Physico-Mechanical and Morphological Properties of Wax Latex-Modified Asphalt Binder

Asphalt binders are modified to address various types of distresses, especially crack-related and permanent deformation of the pavement structure. This study focuses on evaluating the effects of Gripper, a new wax additive, on the performance of natural rubber latex (NRL)-modified asphalt binders. The morphology of the modified asphalt binders was also investigated. In this study, two percentages of NRL were considered, i.e., 3% and 6% based on the weight of the asphalt binder. Penetration value, softening point, rotational viscosity, storage stability, complex modulus, phase angle, rutting potential and torsional recovery parameters were determined to analyze the base asphalt binder (60/70) and NRL-modified asphalt binders (with and without Gripper). Also, the dispersion efficiency of NRL in the asphalt binder was observed using a polarizing optical microscope. The results demonstrate that the addition of NRL improved the performance of the asphalt binder in terms of rutting and fatigue resistance. The addition of Gripper has further improved the stability and mechanical performance of modified asphalt binders. An agglomerated and globular continuous network of mixed microstructures was formed in the modified asphalt binder irrespective of aging condition. Moreover, the unaged, short-term aged and long-term aged binders prepared with the incorporation of Gripper indicate uniformly dispersed network morphology. It can therefore be concluded that the modified asphalt binders prepared with the newly introduced additive portrays better resistance toward rutting and fatigue failures.