Investigating the Addition of Organomontmorillonite Nanoclay and Its Effects on the Performance of Asphalt Binder

Abstract

Asphalt binder aging is a complex phenomenon that plays an essential role in reducing flexible pavement serviceability. The aging resistance of asphalt binder can be enhanced through the binder modification. This research investigates the impact of aging on unmodified and organo-montmorillonite (OMMT) nanoclay modified asphalt binders. In this study, laboratory aging is carried out for asphalt binders modified with two types of OMMT nanoclays at different dosages (2% and 4% by weight of the binder). The asphalt binders are subjected to short-term and long-term aging using a rolling thin-film oven and pressure aging vessel equipment. Rheological properties of the aged and unaged binders are determined using a dynamic shear rheometer. In addition, storage stability, full performance grading, and rutting resistance of the binders are evaluated and compared. Aging indices were calculated to investigate the aging behavior of the unmodified and modified binders. The results showed that the montmorillonite nanoclay-modified asphalts had improved resistance to aging compared with the unmodified binder.