Improving storage stability and rheological performance of asphalt rubber modified with nanosilica and Sasobit

In this study, nanosilica (NS) and Sasobit were incorporated into asphalt rubber (AR) binder to produce Si/Sa-AR binder. Various conventional rheological tests were performed to determine the rheological properties of Si/Sa-AR binder. Microscopic tests and four components test were performed to investigate the interaction mechanism of Sasobit and NS with the AR binder. The results show that the combination of AR binder with Sasobit and NS improves the resistance of asphalt to fatigue cracking and permanent deformation. Microscopic images of the AR binder show a 'dendritic' structure consisting of multiple swollen crumb rubber (CR) particles and a three-dimensional (3D) network structure, which is reflected in the excellent rheological properties of AR. The addition of Sasobit and NS breaks up the 'dendritic' structure while improving the 3D network structure. NS promotes the formation of a homogeneous multiphase system of the modified asphalt binder, which in turn improves the storage stability.