Evolution of the Viscoelastic Transition with In-Field Aging of Bituminous Surfacing Treatments

• Published in: Journal of testing and evaluation 2023-07, Vol.51 (4), p.2057-2074
• Main Authors: Goosen, Elaine Simone, Jenkins, Kim Jonathan
• Format: Article
• Language: English
• ISSN: 0090-3973; 1945-7553
• DOI: 10.1520/JTE20220271

The beneficial properties of bitumen deteriorate with oxidation-induced age-hardening. At intermediate temperatures or stiffness values, hardening may lead to fatigue failure. Current binder selection processes for bituminous surfacing treatments depend on penetration and softening point values and the degree of aging these properties experience in the intended environment. In the context of transitioning engineering knowledge to performance grades, there is a need for research to determine which fundamental properties may help select an appropriate binder for specific traffic and climatic conditions. The study extracted and recovered binders from bituminous surfacing treatments between the ages of 1 and 22 years. These binders were subjected to frequency sweeps and creep tests with the dynamic shear and bending beam rheometers, respectively. Various durability indicators are calculated from the raw data and master curves. The evolution of these parameters is analyzed for increased surfacing age and environmental exposure. The results of the viscoelastic transition temperature (Tvet) and modulus (Gvet), and crossover frequency (ωc) are presented and indicate correlations with surfacing age when grouped by surfacing type and environmental conditions.