Temperature Susceptibility and Rheological Aging Characteristics of the Bitumen Having Different Penetration Grades

Abstract

The performance of the asphalt pavement highly depends on the properties of the bitumen. Therefore, it is important to classify the bitumen’s characteristics in order to ensure the selected binder will provide the desired properties to the asphalt pavement. The Penetration grade, which categorizes the asphalt binder depending on the penetration value of the sample, is one of the most popular system for classification. Since the system considers the penetration value, the bituminous materials having different penetration grade is expected to have different physical, chemical and rheological properties. Within the scope of this study, four bitumen having different penetration grades as 50/70, 70/100, 150/200 and 160/220 were investigated by conventional and rheological analyses. The Penetration Index (PI) and the Rheological Aging Index (RAI) of the samples were calculated to evaluate the effects of penetration grade system on temperature susceptibility and rheological aging characteristics of the samples. As a result, the binders having lower penetration grades are found to be better in terms of rheological aging performance and temperature susceptibility. Furthermore, a very high correlation was found between RAI and PI values of the samples by statistical analysis.