Abstract
Mechanistic–empirical pavement design (using AASHTOWare Pavement ME Design software) incorporates inputs at three different levels (i.e., Level 1, Level 2, and Level 3). Level 1 input is preferred over Level 2 and Level 3 in AASHTOWare Pavement ME Design software. Level 1 inputs are project- or job-specific, and are obtained through direct measurements or laboratory testing. Level 1 input measurements, such as the resilient modulus ( M R ), might require additional resources to those required for Level 2 inputs. Many transportation agencies develop Level 2 inputs, which are more region-specific. For unbound materials, M R is considered one of the fundamental material properties. Measuring M R through laboratory testing requires advanced equipment and trained technicians, and the test is time-consuming. This study is an evaluation of the correlations between the resilient modulus of commonly used unbound materials in Idaho and the California bearing ratio (CBR) to develop Level 2 inputs. In addition, the recently introduced light weight deflectometer (LWD) modulus was correlated with the resilient modulus. The results of this study demonstrate a good and promising correlation between resilient modulus and LWD modulus, and a fair correlation between resilient modulus and CBR.