Increasing use of asphalt binders altered with elastomeric or plastic modifiers makes the specification of binders a difficult task.Ideally, a generic specification would allow various suppliers and additives to compete on the basis of expected performance differences in the hot-mix pavements resulting from the use of these binders. Unique characteristics of polymer-modified hot mix were investigated, and binder tests and properties that could be used to predict mix performance whether conventional or modified binders are used were determined. Two mix designs incorporating three conventional asphaltsand six different modified asphalts were tested in two phases. The objective was to determine which binder tests had promising correlations with important mix properties. Fraass point and pen-vis number showed the most promise for controlling temperature susceptibility of the hot mix at low temperatures. Penetration at 25 deg c and forceductility areas, particularly peak area, showed the most promise for predicting strength properties of mixes. The best prediction of fatigue life and permanent deformation, as measured by diametral testing, resulted from a combination of penetration at 25 deg c and forceductility area values as independent variables in multiple regression analysis. This paper appears in transportation research record no. 1269, Asphalt mix materials and mixtures 1990.
Abstract