UC Pavement Research Center
Available online at https://doi.org/10.1061/JPEODX.0000004
Coleri, Erdem and John T. Harvey (2017) Impact of Pavement Structural Response on Vehicle Fuel Consumption. Journal of Transportation Engineering, Part B: Pavements 143 (1), 04017002
In this study, vehicle energy consumption induced by the viscous behavior of asphalt pavement materials was calculated by using 3D viscoelastic finite-element (FE) modeling. Five pavement structures with conventional, rubber, and polymer-modified asphalt overlay mixes with old asphalt, cracked concrete, and cement treated base (CTB) underlying layers were modeled to evaluate the impact of structure type on calculated excess fuel consumption (EFC). A fully loaded 18-wheel tractor-trailer was simulated. EFC was defined as the fuel consumption beyond what occurs for an ideal pavement with no energy consumed due to structural response. A total of 234 FE models for a full factorial design were developed to simulate the impact of three speed levels (8, 52, and 105 kph), two subgrade stiffnesses (50 and 200 MPa), and nine temperatures (0–80°C at 10°C intervals) on calculated EFC. Results show that the greatest EFC is primarily observed at pavement temperatures higher than 40°C. For an average truck highway speed of 97 kph, average pavement temperatures for three cities in California (Daggett, Sacramento, and San Francisco) resulted in excess fuel consumptions ranging from 0.1 to 0.35% for the structures analyzed in this study. Although this level of EFC appears to be much less than typical roughness related EFC, models for EFC due to structural response can aid in decision-making processes, particularly in cases in which models show it to be greatest. Polymer-modified overlays were observed to have the highest EFC when compared with other structures. Having a concrete layer or a CTB layer under the asphalt overlay rather than having an aged asphalt layer did not create any significant reduction in EFC. Subgrade stiffness was also not observed to be a significant factor affecting EFC.
Keywords: excess fuel consumption; viscoelasticity; energy dissipation; pavement; asphalt; finite-element modeling