A review on rejuvenating materials used with reclaimed hot mix asphalt

2020 ◽  
Author(s):  
Zaid Hazim Al Saffar ◽  
Haryati Yaacob ◽  
Mohd Khairul Idham ◽  
Mhmood Khleel Saleem ◽  
JAU CHOY LAI ◽  
...  
Keyword(s):  
Asphalt Pavement ◽  
Reclaimed Asphalt Pavement ◽  
Construction Technology ◽  
Reclaimed Asphalt ◽  
Aged Asphalt ◽  
Future Challenges ◽  
Materials Used ◽  
Pavement Construction ◽  
Optimal Approach ◽  
Pavement Service Life

In recent years, flexible pavement construction technology has relied heavily on the use of reclaimed asphalt pavement (RAP). However, the brittle nature of RAP, which stems from the use of an aged asphalt, has introduced numerous complexities into the process, with important implications to pavement service life. The properties of the aged asphalt can be rejuvenated to improve the performance and the behavior of RAP mixtures. This paper presents a review of past works that have used rejuvenating materials with RAP, including their benefits and drawbacks, as well as the optimal approach to increase RAP content in asphaltic mixtures. The method of rejuvenating aged asphalt and the mechanism of rejuvenation are also reviewed. The findings of this review can be used to predict the current and future challenges in the regeneration of RAP mixtures using rejuvenating materials.

scholarly journals A Review on the Durability of Recycled Asphalt Mixtures Embraced with Rejuvenators

2021 ◽  
Vol 13 (16) ◽  
pp. 8970
Author(s):  
Zaid Hazim Al-Saffar ◽  
Haryati Yaacob ◽  
Herda Yati Katman ◽  
Mohd Khairul Idham Mohd Satar ◽  
Munder Bilema ◽  
...  
Keyword(s):  
Asphalt Pavement ◽  
Climatic Conditions ◽  
Asphalt Mixtures ◽  
Reclaimed Asphalt Pavement ◽  
Extensive Literature ◽  
Recycled Asphalt ◽  
Reclaimed Asphalt ◽  
Traffic Loads ◽  
Aged Asphalt ◽  
Future Challenges

Reclaimed asphalt pavement (RAP) has received much attention recently due to its increased use in hot mix asphalt (HMA) pavements to enhance pavement sustainability. The use of aged asphalt in RAP, which is highly oxidised and has lost its properties due to exposure to traffic loads and climatic conditions throughout its lifespan, can cause asphalt mixtures to stiffen and embrittle, thus negatively affecting the behaviour of asphalt mixtures. This issue may be resolved by including rejuvenating agents that can restore both physical and rheological properties of aged asphalt by increasing maltene fractions and decreasing asphaltene. However, the high restoration capacity of any kind of rejuvenating agent does not assure the durability of restored aged asphalt. This study explored the performance and durability of rejuvenated asphalt mixtures embedded with several types of rejuvenators identified from the extensive literature review. The study serves as a significant reference to predict future challenges in rejuvenating aged asphalt.

Laboratory Investigation of Mixing Hot-Mix Asphalt with Reclaimed Asphalt Pavement

2005 ◽  
Vol 1929 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Baoshan Huang ◽  
Guoqiang Li ◽  
Dragan Vukosavljevic ◽  
Xiang Shu ◽  
Brian K. Egan
Keyword(s):  
Layered Structure ◽  
Hot Mix Asphalt ◽  
Coarse Aggregate ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Reclaimed Asphalt Pavement ◽  
Controlled Experiments ◽  
Reclaimed Asphalt ◽  
Aged Asphalt ◽  
Blending Process

This paper presents a laboratory study in which the blending process of reclaimed asphalt pavement (RAP) with virgin mixture was analyzed through controlled experiments. One type of screened RAP was blended with virgin (new) coarse aggregate at different percentages. A blended mixture containing 20% of screened RAP was subjected to staged extraction and recovery. The result from this experiment indicated that only a small portion of aged asphalt in RAP actually participated in the remixing process; other portions formed a stiff coating around RAP aggregates, and RAP functionally acted as “composite black rock.” The resulting composite layered structure was desirable to improve the performance of the hot-mix asphalt mixture.

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.

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