires possess remarkable physical and chemical properties. ZnO and Cu2O areattractive because the metals are abundant on earth, inexpensive, nontoxic.Moreover, these oxides have useful optical and electrical properties suitable for a wide variety of electrical devices, because their electrical conduction can be predictably controlled by doping. We here restrict the disscussion using a Hot Tube Vacuum Thermal Evaporation. The NWs in these devices will be studied by physical vapor deposition known as vapor-liquid-solid (VLS). Therefore, we explore conventional methods, particularly the VLS of growing ZnO and Cu2O nanowires which are assisted by the catalyst.  In this short review, we report the individual and combined (Cu2O/ZnO) junction nanowires by PVD method.  The main advantages of these composite nanowires are the natural p-n characteristics, the broad light absorption, the high sensitivity to humidity changes, and the fast dynamic response. The combination of all characteristics offered by Cu2O/ZnO nanowires can enable the fabrication of diverse sensing devices, and photovoltaic solar cells.

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