Fractional Viscoelastic Study of Low-Temperature Characteristics of Biomodified Asphalt Binders: Fid-Bau Portal

Fractional Viscoelastic Study of Low-Temperature Characteristics of Biomodified Asphalt Binders

Fini, Ellie H. / Khodaii, Ali / Hajikarimi, Pouria

Low-temperature cracking in pavement is a common distress in cold regions especially in North America; such distresses are shown to be highly related to binder low-temperature properties. To reduce the low-temperature cracking, several state departments of transportation are requiring the use of polymer-modified asphalt. However, polymer modification tends to be costly and in some cases led to phase separation in asphalt. Therefore, the current paper implements a fractional viscoelastic approach to study the effectiveness of several bio-based modifiers on improving asphalt binder’s low-temperature characteristics. As such, implementing the bending beam rheometer (BBR) test, low-temperature rheological characteristics of asphalt binders, which are modified by four different bio-oils including biobinder from swine manure, corn stover, wood pellet, and miscanthus pellet are investigated. For this purpose, the BBR test was performed on asphalt binder samples containing 10% modifier at three temperatures of $- 12$ , $- 18$ , and $- 24 ° C$ . In order to analyze results of the BBR test, a fractional viscoelastic model is used to describe the relation of creep compliance and time. Utilizing the simple fractional model, relaxation modulus, storage modulus, and loss modulus are derived. In addition to the Superpave performance grading (PG) protocol, parameters of the simple fractional viscoelastic model are used to evaluate the performance of asphalt binders at low service temperatures through damping ratio and dissipated energy ratio. While biobinder from swine manure has the best performance by Superpave PG protocol analysis, corn stover shows the highest values for damping ratio and dissipated energy ratio among all modified asphalt samples.