Aging Evaluation of Amorphous Carbon-Modified Asphalt Binders Using Rheological and Chemical Approach

Like every other organic compound, asphalt binder experiences aging over time, which significantly affects its chemical and physical properties. This study was the extension of a series of previous research studies in an attempt to evaluate the amorphous carbon-modified binders as a byproduct of paraffin factory when added in asphalt binder. A novel approach was taken in this research study to evaluate the aging properties of amorphous powder. Historically, it is believed that carbon powder can improve the aging of asphalt binder; however, the methods for such a claim are not designed well for long-term evaluation. This study used a time-temperature-aging superposing principle that added an aging component to the well-known time-temperature superposition principle to evaluate the aging properties of amorphous-modified binders comprehensively. This methodology was verified with a chemical test, Fourier-transform infrared (FTIR) spectroscopy. The master curve results, along with chemical properties, showed as binder aged, the rate of aging decreased. The chemical results indicated the benefits of amorphous powder against aging to some extent; however, due to added stiffness of this powder that acted as filler in binder, the master curve of aging showed higher stiffness values for samples modified with 10% amorphous carbon compared to 5% and 0% binders.