Review on laboratory preparation processes of polymer modified asphalt binder

Several previous studies have documented the progress in polymer modified asphalt binder with respect to materials’ types and properties. However, limited or no effort was made to document findings on the laboratory preparation practices of polymer modified asphalt binder. Full and clear disclosure of asphalt blend preparation method is necessary for research continuity, reproducibility, and accurate adaptation by future studies for analogy and reliable conclusions. The laboratory preparation processes of various modified asphalt binders have been reviewed in this study. Factors affecting the optimal mixing of asphalt-polymer blends were summarized. The optimal mixing conditions associated with different asphalt modifiers were documented. Gap in the literature on the current practice for the preparation and reporting of various modified asphalt binder was discussed. Modifiers include styrene butadiene styrene (SBS), polyethylene (PE), waste tire rubber or crumb rubber (CR), ethylene vinyl acetate (EVA), sulfur, polyphosphoric acid (PPA), epoxy, polyurethane, nano-materials, etc. Currently, there is lack of modern innovative approached in the preparation of modified asphalt towards better performance. There is no clear standardized definition of term associated with asphalt binder preparation process. Given the limited and common types of polymers utilized for the modification of asphalt binder, it is possible to standardize the mixing procedure for several polymers. Doing so could ease research continuity and facilitates accurate comparison of new studies with earlier ones.