Experimental study on the effects of modification with nanoclay on the properties of an SMA mixture

Abstract

The modification of bitumens with NM has shown results in the improvement of binder properties, in particular thermal susceptibility. This article aims to present a study to demonstrate the effects of modifying a bituminous mixture (BM) of the Stone Mastic Asphalt (SMA) type with nanoclay. The nanoclay used was of the hydrophilic bentonite type. The modification of the bitumen was carried out by introducing and dispersing in conventional bitumen a 35/50 amount of nanoclay corresponding to 4% of the weight of the modified binder. The bitumens, conventional and nanomodified, were characterized by determining penetration, ring and ball softening temperature and viscosity. In the subsequent BM, to investigate the influence of the nanomodification, tests of permanent deformation (PD), modulus of deformability, resistance to fatigue and sensitivity to water were carried out. The results obtained showed that the nanomodified SMA mixture showed better resistance to fatigue, increase in indirect tensile strength (ITS), less sensitivity to and better resistance to PD.