Characterization of rheological properties and aging performance of bitumen modified by bio-oil from bamboo charcoal production

As a waste stream from charcoal production, the liquid bio-oil has not been properly used, leading to both environmental and economic issues. In this study, this deleterious waste was explored as a promising additive for petroleum-based bitumen. Raw bio-oil was pretreated through distillation under different temperature to remove undesirable components. The resulting medium and heavy bio-oil fractions were blended with petroleum-based bitumen by weight ratios up to 12% to obtain bio-bitumen. The rheological and aging properties of the bio-bitumen were further evaluated with various test means. The results showed that the addition of bio-oil had softening effect on bitumen. Bio-bitumen performed better brittleness resistance with smaller Glover-Rowe parameters and better fatigue crack resistance at shorter crack length than that of base bitumen. The lower non-recoverable creep compliance of the heavy fraction modified bio-bitumen indicated its better rutting resistance, compared to that of the base bitumen. Characterization of the carbonyl and sulfoxide functional groups in the aged bitumen showed comparative aging performance of the bio-bitumen modified with heavy fraction. The findings of this study indicate that the promising potential of bio-oil heavy fraction to replace petroleum-based bitumen for generating sustainable road paving material.