Implementation of GPC characterization of asphalt binders at Louisiana materials laboratory : tech summary.

PDFTech ReportSIO No. 30000142LTRC Project No. 10-6BGel permeation chromatographyAsphalt cementCrumb rubberBindersPolymer asphaltSolventsLouisianaLouisiana Transportation Research CenterDaly, William H.Negulescu, IoanLouisiana Transportation Research CenterUS Transportation CollectionAsphalt is a mixture of a wide variety of chemical compounds that include aliphatic hydrocarbons and highly fusedaromatic ring systems. They are classi\uef\uac? ed as asphaltenes (medium molecular weight) and maltenes (low molecularweight). To improve the \uef\uac? nal properties of an asphalt binder, a high molecular weight polymer is added. In the case ofSBS (polystyrene-b-polybutadiene-b-polystyrene, a block copolymer) and SBR (polystyrene-polybutadiene rubber)polymer-modi\uef\uac? ed asphalt cements (PMACs), the polymer-modi\uef\uac? ed asphalt binder can be regarded as a true solutionin which the polymer is homogeneously blended with the components of the base asphalt cement. Because there is alarge di\uef\uac\u20ac erence between the molecular mass of polymer molecules and the mass of asphalt components (~ two orders ofmagnitude), the polymer can be easily visualized using a size exclusion analysis, such as gel permeation chromatography(GPC). As shown previously, the polymer and asphalt components of polymer-modi\uef\uac? ed asphalt cements can beseparated completely using gel permeation chromatography. It is of interest to apply GPC methodology to routinecharacterization of asphalt binders and to employ the technique in forensic analysis of paving problems