Asphalt is a mixture composed of hundreds of organic compounds. Based on solubility and polarity, asphalt can be divided into three parts. Asphaltenes are the most viscous and polar. Non-polar maltenes are mainly composed of aliphatic molecules and are the least viscous. Resin polarity and viscosity are in between those of asphaltene and maltene.

Asphalt can be used on road pavement in part because of its viscosity. Molecular simulations of viscosity are useful since they can distinguish among contributions from different compounds. First viscosities of some pure and small aromatic compounds were calculated via Green-Kubo expression and correlation functions. Then model asphalt mixtures comprised of three or more components were studied using atomic and molecular virial formulations of the stress tensor. Viscosity of asphalt mixture having a polymer was also studied.Finally, time-temperature superposition theory was used to see if those results are reasonable.