Effect of Warm Mix Additives on the Properties of Unmodified and Polymer Modified Asphalt Binders

This paper discusses the effect of warm-mix asphalt (WMA) on the morphological, chemical, and physical characterization of asphalt binders. The experimental plan includes two base asphalt binders (unmodified and polymer-modified) and four different WMA additives (i.e., sasobit, sasobit redux, rediset, and cecabase) at varying dosages. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and various empirical and fundamental tests were conducted for the characterization. SEM and FTIR confirmed the suitability of the adopted blending technique for uniform/homogeneous blend with pure physical interaction between WMA and asphalt binders. The physical form of WMA additives was observed as a crucial attribute affecting the morphology/dispersion within asphalt binders. In addition, all the WMA binders displayed similar to better physical characteristics than the base asphalt binders. Notably, the type of base asphalt binder was depicted to play a vital role in manipulating the characteristics of the WMA binders. Considering the distinct nature and dosage of WMA additives chosen in this study, it is suggested that different WMA binders be produced at the same or optimum dosage level to compare different physical and chemical properties effectively.