Improvement of Rheological Properties of Asphalt Binder by Adding Composite Montmorillonite Nanoclay

Abstract

Various concentration of composite nanoclay was studied to determine the physical and rheological properties of three types of asphalt binders. One type of composite Nanoclay in different concentrations (0%, 3%, 5%, and 7%) by weight of bitumen were used and blended with three asphalt binder types (80/100-60/70 and PG-76|) penetration grade. The physical properties of unaged base and nanoclay modified asphalt were characterized using viscosity, softening point, and penetration tests. Dynamic Shear Rheometer were used to determine the rheological properties of unmodified and nanoclay modified asphalt in accordance with AASHTO T315 in order to evaluate the effectiveness of composite nanoclay type and concentration on the physical and rheological properties of asphalt binder. The results indicated remarkable increment in softening point; viscosity and decrement in asphalt binder’s penetration for both types and contents of organic nanoclay and asphalt types as compared with unmodified bitumen. The results of the experiments indicated that the addition of nano particles was helpful in increasing the complex modulus values and in improving rutting resistance of the RTFO binder. The phase angle of the binders generally decreased with an increase in nano content and RTFO aging procedure. Also, the results indicated that modified binders show better rheological properties compared to standard bitumen for all asphalt type. The addition of Nanoclay to base asphalt binder has led to noticeable improvements in aging resistance this may be due to the homogeneous dispersion of nano particles consisting of layer silicate in the asphalt medium. The main objective of this study is to study the effect of nanoclay on the physical and rheological properties for three different type of binder.