Influence Of Nano Material Additive On Surface Free Energy (Sfe) Of Asphalt Binder

One of the essential properties of asphalt binder is the resistance to moisture damage. Therefore, implementation of nano material additive can control and improve the resistance to moisture damage of the asphalt pavement, change the temperature susceptibility characteristics, and create a new material with different physical and rheological properties. In this investigation, one type of Nano material (silica fume) was mixed in different percentages with (40-50) penetration grade asphalt cement binder. The resulted modified asphalt cement was subjected to static contact angle measurements and determination of surface free energy components of the binder using three types of probe liquids and Sessile drop technique and with the aid of equations of work of adhesion. A digital camera has been implemented to capture the image of the drop of liquid formed over the surface of a glass slide coated with asphalt cement. The captured images were transferred to the image processing software (Comef. 4.7) to determine the static contact angle. It was observed that these contact angles vary according to the type of probe liquid, and percentage of Nano materials added to asphalt cement. It was concluded that adding one and two percent of Nano material to asphalt cement has implies an increment in the surface free energy of the binder by 28.8 % and 18.4 % respectively, while the implementation of three and four percent of silica fume into the binder exhibit a reduction in surface free energy by 21.3 % and 24.2 % respectively. However, the change in contact angle was fluctuating and not significant.