Utilization of Distilled Water to Observe Surface Contact Angle of Polymer-Modified Bitumen

Stable sub-grade and reliable structural layers are required in road pavements to ensure long serviceability.One of the road distresses associated with the sub-grade (unbound soil) or top (bituminous) structural layer failure is rutting in flexible pavement.This is the reason why better rutting resistance is highly desirable in bitumen to prevent potential damage as well as to ensure higher durability for the pavement.Studies on surface material identified the concept of contact angle by testing liquids on solid surface.This concept can also be applied to bitumen to determine its ability to repel or attract a particular liquid such as water in line with the modification rate.Therefore, this study was conducted in an effort to improve rutting and fatigue through low-density polyethylene (LDPE) polymer-based modified bitumen.The focus was to determine the ability of measuring water contact angle (WCA) to differentiate several types of modified bitumen.Polymer-modified bitumen was produced through high shear mixing using virgin and recycled LDPE to improve its rutting resistance.Moreover, standard tests such as ring and ball softening points were conducted to determine the penetration number and softening point to confirm the modification results.WCA tests were applied to both the unmodified and the modified bitumen, and some differences were observed in the results.