Materials and Temperature Effects on the Resilient Response of Asphalt-Treated Alaskan Base Course Materials

摘要

Asphalt-treated bases (ATBs) are the most commonly used type of stabilized layer in Alaska because of locally available asphalt resources and its relatively lower cost. As an essential material input parameter for pavement design, resilient modulus (M_R) of ATBs has been studied in laboratory evaluations, field investigations, and empirical and mechanistic modeling. However, most ATBs' M_R values available in the database of the Alaska flexible pavement design software were obtained from in-service roadways through nondestructive testing and back calculation. Therefore, there was a need to characterize these stabilized materials by taking into account the main factors that influence their engineering behavior. In this study, the M_R characterization of two types of ATBs was achieved through laboratory testing: hot asphalt-treated base (HATB) and foamed asphalt-treated base (FATB). The effects of loading amplitude, confining pressure, temperature, binder content, and aggregate source and properties on the resilient behaviors of HATB and FATB were investigated. Testing results were discussed and used to develop stress-dependent M_R equations for both HATB and FATB that can be incorporated in current pavement design procedures. The effects of temperature and material variables were correlated to regression constants of the equations.