Influence of Same-Grade Asphalt Binder from Different Sources and Aging on Moisture Damage Characteristics of Asphalt–Aggregate System

Abstract

India is witnessing unprecedented growth in its road network. To meet the asphalt binder demand, distillation towers have been loaded with crude oil from different sources. Although the quality system is expected to guarantee reduced variability, a quality system based on traditional indexes may lead to high variability in binders of the same grade. Because India relies on traditional indexes for quality control, we aimed to quantify such variability and its impact specifically on moisture damage resistivity. Additionally, the response of binders from different sources in the short term and long term has also been evaluated. Five binder sources were selected, and they were meant to conform to the same viscosity grade. Thereafter, moisture damage assessment tests such as surface free energy (SFE) measurements, bitumen bond strength (BBS) test, rolling bottle test (RBT), and boiling water test (BWT) were performed in unaged, short-term aged, and long-term aged conditions. Additionally, variations in chemistry of the binders were assessed based on Fourier transform infrared (FTIR) spectroscopy. It was concluded that the chemical and moisture damage characteristics had a strong dependence on the source of the binder. Furthermore, there was substantial variability in the moisture damage performance for binders from different sources. This implied that quality systems based on traditional indexes may not be stringent enough to reduce the variability. The impact of aging on the moisture damage resistivity of the asphalt–aggregate system was also discussed. Given the limited information available in the literature on asphalt binder variability of the traditional grading system, the data reported in this study can serve as reference for future studies dealing with its characterization and assist in developing a strategy for reducing uncertainty related to the performance of asphalt mixes.