Viscous Energy Dissipation in Asphalt Pavement Structures and Implication for Vehicle Fuel Consumption

The present paper deals with the energy dissipation induced by the viscous behavior of bituminous materials constituting pavement. An approach to take into account viscous properties of bituminous layers and to quantify this dissipation is explained. First, the behavior of different bituminous materials is investigated. Linear viscoelastic modeling is then proposed using a rheological model previously developed at the Civil Engineering and Buildings Department (DGCB) of the University of Lyon / ENTPE (Ecole Nationale des Travaux Publics de l’Etat). Second, this model is implemented in a finite-element code, which enables simulation of the behavior of any pavement structures under any rolling load. In this paper, these developments, previously validated for orthotropic steel bridge and mix surfacing structures, are applied on a classical French pavement structure. In addition, the calculation of energy dissipation due to the viscous properties of the bituminous materials is allowed. Then an estimation of corresponding fuel consumption excess is given considering a 40-ton truck for different temperatures and speeds. The influence of the base course thickness is investigated as well. The simulation results show that energy dissipation in bituminous pavement due to the rolling weight of the considered 40-ton truck may induce a fuel consumption excess of a few percents age points in very unfavorable climatic conditions.