AN IN-DEPTH EVALUATION OF MOISTURE SENSITIVITY OF ASPHALT MIXTURES

The main objective of this research was to evaluate current test methods employed to determine moisture sensitivity as well as provide research into new methods for measuring moisture susceptibility. Currently AASHTO T-283 is used almost exclusively to determine moisture susceptibility of an asphalt mix. However, within the AASHTO T-283 procedure a range of values are allowed for important test variables. Specifically the variables are sample air voids and degree of saturation prior to conditioning. It is important to understand the effect of these variables on test results. An alternate to measuring indirect tensile strength is a test that evaluates a mixture's fundamental material properties. An objective of this research was to provide a method for evaluating a mixture's moisture sensitivity that is simple to perform and provides information on the mixture's cohesion and friction angle. A relatively simple test is proposed that measures cohesion and friction angle for asphalt mixtures. In addition, it is desired to incorporate the Strategic Highway Research Program (SHRP) Shear Tester (SST) as a tool in moisture sensitivity evaluation. A standard mix analysis test was performed to determine if it was capable of detecting moisture susceptible mixtures.