New Parameter to Evaluate Moisture Damage of Asphalt-Aggregate Bond in Using Dynamic Shear Rheometer

Abstract

Most of the techniques used today to evaluate practically moisture damage in asphalt pavements are involved in compacted asphalt mixtures. These tests generally simulate field conditions, and provide a performance-related parameter of moisture effects by applying mechanical techniques. No test of the compacted mixtures, however, can isolate the fundamental and rheological properties of the asphalt-aggregate bond, which hinder proper understanding and quantification of the moisture damage phenomenon. To avoid these complications and improve the evaluation of asphalt-aggregate interfacial properties in moist situations, this study proposes a new experimental method. In this method, dynamic shear rheometer was used to measure asphalt-aggregate interfacial properties. A degree of moisture damage relating to the interfacial properties was then quantified using linear viscoelastic concepts to propose a meaningful parameter, called wet to dry yield shear stress ratio. Moreover, possible factors such as film thicknesses, conditioning times, and chemical effects were studied in terms of the W/D YSS ratio.