Evaluation of the Dynamic Complex Modulus Test and Indirect Diametral Test for Implementing the AASHTO 2002 Design Guide for Pavement Structures in Florida

The primary objective of this study was to evaluate the dynamic complex modulus test and indirect tensile test for implementing the American Association of State Highway and Transportation Officials (AASHTO) Mechanistic-Empirical (M-E) Design Guide for Pavement Structures in Florida. The specific goals of the study were to develop the dynamic testing capabilities, to perform the dynamic complex modulus test and indirect diametral test, and to establish a database for referencing available resilient modulus and dynamic modulus values for targeted Florida asphalt concrete mixtures. To achieve the objectives and goals, a complete dynamic testing system was purchased to perform the temperature controlled dynamic tests. A laboratory experimental program was also developed to evaluate 20 selected Superpave asphalt concrete mixtures with a range of aggregates and mix designs. One type of asphalt binder, PG 67-22 (AC-30), was used for all mixtures tested. The 20 asphalt concrete mixtures were tested for both dynamic complex modulus and indirect tensile resilient modulus. The master curves were developed and constructed using the time temperature superposition principle. The Witczak prediction model was adopted to perform the comparison between predicted and measured dynamic modulus for all mixture series. The comparison indicated that the Witczak prediction model worked very well for the Florida asphalt concrete mixtures tested in this study. A comparative study was also made between the dynamic modulus and resilient modulus test results. The linear regression analysis indicated that the total resilient modulus increased with an increase in dynamic modulus at a specific loading frequency. The resilient modulus values were comparable with the dynamic modulus values at the loading frequency of 4 Hz.