Abstract
The knowledge of the factors affecting the susceptibility of asphalt to aging can be of help when selecting the asphalt binders for the construction of durable pavements. Investigated were the aging-induced changes in the chemical composition and colloidal nature of asphalts differing in origin and technology. It was shown that the course of the changes in the generic composition of asphalt upon aging under laboratory conditions depends on the chemical type of the feedstock from which the asphalt has been derived. During aging of the asphalts from the paraffin–naphthenic crudes, the resins undergo partial decomposition, which results in the increase of the cyclic fraction content. Although the increase of the asphaltene content in air-blown asphalts after the Thin Film Oven Test was found to be lower than that in the corresponding straight-run asphalts, the much higher value of the instability index and smaller size distribution of asphaltenes in the air-blown asphalts permit us to expect that their utilization as binders in pavement construction will lead to the reduction of pavement durability. It follows from the results of this study that not only the generic composition but also the structure of the fractions affect the resistance of asphalt to aging.
Acknowledgment
The authors acknowledge the financial support of the Polish Committee for Scientific Research through Research Project 8 T07E 033 20.