Toward Sustainable Asphaltic Materials: A Molecular Dynamics (MD) Investigation of Bio-oil Modified Asphalt*

We have investigated the behavior of a novel asphaltic material obtained by adulterating a model asphalt system¹ with a rationally selected foreign species of bio-oil. A wide range of systems is modeled by MD simulations featuring a systematic combination of modifier type, modifier concentration, and temperature. The mobility and structural integrity of the proposed materials were investigated in addition to mechanical response prediction by use of moduli calculations. The need to resolve issues of processability such as phase separation of commonly used modifiers, for example scrap tire², represents an important impetus for the current project. A case is made whereby the molecular observations made in the proposed modified asphalt systems indicate a maintenance of or improvement over essential macro functionalities of pristine asphalt. The replacement of a significant proportion of traditional asphalt by bio-oils constitutes a move toward green construction materials by allowing for less use of bitumen, a byproduct in heavy oil refineries implicated in pollution.
References:
1. Liqun Zhang and Michael L. Greenfield Energy & Fuels, 2008 22 (5), 3363-3375
2. Fini, Ellie H., et al. Journal of Environmental Engineering, 2013, 1454-1461