Evaluation of the chemical composition and rheological properties of bio-asphalt from different biomass sources

Abstract

This paper presents the findings of a study conducted to evaluate the potential effect of bio-asphalt from corn and wood waste on the rheological properties of styrene–butadiene–styrene/rubber composite-polymer modified asphalt. Results showed that bio-asphalt from corn contained significantly high amount of oxygen (62%), whereas petroleum-based asphalt only contained trace amounts of oxygen (0.91%). The average molecular weight, total rings per average molecule, naphthenic carbon rate, and aromaticity of bio-asphalt from corn were smaller than that of petroleum-based asphalt. Meanwhile the characteristics of bio-asphalt from wood waste were similar to that of petroleum-based asphalt, yet the molecular size and polarity of bio-asphalt were slightly lower. For workability, the addition of bio-asphalt decreases the viscosities of composite-polymer modified asphalt. Samples with bio-asphalt from wood waste presented higher viscosity than that with bio-asphalt from corn at the same added amount. A suitable amount (15%) of bio-asphalt showed the best anti-rutting properties under all conditions owing to bio-asphalt can function as light oil to swell polymer or act as a lubricant to limit the intermolecular interactions. Moreover, the addition of bio-asphalt from corn increased the anti-cracking property, whereas the increasing degree of adding bio-asphalt from wood waste were not obvious. The m-values of samples with bio-asphalt from wood waste were also smaller than that of samples added with bio-asphalt from corn. The stiffness of modified asphalt with bio-asphalt from wood waste decreased with an added amount of less than 15% and increased when the bio-asphalt amount exceeded 15%. Samples with bio-asphalt from wood waste also provided better durability and storage stability than that with bio-asphalt from corn. Therefore, bio-asphalt from wood waste was more suitable to represent petroleum-based asphalt partly than bio-asphalt from corn.

Keywords:

• asphalt
• bio-asphalt
• polymer modification
• chemical composition
• rheological properties

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by National Science Foundation of China [51268031], which was aimed at the research of new technology of road material.