Volume 2, Issue 8 (September 2005)
Obtaining Creep Compliance Parameters Accurately from Static or Cyclic Creep Tests
Obtaining creep compliance parameters that accurately represent the creep response of asphalt mixtures is critical for proper evaluation of the thermal cracking performance, as well as load induced cracking performance of asphalt pavements. A power law, which uses three parameters to describe the creep compliance curve, is commonly used for asphalt mixtures. However, the specific values of the parameters obtained can depend on both the testing and the data interpretation methods used. Different testing methods (for example, static versus cyclic creep) offer different advantages and disadvantages related to complexity in testing, as well as in the sensitivity of the data obtained from each test to the compliance parameters of interest. In general, cyclic creep tests provide greater sensitivity and accuracy at shorter loading times, while static creep tests are more accurate and reliable for the determination of the long-term creep response.