Comparing Bitumen’s Molecular Weight Distribution Derived from Different Methods

ABSTRACT Although molecular weight distribution (MWD) is commonly employed to characterize bitumen properties, there remains a lack of knowledge concerning the advantages and disadvantages associated with various methods for determining the distribution. The present study seeks to compare the outcomes of MWD obtained through three distinct methods. Two of these methods rely on gel permeation chromatography (GPC), whereas the third is grounded in rheological investigations. Thirteen unique samples of neat bitumen, sourced from different origins, undergo testing and analysis. The findings reveal that, although minor discrepancies are evident among the different GPC methods, the results derived from rheological investigations exhibit significant inconsistencies. Specifically, the outcomes indicate lower average molecular weight values and distinct distribution shapes in the case of rheological investigations. Further refinements are needed to match the outcomes across the different methods.