Investigation of Hot-Mix Asphalt Dynamic Modulus by Means of Field-Measured Pavement Response

Abstract

The current Mechanistic–Empirical Pavement Design Guide (MEPDG) proposes the use of the laboratory dynamic modulus test to determine time–temperature-dependent properties of hot-mix asphalt (HMA) materials. To date, limited measurements have been performed to compare the HMA behavior of laboratory dynamic modulus test with the field measured pavement response. The objectives of this study were to compare and validate laboratory-determined HMA dynamic modulus with field-measured asphalt longitudinal strains. Under constant loading frequency, the laboratory-determined dynamic modulus for Hot Laid 3 (HL3) was found to decrease exponentially when the temperature of the asphalt mix increased. Controlled wheel load experiments, performed at a constant truck speed, found that HL3 asphalt longitudinal strain increased exponentially with an increase in asphalt middepth temperature. The comparison of both exponential relationships showed that the laboratory-determined dynamic modulus was inversely proportional to the field-measured asphalt longitudinal strain.