Short-Term Aging Behavior of Bitumen Commonly Used in Bangladesh for Road Construction

The engineering performance of bituminous pavement highly depends on the aging processes of bitumen. A developing nation like Bangladesh mostly depends on imported bitumen along with locally refined limited sources. Engineers often face significant challenges and concerns when early cracks develop in the field performance of bitumen. It is essential to evaluate the aging behavior of bitumen to ensure better performance in the field. This study aims to determine the degree of aging by investigating the short-term aging behavior of commonly used bitumen in Bangladesh. A total of five randomly selected samples were collected for the characterization of bitumen, one of which was local and the rest were from foreign sources. A series of tests were conducted to determine elastic recovery, penetration, softening point, and ductility of the bitumen before and after aging. Short-term aging was carried out in the laboratory utilizing the rolling thin film oven. A wide range of variation in the degree of aging was observed for the similarly graded different bitumen samples. Based on the penetration test, sample BS-1 showed the highest degree of aging, with a value of 66.47%, while sample BS-2 had the lowest degree of aging, with a value of 46.82% among the collected bitumen samples. The significant variation observed in the degree of aging among the samples suggests that the field performance of bitumen is also likely to vary accordingly. The observed variation in performance matches the occurrence of pavement failures in our country. The findings of the study will direct engineers to be careful while selecting bitumen for road construction.