Study of Rheological and Creep Recovery Properties of Asphalt Binder Modified with Waste Toner

Large quantities of waste toner (WT) are generated annually either due to the incessant manufacturing process or from copying machines. Disposal of WT is primarily in landfills, which deteriorates the environment. This study attempts to overcome this predicament by utilizing WT for asphalt pavement construction by means of incorporating it in asphalt binder. The effect of WT on rheological properties of asphalt binder was explored in this research. An unmodified asphalt binder AC30 was adopted and modified with three contents of WT (7%, 14%, and 21% by weight). Tests including high-temperature performance grade (PG), temperature sweep, frequency sweep, and multiple stress creep and recovery (MSCR) were performed in this study. Mixing and compaction temperature was observed to marginally increase on introduction of WT. The addition of WT was perceived to cause a bump in high-temperature PG of AC30 binder. Improvement in rutting resistivity of AC30 binder was recorded. However, a degradation of fatigue resistance was observed. Master curves indicated an enhancement in complex shear modulus ($|G^{*}|$) and reduction in phase angle ($\delta$) at low frequencies due to incorporation of WT. However, at higher frequencies, convergence of the curves was observed. MSCR analysis indicated that WT addition enhanced percent recovery ($R$) and decreased nonrecoverable creep compliance ($J_{nr}$). Overall, the addition of WT was observed to cause changes in the rheological behavior of AC30 binder and an improved resistance to rutting at high temperature.