Rheological properties investigation of bitumen modified with nanosilica and polyethylene polymer

Abstract

Performance of bituminous binders in terms of rutting and fatique is known to be related with rheological characteristics of asphalt binders. To enhance the rheological properties of binder, a modification using composite polymer and inorganic nanosilica becomes recognized as it highly improves the flow and deformation of the modified binders. This study investigates the application of polyethylene polymer and inorganic nanosilica for enhancing rheological properties as well as the oxidative aging resistance of asphalt binders. Conventional and Superpave binder test techniques. Using dynamic shear rheometer (DSR) was used to investigate the performance and rheological behaviors of the nanocomposite-modified binders. Changes in chemical bonding and morphological properties due to nanosilica were also investigated using Fourier transform infrared spectroscopy (FT-IR) and field emission scanning electron microscopy (FE-SEM). Nanosilica was added into polymer modified bitumen at different percentages (1% to 6%) by weight of bitumen binder. Results of the investigations show that composite nanosilica/polyethylene modified binders will not undergo phase separation during storage due to improved viscoelastic properties. The Superpave rutting parameter shows that nanosilica modified binders have higher resistance to permanent deformation both before and after rolling thin film oven (RTFOT) aging. FE-SEM and FT-IR investigation shows that nanosilica modified binders are less susceptible to oxidative aging hardening