Loading...

Characterization of RAP Binder and Warm Mix Asphalt Containing High RAP Percentage and Crumb Rubber

Morsali, Atefeh | 2015

712 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 47332 (09)
  4. University: Sharif University of Technology
  5. Department: Civil Engineering
  6. Advisor(s): Tabatabaei, Nader
  7. Abstract:
  8. Increased environmental concerns and high oil prices have encouraged highway agencies to maximize the use of recycled materials like Reclaimed Asphalt Pavements (RAP) in pavement construction. However, utilization of RAP has limited to low percentage, generally less than 25%. This is due aged, stiffer, and less strain tolerant asphalt binder in RAP. As the RAP proportion increases, a large amount of the aged binder will be introduced into the mixture. The excessive stiffness of HMA mixture tends to lead to less workable mixture. Studies were conducted to examine the effect of Sasobit on the workablility of high RAP mixtures. The results indicated while the utilization of Sasobit had improved the workability of mixtures, the resistance to moisture damage of RAP mixture decreased. Therefore, it is necessary to evaluate the effect of different additives on workability and moisture succeptibility of high RAP mixtures. The objective of this study was to investigate the influence of engineering properties of Crumb Rubber (CR), Sasobit Warm Mix Asphalt (WMA) technology and Hydrated Lime (HL) on the rheological properties of composite binder of Reclaimed Asphalt Pavements (RAP) and virgin binder. Further, the effect of these additives on the performance of high RAP mixture was evaluated. For this purpose, RAP mixtures were prepared using different percentage of CR and Sasobit, with and without Sasobit and hydrated lime, respectively, and then tested for workability and moisture susceptibility. The result indicated that all the modified virgin binders except Sasobit aided one had improved reological properties of RAP binder. Based on moisture induced damage test, the introduction of RAP to warm mix asphalt had decreased the resistance of mixture against moisture. Considering the workability, moisture susceptibility, and asphalt binder test data, Sasobit and HL combination is the best additives in high RAP mixture. The data also indicated that the RAP mixtures with CR modified virgin binder on average tended to exhibit a lower workability than the RAP mixture with unmodified virgin binder, but the difference were not statistically significant
  9. Keywords:
  10. Reclaimed Asphalt Pavement (RAP) ; Crumb Rubber Modifier ; Sasobit ; Hydrated Lime ; Efficiency ; Moisture Susceptibility ; High Reclaimed Asphalft Pavements (RAP)Content Mixture

 Digital Object List

 Bookmark