Assessing the surface free energy of modified asphalt binder with image processing technique

When the asphalt binder does not comply with the required specification for pavement, the suggested remedy is the implication of modifiers to enhance the quality. In the present investigation, asphalt cement binder was modified with varying percentages of two types of modifiers, Sulfur (3, 5, 7, and 10) % and Carbon Black (5, 10, and 15) % by weight of asphalt cement. The image processing technique was implemented to evaluate the surface free energy components (dynamic and static contact angles) of the treated asphalt cement by implementing the sessile drop and Wilhelmy plate techniques. The aim of this investigation is to assess how the image processing can detect the variation in the adhesive properties through the assessment of surface free energy of the asphalt cement due to the addition of the modifiers. For the comparison process, the surface free energy components of the control asphalt are also determined. Considering the test result obtained, it was concluded that Carbon black is more appropriate additive, it gives an ultimate total surface free energy increment of (7.7 and 6) % as compared with (2.8 and 3.1) % for sulfur when Sessile drop and Wilhelmy plate methods are implemented respectively when compared with the control binder.