Predictive quantitative model for assessing the asphalt-aggregate adhesion quality based on aggregate chemistry

Abstract

Asphalt-aggregate adhesion quality is a key factor in the mechanical performance of asphalt pavements. This work presents a predictive model of moisture damage in asphalt-aggregate systems based on aggregate chemistry. The study included seven siliceous aggregates and two calcareous aggregates, and one source of asphalt binder.  Specimens composed of an aggregate core, a 20 μm thick asphalt film and a metallic stub were tested via a pull-off debonding experimental setup after multiple water conditioning processes. The experimental results i.e. maximum load at failure, F_max, work of fracture, W_f, and adhesive failure area at the surface of the aggregate, A_% show that for siliceous aggregates, the SiO₂ content increases moisture susceptibility while the opposite is seen for Fe₂O₃ and CaO, and that for calcareous aggregates, moisture susceptibility increases with their SiO₂ content. These results were used to propose, for the first time, an empirical moisture damage predictive model for siliceous aggregates based on aggregate chemistry.

KEYWORDS:

• Asphalt pavements
• mineralogy
• asphalt-aggregate system
• adhesion
• moisture damage

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was made possible due to the Inter-school (Civil engineering – Geosciences) research grant provided by the Office of the Vice-presidency of Research of Universidad de los Andes.