Impact of Concrete Pavement Structural Response on Rolling Resistance and Vehicle Fuel Economy

Reduction in vehicle fuel consumption is one of the main benefits considered in technical and economic evaluations of road improvements. The study described in this paper investigated the increase in vehicle energy consumption caused by the structural response of a concrete pavement to a moving load. First, the day and night falling weight deflectometer deflection time histories were measured for three concrete sections; their mechanical characteristics were then backcalculated. Second, a finite element model (DYNASLAB) was used to determine the pavement structural response under moving load for all three sections under different wheel loading conditions (passenger car, SUV, and articulated truck), vehicle speeds, and temperatures. As the rolling wheels move forward, the local deflection basin caused by the delayed deformation of the subgrade and the rotation of the slab form a positive slope. The energy dissipated was calculated as the energy required for a rolling wheel to move uphill. Finally, the calorific values of gasoline and diesel were used to convert energy into fuel consumption excess. The maximum deflection-induced energy consumption is about 0.08% of the total consumption for articulated trucks, which is small compared with 1.9% for asphalt pavements at high temperatures and low speeds, as reported by other studies.