Moisture Susceptibility of Aggregate and Asphalt Binders

Moisture susceptibility has long been acknowledged as a significant factor contributing to the degradation of pavements over an extended period. This type of damage can arise due to various factors, including non-compliance of aggregate binder systems. The primary objective of this proposed research is to quantitatively assess the interaction between binder and aggregate at the interface level, specifically in terms of adhesion forces at the molecular level between bitumen samples and various types of aggregates. In this investigation, three Performance Grade (PG) binders approved by the Arkansas Department of Transportation (ARDOT), originating from two distinct suppliers were investigated in the laboratory. Additionally, some of these binders modified with a selected anti-stripping agent were evaluated to determine their resistance to moisture damage.  Subsequently, the researchers conducted aging simulations on the binders and performed macro-level testing using several techniques, including Rotational Viscosity (RV), Dynamic Shear Rheometer (DSR), and Pneumatic Adhesion Tensile Testing Instrument (PATTI) test. In addition, a moisture damage-related test called the Texas Boiling Test was conducted. The percentage coating was determined using an internally created automated tool, ensuring the elimination of any subjective factors. The results of this research are anticipated to assist the transportation agencies and asphalt producers in assessing the efficacy of the usage of the PATTI in evaluating moisture resistance of asphalt binder and aggregate systems.