Master of Science in Civil Engineering (MSCE)
Civil and Environmental Engineering
The dynamic modulus test is conducted based on the assumption that no damage is induced during the testing process and that measurements are conducted within the linear viscoelastic region. In addition, significant damage is expected to occur during the flow number test process. While these assumptions are well-defined, the levels of damage taking place during these tests have not been quantified. The objectives of this study were to quantify the levels of damage in the dynamic complex modulus and flow number tests using x-ray computed tomography (CT) and to characterize the microstructural properties of asphalt mixtures under loading. Four Superpave mixtures including one conventional hot-mix asphalt (HMA) and three warm-mix asphalt (WMA) mixes were evaluated in this study. Two WMA processes (i.e., water foaming and RedisetTM additive) were used in the preparation of the WMA mixes. In addition, reclaimed asphalt pavement (RAP) was used in the preparation of the mixes at a content ranging from 15 to 30%. Results of the experimental program indicated that the damage taking place in the dynamic modulus test is minimal and homogeneous while the damage taking place in the flow number test is significant and heterogeneous. In addition, specimen preparation may significantly influence the three-dimensional air voids distribution in HMA.
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Ying, Hao, "Using X-Ray Computed Tomography to Quantify Damage of Hot-Mix Asphalt in the Dynamic Complex Modulus and Flow Number Tests" (2011). LSU Master's Theses. 675.