Anti-aging additives: proposed evaluation process based on literature review

Asphalt binder ageing alters its chemical and physical properties in a manner to make it brittle and more susceptible to thermal and fatigue cracking. The ageing rate of asphalt binders depends on a combination of different factors related to their chemical composition, environmental conditions and mix design. In order to prevent ageing, anti-ageing additives are used. The selection of the optimal additive should follow an iterative process. The additive choice is made concerning each case studied. Then, the selected modified asphalt binder is short-term aged by RTFOT and long-term aged by PAV and ultraviolet (UV) weathering. Rheology performance parameters are measured by DSR and BBR before and after ageing. Consequently, ageing indices are calculated to evaluate the appropriateness of the additive. The paper discusses several findings on the rheological level accordingly to the literature. Finally, a process is proposed to harmonise the research and the engineering practices in studying anti-ageing additives effects on asphalt binders.

Automated summary

Asphalt binder ageing makes it brittle and prone to cracking, with the rate depending on factors like chemical composition and mix design. Anti-ageing additives are used to prevent ageing, with the selection process involving iterative steps. Evaluation of the additives' appropriateness can be done through rheology performance parameters before and after ageing.