Resilient Modulus Characterization of Alaska Granular Base Materials

The resilient modulus (M_R) of base course material is an important material input for pavement design. Although extensive research efforts have been directed toward M_R characterization and modeling, less effort has been spent on factors important for cold-region pavements. Most M_R values of granular base materials available in the database of the Alaska flexible pavement design software were obtained from in-service roadways through nondestructive testing and backcalculation. The predictive models provided in the current Mechanistic–Empirical Pavement Design Guide cannot be confidently applied to Alaska materials because of the peculiar conditions for material properties and climatic differences. Hence, a systematic study was carried out to investigate the resilient behavior of granular base materials obtained from all three regions in Alaska, as presented in this paper. Effects of temperature, freeze–thaw cycle, and moisture and fines contents on the M_R of Alaska base materials were experimentally evaluated, from which equations for M_R prediction were developed and compared with those based on the Long-Term Pavement Performance data.