Rheology of Fractionated Cornstover Bio-oil as a Pavement Material

Most bituminous binders that are used for pavement materials are derived from fossil fuels. Recently, different vegetable oils have been investigated to study their applicability to be used as bio-binders, which can be used in three different ways: a direct alternative binder (100% replacement), a bitumen extender (25% to 75% bitumen replacement), or a bitumen modifier (<10% bitumen replacement). In this paper, the rheological properties of bio-oils derived from cornstover (non-food source) have been investigated to determine the applicability of developing bio-binders as an alternative to asphalt derived from crude petroleum. The rheological properties included the shear and temperature susceptibilities and the aging index. The results show that the temperature is the main contributor to change the viscosity of the unmodified and modified cornstover bio-oil. As an overall conclusion, the rheological properties of cornstover bio-oils are similar and comparable to bitumen binders and represent a renewable alternative to petroleum derived asphalt binders.