Loading...

Rheological Evaluation of Ageing Properties of Modified Bitumens

Naderi, Koorosh | 2010

677 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 42039 (09)
  4. University: Sharif University of Technology
  5. Department: Civil Engineering
  6. Advisor(s): Tabatabaee, Nader
  7. Abstract:
  8. Bitumen ageing is one of the principal factors causing the deterioration of asphalt pavements. Ageing is a complex process that is affected by different parameters.With the rapid growth of modified binders in road paving applications over the past twodecades, it is important to study the ageing properties of these binders. A number of laboratory methods are used tosimulatethe bitumenageing at various stages of the production and service of hot mix asphalt.Recent studies have shown that Superpave testing protocol does not fully address the ageing of modified binders. To study the ageing properties of modified binders, three different types of binder modifiers, plastomer, elastomer, and ground tire rubber were selected. Simulated ageing resulted in overall hardening of the unmodified binder as marked by broadening of the relaxation spectra. Ageing of the modified binders, however, strongly depends on type and concentration of modifiers as well as the method of ageing simulation used. To overcome the problems that have been encountered in rolling thin film oven test, SAFT apparatus was built and used for laboratory evaluation of modified binder ageing. SAFT aged binders showed similar performance grading as those RTFOT aged binders. Furthermore, binder spillage did not happen during SAFT aging, when modified binders were used. Comparing the rheological data of the long-term binder ageing done by the environmental room conditioning (EIC) simulation to that of PAV indicates that PAV ageing may result in breakdown of polymer network in the modified binders and does not properly simulate the long-term field aging of modified binders.
  9. Keywords:
  10. Viscoelastic Behavior ; Aging ; Modified Bitumen ; Stirred Airflow Test (SAFT) ; Relaxation Spectrum ; Rheological Model

 Digital Object List

 Bookmark

No TOC