Influence of Long-Term Laboratory Aging on Properties of Binder

Aging of the binder is an important factor that affects the service life of flexible pavements. The main objective of the study is to evaluate the effect of long-term laboratory aging on binder. Normal oven aging in the laboratory at 85 °C for a varying period of 5, 6, 7, and 8 days was used to simulate the long-term field aging. Rheological characteristics of fresh VG-30 binder and laboratory aged binders were evaluated using a rheometer. Frequency sweep test and temperature sweep tests were conducted. Fourier Transforms Infrared Spectroscopy (FTIR) was employed to evaluate the effect of aging on the chemical composition of the binder. Scanning Electron Microscopy (SEM) was used to analyze the change in morphological characteristics of the binder with aging. The study demonstrated that the aging results in the reduction of fatigue cracking resistance of binders at low temperatures. Rutting resistance of binders increased with an increase in aging. FTIR results indicated that there is no significant change in the functional groups, the only difference was in the intensity of their peaks. Morphological changes in aged binders were well identified from SEM images.