Electron Paramagnetic Resonance on Asphaltic Materials
Abstract
Asphalts have been used as paving materials for many years and a great deal of research has been conducted in the physical properties needed for good for good performance. In the past, some chemical research has been performed on these materials as well. Questions have remained as to what chemical properties are important in the design of a long-lasting pavement structure. This study has used a spectroscopic technique to investigate the aging and catalytic properties of asphalts. Electron Paramagnetic Resonance (EPR) was used to identify the role of free-radical species in these processes. Two paramagnetic categories were identified: organic free radicals and vanadium transition metal ions. Free radical and transition metals are highly reactive, and may play important roles in the oxidation process that contributes to aging. The results of this study indicate that there may be a relationship between the concentrations of the free radical species to the aging index and to the changes in the specific clay gel fractions. Keywords: Asphalt; spectroscopic technique; vanadium ions; transition metal.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1987
- Accession Number
- ADA178471
Entities
People
- Betty J. Humphrey