Standard Ruggedness Study on Moisture Induced Sensitivity Tester

Abstract

Moisture damage is one of the major issues causing premature failure of Hot Mix Asphalt (HMA) pavements. However, there are no reliable test methods to determine moisture sensitivity in the laboratory. Moisture Induced Sensitivity Tester (MIST) is a new procedure that replicates moisture conditioning in the laboratory. However, the MIST does not have a standard test method and current testing is performed based on the manufacturer recommended settings. A ruggedness study (ASTM E1169) was performed on the MIST to determine if the tolerances of the test parameters have any impact on test results. The study was performed on only one mix. The manufacturer suggested test conditions are pressure, temperature, air void content (VTM) and height of compacted sample. The effect of the tolerances of these test conditions on indirect tensile strength (ITS) and Volume Change of the MIST conditioned samples were analyzed. The results from this study show that the tolerances on VTM and height of the sample had an effect on ITS of the HMA compacted samples while the VTM alone had an impact on Volume Change. A small experiment was performed to determine if the tolerance of the water bath soak after MIST conditioning had an impact on ITS values of the compacted HMA samples. The results suggest that the recommended 2-3 hour water bath soak had an effect on ITS values.