Effect of Laboratory Aging Levels on Asphalt Binder Chemical/Rheological Properties and Fracture Resistance of Asphalt Mixtures

This study aimed to evaluate the effect of laboratory aging levels on chemical and rheological properties of asphalt binder as well as fracture performance of asphalt mixture. Compacted asphalt mixtures were laboratory aged at 85°C for 0, 2, 5, 7, and 10 days and then subjected to the semicircular bending (SCB) test. Asphalt binders were extracted from the aged samples for further chemical and rheological characterization. Chemical characterization included Fourier transform spectroscopy (FTIR) and gel permeation chromatography (GPC). Rheological tests included bending beam rheometer (BBR) and linear amplitude sweep (LAS) tests. Asphalt binder rheological characterization showed that the cracking resistance of asphalt binders decreased with an increase of aging level. Statistical analysis of SCB test results indicated that there is no significant drop in the critical strain energy release rate, Jc, between 2- and 5-day aging, but 10-day aging resulted in a significant decrease in Jc. It was observed that the aging susceptibility of asphalt mixtures in terms of SCB results was consistent with FTIR and LAS test results.