Effects of Preheating on the Rheological Properties of Rejuvenated Asphalt Binder

Author(s):  
Yang Liu ◽  
Hainian Wang ◽  
Susan Tighe ◽  
Guangyuan Zhao ◽  
Zhanping You

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.

2014 ◽  
Vol 638-640 ◽  
pp. 1185-1189
Author(s):  
Tan Hua

To explore the effects of different factors on the rheological properties of cariphalte modified asphalt, based superpave asphalt binder relevant norms, through the use of dynamic shear rheometer Shell 70# asphalt under different temperature, frequency and strain conditions and rheological properties of cariphalte modified asphalt carrying on a systematic study, and comparative analysis of the two anti-fatigue properties of asphalt in the middle and low temperature.The results show that: compared with 70# asphalt, cariphalte modified asphalt has better rutting resistance over a wide temperature range; at lower frequencies and high intensity pavement, cariphalte modified asphalt to better resistance to permanent deformation; better fatigue resistance at low temperatures, and more fatigue damage is not easy to achieve.


2017 ◽  
Vol 737 ◽  
pp. 547-553
Author(s):  
Iva Krcmova ◽  
Petr Hyzl ◽  
Pavla Nekulova ◽  
Pavel Coufalik ◽  
Ondrej Dasek

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.


2019 ◽  
Vol 220 ◽  
pp. 187-195 ◽  
Author(s):  
Sharareh Shirzad ◽  
Marwa M. Hassan ◽  
Max A. Aguirre ◽  
Louay N. Mohammad ◽  
Samuel Cooper ◽  
...  

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.


2021 ◽  
Vol 11 (12) ◽  
pp. 5698
Author(s):  
Jian Zhou ◽  
Jing Li ◽  
Guoqiang Liu ◽  
Tao Yang ◽  
Yongli Zhao

Increasing the content of reclaimed asphalt pavement material (RAP) in hot-mix recycled asphalt mixture (RHMA) with a satisfactory performance has been a hot topic in recent years. In this study, the performances of Trinidad lake asphalt (TLA), virgin asphalt binder, and aged asphalt binder were first compared, and then the modification mechanism of TLA on virgin asphalt and aged asphalt was explored. Furthermore, the RHMA was designed in accordance with the French norm NF P 98-140 containing 50% and 100% RAP, and their high-temperature stability, low-temperature cracking resistance, and fatigue performances were tested to be compared with the conventional dense gradation AC-20 asphalt mixture. The results show that the addition of TLA changes the component proportion of virgin asphalt binder, but no new functional groups are produced. The hard asphalt binder modified by TLA has a better rutting resistance, while the fatigue and cracking resistance is lower, compared to both aged and virgin asphalt. The high-modulus design concept of RHMA is a promising way to increase the RAP content in RHMA with acceptable performance. Generally, the RHMA with 50% RAP has similar properties to AC-20. And, when the RAP content reaches 100%, the high- and low-temperature performance and anti-fatigue performance of RHMA are better than AC-20 mixture. Thus, recycling aged asphalt using hard asphalt binder for hot-mixing recycled asphalt mixture to increase the RAP content is feasible.


2021 ◽  
Vol 13 (19) ◽  
pp. 10938
Author(s):  
Nathanyawat Sedthayutthaphong ◽  
Peerapong Jitsangiam ◽  
Hamid Nikraz ◽  
Suriyavut Pra-ai ◽  
Sarintip Tantanee ◽  
...  

The application of asphalt hot mix recycling is one challenge in sustainable road pavement research. In addition to the vast amount of research on the performance of recycled asphalt–concrete, the research on the frictional resistance of recycled hot mix asphalt is still limited. The effects of aged asphalt and aged aggregates on the skid resistance of recycled hot mix asphalt were investigated in this research. The aged asphalt and aged aggregates were carefully extracted from the field-reclaimed asphalt pavement, and the engineering and mechanical properties of aged and virgin aggregates were measured. The degradation of recycled hot mix asphalt was simulated using an accelerated polishing machine to mimic road surface abrasion. Accordingly, the initial and final skid resistances of the recycled hot mix asphalt were determined and correlated with the properties of the aged asphalt and aggregates. The initial skid resistance of recycled hot mix asphalt decreased with reductions in penetration and ductility of the blended asphalt. However, the changes in the blended asphalt properties contributed only small variations to the final skid resistances of the recycled hot mix asphalt. The gradations of recycled hot mix asphalt correlated only with the final skid resistances. The aggregate gradations controlled the characteristics of the final skid resistance since the covered binder was partially polished off from the road surface at this stage.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Ben Liu ◽  
Junan Shen ◽  
Xuyan Song

Aging of an asphalt binder causes the changes in the microstructure and, consequently, in the nanomechanical and rheological properties of the aged asphalt binder. Short-term aging on asphalt binders was simulated using rotating thin film oven (RTFO). These changes in the microstructure and nanomechanical and rheological properties were measured using atomic force microscope (AFM) and dynamic shear rheometer (DSR). The results indicated that (1) the adhesive force of the asphalt binder from AFM tests was increased after RTFO aging; (2)G*of the asphalt binder from DSR tests increased after RTFO aging; (3) the results from AFM were consistent with those from DSR, explaining the mechanism of the changes of rheological properties.


2017 ◽  
Vol 863 ◽  
pp. 129-134
Author(s):  
Petr Hyzl ◽  
Iva Krcmova ◽  
Pavla Nekulova ◽  
Ondrej Dasek ◽  
Pavel Coufalik

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.


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