Obtaining of modified bitumen with optimum quality through mixing of natural bitumen (gilsonite), bitumen and thinner oil

Abstract

In this research the modified bitumen was obtained from natural bitumen (gilsonite), B160/220 and B50/70 bitumen and thinner oil in different adding amount by weight. Some engineering properties of these materials were investigated and testing results were compared with each other and standards. It was found that standard penetration was reduced, viscosity and complex modulus were increased and there was no noticeable change on softening point and on phase angle by the addition of natural bitumen. The test results on the Marshall specimens showed that retained Marshall stability, indirect tensile strength ratio, stiffness modulus at temperatures of 15, 25 and 35 °C and fatigue life were significantly increased by the addition of natural bitumen (gilsonite) to normal bitumen. Furthermore, Şırnak (Silopi) asphaltites of 2, 4 and 8 % by weight in ratio were added into B160/220 bitumen. The mechanical properties of original bitumen and modified bitumen additives with additive asphaltite were studied and the optimum content of 4 % asphaltite and good results were found.