Assessment of Surface Free Energy Characteristics of Performance Graded Asphalt Binders

摘要: Moisture-induced damage of asphalt mixtures can contribute to serious distress, reduced performance and increased maintenance pavements. A recent study by the Texas Transportation Institute (Cheng et al., 2002) shows that surface free energies (SFE) a HMA mix its constituents (aggregate binder) be valuable indicator moisture in because they relate some mechanisms are not addressed retained strength tests currently used many transportation departments . To this end, SFE selected graded binders was evaluated from measurement dynamic contact angle between an binder liquid solvent. Dynamic Wilhelmy Plate Method (DWPM) for measurements with modifications including using cylindrical or tube samples instead plate samples. Two different binders, namely PG 64-22 70-28, were used. Results show 70-28 has higher energy cohesion, which provides cohesive than 64-22. Thus, is expected provide better resistance moisture-induced damage. Research being pursued evaluate effect anti-strip additives on binders. The findings suggest concept develop new test methods identifying susceptible mixes during design s tage.