Evaluation of field aging effects on asphalt binder properties

The oxidative aging that takes place in the asphalt binders used in the construction of asphalt pavements significantly affects the performance of the pavements during their service life. In this paper two issues that still generate a lot of debate in the research community are investigated: how far aging penetrates inside the asphalt layer and how reasonable laboratory aging tests simulate the aging occurring in the field. Cores were obtained from three cells at MnROAD facility and the binders were extracted and recovered from 25 mm slices cut along the depth of the cores. The properties of the recovered binders as well as the properties of the original binders aged in laboratory conditions were investigated, using standard testing procedures part of the current specifications as well as additional test methods. The results indicated differences in aging effects with location inside the asphalt layer and significant differences between the recovered and the laboratory aged binders.