Abstract
With the recent interest on the design and use of rubber modified materials in paving projects there is an immediate need for evaluating the moisture susceptibility of these mixtures. In this study a long term immersion test was considered for evaluating the moisture susceptibility of asphalt rubber mixtures and compare them to conventional mixtures. Two sets of conditioning were considered. The first one, hot immersion conditions at 60 degrees C, while the second at 25 degrees C representing the average pavement in-service temperature. The mixtures included in this study represent materials used in actual paving project. Samples from several immersion times were considered, and up to 14 days of immersion. The moisture susceptibility of the rubber modified materials was then compared to that of conventional paving mixtures. For such analysis, first, the optimum binder content of the modified and the conventional mixtures was evaluated. Then, three comparative experiments were conducted, and including mixtures prepared at the optimum binder level, at the same air void content, and at the same binder content. In addition to the stability and now evaluation of the mixtures at different immersion times, stiffness analysis were conducted.