Effects of crystalline wax and asphaltene on thermoreversible aging of asphalt binder

Abstract

ABSTRACT Thermoreversible aging is an important factor that affects the durability of asphalt pavement in cold and high altitude areas. Although there has been increasing attention to the significance of thermoreversible aging in recent years, the contribution of asphalt components to thermoreversible aging remains unclear in the existing literature. To this end, potential components that may affect the thermoreversible aging of asphalt binders were regarded as additives in this study. The extended bending beam rheological test (ExBBR), thermal stress calculation, and modulated differential scanning calorimetry (MDSC) analysis were employed to study the effects of two kinds of crystalline waxes with different carbon atoms and one asphaltene type as additives on the thermoreversible aging properties of asphalt binder. The findings showed that under conventional 1-hr conditioning cold storage, adding 1% or 3% C20H42 significantly improved the low-temperature rheological properties and reduced base asphalt's thermal stresses. However, no significant effect of the C20H42 additive on thermal stress reduction was observed when considering the asphalt binder's thermoreversible aging. Both low-temperature rheological tests and thermal analysis confirmed that C20H42 significantly increased thermoreversible aging in the base binder; however, C32H66 and asphaltene additives did not produce a similar effect.