Analysis of Rheological Properties and Moisture Resistance of Nanoclay-Modified Asphalt Binders

Abstract

The primary aim of this study is to improve the rheological properties and moisture resistance of asphalt binder by the modification of a sustainable material named “nanoclay.” Rheological properties and moisture resistance of selected nanoclay-modified asphalt binders have been evaluated. Three types of nanoclays (Cloisite 10A, Cloisite 11B, and Cloisite 15A) at 1, 2, and 3% by the weight of asphalt binder were blended with a base binder (PG 64-22) from two sources. A blending protocol consisting of a duration of 2 h, a rotation of 2000 rpm, and a temperature of 1500 C were used to blend the nanoclays with the asphalt binders. Rheological properties of nanoclay-modified asphalt binders were then determined by using a Rotational Viscometer (RV) and a Dynamic Shear Rheometer (DSR). The viscosity of the nanoclay 2% Cloisite 10A-modified binder was about 248% of that of the neat binder. It was found that the consistency of a nanoclay-modified binder was significantly higher than the neat binder. The rutting factor (G*/sinδ) also increased significantly for the nanoclay-modified asphalt binders. An Optical Contact Analyzer (OCA) was used to evaluate moisture susceptibility. Binder modified by 3% Cloisite 10A showed the highest surface free energy and cohesiveness. An Atomic Force Microscope (AFM) was used to characterize the nanoclay-modified samples. Surface roughness increased, but no improvement was observed in the DMT (Derjaguin–Muller–Toporov) moduli values. Besides, the adhesion parameter, which indicates the moisture susceptibility, increased significantly.