Evaluation of rutting, fatigue and moisture damage performance of nanoclay modified asphalt binder

• Nanoclay (CL-30B) addition to binder showed improved rutting resistivity potential.
• SFE approach showed improved moisture resistivity of binder with CL-30B addition.
• LAS study showed improvement in fatigue life of binder with CL-30B modification.

Recent impetus on utilization of different types of nanomaterials for modification of asphalt binders has motivated the authors to undertake the present study. The present study evaluated the rutting, fatigue and moisture damage performance of nanoclay (CL-30B) modified asphalt binder based on newly adopted test methods. Based on Superpave rutting parameter, it was observed that rutting resistivity of a binder increases with an increase in CL-30B content. Moisture resistivity of CL-30B modified asphalt binder with different types of aggregates system was studied using Surface Free Energy (SFE) approach. The SFE components of nanoclay modified binder were measured using Wilhelmy plate method. Four different types of aggregates (Basalt, Limestone, Sandstone and Granite) were chosen for the study. Overall increase in total SFE of the binder was observed with addition of CL-30B. Increase in work of cohesion and decrease in work of debonding was observed with an increase in CL-30B for all type of considered aggregate. Based on Energy ratio (ER), asphalt binder with basaltic aggregate was found to have better moisture damage resistivity among different types of aggregate selected in this study. The fatigue performance of CL-30B modified binder was evaluated using Linear Amplitude Sweep (LAS) test which is based on Visco Elastic Continuum Damage (VECD) theory. The analyses of the data showed that addition of CL-30B enhances fatigue life of a binder. The study showed potential of CL-30B to enhance various rheological performance of a binder for better and long lasting pavements.