Storage Stability of Bituminous Binders Reinforced with Nano-Additives

The experimental investigation presented in this paper focused on storage stability of bituminous binders containing nano-sized additives. Several blends were prepared in the laboratory by combining three base bitumens with two different types of nanoclays and one type of carbon nanotubes at various dosages. A technique based on the combination of simple shear mixing and sonication was proposed to achieve adequate dispersion of nano-particles in bitumen. Capability of materials to withstand segregation phenomena was evaluated by means of viscosity measurements performed on samples derived from simulative laboratory storage tests. Results obtained in the study revealed that high-temperature stability of nano-reinforced binders is dependent upon physico-chemical properties of base components, thus highlighting the key role played in such a context by interaction mechanisms that take place between nano-additives and dispersing bituminous medium.